Patent Application
20240261523
The present disclosure relates to systems for delivering respiratory support to a patient, and devices and systems that provide for integration of and switching between the function of respiratory apparatuses. It relates particularly but not exclusively to integration and switching between anaesthetic ventilation and high flow modes of respiratory support.
Patients may lose respiratory function during anaesthesia, or sedation, or more generally during certain medical procedures. Prior to a medical procedure a patient may be pre-oxygenated by a medical professional to provide a reservoir of oxygen saturation, and this pre-oxygenation and CO2 flushing/washout may be carried out with high flow respiratory support via a nasal cannula or other patient interface.
Once under general anaesthesia, patients must be intubated to ventilate the patient. In some cases, intubation is completed in 30 to 60 seconds, but in other cases, particularly if the patient's airway is difficult to traverse (for example, due to cancer, severe injury, obesity or spasm of the neck muscles), intubation will take significantly longer. While pre-oxygenation provides a buffer against declines in oxygen saturation, for long intubation procedures, it is necessary to interrupt the intubation process and increase the patient's oxygen saturation to adequate levels. The interruption of the intubation process may happen several times for difficult intubation processes, which is time consuming and puts the patient at serious health risk. After approximately three attempts at intubation the medical procedure, such as an intubation method will be abandoned.
High flow systems may be present in the operating theatre for use during anaesthetic or sedation procedures, or other medical procedures. High flow respiratory support has been found effective in meeting or exceeding the patient's normal inspiratory demand, to increase oxygenation of the patient, reduce the work of breathing or perform Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE). Pre-oxygenation using high flow systems prior to administration of anaesthesia or sedation provides an oxygen reservoir and extends safe apnoea time. Additionally, high gas flows may generate a flushing effect in the nasopharynx such that the anatomical dead space of the upper airways is flushed by the high incoming gas flows. This creates a reservoir of fresh gas available for each and every breath, while minimising re-breathing of carbon dioxide, nitrogen, etc. THRIVE is the provision of a high flow of respiratory gases to the patient when the patient is apnoeic, which occurs when the anaesthetic agents take effect and before the patient is successfully intubated and mechanically ventilated. High flow respiratory support refers to the delivery of heated and humidified respiratory gases to a patient via a non-sealing patient interface (e.g. nasal cannula) at high flow rates that when the patient is spontaneously breathing, are generally intended to meet or exceed inspiratory demand of a patient.
Once pre-oxygenated, anaesthetic agents are delivered to a patient to sedate the patient prior to intubation. Post intubation, anaesthetic agents are also delivered to maintain the anaesthetized state of the patient during a medical procedure. This delivery of anaesthetic agents can be done via injection or aerosols/vapor-the latter may be achieved by the use of an anaesthesia machine. A system configured for anaesthetic procedure typically includes an anaesthesia machine which includes a rebreathing system in which expired gases from the patient are returned to the machine. The anaesthesia machine provides the anaesthetic agents to sedate the patient and/or keep the patient sedated via a sealing mask placed on the patient. Once sedated, patients are intubated and then mechanically ventilated by the anaesthesia machine (anaesthetic ventilation) that assists or replaces spontaneous breathing.
A reference herein to a patent document or any other matter identified as prior art, is not to be taken as an admission that the document or other matter was known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims.
Currently high flow systems and anaesthetic machines are separate systems and there is no easy, effective and safe way to integrate both systems and/or their functionalities into anaesthetic practise. This creates difficulties in efficiently and safely transitioning from one form of respiratory support to another during medical procedures requiring use of both apparatuses. It would be useful to address or ameliorate one or more of these difficulties.
Viewed from one aspect, the present disclosure provides a system for delivering breathing gases to a patient, the system including:
Typically, in the second mode of operation, the breathing gases delivered to the patient exclude anaesthetic agents.
In some embodiments, when the first mode is selected, the system directs flow of breathing gases in a first inspiratory flow path in which a first patient interface directs breathing gases into an airway of the patient and is a sealing interface. Preferably, the first patient interface directs expired gases from the patient to an expiratory flow path which returns the expired gases to the first inspiratory flow path via the first respiratory apparatus. The first patient interface may be a sealing mask or an endotracheal tube.
In some embodiments, when the second mode is selected, the system isolates flow of breathing gases from the first respiratory apparatus to prevent delivery of anaesthetic agents to the patient. Preferably, when the second mode is selected, the system directs flow of breathing gases in a second inspiratory flow path in which a second patient interface directs the breathing gases into an airway of the patient and is a non-sealing interface such as a nasal cannula.
In some embodiments, the switching means includes a switching mechanism configured to alter flow of breathing gas in the system according to selection of the first mode of operation or the second mode of operation. The switching mechanism may be located between a gases supply and the first and second respiratory apparatuses. In some embodiments, the switching mechanism includes one or more gas flow valves.
In some embodiments, the switching mechanism includes a gas delivery apparatus receiving a supply of gases including NO, O2 and air and having one or more breathing gas outlets. The gas delivery apparatus may include one or more flow meters controlling flow rate of gases comprising one or more of NO, O2 and air through the one or more breathing gas outlets. The one or more flow meters may control flow of breathing gases through the one or more breathing gas outlets responsive to selection of the first mode of operation or the second mode of operation.
In some embodiments, the gas delivery apparatus includes a gas mixing element for combining NO, O2 and air in a proportion required for operation of the system in the first mode.
In some embodiments, the gas delivery apparatus includes a common gas outlet supplying breathing gas from the gas delivery apparatus to the first and second respiratory apparatuses. The gas delivery apparatus may include a first switching element coupled with the switching means and operable to control input to the common gas outlet wherein:
In some embodiments, the first respiratory apparatus and the second respiratory apparatus may be integrated in a unitary machine. The unitary machine may include a humidifier configured to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode. The humidifier may be located between the second respiratory apparatuses and the second patient interface.
In some embodiments, the gas delivery apparatus includes a gas mixing element for combining NO, O2 and air in a proportion required for operation of the system in the first mode or the second mode and may further include a flow meter for controlling flow rate of breathing gas from the gas mixing element. The gas delivery apparatus may include:
In some embodiments, the system further includes a second switching element coupled with the switching means and operable to control gas flow from the gas delivery apparatus to the first and second breathing apparatuses, wherein (i) when the first mode is selected, breathing gas from the gas delivery apparatus is directed only to the first gas outlet; and (ii) when the second mode is selected, breathing gas from the gas delivery apparatus is directed only to the second gas outlet.
In some embodiments, the gas delivery apparatus includes a first switching element operable to permit flow of breathing gases from the gas delivery apparatus to the first respiratory apparatus when the first mode is selected. The second respiratory apparatus may include a flow meter receiving a supply of gases including O2 for delivery at the predetermined flow rate; and the system may include a second switching element operable to permit flow of breathing gases from the flow meter to the second patient interface when the second mode is selected. The first and second switching elements may be operably coupled such that when the second mode is selected, the first switching element prevents flow of breathing gases from the gas delivery apparatus to the first respiratory apparatus and the second switching element permits flow of breathing gases from the flow meter to the second patient interface.
In some embodiments, the switching mechanism includes a gas diverter receiving a supply of gases including an anaesthetic gas and a breathing gas, the gas diverter having first and second switching elements operable to control flow of gases from the gas diverter to the first and second respiratory apparatuses according to selection of a first mode of operation or a second mode of operation of the system. The first switching element may include a valve controlling flow of anaesthetic gas which is open in the first mode and closed in the second mode. The second switching element may include one or more diverter valves which direct breathing gas to the first respiratory apparatus in the first mode and direct breathing gas to the second respiratory apparatus in the second mode.
In some embodiments, the switching mechanism includes: (a) a first switching element operable to direct flow of O2 to the first respiratory apparatus in the first mode and to the second respiratory apparatus in the second mode; and (b) a second switching element which is responsive to the first switching element, and operable to stop flow of gas from the first apparatus to the patient when the first switching element is operated in the second mode. The first switching element may be e.g. a diverter valve.
In some embodiments, the first respiratory apparatus and the second respiratory apparatus are separate machines. The second respiratory apparatus may include a humidifier configured to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode.
In some embodiments, the first switching element and the second switching element are operatively coupled for substantially simultaneous operation with or following operation of the switching means. In other embodiments, the switching means incorporates the first and second switching elements.
In some embodiments, the predetermined flow rate is selectable from an available range of from about 20 L/min to about 90 L/min by the user operating the switching means. In some embodiments, the pre-determined flow rate is selectable by the user from a plurality of pre-determined available flow rates. The pre-determined available flow rates may include at least e.g.: 0 L/min, 40 L/min and 70 L/min.
In some embodiments, the switching means is operable by the user to select delivery of the selected pre-determined flow rate in a continuous flow or oscillating flow. The switching means may include a rate selector operable by the user to control selection and/or delivery of the pre-determined flow rate in the second mode of operation. In some embodiments, operation of the rate selector prevents delivery to the patient of breathing gases from the first respiratory apparatus. In some embodiments, operation of the rate selector to select a rate of 0 L/min permits supply of O2 to the first respiratory apparatus, otherwise operation of the rate selector prevents delivery of anaesthetic agents from the first respiratory apparatus to the patient.
In some embodiments, the switching means includes a pressure-controlled actuator configured to permit flow of breathing gases in the first respiratory apparatus in response to an increase in breathing gas pressure in a flow to the second respiratory apparatus. In some embodiments, the switching means includes a pressure-controlled actuator configured to prevent flow of breathing gases in the first respiratory apparatus in response to a decrease in breathing gas pressure in a flow to the second respiratory apparatus.
In some embodiments, the switching means further provides for selection by the user of a manual first mode of operation or a mechanical first mode of operation of the first respiratory apparatus. For example, the switching means may include a 3-way actuator which provides for selection by the user of manual first mode, mechanical first mode or second mode of operation. Selection of the mechanical first mode may trigger connection by the system of a mechanical ventilator circuit with the first respiratory apparatus. Selection of the manual first mode may trigger connection by the system of a ventilator bag with the first respiratory apparatus.
In some embodiments, selection of the second mode of operation causes the system to substantially simultaneously: (i) prevent flow of breathing gases from the first respiratory apparatus to the patient through a first inspiratory flow path; and (ii) provide a flow of breathing gases from the second respiratory apparatus to the patient through a second inspiratory flow path.
In some embodiments, the system includes a controller receiving inputs from one or more sensors for detecting if a breathing circuit coupled with the patient's airway is associated with a first patient interface for use with the first respiratory apparatus or a second patient interface for use with the second respiratory apparatus, wherein the controller operates the switching means to select the mode of operation according to the detected association of the breathing circuit.
The one or more sensors may include e.g. a pressure sensor arranged to measure back pressure in the first and/or second respiratory apparatuses, wherein the controller determines the breathing circuit to be associated with the first patient interface when the measured back pressure indicates breathing gas is delivered to the patient by a substantially sealed patient interface. Alternatively or additionally, the one or more sensors may include a CO2 sensor associated with one or each of a first breathing circuit associated with the first patient interface and a second breathing circuit associated with the second patient interface, wherein the controller determines the breathing circuit in which expired gas from the patient contains high concentration of CO2 to be the breathing circuit through which breathing gas is delivered to the patient. Alternatively or additionally, the sensor may include a proximity sensor.
In some embodiments, the switching means includes one or more actuators operable by a user, the one or more actuators including one or more of: a button, switch, knob, electronic input device, touch screen, voice activated sensor, and foot operated switch. One or more actuators may be located at or near a patient interface through which breathing gas is delivered to the patient by the first respiratory apparatus or the second respiratory apparatus. In some embodiments, the one or more actuators includes an electronic input device wirelessly couplable with a controller of the system and locatable at multiple positions with respect to the patient and/or the first and second breathing apparatuses.
The switching means may include one or more switching mechanisms which may include one or more mechanical, electronic, electromechanical, and pneumatic switching mechanisms. In some embodiments, the one or more switching mechanisms are couplable with the switching means via one or more of wired coupling and wireless coupling. The switching mechanisms may be operable to control one or more characteristics of breathing gases delivered to the subject, said characteristics selected from a group including presence of volatiles, flow rate, gas composition, gas concentration, temperature, and/or humidity.
In some embodiments, the second respiratory apparatus is configured to deliver a flow of breathing gas at the predetermined flow rate being in a range of about 20-90 L/min.
In some embodiments, operation of the system in the second mode precludes delivery of anaesthetic agents in breathing gas delivered to the patient. This may be achieved using any suitable means.
The first respiratory apparatus may include one or more of a CO2 absorber configured to treat returned expired gas before recirculating to the patient in the first mode, a pressure limiting valve configured to maintain substantially stable pressure in the system in the first mode, a variable volume for displacement of gases in the first mode, a fresh gas flow for replenishing anaesthetic gas delivered to the patient in the first mode and vaporizer for vaporizing volatile anaesthetic agents into breathing gas delivered to the patient in the first mode.
The second respiratory apparatus may include one or more of a flow source configured to generate gas flows through the system and a humidifier configured to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode.
Viewed from another aspect, the present disclosure provides a gas delivery device for use with a respiratory system, the gas delivery device including: (a) a first inlet receiving a supply of anaesthetic gas; (b) a second inlet receiving a supply of a breathing gas; (c) a first outlet; (d) a second outlet; and (e) a manifold between the first and second inlets and the first and second outlets, the manifold providing a first flow path to the first outlet and a second flow path to the second outlet; wherein the gas delivery device is operable in: (i) a first configuration the first flow path is open and the second flow path is closed; and (ii) a second configuration in which the second flow path is open and the first flow path is closed.
In some embodiments, in the first configuration, the gas delivery device prevents flow of anaesthetic gas to the outlets. A first valve may control flow of anaesthetic gas in the manifold, wherein the first configuration the first valve is open and directs anaesthetic gas to the first flow path, and in the second configuration the first valve is closed. A second valve may control flow of breathing gas in the manifold, wherein in the first configuration the second valve directs breathing gas to the first flow path, and in the second configuration the second valve directs breathing gas to the second flow path. One or both of the first and second valves may be operable to control rate of flow of gas therethrough.
In some embodiments, the gas delivery device includes a third inlet receiving a supply of a further breathing gas, wherein the breathing gases supplied to the second and third inlets include air and O2. The second valve may be operable to control O2 concentration in breathing gas delivered to the first and second flow paths.
In some embodiments, the gas delivery device is operable in a third configuration in which both the first flow path and the second flow path are open.
In some embodiments, the gas delivery device includes switching means operable by a user to select a configuration for operation of the gas delivery device. The switching means may be pneumatic, mechanical, electronic or a combination of these.
In some embodiments, the gas delivery device may be configured for connection to a power source. In some embodiments, the gas delivery device may include a battery.
In some embodiments, the first outlet of the gas delivery device may be couplable with a first respiratory apparatus gas inlet. The first respiratory apparatus may be e.g. an anaesthesia machine. In some embodiments, the second outlet of the gas delivery device may be couplable with second respiratory apparatus gas inlet. The second respiratory apparatus may be e.g. a high flow respiratory apparatus.
The gas delivery device may include one or more switching elements for creating the first and second flow paths. A switching element may be located on the first respiratory apparatus. A switching element may be located on the second respiratory apparatus. A switching element may be located on a patient interface through which breathing gas is directed into an airway of the patient. A switching element may be activated responsive to detection of a change in state detected by one or more system sensors. A system sensor may include one of a pressure sensor, CO2 sensor, O2 sensor, flow sensor, gas concentration sensor etc. A switching element may be in wired or wireless communication with one or more other switching elements to control operation of the gas delivery device according to the configuration selected by the user.
In some embodiments, the gas delivery device includes an output module providing one or both of a visible and audible indication of the configuration in which the gas delivery device is operating. Operation of the output module may be activated e.g. when the switching means is operated by the user to select the second configuration.
In some embodiments, the gas delivery device includes a gas mixer for combining received gases in a proportion required to deliver a required therapy.
Viewed from another aspect the present disclosure provides a respiratory apparatus operable to deliver breathing gases to a patient in a plurality of modes, the respiratory apparatus providing an inspiratory gas flow path and an expiratory gas flow path, wherein: (a) in a first mode, the respiratory apparatus delivers breathing gases including one or more anaesthetic agents to the inspiratory gas flow path and receives return of expired gases via the expiratory gas flow path; (b) in a second mode, the respiratory apparatus disables flow of one or more anaesthetic agents and delivers breathing gases including O2 to the inspiratory gas flow path at a pre-determined flow rate without return of expired gas; and (c) in a transient mode, the respiratory apparatus disables flow of one or more anaesthetic agents and delivers a high flow of O2 to the inspiratory gas flow path.
The respiratory apparatus may include a switching means operable to select one of the modes of operation from the plurality of modes.
In some embodiments, the transient mode is activated only during operation of an actuator that is normally biased off. The respiratory apparatus may include a button or trigger configured to be activated by a user to operate the respiratory apparatus in the transient mode, wherein release of the button or trigger disables the transient mode.
In some embodiments, in the first mode, the respiratory apparatus is operable to deliver breathing gases including anaesthetic agents to the patient by a first patient interface forming a sealed interface with the patient's airway and returning expired gases to respiratory apparatus by the expiratory gas flow path. The first patient interface may be a mask or endotracheal tube.
In some embodiments, in the second mode, the respiratory apparatus is operable to deliver breathing gases to the patient by a second patient interface forming an unsealed interface with the patient's airway. The second patient interface may be e.g. a nasal canula.
In some embodiments, the respiratory apparatus is operable in a manual first mode of operation or a mechanical first mode of operation. The respiratory apparatus may include a switching means operable by a user for selection of manual first mode, mechanical first mode or second mode of operation. In some embodiments, selection of the manual first mode triggers connection of a manual ventilation bag with the first respiratory apparatus.
In some embodiments, the respiratory apparatus is configurable in gas flow communication with one or more of: a CO2 absorber configured to treat returned expired gas before recirculating to the patient in the first mode; a pressure limiting valve configured to maintain substantially stable pressure in the system in the first mode; a variable volume for displacement of gases in the first mode; a fresh gas flow for replenishing anaesthetic gas delivered to the patient in the first mode; and a vaporizer for vaporizing volatile anaesthetic agents into breathing gas delivered to the patient in the first mode.
In some embodiments, the respiratory apparatus is configurable in gas flow communication with one or more of: a flow source configured to generate gas flows through the system; and a humidifier configured to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode.
Viewed from another aspect the present disclosure provides a system for delivering breathing gases to a patient, the system receiving a supply of breathing gases for delivery to the patient by an inspiratory gas flow path and couplable with a returned gas conduit returning expired gases from the patient, the system including: a flow generator configured to generate gas flows through the system; and a switching actuator operable to select a mode of operation of the system; wherein the system is operable in a first mode in which breathing gases are delivered in a closed gas flow circuit in which expired gases are returned to the system for rebreathing by the patient, and in a second mode in which breathing gases are delivered in an open gas flow circuit without rebreathing.
In some embodiments, the flow generator is a blower operable to deliver gas flows at flow rates that are compatible with delivering respiratory therapies including anaesthesia, ventilation and high flow respiratory support. The flow generator may be operable to deliver gas flows in a range of up to about 90 L/min.
In some embodiments, the switching actuator is operatively coupled with the flow generator, and operation of the switching actuator to select the first mode causes operation of the flow generator at a low flow rate such as less than 15 L/min.
In some embodiments, the switching actuator includes or is operatively coupled with a switching mechanism, and in the first mode the switching mechanism permits a first flow of fresh breathing gas to the system and permits return of expired gases to the system, and in the second mode the switching mechanism permits the first flow of fresh breathing gas into the system and prevents return of expired gases to the system. The switching mechanism may include any suitable mechanism such as e.g. a gas flow diverter or a pressure-controlled gas flow diverter.
In some embodiments, the switching mechanism is located upstream of the flow generator.
In some embodiments, the switching mechanism is operatively coupled with the flow generator, and operation of the switching mechanism in the first mode causes operation of the flow generator at a low flow rate.
The second mode may include a ventilator mode and a high flow mode.
In some embodiments, operation of the switching actuator to select high flow mode causes operation of the flow generator at a flow rate sufficient to deliver high flow respiratory support. In some embodiments, operation of the switching actuator to select ventilator mode causes operation of the flow generator at a flow rate consistent with patient ventilation.
In some embodiments, the system is configured to receive a supply of anaesthesia gases for delivery to the patient in the inspiratory gas flow path in the first mode. The system may include a pressure limiting valve to maintain substantially stable gas pressure in the system. The system may be configured to receive a supply of anaesthesia gases downstream of the flow generator or upstream of the flow generator. The returned gas conduit may be couplable with the system downstream of the flow generator.
In some embodiments, the system includes a gas flow reflector which may be configured e.g. to collect anaesthetic gases expired from the patient and return them to the inspiratory gas flow path in a following inhalation phase.
The system may be configured to prevent supply of anaesthesia gases to the system when the second mode is selected.
The system may include a CO2 absorber configured to treat returned expired gases before recirculating to the inspiratory gas flow path in the first mode. Alternatively or additionally the system may include a humidifier configured to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode.
Viewed from another aspect, the present disclosure provides a system for delivering breathing gases to a patient, the system being operable in a first mode and a second mode, wherein the first mode includes a recirculating gases flow between the system and the patient's airway, and the second mode includes a non-recirculating gases flow between the system and the patient's airway, the system including: (a) first module including a first set of respiratory components; and (b) a second module including a second set of respiratory components, the second module configured to cooperate with the first module to switch between the two modes; wherein the system is operable in the first mode when the first module is activated or coupled together with the second module, and the system is operable in the second mode when the first module is inactivated or uncoupled from the second module.
In the first mode, gases delivered to the patient in the recirculating gases flow may include an anaesthetic agent.
The first set of respiratory components may include one or more of a CO2 absorber configured to treat returned expired gas before recirculating to the patient in the first mode, a pressure limiting valve configured to maintain substantially stable pressure in the system in the first mode, a variable volume for displacement of gases in the first mode, a fresh gas flow for replenishing anaesthetic gas delivered to the patient in the first mode, and a vaporizer for vaporizing volatile anaesthetic agents into breathing gas delivered to the patient in the first mode.
The second set of respiratory components may include one or more of a flow source configured to generate gas flows through the second set of respiratory components, an inspiratory conduit, a patient interface configured to direct gases from the non-recirculating gases flow to the patient's airway, a humidifier configured to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode and a filter upstream of the patient interface.
The first module may include a first gases outlet and a first gases inlet, and the second module includes a second gases inlet and a second gases outlet, wherein the first gases outlet is couplable with the second gases inlet and the first gases inlet is couplable with the second gases outlet.
In some embodiments, operation of the system in the first mode permits a first flow of fresh breathing gas to the system and permits return of expired gases to the system, and the second mode permits the first flow of fresh breathing gas into the system and prevents return of expired gases to the system.
In some embodiments, operation of the system in the second mode prevents release of anaesthetic agents from the system. The second mode may include a ventilator mode and a high flow mode.
The second module may be configured to receive a supply of breathing gas independently of the first module.
Viewed from another aspect, the present disclosure provides a system for delivering breathing gases to a patient, the system including: a flow source configured to generate gas flows through the system in a gas delivery circuit; and a switching mechanism forming part of the gas delivery circuit; wherein the gas delivery circuit has an inspiratory gas flow path and an expiratory gas flow path, and the switching mechanism is configured to switch between gas flow paths in the gas delivery circuit according to selection of a first mode of operation in which the inspiratory gas flow path is in fluid communication with a first patient interface, or a second mode of operation in which the inspiratory gas flow path is in fluid communication with a second patient interface.
The first patient interface may form a substantially sealing interface with the patient's airway and receives expiratory gas from the patient. The second patient interface may form a non-sealing interface with the patient's airway.
In some embodiments, the switching mechanism includes one or more of a gas flow diverter, bi-stable switch, pneumatic switch, rotary switch, lever, knob or other actuator which is operable by the user. The switching mechanism may be operable by a user to switch between inspiratory and expiratory gas flows in the gas delivery circuit.
In some embodiments, the system includes one or more sensors configured to monitor one or more characteristics of gas in the gas delivery circuit, and controls operation of the flow generator based on said one or more monitored characteristics. The characteristics may indicate one or more of e.g. flow, pressure and CO2 to name a few. In some embodiments, the system controls operation of the flow source to generate low flows when the one or more sensors indicate breathing gas flow is to the first patient interface. In some embodiments, the system controls operation of the flow generator to generate high flows when the one or more sensors indicate breathing gas flow is to the second patient interface.
In some embodiments, the system is configured to receive a user input to select the first mode of operation in which the flow source generates a low flow rate below a pre-determined flow rate, or the second mode of operation in which the flow source generates a high flow rate at or above the pre-determined flow rate, wherein the switching mechanism operates responsive to flow rate of gas in the inspiratory gas flow path as generated by the flow source. The switching mechanism may direct flow to the first patient interface in response to low flow rate of gas in the inspiratory gas flow path. The switching mechanism may direct flow to the second patient interface in response to high flow rate of gas in the inspiratory gas flow path.
In some embodiments, the switching mechanism is provided by operation of the first and second patient interfaces in which a first mode of delivery is selected when the first and second patient interfaces are applied to the patient simultaneously, and wherein the second mode of delivery is selected when only the second patient interface is applied to the patient. In some embodiments, the first patient interface is a sealing face mask, and the second patient interface is a nasal cannula adapted to operate including while the sealing face mask is applied over the nasal cannula. Thus the first patient interface may be a mask configured to form a sealing interface over the second patient interface which is a nasal cannula. In some embodiments, the sealing face mask is not operable when the sealing face mask is not applied over the nasal cannula and the second mode of delivery is enabled when only the nasal cannula is applied to the patient.
In some embodiments, simultaneous use of the first and second patient interfaces in the first mode, directs inspiratory gas flow to the patient by one or both of the first and second patient interfaces and returns expiratory gas from the first patient interface to the expiratory gas flow path.
In some embodiments, the first patient interface is in fluid communication with an anaesthetic gas reflector.
In some embodiments, the system includes one or more of a CO2 absorber configured to treat returned expired gas before recirculating to the patient in the first mode, a pressure limiting valve configured to maintain substantially stable pressure in the system in the first mode, a variable volume for displacement of gases in the first mode, a fresh gas flow for replenishing anaesthetic gas delivered to the patient in the first mode and a vaporizer for vaporizing volatile anaesthetic agents into breathing gas delivered to the patient in the first mode.
In some embodiments, the system includes one or more of a flow source configured to generate gas flows through the system, and a humidifier configured to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode.
Viewed from another aspect, the present disclosure provides a switching mechanism forming part of a gas delivery circuit delivering breathing gases to a patient, the switching mechanism being configured to switch between inspiratory and expiratory gas flow paths in the gas delivery circuit according to selection of a first mode of operation in which the inspiratory gas flow path is in fluid communication with a first patient interface, or a second mode of operation in which the inspiratory gas flow path is in fluid communication with a second patient interface.
In some embodiments, the switching mechanism may be operable by a user, and may include one or more of: a gas flow diverter, pneumatic switch, rotary switch, lever, knob or other actuator which is operable by the user.
In some embodiments, the switching mechanism may operate responsive to a flow rate of gas in the inspiratory flow path, wherein a high flow rate of gas results in selection of the second mode of operation. In some embodiments, the switching mechanism may be configured to operate responsive to a flow rate of gas in the inspiratory flow path, wherein a low flow rate of gas switches the switching mechanism to the first mode of operation and wherein a high flow rate of gas switches the switching mechanism to the second mode of operation.
Viewed from another aspect, the present disclosure provides a multi-lumen assembly for use with a respiratory support system, the multi-lumen assembly having a plurality of conduits including: (a) a first inspiratory conduit having a first conduit inflow end couplable with a first gas outlet of the respiratory support system; (b) a second inspiratory conduit having a second conduit inflow end couplable with a second gas outlet of the respiratory support system; and (c) an expiratory conduit having an expiratory conduit outflow end couplable with an expired gas inlet of the respiratory support system.
The first inspiratory conduit may have a first conduit outflow end couplable with a first patient interface configured to sealingly engage with and direct flow into an airway of the patient. The second inspiratory conduit may have a second conduit outflow end couplable with a second patient interface configured to direct flow into an airway of the patient and is a non-sealing interface.
In some embodiments, at least a length of the plurality of conduits may be arranged co-axially.
A mechanism may be provided retain at least a length of the plurality of conduits in a group. The mechanism may include a webbing arranged between at least pairs of the plurality of conduits at intervals or continuously along at least a length of the plurality of conduits. The webbing may be frangible to facilitate separation of at least a length of one or more of the plurality of conduits from the group. Alternatively or additionally the mechanism may include a sheath applied around the plurality of conduits. Part of the sheath may be removeable. The sheath may provide a smooth outer surface. Alternatively or additionally the mechanism may include one or more retainers configured to retain two or more conduits in the plurality of conduits in a group. The retainers may be slidable along a length of one of more of the conduits in the plurality of conduits.
In some embodiments, the first inspiratory conduit may be configured to deliver breathing gases including an anaesthetic agent to the patient. The expiratory conduit may be configured to return expired gases from the patient to the respiratory support system. The second inspiratory conduit may be configured to deliver breathing gases to the patient at a flow rate between 20 L/min and 90 L/min.
In some embodiments, the multi-lumen assembly may include or cooperate with a flow switching mechanism operable to direct flow of breathing gas into the first inspiratory conduit or into the second inspiratory conduit. The flow switching mechanism may be a flow diverter. The flow switching mechanism may be operable by a user. Alternatively or additionally the flow switching mechanism may be operatively linked with a respiratory support system controller. In some embodiments, the respiratory support system controller controls the respiratory support system to deliver breathing gases to the multi-lumen assembly according to operation of the flow switching mechanism by the user. The respiratory support system controller may control operation of the flow switching mechanism.
In some embodiments, the outflow end of the first inspiratory conduit and an inflow end of the expiratory conduit form a common gas flow pathway defined by a single gas exchange conduit which is couplable with a first patient interface. A taper may be provided to reduce the overall cross section of the multi-lumen assembly in a region of the single gas exchange conduit.
In some embodiments, the multi-lumen assembly includes a patient-end connector for coupling: (a) an outflow end of the first inspiratory conduit with a first patient interface; and (b) an outflow end of the second inspiratory conduit with a second patient interface. The patient end connector may include a switching element operable to switch the connector between a first mode of operation in which the connector directs breathing gas to the first patient interface, and a second mode of operation in which the connector directs breathing gas to the second patient interface. The switching element may be operatively couplable with a respiratory support system controller. Alternatively or additionally, the switching element may be operable by a user, and the controller controls operation of the respiratory support system according to operation of the switching element by the user. In some embodiments, the respiratory support system controller controls operation of the switching element.
In some embodiments, the multi-lumen assembly may include a gas sampling conduit for monitoring one or more characteristics of gas. The characteristics may be used by a respiratory support system controller to determine if the connector is delivering breathing gas to the patient in the first inspiratory conduit or the second inspiratory conduit and the controller may operates the respiratory support system to automatically select a corresponding mode of operation of the respiratory support system.
Viewed from another aspect, the present disclosure provides a breathing gas connector for use with a respiratory support system delivering breathing gases to a patient, the connector having: (a) an inlet port couplable with a gas flow conduit receiving breathing gases from the respiratory support system; (b) a first outlet port couplable with a first gas flow path delivering breathing gas to the patient through a first patient interface; (c) a second outlet port couplable with a second gas flow path delivering breathing gas to the patient through a second patient interface; and (d) a switching mechanism operable to switch the connector between a first mode of operation the in which the connector directs gas from the inlet port to the first outlet port and a second mode of operation in which the connector directs gas from the inlet port to the second outlet port.
In some embodiments, the connector may include an expiratory gases port couplable with an expiratory gas conduit, wherein in the first mode, the switching mechanism directs expired gases in the first gas flow path to the expiratory gases conduit.
The switching mechanism may be operatively couplable with a controller of the respiratory support system, wherein operation of the connector switching mechanism may select: (a) the first mode of operation causes the controller to operate the respiratory support system in a first mode in which breathing gases including an anaesthetic agent are delivered to a gas flow conduit coupled with the connector; (b) the second mode of operation causes the controller to operate the respiratory support system in a second mode in which breathing gases are delivered at a pre-determined flow rate to a gas flow conduit coupled with the connector.
In some embodiments, the connector switching mechanism may be operatively couplable with a controller of the respiratory support system such that operation of the connector switching mechanism to select the second mode of operation causes the controller to prevent flow of anaesthetic agents in the breathing gas.
In some embodiments, the connector may include a sensor detecting one or more characteristics of gas at the first outlet port or the second outlet port, said characteristics being used to determine if the connector is coupled to the patient's airway by a first patient interface or a second patient interface, the sensor providing input to a controller of the respiratory support system which automatically selects a corresponding mode of operation of the respiratory support system. The one or more characteristics include e.g. gas pressure, CO2 concentration and gas flow rate.
In some embodiments, a sensor wire may be locatable inside a conduit providing a gas flow path between the sensor and the respiratory support system controller.
Viewed from another aspect, the present disclosure provides a controller for use with a respiratory support system delivering breathing gases to a patient via a multi-lumen assembly, the controller including: (a) a control interface operable to receive a selection by a user of a first mode of operation or a second mode of operation of the respiratory support system; (b) a tube assembly input connector for coupling with a patient end of the multi-lumen assembly having a first inspiratory conduit, a second inspiratory conduit and an expiratory conduit; (c) a first flow port couplable with a first flow path delivering breathing gases to the patient in a first mode; and (d) a second flow port couplable with a second flow path delivering breathing gases to the patient in a second mode.
In some embodiments, the controller may include a switching mechanism configured to direct breathing gas from the first inspiratory conduit to the first flow port when the first mode is selected, and to direct breathing gas from the second inspiratory conduit to the second flow port when the second mode is selected.
In some embodiments, the controller may include a third flow port couplable with an expiratory flow path receiving expired gases from the patient in the second mode. The switching mechanism may be configured to direct expired gases to the third flow port when the second mode is selected.
In some embodiments, the controller may include a mounting means configured to releasably attach the controller to a structure located in close proximity to the patient.
In some embodiments, the control interface may be operatively linked with a respiratory support system controller. The respiratory support system controller may control the respiratory support system to deliver breathing gases to a multi-lumen such as described above according to a mode of operation selected using the control interface. In some embodiments, the respiratory support system controller is operable to control operation of the control interface. The controller may be provided for use with the multi-lumen assembly as described above.
Viewed from another aspect, the present disclosure provides a system for delivering breathing gases to a patient, the system being operable to deliver breathing gases in a first mode through a first patient interface, and in a second mode through a second patient interface, the system including: (a) one or more CO2 sensors configured to detect CO2 in expired gas from the patient; (b) a switching mechanism for switching between the first and second modes according to detected CO2; and (c) a system controller receiving an input from the one or more CO2 sensors; wherein the system controller operates the switching mechanism to select the first mode or the second mode.
In some embodiments, the switching mechanism is operable to switch modes when at least predetermined threshold of CO2 is detected. The threshold may be e.g. about equivalent to CO2 concentration of ambient air.
The one or more switching mechanisms includes one or more mechanical, electronic, electromechanical, and pneumatic switching mechanisms. The one or more switching mechanisms may couplable with the system controller via a wired coupling and/or a wireless coupling.
In some embodiments, in the first mode breathing gases are delivered to the patient's airway through the first patient interface which may be a sealing interface such as e.g. a sealing mask or endotracheal tube, and expired gases are returned to the system by an expiratory gas flow path. The first mode may include a rebreathing mode in which expired gases returned to the system are recirculated for delivery to the patient via the first patient interface. The breathing gases may include one or more anaesthetic agents. In some embodiments, the CO2 sensor detects CO2 in expired gases in the expiratory gas flow path.
In some embodiments, the second mode is a high flow mode wherein breathing gases are delivered to the patient at a predetermined flow rate through the second patient interface, which is a non-sealing interface such as e.g. a nasal cannula. The CO2 sensor may detect CO2 in expired gases at the second patient interface as they exit the patient's airway. In some embodiments, the CO2 sensor may be located on the nasal cannula to detect CO2 in expired gas exiting one or both of the patient's nares.
In some embodiments, the system includes a first respiratory apparatus delivering breathing gases in the first mode, and a second respiratory apparatus delivering breathing gases in the second mode. When the second mode is selected, the system may isolate flow of breathing gases from the first respiratory apparatus to the patient. In some embodiments the first respiratory apparatus and the second respiratory apparatus may be integrated in a unitary machine although that need not be the case. In some embodiments, the system may include a humidifier configured to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode.
In some embodiments, the second respiratory apparatus delivers breathing gases at a predetermined flow rate and optionally, the predetermined flow rate may be selectable from an available range of from about 20 L/min to about 90 L/min by operating the switching means.
In some embodiments, the system includes a CO2 sensor associated with one or each of a first breathing circuit for delivery of breathing gases in the first mode and a second breathing circuit for delivery of breathing gases in the second mode. The controller may determine the breathing circuit containing highest concentration of CO2 to be the breathing circuit through which breathing gas is to be delivered to the patient and controls delivery of gases to the determined breathing circuit according to the relevant mode of operation.
In some embodiments, the system includes a display device in operative communication with the system controller and configurable to display one or more C CO2 O2 traces based on inputs from the one or more CO2 sensors received by the system controller. The system controller may be configured to automatically cause display of a single CO2 trace corresponding to the CO2 sensor input representing the highest detected CO2 values from the plurality of CO2 sensors.
In some embodiments, the first respiratory apparatus may include one or more of: a CO2 absorber configured to treat returned expired gas before recirculating to the patient in the first mode, a pressure limiting valve configured to maintain substantially stable pressure in the system in the first mode, a variable volume for displacement of gases in the first mode, a fresh gas flow for replenishing anaesthetic gas delivered to the patient in the first mode and a vaporizer for vaporizing volatile anaesthetic agents into breathing gas delivered to the patient in the first mode.
In some embodiments, the second respiratory apparatus may include one or more of: a flow source configured to generate gas flows through the system, and a humidifier configured to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode.
Viewed from another aspect the present disclosure provides a system for delivering breathing gases to a patient, the system including: (a) a flow source configured to provide gas flows through the system in a gas delivery circuit; and (b) a gas delivery conduit circuit including an inspiratory gas flow path and an expiratory gas flow path, the system configured to switch between a first mode and a second mode. In the first mode, the system is operable to deliver the breathing gases to the patient via the inspiratory gas flow path and a first patient interface in fluid communication with the inspiratory flow path, and to deliver expiratory gases from the patient via the expiratory gas flow path and a second patient interface in fluid communication with the expiratory gas flow path, the breathing gases including a first flow parameter. In the second mode, the system is operable to deliver the breathing gases to the patient via the inspiratory gas flow path and a third patient interface, the breathing gases including a second flow parameter.
In some embodiments, the first flow parameter is different from the second flow parameter. The first flow parameter may include a first flow rate and the second flow parameter may include a second flow rate, wherein the first flow rate is less than the second flow rate. In some embodiments, the first flow rate is less than 15 L/min and the second flow rate is greater than 15 L/min. In some embodiments, the second flow rate is in the range of between about 20 L/min and between about 90 L/min, optionally about 40 L/min and about 70 L/min.
The first patient interface may include a non-sealing patient interface, such as e.g. a nasal cannula, and the second patient interface may include a sealing patient interface, such as e.g. a mask. The third patient interface may include a non-sealing patient interface, such as e.g. a nasal cannula. In some embodiments, the first and third patient interfaces are the same.
In some embodiments, the expiratory flow path is inoperable in the second mode.
In some embodiments, the system is in the first mode when the first and second patient interfaces are applied simultaneously to the patient and is in the second mode when only the third patient interface is applied to the patient. The first and third patient interfaces may include a non-sealing nasal cannula and the second patient interface may include a sealing mask, and the system may be in the first mode when the nasal cannula and mask are applied to the patient and the system may be in the second mode when only the nasal cannula is applied to the patient. In some embodiments, the mask is configured to seal over the nasal cannula and with the patient.
In some embodiments, the system includes a third mode and a fourth patient interface and the system may be configured to deliver the breathing gases to the patient via the inspiratory gas flow path and the fourth patient interface and to deliver expiratory gases from the patient via the expiratory gas flow path and the fourth patient interface. The breathing gases may include a third flow parameter. The fourth patient interface may include a sealing patient interface, such as e.g. an invasive patient interface, laryngeal mask airway or endotracheal tube.
In some embodiments, the first flow parameter includes a pressure and/or volume parameter.
In some embodiments, the third flow parameter include one or more of a flow rate, pressure or volume parameter.
In some embodiments, the system may be configured to control the delivery of breathing gases to the patient based on pressure and/or volume.
In some embodiments, system includes an inspiratory conduit defining at least a portion of the inspiratory gas flow path and an expiratory conduit defining at least a portion of the expiratory gas flow patient, and a common connector provided at an end of the inspiratory and expiratory conduits, the common connector configured to connect to the one or more patient interfaces.
In some embodiments, the system includes a controller in communication with the flow source, and one or more of a sensor or an input interface in communication with the controller to provide an input to the controller to control the flow source to provide flow of breathing gases in the first or second mode. The sensor and/or input interface may be configured to provide an input to the controller to control the flow source to provide flow of breathing gases in the third mode.
In some embodiments, the system includes a humidifier, wherein the breathing gases are heated and humidified by the humidifier in the second mode prior to being delivered to the patient.
In some embodiments, the expiratory gases from the patient are returned to the inspiratory gas flow path in the first mode. In some embodiments, the expiratory gases from the patient are returned to the inspiratory gas flow path in the third mode. In some embodiments, the system including a CO2 remover configured to remove CO2 from the expiratory gases before returning the expiratory gases to the inspiratory gas flow path.
When a high flow system and anaesthesia machine are integrated, it may be desirable to have a configuration that allows for easy and sufficient humidification of breathing gases that are delivered during high flow respiratory support. It may also be desirable to enable humidification of the breathing gases in the high flow mode.
Viewed from another aspect, the present disclosure provides a respiratory apparatus for delivering breathing gases to a patient, the respiratory apparatus including: a flow source for providing a flow of breathing gases in an inspiratory flow path for delivery to the patient; a mount for coupling with at least one vaporizer for vaporizing one or more volatile anaesthetic agents into the flow of breathing gases in the inspiratory flow path before delivery to the patient; and a return path for recirculating expired gases received from the patient via an expiratory flow path to the inspiratory flow path; wherein the mount is couplable with a humidification component for conditioning the flow of breathing gases in the inspiratory flow path to a pre-determined temperature and/or humidity before delivery to the patient.
In some embodiments, operation of the humidification component prevents delivery of the one or more volatile anaesthetic agents into the flow of breathing gases in the inspiratory flow path. Operation of the humidification component may disable operation of the at least one vaporizer.
In some embodiments, the respiratory apparatus further includes an interlocking mechanism to prevent simultaneous operation of the humidification component and the at least one vaporizer. The interlocking mechanism may be configured to enable operation of the humidification component or the at least one vaporizer when in an unlocked configuration, and disable operation of the humidification component or the at least one vaporizer when in a locked configuration.
The humidification component and the at least one vaporizer may be configured for cooperation with one another to provide the interlocking mechanism. The humidification component and the at least one vaporizer may be mountable adjacent to one another on the respiratory apparatus. For example, the mount may include a plurality of slots for coupling with the humidification component and the at least one vaporizer in a side-by-side arrangement. The slots may be configured to receive a housing of the humidification component and a housing of the at least one vaporizer. The mount may be configured to receive the housing of the humidification component and the housing of the at least one vaporizer through sliding engagement with the slots.
In some embodiments, the humidification component and the at least one vaporizer may each include a locking element associated with a housing thereof. The locking element may be configured to engage with a corresponding locking element associated with a housing of the other of the humidification component and the at least one vaporizer to provide the interlocking mechanism. The locking element may include at least one locking pin which is retractable within the housing in the locked configuration and extendable from the housing in the unlocked configuration. The locking element may include two or more locking pins, where each locking pin is independently retractable within the housing in the locked configuration and extendable from the housing in the unlocked configuration.
In some embodiments, the humidification component and the at least one vaporizer include a slot associated with a housing thereof, and at least one locking pin is slidably movable between the slots of the humidification component and the at least one vaporizer to provide the interlocking mechanism. The at least one locking pin may be positionable with the slot of the humidification component or the at least one vaporizer in the locked configuration, and may be positionable within the slot of the other of the humidification component or the at least one vaporizer in the unlocked configuration.
In some embodiments, the respiratory apparatus further includes a switching mechanism configured to enable selective operation of the humidification component and the at least one vaporizer. Upon activation of the switching mechanism to operate the humidification component or the at least one vaporizer, the other of the humidification component and the at least one vaporizer may be prevented from operating until the switching mechanism is deactivated.
The switching mechanism may include each of the at least one vaporizer and the humidification component being operable by a switch, and the switches may be linked together to prevent simultaneous operation of the humidification component and the at least one vaporizer.
In some embodiments, the switching mechanism is coupled with the interlocking mechanism. Upon activation of the switching mechanism to operate the humidification component or the at least one vaporizer, the interlocking mechanism may enable operation of the humidification component or the at least one vaporizer and may disable operation of the other of the humidification component or the at least one vaporizer.
In some embodiments, the humidification component includes a humidification chamber through which breathing gases are received and conditioned to the pre-determined temperature and/or humidity. The humidification chamber may be configured to be coupled with the mount. A housing of the humidification chamber may be configured to be slidably received onto the mount. For example, the mount may include a plurality of slots and the housing of the humidification chamber may be slidably receive into one of the slots.
The mount may include a heating element for heating liquid in the humidification chamber. The humidification chamber may include a conductive plate for conducting heat from the heating element in the mount. In other embodiments, the humidification chamber includes a heating element for heating liquid in the humidification chamber. The humidification chamber may be configured to electrically connect with the respiratory apparatus for operation of the humidification chamber.
In some embodiments, the humidification component includes a humidifier having a humidification chamber couplable with a humidification base unit for operation of the humidification chamber. The humidification base unit may be configured to be coupled with the mount. A housing of the humidification base unit may be configured to be slidably received onto the mount. For example, the mount may include a plurality of slots and the housing of the humidification base unit may be slidably receive into one of the slots. The humidification base unit may include a heating element for heating liquid in the humidification chamber.
The humidification chamber as disclosed herein may include an inlet port for receiving a flow of the breathing gases from the respiratory apparatus, and an outlet port for delivering the conditioned flow of breathing gases to the patient. The outlet port may be couplable with an inspiratory conduit for delivering the conditioned flow of breathing gases to the patient via a patient interface.
In other embodiments, the humidification chamber as disclosed herein may include an inlet port for receiving a flow of the breathing gases from the respiratory apparatus, and a return port for returning the conditioned flow of breathing gases to the respiratory apparatus. The return port may be couplable with the respiratory apparatus for returning the conditioned flow of breathing gases.
In some embodiments, the humidification chamber includes a liquid inlet that connects to a liquid reservoir for refilling of the humidification chamber. The humidification chamber may include a flow control mechanism to control flow of liquid into the humidification chamber. The humidification chamber may include at least one sensor for detecting a level of liquid in the humidification chamber. The humidification chamber may include a float valve for controlling a level of liquid in the humidification chamber.
In some embodiments, the humidification component is couplable with the mount via an adapter. The adapter may include a first inlet port for receiving a flow of the breathing gases from the respiratory apparatus, and a first outlet port for delivering the flow of breathing gases to the humidification component. The adapter may further include a second inlet port for receiving a conditioned flow of breathing gases from the humidification component. The adapter may also include a second outlet port for delivering the conditioned flow of breathing gases from the humidification component to the respiratory apparatus.
In some embodiments, the adapter is configured to electrically connect with the respiratory apparatus for operation of the humidification component. The adapter may include a first power connector to provide an electrical connection with the respiratory apparatus. The adapter may also include a second power connector to provide an electrical connection with the humidification component.
The respiratory apparatus may be configured to operate in the following modes of operation: a first mode in which the respiratory apparatus delivers breathing gases to the inspiratory flow path and receives return of expired gases via the expiratory flow path; and a second mode in which the respiratory apparatus delivers breathing gases to the inspiratory flow path at a pre-determined flow rate without return of expired gases from the patient.
In some embodiments, the respiratory apparatus is further configured to detect coupling of the humidification component with the mount to enable operation of the respiratory apparatus in the second mode. For example, the mount may include a sensor for detecting coupling of the humidification component. In the second mode, the humidification component may be operable to condition the flow of breathing gases in the inspiratory flow path to the pre-determined temperature and/or humidity before delivery to the patient.
In some embodiments, the respiratory apparatus further includes a CO2 absorber configured to treat returned expired gas from the patient before recirculating to the patient in the first mode. In the second mode, the CO2 absorber may be further configured to condition the breathing gases in the inspiratory flow path to a pre-determined temperature and/or humidity before delivery to the patient. In the second mode, the CO2 absorber may be configured to condition the breathing gases to the pre-determined temperature and/humidity by one or both of changing an amount of soda lime present in the CO2 absorber, and changing an amount of CO2 provided to the soda lime present in the CO2 absorber.
In the first mode, the respiratory apparatus may be operable to deliver breathing gases to the patient by a first patient interface forming a sealing interface with the patient's airway and returning expired gases to the respiratory apparatus via the expiratory flow path. In the first mode, the breathing gases include one or more anaesthetic agents. The first patient interface may be a mask or endotracheal tube.
In the second mode, the respiratory apparatus may be operable to deliver breathing gases to the patient by a second patient interface forming a non-sealing interface with the patient's airway. The second patient interface may be a nasal cannula.
In the second mode, the pre-determined flow rate may be in a range of about 20 L/min to about 90 L/min.
In the second mode, the pre-determined flow rate may be in a range of about 40 L/min to about 70 L/min.
In some embodiments, the respiratory apparatus is configurable in gas flow communication with a gas delivery apparatus receiving a supply of gas including NO, O2 and air. The gas delivery apparatus may include a gas mixing element for combining one or more of NO, O2 and air in a proportion required for delivering the breathing gases in the first mode and/or the second mode, and a gas outlet supplying gas from the gas delivery apparatus to the respiratory apparatus.
In some embodiments, the respiratory apparatus is configurable in gas flow communication with a flow meter for controlling the flow of gas including one or both of air and O2 in the second mode.
In some embodiments the respiratory apparatus is configurable in gas flow communication with one or more of: a pressure limiting valve configured to maintain substantially stable pressure in the respiratory apparatus in the first mode; a variable volume for displacement of gases in the first mode; a fresh gas flow for replenishing breathing gases delivered to the patient in the first mode; and a vaporizer for vaporizing one or more volatile anaesthetic agents into the flow of the breathing gases before delivery to the patient in the first mode.
In another aspect, the present disclosure provides a humidification component for use with a respiratory apparatus for delivering breathing gases to a patient, the respiratory apparatus including: a flow source for providing a flow of breathing gases in an inspiratory flow path for delivery to the patient; a mount for coupling with at least one vaporizer for vaporizing one or more volatile anaesthetic agents into the flow of breathing gases in the inspiratory flow path before delivery to the patient; and a return path for recirculating expired gases received from the patient via an expiratory flow path to the inspiratory flow path; wherein the humidification component is couplable with the mount for conditioning the flow of breathing gases in the inspiratory flow path to a pre-determined temperature and/or humidity before delivery to the patient.
In some embodiments, operation of the humidification component prevents delivery of the one or more volatile anaesthetic agents into the flow of breathing gases in the inspiratory flow path. Operation of the humidification component may disable operation of the at least one vaporizer.
In some embodiments, the humidification component is couplable with the mount to provide an interlocking mechanism to prevent simultaneous operation of the humidification component and the at least one vaporizer. The interlocking mechanism may be configured to enable operation of the humidification component or the at least one vaporizer when in an unlocked configuration, and disable operation of the humidification component or the at least one vaporizer when in a locked configuration.
The humidification component may be couplable with the mount to enable cooperation with the at least one vaporizer to provide the interlocking mechanism. The humidification component may be mountable on the respiratory apparatus adjacent to the at least one vaporizer. For example, the mount may include a plurality of slots for coupling with the humidification component and the at least one vaporizer in a side-by-side arrangement. The slots may be configured to receive a housing of the humidification component and a housing of the at least one vaporizer. The mount may be configured to receive the housing of the humidification component and the housing of the at least one vaporizer through sliding engagement with the slots.
In some embodiments, the humidification component includes a housing having a locking element configured to engage with a corresponding locking element associated with a housing of the at least one vaporizer to provide the interlocking mechanism. The locking element may include at least one locking pin which is retractable within the housing in the locked configuration and extendable from the housing in the unlocked configuration. The locking element may include two or more locking pins, where each locking pin is independently retractable within the housing in the locked configuration and extendable from the housing in the unlocked configuration.
In some embodiments, the humidification component includes a housing having a slot, and at least one locking pin is slidably movable between the slot of the humidification component and a slot associated with a housing of the at least one vaporizer to provide the interlocking mechanism. The at least one locking pin may be positionable within the slot of the humidification component in the locked configuration and may be positionable within the slot of the at least one vaporizer in the unlocked configuration.
In some embodiments, the respiratory apparatus further includes a switching mechanism configured to enable selective operation of the humidification component and the at least one vaporizer. Upon activation of the switching mechanism to operate the humidification component, the at least one vaporizer may be prevented from operating until the switching mechanism is deactivated.
The switching mechanism may include the humidification component being operable by a switch, and the switch may be linked together with a switch of the at least one vaporizer to prevent simultaneous operation of the humidification component and the at least one vaporizer.
The humidification component may further include a switch operable by a user to enable selective operation of the humidifier. For example, the switch may be a manually operated switch, such as a button or dial, on a housing of the humidification component.
In some embodiments, the switching mechanism is coupled with the interlocking mechanism. Upon activation of the switching mechanism to operate the humidification component, the interlocking mechanism may enable operation of the humidification component and disable operation of the at least one vaporizer.
In some embodiments, the humidification component includes a humidification chamber through which breathing gases are received and conditioned to the pre-determined temperature and/or humidity. The humidification chamber may be configured to be coupled with the mount. A housing of the humidification chamber may be configured to be slidably received onto the mount. For example, the mount may include a plurality of slots and the housing of the humidification chamber may be slidably received into one of the slots.
The mount may include a heating element for heating liquid in the humidification chamber. The humidification chamber may include a conductive plate for conducting heat from the heating element in the mount. In other embodiments, the humidification chamber includes a heating element for heating liquid in the humidification chamber. The humidification chamber may be configured to electrically connect with the respiratory apparatus for operation of the humidification chamber.
In some embodiments, the humidification component includes a humidifier having a humidification chamber couplable with a humidification base unit for operation of the humidification chamber. The humidification base unit may be configured to be coupled with the mount. A housing of the humidification base unit may be configured to be slidably received onto the mount. For example, the mount may include a plurality of slots and the housing of the humidification base unit may be slidably received into one of the slots. The humidification base unit may include a heating element for heating liquid in the humidification chamber.
The humidification chamber as disclosed herein may include an inlet port for receiving a flow of the breathing gases from the respiratory apparatus, and an outlet port for delivering the conditioned flow of breathing gases to the patient. The outlet port may be couplable with an inspiratory conduit for delivering the conditioned flow of breathing gases to the patient via a patient interface.
In other embodiments, the humidification chamber as disclosed herein may include an inlet port for receiving a flow of the breathing gases from the respiratory apparatus, and a return port for returning the conditioned flow of breathing gases to the respiratory apparatus. The return port may be couplable with the respiratory apparatus for returning the conditioned flow of breathing gases.
In some embodiments, the humidification chamber includes a liquid inlet that connects to a liquid reservoir for refilling of the humidification chamber. The humidification chamber may include a flow control mechanism to control flow of liquid into the humidification chamber. The humidification chamber may include at least one sensor for detecting a level of liquid in the humidification chamber. The humidification chamber may include a float valve for controlling a level of liquid in the humidification chamber.
In some embodiments, the humidification component is couplable with the mount via an adapter. The adapter may include a first inlet port for receiving a flow of the breathing gases from the respiratory apparatus, and a first outlet port for delivering the flow of breathing gases to the humidification component. The adapter may further include a second inlet port for receiving a conditioned flow of breathing gases from the humidification component. The adapter may also include a second outlet port for delivering the conditioned flow of breathing gases from the humidification component to the patient or to the respiratory apparatus.
The respiratory apparatus may be configured to operate in the following modes of operation: a first mode in which the respiratory apparatus delivers breathing gases to the inspiratory flow path and receives return of expired gases via the expiratory flow path; and a second mode in which the respiratory apparatus delivers breathing gases to the inspiratory flow path at a pre-determined flow rate without return of expired gases from the patient.
In some embodiments, the respiratory apparatus is further configured to detect coupling of the humidification component with the mount to enable operation of the respiratory apparatus in the second mode. For example, the mount may include a sensor for detecting coupling of the humidification component. In the second mode, the humidification component may be operable to condition the flow of breathing gases in the inspiratory flow path to the pre-determined temperature and/or humidity before delivery to the patient.
In some embodiments, the respiratory apparatus further includes a CO2 absorber configured to treat returned expired gas from the patient before recirculating to the patient in the first mode. In the second mode, the CO2 absorber may be further configured to condition the breathing gases in the inspiratory flow path to a pre-determined temperature and/or humidity before delivery to the patient. The respiratory apparatus may be further configured to enable the CO2 absorber in the second mode to condition the breathing gases to the pre-determined temperature and/humidity by one or both of changing an amount of soda lime present in the CO2 absorber, and changing an amount of CO2 provided to the soda lime present in the CO2 absorber.
In the first mode, the respiratory apparatus may be operable to deliver breathing gases to the patient by a first patient interface forming a sealing interface with the patient's airway and returning expired gases to the respiratory apparatus via the expiratory flow path. In the first mode, the breathing gases include one or more anaesthetic agents. The first patient interface may be a mask or endotracheal tube.
In the second mode, the respiratory apparatus may be operable to deliver breathing gases to the patient by a second patient interface forming a non-sealing interface with the patient's airway. The second patient interface may be a nasal cannula.
In the second mode, the pre-determined flow rate may be in a range of about 20 L/min to about 90 L/min.
In the second mode, the pre-determined flow rate may be in a range of about 40 L/min to about 70 L/min.
In some embodiments, the respiratory apparatus is configurable in gas flow communication with a gas delivery apparatus receiving a supply of gas including NO, O2 and air. The gas delivery apparatus may include a gas mixing element for combining one or more of NO, O2 and air in a proportion required for delivering the breathing gases in the first mode and/or the second mode, and a gas outlet supplying gas from the gas delivery apparatus to the respiratory apparatus.
In some embodiments, the respiratory apparatus is configurable in gas flow communication with a flow meter for controlling the flow of gas including one or both of air and O2 in the second mode.
In some embodiments the respiratory apparatus is configurable in gas flow communication with one or more of: a pressure limiting valve configured to maintain substantially stable pressure in the respiratory apparatus in the first mode; a variable volume for displacement of gases in the first mode; a fresh gas flow for replenishing breathing gases delivered to the patient in the first mode; and a vaporizer for vaporizing one or more volatile anaesthetic agents into the flow of the breathing gases before delivery to the patient in the first mode.
The invention will now be described in greater detail with reference to the accompanying drawings in which like features are represented by like numerals. It is to be understood that the embodiments shown are examples only and are not to be taken as limiting the scope of the invention as defined in the claims appended hereto.
Embodiments of the invention are discussed herein by reference to the drawings which are not to scale and are intended merely to assist with explanation of the invention.
A breathing circuit delivers gases to the patient 300 and returns expired gases to rebreathing components 140. Typically the breathing circuit includes corrugated tubing, valves and one or more patient interfaces for directing gases into the patient's airway and removing expired gases. In the schematic illustration of
One or more vaporizers 150 convert volatile anaesthetics such as isoflurane and sevoflurane from liquid to vapour, and control introduction of these agents into the breathing circuit in accurately controlled concentration and dosages as required by the user, typically an anaesthetist clinician. Typically, vaporizers 150 are manually controlled but may be precision controlled by a controller of the respiratory apparatus. In some embodiments, vaporizers 150 feed into the rebreathing components 140.
Integrated into the anaesthesia machine 10 is a ventilation system which ventilates patient 300 during induction and after administration of anaesthetic agents to achieve ongoing anaesthesia. A manual ventilation bag 142 is typically used during induction (dot-dash lines inside rebreathing components 140) when volatiles are being delivered and prior to the patient being intubated. The compliance of the ventilation bag 142 enables the patient to breathe in and out a fixed volume of gas through a sealing first patient interface 120 in the form of a face mask. Once intubated, the ventilation mode changes from manual to mechanical, effectively isolating the manual ventilation bag 142 and associated pressure relief valve 143 from the rebreathing components 140 so that ventilation occurs via a mechanical system (dash lines inside rebreathing components 140). Typically this involves a collapsible bellows 145 that controls the tidal volume and timing of breaths delivered to the patient through a sealing first patient interface 120 in the form of an endotracheal tube. Gases provided to the patient may be pressure, flow or volume controlled. Pressure relief valves 143, 146 provide for release of excess gases from the rebreathing components 140 (arising from fresh gas flow from vaporizers 150 and returned expired patient gases) while preventing ambient air from entering the breathing circuit.
Rebreathing components 140 provide a gas recirculation system in which exhaled gases from the patient are treated as they flow around the circuit and are then re-inhaled. This provides advantages by reusing oxygen and volatiles that are present in the expired gas flow from the patient, reducing costs as well as the presence of anaesthetic agents in the atmosphere. Expired gases in the rebreathing components 140 are passed through CO2 absorber 141 which may include a canister containing soda lime (or another CO2 absorbing substance). The soda lime (a mixture of NaOH & Ca(OH)2) acts as a CO2 scrubber to remove CO2 before gases in the rebreathing components 140 re-enter the inspiratory conduit 110. Additionally, gases from pressure relief valves 143, 146 are directed via an exhaust (not shown) to an external scavenger system 144 which filters and collects anaesthetic gases from the gas flow.
It is to be understood that further features may be provided as part of an anaesthesia machine 10, such as e.g. patient monitoring, suction, pressure gauges, regulators and “pop-off” valves to protect the patient and components of the machine from high pressure gases, as are known in the art. For simplicity, these are not included in the example shown.
In this specification, “high flow” means, without limitation, any gas flow with a flow rate that is higher than usual/normal, such as higher than the normal inspiration flow rate of a healthy patient, or higher than some other threshold flow rate that is relevant to the context. It can be provided by a non-sealing respiratory system with substantial leak, for example happening at the entrance of the patient's airways. It can also be provided with humidification to improve patient comfort, compliance and safety. “High flow” can mean any gas flow with a flow rate higher than some other threshold flow rate that is relevant to the context—for example, where providing a gas flow to a patient at a flow rate to meet inspiratory demand, that flow rate might be deemed “high flow” as it is higher than a nominal flow rate that might have otherwise been provided. “High flow” is therefore context dependent, and what constitutes “high flow” depends on many factors such as the health state of the patient, type of procedure/therapy/support being provided, the nature of the patient (big, small, adult child) and the like. A person skilled in the art would appreciate, in a particular context what constitutes “high flow”. But, without limitation, some indicative values of high flow can be as follows.
In some configurations, high flow delivery of gases to a patient at a flow rate of greater than or equal to about 5 or 10 litres per minute (5 or 10 LPM or L/min).
In some configurations, high flow delivery of gases to a patient is at a flow rate of about 5 or 10 LPM to about 150 LPM, or about 10 LPM to about 120 LPM, or about 15 LPM to about 95 LPM, or about 20 LPM to about 90 LPM, or about 20 LPM to about 70 LPM, or about 25 LPM to about 85 LPM, or about 30 LPM to about 80 LPM, or about 35 LPM to about 75 LPM, or about 40 LPM to about 70 LPM, or about 45 LPM to about 65 LPM, or about 50 LPM to about 60 LPM. For example, according to those various embodiments and configurations described herein, a flow rate of gases supplied by embodiments of the systems disclosed, may comprise, but is not limited to, flows of at least about 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150 LPM, or more, and useful ranges may be selected to be any of these values (for example, about 20 LPM to about 90 LPM, about 15 LPM to about 70 LPM, about 20 LPM to about 70 LPM, about 40 LPM to about 70 LPM, about 40 LPM to about 80 LPM, about 50 LPM to about 80 LPM, about 60 LPM to about 80 LPM, about 70 LPM to about 100 LPM, about 70 LPM to about 80 LPM). Thus, ‘high flow’ or ‘high flow respiratory support may refer to the delivery of gases to a patient at a flow rate of between about 5 or 10 LPM and about 100 LPM, or between about 15 LPM and about 95 LPM, or between about 20 LPM and about 90 LPM, or between about 25 LPM and about 85 LPM, or between about 30 LPM and about 80 LPM, or between about 35 LPM and about 75 LPM, or between about 40 LPM and about 70 LPM, or between about 45 LPM and about 65 LPM, or between about 50 LPM and about 60 LPM.
In “high flow” the gas delivered will be chosen depending on for example the intended use of a therapy or support. Gases delivered may comprise a percentage of oxygen. In some configurations, the percentage of oxygen in the gases delivered may be about 15% to about 100%, 20% to about 100%, or about 30% to about 100%, or about 40% to about 100%, or about 50% to about 100%, or about 60% to about 100%, or about 70% to about 100%, or about 80% to about 100%, or about 90% to about 100%, or about 100%, or 100%.
Flow rates for “High flow” for premature/infants/paediatrics (with body mass in the range of about 1 to about 30 kg) can be different. The flow rate can be set to about 0.4 LPM/kg to about 8 LPM/kg with a minimum of about 0.5 LPM and a maximum of about 70 LPM. For patients under 2 kg maximum flow may be set to 8 LPM.
High flow may be used as a means to promote gas exchange and/or respiratory support through the delivery of oxygen and/or other gases, and through the removal of CO2 from the patient's airways. High flow may be particularly useful prior to, during or after a medical procedure. Further advantages of high gas flow can include that the high gas flow increases pressure in the airways of the patient, thereby providing patency support that opens airways, the trachea, lungs/alveolar and bronchioles. The opening of these structures enhances oxygenation, and to some extent assists in removal of CO2.
The increased pressure can also keep structures such as the larynx from blocking the view of the vocal chords during intubation. When humidified, the high gas flow can also prevent airways from drying out, mitigating mucociliary damage, and reducing risk of laryngospasms and risks associated with airway drying such as nose bleeding, aspiration (as a result of nose bleeding), and airway obstruction, swelling and bleeding.
In this specification, the terms subject and patient are used interchangeably. A subject or patient may refer to a human or an animal subject or patient.
In this specification, it is intended that reference to a range of numbers disclosed herein (for example, 1 to 10) also incorporates reference to all rational numbers within that range (for example, 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example, 2 to 8, 1.5 to 5.5 and 3.1 to 4.7) and, therefore, all sub-ranges of all ranges expressly disclosed herein are hereby expressly disclosed. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner.
Embodiments of the present disclosure provide systems and apparatus that provide for integration of different forms of respiratory support into a single system, or provide integrated switching between separate systems or apparatuses that enables convenient use of those systems or apparatuses by a clinician user who may desire to switch between different forms of respiratory support delivered to a patient. Aspects of the disclosure relate to various systems, devices, apparatuses, switching mechanisms and lumen assemblies as well as systems incorporating humidification. It is to be understood that one of skill in the art would appreciate that various features and advantages described in the context of one aspect have utility in the context of another aspect and that such combinations are within the scope of and expressly form part of this disclosure.
System Switching with Gas Control
A switching means 700 is operable to select a mode of operation of the system 1000, said mode of operation being selected from a group including a first mode in which breathing gases are delivered to the patient by the first respiratory apparatus 100 and a second mode in which breathing gases are delivered to the patient by the second respiratory apparatus 200 at the predetermined flow rate which is typically in a range of about 20 LPM to about 90 LPM for most patients.
A switching mechanism may in turn consist of or include one or more switching elements. Thus the switching means 700 may include a user operable actuator which enables a user to manually select the mode of operation and in turn, causes operation of system components in the selected mode, and/or a sensor driven automated system that operates the system components in a mode which is determined by a sensor detecting e.g. which of the first patient interface 100 and the second patient interface 200, is coupled with the patient's airway 310. Various switching elements may be operatively coupled to actuate substantially simultaneously, or in response to other switching elements or actuators or under control of a controller as will become apparent by reference to the non-limiting examples provided.
While various embodiments are disclosed herein that prevent delivery of anaesthetic agents to the patient when the second mode is selected, it is to be understood that yet other approaches may be deployed, as alternatives or in addition to the examples shown in the Figures. For example, the system 1000 may inactivate release of anaesthetic agents to the patient by shutting down vaporizers or reducing their function to a level that is ineffective. Alternatively or additionally the system 1000 may inactivate delivery of anaesthetic agents to the first respiratory apparatus 100. Alternatively or additionally the system may inactivate anaesthetic agents in a flow of breathing gases delivered from the first respiratory apparatus 100 by use of a neutralizer in the first respiratory apparatus that becomes activated when the system is operated in the second mode such that any anaesthetic agents that may be flowing through the system are rendered ineffective. While wasteful this can be an important safety measure.
When the first mode is selected, the system 1000 directs breathing gases in a first inspiratory flow path 110, in which a first patient interface 120 directs breathing gases into an airway 310 of the patient 300. The first patient interface 120 is a sealing interface such as a sealing mask or endotracheal tube and is configured to direct expired gases from the patient to an expiratory flow path 130 which returns the expired gases to the first respiratory apparatus 100. Returned expired gases are treated by rebreathing components 140 as described in relation to
When the second mode is selected, the system 1000 isolates flow of breathing gases from the first respiratory apparatus 100 so as to prevent delivery of anaesthetic gas including NO and vaporized anaesthetic agents to the patient 300. Thus when the second mode is selected, the system directs flow of breathing gases in a second inspiratory flow path 210 in which a second patient interface 220 directs the breathing gases into an airway 310 of the patient 300 and is a non-sealing interface. Typically, the second patient interface is a nasal cannula having one or more nasal prongs directing gases into one or both nares of the patient.
In one embodiment, the switching means 700 includes a switching mechanism located between a gases supply 1060 and the first and second respiratory apparatuses 100, 200 and includes a gas delivery apparatus which receives a supply of gases including NO, O2 and/or air and provides a flow meter to control the flow rate of gases through one or more breathing gas outlets. Preferably, the flow meter controls flow of breathing gases through the one or more breathing gas outlets responsive to selection of the first mode of operation or the second mode of operation. This may be brought into effect in several ways.
In one example shown schematically in
Flow meter 1090 controls flow rate of breathing gas from the gas mixing element 1042. First gas outlet 1044A supplies breathing gas from the gas delivery apparatus 1040 to the first respiratory apparatus 100 when the first mode is selected (
In another example shown schematically in
In
In the embodiments shown in
In some embodiments, the unitary machine may include a humidifier (not shown), typically located between the flow meter and the second patient interface 220 delivering gases from the second respiratory apparatus 200. The humidifier is configured to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode. This has the advantage of streamlining set-up of the humidifier by integrating it into the daily routine of setting up the integrated system 1000.
However, it is to be understood that the switching mechanism described could similarly be deployed in a system 1000 in which the first respiratory apparatus 100 and second respiratory apparatus 200 are separate machines. Beneficially, the switching means 700 as described provides integrated control of the operation of these machines such that a single switching input simultaneously permits delivery of gas to the patient from the first respiratory apparatus 100 and prevents delivery of gas from the second respiratory apparatus 200 when the first mode is selected, or the vice versa when the second mode is selected.
Advantageously, the embodiments shown in
In another example shown schematically in
In the second mode of operation, depicted in
Switching System with Manifold
In another example of a system 1000 in which the switching mechanism 700 is located between gas source 1060 and the first and second respiratory apparatuses 100, 200, a gas diverter receiving a supply of gases including anaesthetic gas and a breathing gas contains two switching means operable to control flow of gases to the first and second respiratory apparatuses. An example of a gas diverter 800 is depicted schematically in
In the first mode depicted in
Advantageously, the gas diverter manifold 800 is installed between a gas supply 1060, such as a gas wall supply in an operating theatre (or other medical location) and the gas inlet ports of the first respiratory apparatus 100 which are in fluid communication with vaporizer 150 (see
While the gas diverter 800 has been described in the context of a component of the system 1000, it is to be understood that gas diverter 800 may be supplied as a standalone device for use with a respiratory system such as a system providing the functionality of the first respiratory apparatus 100 (typically an anaesthesia machine) and the second respiratory apparatus 200 (delivering high flow respiratory support). Although the gas diverter 800 depicted in
As disclosed in the context of
In some embodiments, gas delivery device 800 is operable in a third configuration in which both the first flow path and the second flow path are open and a stop-cock or other blocking mechanism may be utilised at the patient end to preclude flow though the first or second patient interface. A gas mixer (not shown) may also be included for combining received gases in a proportion required to deliver a required therapy. The gas delivery device 800 may include a switching means operable by a user to select a configuration for operation of the gas delivery device which is achieved by switching elements (e.g. valves and gas flow diverters) in the manifold. The switching means may be located e.g. on the gas diverter device 800, the first respiratory apparatus 100 or on the second respiratory apparatus 200, or on a patient interface through which breathing gas is directed into an airway of the patient.
The switching means may be pneumatic, mechanical, electronic or utilise any other mechanism that is suitable to trigger operation of the switching elements. In an embodiment utilising electronic switching means, gas delivery device 800 is configured for connection to a power source and the power source may include a battery. Ideally both mains power and battery supplies are utilised, such that in the event of power outage, the battery is charged and ensures continued operation of the gas delivery device until conclusion of the procedure or until mains power is restored.
In some embodiments, the switching means is activated in response to detection of a change in state detected by one or more system sensors. These sensors may include one or more of e.g. a pressure sensor, CO2 sensor, O2 sensor, flow sensor, gas concentration sensor or the like and they are ideally located and configured to determine if a breathing circuit delivering gases to the patient airway is associated with a first patient interface by which gases (e.g. including anaesthetic agents) are delivered to the patient airway by a substantially sealed interface, or associated with a second patient interface by which gases excluding anaesthetic agents are delivered to the patient in by a non-sealing interface. The switching means may be in wired or wireless communication with one or more switching elements to control operation of the gas delivery device according to the configuration selected by the user.
In some embodiments, gas delivery device includes an output module (akin to monitor 1094 in
O2 switching
In another example of a system 1000 in which the switching mechanism 700 is located between a gas source 1060 and the first and second respiratory apparatuses 100, 200, the switching mechanism includes a first switching element 710 operable to direct flow of O2 to the first respiratory apparatus 100 in the first mode and to the second respiratory apparatus 200 in the second mode.
As in the embodiments exemplified in
The embodiments shown in
In some embodiments, including in the context of the examples already described, it may be desirable that the predetermined flow rate of breathing gas delivered to the patient 300 in the second mode is selectable from a range of from about 20 LPM to about 90 LPM by the user operating the switching means although in some cases such as paediatric or neonatal patients, a lower range may be desired. Preferably, the required pre-determined flow rate is selectable by the user from a plurality of pre-determined available flow rates such as e.g. 0 LPM, 40 LPM and 70 LPM although it is to be understood that additional and/or different predetermined rates may be selectable within the high flow ranges disclosed herein.
Selection of the required predetermined rate may be achieved by operation of the switching means 700 which in some embodiments includes a rate selector in the form of e.g. a knob, sliding switch, touch screen or other actuator which provides for user selection of the required predetermined flow rate from a plurality of predetermined flow rates. An example of a rate switching element 730 associated with a rate selector is presented in the schematic illustration of
In some embodiments operation of the rate switching element 730 to select a rate of 0 LPM permits supply of O2 to the first respiratory apparatus. This is shown schematically in
In another example involving a rate selector, a pressure controlled actuator is deployed to control of flow to the first and second respiratory apparatuses 100, 200 as shown in the schematic illustration of
In some embodiments, switching means 700 provides yet further functionality for system 1000 in that it can provide for selection by the user of a manual first mode of operation or a mechanical first mode of operation of the first respiratory apparatus, as well as operation of the system in the second mode. In the manual first mode of operation the first respiratory apparatus 100 deploys a ventilation bag for manual ventilation of the patient 300 e.g. during intubation, with a medical professional manually squeezing the bag to control the timing and tidal volume of the breathing gases delivered to the patient's airway by the first patient interface. In the mechanical first mode of operation the first respiratory apparatus 100 deploys the bellows to provide for mechanical ventilation of the patient 300, e.g. once sedated, wherein the bellows control the tidal volume and timing of inhalations/exhalations. In both cases, a pressure relief valve is provided to avoid over pressure in the system in the breathing circuit connected to the patient's airway.
In one embodiment, the additional functionality which provides for selection of the manual first mode of operation, the mechanical first mode of operation or the second mode of operation of system 1000 is achieved by inclusion of a 3-way actuator. On example is provided in the schematic illustration of
It is to be understood that while the embodiment shown in
An electronically enabled switch may be physically attachable to one or both of the first or second patient interfaces 120, 220 to enable quick switching of the system's mode of operation when the patient interface is swapped, e.g. when moving from pre-intubation to intubation, or when weaning the patient from sedation. Thus, a button or electronic switch located on the patient interface can be activated, causing system 1000 to select the mode of operation that will safely deliver gases to the patient through that interface. Alternatively a foot pedal or foot-operated switch or voice control may be utilised. Each of these has the potential to improve accessibility of mode selection while the anaesthetist is away from the controls located on the anaesthetic machine.
Machine Detected Changes Cause Switching on/Off NHF
While some embodiments of the system provide mechanical, pneumatic, or other physical control and operational coupling of switching elements, in some embodiments system 1000 includes a controller 1010 receiving inputs from one or more sensors deployed throughout the system. The sensors detect if a breathing circuit coupled with the patient's airway is associated with the first patient interface 120 for use with first respiratory apparatus 100 or the second patient interface 220 for use with the second respiratory apparatus 200. This information is used by the controller 1010 to operate the switching means 700 to select the mode of operation. Thus, when the sensor/s detect that the breathing circuit associated with the first patient interface 120 then the controller 1010 ensures the system is operating in the first mode of operation. Conversely, when the sensor/s detect that the breathing circuit associated with the second patient interface 220 then the controller 1010 ensures the system is operating in the second mode of operation delivering Nasal High Flow (NHF) respiratory support.
The sensors may include a pressure sensor arranged to measure back pressure in one or both of the first respiratory apparatus 100 and second respiratory apparatus 200. The system 1000 may provide a continual or intermittent flow of breathing gases through the first respiratory apparatus 100 and/or second respiratory apparatus to enable a measurement of the back pressure in the first respiratory apparatus 100 and/or second respiratory apparatus. In some embodiments, this continual or intermittent flow of breathing gases comprises a flow rate, pressure and/or volume less than the flow of breathing gases provided to the patient in the first and/or second mode. Different resistance to flow values are associated with each of the first (sealing) patient interface 120 and second (non-sealing) patient interface when coupled to the patient 300 which are used in the first and second modes respectively. When the measured back pressure indicates breathing gas is delivered to the patient by a sealing patient interface that is substantially sealed with the patient, the controller 1010 determines the breathing circuit to be associated with the first patient interface and operates the system 1000 in the first mode in which breathing gases and anaesthetic agents are deliverable to the patient 300, and expired gases returned to the rebreathing components. Alternatively, when the measured back pressure indicates breathing gas is delivered to the patient by a non-sealing patient interface, the controller 1010 determines the breathing circuit to be associated with the second respiratory apparatus and operates the system 1000 in the second mode in which breathing gases excluding anaesthetic agents are delivered to the patient at the predetermined (high flow) flow rate. In some embodiments, the pressure sensor may be located at or downstream of a flow modulator 250 of the system although the pressure sensor may be located at any convenient location in the gas flow pathway between the patient airway and the flow modulator 250.
Alternatively/additionally, the one or more sensors may include a CO2 sensor associated with a first breathing circuit associated with the first patient interface 120 and/or a second breathing circuit associated with the second patient interface 220. In such embodiments, the controller 1010 determines the breathing circuit in which expired gas from the patient contains a higher concentration of CO2 than ambient air to be the breathing circuit that is coupled with the patient's airway. If CO2 concentration in both breathing circuits is higher than ambient air, the controller determines the breathing circuit with the higher CO2 concentration to be the breathing circuit that is coupled with the patient's airway.
Alternatively/additionally, the sensors may include one or more proximity sensors such as e.g. acoustic (including audible and/or ultrasonic), optical (including infra-red), radiofrequency, pressure (in the inspiratory/expiratory conduits and/or mask cuff), flow, electrical conductivity, resistance, temperature or other sensors to determine which of the breathing circuit is coupled with the patient's airway by the first or the second patient interface. Such proximity sensors are explained in further detail in WO2016/157105A1, the contents of which are hereby incorporated herein by reference.
The switching means 700 may include one more actuators that are operable by a user, such as, but not limited to one or more of a button, switch, knob, foot operated switch or pedal. Alternatively/additionally switching means 700 may include one or more of an electronic input device, touch screen, voice activated sensor or the like, as may be operable in concert with an electronic controller of the system as will be described. One or more actuators of the switching means may be located at or near a first or second patient interface 120, 220 through which breathing gas is delivered to the patient by the first respiratory apparatus 100 or the second respiratory apparatus 100. Locating one or more of the actuators at or near the patient end of a breathing circuit delivering gases to the patient's airway provides convenience for a clinician working on the patient throughout phases of anaesthesia where it is often necessary to switch between modes of operation of the system and the form of breathing support that is delivered. Locating an actuator enabling mode selection at the patient end may be more convenient and time saving for the clinician and others in their vicinity. In other arrangements, the system 1000 is configurable to detect which of the first or second patient interfaces is attached to the patient, and modify the mode of operation accordingly.
It is to be understood that the switching means 700 may include one or more switching mechanisms such as mechanical, electronic, electromechanical, electromagnetic, pneumatic or any other suitable switching mechanisms to achieve the functionality disclosed herein. Furthermore, the one or more switching mechanisms are couplable with the switching means via wired and/or wireless coupling using techniques readily understood and ascertainable by one of skill in the art. Switching mechanisms may include actuators operable by a user of the system 1000 to select the required mode of operation and may include or consist of any of the switching mechanisms described. In some embodiments, an actuator includes an electronic input device in wireless communication with a controller 1010 of the system 1000 and movably locatable to different positions with respect to the patient 300 and/or the first and second breathing apparatuses 100, 200.
In some embodiments, the one or more switching mechanisms are operable to control one or more characteristics of breathing gases delivered to the subject, such as but not limited to presence of volatiles, flow rate, gas composition, gas concentration, temperature, and/or humidity.
For conciseness, certain features of the first respiratory apparatus 100 are not always shown in the figures. However it is to be understood that in preferred embodiments the first respiratory apparatus 100 performs the function of an anaesthetic machine 10 and includes one or more of a CO2 absorber 141 configured to treat returned expired gas before recirculating to the patient in the first mode, a pressure limiting valve 146 configured to maintain substantially stable pressure in the system in the first mode, a variable volume 145 for displacement of gases in the first mode (e.g. using bellows or a bag ventilator), a fresh gas flow for replenishing anaesthetic gas delivered to the patient in the first mode and a vaporizer 150 for vaporizing volatile anaesthetic agents into breathing gas delivered to the patient in the first mode.
Similarly, for conciseness certain features of the second respiratory apparatus 200 are not always shown in the figures. However it is to be understood that in preferred embodiments the second respiratory apparatus 200 delivers high flow respiratory support as described herein, and includes one or more of a flow source 250 or modulator configured to generate gas flows through the system. A humidifier 420 configured to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode is also typically provided although in some cases it may be omitted.
Anaesthesia machine with 3 Modes Including O2 Flush
The respiratory apparatus includes switching means operable to select one of the modes of operation from the plurality of modes. The switching means may include one or more actuators such as a button, switch, knob, foot operated switch or pedal, denoted in
In the second mode, the respiratory apparatus is operable to deliver breathing gases to the patient by a second patient interface, such as a nasal cannula, which forms a non-sealing interface with the patient's airway. Notably, in the first mode, FGF containing anesthetic agents from the NO source and/or vaporizer 150 enter the inspiratory gas flow path to supplement the patient's sedation. However, in the second and transient modes, flow of FGF to the second patient interface is disabled by switching element 720 preventing release of an aesthetic agents into the environment via the non-sealing interface, avoiding inhalation of these agents by carers attending to the patient, while also reducing wastage. In some configurations, the inspiratory flow path in the second and transient modes are the same. In some configurations, the inspiratory flow path in the first and third modes are the same.
In a preferred embodiment, the transient mode is activated only during operation of an actuator that is normally biased off. For example, the switching means may include a button or trigger configured to be activated by a user to operate the respiratory apparatus in the transient mode while the trigger or button is depressed and wherein release of the button or trigger disables the transient mode. Operation of the button or trigger may open flush valve 730 which permits high flows of O2 to flow through the system, bypassing the gas mixing element 1042 and flow meter 1090. The transient mode may be used to flush the respiratory apparatus with O2 e.g. during setup or after use. Ideally, the user can select the transient mode to flush the respiratory apparatus including the first and or second respiratory apparatuses. This may include flushing the first respiratory apparatus 100 in a manual mode of operation in which bag ventilation components are flushed, or in a mechanical mode of operation in which mechanical bellows system components are flushed. This may require manual connection of the ventilation bag for some machines although typically this is always connected with manual (bag) or mechanical (bellows) ventilation mode being selectable by a user operating a switch that alters the gas flow path to the selected ventilation components.
For operation of the respiratory apparatus in the second mode, it is desirable to configure the apparatus in gas flow communication with a flow modulator configured to provide gas flows through the system at a predetermined flow rate consistent with high flow respiratory support, and a humidifier configured to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode. Such features are represented in
Blower Driven Anaesthesia Machine with High Flow Mode
Another aspect of the present disclosure provides a system for delivering breathing gases to a patient which enables delivery of different modes of respiratory support including ventilation, anaesthesia and in some embodiments, high flow respiratory support.
Ideally, the flow generator 1350 is a blower with variable control which is selectable by a user or a system controller. Ideally the switching actuator includes or is operatively coupled with a switching mechanism 1370 which controls flow of fresh gas into system 1300 according to the mode of operation selected using the switching actuator. In the first mode (
Typically, the switching mechanism 1370 is located upstream of the flow generator 1350 as shown in
In some embodiments, operation of system 1300 in the first mode enables delivery of anaesthesia. In such embodiments, system 1300 also receives a supply of oxygen from O2 source 1060 and vaporized volatile anaesthetic agents such as sevoflurane from vaporizer 150. These gases are mixed in the required proportions and concentrations (as determined by a user or a controller of the system) by gas mixer 1042. The mixed gases are delivered to the patient via inspiratory conduit 110 and sealing first patient interface 120 into the patient's airway 310. Expired gases are returned by the first patient interface 120 to the expiratory conduit 130 and to the system 1300, where CO2 is removed by CO2 absorber 141 and the gases are recycled back to the inspiratory pathway.
In some embodiments, operation of system 1300 in the second mode enables provision of ventilatory support to the patient. This form of support can be delivered by the same first patient interface 120 as in the first mode of operation with the distinction that the switching mechanism 1370 operates to permit flow of fresh air into the system 1300 while preventing recirculation of gases. Thus, gases returned by expiratory conduit 130 may be vented to the environment or an exhaust, or released through vent holes in a patient interface through which respiratory support is delivered. In another form of respiratory support delivered in the second mode, the first patient interface 120 is replaced with a non-sealing patient interface such as a nasal cannula, and the flow rate generated by flow generator is increased to deliver high flows, so that the system 1300 is operated in a second mode delivering high flow respiratory support to the patient 300. Thus, operation of the switching actuator to select the second mode causes operation of the flow generator at a flow rate (e.g. up to 90 LPM) sufficient to deliver high flow respiratory support. In embodiments where switching actuator 1370 is a pressure controlled gas flow diverter, a low back pressure in the system 1300 consistent with connection of second, non-sealing patient interface 220 such as nasal cannula (or disconnection of the expiratory conduit 130 from the system 1300) automatically opens flow of fresh gas into the system while shutting off recirculation of gases. O2 may also be provided from O2 source 1060 during operation of the system in the second mode, with the O2 concentration selected by operation of the switching actuator which may be operatively coupled with the O2 source or gas mixer 1042, or by manual selection of O2 concentration at a supply controller provided at the O2 source. System 1300 is also configured to prevent supply of anaesthesia gases to the system when the second mode is selected. This may be achieved by providing shutting off vaporizer 150 either manually by the user, or by providing a vaporizer switching mechanism that is operatively linked with the switching mechanism 1370 and/or system controller 1010.
In some embodiments, system 1300 includes a pressure relief valve 146 to maintain substantially stable gas pressure in the system when operating in the first mode, which would otherwise increase with addition of oxygen and volatiles to system 1300 in the first mode. An exhalation valve 143 or variable flow constriction may be provided to modulate gas flows in the system 1300 to generate expiratory and inspiratory breathing cycles, particularly when this cannot be achieved by modulating flow through of flow generator 1350. As shown in
In various embodiments, system 1300 includes a humidifier configured to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode. Ideally, the humidifier (not shown) is located downstream of the blower, before the second patient interface 220.
Another system for delivering breathing gases to a patient which enables delivery of different modes of respiratory support including ventilation, anaesthesia and in some embodiments, high flow respiratory support is shown in the schematic illustration of
In some embodiments, during the first mode of operation of system 1300, gases delivered to the patient 300 in the recirculating gases flow include an anaesthetic agent delivered by vaporizer 150 which vaporizes volatile anaesthetic agents into breathing gas delivered to the patient. Thus, the first set of respiratory components of the first module 1380 may include one or more of: a CO2 absorber 141 configured to treat returned expired gas before recirculating to the patient in the first mode; a pressure limiting valve 146 configured to maintain substantially stable pressure in the system in the first mode; a variable volume (such as a ventilation bag 142 or bellows) for displacement of gases in the first mode. A fresh gas flow from vaporizer 150 replenishes anaesthetic gas delivered to the patient in the first mode.
During the second mode of operation the second module 1390 operates independently of the first module 1380 to deliver e.g. ventilatory support and in some embodiments, high flow respiratory support to the patient 300. Thus, the second set of respiratory components of the second module 1390 may include one or more of a flow source such as a blower 1350 configured to generate gas flows through the second set of respiratory components; an inspiratory conduit 110 and a patient interface configured to direct gases from the non-recirculating gases flow to the patient's airway. When the system 1300 is used in the second mode to deliver ventilatory support, the patient interface may be a sealing patient interface, with expired gases returned to the system via expiratory conduit 130 where they are vented to atmosphere or an exhaust (and not recirculated to the patient). Alternatively expired gases may exit the sealing patient interface through port holes in the interface or the expiratory conduit. When the system 1300 is used in the second mode to deliver high flow respiratory support, the patient interface is ideally a non-sealing second patient interface such as a nasal cannula. A humidifier (not shown) may be provided to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode; and a filter upstream of the patient interface may be provided to reduce contamination of the second set of respiratory components upstream of the filter so that they may be reused.
In some embodiments the first module 1380 includes a first gases outlet 1388 and a first gases inlet 1386, and the second module 1390 includes a second gases inlet 1396 and a second gases outlet 1398, wherein the first gases outlet is couplable with the second gases inlet and the first gases inlet is couplable with the second gases outlet for operation of the system 1300 in the first mode, as shown in
Notably, operation of the system 1300 in the first mode permits a first flow of fresh breathing gas 1310 to the system and simultaneously permits return of expired gases to the system due to the coupling between second gases outlet 1398 and first gases inlet 1386. A one way valve 149A may be provided to prevent backflow of returned gases to the fresh gas supply 1310. Meanwhile, operation of the system 1300 in the second mode permits the first flow of fresh breathing gas 1310 into the system independently of the first module 1380 and prevents return of expired gases to the system due to decoupling of second gases outlet 1398 and first gases inlet 1386. Additionally, operation in the second mode prevents release of anaesthetic agents from the system e.g. by provision of a shut off valve in first gas outlet 1388 and/or by switching off vaporizer 150 and/or providing a bypass around vaporizer 150.
Another aspect of the present disclosure relates to switching at the patient end of a breathing circuit delivering breathing gases to a patient 300 in a first mode or a second mode. In one embodiment, a system for delivering breathing gases to a patient, includes a flow modulator 250 configured to generate gas flows through the system in a gas delivery circuit and a switching mechanism forming part of the gas delivery circuit.
Typically, the first patient interface 120 forms a substantially sealing interface with the patient's airway, and receives expiratory gas from the patient. Thus in the first mode, expiratory pathway 930 returns expired gases to the system, specifically to a ventilator or anaesthesia machine of the system where the expired gases are treated e.g. by filtering and released to atmosphere, or recirculated in the anaesthesia machine rebreathing system. Typically, the second patient interface 220 forms a non-sealing interface with the patient's airway and is e.g. a nasal cannula which permits release of expired gases to the environment, around the non-sealing nasal prongs of the cannula.
In one embodiment illustrated in
In some embodiments, the system is configured to receive a user input to select the first mode of operation in which the flow source 1350 generates a low flow rate below a pre-determined flow rate, or the second mode of operation in which the flow source generates a high flow rate at or above the pre-determined flow rate, and wherein the switching mechanism 900 operates responsive to flow rate of gas in the inspiratory gas flow path as generated by the flow source. A bi-stable switch 948 as depicted in
In some embodiments, a user controlled actuator 1440 operates a flow diverter controlling flow of breathing gases toward a patient. An example is shown schematically in
In some embodiments, the system utilising the switching mechanism 900 includes one or more sensors configured to monitor one or more characteristics of gas in the gas delivery circuit, and controls operation of the flow modulator 250 based on said one or more monitored characteristics. These characteristics may indicate one or more of e.g. flow, pressure and CO2. The system controls operation of the flow modulator 250 to generate low flows (e.g. less than 15 LPM) when the one or more sensors indicate breathing gas flow is to the first patient interface 110, and to generate high flows when the one or more sensors indicate breathing gas flow is to the second patient interface 220 using various techniques described herein.
As one of skill would understand when considering this disclosure as a whole, the system utilising the switching mechanism 900 or other switching concepts disclosed herein may include one or more components commonly found in anaesthesia machines, such as a CO2 absorber configured to treat returned expired gas before recirculating to the patient in the first mode, a pressure limiting valve configured to maintain substantially stable pressure in the system in the first mode, a variable volume (e.g. ventilation bag or bellows) for displacement of gases in the first mode, a fresh gas flow for replenishing anaesthetic gas delivered to the patient in the first mode, and a vaporizer for vaporizing volatile anaesthetic agents into breathing gas delivered to the patient in the first mode. Additionally, such a system may include one or more features of a high flow respiratory support system, such as a flow modulator configured to provide high flows through the system and a humidifier configured to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode.
While switching mechanism 900 has been described in the context of a component of a system 1000, it is to be understood that the switching mechanism 900 may be supplied as a component separate from such a system. In this sense, the switching mechanism 900 may be regarded as a breathing gas connector having an inlet port 911 couplable with a gas flow conduit 910 receiving breathing gases from the respiratory support system, a first outlet port 921 couplable with a first gas flow path delivering breathing gas to the patient through a first patient interface 120, a second outlet port 922 couplable with a second gas flow path delivering breathing gas to the patient through a second patient interface 220 and a switching mechanism 940 operable to switch the connector between a first mode of operation the in which the connector directs gas from the inlet port to the first outlet port and a second mode of operation in which the connector directs gas from the inlet port to the second outlet port.
An expiratory gases port 931 is couplable with an expiratory gas conduit, wherein in the first mode, the switching mechanism directs expired gases in the first gas flow path to the expiratory gases conduit. The switching mechanism may be operatively couplable with a controller 1010 of the respiratory support system, wherein operation of the connector switching mechanism 940 may select the first mode of operation of the second mode of operation. The first mode of operation causes the controller to operate the respiratory support system in a first mode in which breathing gases including an anaesthetic agent are delivered to a gas flow conduit 910 coupled with the connector. The second mode of operation causes the controller to operate the respiratory support system in a second mode in which breathing gases are delivered at a pre-determined flow rate to a gas flow conduit 910 coupled with the connector. In some embodiments, connector switching mechanism 940 is operatively couplable with a controller of the respiratory support system such that operation of the connector switching mechanism to select the second mode of operation causes the controller to prevent flow of anaesthetic agents in the breathing gas.
A sensor may be provided to detect one or more characteristics of gas at the first outlet port 921 or the second outlet port 922, said characteristics being used to determine if the connector is coupled to the patient's airway by a first (sealing) patient interface 120 or a second (non-sealing) patient interface 220, the sensor providing input to a controller of the respiratory support system which automatically selects a corresponding mode of operation of the respiratory support system. The one or more characteristics include but are not limited to gas pressure, CO2 concentration; and gas flow rate. A sensor wire locatable inside a conduit providing a gas flow path between the sensor and the respiratory support system controller.
In another aspect, a switching mechanism may be provided by simultaneous use of the first and second patient interfaces 120, 220. Thus when the first and second patient interfaces are applied to the patient simultaneously the first mode is selected, and when only the second patient interface is applied to the patient the second mode of delivery is selected. In one arrangement, the first patient interface is a mask is capable of sealing over the second patient interface being a nasal cannula without occluding flow through the cannula. Inspiratory flow is delivered via the cannula with expiratory gases returned via the face mask. This arrangement can be deployed to deliver anaesthesia in a closed system utilising the cannula to deliver anaesthetic agents to the patient and the mask to return expired gases. Pressure sensors may be used to determine when the mask is applied to the patient and sealed over the cannula, such that when a target pressure is detected at the mask (e.g. inside the mask or within the mask cuff), then the system responds by initiating delivery of anaesthetic agent through the nasal cannula. Commonly owned patent publication WO2015/145390 discloses a mask suitable in this context and is hereby incorporated herein by this reference.
As shown in
An advantage of mode switching according to the examples described in relation to
To facilitate interoperability between different patient interfaces, the novel connector 1700 may be used, which provides a wall 1720 configured to protrude into the wye-piece connector 1750. When connected, the wall 1720 separates the flows in the inspiratory and expiratory flow paths 210, 130 into separate limbs 1710 and 1730. In use, connector 1700 is configured to couple first limb 1710 with a conduit attached to a nasal cannula 224 and is configured to couple second limb 1730 with a conduit attached to a face mask 124. Owing to the separating wall 1720, inspiratory flow to the cannula 224 (see
Typically, a system 1000 with which the patient interfaces shown in
The system may also include a humidifier 420, wherein the breathing gases are heated and/or humidified by the humidifier in the second mode prior to being delivered to the patient. In some embodiments, the breathing gases in the first and/or third modes may be heated and/or humidified by the humidifier 420. Ideally expiratory gases from the patient are returned to the inspiratory gas flow path 210 in the first mode and the third mode. A CO2 absorber 141 may be provided to remove CO2 from the expiratory gases before returning the expiratory gases to the inspiratory gas flow path 210.
Another aspect of the present disclosure provides a multi-lumen assembly 1400 for use with a respiratory support system 1000 as depicted schematically in
A second inspiratory conduit 1420 has a second conduit inflow end couplable with a second gas outlet 1048 of the respiratory support system and is configured to deliver high flow breathing gases to the patient at a flow rate between 20 L/min and 90 L/min. The second inspiratory conduit 1420 has a second conduit outflow end couplable e.g. via a 3 way safety connector, with a second patient interface 220 which is configured to direct flow into an airway of the patient and may be a non-sealing interface such as a nasal cannula.
An expiratory conduit 1430 has an expiratory conduit outflow end couplable with an expired gas inlet 1046 of the respiratory support system. The expiratory conduit 1430 is configured to return expired gases from the patient to the respiratory support system.
In some embodiments, the multi-lumen assembly 1400 includes or is operable with a connector portion 1415 wherein the outflow end of the first inspiratory conduit 1410 and an inflow end of the expiratory conduit 1430 form a common gas flow pathway 1416. A schematic illustration is provided in
In some embodiments, at least a length of the plurality of conduits is arranged co-axially, with the outer wall of an inner lumen defining the inner wall of the next lumen, as shown schematically in
In some embodiments, the retaining mechanism includes a webbing 1452 arranged between at least pairs of the plurality of conduits at intervals or continuously along at least a length of the plurality of conduits which are arranged in a strip. The webbing (or webbing portions)1452 may be frangible to facilitate separation of at least a length of one or more of the plurality of conduits from the group e.g. to separate the second inspiratory conduit 1420 which is coupled with a second patient interface 220, whereas the first inspiratory conduit and expiratory conduits are coupled with a single first patient interface 120.
Alternatively or additionally, the retaining mechanism may include a sheath (or skin) 1454 applied around the plurality of conduits as illustrated in
Alternatively or additionally, the retaining mechanism may include one or more retainers or clips 1456 configured to retain two or more conduits in the plurality of conduits in a group. An example of a retainer/clip 1456 is illustrated in
In some embodiments, the multi-lumen assembly 1400 includes or is operable with a flow switching mechanism operable to direct flow of breathing gas into the first inspiratory conduit 1410 or into the second inspiratory conduit 1420. The switching mechanism is operable by a user to select a mode of support which in turn determines the flow of breathing gas into the first or second inspiratory conduit. The switching mechanism is associated or operably coupled with the respiratory support system 1000 and may take any suitable form such as a button, switch, knob, foot operated switch or pedal or other actuator operable by the user. In the embodiment illustrated, switching mechanism is shown schematically as a switch lever 700.
In some embodiments the switching mechanism is operatively linked with a respiratory support system controller 1010 by electronic means enabling the user to switch modes by use of a touch screen or other electronic interface. In some embodiments, the switching mechanism may be coupled directly with a gas flow diverter controlling flows to the first gas outlet 1044 and second gas outlet 1048 of the system. Alternatively, an electronic switching mechanism which has functional control over valves and/or gas flow diverters or other means used to control flow of gases into the first and second inspiratory conduits 1410, 1420 provides scope for flexibility in the location of the switching mechanism, as well as the potential for central control over other components of the respiratory support system 1000 such as vaporizers, gas sources, gas mixers, flow modulators and the like.
In various embodiments of the multi-lumen assembly 1400 and actuators and connectors that are used with or form part of the multi-lumen assembly, a gas sampling conduit 227 (
System Switching with a CO2 Trigger
Another aspect of the present disclosure relates to CO2 sensing as a means for providing mode switching in a system for delivering breathing gases to a patient. This aspect will be described in the context of a system for providing respiratory support 1000 as described herein, which is operable to deliver breathing gases in a first mode through a first patient interface 120, and in a second mode through a second patient interface 220, The system includes one or more CO2 sensors configured to detect CO2 in expired gas from the patient. The system controller 1010 receives an input from the one or more CO2 sensors and operates the system switching mechanism according to the detected CO2, selecting the first mode when the detected CO2 indicates that the first patient interface is connected to the patient, and selecting the second mode when the detected CO2 indicates that the second patient interface is connected to the patient.
In some embodiments, system controller 1010 switches control when it determines there to have been a change in detected CO2 concentration. However, detection of a change need not be required since comparison with a reference value (e.g. corresponding to typical ambient CO2 levels) may be sufficient for the controller to determine if a first patient interface 120 or a second patient interface 220 is attached to the patient. Detection of the patient circuit (and patient interface) connected to the patient enables the system controller 1010 to automatically select the correct mode of operation to deliver the required respiratory support to the patient. For instance, in the first mode breathing gases are delivered to the patient's airway through the first patient interface which may be a sealing interface, and expired gases are returned to the system by an expiratory gas flow path. Expired gases may be redirected to atmosphere or an exhaust, e.g. when breathing gases are delivered to the patient to provide ventilatory support in the first mode. Alternatively, the first mode may be a rebreathing first mode in which expired gases returned to the system are recirculated via a rebreathing system as disclosed herein, for delivery to the patient via the first patient interface. In a rebreathing first mode the breathing gases may include one or more volatile anaesthetic agents vaporised into the breathing gas by a vaporizer as disclosed herein. In the second mode, breathing gas may be delivered at a high flow rate of at least 20 LPM (for adults) and up to about 90 LPM and these gases may be delivered to the patient through a second patient interface 220 which may be a non-sealing interface such as nasal cannula 224.
The system may include a CO2 sensor associated with a first breathing circuit for delivery of breathing gases in the first mode and/or a second breathing circuit for delivery of breathing gases in the second mode, and the controller 1010 may determine the breathing circuit containing highest concentration of CO2 to be the breathing circuit that is attached to the patient and controls delivery of gases to the determined breathing circuit according to the relevant mode of operation.
Typically, when the one or more CO2 sensors detect CO2 in expired gases in the expiratory gas flow path 130 returning expired gases to the system, the system controller 1010 determines the first breathing circuit including the first patient interface 120 to be attached to the patient. The first patient interface 120 may include a sealing mask 124 or endotracheal tube 126 as depicted in
Since a non-sealing patient interface does not have return conduit for expired gases, a CO2 sensor may be located on the patient end of the interface, e.g. on a prong 226 or the cannula body to which the prongs attach. Alternatively, a sampling conduit 228 can be used to return sampled gas exiting the nares to a CO2 sensor located elsewhere in the apparatus. The sampling conduit 228 may therefore connect with a gas sampling line 227 (
The sampling conduit 228 may provide a flow into the expiratory gas conduit 130 or it may provide a separate conduit in fluid communication with a dedicated gas sampling inlet of system 1000.
A range of different approaches to sensing as a means to provide mode switching in a system for delivering breathing gases to a patient may be used. In one example, pressure in the mask may be monitored by a pressure sensor and used to detect when the mask is in place on the patient. The mask may be placed over the high flow cannula (as in
Alternatively or additionally, sensing in the expiratory flow path of the rebreathing tube may be utilised to determine when the mask is in place on the patient to trigger the switch to rebreathing. The mask may be placed over the high flow cannula (as in
In another arrangement shown in
In yet another arrangement shown in
In some embodiments, the system 1000 includes a first respiratory apparatus 100 delivering breathing gases in the first mode, and a second respiratory apparatus 200 delivering breathing gases in the second mode as described herein. The first respiratory apparatus 100 may thus include one or more of a CO2 absorber configured to treat returned expired gas before recirculating to the patient in the first mode, a pressure limiting valve configured to maintain substantially stable pressure in the system in the first mode; a variable volume (such as a ventilation bag or bellows) for displacement of gases in the first mode, a fresh gas flow for replenishing anaesthetic gas delivered to the patient in the first mode and a vaporizer for vaporizing volatile anaesthetic agents into breathing gas delivered to the patient in the first mode. The second respiratory apparatus 200 includes a flow modulator configured to provide high gas flows through the system and typically includes a humidifier configured to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode.
In preferred embodiments, when the second mode is selected, the system isolates flow of breathing gases from the first respiratory apparatus to the patient so that there is no delivery of anaesthetic agents to the patient 300. In some embodiments the first respiratory apparatus 100 and the second respiratory apparatus 200 are integrated in a unitary machine although that need not be the case. In either case, a humidifier may be provided to condition the breathing gas to a pre-determined temperature and/or humidity before delivery to the patient in the second mode.
In some embodiments the system 1000 includes a display device or monitor 1094 in operative communication with the system controller 1010 and configurable to display one or more CO2 traces based on inputs from the one or more CO2 sensors received by the system controller. The system controller 1010 may automatically determine which of CO2 sensor signals to display on the monitor 1094, selecting the trace corresponding to the CO2 sensor input representing the highest detected CO2 values from the plurality of CO2 sensors or the CO2 values most likely to resemble patient values (e.g. higher than ambient CO2 concentration). Alternatively, the system controller 1010 may cause simultaneous or cycling display of all CO2 traces on monitor 1094, or on one or more a separate monitors which may be devoted solely to CO2 monitoring.
Respiratory Apparatus with Humidification
The components of the respiratory apparatus 100 as shown and described in relation to
The flow source 1030 of the respiratory apparatus 100 may include a flow modulator (such as flow modulator 250 described with reference to
In some embodiments, the flow source 1030 includes the gas supply 1060. The flow source 1030 and/or respiratory apparatus 100 may include one or more valve arrangements adapted to control the rate at which one or more gases, e.g., one or more of NO, O2 and air supplied from the gas supply 1060, are provided to the inspiratory flow path. This may also allow for control of mixing of the one or more gases to a desired composition for use by the respiratory apparatus 100. In alternative embodiments, the flow source 1030 may not include the gas supply 1060. Instead, the flow source 1030 may include one or more containers of compressed air and/or another gas and one or more valve arrangements adapted to control the rate at which the gases leave the one or more containers to provide the flow of breathing gases to the inspiratory flow path.
In other embodiments, the respiratory apparatus 100 is in gas flow communication with a gas delivery apparatus 1040 that is in fluid communication with the gas supply 1060, as illustrated by the broken lines shown in
The gas delivery apparatus 1040 also includes one or more flow meters 1090 for controlling the flow of the breathing gases provided to the respiratory apparatus 100 as shown in
In other embodiments, the respiratory apparatus 100 may include the gas delivery apparatus 1040. The gas delivery apparatus 1040 may be in fluid communication with the flow source 1030 for providing the breathing gases to the flow source 1030 for generating a gas flow in the inspiratory flow path for delivery to the patient 300. Alternatively, the gas delivery apparatus 1040 may replace the flow source 1030 such that the gas outlet 1044 directly provides the flow of breathing gases to the inspiratory flow path.
The respiratory apparatus 100 provides an inspiratory flow path through which a flow of breathing gases is directed into the patient's airway 310. The flow of breathing gases from the flow source 1030 may be conditioned and/or modified in the inspiratory flow path prior to delivery to the patient 300. As illustrated in
The respiratory apparatus 100 is operable in a number of modes of operation, e.g., by the controller 1010. The respiratory apparatus 100 may be operable in a first mode in which the respiratory apparatus 100 delivers breathing gases to the inspiratory flow path and receives return of expired gases via the expiratory flow path. The first mode of operation may be an anaesthetic ventilation mode, which may include providing ventilatory support with or without one or more anaesthetic agents. Typically, the breathing gases are delivered at a low flow rate, e.g., of less than about 15 L/min. In the first mode, the breathing gases may include one or more of NO, O2 and air. The breathing gases may optionally include one or more anaesthetic agents, such as nitric oxide from the flow source 1030 and/or one or more volatile agents from the vaporizer 150, for operation of the respiratory apparatus 100 in the anaesthetic ventilation mode.
In the first mode, the flow of breathing gases may be directed from the flow source 1030 to either the vaporizer 150 or directly to the inspiratory conduit 110 for delivery to the patient 300 as shown in
The respiratory apparatus 100 also provides an expiratory flow path through which a flow of expired gases is received from the patient 300. The first patient interface 120 may be configured to receive expired gases from the patient 300 in the first mode as illustrated in
The respiratory apparatus 100 may also be operable, e.g., by the controller 1010, in a second mode in which the respiratory apparatus delivers breathing gases to the inspiratory flow path at a pre-determined flow rate without return of expired gases from the patient 300. The second mode may be a high flow mode for delivery of high flow respiratory support. Typically, the breathing gases are delivered at a high flow rate, such as in the range of about 20 L/min to about 90 L/min, or in the range of about 40 L/min to about 70 L/min. In other embodiments, the pre-determined flow rate may include about 20 L/min, about 40 L/min or about 70 L/min. The breathing gases may include O2 and/or air in a proportion required for operation of the respiratory apparatus 100 in the second mode.
In the second mode, the flow of breathing gases may be directed from the flow source 1030 to the humidification component 450, and the breathing gases are then directly or indirectly provided to the second inspiratory conduit 210 for delivery to the patient 300 as shown in
The humidification component 450 may operate in at least an invasive mode (for example, for patients with a bypassed airway) and/or a non-invasive mode (for example, for patients or users with breathing masks or nasal cannulas). Each mode can have a number of humidity settings, which can be expressed as a dew point or absolute humidity. The humidification component 450 may be controlled to deliver, at an outlet port 408 of the humidification chamber 400 and/or the patient end of the inspiratory conduit 210, humidified gases having a dew point (or absolute humidity) at or near a predetermined humidity level. For example, a user or clinician can select a setting appropriate for the current mode of operation. A number of humidity settings may be provided. For example, the humidity settings may be equivalent to a dew point of 37° C., 31° C., 29° C., 27° C., or others. The humidity setting equivalent to a dew point of 37° C. may be suitable for invasive therapy (that is, where the patient's upper airways are bypassed) whereas the other humidity settings may be suitable for non-invasive respiratory support, although the humidity settings may not be restricted to a particular type of respiratory support. Alternatively, each humidity setting may be continuously variable between upper and lower limits. A lower humidity setting may be selected by the user or clinician to reduce condensation or “rain-out” in the inspiratory conduit 210, or a higher humidity setting may be selected to improve patient comfort or physiological benefits. Some humidification components 450 disclosed herein can also include a high flow, unsealed mode, or any other modes known to those persons skilled in the art.
The humidification component 450 may provide different levels of humidity for different respiratory support applications. For example, the humidification component 450 can deliver a desired humidity level of about 44 mg/L BTPS (about 37° C. fully saturated) for invasive and/or high flow respiratory support and/or about 32 mg/L BTPS (about 31° C. fully saturated) for non-invasive forms of respiratory support. Other suitable patient comfort settings could also be delivered for various forms of respiratory support.
The conditioned flow of breathing gases from the humidification component 450 may be directed to the second inspiratory conduit 210 and a second patient interface 220 couplable with the patient's airway 310. The second patient interface 220 may form a non-sealing interface with the patient's airway 310, and may include a nasal cannula. Alternatively, the conditioned flow of breathing gases may be returned to the respiratory apparatus 100 and then exit through a dedicated outlet 164 for delivery to the patient 300 (see also
Importantly, the respiratory apparatus 100 does not allow the flow of breathing gases with anaesthetic agents to be directed to the patient 300 in the second mode in some embodiments. Operation of the humidification component 450 may prevent delivery of the one or more volatile anaesthetic agents into the flow of breathing gases in the inspiratory flow path. More particularly, operation of the humidification component 450 may disable operation of the at least one vaporizer 150, or all of the vaporizers 150 in the respiratory apparatus 100. For example, the respiratory apparatus 100 may include a one-way valve or other arrangement to prevent passage of gas flow, especially any volatile anaesthetic agents, from the vaporizer 150 to the second inspiratory conduit 210 when the humidification component 450 is in operation. Such arrangements have been described in the foregoing.
The respiratory apparatus 100 may advantageously enable selective operation of the one or more vaporizers 150 and the humidification component 450. The respiratory apparatus 100 may include an optional switching mechanism 1020 as illustrated in
The respiratory apparatus 100 may be configurable in gas flow communication with one or more of a pressure limiting valve 143, 146 configured to maintain substantially stable pressure in the respiratory apparatus 100 in the first mode, a variable volume or bellows 145 for displacement of gases in the first mode, a fresh gas flow (FGF) for replenishing breathing gases delivered to the patient 300 in the first mode (see also
The respiratory apparatus 100 also includes a mount 160 which is couplable with a vaporizer 150 and a humidification component 450 as shown in
In some embodiments, the mount 160 is couplable with two or more vaporizers 150 (not shown), in addition to the humidification component 450. The humidification component 450 may be positioned on the mount 160 with a vaporizer 150 located on either side of the humidification component 450. This may enable the housing of the humidification component 450 to cooperatively engage with each of the housings of the vaporizers 150, such as to disable operation of both vaporizers 150 when the humidification component 450 is in operation. This will be described in more detail in relation to
The humidification component 450 may be configured for use with the respiratory apparatus 100 of
In some embodiments, the humidification base unit 410 is configured to be coupled with the mount 160. A housing of the humidification base unit 410 may be configured to be slidably received onto the mount 160. For example, the mount 160 may include a plurality of slots and the housing of the humidification base unit 410 may be slidably receive into one of the slots, such as shown by the mount 160 of
The humidification chamber 400 includes an inlet port 406 for receiving a flow of breathing gases from the respiratory apparatus 100, and an outlet port 414 for delivering the conditioned flow of breathing gases to the patient 300. The outlet port 414 is couplable with the inspiratory conduit 210 for delivering the conditioned flow of breathing gases to the patient 300 via a patient interface (e.g., a sealing or non-sealing patient interface). The inspiratory conduit 210 may be coupled with a second patient interface 220, for example, a nasal cannula, for delivering breathing gases to the patient's airway 310. The humidification base unit 410 includes a heating element 412, such as a heating coil, to heat liquid in the humidification chamber 400. The heating element 412 of the humidification base unit 410 is electrically connected to the mount 160 as shown in
In some embodiments, the humidification chamber 400 includes a liquid inlet that connects to a liquid reservoir for refilling of the humidification chamber 400. The humidification chamber 400 may also include a flow control mechanism to control flow of liquid into the humidification chamber 400. The humidification chamber 400 may include at least one sensor for detecting a level of liquid in the humidification chamber 400. The humidification chamber 400 may include a float valve for controlling a level of liquid in the humidification chamber 400. For example, U.S. Pat. No. 5,445,143 disclosed a dual float valve humidification chamber which would be suitable for embodiments of the present disclosure, the disclosure of which is incorporated herein by this reference.
In some embodiments, the humidification component 450 is couplable with the mount 160 via an adapter 430.
As illustrated in
Advantageously, in some embodiments of the disclosure, operation of the humidification component 450 prevents delivery of the one or more volatile anaesthetic agents into the flow of breathing gases in the inspiratory flow path. More particularly, operation of the humidification component 450 may disable operation of the at least one vaporizer 150, as described in relation to
The vaporizer 150 and the humidification component 450 may include the same locking element as shown in
It is advantageous for the locking element of the vaporizer 150 and the humidification component 450 to include a pair of locking pins, with a pin on each side of the housing of the vaporizer 150 and humidification component 450. This is useful as the mount 160 may concurrently receive one or more vaporizers 150 as well as the humidification component 450. If the humification component 450 is positioned between the two vaporizers 150, this enables the vaporizers 150 to both be disabled upon operation of the humidification component 450, as the locking pins 424A and 424B will cause retraction one of the locking pins 154A and 154B of the two vaporizers 150.
It is to be understood that the humidification component 450 and the vaporizer 150 may be operable using manual or electronic switching control means to achieve various operational states, such as wherein operation of the humidification component 450 is enabled while the vaporizer 150 is enabled, or wherein operation of the humidification component 450 is disabled while the vaporizer 150 is enabled, or wherein operation of the humidification component 450 is enabled while the vaporizer 150 is disabled, or operation of the humidification component 450 is disabled while the vaporizer 150 is disabled.
As illustrated in
In other embodiments, the interlocking mechanism and the locking elements as illustrated in
Upon activation of the switching mechanism to operate the humidification component 450, the vaporizer(s) 150 may be prevented from operating until the switching mechanism is deactivated. Similarly, upon activation of the switching mechanism to operate one of the vaporizers 150, the humidification component 450 and/or other vaporizers 150 may be prevented from operating until the switching mechanism is deactivated.
The switching mechanism 1020 may include one or more of a gas flow diverter, bi-stable switch, pneumatic switch, rotary switch, lever, knob or other actuator which is operable by a user. For example, the switching mechanism 1020 may include each of the vaporizer 150 and the humidification component 450 being operable by a switch. The switch may be a mechanical or electronic switch. The switch may be a rotary switch operable by a user through rotation of a dial 158 on the vaporizer 150 and a dial 428 on the humidification component 450 as described in relation to
The switching mechanism 1020 may also be coupled with the interlocking mechanism of the respiratory apparatus 100 as described in relation to
Enabling and disabling of each of the humidification component 450 and the one or more vaporizers 150 may occur through a variety of suitable means and in some embodiments, may involve electronic and/or mechanical actuators. These actuators may be operatively linked to the switches and interlocks discussed in relation to
When the respiratory apparatus 100 is operated in the first mode, which may be an anaesthetic ventilation mode (e.g., providing ventilatory support with or without anaesthetic agents), a switching mechanism 700 disables operation of the O2 gas line having the flow meter 190D. In contrast, when the respiratory apparatus 100 is operated in the second mode, which is ideally a high flow respiratory support mode, the switching mechanism 700 disables operation of the flow meter 190C and enables operation of the flow meter 190D for delivering O2 and/or air at a fixed flow rate to the patient 300. The flow rate may be in the range of about 20 L/min to about 90 L/min. The flow rate may be in the range of about 40 L/min to about 70 L/min. The flow rate may be about 20 L/min, about 40 L/min or about 70 L/min.
In
In the second mode of operation, the CO2 absorber 141 may be further configured to condition the breathing gases in the inspiratory flow path to a pre-determined temperature and/or humidity before delivery to the patient 300. The CO2 absorber 141 in the second mode may be configured to condition the breathing gases to the pre-determined temperature and/or humidity by one or both of changing an amount of soda lime present in the CO2 absorber 141, and changing an amount of CO2 provided to the soda lime present in the CO2 absorber 141.
For example, the reaction of the soda lime CO2 absorber 141 could be utilised to humidify a high flow of gases. A switch could be employed in the respiratory apparatus (mechanical, electronic or otherwise), to switch the CO2 absorber 141 between the anaesthetic ventilation mode and high flow mode. Furthermore, the geometry of the soda lime may be adjusted to change the level of humidification and increase the humidity to achieve suitable levels for high flow respiratory support. Additionally/alternatively, the amount of CO2 provided to the soda lime could be adjusted to increase the reaction with the soda lime and thus, increase the humidity. Accordingly, the CO2 absorber 141 could be employed in the second mode (e.g., high flow mode) of the respiratory apparatus 100 to provide additional humidification of the flow of gases as shown in
The two modes of operation illustrated in
The sensor 1050 may include an electronic and/or mechanical feature for detecting the coupling. For example, the sensor 1050 may detect a change in an electrical property, such as resistance, capacitance or inductance in an electrical circuit when the humidification component 450 is coupled with the mount 160. Alternatively, the humidification component 450 may include a machine-readable component associated with the housing 422, such as a radio-frequency identification detection (RFID) device which is able to be detected by the sensor 1050 upon coupling of the humidification component 450 with the mount 160. In other embodiments, the respiratory apparatus may exclude a sensor 1050 and instead provide a mechanical arrangement for detecting the coupling, such as through a lock and key arrangement or the like, as would be appreciated by a person skilled in the art.
Embodiments of the present disclosure provide configurations that allow easy interchange between respiratory support via high flow, and respiratory support by anaesthetic ventilation/anaesthetic agent delivery via the anaesthetic machine.
Some embodiments provide a single machine that provides the functionality of both high flow respiratory support and a rebreathing system for delivery of anaesthesia, which can be easily transitioned or switched between a high flow mode and an anaesthesia machine (rebreathing) mode. Desirably, this allows a clinician to easily switch between deployment of high flow respiratory support and a rebreathing system and then subsequently inducing/ventilating the patient. This reduces the overall number of components, simplifying the working environment and making it easier for an anaesthetist to perform required tasks during procedures involving high flow therapies in addition to administration of anaesthesia.
When switching to a high flow mode from a rebreathing mode, for safety reasons it is desirable that the transition stops the delivery of gases from the anaesthesia machine. Uncontrolled delivery of O2 outside of the re-breathing system (e.g. when the mask is removed from the patient) could pose a fire risk, and there could be wastage of anaesthetic gas, as well as unintentional release of anaesthetic gases to the operating environment which could not only contaminate the high flow respiratory support gases, but impact the performance of individuals in the operating environment. Embodiments of the present invention address one or more of these problems.
Also described herein are various embodiments, apparatuses, connectors, assemblies, accessories, devices and the like for achieving switching between modes of respiratory support. Some of these provide the convenience of controlling mode selection when the user is not situated at the “machine” by providing switching actuators closer to the patient, or the clinician. Some embodiments provide for automatic selection of modes of operation by monitoring characteristics of gases in the system, such as gas pressure and CO2 concentration in expired gases. Not only do these features improve convenience and operability of a system that provides these modes of respiratory support, they also have the capability to improve patient safety.
Humidification of breathing gases delivered during high flow respiratory support can be important because without it, gases may have a drying effect on the airways which can lead to damage and other complications. Embodiments of the present disclosure provide a respiratory apparatus that allows for humidification of breathing gases that are delivered during high flow respiratory support. The respiratory apparatus includes a mount that is couplable with a humidification component for conditioning a flow of breathing gases to a pre-determined temperature and/or humidity before delivery to the patient.
Embodiments of the respiratory apparatus may also advantageously provide an interlocking mechanism to prevent simultaneous operation of the humidification component and one or more vaporizers. This may desirably prevent delivery of volatile anaesthetic agents to the patient during high flow respiratory support. Furthermore, the respiratory apparatus may also include a switching mechanism configured to enable selective operation of the humidification component and the at least one vaporizer. The switching mechanism which may be coupled with the interlocking mechanism to provide for easy of switching and safe transition between the anaesthetic ventilation mode and high flow mode of the respiratory apparatus during medical procedures requiring both forms of respiratory support.
It is to be understood that various modifications, additions and/or alternatives may be made to the parts previously described without departing from the ambit of the present invention as defined in the claims appended hereto.
The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features. Where, in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.
Where any or all of the terms “comprise”, “comprises”, “comprised” or “comprising” are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components or group thereof.
It is to be understood that the following claims are provided by way of example only, and are not intended to limit the scope of what may be claimed in future. Features may be added to or omitted from the claims at a later date so as to further define or re-define the invention or inventions.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2021/062153 | 12/22/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63129986 | Dec 2020 | US | |
| 63129990 | Dec 2020 | US |
