Patent Application
20240024603
The present invention relates to systems for providing respiratory support to a subject that utilise a connector for coupling with an invasive respiratory device. It also relates specifically but not exclusively to a connector for coupling with an invasive respiratory device and a kit for a system for providing respiratory support to a subject.
Patients usually require a form of respiratory support during medical procedures, particularly medical procedures which involve sedation or anaesthesia. A patient can be spontaneously breathing or apnoeic during a medical procedure or a part thereof. Invasive respiratory devices (such as an endotracheal tube (ETT), laryngeal mask (LMA) etc.) are used to provide ventilator support (e.g., by providing oxygenation and pressure support) to a patient when the patient is apnoeic.
Invasive respiratory devices such as ETTs and tracheostomy tubes can also be used to provide respiratory support to patients who are spontaneously breathing. These patients may not be undergoing a medical procedure and may be in the intensive care unit (ICU).
Weaning from ventilatory support is an important part of recovery for intubated patients in the operating theatre or in the ICU. The term “weaning” refers to the process of reducing ventilatory support, ultimately resulting in a patient breathing spontaneously and being extubated (i.e., the invasive respiratory device is removed). Prior to extubation, clinicians attempt to ensure that the patient has both sufficient respiratory drive and also sufficient respiratory strength to transit safely to stable spontaneous breathing. The process is not always successful and sometimes patients are ‘weaned’ and then extubated only for the clinician to find that they are incapable of breathing spontaneously and may have to be re-intubated.
Thus, there is a need to further improve the success of the weaning and extubation process preferably before the patient is extubated, so that the chances of re-intubation are reduced and the patient is more likely to succeed in breathing spontaneously post-extubation. It would also be desirable to provide respiratory support by oxygenating the patient and clearing carbon dioxide (CO2) during the weaning process.
There is also a need to improve oxygenation and CO2 clearance in patients with an invasive respiratory device, who are spontaneously breathing and who may not be undergoing a medical procedure.
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.
In one aspect, the present invention provides a system for providing respiratory support to a subject, the system including: a flow source for providing a gas at a selected flow rate; an invasive respiratory device couplable with an airway of the subject; and a connector for coupling with the invasive respiratory device, the connector including a main body having: a gases port for receiving a flow of gas from the flow source, wherein the gases port includes an inlet and an outlet; an outlet port for outflow of gases from the main body; and a device port couplable with the invasive respiratory device; wherein the connector is configured to receive the flow of gas from the flow source via the inlet of the gases port, and to deliver a jet flow of gas through the outlet of the gases port, wherein the system is configured to generate a pressure of at least about 2 cmH2O about the device port when in use.
In some embodiments, the pressure about the device port is between about 2 cm H2O and about 20 cmH2O. The pressure about the device port may be between about 2 cmH2O to about 10 cmH2O during inspiration of the subject. Preferably, the pressure about the device port is between about 2 cmH2O and about 5 cmH2O during inspiration of the subject. The pressure about the device port may be between about 5 cmH2O and about 20 cmH2O during expiration of the subject. Preferably, the pressure about the device port is between about 5 cmH2O and about 10 cmH2O during expiration of the subject.
In some embodiments, a pressure loss between the outlet of the gases port and the outlet port of the connector is less than about 20 cmH2O when in use. Preferably, the pressure loss between the outlet of the gases port and the outlet port of the connector is less than about 12 cmH2O when in use. A ratio of the pressure about the device port to the pressure loss between the outlet of the gases port and the outlet port of the connector may be in a range of more than 0 to about 1:1.
In some embodiments, a pressure loss between the device port and the outlet port of the connector is less than about 20 cmH2O when in use.
In some embodiments, the system includes a pressure loss between the flow source and the outlet port of the connector of less than about 20 cmH2O when in use.
In another aspect, the present invention provides a system for providing respiratory support to a subject, the system including: a flow source for providing a gas at a selected flow rate; an invasive respiratory device couplable with an airway of the subject; and a connector for coupling with the invasive respiratory device, the connector including a main body having: a gases port for receiving a flow of gas from the flow source, wherein the gases port includes an inlet and an outlet; an outlet port for outflow of gases from the main body; and a device port couplable with the invasive respiratory device; wherein the connector is configured to receive the flow of gas from the flow source via the inlet of the gases port, and to deliver a jet flow of gas through the outlet of the gases port; wherein a pressure loss between the device port and the outlet port of the connector is less than about 20 cmH2O when in use.
In some embodiments, the system is configured to generate a pressure of at least about 2 cmH2O about the device port when in use. The pressure about the device port may be between about 2 cmH2O and about 20 cmH2O. The pressure about the device port may be between about 2 cmH2O and about 10 cmH2O during inspiration of the subject. Preferably, the pressure about the device port is between about 2 cmH2O and about 5 cmH2O during inspiration of the subject. The pressure about the device port may be between about 5 cmH2O and about 20 cmH2O during expiration of the subject. Preferably, the pressure about the device port is between about 5 cmH2O and about 10 cmH2O during expiration of the subject.
In some embodiments, a pressure loss between the outlet of the gases port and the outlet port of the connector is less than about 20 cmH2O when in use. Preferably, the pressure loss between the outlet of the gases port and the outlet port of the connector is less than about 12 cmH2O when in use. A ratio of the pressure about the device port to the pressure loss between the outlet of the gases port and the outlet port of the connector may be in a range of more than 0 to about 1:1.
The system may also include a pressure loss between the flow source and the outlet port of the connector of less than about 20 cmH2O when in use.
In another aspect, the present invention provides a system for providing respiratory support to a subject, the system including: a flow source for providing a gas at a selected flow rate; an invasive respiratory device couplable with an airway of the subject; and a connector for coupling with the invasive respiratory device, the connector including a main body having: a gases port for receiving a flow of gas from the flow source, wherein the gases port includes an inlet and an outlet; an outlet port for outflow of gases from the main body; and a device port couplable with the invasive respiratory device; wherein the connector is configured to receive the flow of gas from the flow source via the inlet of the gases port, and to deliver a jet flow of gas through the outlet of the gases port, wherein a pressure loss between the outlet of the gases port and the outlet port of the connector is less than about 20 cmH2O when in use.
Preferably, the pressure loss between the outlet of the gases port and the outlet port of the connector is less than about 12 cmH2O when in use.
In some embodiments, a pressure loss between the device port and the outlet port of the connector is less than about 20 cmH2O when in use.
In some embodiments, the system includes a pressure loss between the flow source and the outlet port of the connector of less than about 20 cmH2O when in use.
In some embodiments, the system is configured to generate a pressure of at least about 2 cmH2O about the device port when in use. The pressure about the device port may be between about 2 cmH2O and about 20 cmH2O. The pressure about the device port may be between about 2 cmH2O and about 10 cmH2O during inspiration of the subject. Preferably, the pressure about the device port is between about 2 cmH2O and about 5 cmH2O during inspiration of the subject. The pressure about the device port may be between about 5 cmH2O and about 20 cmH2O during expiration of the subject. Preferably, the pressure about the device port is between about 5 cmH2O and about 10 cmH2O during expiration of the subject.
In some embodiments, a ratio of the pressure about the device port to the pressure loss between the outlet of the gases port and the outlet port of the connector is in a range of more than 0 to about 1:1.
In some embodiments of the above systems disclosed herein, the flow source is configured to provide a continuous flow of the gas at the selected flow rate. The selected flow rate may include a fixed flow rate or a variable flow rate. The selected flow rate may be in a range of about 10 L/min to about 120 L/min. The selected flow rate may be in a range of about 20 L/min to about 90 L/min. The selected flow rate may be in a range of about 20 L/min to about 70 L/min. The selected flow rate may be in a range of about 40 L/min to about 70 L/min. In other embodiments of the above systems disclosed herein, the selected flow rate is in a range of about 0.5 L/min to about 25 L/min.
In some embodiments of the above systems disclosed herein, the systems further include a filter couplable with the outlet port of the connector for filtering the gases from the main body. The filter may be non-removable and/or integral with the outlet port. Alternatively, the filter may be removably couplable with the outlet port of the connector.
In some embodiments of the above systems disclosed herein, the connector further includes a filter couplable with the outlet port of the connector for filtering the gases from the main body. The filter may be non-removable and/or integral with the outlet port. The filter may be one of a radial filter or a receptacle filter. Alternatively, the filter may be removably couplable with the outlet port of the connector.
In some embodiments of the above systems disclosed herein, the connector further includes one or more gas sampling ports for sampling one or more characteristics of the gases in the main body. The one or more characteristics of the gases may include pressure, flow rate, concentration, gas constituents, temperature, humidity, contaminants, aerosols and/or pathogens. The one or more gas sampling ports may be located on one or both of the outlet port and the main body of the connector.
In some embodiments of the above systems disclosed herein, the jet flow of gas delivered through the outlet of the gases port has a velocity is in a range of about 5 m/s to about 60 m/s. The outlet of the gases port may have a hydraulic diameter in a range of about 2 mm to about 10 mm. The hydraulic diameter may be in a range of about 5 mm to about 8 mm.
In some embodiments of the above systems disclosed herein, a distance from the outlet of the gases port to a distal end portion of the invasive respiratory device when coupled to the device port is in a range of about 0 mm to about 60 mm. Preferably, the distance is in a range of about 10 mm to about 30 mm.
In some embodiments of the above systems disclosed herein, the outlet of the gases port has a cross-sectional area in a range of about 10 mm2 to about 60 mm2. Preferably, the cross-sectional area is in a range of about 19 mm2 to about 50 mm2. A ratio of the cross-sectional area of the outlet of the gases port to the distance from the outlet of the gases port to the distal end portion of the invasive respiratory device may be between about 1:1 and about 1:10.
In some embodiments of the above systems disclosed herein, the connector further includes an expiratory flow path defined between the device port and the outlet port, and wherein the expiratory flow path has a minimum cross-sectional area of at least about 25 mm2. The minimum cross-sectional area may be at least about 30 mm2. The minimum cross-sectional area may be at least about 35 mm2.
In some embodiments of the above systems disclosed herein, the minimum cross-sectional area of the expiratory flow path is greater than a cross-sectional area of the outlet of the gases port. A ratio of the minimum cross-sectional area of the expiratory flow path to the cross-sectional area of the outlet of the gases port may be between about 2:1 and about 3:1.
In some embodiments of the above systems disclosed herein, the outlet of the gases port is disposed between the inlet of the gases port and a distal end portion of the invasive respiratory device when coupled to the device port. The outlet of the gases port may be disposed between the inlet of the gases port and the device port. Preferably, the outlet of the gases port is disposed between the inlet of the gases port and a distal end portion of the device port.
In some embodiments of the above systems disclosed herein, the gases port further includes a flow constriction for providing the jet flow of gas through the outlet of the gases port. The flow constriction may be disposed between the inlet of the gases port and the device port.
In some embodiments of the above systems disclosed herein, the flow constriction includes a nozzle having the outlet of the gases port through which the jet flow of gas is delivered.
In some embodiments of the above systems disclosed herein, the flow constriction includes the outlet of the gases port having a plurality of apertures through which the jet flow of gas is delivered.
In some embodiments of the above systems disclosed herein, the flow constriction includes a tapered region for constricting the flow of gas prior to exiting the outlet. An angle of a wall of the tapered region relative to a longitudinal axis of the flow constriction may be in a range of more than 0 degrees to about 45 degrees. Preferably, the angle is between about 2 degrees and about 20 degrees.
In some embodiments of the above systems disclosed herein, the connector further includes an inlet channel in fluid communication with the inlet of the gases port, and wherein the flow constriction is associated with the inlet channel. The flow constriction may be formed integrally with the inlet channel. Alternatively, the connector may be configured to receive an insert positionable within the inlet channel to provide the flow constriction.
In some embodiments of the above systems disclosed herein, the connector further includes an outlet channel in fluid communication with the outlet port. A cross-sectional area of the outlet channel may be greater than a cross-sectional area of the outlet of the gases port.
In some embodiments of the above systems disclosed herein, the inlet channel and the outlet channel are positioned adjacent to one another. The inlet channel and the outlet channel may be coaxial. Alternatively, a longitudinal axis of the inlet channel and a longitudinal axis of the outlet channel may be offset relative to each other.
In some embodiments of the above systems disclosed herein, the system further includes an interface conduit connectable between the gases port of the connector and the flow source for providing fluid communication. The interface conduit may be configured to heat the gas provided by the flow source to a selected temperature before delivery to the gases port of the connector.
In some embodiments of the above systems disclosed herein, the system further includes a humidifier configured to condition the gas provided by the flow source to a selected temperature and/or humidity.
In another aspect, the present invention provides a connector for coupling with an invasive respiratory device, the connector including a main body having: a gases port for receiving a flow of gas from a flow source at a selected flow rate, wherein the gases port includes an inlet and an outlet; an outlet port for outflow of gases from the main body; and a device port couplable with the invasive respiratory device; wherein the connector is configured to receive the flow of gas from the flow source via the inlet of the gases port, and to deliver a jet flow of gas through the outlet of the gases port, wherein the jet flow of gas delivered through the outlet of the gases port has a velocity in a range of about 5 m/s to about 60 m/s.
In some embodiments, the outlet of the gases port has a hydraulic diameter in a range of about 2 mm to about 10 mm. The hydraulic diameter may be in a range of about 5 mm to about 8 mm.
In some embodiments, the outlet of the gases port has a cross-sectional area in a range of about 10 mm2 to about 60 mm2. Preferably, the cross-sectional area is in a range of about 19 mm2 to about 50 mm2.
In some embodiments, a distance from the outlet of the gases port to a distal end portion of the invasive respiratory device when coupled to the device port is in a range of about 0 mm to about 60 mm. Preferably, the distance is in a range of about 10 mm to about 30 mm. A ratio of the cross-sectional area of the outlet of the gases port to the distance from the outlet of the gases port to the distal end portion of the invasive respiratory device may be between about 1:1 and about 1:10. The ratio may be between about 1:1 and about 1:5.
In some embodiments, the connector further includes an expiratory flow path defined between the device port and the outlet port, and wherein the expiratory flow path has a minimum cross-sectional area of at least about 25 mm2. The minimum cross-sectional area may be at least about 30 mm2. The minimum cross-sectional area may be at least about 35 mm2.
In some embodiments, the minimum cross-sectional area of the expiratory flow path is greater than a cross-sectional area of the outlet of the gases port. A ratio of the minimum cross-sectional area of the expiratory flow path to the cross-sectional area of the outlet of the gases port may be between about 2:1 and about 3:1.
In some embodiments, the flow of gas at the selected flow rate has a velocity in a range of about 5 m/s to about 60 m/s.
In some embodiments, the gases port further includes a flow constriction for providing the jet flow of gas through the outlet of the gases port. The flow constriction may be disposed between the inlet of the gases port and the device port.
In some embodiments, the flow constriction includes a nozzle having the outlet of the gases port through which the jet flow of the gas is delivered.
In some embodiments, the flow constriction includes the outlet of the gases port having a plurality of apertures through which the jet flow of the gas is delivered.
In some embodiments, the flow constriction includes a tapered region for constricting the flow of gas prior to exiting the outlet. An angle of a wall of the tapered region relative to a longitudinal axis of the flow constriction may be in a range of more than 0 degrees to about 45 degrees. The angle may be between about 2 degrees and about 20 degrees.
In some embodiments, the gases port further includes a conditioning portion, preferably adjacent the outlet, having a substantially constant cross-sectional area for conditioning the flow of the gas prior to exiting the outlet. The conditioning portion may be located between the tapered region and the outlet of the gases port. The conditioning portion may have a length in a range of more than 0 mm to about 60 mm.
In some embodiments, the connector further includes an inlet channel in fluid communication with the inlet of the gases port, and wherein the flow constriction is associated with the inlet channel. The flow constriction may be formed integrally with the inlet channel. Alternatively, the connector may be configured to receive an insert positionable within the inlet channel to provide the flow constriction.
In some embodiments, the outlet of the gases port has a cross-sectional shape including one of oval, triangular, elliptical or circular. The outlet of the gases port may include an angled opening for directing the jet flow of gas along or towards a wall of the main body of the connector and/or a wall of the invasive respiratory device when coupled to the device port. The angled opening may be relative to a transverse axis of the flow constriction.
In some embodiments, the connector further includes at least one locating feature configured to maintain a desired distance between the outlet of the gases port and a distal end portion of the invasive respiratory device when coupled to the device port. The at least one locating feature may be positioned on the device port and/or the main body of the connector. The at least one locating feature may include an engagement structure for releasably coupling with the invasive respiratory device or an adapter connected to the invasive respiratory device.
In another aspect, a connector for coupling with an invasive respiratory device is disclosed herein, the connector including a main body having: a gases port for receiving a flow of gas from a flow source at a selected flow rate, wherein the gases port includes an inlet and an outlet; an outlet port for outflow of gases from the main body; and a device port couplable with the invasive respiratory device; wherein the connector is configured to receive the flow of gas from the flow source via the inlet of the gases port, and to deliver a jet flow of gas through the outlet of the gases port; and wherein the connector further includes an expiratory flow path defined between the device port and the outlet port, wherein the expiratory flow path has a minimum cross-sectional area of at least about 25 mm2.
The minimum cross-sectional area may be at least about 30 mm2. The minimum cross-sectional area may be at least about 35 mm2.
In some embodiments, the minimum cross-sectional area of the expiratory flow path is greater than a cross-sectional area of the outlet of the gases port. A ratio of the minimum cross-sectional area of the expiratory flow path to the cross-sectional area of the outlet of the gases port may be between about 2:1 and about 3:1.
In some embodiments, the gases port further includes a flow constriction for providing the jet flow of gas through the outlet of the gases port. The flow constriction may be located between the inlet of the gases port and the device port such that it does not obstruct the expiratory flow path. The connector may further include an inspiratory flow path defined between the inlet of the gases port and the device port, wherein the flow constriction is disposed in the inspiratory flow path.
In some embodiments, the connector further includes an inlet channel and an outlet channel in flow communication with the inlet of the gases port and the outlet port, respectively, the flow constriction being associated with the inlet channel. A cross-sectional area of the outlet channel may be greater than a cross-sectional area of the outlet of the gases port. The inlet channel and the outlet channel may be positioned adjacent to one another. The inlet channel and the outlet channel may be coaxial. Alternatively, a longitudinal axis of the inlet channel and a longitudinal axis of the outlet channel may be offset relative to each other.
In some embodiments, the flow constriction includes a nozzle having the outlet of the gases port through which the jet flow of gas is delivered.
In some embodiments, the flow constriction includes the outlet of the gases port having a plurality of apertures through which the jet flow of gas is delivered.
In some embodiments, the flow constriction includes a tapered region for constricting the flow of gas prior to exiting the outlet. An angle of a wall of the tapered region relative to a longitudinal axis of the flow constriction may be in a range of more than 0 degrees to about 45 degrees. The angle may be between about 2 degrees and about 20 degrees.
In another aspect, a connector for coupling with an invasive respiratory device is disclosed herein, the connector including a main body having: a gases port having an inlet for receiving a flow of gas from a flow source at a selected flow rate; an outlet port for outflow of gases from the main body; and a device port couplable with the invasive respiratory device; wherein the connector further includes: an inlet channel in flow communication with the inlet of the gases port, wherein the connector is configured to receive an insert positionable within the inlet channel for providing an outlet; and wherein the connector is configured to receive the flow of gas from the flow source via the inlet of the gases port, and to deliver a jet flow of gas through the outlet provided by the insert.
In some embodiments, the connector is configured to receive the insert positionable within the inlet channel for providing a flow constriction, wherein the flow constriction provides the jet flow of gas through the outlet. The flow constriction may be disposed between the inlet of the gases port and the device port.
In some embodiments, the inlet channel includes at least one locating feature configured to guide positioning of the insert within the inlet channel. The at least one locating feature of the inlet channel may include one or more of: a protrusion, a groove, a rib, and/or a flange on a wall of the inlet channel.
Additionally/alternatively, the insert may include at least one locating feature to guide positioning of the insert within the inlet channel. The at least one locating feature of the insert may include a region of reduced cross-sectional area for engaging with a wall of the inlet channel.
In some embodiments, a length of the insert is selected based on a desired distance of the outlet from a distal end portion of the invasive respiratory device when coupled to the device port.
In some embodiments, the connector further includes at least one locating feature configured to maintain a desired distance between the outlet and a distal end portion of the invasive respiratory device when coupled with the device port.
In some embodiments, the connector further includes an outlet channel in flow communication with the outlet port. The outlet channel and the inlet channel may be positioned adjacent to one another. The inlet channel and the outlet channel may be coaxial. Alternatively, a longitudinal axis of the inlet channel and a longitudinal axis of the outlet channel may be offset relative to each other. In some embodiments, a cross-sectional area of the outlet channel is greater than a cross-sectional area of the outlet.
In another aspect, an insert for a connector couplable with an invasive respiratory device is disclosed herein, the connector including a main body having: a gases port including an inlet for receiving a flow of gas from a flow source at a selected flow rate; an outlet port for outflow of gases from the main body; and a device port couplable with the invasive respiratory device; wherein the connector further includes: an inlet channel in fluid communication with the inlet of the gases port, wherein the insert is configured to be positioned in the inlet channel of the connector to provide an outlet, and wherein the connector is configured to receive the flow of gas from the flow source via the inlet of the gases port, and to deliver a jet flow of gas through the outlet provided by the insert.
In some embodiments, the insert is configured to be positioned in the inlet channel of the connector to provide a flow constriction, and wherein the flow constriction provides the jet flow of gas through the outlet. The flow constriction may be disposed between the inlet of the gases port and the device port.
In some embodiments, the flow constriction is formed between the insert and a wall of the inlet channel. The insert may further include at least one locating feature to guide positioning of the insert within the inlet channel. The at least one locating feature may include a region of reduced cross-sectional area for engaging with a wall of the inlet channel.
In some embodiments, the insert includes a length selected based on a desired distance of the outlet from a distal end portion of the invasive respiratory device when coupled to the device port of the connector.
In another aspect, a connector for coupling with an invasive respiratory device is disclosed herein, the connector including a main body having: a gases port for receiving a flow of gas from a flow source at a selected flow rate, wherein the gases port includes an inlet and an outlet; an outlet port for outflow of gases from the main body; and a device port couplable with the invasive respiratory device; wherein the connector is configured to receive the flow of gas from the flow source via the inlet of the gases port, and to deliver a jet flow of gas through the outlet of the gases port, and wherein the connector is configured to change the direction of gas flow within the main body of the connector when in use.
In some embodiments, the gases port further includes a flow constriction for providing the jet flow of gas through the outlet of the gases port. The flow constriction may be disposed between the inlet of the gases port and the device port.
In some embodiments, the connector passively changes the direction of gas flow in response to inspiration and/or expiration of the subject. The connector may be configured to direct the jet flow of gas towards the device port during inspiration of the subject and towards the outlet port during expiration of the subject.
In some embodiments, the jet flow of gas is directed towards a wall of the main body of the connector opposing the outlet of the gases port. The flow constriction and/or the outlet of the gases port may be angled relative to the main body of the connector in order to direct the jet flow of gas towards the opposing wall.
In some embodiments, the opposing wall is shaped and/or positioned such that the jet flow of gas attaches to a surface of the opposing wall. The opposing wall of the main body may be curved or sloped. The opposing wall may form at least part of a wall of the outlet port.
In some embodiments, the device port and the outlet port are located at an acute angle relative to each other.
In another aspect, a connector for coupling with an invasive respiratory device is disclosed herein, the connector including a main body having: a gases port for receiving a flow of gas from a flow source at a selected flow rate, wherein the gases port includes an inlet and an outlet; an outlet port for outflow of gases from the main body; and a device port couplable with the invasive respiratory device; wherein the connector is configured to receive the flow of gas from the flow source via the inlet of the gases port, and to deliver a jet flow of gas through the outlet of the gases port, and wherein the connector further includes at least one flow altering feature for altering at least one characteristic of the jet flow of gas exiting the outlet.
In some embodiments, the gases port further includes a flow constriction for providing the jet flow of gas through the outlet of the gases port. The flow constriction may be disposed between the inlet of the gases port and the device port.
In some embodiments, the at least one flow altering feature is configured to create or increase a degree of turbulent or chaotic flow of the jet flow of gas exiting the outlet.
In some embodiments, the at least one flow altering feature is associated with the flow constriction and/or the outlet of the gases port. The at least one flow altering feature may include the flow constriction and/or the outlet of the gases port having one or both of: an internal wall with a spiral or screw-shaped structure to produce a spiral flow of the jet flow of gas exiting the outlet; and an internal wall with helical grooves to produce a rifled flow of the jet flow of gas exiting the outlet.
In some embodiments, the connector further includes an inlet channel in fluid communication with the inlet of the gases port, and wherein the at least one flow altering feature is associated with the inlet channel and/or the inlet of the gases port. The at least one flow altering feature may include the inlet channel and/or inlet of the gases port having one or both of: an internal wall with a spiral or screw-shaped structure to produce a spiral flow of the jet flow of gas exiting the outlet; and an internal wall with helical grooves to produce a rifled flow of the jet flow of gas exiting the outlet.
In some embodiments, the at least one characteristic altered includes one or more of: velocity, divergence, spread, profile and/or turbulence of the jet flow of gas exiting the outlet.
In another aspect, a connector for coupling with an invasive respiratory device is disclosed herein, the connector including a main body having: a gases port for receiving a flow of gas from a flow source at a selected flow rate, wherein the gases port includes an inlet and an outlet; an outlet port for outflow of gases from the main body; and a device port couplable with the invasive respiratory device; wherein the connector is configured to receive the flow of gas from the flow source via the inlet of the gases port, and to deliver a jet flow of gas through the outlet of the gases port, wherein the connector further includes a filter couplable with the outlet port for filtering the gases from the main body.
In some embodiments, the gases port further includes a flow constriction for providing the jet flow of gas through the outlet of the gases port. The flow constriction may be disposed between the inlet of the gases port and the device port.
In some embodiments, the filter is non-removable and/or integral with the outlet port. Alternatively, the filter may be removably couplable with the outlet port.
In some embodiments, the connector further includes an inlet channel in fluid communication with the inlet of the gases port, wherein the inlet channel is at least partly surrounded by the filter. The inlet channel may be positioned through a central axis of the filter. The connector may further include an outlet channel in fluid communication with the outlet port, wherein the outlet port is at least partly surrounded by the filter.
In some embodiments, the connector further includes a valve forming the flow constriction, wherein the valve is configured to jet flow of gas towards the device port through an outlet formed upon opening of the valve.
In some embodiments, the filter is one of a radial filter or a receptacle filter.
In another aspect, a connector for coupling with an invasive respiratory device is disclosed herein, the connector including a main body having: a gases port for receiving a flow of gas from a flow source at a selected flow rate, wherein the gases port includes an inlet and an outlet; an outlet port for outflow of gases from the main body; and a device port couplable with the invasive respiratory device; wherein the connector is configured to receive the flow of gas from the flow source via the inlet of the gases port, and to deliver a jet flow of gas through the outlet of the gases port, wherein the outlet of the gases port is offset relative to a central axis of the device port for directing the jet flow of gas along or towards a wall of the main body of the connector and/or a wall of the invasive respiratory device when coupled to the device port.
In some embodiments, the gases port further includes a flow constriction for providing the jet flow of gas through the outlet of the gases port. The flow constriction may be disposed between the inlet of the gases port and the device port.
In some embodiments, the outlet of the gases port is aligned with a wall of the main body of the connector and/or a wall of the invasive respiratory device when coupled to the device port. The outlet of the gases port may be laterally offset relative to the central axis of the device port. The outlet of the gases port may be angularly offset relative to the central axis of the device port.
In some embodiments, the gases port further includes two or more outlets that are offset relative to the central axis of the device port.
In some embodiments, the outlet of the gases port includes an angled opening relative to a transverse axis of the flow constriction for directing the jet flow of gas along or towards a wall of the main body of the connector and/or a wall of the invasive respiratory device when coupled to the device port.
In some embodiments, the connector further includes an inlet channel and an outlet channel in fluid communication with the inlet of the gases port and the outlet port, respectively, wherein the flow constriction is associated with the inlet channel, and wherein a longitudinal axis of the inlet channel and a longitudinal axis of the outlet channel are offset relative to each other.
In some embodiments, the connector further includes including at least one locating feature configured to maintain a desired distance between the outlet of the gases port and a distal end portion of the invasive respiratory device when coupled to the device port. The at least one locating feature may be positioned on the device port and/or the main body of the connector. The at least one locating feature may include an engagement structure for releasably coupling with the invasive respiratory device or an adapter connected to the invasive respiratory device.
In some embodiments, a pressure loss between the outlet of the gases port and the outlet port of the connector is less than about 20 cmH20 at the selected flow rate. Preferably, the pressure loss is less than about 12 cmH20 at the selected flow rate.
In some embodiments of the above connectors disclosed herein or the above insert disclosed herein, the outlet is disposed between the inlet of the gases port and a distal end portion of the invasive respiratory device when coupled to the device port. The outlet may be disposed between the inlet of the gases port and the device port. Preferably, the outlet is disposed between the inlet of the gases port and a distal end portion of the device port.
In some embodiments of the above connectors disclosed herein or the above insert disclosed herein, the flow constriction includes a nozzle having the outlet through which the jet flow of gas is delivered.
In some embodiments of the above connectors disclosed herein or the above insert disclosed herein, the flow constriction includes the outlet having a plurality of apertures through which the jet flow of gas is delivered.
In some embodiments of the above connectors disclosed herein or the above insert disclosed herein, the flow constriction includes a tapered region for constricting the flow of gas prior to exiting the outlet.
In some embodiments of the above connectors disclosed herein or the above insert disclosed herein, the connector may further include one or more gas sampling ports for sampling one or more characteristics of the gases in the main body. The one or more characteristics of the gases may include pressure, flow rate, concentration, gas constituents, temperature, humidity, contaminants, aerosols and/or pathogens. The one or more gas sampling ports may be located on one or both of the outlet port and the main body of the connector.
In some embodiments of the above connectors disclosed herein or the above insert disclosed herein, the flow source is configured to provide a continuous flow of the gas at the selected flow rate. The selected flow rate may include a fixed flow rate or a variable flow rate. The selected flow rate may be in a range of about 10 L/min to about 120 L/min. The selected flow rate may be in a range of about 20 L/min to about 90 L/min. The selected flow rate may be in a range of about 20 L/min to about 70 L/min. The selected flow rate may be in a range of about 40 L/min to about 70 L/min. In other embodiments of the above connectors disclosed herein or the above insert disclosed herein, the selected flow rate is in a range of about 0.5 L/min to about 25 L/min.
In another aspect, a system for providing respiratory support to a subject is disclosed herein, the system including: a flow source for providing a gas at a selected flow rate; an invasive respiratory device couplable with an airway of the subject; and the connector according to any one of the above aspects or embodiments as disclosed herein.
In some embodiments, the system is configured to generate a pressure of at least about 2 cmH2O about the device port when in use. The pressure about the device port may be between about 2 cmH2O and about 20 cmH2O. The pressure about the device port may be between about 2 cmH2O and about 10 cmH2O during inspiration of the subject. Preferably, the pressure about the device port is between about 2 cmH2O and about 5 cmH2O during inspiration of the subject. The pressure about the device port may be between about 5 cmH2O and about 20 cmH2O during expiration of the subject. Preferably, the pressure about the device port is between about 5 cmH2O and about 10 cmH2O during expiration of the subject.
In some embodiments, a pressure loss between the device port and the outlet port of the connector of less than about 20 cmH2O when in use.
In some embodiments, a pressure loss between the outlet of the gases port and the outlet port of the connector is less than about 20 cmH2O when in use. Preferably, the pressure loss between the outlet of the gases port and the outlet port of the connector is less than about 12 cmH2O when in use. A ratio of the pressure about the device port to the pressure loss between the outlet of the gases port and the outlet port may be in a range of more than 0 to about 1:1.
The system may include a pressure loss between the flow source and the outlet port of the connector of less than about 20 cmH2O when in use.
In some embodiments, the flow source is configured to provide a continuous flow of the gas at the selected flow rate. The selected flow rate may include a fixed flow rate or a variable flow rate. The selected flow rate may be in a range of about 10 L/min to about 120 L/min. The selected flow rate may be in a range of about 20 L/min to about 90 L/min. The selected flow rate may be in a range of about 20 L/min to about 70 L/min. The selected flow rate may be in a range of about L/min to about 70 L/min. Alternatively, the selected flow rate may be in a range of about 0.5 L/min to about 25 L/min.
In some embodiments, the system further includes a filter couplable with the outlet port of the connector for filtering the gases from the main body.
In some embodiments, the system further includes an interface conduit connectable between the inlet of the gases port of the connector and the flow source for providing fluid communication. The interface conduit may be configured to heat the gas provided by the flow source to a selected temperature before delivery to the gases port of the connector.
In some embodiments, the system further includes a humidifier configured to condition the gas provided by the flow source to a selected temperature and/or humidity.
In another aspect, a kit for a system for providing respiratory support to a subject is disclosed herein, the kit including: the connector according to any one of the above aspects or embodiments as disclosed herein; and at least one of: a filter couplable with the outlet port of the connector; an invasive respiratory device couplable with the connector; and an adapter connectable to the device port of the connector for coupling an invasive respiratory device with the connector.
In another aspect, a kit for a system for providing respiratory support to a subject is disclosed herein, the kit including: the connector according to any one of the above aspects or embodiments as disclosed herein; and the insert according to the above aspect or any one of the embodiments as disclosed herein.
In some embodiments, the kit further includes at least one of: a filter couplable with the outlet port of the connector; an invasive respiratory device couplable with the connector; and an adapter connectable to the device port of the connector for coupling an invasive respiratory device with the connector.
In some embodiments, the kits above as disclosed herein further include an interface conduit connectable between the inlet of the gases port of the connector and the flow source for providing fluid communication. The interface conduit may be configured to heat the gas provided by the flow source to a selected temperature before delivery to the gases port of the connector.
In some embodiments, the kits above as disclosed herein further include a filter couplable between the inlet of the gases port of the connector and the flow source for filtering the gas provided by the flow source.
In some embodiments, the kits above as disclosed herein further include a humidifier configured to condition the gas provided by the flow source to a selected temperature and/or humidity.
In some embodiments, the kits above as disclosed herein further include a conduit connectable between the flow source and the humidifier, and/or a conduit connectable between the humidifier and the gases port for providing fluid communication.
In some embodiments, the kits above as disclosed herein include the humidifier having a humidification chamber and/or a humidification base unit.
In another aspect, a connector for coupling with an invasive respiratory device is disclosed herein, the connector including a main body having: a gases port for receiving a flow of gas from a flow source at a selected flow rate, wherein the gases port includes an inlet and an outlet; an outlet port for outflow of gases from the main body; a device port couplable with the invasive respiratory device; and a variable aperture for adjusting flow of gases exiting the connector through the outlet port; wherein the connector is configured to receive the flow of gas from the flow source via the inlet of the gases port, and to deliver a jet flow of gas through the outlet of the gases port, and wherein the jet flow of gas delivered through the outlet of the gases port has a velocity in a range of about 5 m/s to about 60 m/s.
In some embodiments, the connector includes a cap applied to or formed over an opening in the outlet port, the cap having a first member with a first opening and a second member with a second opening, wherein relative movement between the first member and the second member varies an amount of overlap between the first and second openings to define the variable aperture. In some embodiments, one of the first member and the second member is stationary in use, and the other of the first member and the second member is movable relative to the stationary member. Preferably, relative movement between the first member and the second member is rotational although that need not be the case and translational or other relative movements may be provided.
In some embodiments, the connector body has a first opening in a wall portion defining the outlet port, and the connector further comprises a movable collar arranged around at least part of the wall portion defining the outlet port, the collar having a second opening, wherein movement of the collar varies an amount of overlap between the first and second openings to define the variable aperture.
In some embodiments, the collar may be rotatable around the wall portion defining the outlet port. In other embodiments, the collar may be translationally moveable along the wall portion defining the outlet port.
In some embodiments, the connector comprises a connector body extension providing the variable aperture.
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.
Embodiments of the invention are generally directed to systems for providing high flow respiratory support to a patient via an invasive respiratory device, such as an endotracheal tube (ETT), a laryngeal mask (LMA) and a tracheostomy tube. The patient may be spontaneously breathing or apnoeic. Embodiments of the invention may be used in medical procedures (e.g., operating theatres), ICUs, wards, emergency departments and the like. Medical procedures should be considered broadly and can include any aspect of providing a medical procedure, including operative procedures, pre, peri and post-operative procedures, and which may or may not include the use of sedation or anaesthesia (more generally called “anaesthetic procedures”).
This respiratory support may provide a continuous flow of gases (unidirectional or positive net flow) towards the patient at high flow rates from a flow source to a spontaneously or non-spontaneously breathing patient via an ETT or other invasive respiratory device. The flow of gases is typically heated and humidified before delivery to the patient. For example, embodiments of the invention can be used during a weaning and extubation process where a patient initially starts breathing, or is attempting to breathe, through an endotracheal tube (ETT). At this point in the procedure, the system can provide a continuous flow of gases to oxygenate, clear CO2 from the patient and/or provide pressure support to the patient. The patient can then more easily be kept in a stable condition while the clinician assesses whether they are ready to be moved to the next part of the transition for spontaneous breathing. Therefore, generation of a pressure at the top of the ETT (proximal to the patient) is potentially beneficial in patient oxygenation and/or CO2 clearance.
The systems according to embodiments described herein may be capable of achieving desirable patient pressures for a given range of flow rates. The systems may generate a range of desirable patient pressures for providing respiratory support that are capable of achieving and/or maintaining desired airway patency for a given range of flow rates, assisting with lung recruitment, preventing or mitigating atelectasis and/or reducing the work of breathing. For spontaneously breathing patients, the flow rates delivered should meet or exceed inspiratory demand and preferably peak inspiratory demand. In certain situations where the patient is spontaneously breathing, the continuous flow of gases provided is independent of the patient's breathing, i.e., the flow of gases does not vary in synchrony with the patient's breathing. High flow respiratory support also involves delivery of respiratory support to oxygenate the patient and provide clearance of carbon dioxide.
According to embodiments of the invention, the system may include a flow source and/or a flow modulator that provides a constant or a varying flow of gases to the patient depending on the therapy, i.e. the selected flow rate that the gases port of the connector receives may be a constant or a varying flow of gases. The constant flow of gases may include a set flow rate. The varying flow of gases may include a base flow rate component and one or more oscillating flow rate components. The base flow rate component may be varying. The oscillating flow rate component may include one or more frequencies. The varying flow of gases may be independent of the patient's breathing. The flow of gases may include a constant flow of gases and a varying flow of gases, for example the flow of gases may be constant for a period of time and may be varying for another period of time. Methods and systems providing a varying flow rate are described in WO 2015/033288, WO 2016/157106 and WO 2017/187390 which are incorporated herein by reference.
Embodiments of the invention aim to effectively deliver high flow respiratory support invasively by employing a system that includes a connector configured to produce a jet flow of gas into an invasive respiratory device (such as an ETT) coupled to the connector. The system delivers inspiratory flow from a flow source, optionally via a humidifier, to the connector. The connector is configured to receive the inspiratory flow, and to deliver a jet flow of gas through an outlet of the connector and towards the invasive respiratory device and patient. An inspiratory flow path enables delivery of the inspiratory flow which is jetted through the outlet of the connector towards the invasive respiratory device and patient. Thus, inspiratory flow in this context refers to the gases which are delivered towards and/or to the patient regardless of whether the patient is breathing or apnoeic. In some embodiments, the connector includes a flow constriction for providing the jet flow of gas through the outlet of the connector. The flow constriction is preferably disposed in the inspiratory flow path to provide the jet flow of gas towards the ETT and patient. The flow constriction may include, for example, a nozzle, a tapered region for constricting the flow of gas, and/or a plurality of apertures or openings through which the jet flow of gas is delivered.
An expiratory flow path enables outflow of gases to exit through an outlet port of the connector. In some embodiments, the outlet port enables the outflow of gases to vent to atmosphere, and may include a filter. Alternatively, the outlet port may be couplable with an expiratory conduit for directing the outflow of gases to a respiratory support apparatus, such as a ventilator or anaesthesia machine. The expiratory flow in the expiratory flow path may include expiratory gases from the patient or a small amount of gases from the patient following gas exchange, both of which are returned through the invasive respiratory device and exit the outlet port. The expiratory flow may also include excess inspiratory flow, namely jetted gas flow being delivered to the patient which also exits through the outlet port. If the patient is breathing, the expiratory flow in the expiratory flow path may include expiratory gases from the patient and excess inspiratory flow. Otherwise, if the patient is apnoeic, the expiratory flow in the expiratory flow path may include excess inspiratory flow and/or a small amount of other gases from the patient following gas exchange. Thus, expiratory flow in this context refers to the gases which are returned from the patient and/or invasive respiratory device, including excess inspiratory flow, which exits through the outlet port regardless of whether the patient is breathing or apnoeic.
In this specification, invasive respiratory devices could include any device or instrument that is couplable with an airway of the subject, usually bypassing the subject's upper respiratory tract or lower respiratory airway. Invasive respiratory devices may include any device or instrument that is couplable with the lower respiratory tract or lower respiratory airway of the subject. Invasive respiratory devices include but are not limited to devices and instruments that penetrate via a patient's mouth, nose or skin to serve as an artificial airway, such as an endotracheal tube, tracheostomy tube, laryngeal mask, suspension laryngoscope, or endoscope, to name a few. It will be appreciated that these are examples only, and that the embodiments of the invention are not limited to use with endotracheal tubes or particular invasive respiratory devices described herein, and may employ other respiratory devices as would be known to a person skilled in the art.
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, the terms “distal” and “proximal” are to be interpreted relative to the subject or patient. Distal refers to a feature being directed away from or further from the subject or patient. Proximal refers to a feature being directed towards or close to the subject or patient.
In this specification, the gas delivered by a flow source could include, without limitation, oxygen, carbon dioxide, nitrogen, helium, and anaesthetic agents, to name a few, or mixtures of these or other breathable gases for respiration and/or ventilation. Where reference is made to a particular gas herein, it will be appreciated that it is by way of example only and the description can apply to any gas—not just that referenced.
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.
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 happening at the entrance of the patient's airways, which is the entrance of the invasive respiratory device when the patient is intubated, the invasive respiratory device providing an artificial airway to the patient. 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, 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, 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 or provided to a connector of embodiments of the invention via a system or from a flow source, 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).
In configurations where the system provides a varying flow of gases comprising a base flow rate component and one or more oscillating flow rate components, the base flow rate component includes 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 or provided to a connector of embodiments of the invention via a system or from a flow source, may include, but is not limited to, flows of at least about 5, 10, 15, 20, 30, 40, 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). The oscillating flow rate component includes a flow rate of about 0.05 litres/min per patient kilogram to about 0.5 litres/min per patient kilogram; and preferably about 0.12 litres/min per patient kilogram to about 0.4 litres/min per patient kilogram; and more preferably about 0.12 litres/min per patient kilogram to about 0.35 litres/min per patient kilogram.
In “high flow” the gas delivered will be chosen depending on for example the intended use of a therapy. 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 L/min/kg to about 8 L/min/kg with a minimum of about 0.5 L/min and a maximum of about 25 L/min. For patients under 2 kg maximum flow is set to 8 L/min. In configurations where the system provides a varying flow of gases including a base flow rate component and one or more oscillating flow rate components, the flow rate of the base flow rate component can be set to about 0.4 L/min/kg to about 8 L/min/kg with a minimum of about 0.5 L/min and a maximum of about 25 L/min, and the maximum flow is set to 8 L/min for patients under 2 kg. The flow rate of the oscillating flow rate component can be set to about 0.05 L/min/kg to about 2 L/min/kg with a preferred range of about 0.1 L/min/kg to about 1 L/min/kg and another preferred range of about 0.2 L/min/kg to about 0.8 L/min/kg.
Additionally in the context of high flow support being delivered invasively, this may generate a flushing effect in the lower trachea and bronchioles such that the anatomic dead space of the upper and/or lower 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.
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 increased 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. When humidified, the high gas flow can also prevent airways from drying out, mitigating mucociliary damage, and risks associated with airway drying, and airway obstruction, swelling and bleeding.
Embodiments of the invention are directed to systems for providing high flow respiratory support being invasively delivered to a patient. Certain embodiments may achieve certain advantageous outcomes by use of an inventive connector configured to deliver a jet flow of gas into the invasive respiratory device (such as an ETT).
For simplicity, the same reference numerals have been used throughout this specification for the systems 100 according to the inventive aspects as disclosed herein, and the connectors 200 according to the inventive aspects of the invention as disclosed herein. Thus the systems 100 and connectors 200 may encompass one or more of the inventive aspects, as described in relation to the embodiments of the invention. Furthermore, it is intended that features of the systems 100 and the connectors 200 sharing the same reference numerals correspond to the same features as described in connection with embodiments of the invention.
Embodiments of the invention may provide systems that include at least one of three inventive aspects described below, although combinations of two or more of the inventive aspects is desirable. Embodiments of the invention may provide systems that include one or more of the three inventive aspects in combination with any combinations of embodiments of the inventive systems as disclosed herein. Embodiments of the invention may provide systems including an inventive connector according to any one of the aspects of the invention as disclosed herein, or combinations thereof, and/or any combinations of embodiments of the inventive connectors as disclosed herein. Embodiments of the invention may also provide connectors that include any one of the aspects of the invention as disclosed herein, or combinations thereof, and/or any combinations of embodiments of the inventive connectors as disclosed herein.
Embodiments of the invention are directed to a system configured to provide respiratory support to a subject by generating a pressure within a range of desirable patient pressures for a given range of flow rates. Desirable patient pressures for providing respiratory support may include a pressure or a range of pressures that are capable of achieving and/or maintaining a patent patient airway, assisting with lung recruitment, preventing or mitigating atelectasis and/or reducing the work of breathing. The inventors have found that the lowest value of patient pressure acceptable for providing respiratory support is about 2 cmH2O.
In a first inventive aspect, there is provided a system 100 for providing respiratory support to a subject 300, as illustrated in
The inventors have found that there is minimal pressure loss between the device port 240 of the connector 200 and a proximal end portion 124 of the invasive respiratory device 200 to be located in the airway of the subject 300 (see
The inventors have also found that the highest desirable pressure about the device port 240 is about 20 cmH2O. Above 20 cmH2O, there could be a risk of barotrauma to the subject 300. As such, embodiments of the system 100 may be configured to generate a pressure of between about 2 cmH2O and about 20 cmH2O.
Furthermore, the system 100 aims to provide a target patient pressure during inspiration of between about 2 cmH2O and about 10 cmH2O. Preferably, the target patient pressure during inspiration is between about 2 cmH2O and about 5 cmH2O. The system 100 also aims to provide a target patient pressure during expiration of between about 5 cmH2O and about 20 cmH2O. Preferably, the target pressure during expiration is between about 5 cmH2O and about 10 cmH2O.
Thus, embodiments of the system 100 may be configured to generate a pressure of between about 2 cmH2O and about 10 cmH2O during inspiration of the subject 300, preferably between about 2 cmH2O and about 5 cmH2O during inspiration, and a pressure of about 5 cmH2O and about 20 cmH2O during expiration of the subject 300, preferably between about 5 cmH2O and about 10 cmH2O during expiration.
In some embodiments, the system 100 is configured to provide respiratory support to a subject 300 by having a low resistance to expiratory flow. This involves the system 100 having an expiratory resistance to flow (RTF) of less than about 20 cmH2O to a gases flow from the device port 240 to the outlet port 230. In some embodiments, the system 100 provides an expiratory RTF of less than about 20 cmH2O to an expiratory flow from the device port 240 to the outlet port 230 during an expiratory phase of a spontaneously breathing patient.
In another inventive aspect, there is provided a system 100 for providing respiratory support to a subject 300 as illustrated in
The pressure loss corresponds to the expiratory resistance to flow (RTF) of the connector 200 in the system 100. This is the pressure loss across the expiratory flow path 270, which is defined between the device port 240 and the outlet port 230 of the connector 200 (see also
A connector 200 having a lower RTF results in less pressure loss in the system 100, increasing efficiency, and also requires less driving pressure generated by the system 100, which is discussed below. Furthermore, a lower expiratory RTF also decreases the work of breathing for the subject 300 by decreasing the lung pressure excursion required to maintain a given minute volume (i.e., flow). Some of the beneficial effects of lower RTF can be observed in relation to Example 4 and the chart of
In some embodiments, the system 100 is configured to provide respiratory support to a subject 300 by having a low driving pressure. The driving pressure is the pressure required to drive a desired flow of gas through the system 100 and preferably, to achieve a desired patient pressure and/or flow rate.
In another inventive aspect, there is provided a system 100 for providing respiratory support to a subject 300 as illustrated in
The driving pressure corresponds to the pressure loss in the system 100. The driving pressure may include the pressure loss across the connector 200, that is the pressure loss between the outlet 260 of the gases port 220 and the outlet port 230. The pressure loss between the outlet 260 of the gases port 220 and the outlet port 230 may be less than about 20 cmH2O when in use. Preferably, the pressure loss is less than about 12 cmH2O when in use. The driving pressure may also include a pressure loss between the flow source 110 and the outlet port 230 of the connector 200. In that case, the pressure loss between the flow source 110 and the outlet port 230 of the connector 200 is preferably less than about 20 cmH2O.
A lower driving pressure is desirable as the system 100 can achieve the desired patient pressures as described above with lower performance. This has an impact on the complexity of the system 100 as well as potentially the system portability. A system 100 with a lower driving pressure also has a lower risk of barotrauma for the patient 300.
In some embodiments of the above systems according to aspects of the invention, a ratio of the pressure about the device port 240 to the pressure loss between the outlet 260 of the gases port 220 and the outlet port 230 is in a range of more than 0 to about 1:1. Preferably, the ratio is in a range of about 0.3:1 to about 1:1. More preferably, the ratio is in a range of about 0.6:1 to about 1:1. The ratio may be, for example, in a range of about 0.1:1 to about 1:1, about 0.2:1 to about 1:1, about to about 1:1, about 0.4:1 to about 1:1, about 0.5:1 to about 1:1, about 0.6:1 to about 1:1, about 0.7:1 to about 1:1, about 0.8:1 to about 1:1, about 0.9:1 to about 1:1, or may be about 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1 or 1:1. Ideally, the ratio is about 1:1 which represents minimal pressure loss in the system 100 such that the system 100 can be driven at a lower pressure to achieve the desired patient pressures, which preferably reduces the risk of barotrauma for the patient 300.
The system 100 of
In some embodiments, the flow source 110 is configured to provide a continuous flow of gas at the selected flow rate. The continuous flow may be a unidirectional or positive net flow towards the patient at high flow rates. Furthermore, the selected flow rate for the flow source 110 may be a fixed flow rate or a variable (or varying) flow rate. The fixed or variable (varying) flow rate may be independent of the respiratory cycle of the patient 300. The variable or varying flow rates may be in the range of those defined previously in the Overview.
The gas flow is delivered from the flow source 110 to a conduit 130 connectable between the flow source 110 and a humidifier 140. In the exemplary system 100 as shown, the humidifier 140 includes a humidification chamber 142 and a humidification base unit 150. The conduit 130 may include a dry line for delivering dry flow of gases to the humidifier 140. The conduit 130 may be coupled to the humidification chamber 142 of the humidifier 140 as shown. In alternative embodiments, the humidifier 140 may be a single component and exclude the separate humidification chamber 142 and base unit 150 (not shown). The humidifier 140 may be configured to condition the gas provided by the flow source 110 to a selected temperature and/or humidity, for example, within the humidification chamber 142 as shown. The temperature and/or humidity selected may be dependent on the therapy being delivered and is selected to be suitable for the respiratory support to be provided, which may be tailored for human or animal subjects. A user or operator may select the desired temperature and/or humidity. Additionally/alternatively, the humidifier 140 may be configured to select the desired temperature and/or humidity by identifying a specific conduit 130 in use, e.g., by use of a sensor such as a resistor on the conduit 130.
The conditioned gas flow proceeds from the humidifier 140 (or more specifically the humidification chamber 142 as shown) through an inspiratory conduit 160 connectable between the humidifier 140 and an inlet 216 of a gases port 220 of the connector 200 for providing fluid communication (see
The system 100 includes an optional filter 170. The filter 170 may be positioned between the inspiratory conduit 160 and the patient interface conduit 180. Gases flowing through the inspiratory conduit 160 are passed to the patient by way of the optional filter 170, the connector 200 and the invasive respiratory device 120. The interface conduit 180 is connectable between the inlet 216 of the gases port 220 of the connector 200 and the flow source 110 for providing fluid communication. The interface conduit 180 may be located in the system 100 between the conduit 160 and/or filter 170 and the connector 200.
A filter 190 may also be optionally provided in the expiratory flow path 270 (see also
In some embodiments, the filters 170 and 190 may be non-removable and/or integral with conduit 160 and connector 200, respectively. Alternatively, the filters 170 and 190 may be releasably couplable with the conduit 160 and connector 200, respectively. The filter 190 may include a radial filter, or a receptable or bag filter, as will be described in connection with
The inspiratory conduit 160 and patient interface conduit 180 may be one or more of corrugated, flexible, bendable, resistant to kink and/or heated (e.g., the conduits 160, 180 may include a heating element). In some embodiments, the inspiratory conduit 160 and/or the patient interface conduit 180 is configured to heat the gas provided by the flow source 110 to a selected temperature before delivery to the gases port 220 of the connector 200. In this embodiment, the inspiratory conduit 160 and/or the patient interface conduit 180 may include a heating element such as a heating wire. The temperature may be dependent on the therapy being delivered and is selected to be suitable for the respiratory support to be provided, which may be tailored for human or animal subjects. A user or operator may select the desired temperature. Additionally/alternatively, the conduit 180 may be a breathable tube, such as described in U.S. Pat. No. 7,493,902 which is incorporated herein by reference.
In the connector 200 as shown in
A jet flow of gas is a region of high velocity of gas. The jet flow of gas preferably includes a velocity that is capable of achieving one or more of the system objectives described above. The jet flow of gas preferably includes a velocity that is capable of achieving at least the target patient pressure of at least 2 cmH2O about the device port 240 when in use. The velocity of the jet flow of gas may be greater or less than the velocity of a gases flow provided or generated by a flow source 110. Preferably, the velocity of the jet flow of gas is greater than the velocity of a gases flow provided or generated by a flow source 110. Additionally or alternatively, the velocity of the jet flow of gas may be greater or less than the velocity of a gases flow elsewhere in the system 100, preferably the velocity of the jet flow of gas is greater than the velocity of a gases flow elsewhere in the system 100. Preferably, the jet flow of gas includes a velocity in a range of about 5 m/s to about 60 m/s, as will be discussed below. Preferably, the jet flow of gas includes a velocity in a range of about m/s to about 60 m/s at a selected flow rate of about 20 L/min to about 70 L/min of the flow of gas provided by the flow source 110. The jet flow of gas may include a velocity in a range of about 5 m/s to about 60 m/s at a selected flow rate of about 20 L/min to about 90 L/min of the flow of gas provided by the flow source 110.
In this embodiment, it is noted that the outlet 260 of the gases port 220 is disposed between the inlet 216 of the gases port 220 and the device port 240. As shown in other embodiments, for example in
In the connectors 200 of
In some embodiments as shown, the flow constriction 250 includes a tapered region or portion for constricting flow of gas prior to exiting the outlet 260. The flow constriction 250 of
An angle of the wall 224 of the tapered region relative to the longitudinal axis 252 of the flow constriction 250 may be in a range of more than 0 degrees to about 45 degrees. Preferably, the angle is between about 2 degrees and about 20 degrees. The angle of the taper may be, for example, between about 2 degrees and about 15 degrees, about 5 degrees and about 20 degrees, about 5 degrees and about 15 degrees, about 10 degrees and about 15 degrees, about 10 degrees and about 20 degrees, and may be about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 degrees. The angle of the wall 224 represents the half angles of the tapered region relative to the longitudinal axis 252 which provide an efficient means of constricting the flow.
A jet flow of the gas exits the outlet 260 of the flow constriction 250, which in this embodiment is adjacent to the device port 240 for coupling to the invasive respiratory device 120. Since the gases port 220, flow constriction 250 and device port 240 are coaxial in this embodiment, along axis 252, the jet flow of the gas is delivered centrally into the invasive respiratory device 120 when coupled to the device port 240, such as via the adapter 126 shown in
During patient expiration, the majority of gases from the jet vent out of the connector 200 through an outlet port 230. That is, the direction of travel of gases is along an expiratory flow path 270 defined between the device port 240 and the outlet port 230 (see also
It is important to note that a jet of gases is provided by the flow constriction 250 of the connector 200 of various embodiments of the invention, and the flow constriction 250 is not located within the invasive respiratory device 120 (or within a device or instrument in the patient's airway). The location of formation of the jet of gases within the connector 200 rather than the invasive respiratory device 120 reduces the probability of barotrauma occurring in the lung through a blockage of the trachea, and is an important advantage of various embodiments of the invention.
In the embodiments of
In this embodiment, the outlet port 230 is shown as a plurality of openings or apertures 263 for passage of gas flow in the expiratory flow path 270 to the atmosphere. Although the embodiment illustrates six apertures or openings 263, the connector 200 may include any number of apertures or openings for passage of gas flow in the expiratory flow path 270 out of the connector 200, as would be appreciated by a person skilled in the art. Furthermore, the number, size and shape of the apertures may be configured in order to alter the resistance to flow (RTF) of the connector 200.
The connector 200 includes a gases port 220 having an inlet 216 in flow communication with an inlet channel 222, a flow constriction 250 and an outlet 260. In this embodiment, the flow constriction 250 is in the form of a tapered nozzle extending into the main body 210 of the connector 200. However, embodiments of the invention are not limited to a tapered nozzle and may instead include a plurality of openings or apertures 261 as shown in the embodiments of
In relation to
It may be desirable that the tapered nozzle directs inspiratory flow to a wall 212 of the connector 200 before the jet flow proceeds to the invasive respiratory device 120 (e.g., an ETT) coupled in use with the system 100. A jet of gases ‘attaching’ to a wall 212, 244 of the connector 200 and/or a wall 128 of the invasive respiratory device 120 (see also
If flow is directed and jetted centrally down the invasive respiratory device 120, inspiratory/expiratory flow can coincide causing turbulent/pressure losses and increasing RTF (see also
Flow attachment occurs when flow of gas attaches to a wall(s) of the connector 200 and/or the invasive respiratory device 120. Flow attachment can be beneficial across all patients 300 (spontaneously and non-spontaneously breathing) as generating a desired patient pressure is important for oxygenation and airway CO2 clearance. Furthermore, flow attachment may be especially beneficial to spontaneously breathing patients where a reduced expiratory resistance (i.e., reduced expiratory RTF of the connector 200) reduces the work of breathing of a patient 300.
In some embodiments, the connector 200 may include one or more gas sampling ports 214 located on the main body 210, such as for sampling pressure levels of the gases in the main body 210. As shown in
In some embodiments, the connector 200 may also include a suctioning port (not shown). The suctioning port may be located in the same or similar positions on the connector main body 210 or outlet port 230 of the connector 200 as the gas sampling ports 214, 234. The suctioning port may provide for removal of bodily fluids from the connector 200, such as mucus.
Various parameters of inventive connectors 200 according to embodiments of the invention will now be described in connection with
In this embodiment, the offset of the outlet channel 232 relative to the inlet channel 222 is at an acute angle such that the outlet port 230 and the gases port 220 are adjacent. This is more clearly shown in
The flow constriction 250 is provided in the form of a tapered nozzle with walls 224 of the tapered region as illustrated in
Advantageously, the conditioning portion 254, which may include a substantially constant diameter and/or cross-sectional area, may condition the flow such that it is directed in a desired direction towards or along a wall 212 of the main body 210 of the connector or towards or along a wall 128 of the invasive respiratory device 120 when in use. Furthermore, a constant diameter portion 254 may reduce pressure dissipation out of the outlet 260 when compared with a jet outlet 260 that immediately follows the tapered region of the flow constriction 250.
The advantages of the conditioning portion 254 may be appreciated with respect to the embodiments illustrated in
Similarly,
The inventors have determined parameters of the connector 200 that influence performance with respect in particular to the system objectives described herein. There are some trade-offs when optimising the connector parameters to meet certain objectives as would be understood by a person skilled in the art. In particular, there is a desired minimum patient pressure and a range of flows that can be provided which meets this minimum pressure (where the flow meets the patient inspired flow in a spontaneous breathing situation). Losses in generated pressure depend on the rate of energy dissipation in the fluid leaving the nozzle which depends on some of these parameters.
Connector with Jet Flow Velocity
In another inventive aspect, there is provided a connector 200 for coupling with an invasive respiratory device 120. The connector 200 includes a main body 210 having a gases port 220 for receiving a flow of gas from a flow source 110 at a selected flow rate, an outlet port 230 for outflow of gases from the main body 210, and a device port 240 couplable with the invasive respiratory device 120. The gases port 220 includes an inlet 216 and an outlet 260. The connector 200 is configured to receive the flow of gas from the flow source 110 via the inlet 216 of the gases port 220, and to deliver a jet flow of gas through the outlet 260 of the gases port 220. The jet flow of gas delivered through the outlet 260 of the gases port 220 has a velocity in a range of about 5 m/s to about 60 m/s.
Preferably, the jet flow of gas includes a velocity in a range of about 5 m/s to about 60 m/s at a selected flow rate of about 20 L/min to about 70 L/min of the flow of gas provided by the flow source 110. The jet flow of gas may include a velocity in a range of about 5 m/s to about 60 m/s at a selected flow rate of about 20 L/min to about 90 L/min of the flow of gas provided by the flow source 110.
The diameter or cross-sectional area A of the jet outlet 260 is one of the main factors that controls RTF and flow penetration down the invasive respiratory device 120 (e.g., an ETT). The smaller the jet diameter, the higher the jet velocity for a given flow and therefore, the higher the static pressure generated at the ETT entrance for a given flow. However, frictional and turbulent losses will increase as the jet diameter decreases. Thus, higher pressures are required to drive the same flow through the system 100 for smaller jet diameters and a higher driving pressure is necessary to generate the same pressure in the ETT.
The inventors have found that by optimising the parameter representing the outlet diameter and/or cross-sectional area A of the flow constriction 250, they are able to achieve a velocity of about 5 m/s to about 60 m/s of the jet flow exiting the outlet 260. The velocity may be, for example, in a range of about 5 m/s to about 50 m/s, about 10 m/s to about 50 m/s, about 10 m/s to about 40 m/s, about 20 m/s to about 40 m/s, about 30 m/s to about 50 m/s, about 30 m/s to about 40 m/s, and may be about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60 m/s.
This velocity may be achieved by the outlet 260 having a hydraulic diameter in a range of about 2 mm to about 10 mm. Preferably, the hydraulic diameter is in a range of about 5 mm to about 8 mm, preferably for embodiments where the outlet 260 has a circular cross-section. The hydraulic diameter of the outlet 260 may be, for example, in the range of about 3 mm to about 9 mm, about 4 mm to about 8 mm, about 5 mm to about 7 mm, and may be about 2, 3, 4, 5, 6, 7, 8, 9 or 10 mm, or about 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5 or 9.5 mm.
Furthermore, the outlet 260 may have a cross-sectional area (CSA) in a range of about 10 mm2 to about 60 mm2. Preferably, the cross-sectional area is in a range of about 19 mm2 to about 50 mm2 (based on the circular cross-section with diameter 5-8 mm2). The CSA of the outlet 260 may be, for example, in a range of about 10 mm2 to about 50 mm2, about 20 mm2 to about 50 mm2, about 25 mm2 to about 45 mm2, about 30 mm2 to about 40 mm2, about 35 mm2 to about 45 mm2, and may be about 10, 15, 19, 20, 25, 30, 35, 40, 45 or 50 mm2.
The hydraulic diameter, DH, of the outlet 260 may be defined as follows:
where
The distance B of the jet nozzle outlet 260 from the invasive respiratory device 120 is another important parameter. This distance B is a determinant of the generated patient pressure. In some embodiments, a distance B from the outlet 260 to a distal end portion 122 of the invasive respiratory device 120 when coupled to the device port 240 is in a range of about 0 mm to about 60 mm. Preferably, the distance B is in a range of about 10 mm to about 30 mm.
An outlet 260 which is too close to the invasive respiratory device 120 can increase the expiratory resistance to flow (RTF) of the connector 200. If the patient 300 is spontaneously breathing, this will increase the work of breathing and the lung pressure excursion required to maintain a given per minute volume (flow). Thus, there is a balance required and optimal jet diameter range and distance from invasive respiratory device 120. This balance can be shown in terms of a ratio between jet area to distance from the ETT. In some embodiments, a ratio of the cross-sectional area of the outlet 260 of the gases port 220 to the distance from the outlet 260 of the gases port 220 to the distal end portion 122 of the invasive respiratory device 120 is between about 1:1 and about 1:10. More preferably, the ratio is between about 1:1 and about 1:5. The ratio may be, for example, between about 1:1 and about 1:9, between about 1:2 and about 1:8, between about 1:3 and about 1:7, between about 1:4 and about 1:6, or may be about 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10.
In some embodiments, the adapter 126 of the invasive respiratory device 120 and/or the connector 200 may include a stop or locating feature to maintain a desired distance B between the outlet 260 and a distal end portion 122 of the invasive respiratory device 120 when coupled to the device port 240 (see
The at least one locating feature may include an engagement structure for releasably coupling the device port 240 or main body 210 of the connector 200 with the invasive respiratory device 120 or an adapter 126 connected to the invasive respiratory device 120. The engagement structure may include one or more of a protrusion, a rib, a groove and a flange on an internal or external surface or wall of the device port 240 or main body 210.
Returning to the embodiments of
Connector with Minimum Expiratory Path Area
In another inventive aspect, there is provided a connector 200 for coupling with an invasive respiratory device 120. The connector 200 includes a main body 210 having a gases port 220 for receiving a flow of gas from a flow source 110 at a selected flow rate, an outlet port 230 for outflow of gases from the main body 210, and a device port 240 couplable with the invasive respiratory device 120. The gases port 220 includes an inlet 216 and an outlet 260. The connector 200 is configured to receive the flow of gas from the flow source 110 via the inlet 216 of the gases port 220, and to deliver a jet flow of gas through the outlet 260 of the gases port 220. The connector 200 further includes an expiratory flow path 270 defined between the device port 240 and the outlet port 230. The expiratory flow path 270 has a minimum cross-sectional area of at least about 25 mm2.
The inventors have found that a minimum opening or cross-sectional area C of the expiratory flow path 270, as illustrated in
In the embodiments described herein, such as with reference to
The jet of gases exiting the outlet 260 in the inspiratory flow path 280 aims to generate a desired patient pressure to maintain airway patency. The CSA of the expiratory flow path 270, defined between the device port 240 and the outlet port 230, can be tuned to achieve desired results in terms of patient pressures, RTF and driving pressure. An exemplary method of tuning the connector 200 for desired results in terms patient pressures, RTF and/or driving pressure includes providing a gases flow at a set flow rate through the connector 200 and altering the CSA of the expiratory flow path 270 until the desired results are achieved. This method can be used to tune the other features (e.g. shape and/or size of the outlet 260, distance of the outlet 260 to the distal end portion 122 of the invasive respiratory device 120, etc.) of the connector 200 as disclosed the specification herein. A minimum CSA for the expiratory flow path 270 aims to limit the pressure that the patient 300 experiences during expiration and work required for exhalation. Accordingly, it is desirable that a minimum CSA of the expiratory flow path 270 is greater than a CSA of the jet outlet 260. The CSA of the expiratory flow path 270 being greater than the CSA of the jet outlet 260 may desirably provide a lower expiratory RTF and resistance to expiration for the subject 300.
In some embodiments, a ratio of the minimum cross-sectional area C of the expiratory flow path 270 to the CSA of the outlet 260 of the gases port 220 may be between about 2:1 and about 3:1. In some embodiments, the ratio may be between about 2.5:1 and about 3:1, between about 2:1 and about 2.5:1, and the ratio may be about 2:1, 2.5:1 or 3:1. The minimum CSA of the expiratory flow path 270 may be located at any point along the path 270, such as along the outlet channel 232, at the outlet port 230, or preferably, at the entrance of the expiratory flow to the outlet channel 232, which is shown adjacent the outlet 260 as illustrated in
As illustrated with reference to
Connector with Integrally Formed Flow Constriction
As shown in
Connector with Nozzle Insert
In another inventive aspect, there is provided a connector 200 for coupling with an invasive respiratory device 120. The connector 200 includes a main body 210 having a gases port 220 having an inlet 216 for receiving a flow of gas from a flow source 110 at a selected flow rate, an outlet port 230 for outflow of gases from the main body 210, and a device port 240 couplable with the invasive respiratory device 120. The connector 200 further includes an inlet channel 222 in flow communication with the inlet 216 of the gases port 220. The connector 200 is configured to receive an insert 400 positionable within the inlet channel 222 for providing an outlet 260. The connector 200 is configured to receive the flow of gas from the flow source 110 via the inlet 216 of the gases port 220, and to deliver a jet flow of gas through the outlet 260 provided by the insert 400.
As referred to previously,
In particular, the insert 400 of this embodiment is best shown in
The locating feature of the connector 200 can also assist with the insert 400 and the jet nozzle 260 being maintained at a known desired distance B from a distal end portion 122 of the invasive respiratory device 120. As previously described, the distance B of the jet outlet 260 from the distal end portion 122 of the invasive respiratory device 120 is an important parameter and should be maintained in a desired range. A user or operator may select or be able to manually adjust the distance B by selecting or adjusting a desired length of the insert 400 located within the inlet channel 222. Alternatively, separate inserts 400 with different lengths may be provided to achieve different distances from the distal end portion 122 of the invasive respiratory device 120.
The insert 400 also includes at least one locating feature to guide positioning within the inlet channel 222. The locating feature may include the region of reduced cross-sectional area having the opening 410 of the insert 400 as shown in
In another inventive aspect, there is provided an insert 400 for a connector 200 couplable with an invasive respiratory device 120. The connector 200 includes a main body 210 having a gases port 220 including an inlet 216 for receiving a flow of gas from a flow source 110 at a selected flow rate, an outlet port 230 for outflow of gases from the main body 210, and a device port 240 couplable with the invasive respiratory device 120. The connector 200 further includes an inlet channel 222 in fluid communication with the inlet 216 of the gases port 220. The insert 400 is configured to be positioned in the inlet channel 222 of the connector 200 to provide an outlet 260. The connector is configured to receive the flow of gas from the flow source 110 via the inlet 216 of the gases port 220, and to deliver a jet flow of gas through the outlet 260 provided by the insert 400.
The insert 400 may include one or more of the features as described in connection embodiments of the invention of the connector 200 having insert 400 shown in
Connector with Nozzle Outlet Offset
In previous embodiments described, the outlet 260 of the connector 200 has often been coaxial with the device port 240 and invasive respiratory device 120 when coupled thereto. This is illustrated in
In the embodiments shown in
In another inventive aspect, there is provided a connector 200 for coupling with an invasive respiratory device 120. The connector 200 includes a main body 210 having a gases port 220 for receiving a flow of gas from a flow source 110 at a selected flow rate, an outlet port 230 for outflow of gases from the main body 210, and a device port 240 couplable with the invasive respiratory device 200. The gases port 220 includes an inlet 216 and an outlet 260. The connector 200 is configured to receive the flow of gas from the flow source 110 via the inlet 216 of the gases port 220, and to deliver a jet flow of gas through the outlet 260 of the gases port 220. The outlet 260 of the gases port 220 is offset relative to a central axis 246 of the device port 240 for directing the jet flow of gas along or towards a wall 212 of the main body 210 of the connector 200 and/or a wall 128 of the invasive respiratory device 120 when coupled to the device port 240 (see
In some embodiments, the outlet 260 may be substantially aligned with or directed towards a wall 212 of the main body of the connector 200 and/or a wall 128 of the invasive respiratory device 120 coupled to the device port 240. These embodiments will be described in relation to
In
As shown in
The previous connector embodiments show the longitudinal axis 228 through the gases port 220 as being aligned with the direction of flow through the invasive respiratory device 120. However, in some embodiments, the outlet 260 is angularly offset relative to the central axis 246 of the device port 240. This is shown in the embodiments of
In some embodiments, the outlet 260 may include an angled opening relative to a transverse axis 256 of the flow constriction 250 for directing the jet flow of the gas along or towards a wall 212 of the main body 210 of the connector 200 and/or a wall 128 of the invasive respiratory device 120 when coupled to the device port 240. Effectively, the jet nozzle outlet 260 may be ‘cut off’ at an angle relative to the transverse axis 256 of the flow constriction 250 to direct flow out of the outlet 260 in a desired direction, e.g., along or towards walls of the main body 210 or invasive respiratory device 120. An exemplary embodiment of a nozzle with an angled or “cut off” outlet 260 is shown in
Connector with Fluidic Switch Mechanism
According to another inventive aspect, there is provided a connector 200 for coupling with an invasive respiratory device 120. The connector 200 includes a main body 210 having a gases port 220 for receiving a flow of gas from a flow source 110 at a selected flow rate, an outlet port 230 for outflow of gases from the main body 210, and a device port 240 couplable with the invasive respiratory device 200. The gases port 220 includes an inlet 216 and an outlet 260. The connector 200 is configured to receive the flow of gas from the flow source 110 via the inlet 216 of the gases port 220, and to deliver a jet flow of gas through the outlet 260 of the gases port 220. The connector 200 is configured to change the direction of gas flow within the main body 210 of the connector 200 when in use.
More specifically, the connectors 200 of
In the embodiments shown in
In relation to
In these embodiments, the opposing wall 215 forms at least part of a wall 238 of the outlet port 230. However, embodiments of the invention are not limited to this arrangement and the opposing wall 215 may be located on a section of the main body 210 of the connector 200 at a distance from the outlet port 230. Additionally, in some embodiments, such as illustrated in
Connector with Flow Altering Feature
According to another inventive aspect, there is provided a connector 200 for coupling with an invasive respiratory device 120. The connector 200 includes a main body 210 having a gases port 220 for receiving a flow of gas from a flow source 110 at a selected flow rate, an outlet port 230 for outflow of gases from the main body 210, and a device port 240 couplable with the invasive respiratory device 200. The gases port 220 includes an inlet 216 and an outlet 260. The connector 200 is configured to receive the flow of gas from the flow source 110 via the inlet 216 of the gases port 220, and to deliver a jet flow of gas through the outlet 260 of the gases port 220. The connector 200 further includes at least one flow altering feature for altering at least one characteristic of the jet flow of gas exiting the outlet 260.
The connector 200 may have a flow altering feature associated with the flow constriction 250, the outlet 260, the inlet 216 of the gases port 220 and/or the inlet channel 222. The flow altering feature may be configured to create or increase a degree of turbulent or chaotic flow of the jet flow of gas exiting the outlet 260, as will be described. The characteristics altered may include, for example, one or more of direction, velocity, divergence, spread, profile and/or turbulence (e.g., Reynolds number) of the jet flow exiting the outlet 260. For a selected flow rate, the presence of a flow altering structure may alter or change these characteristics of the flow jetting out of the outlet 260 to achieve desirable characteristics based on the intended respiratory support being provided.
For example, the presence of a flow altering structure may alter flow characteristics such that desirable respiratory support can be achieved with a larger jet outlet diameter A, potentially reducing the necessary driving pressure in the system 100 whilst maintaining the RTF of the connector 200 and the patient pressure. Additionally or alternatively, these structures may create a spiralled or chaotic flow in the invasive respiratory device 120, which can have benefits as discussed below.
Referring to
Connector with Coaxial Flow Paths
In some embodiments, the connector 200 is provided with coaxial inspiratory and expiratory flow paths 280, 270 as shown in the exemplary connector 200 of
In
Connector with Flow Around Nozzle
In some embodiments, the flow constriction 250 is formed by a tapered nozzle that allows inspiratory flow through and around the nozzle, as shown in the exemplary connector 200 of
The connector 200 includes a flow constriction 250 being a nozzle positioned in the inspiratory flow path 280. This nozzle can be attached at various locations to the wall 210 of the connector 200, such as the inner wall 294 of the inlet channel 222 (see
Connector with Filter
In another inventive aspect, there is provided a connector 200 for coupling with an invasive respiratory device 120. The connector 200 includes a main body 210 having a gases port 220 for receiving a flow of gas from a flow source 110 at a selected flow rate, an outlet port 230 for outflow of gases from the main body 210, and a device port 240 couplable with the invasive respiratory device 120. The gases port 220 includes an inlet 216 and an outlet 260. The connector 200 is configured to receive the flow of gas from the flow source 110 via the inlet 216 of the gases port 220, and to deliver a jet flow of gas through the outlet 260 of the gases port 220. The connector 200 further includes a filter 190 couplable with the outlet port 230 for filtering the gases from the main body 210.
In the embodiments of
In the embodiment shown in
Connector with Variable Resistance to Expiratory Flow
According to another inventive aspect, one or more connectors 200 of the present disclosure may be provided with a variable aperture for adjusting resistance to flow of gases exiting the connector through the outlet port 230. The features providing the adjustable aperture may be formed in the main connector body 210 or in a connector body extension (not shown) which couples with the outlet port 230 e.g. by friction fit or threaded coupling. In use, the variable aperture may be used to control resistance to flow of gases exiting through the outlet port 230 (or extended outlet port) which in turn gives rise to different patient pressures achieved within the patient 300 during provision of respiratory support.
Adjusting resistance to flow of gases exiting the outlet port 230 may be useful in some embodiments. For example, increasing resistance to flow through the outlet port 230 by reducing the size of the variable aperture may increase patient pressure which in turn, may increase CO2 clearance. Alternatively/additionally, increasing resistance to flow by decreasing the size of the variable aperture may be desirable to increase Positive End Expiratory Pressure (PEEP).
In one example according to
Although
In another example according to
In
System with Connectors
According to another inventive aspect, there is provided a system 100 for providing respiratory support to a subject 300. The system 100 includes a flow source 110 for providing a gas at a selected flow rate, an invasive respiratory device 120 couplable with an airway of the subject 300, and the connector 200 according to any one of the inventive aspects, or any combinations of the inventive aspects or embodiments as described herein. The system 100 may include any one of the inventive aspects, or any combinations of the inventive aspects with features of embodiments described in connection with the system 100 of
In some embodiments, the system 100 as described herein may also include an optional pressure relief valve, or a sputum catcher. This may be beneficial when the connector 200 is used with a tracheostomy tube for the invasive respiratory device 120.
In some embodiments, the system 100 as described herein may also include a tracheostomy guard, such as described in US20170049982 which is incorporated herein by reference.
Kit with Connector
According to another inventive aspect, there is provided a kit 500 for a system 100 for providing respiratory support to a subject 300. The kit 500 includes the connector 200 according to any one of the inventive aspects, or any combinations of the inventive aspects with features of the embodiments as described herein. The kit 500 also includes at least one of a filter 190 couplable with the outlet port 230 of the connector 200, an invasive respiratory device 120 couplable with the connector 200, and an adapter 126 couplable to the device port 140 of the connector 200 for coupling an invasive respiratory device 120 with the connector 200.
In some embodiments (not shown), the kit 500 may further include an interface conduit 180 connectable between the inlet 216 of the gases port 220 of the connector 200 and a flow source 110 for providing fluid communication (for example, see interface conduit 180 and flow source 110 described with reference to
In some embodiments (not shown), the kit 500 may further including a humidifier 140 for conditioning gas flow provided by a flow source 110 to a selected temperature and/or humidity suitable for delivery to a patient 300 (see also
Kit with Connector and Insert
According to another inventive aspect, there is provided another kit 600 for a system 200 for providing respiratory support to a subject. The kit 600 includes the connector 200 according to any one of the inventive aspects, or any combinations of the inventive aspects with features of embodiments as described herein. The kit 600 also includes the insert 400 according to the inventive aspect or any combinations of the inventive aspect with features of embodiments as described herein.
In some embodiments (not shown), the kit 600 may include one or more inserts 400. Preferably, the kit 600 includes at least two inserts 400 which have different lengths and/or locating features in order to alter the desired distance between the outlet 260 and a distal end portion 122 of an invasive respiratory device 120 when coupled to the connector 200. The inserts 400 may be selected for the kit 600 based on desired outcomes for providing respiratory support to the subject 300.
In some embodiments (not shown), the kit 600 may further include an interface conduit 180 connectable between the inlet 216 of the gases port 220 of the connector 200 and a flow source 110 for providing fluid communication (for example, see interface conduit 180 and flow source 110 described with reference to
In some embodiments (not shown), the kit 600 may further including a humidifier 140 for conditioning gas flow provided by a flow source 110 to a selected temperature and/or humidity suitable for delivery to a patient 300 (see also
Examples illustrating applications of embodiments of the invention will now be described. The examples are supplied to provide context and explain features and advantages of the invention and are not limiting on the scope of the invention as defined in the claims.
The systems tested in respect of the charts shown in
An example of the advantageous effect of lower expiration resistance in relation to the connector 200 of embodiments of the invention can be observed in
In effect, the use of the inventive connector 200 having low expiration resistance may reduce the pressure swing or amplitude, lowering the pressure swing of the patient's breathing in use. The main benefit of reducing this pressure swing is that the inspiration pressure may be higher for a given expiration pressure, and this may make it easier for the patient to inspire and breathe using the inventive system 100 with inventive connector 200, according to embodiments of the invention.
Embodiments of the invention aim to effectively deliver high flow respiratory support invasively by employing a jet flow of gas into an invasive respiratory device (such as an ETT) when in use. The jet flow may be produced by an inventive connector that in some embodiments includes a flow constriction and being located in the inspiratory flow path. The connector may be configured to jet flow of the gas through an outlet and into the ETT. The inventive connector includes various parameters that may be tuned to achieve certain beneficial characteristics. For example, the inventive system may improve respiratory support to a subject by generating a patient pressure that maintains a patent patient airway for a given range of flow rates, and/or providing a low resistance to flow (RTF) in the system, and/or requiring a lower driving pressure in the system. Parameters of the inventive connector may be tuned to address one or more of these system characteristics for providing high flow respiratory support invasively to a patient.
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 any future application. 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.
The present application claims priority from U.S. Provisional Patent Application No. 63/079,651 filed on 17 Sep. 2020 and from U.S. Provisional Patent Application No. 63/202,739 filed on 22 Jun. 2021, the contents of both of which are to be taken as incorporated herein by this reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/NZ2021/050144 | 8/24/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63202739 | Jun 2021 | US | |
| 63079651 | Sep 2020 | US |
