BREATHING ASSISTANCE APPARATUS WITH A MANIFOLD TO ADD AUXILIARY GASES TO AMBIENT GASES

Abstract

The breathing assistance apparatus of the present invention includes a manifold that is provided with or retrofittable to gases supply and humidifying devices. The manifold allows gases from an oxygen concentrator to be combined with the flow through a gases supply and humidifying device, most usually air. The combined output of oxygen and other breathing gases (air) is then humidified. The breathing assistance apparatus and manifold of the present invention provides a safe method to add oxygen to the input air stream of a gases supply and humidifying device and reduces the amount of accumulation of oxygen within the gases supply device, reducing fire risk should sparking occur within the device.

Description

BACKGROUND

Field

This invention relates to a gases supply and gases humidification apparatus including a manifold that allows for the addition of oxygen to the gases supply.

Related Art

A number of methods are known in the art for assisting a patient's breathing. Continuous Positive Airway Pressure (CPAP) involves the administration of air under pressure to a patient, usually by a nasal mask. It is used in the treatment of snoring and Obstructive Sleep Apnoea (OSA), a condition characterized by repetitive collapse of the upper airway during inspiration. Positive pressure splints the upper airway open, preventing its collapse. Treatment of OSA with nasal CPAP has proven to be both effective and safe, but CPAP is difficult to use and the majority of patients experience significant side effects, particularly in the early stages of treatment.

Upper airway symptoms adversely affect treatment with CPAP. Mucosal drying is uncomfortable and may awaken patients during the night. Rebound nasal congestion commonly occurs during the following day, simulating a viral infection. If untreated, upper airway symptoms adversely affect rates of CPAP use.

Increases in nasal resistance may affect the level of CPAP treatment delivered to the pharynx, and reduce the effectiveness of treatment. An individual pressure is determined for each patient using CPAP and this pressure is set at the patient interface. Changes in nasal resistance affect pressure delivered to the pharynx and if the changes are of sufficient magnitude there may be recurrence of snoring or airway collapse or reduce the level of pressure applied to the lungs.

CPAP is also commonly used for treatment of patients with a variety of respiratory illnesses or diseases, including Chronic Obstructive Pulmonary Disease (COPD).

Oxygen is the most common drug prescribed to hospitalized patients with respiratory or other illnesses. The delivery of oxygen via nasal cannula or facemask is of benefit to a patient complaining of breathlessness. By increasing the fraction of inspired oxygen, oxygen therapy reduces the effort to breathe and can correct resulting hypoxia (a low level of oxygen in the tissues).

The duration of the therapy depends on the underlying illness. For example, postoperative patients may only receive oxygen while recovering from surgery while patients with COPD require oxygen 16 to 18 hours per day.

Currently greater than 16 million adults are afflicted with COPD, an umbrella term that describes a group of lung diseases characterized by irreversible airflow limitation that is associated mainly with emphysema and chronic bronchitis, most commonly caused by smoking over several decades. When airway limitation is moderately advanced, it manifests as perpetual breathlessness without physical exertion. Situations such as a tracheobronchial infection, heart failure and also environmental exposure can incite an exacerbation of COPD that requires hospitalization until the acute breathlessness is under control. During an acute exacerbation of COPD, the patient usually experiences an increase in difficulty of breathing (dyspnea), hypoxia, and increase in sputum volume and purulence and increased coughing.

Oxygen therapy provides enormous benefit to patients with an acute exacerbation of COPD who are hypoxic, by decreasing the risk of vital organ failure and reducing dyspnea. The major complication associated with oxygen therapy is hypercarpnia (an elevation in blood carbon dioxide levels) and subsequent respiratory failure. Therefore, the dose of oxygen administered is important.

To accurately control an oxygen dose given to a patient, the oxygen-enriched gas must exceed the patient's peak inspiratory flow to prevent the entrainment of room air and dilution of the oxygen. To achieve this, flows of greater than 20 L/min are common. Such flows of dry gases cause dehydration and inflammation of the nasal passages and airways if delivered by nasal cannula. To avoid this occurrence, a heated humidifier may be used.

The majority of systems that are used for oxygen therapy or merely delivery of gases to a patient consists of a gases supply, a humidifier and conduit. Interfaces include facemasks, oral mouthpieces, tracheostomy inlets and nasal cannula, the latter then having the advantage of being more comfortable and acceptable to the patient than a facemask.

It is usual for the gases supply to provide a constant, prescribed level of gases flow to the humidifier. The humidifier and conduit can then heat and humidify the gases to a set temperature and humidity before delivery to the patient. Many patients using blowers or continuous positive pressure devices to treat COPD are on long term oxygen therapy. Such patients often need in excess of 15 hours per day of oxygen therapy and as such the only practical method to expose these patients to several hours humidification therapy per day as well as oxygen therapy is to combine the oxygen therapy and humidification therapy. As the oxygen therapy is known to dry the airways there are likely to be benefits from combining the treatments.

Currently CPAP systems are commonly integrated with oxygen flow systems to provide increased fraction of oxygen for the treatment of respiratory disorders. These systems commonly combine the oxygen source on the high pressure (flow outlet) side of the blower. This results in three main disadvantages. Firstly, by integrating the oxygen on the high pressure side, a connection port with a sealing cap is required to seal off the oxygen inlet port and avoid high pressure gases escaping when the oxygen flow source is not connected. Secondly, in the event that the oxygen source is turned on before the blower is turned on the breathing circuit, humidification chamber and blower become flooded with 100% oxygen. This is likely to create a fire safety risk if sparking should occur within the blower or heated breathing tube when turned on. Thirdly, if the oxygen gases source is added at the outlet of the humidification chamber, the oxygen gas, when mixed with other gases delivered to the patient, lowers the overall humidity of the gases delivered.

SUMMARY

It is an object of the present invention to provide a breathing assistance apparatus that goes some way to overcoming the abovementioned disadvantages or that at least provides the public or industry with a useful choice.

Accordingly in a first aspect the present invention consists in a breathing assistance apparatus adapted to deliver humidified gases to a patient comprising:

• • a gases supply having an inlet in which gases are drawn through, humidification means including a humidification chamber having an outlet, said gases flowing from said inlet through said humidification chamber and out said outlet, and manifold on or about said gases supply inlet that enables oxygen or other gases to be added to said gases.

Preferably said manifold includes an oxygen inlet port capable of being connected to an oxygen supply.

Preferably said manifold is substantially rectangular.

Preferably said manifold includes at least one aperture to allow the drawing of other gases into said manifold.

Preferably said gases supply includes an internal sensor that is capable of sensing the fraction of oxygen flowing through said breathing assistance apparatus.

Preferably said gases supply includes a controller connected to said internal sensor.

Preferably said gases supply includes a display controlled by said controller and said controller causes said fraction of oxygen to be displayed and updated on said display.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.

In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

One preferred form of the present invention will now be described with reference to the accompanying drawings.

FIGS. 1A-1B are illustrations of the breathing assistance apparatus that may utilize the manifold of the present invention.

FIG. 2 is a rear view of a blower and humidifier apparatus with a manifold of the present invention installed.

FIG. 3 is a rear view of the manifold of the present invention.

FIG. 4 is a first perspective view of the manifold of FIG. 3.

FIG. 5 is a second perspective view of the manifold of FIG. 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The breathing assistance apparatus of the present invention includes a manifold that is preferably provided with or retrofittable to gases supply and humidifying devices. The manifold allows gases from an oxygen concentrator to be combined with the flow through a gases supply and humidifying device, most usually air. The combined output of oxygen and other breathing gases (air) is then humidified.

The breathing assistance apparatus and manifold of the present invention provides a safe method to add oxygen to the input air stream of a gases supply and humidifying device and reduces the amount of accumulation of oxygen within the gases supply device, reducing fire risk should sparking occur within the device.

The present invention provides a breathing assistance apparatus where the flow of gases passes in sequence through a gases supply means or flow driver (such as, a blower, fan or compressor), humidification chamber, heated delivery circuit, then to a patient interface, such as that shown in FIGS. 1A-1B.

Gases are passed to the patient 1 by way of a patient interface 2. The patient interface used with the apparatus of the present invention may be a full-face mask, nasal mask, nasal cannula, oral mouthpiece or tracheostomy connection, but the description below and figures disclose the use of a nasal cannula.

With reference to FIGS. 1A-1B the humidification apparatus of the present invention is shown in which a patient 1 is receiving humidified and pressurized gases through a patient interface 2 (here, a nasal cannula). The cannula 2 is connected to a gases transportation pathway or inspiratory conduit 3 that in turn is connected to an integrated gases supply and humidifying device 4 (including a humidification chamber 5). In the preferred embodiment of the blower-humidifying device 4, the gases supply or blower is combined in one housing with the humidifier and humidification chamber.

In the preferred embodiment, the humidification chamber 5 extends out from the housing 10 and is capable in use of being removed and replaced (by a slide on movement) by the patient or other user. Also, the inlet port (not shown) to the humidification chamber 5 is internal within the housing 10. It must be appreciated that the embodiment described above in relation to the housing and FIGS. 1A-1B merely illustrates one form of the housing of the integrated gases supply and humidifying device. In other forms the gases supply or blower and humidifier may be in separate housings.

The inspiratory conduit 3 is connected to an outlet 8 of the humidification chamber 5 that contains a volume of water 6. Inspiratory conduit 3 contains heating means or heater wires 7 that heat the walls of the conduit to reduce condensation of humidified gases within the conduit and the patient interface 2 (nasal cannula). The humidification chamber 5 is preferably formed from a plastics material and may have a highly heat conductive base (for example an aluminum base) that is in direct contact with a heater plate (not shown but located at the base of the chamber 5, within the blower housing). The gases supply and humidifying device 4 is provided with control means or an electronic controller (illustrated as controller 20) that may comprise a microprocessor based controller executing computer software commands stored in associated memory. The controller 20 receives input from sources such as user input means or dial (not shown) through which a user of the device 4 may, for example, set a predetermined required value (preset value) of humidity or temperature of the gases supplied to patient 1.

In response to the user set humidity or temperature value input via dial (or buttons) and other possible inputs such as internal sensors that sense gases flow or temperature, or by parameters calculated in the controller 20, the controller 20 determines when (or to what level) to energize heater plate to heat the water 6 within humidification chamber 5. As the volume of water 6 within humidification chamber 5 is heated, water vapor begins to fill the volume of the chamber above the water's surface and is passed out of the humidification chamber outlet (illustrated as outlet 8) with the flow of gases (for example air) provided from a blower part of the device that has entered the device 4 through an inlet 9 on the back of the gases supply and humidifying device 4.

The gases supply within the device 4 is preferably a variable speed pump 22 or fan 23 that draws air or other gases through the blower inlet (illustrated as inlet 9). The speed of variable speed pump 22 or fan 23 is preferably controlled by the control means or electronic controller (illustrated as controller 20) described above in response to inputs entered into the device 4 by the user.

As discussed above it would be advantageous to provide oxygen therapy with humidification therapy to patients that suffer from COPD and other respiratory disorders. The breathing assistance apparatus of the present invention provides this by having a manifold that is attachable to existing gases supply and humidifying devices, such as, the SleepStyle™ 600 series CPAP devices of Fisher & Paykel Healthcare Limited. It must be noted that any CPAP, auto PAP, bi-level or other flow generating device that provides high gases flow and potentially humidification of gases may utilize a manifold as described below. The manifold allows the output from an oxygen concentrator to be combined with the flow from a gases supply and humidifying device and the combined output of oxygen and other breathing gases can then be humidified.

FIG. 2 shows a gases supply and humidifying device 4 with a manifold 11 installed. The manifold 11 is shown in further detail in FIGS. 3 to 5. The manifold 11 is preferably a substantially rectangular insert that is capable of being inserted into the inlet port 9 on the device 4. The manifold 11 has a recessed edge 12 that fits into a complementary lip on the inlet port 9 and has an oxygen inlet port 13 to which tubing 14 or the like can be attached that feeds to an oxygen supply tank or the like. The oxygen inlet port 13 preferably extends from the side of the manifold 11. The manifold 11 has an extended area 15 that includes at least one aperture (although two apertures 16, 17 are shown in FIGS. 3 to 5). The apertures 16, 17 allow for ambient air to be drawn into the device 4 by the action of the pump 22 or fan 23. The ambient air plus oxygen gases are mixed within the device 4 and exit the chamber outlet (illustrated as outlet 8) as humidified air plus oxygen that is then passed to the patient via the conduit 3.

A filter 21, for example, a substantially rectangular piece of meshed filter material or the like, may be placed inside the apertures 16, 17, such that it fits within the inner part of the extended area 15 and filters all gases entering the blower inlet.

Advantages

This breathing assistance apparatus and manifold of the present invention provides a safe method to add oxygen to the input air stream of a gases supply and humidifying device. The full oxygen output from the tubing feeding oxygen to the manifold is drawn into the device when the device is in use, but if the device is switched off oxygen that is fed into the manifold disperses through the apertures 16, 17 and therefore remains outside the device 4. Therefore, oxygen does not accumulate within the device (for example, a gases supply such as a blower) and create a fire risk. Consequently, the manifold lowers the fire hazard risk should a spark occur inside the blower or breathing conduit.

By adding oxygen to the inlet of the flow generation device this oxygen can be fully humidified along with the other gases delivered to the patient. Prior art systems usually add oxygen after humidification of gases thus reducing the overall humidification of the gases that reach the patient.

Furthermore, adding oxygen on the inlet side of the flow source makes it possible to sense inside the device 4 the fraction of oxygen in the combined gas flow and display this fraction on a display on the flow source. Therefore, in a further embodiment the gases supply (blower or integrated blower and humidifying device 4) includes an internal sensor 19 that is capable of sensing the fraction of oxygen through the device 4. The internal sensor 19 is preferably connected to the controller 20 within the device (as described above) and the controller 20 causes the fraction of oxygen measurement sensed by the internal sensor 19 to be displayed on the display 18 (see FIG. 2) that is preferably disposed on the top of the device 4. As the fraction of oxygen changes and this is sensed by the internal sensor 19 preferably this change is updated on the display in real time.

The breathing assistance apparatus with the manifold of the present invention does not require one way valves or sealing caps when an oxygen circuit is not connected to the apparatus and is safe and simple for a patient to operate.

Claims

1-32. (canceled)

33. A system for sensing and displaying oxygen fraction in a combined gas flow of a breathing assistance apparatus, the system comprising: a sequential flow path comprising; an initial safety manifold having a bifurcated intake structure configured to intake ambient gas through one opening and intake pure oxygen through another opening, thereby creating downstream a flow of combined gases when a flow driver is activated and allowing pure oxygen to disperse when the flow driver is not activated;a subsequent, widened humidification chamber configured to heat fluid and thereby simultaneously humidify the flow of combined ambient gas and pure oxygen;the flow driver positioned downstream from the safety manifold and configured to cause flow of the combined gases through the sequential flow path;a sensor in fluid communication with the combined gases and configured to determine the fraction of oxygen in the flow of combined gases; anda combined gases outlet configured to allow the flow of combined gases to exit; anda housing for the breathing assistance apparatus and the sequential flow path, the housing configured to: support the safety manifold on an external surface of the housing;integrate the flow driver and humidifier;combine a humidifier and the humidification chamber such that the humidification chamber can be removed from the housing and replaced;provide support for the combined gases outlet such that combined gases flow from the housing and sequential flow path and out through the outlet toward a patient; andsupport a display configured to receive output from the sensor and, on the housing, display fraction of oxygen information for combined gases flowing through the system.

34. The system of claim 33, wherein the sensor is included in the flow driver.

35. The system of claim 33, wherein the housing further comprises an inlet port and the manifold comprises a substantially rectangular insert that is capable of being inserted into the inlet port.

36. The system of claim 34, wherein the manifold has a recessed edge that fits into a complementary lip on the inlet port.

37. The system of claim 33, wherein the pure oxygen opening is configured to accept an attachment from tubing that feeds from an oxygen supply.

38. The system of claim 33, wherein the pure oxygen opening comprises a port configured to extend from the manifold in a direction parallel to a surface of an adjacent face of the apparatus housing.

39. A control system for a breathing assistance apparatus, the system comprising: an input configured to accept instruction from a user for a required humidity or temperature for a combined flow of gases to be provided by a breathing assistance apparatus;at least one sensor configured to empirically determine humidity or temperature of the combined flow of gases inside the breathing assistance apparatus;a controller configured to receive a signal from the input reflecting the instruction, to receive feedback signals from the at least one sensor, and to adjust energy to components of the apparatus to change the humidity or temperature of the combined flow of gases;a display configured to interact with the input, the at least one sensor, and the controller;a housing that supports the display and input, encloses the controller and the at least one sensor, and integrates a gases supply and a humidifier such that the gases supply causes a flow of gases through the apparatus and through the humidifier, the gases entering the housing at a housing inlet; andon or about the housing inlet, a manifold having an ambient air aperture configured to entrain ambient air into the aperture and into the inlet and an auxiliary gases opening configured to entrain auxiliary gases into the opening and into the inlet such that, when the gases supply is operating, ambient air and auxiliary gases form, at the inlet, the combined flow of gases.

40. The system of claim 39, wherein the manifold is removable from the housing.

41. The system of claim 39, wherein the manifold includes a filter configured to remove particulate matter from ambient air as that air is entrained into the inlet.

42. The system of claim 39, wherein the gases supply and the humidifier each form a component of the apparatus and each is configured to accept energy as controlled by the controller.

43. The system of claim 42, wherein the humidifier comprises a heater plate integrated into the housing and a humidification chamber configured for rapid removal from the housing.

44. The system of claim 42, wherein the at least one sensor comprises a sensor configured to sense the fraction of oxygen within the combined flow of gases within the housing and the display is configured to show the sensed fraction of oxygen.

45. The system of claim 39, wherein the controller is further configured to control flow of the combined flow of gases by adjusting energy to the gases supply.

46. The system of claim 39, wherein the controller is further configured to control temperature and humidity of the combined flow of gases by adjusting energy to the heater plate.

47. The system of claim 39, wherein the housing further comprises an inlet port, the manifold comprises an insert that is capable of being inserted into the inlet port, and the manifold has a recessed edge that fits into a complementary lip on the inlet port.

48. A device for combining and controlling a flow of gases, the device comprising: a housing having an input and display configured to provide access to information and related control to a user;at least one sensor configured to empirically determine humidity or temperature of a combined flow of gases inside the housing;a controller configured to receive signals from the input and the at least one sensor, control humidity or temperature of the combined flow of gases, and send signals to the display related to humidity or temperature of the combined flow of gases;the housing integrating a gases supply and a humidifier such that the gases supply causes a flow of gases through the apparatus and through the humidifier, the gases entering the housing at a housing inlet port;on or about the housing inlet, a manifold having an ambient air aperture configured to accept ambient air into the aperture and into the inlet and an auxiliary gases opening configured to accept auxiliary gases into the opening and into the inlet such that, when the gases supply is operating, ambient air and auxiliary gases form, at the inlet, the combined flow of gases; andthe housing inlet port and manifold further comprises a lip and recessed edge that fit together in a complementary manner.

49. The system of claim 48, wherein the controller is configured to control humidity or temperature of the combined flow of gases by adjusting energy to the gases supply or humidifier.

50. The system of claim 48, wherein the manifold is removable from the housing.

51. The system of claim 48, wherein the manifold includes a filter configured to remove particulate matter from ambient air as that air enters the inlet.

52. The system of claim 48, wherein the humidifier comprises a heater plate integrated into the housing and a humidification chamber configured for rapid removal from the housing.

53. The system of claim 52, wherein the controller is further configured to control temperature and humidity of the combined flow of gases by adjusting energy to the heater plate.

54. The system of claim 48, further comprising an oxygen sensor configured to sense the fraction of oxygen within the combined flow of gases within the housing and the display is configured to show the sensed fraction of oxygen.

55. The system of claim 48, wherein the controller is further configured to control flow of the combined flow of gases by adjusting energy to the gases supply.