GB2595242A

GB2595242A - Method and apparatus

Info

Publication number: GB2595242A
Application number: GB2007346.6A
Authority: GB
Inventors: Mebrate Yoseph; Polkey Michael
Original assignee: Imperial College Innovations Ltd
Current assignee: Ip2ipo Innovations Ltd
Priority date: 2020-05-18
Filing date: 2020-05-18
Publication date: 2021-11-24
Also published as: GB202007346D0; WO2021234375A1

Abstract

Means for increasing the oxygen efficiency of a ventilator, comprising an oxygen inlet 410 for receiving oxygen from an external oxygen supply 412, a gas inlet 440 for intaking atmospheric gas, and a fluid portal 420 for receiving discarded gas from the ventilator and inputting gas into the ventilator. Oxygen is collected in a storage reservoir 450 and preferentially supplied to the ventilator over gas entering through the gas inlet. The preferential oxygen supply may be provided by a biased, expanding oxygen reservoir or property of the tubes connecting the reservoir 452 and atmospheric intake 442 that may be flexible or compressible tubes varying in flow resistance or length. The means may comprise an attachment for coupling to an intake & exhaust port of an existing ventilator. An oxygen sensor may monitor the oxygen output of the ventilator. Methods for enhancing the oxygen efficiency of a ventilator and modifying ventilators.

Description

Method and Apparatus

Technical Field

The present disclosure relates to the technical field of ventilators. In particular, the present disclosure relates to the technical field of providing increased oxygen usage efficiency for ventilators.

Background

Ventilators are used to facilitate breathing for patients with breathing difficulties. As an example, ventilators have been used for patients suffering from breathing difficulties brought about by Covid-19. Ventilators generally fall into one of two types: ventilators which have a designated oxygen inlet, and those which do not.

Embodiments of the present disclosure aim to provide improved oxygen usage efficiency for both types of ventilators.

Summary

Aspects of the disclosure are set out in the independent claims and optional features are set out in the dependent claims. Aspects of the disclosure may be provided in conjunction with each other, and features of one aspect may be applied to other aspects.

In an aspect, there is provided a method of increasing the oxygen efficiency of a ventilator.

The ventilator comprises a fluid portal connected to both (i) an oxygen storage reservoir and (ii) a gas inlet for allowing gas from the atmosphere to flow to the fluid portal. The method comprises: collecting and storing oxygen in the oxygen storage reservoir connected to the fluid portal of the ventilator, wherein said oxygen is supplied to the ventilator by an oxygen supply from an external oxygen store; and providing the collected oxygen from the oxygen storage reservoir to the ventilator in preference to providing gas from the atmosphere received through the gas inlet.

The oxygen storage reservoir and the gas inlet may be connected to a ventilator connection configured for connection to the fluid portal of the ventilator. The oxygen storage reservoir may be connected to the ventilator connection by a first portion of tubing. The gas inlet may be connected to the ventilator connection by a second portion of tubing. A property of the first portion of tubing may be different to a corresponding property of the second portion of tubing. The second portion of tubing may be longer than the first portion of tubing.

The connection between the fluid portal and the oxygen storage reservoir may have a lower flow resistance to the flow of oxygen than the connection between the gas inlet and the fluid portal. For example, a lower flow resistance to the flow oxygen may provide a preferential flow of oxygen to an alternative path having a higher flow resistance. For example, a preferential flow may be provided between the fluid portal and the oxygen storage reservoir than as compared to the flow of oxygen between the gas inlet and the fluid portal. Providing increased flow resistance may comprise providing higher back pressure to this flow.

The ventilator may comprise an oxygen inlet configured to receive oxygen from the external oxygen store. Some of the oxygen supplied to the ventilator through the oxygen inlet may be vented through fluid portal and collected and stored in the oxygen storage reservoir. The ventilator may receive both stored oxygen from the oxygen storage reservoir and supplied oxygen from the external oxygen store.

The external oxygen store may also be connected to the fluid portal of the ventilator.

In an aspect, there is provided an adaptor for a ventilator. The ventilator comprises: (i) an oxygen inlet for receiving oxygen from an external oxygen supply, and (ii) a fluid portal for both discarding oxygen from the ventilator to the environment and for inputting gas from the environment for mixture with oxygen in the ventilator. The adaptor comprises: an oxygen storage reservoir; and a ventilator connection connected to the oxygen storage reservoir.

The ventilator connection is configured to connect the adaptor to the fluid portal of a said ventilator to enable: (i) oxygen discarded from the ventilator through the fluid portal to be collected and stored in the oxygen storage reservoir, and (ii) oxygen collected in the oxygen storage reservoir to be provided to the ventilator.

In an aspect, there is provided an adaptor for a ventilator. The ventilator comprises: (i) a fluid portal for receiving gas from the environment. The adaptor comprises: an oxygen connection configured to connect the adaptor to an external oxygen supply; an oxygen storage reservoir connected to the oxygen connection to enable oxygen from the external oxygen supply to be collected and stored in the oxygen storage reservoir; and a ventilator connection connected to the oxygen connection and the oxygen storage reservoir. The ventilator connection is configured to connect the adaptor to the fluid portal of a said ventilator to enable oxygen collected in the oxygen storage reservoir to be provided to the ventilator.

The adaptor may further comprise a gas inlet for receiving gas from the environment. The adaptor may be arranged to enable oxygen from the oxygen storage reservoir to be input to the ventilator in preference to gas from the environment. The connection between the oxygen storage reservoir and the ventilator connection may have a lower flow resistance than the connection between the gas inlet and the ventilator connection thereby to provide a preferential flow of oxygen between the oxygen storage reservoir and the ventilator connection. The connection between the oxygen storage reservoir and the ventilator connection may comprise a first portion of tubing and the connection between the gas from the environment and the ventilator connection comprises a second portion of tubing. A property of the first portion of tubing is different to a corresponding property of the second portion of tubing thereby to provide the connection between the oxygen storage reservoir and the ventilator connection with a lower flow resistance than the connection between the gas from the environment and the ventilator connection. The second portion of tubing may be longer than the first portion of tubing. At least one of the first and second portions of tubing may be flexible and/or compressible.

The oxygen storage reservoir may comprise an expandable portion. The adaptor may be made of a biocompabble material.

In an aspect, there is provided a ventilator comprising: a fluid portal; an oxygen storage reservoir connected to the fluid portal; and a gas inlet connected to the fluid portal, wherein the gas inlet is configured to receive gas from the atmosphere. The ventilator is configured to: collect and store oxygen supplied from an external oxygen store in the oxygen storage reservoir; and provide oxygen collected in the oxygen storage reservoir to the ventilator in preference to providing gas from the atmosphere received through the gas inlet.

The ventilator may further comprise an oxygen sensor configured to obtain an indication of an oxygen concentration of respirable gas output from the ventilator. The ventilator may be configured to output a control signal in the event that an obtained indication of oxygen concentration is not within a selected concentration range.

In an aspect, there is provided a method of modifying a ventilator. The ventilator comprises: an oxygen inlet for receiving oxygen from an external oxygen supply; and a fluid portal for both discarding oxygen from the ventilator to the environment and for inputting gas from the environment for mixture with oxygen in the ventilator. The method comprises modifying the ventilator so that: oxygen discarded through the fluid portal is collected and stored in an oxygen storage reservoir connected to the fluid portal and oxygen collected in the oxygen storage reservoir is provided to the ventilator.

In an aspect, there is provided a method of modifying a ventilator. The ventilator comprises a fluid portal for receiving gas from the environment. The method comprises modifying the ventilator so that: the ventilator is connected to both an external oxygen supply and an oxygen storage reservoir, wherein the oxygen storage reservoir is operable to collect and store oxygen supplied from the external oxygen supply; and oxygen collected in the oxygen storage reservoir is provided to the ventilator.

Figures Some examples of the present disclosure will now be described, by way of example only, with reference to the figures, in which: Figs. la and lb are schematic diagrams of a ventilator.

Figs. 2a and 2b are schematic diagrams of an adaptor for a ventilator.

Figs. 2c and 2d are schematic diagrams of the ventilator of Figs. 2a and 2b in combination with the ventilator of Figs. la and lb. Figs. 3a and 3b are schematic diagrams of a ventilator.

Figs. 4a and 4b are schematic diagrams of an adaptor for a ventilator.

Figs. 4c and 4d are schematic diagrams of the ventilator of Figs. 4a and 4b in combination with the ventilator of Figs. 3a and 3b.

In the drawings like reference numerals are used to indicate like elements.

Specific Description

Embodiments of the present disclosure are directed to methods of using and/or modifying a ventilator to provide increased oxygen usage efficiency for the ventilator. Embodiments of the present disclosure are also directed to such ventilators, as well as adaptors for modifying ventilators to provide increased oxygen usage efficiency. Some embodiments are directed to reducing the amount of oxygen that would be discarded to the environment by a ventilator by collecting and storing such oxygen instead of discarding it. This stored oxygen can then be provided back to the ventilator for use. In some embodiments, ventilators are connected to an external oxygen supply, and excess oxygen provided by the supply is collected and stored to reduce wastage of oxygen. This stored oxygen can then be provided to the ventilator for use. Embodiments may therefore increase oxygen usage efficiency of ventilators by reducing the amount of discarded (e.g. unused) oxygen. Embodiments may also provide increased oxygen to the ventilator by providing the ventilator with a supply of oxygen.

One specific example of a ventilator and adaptor for modifying the ventilator will now be described with reference to Figs. 1 and 2. It will be appreciated in the context of the present disclosure that this is one specific example, and other embodiments fall within the scope of the appended claims.

Figs. la and lb show an example of a ventilator 100. The ventilator 100 is of the type which includes a designated oxygen inlet, i.e. the ventilator 100 includes an oxygen inlet 110. The ventilator 100 is a medical ventilator. The ventilator 100 also includes a fluid portal 120 and a gas outlet 130. An oxygen fluid line 112 is connected to the oxygen inlet 110. A valve 132 is provided in the gas outlet 130. Each of the oxygen inlet 110, the fluid portal 120 and the gas outlet 130 are fluidly coupled inside the ventilator (e.g. by a series of pumps, valves, sensors and/or other components inside the ventilator).

The ventilator 100 illustrated in Figure la is configured to receive oxygen supplied through the oxygen inlet 110 from an external oxygen supply such as might be provided from an oxygen cylinder or an oxygen supply system in a clinical setting. The ventilator 100 may include a pump or motor to provide driven a flow of gas. The ventilator 100 is configured to take in gas from both the oxygen inlet 110 and the fluid portal 120 and to output this gas through the gas outlet 130. For example, a pump may provide driven flow for this intaking and outputting of gas. The ventilator 100 may include one or more filters for filtering gas in the ventilator 100 (such as that drawn in through the oxygen inlet 110 and/or the fluid portal 120).

The gas outlet 130 includes a valve 132 to enable selective flow through the outlet.

However, it is to be appreciated that a valve 132 may not be necessary, as selective flow through the outlet could be controlled using a pump of the ventilator 100. The outlet is configured to output respirable gas. For example, such gas may ultimately be delivered to a patient to facilitate breathing.

The fluid portal 120 comprises a vent to the environment so that excess gas in the ventilator 100 may flow out through the vent. In addition, air may be drawn into the ventilator 100 through the vent, this can enable air from the environment surrounding the ventilator to be mixed with oxygen supplied from the external oxygen supply (e.g. through the oxygen inlet 110) inside the ventilator 100. For example, the vent may comprise a hole or other access means to allow air to flow into and out from the ventilator 100. A filter may be provided to filter gases travelling into the ventilator 100 through the vent. The fluid portal 120 may be thus configured to enable gas from the environment to flow into ventilator 100 to mix with oxygen to provide a supply of oxygen enriched respirable air for supply to a patient.

For example, the ventilator 100 may be arranged so that oxygen supplied from the external oxygen supply through the inlet 110 passes into a region of the ventilator 100 in which this oxygen mixes with gas drawn in through the fluid portal 120. The ventilator is arranged to enable this mixture of gas to be drawn into a blower (e.g. a pump) which drives flow of the mixed gas towards the outlet 130. The ventilator 100 may be arranged so that this driven mixture of gas passes through one or more sensors, and/or a bypass chamber before flowing out of the ventilator 100 (e.g. in a tube connected to the outlet 130).

In operation, oxygen is supplied to the ventilator 100 from the external oxygen supply through the oxygen inlet 110. This oxygen is continually supplied to the ventilator 100. "Mien the valve 132 is shut (as shown in Fig. la), oxygen enters the ventilator 100 through the oxygen inlet 110, and passes out through the fluid portal 120 to the environment. When the valve 132 is open (as shown in Fig. lb), oxygen enters the ventilator 100 through the oxygen inlet 110. Gas from the environment also enters the ventilator 100 through the fluid portal 120. This gas mixes with the oxygen in the ventilator 100 and flows out through the output for supply to a patient. Embodiments of the present disclosure are directed to systems and methods for reducing the amount of oxygen that is wasted in this process. In other words, embodiments are directed to reducing this oxygen wastage and improving the oxygen usage efficiency of a simple passive air supplied ventilator 100 such as that illustrated in Fig la.

One method of improving the efficiency of oxygen usage is to collect gas vented from the fluid portal and to store that oxygen rich gas in an oxygen storage reservoir. The stored gas can then be provided to the fluid portal so that it is drawn back into the ventilator through the fluid portal to be mixed with the supplied oxygen in preference to air from the environment surrounding the ventilator. This may be done in a variety of different ways. One example will now be described with reference to Figure 2a.

Fig. 2a shows an adaptor 200 which may be used to provide improvements in oxygen usage efficiency for the ventilator 100. Such an adaptor 200 may be used to modify existing ventilators. The adaptor 200 may enable the ventilator 100 to be modified to increase the amount of oxygen used by the ventilator per unit time, such as to increase the concentration of oxygen used by a ventilator. For example, this may comprise providing increased Fi02 as a greater amount and/or concentration of oxygen can be output from the ventilator.

The adaptor 200 includes a ventilator connection 220 for connecting the adaptor to the fluid portal of a ventilator. The adaptor 200 also comprises an oxygen storage reservoir 250. The adaptor 200 also includes a gas inlet 240 which includes a gas permeable portion 244 such as a filter for the intake of air from the environment surrounding the adaptor. The oxygen storage reservoir 250 is connected to the ventilator connection 220 via a first portion of tubing 252. The gas inlet 240 is connected to the ventilator connection 220 via a second portion of tubing 242. Each of the oxygen storage reservoir 250, gas inlet 240 and ventilator connection 220 are fluidly connected. These connections are provided by pieces of tubing (such as the first and second portions of tubing). The components of the adaptor 200 are biocompatible. The adaptor 200 may be enclosed to prevent inflow or outflow of gas from the adaptor 200 other than via the gas inlet 240 and the ventilator connection 220.

The oxygen storage reservoir 250 is provided by an expandable container, such as an inflatable sack. The oxygen storage reservoir 250 is connected to the ventilator connection 220 by a shorter piece of tubing (e.g. the first portion of tubing 252) than the piece of tubing connecting the gas inlet 240 to the ventilator connection 220 (e.g. the second portion of tubing 242) The adaptor 200 is configured to cooperate with a corresponding ventilator 100, for example by providing a seal (e.g. substantially gas tight connection) between the ventilator connection and the fluid portal so that all air flowing out from and into the fluid portal must flow through the adaptor 200. The adaptor 200 may thus be configured to enable such a ventilator 100 to be modified through use of such an adaptor 200.

For example, the ventilator connection 220 can be configured to fit the fluid portal 120 of the ventilator 100, e.g. so that it is engageable with said fluid portal 120 to enable the adaptor to be connected to the ventilator 100 using the ventilator connection 220 and the fluid portal 120. The ventilator connection 220 is configured to enable the adaptor 200 to be attached to (e.g. mechanically fixed to) the ventilator 100 using the connection of the ventilator connection 220 with the fluid portal 120. For example, the adaptor 200 may be sized and shaped to mate with the fluid portal 120 (e.g. to securely fit inside the portal 120 to retain the adaptor 200 attached to the ventilator 100, such as by providing a snug fit). In this example, the ventilator connection 220 has the same shape as the fluid portal 120 and it is slightly smaller than the fluid portal 120 so that when inserted into the fluid portal 120, there is sufficient friction between the ventilator connection 220 and the fluid portal 120 to attach the adaptor 200 to the ventilator 100. It is to be appreciated in the context of the present disclosure that the exact size and/or shape of the ventilator connection 220 is not to be considered limiting and instead this may be determined based on the size and/or shape of the fluid portal 120.

The oxygen storage reservoir 250 is configured to store oxygen gas. The reservoir 250 is expandable so that it can expand to accommodate oxygen gas. The reservoir 250 may be provided by an expandable container such as a bellows or sack. The container may have a similar size to a human lung (e.g. with a volume which corresponds to that of an adult human lung, e.g. an adult human male or an adult human female). The reservoir 250 may be biased into its unexpanded configuration (for example it may comprise resiliently expandable walls) so that oxygen stored in the reservoir 250 tends to be pushed back out of the reservoir 250.

The oxygen storage reservoir 250 is connected to the fluid portal 120 so that oxygen gas entering the adaptor 200 through the ventilator connection 220 is delivered to the reservoir 250. The tubing connecting the ventilator connection 220 and the reservoir 250 (the first portion of tubing 252) provides a lower flow resistance to the flow of oxygen (e.g. it may provide a lower back pressure) than that connecting the ventilator connection 220 to the gas inlet 240 (the second portion of tubing 242). The tubing may be substantially straight between the ventilator connection 220 and the reservoir 250 (e.g. to reduce friction losses for flow of gas). This may enable a greater proportion of the oxygen entering the adaptor 200 to be delivered to the reservoir 250 (rather than through the gas inlet 240).

The gas inlet 240 comprises an inlet for gas to enter/exit the adaptor 200 from the environment. As shown, this comprises a gas permeable portion 244 such as a filter, but this is not to be considered limiting. The filter is optional and/or may be made and sold separately. When present, it may be used to purify gases flowing in through the gas inlet 240. The gas inlet 240 is connected to the ventilator connection 220 by a longer piece of tubing than the reservoir 250 (as shown this is also a more tortuous piece of tubing). This is one way to increase the flow resistance of this connection to the gas inlet 240, e.g. by providing a greater dead volume between the inlet 240 and the ventilator connection 220.

Providing an air filter at the gas inlet may also increase this flow resistance. The flow path between the ventilator connection 220 and the gas inlet 240 may therefore enable oxygen to flow from the oxygen storage reservoir 250 to the ventilator connection 220 in preference to flowing between the ventilator connection 220 and the gas inlet 240. This arrangement may enable oxygen discarded from the ventilator 100 through the fluid portal 120 to be stored in the reservoir 250 in preference to flowing out through the gas inlet 240. In addition, when flow through the vent is reversed, e.g. when the ventilator draws air back in through the vent to be mixed with supplied oxygen in the ventilator 200 (as supplied through the oxygen inlet 110), this arrangement may enable oxygen stored in the reservoir 250 to be provided to the ventilator 100 through the ventilator connection 220 in preference to gas from the gas inlet 240.

Advantageously, by balancing (a) the flow resistance provided by the tubing between the inlet 240 and the ventilator connection 220 against (b) the flow resistance provided by the tubing between the ventilator connection 220 and the oxygen reservoir 250, this function may be provided without the need for active control and without the need for any modification of the workings of the ventilator. The tubing connecting the gas inlet 240 to the respirator connection 220 may have a length of between 5 cm and 50 cm, such as between 10 cm and 50 cm. For example, the tubing may have a length of greater than 10 cm, such as greater than 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, or 45 cm.

Fig. 2b shows the adaptor 200 of Fig. 2a with the reservoir 250 in an inflated state.

Operation of the adaptor 200 of Figs. 2a and 2b, as assembled on the ventilator 100 of Figs. la and lb will now be described with reference to Figs. 2c and 2d.

In Fig. 2c, the valve 132 is closed. Oxygen is supplied to the ventilator 100 through the oxygen inlet 110 and this oxygen passes through the fluid portal 120. The adaptor 200 is connected to the ventilator 100 with the ventilator connection 220 connected to the fluid portal 120. The oxygen therefore flows out through the fluid portal 120 and into the adaptor 200. Once in the adaptor 200 this oxygen then carries on flowing through the adaptor 200. A majority of this oxygen will flow into the oxygen storage reservoir 250. The oxygen storage reservoir 250 will inflate as it stores more oxygen. A portion of this oxygen will flow out towards the gas outlet 130, but the majority will flow into the oxygen storage reservoir 250.

This continues as the oxygen inlet 110 continues to supply oxygen to the ventilator 100 and the valve 132 is closed.

In Fig. 2d, the valve 132 is opened. Oxygen is supplied to the ventilator 100 through the oxygen inlet 110. Gas is also supplied to the ventilator 100 through the fluid portal 120. A majority of the gas supplied through the fluid portal 120 will be oxygen from the oxygen storage reservoir 250 (as shown in Fig. 2d, the oxygen storage reservoir 250 is inflated with oxygen). This oxygen flows from the storage reservoir 250 along the first portion of tubing 252 and through the fluid portal 120 and into the ventilator 100. A portion of the gas flowing into the ventilator 100 through the fluid portal 120 will include gas from the environment through gas inlet 240. It may also include previously-discarded oxygen located between the ventilator 100 and the gas inlet 240.

It is to be appreciated in the context of the present disclosure that the arrangement shown in Fig. 2 may enable a reduction in the amount of wasted oxygen, and thus provided an increase oxygen usage efficiency for a ventilator 100. This may also provide a greater amount of oxygen output by the ventilator 100. For example, Fi02 (fraction of inspired oxygen) provided by the ventilator 100 may be increased (e.g. the output from the ventilator may have a higher concentration of oxygen in it).

Another specific example of a ventilator and an adaptor for modifying said ventilator will now be described with reference to Figs. 3 and 4. It will be appreciated in the context of the present disclosure that this is one specific example, and that it is not to be considered limiting. Alternatives of this system are described later to illustrate that not all of the features of Figs. 3 and 4 are required and/or that additional features may also be included.

Figs. 3a and 3b show a ventilator 300. The ventilator 300 is of the type which does not include a designated oxygen inlet. The ventilator 300 includes a fluid portal 320. The ventilator 300 also includes a gas outlet 330, which includes a valve 332. The fluid portal 320 is fluidly connected to the gas outlet 330. The gas outlet 330 and valve 332 may correspond to those described above, and so shall not be described again here. The fluid portal 320 is similar to that described above. The fluid portal 320 is arranged to receive gas from the atmosphere. This gas is typically filtered after passing into the ventilator 300 from the portal 320. Unlike in the example described above, the ventilator 300 is not arranged for gas passing in through the fluid portal 320 to mix with oxygen in the ventilator 300, as no oxygen is provided to the ventilator 300. As with the example described above, a pump may be provided to provide driven flow of gas.

In Fig. 3a the valve 332 is closed and so gas does not flow out through the gas outlet 330. The fluid portal 320 may remain open, but as the valve 332 is shut, no substantial flow of gas into the ventilator 300 through the fluid portal 320 occurs. In Fig. 3b the valve 332 is open and so gas flows from the ventilator 300 and out through the outlet. Gas flows into the ventilator 300 through the fluid portal 320 and may be purified by a filter before flowing out through the outlet.

Embodiments of the present disclosure are directed to systems and methods for providing improved oxygen usage and usage efficiency for such a ventilator 300. In other words, embodiments are directed to increasing the amount of oxygen which may be output through the gas outlet 330 of the ventilator 300. This increase in oxygen efficiency by the ventilator 300 may be done while inhibiting oxygen wastage and improving the oxygen usage efficiency of the ventilator 300.

Figs. 4a and 4b show an adaptor 400 which may be used to provide improvements in oxygen usage efficiency for the ventilator 300. Such an adaptor 400 may be used to modify existing ventilators.

The adaptor 400 is similar to that described above, and so details of features corresponding to those described above shall not be repeated again here.

The adaptor 400 includes a ventilator connection 420 and an oxygen storage reservoir 450.

The oxygen storage reservoir 450 is connected to the ventilator connection 420 by a first portion of tubing 452. The apparatus includes a gas inlet 440. The gas inlet 440 is connected to the ventilator connection 420 by a second portion of tubing 442. The gas inlet 440 includes a gas permeable region 444.

The adaptor 400 also includes an oxygen connection 410. The oxygen connection 410 connects the adaptor 400 to an external oxygen source via an oxygen fluid inlet line 412. The oxygen connection 410 comprises a piece of tubing with an attachment for connection to the oxygen fluid inlet line 412. Each of the gas inlet 440, the oxygen connection 410, the oxygen storage reservoir 450 and the ventilator connection 420 are fluidly connected to one another. The oxygen connection 410 is located adjacent the oxygen storage reservoir 450. The oxygen storage reservoir 450 is arranged to be connected to the ventilator connection 420 via a straight piece of tubing. The gas inlet 440 is between the oxygen connection 410 and the ventilator connection 420.

Fig. 4b shows the adaptor 400 with the oxygen storage reservoir 450 inflated.

Operation of the adaptor 400 of Figs. 4a and 4b, as assembled on the ventilator 300 of Figs. 3a and 3b will now be described with reference to Figs. 4c and 4d.

In Fig. 4c the valve 332 is shut. Gas does not flow through the outlet. There is no significant flow of gas either way through the fluid portal 320. Oxygen is continually supplied to the adaptor 400 through the oxygen connection 410. The majority of this oxygen flows from the oxygen connection 410 and into the oxygen storage reservoir 450. A portion of this oxygen will flow through the gas inlet 440, and also another portion may flow into the ventilator 300. However, the majority will flow into the oxygen storage reservoir 450. The oxygen storage reservoir 450 will then inflate with the oxygen it is storing.

In Fig. 4d the valve 332 is open. Gas flows through the outlet. Gas is drawn into the ventilator 300 through the fluid portal 320. This gas drawn into the ventilator 300 includes oxygen supplied through the oxygen connection 410, as well as oxygen provided from the oxygen storage reservoir 450. This will also include some air from the gas inlet 440, but the majority of the gas provided to the ventilator 300, and thus out through the outlet, will be sourced from the oxygen connection 410 and the oxygen storage reservoir 450.

It is to be appreciated in the context of the present disclosure that the arrangement shown in Fig. 4 may enable an increase in the oxygen usage efficiency for a ventilator. This may also provide a greater amount of oxygen output by the ventilator. For example, Fi02 (fraction of inspired oxygen) provided by the ventilator may be increased (e.g. the output from the ventilator may have a higher concentration of oxygen in it).

In examples described above, the ventilator connection is described as providing a connection between the adaptor and the ventilator. It is to be appreciated in the context of the present disclosure that this connection is to enable flow of fluids (e.g. gas such as oxygen gas) between the ventilator and the adaptor. The adaptor may be secured to the ventilator using this connection between the ventilator connection and the fluid portal.

However, it is to be appreciated that this should not be considered limiting. Other attachment means may be provided to secure the two components together. For example, adhesive may be used to secure the two in place, and/or additional components may be used to secure the two together such as a clip or lock.

It is to be appreciated that oxygen is provided to the ventilator using an oxygen storage reservoir of the adaptor. It will be appreciated that a gas inlet is not a requirement of the adaptor, as the oxygen may be provided without the gas inlet present. In examples where the gas inlet is present, and oxygen is provided to the ventilator in preference to gas from the environment, it is to be appreciated that the gas inlet may enable gas from the environment to be provided when the demand for gas from the ventilator exceeds the supply provided by the oxygen inlet and the oxygen storage reservoir. In such situations, increased amounts of gas may be drawn in from the environment through the gas inlet.

Adaptors described herein have had a selected order of connection between the ventilator connection, the gas inlet, the oxygen connection (where relevant), and the oxygen storage reservoir. However, it is to be appreciated in the context of the present disclosure that such an arrangement is not to be considered limiting. Instead, the arrangement is selected to provide the desired flow characteristics within the adaptor, as well as between the adaptor and the ventilator. For example, the arrangement may be selected to enable flow of oxygen in preference to flow of gas from the environment. Likewise, the arrangements may be selected so that oxygen preferentially flows from the external oxygen source into the oxygen storage reservoir (e.g. either via the ventilator and fluid portal, or via the oxygen connection).

Adaptors described herein may be configured to enable oxygen to flow preferentially to air. For example, the flow of oxygen between (e.g. both to and from) the ventilator connection and the oxygen storage reservoir may be preferential to the flow between the ventilator connection and the gas inlet. Likewise, the flow of oxygen from the oxygen connection to the oxygen storage reservoir may be preferential to the flow of oxygen from the oxygen connection to the gas inlet. It is to be appreciated that the specific means for implementing this functionality is not to be considered limiting. Examples described herein may comprise an arrangement of the adaptor selected to provide such functionality, e.g. by providing different amounts of flow resistance (e.g. back pressure).

For example, one or more properties of the adaptor may be selected to provide this functionality. For example, the relevant portions of tubing (those connecting the reservoir and the ventilator connection/oxygen connection, and those connecting the gas inlet and the ventilator connection/oxygen connection) may have their properties selected accordingly.

Example properties include the length of the portions of tubing, the diameter or shape (e.g. the internal cross-sectional area of the tubing) of the portions of tubing, the material of the tubing (e.g. high/low friction), the path the tubing follows (e.g. straight or tortuous). Other features such as valves or other means for controlling fluid flow could be provided. For example, the gas inlet could be connected to the rest of the adaptor via a one-way valve.

The one-way valve may be openable in response to a control signal (e.g. to indicate greater gas requirements for the ventilator). A filter (e.g. a bacterial filter) provided proximal to the gas inlet may provide increased resistance to the flow of gas. Example filters include bacterial filters sold under the brand name Intersurgical (RTM), such as breathing filter, part# 1944000 Filta-Guard (RTM) by Intersurgical Ltd (RTM).

It will be appreciated from the discussion above that the examples shown in the figures are merely exemplary, and include features which may be generalised, removed or replaced as described herein and as set out in the claims. With reference to the drawings in general, it will be appreciated that schematic functional block diagrams are used to indicate functionality of systems and apparatus described herein. It will be appreciated however that the functionality need not be divided in this way, and should not be taken to imply any particular structure of hardware other than that described and claimed below. The function of one or more of the elements shown in the drawings may be further subdivided, and/or distributed throughout apparatus of the disclosure. In some examples the function of one or more elements shown in the drawings may be integrated into a single functional unit.

As will be appreciated by the skilled reader in the context of the present disclosure, each of the examples described herein may be implemented in a variety of different ways. Any feature of any aspects of the disclosure may be combined with any of the other aspects of the disclosure. For example method aspects may be combined with apparatus aspects, and features described with reference to the operation of particular elements of apparatus may be provided in methods which do not use those particular types of apparatus. In addition, each of the features of each of the examples is intended to be separable from the features which it is described in combination with, unless it is expressly stated that some other feature is essential to its operation. Each of these separable features may of course be combined with any of the other features of the examples in which it is described, or with any of the other features or combination of features of any of the other examples described herein. Furthermore, equivalents and modifications not described above may also be employed without departing from the invention.

It will be appreciated also that the apparatus and methods described herein aim to avoid wastage of oxygen supplied to the ventilator and do not cause or require to be caused any therapeutic effect to achieve such advantages. The supplied gas need not be oxygen. For example, embodiments of the disclosure may be connected to other passive gas management systems, such as those used in the supply of carbon dioxide in greenhouses and livestock management facilities. Other examples and variations of the disclosure will be apparent to the skilled addressee in the context of the present disclosure.

Claims

Claims 1. A method of increasing the oxygen efficiency of a ventilator, wherein the ventilator comprises a fluid portal connected to both (i) an oxygen storage reservoir and 00 a gas inlet for allowing gas from the atmosphere to flow to the fluid portal, and wherein the method comprises: collecting and storing oxygen in the oxygen storage reservoir connected to the fluid portal of the ventilator, wherein said oxygen is supplied to the ventilator by an oxygen supply from an external oxygen store; and providing the collected oxygen from the oxygen storage reservoir to the ventilator in preference to providing gas from the atmosphere received through the gas inlet.
2. The method of claim 1, wherein the oxygen storage reservoir and the gas inlet are connected to a ventilator connection configured for connection to the fluid portal of the ventilator.
3. The method of claim 2, wherein the oxygen storage reservoir is connected to the ventilator connection by a first portion of tubing, and wherein the gas inlet is connected to the ventilator connection by a second portion of tubing.
4. The method of claim 3, wherein a property of the first portion of tubing is different to a corresponding property of the second portion of tubing.
5. The method of claim 4, wherein the second portion of tubing is longer than the first portion of tubing.
6. The method of any preceding claim, wherein the connection between the fluid portal and the oxygen storage reservoir has a lower flow resistance to the flow of oxygen than the connection between the gas inlet and the fluid portal.
7. The method of any preceding claim, wherein the ventilator comprises an oxygen inlet configured to receive oxygen from the external oxygen store.
8. The method of claim 7, wherein some of the oxygen supplied to the ventilator through the oxygen inlet is vented through fluid portal and collected and stored in the oxygen storage reservoir.
9. The method of any of claims 7 or 8, wherein the ventilator receives both stored oxygen from the oxygen storage reservoir and supplied oxygen from the external oxygen store
10. The method of any of claims 1 to 6, wherein the external oxygen store is also connected to the fluid portal of the ventilator.
11. An adaptor for a ventilator, wherein the ventilator comprises: (i) an oxygen inlet for receiving oxygen from an external oxygen supply, and 00 a fluid portal for both discarding oxygen from the ventilator to the environment and for inputting gas from the environment for mixture with oxygen in the ventilator, wherein the adaptor comprises: an oxygen storage reservoir; and a ventilator connection connected to the oxygen storage reservoir, wherein the ventilator connection is configured to connect the adaptor to the fluid portal of a said ventilator to enable: (i) oxygen discarded from the ventilator through the fluid portal to be collected and stored in the oxygen storage reservoir, and (ii) oxygen collected in the oxygen storage reservoir to be provided to the ventilator.
12. An adaptor for a ventilator, wherein the ventilator comprises: (i) a fluid portal for receiving gas from the environment, wherein the adaptor comprises: an oxygen connection configured to connect the adaptor to an external oxygen supply; an oxygen storage reservoir connected to the oxygen connection to enable oxygen from the external oxygen supply to be collected and stored in the oxygen storage reservoir; and a ventilator connection connected to the oxygen connection and the oxygen storage reservoir, wherein the ventilator connection is configured to connect the adaptor to the fluid portal of a said ventilator to enable oxygen collected in the oxygen storage reservoir to be provided to the ventilator.
13. The adaptor of claims 11 or 12, wherein the adaptor further comprises a gas inlet for receiving gas from the environment.
14. The adaptor of claim 13, wherein the adaptor is arranged to enable oxygen from the oxygen storage reservoir to be input to the ventilator in preference to gas from the environment.
15. The adaptor of claims 13 or 14, wherein the connection between the oxygen storage reservoir and the ventilator connection has a lower flow resistance than the connection between the gas inlet and the ventilator connection thereby to provide a preferential flow of oxygen between the oxygen storage reservoir and the ventilator connection.
16. The adaptor of claim 15, wherein the connection between the oxygen storage reservoir and the ventilator connection comprises a first portion of tubing and the connection between the gas from the environment and the ventilator connection comprises a second portion of tubing; and wherein a property of the first portion of tubing is different to a corresponding property of the second portion of tubing thereby to provide the connection between the oxygen storage reservoir and the ventilator connection with a lower flow resistance than the connection between the gas from the environment and the ventilator connection.
17. The adaptor of claim 16, wherein the second portion of tubing is longer than the first portion of tubing.
18. The adaptor of claims 16 or 17, wherein at least one of the first and second portions of tubing is flexible and/or compressible.
19. The adaptor of any of claims 11 to 18, wherein the oxygen storage reservoir comprises an expandable portion.
20. The adaptor of any of claims 11 to 19, wherein the adaptor is made of a biocompatible material.
21. A ventilator comprising: a fluid portal; an oxygen storage reservoir connected to the fluid portal; and a gas inlet connected to the fluid portal, wherein the gas inlet is configured to receive gas from the atmosphere; wherein the ventilator is configured to: collect and store oxygen supplied from an external oxygen store in the oxygen storage reservoir; and provide oxygen collected in the oxygen storage reservoir to the ventilator in preference to providing gas from the atmosphere received through the gas inlet.
22. The ventilator of claim 21, wherein the ventilator further comprises an oxygen sensor configured to obtain an indication of an oxygen concentration of respirable gas output from the ventilator.
23. The ventilator of claim 22, wherein the ventilator is configured to output a control signal in the event that an obtained indication of oxygen concentration is not within a selected concentration range.
24. A method of modifying a ventilator, wherein the ventilator comprises: an oxygen inlet for receiving oxygen from an external oxygen supply; and a fluid portal for both discarding oxygen from the ventilator to the environment and for inputting gas from the environment for mixture with oxygen in the ventilator; wherein the method comprises modifying the ventilator so that: oxygen discarded through the fluid portal is collected and stored in an oxygen storage reservoir connected to the fluid portal; and oxygen collected in the oxygen storage reservoir is provided to the ventilator.
25. A method of modifying a ventilator, wherein the ventilator comprises a fluid portal for receiving gas from the environment, and wherein the method comprises modifying the ventilator so that: the ventilator is connected to both an external oxygen supply and an oxygen storage reservoir, wherein the oxygen storage reservoir is operable to collect and store oxygen supplied from the external oxygen supply; and oxygen collected in the oxygen storage reservoir is provided to the ventilator.