GB2473826A

GB2473826A - Respiratory device with valved monitoring port

Info

Publication number: GB2473826A
Application number: GB0916719A
Authority: GB
Inventors: Poormand Khashayar
Original assignee: Flexicare Medical Ltd
Current assignee: Flexicare Medical Ltd
Priority date: 2009-09-23
Filing date: 2009-09-23
Publication date: 2011-03-30
Anticipated expiration: 2029-09-23
Also published as: GB2473826B; GB0916719D0

Abstract

A respiratory device 10 comprises a body 12 defining an internal space having an inlet 14, an outlet 16, a monitoring port 20 with a valve 22 biased to a normally closed position, and a filter assembly 18 between the inlet and outlet ports. The valve 22 may have a pivotally hinged valve member 38 openable against the closing force of a biasing element 40 by an inserted tube such as a Luer tip 32 which may be sealed within the port by a seal 46. Various alternative types of one-way valves are also disclosed, including resiliently flexible blocking elements (28, fig 3a), which may additionally comprise tensioning elements (36, fig 4a) or a poppet-type arrangement (fig 6a).

Description

A Respiratory Device Gas delivery circuits for delivering anaesthetic or fresh gases from an anaesthetic machine or ventilator to a patient are commonly known as breathing systems or breathing circuits.

A breathing circuit generally comprises a closed or open loop circuit of conduits arranged to deliver gas from the anaesthetic machine or ventilator to the patient and to take away exhaled gases. Breathing circuits are also used in intensive care units (ICU). The term "breathing circuit" is used hereinafter to refer to all such systems or circuits.

In some cases a breathing circuit can be reused if a breathing circuit filter is provided in the circuit to protect the machine side of the circuit from contamination by exhaled gases.

Thus, a breathing circuit filter placed at the patient port of a breathing circuit may permit that breathing circuit to be reused a number of times. A breathing circuit filter generally comprises an inlet and an outlet with a filter assembly provided between them such that gasses passing from the inlet to the outlet pass through the filter assembly. A CO2 monitoring port is often provided on the outlet side (i.e. the machine side) of the breathing filter to permit a sample of filtered gas to be taken for analysis. Breathing circuits can also comprise other respiratory devices which include a monitoring port such as a CO2 monitoring port. Typically, known monitoring ports comprise a Luer lock port having a removably attachable cap, in some cases tethered to the port, such that when it is desired to monitor CO2 level in expired gas the cap is removed and subsequently replaced once monitoring is no longer required. The applicant has identified a number of potential problems with known breathing circuit filters and other devices and connectors where a CO2 monitoring port is incorporated. Firstly, it is possible that an untethered cap may become lost or, in cases where a tether is provided, the tether linking the cap to the port may become loose or break resulting in the possibility of the cap being lost. Secondly, upon removing the cap from the port, the port is open such that gases can escape Thirdly, the provision of a cap and tether will require additional attention to ensure it is properly closed to prevent any leakage.

According to a first aspect of the present invention there is provided a respiratory device comprising a body defining an internal space and having an inlet for fluid to enter the internal space and an outlet for fluid to exit the internal space, a monitoring port in fluid communication with the internal space, and a valve having an open configuration wherein fluid may pass through the port, from the internal space to the exterior of the respiratory device, and a closed configuration where the port is substantially sealed, wherein the valve is biased towards the closed configuration so as to substantially seal the port.

Thus, a respiratory device is provided having a valve that automatically closes the port in the absence of external factors, such as a CO2 monitoring Luer connector being used to open the valve. This may in some embodiments reduce the risk of gas leakage during connection and disconnection and may in some cases reduce the risk of a cap becoming disconnected and/or lost. The respiratory device may be suitable for use in an anaesthesia and/or ventilator breathing circuit.

The valve and/or port may be arranged such that in normal use the valve may only be changed from the closed to the open configuration when a CO2 monitoring Luer connector is sealingly coupled to the port.

Thus, in some embodiments the valve and/or port may be arranged such that an "airlock" type space is defined outside the valve, between the port and the CO2 monitoring Luer connector, which seals the space before the valve may be opened. This can in some cases reduce the likelihood of gas escaping from the device.

The valve may be arranged to inhibit fluid from entering the internal space via the port.

The respiratory device may include a filter assembly, arranged to filter a fluid flow path between the inlet and outlet, and the monitoring port may be in fluid communication with the internal space downstream of the filter.

The valve may comprise one or more resiliently flexible members deformable to change the valve between the close and open configurations. A resilient flexible member may be arranged to provide a seal between itself and a Luer tip when the latter is located within the port.

Thus, the valve itself may act to provide a seal with a male connector.

The port may include an engagement profile arranged to sealingly engage and lock with a connector, such as a Luer connector.

These and other aspects of the present invention will be apparent from and clarified with reference to the embodiments described herein.

Embodiments of the present invention will now be described, by way of non-limiting example only, with reference to the accompanying figures, in which: Figure 1 is a schematic cross-sectional view of a respiratory device according to an embodiment of the present invention; Figures 2a to 2d are schematic cross-sectional partial views of a port and valve of a respiratory device according to an embodiment of the present invention; Figures 3a to 3d are schematic cross-sectional partial views of a port and valve of a respiratory device according to a second embodiment of the present invention; Figures 4a to 4d are schematic cross-sectional partial views of a port and valve of a respiratory device according to a third embodiment of the present invention; Figures 5a to Sd are schematic cross-sectional partial views of a port and valve of a respiratory device according to a fourth embodiment of the present invention and Figures 6a and 6b are schematic cross-sectional partial views of a port and valve of a respiratory device according to a fifth embodiment of the present invention.

Figure 1 shows a respiratory device 10 according to an embodiment of the present invention. The respiratory device in the illustrated embodiment is a breathing filter, such as those used in anaesthesia breathing circuits. However, the term "respiratory device" is used to cover any part of a breathing circuit having an inlet, an outlet and a monitoring port such as a CO2 monitoring port. A non limiting list of examples of a respiratory device is: an Elbow; a catheter mount; a Y piece; and patient or machine end connectors.

The breathing filter 10 comprises a body 12 having an inlet 14, for incoming gas I to enter the breathing filter 10, and an outlet 16 for filtered gas 0 to leave the respiratory device 10.

The body 12 may take any suitable shape and/or configuration. A filter assembly 18 is provided between the inlet 14 and outlet 16 to filter incoming gas I to create filtered outgoing gas 0. The filter 10 may therefore be considered to have a space upstream or the filter assembly 18, where unfiltered gas is present, and a space downstream of the filter assembly 18, where filtered gas is present. The filter assembly 18 may comprise any suitable filer, such as a mechanical filter, an electrostatic filer, or the like. In some examples the filter assembly 18 may comprise a combination of two or more filters, of the same or different types. It will be appreciated that not all respiratory devices include a filter assembly.

The breathing circuit filter 10 further comprises a sampling/monitoring port 20 by which a sample of the filtered outgoing gas 0 may be taken, for example during operation of the breathing filter 10 within a breathing circuit. The port 20 may be a CO2 monitoring port.

The port 20 provides a fluid passageway between the outside of the filter 10 and the space within the filter that is downstream of the filter assembly 18. However, in other embodiments the port 20 may be arranged in fluid communication with other part of the internal space of the breathing filter 10, such as the space upstream of the filter. The port is arranged to be coupled to a sampling or monitoring device for taking a sample of filtered gas from the filter 10. A valve 22 is disposed within the bore of sampling port 20 and is arranged such that in a first configuration it inhibits fluid to flow from the outside of the housing 12 into the internal cavity of the filter via the port 20 and/or vice versa. The valve 22 is configured such that in a second configuration it permits fluid, such as filtered gas 0, within the breathing filter 10 to be withdrawn through the port 20. The withdrawn fluid sample may be conveyed by a suitable transport means, such as a sampling tube having a male connector for coupling to the port 20, to an analysis machine, such as a CO2 monitoring machine. The valve 22 is biased towards its first configuration such that it is normally closed. This reduces the likelihood of gas escaping from inside the filter in comparison to a tethered cap closure, which is could unintentionally be left open and may remain open until a person closes the port 20 using the cap.

Referring to Figures 2a to 2d, a first example of a valve 22a is shown, provided within the port 20 of the breathing filter 10 of Figure 1. The valve 22a comprises a blocking element 24 pivotally attached to the inside face of the port 20. In a closed configuration the general plane of the blocking element is substantially orthogonal to the axis of the port 20 so as to close it. The blocking element 24 can be pivoted away from the body 12 so as to open the port 20 and thus permit filtered gas 0 to be drawn out of the port 20, as illustrated in Figure 2b. A snug or the like is arranged to bias the blocking element towards a close position.

The valve 22a further comprises an abutment 26 arranged to inhibit the blocking element 24 from pivoting from the closed configuration inwards towards the body 12. Thus, when positive pressure is applied to the end of the port 20 furthest from the body, herein referred to as the "head" of the port 20, the valve 22a remains closed so as to prevent fluid from entering the body 12 via the port 20. This is illustrated in Figure 2c. A fluid sample may be withdrawn from the breathing filter 10 by connecting a sampling tube 28 to the port 20, as shown in Figure 2d, and arranging it such that the pressure at the "base" of the port 20, the base being the opposite end of the port 20 to the head, is greater than the pressure at the head by a sufficient degree to overcome the biasing force.

It should be noted that Figures 2a to 2d illustrate just one example of a valve 22a working in this way may be implemented and may other implementations will be apparent, such as a two-part blocking element, each part being pivotally attached to the port 20.

Referring to Figures 3a to 3d, a second example of a valve 22b is shown provided within the port 20 of a breathing filter 10 according to a second embodiment of the present invention. The valve 22b comprises a pair of resiliently flexible blocking elements 28.

The blocking elements are connected to the port 20 by reinforcing parts 30 arranged to carry the blocking elements such that they ordinarily inhibit the flow of incoming gas I and outgoing sample gas S through the port 20, as illustrated in Figures 3b and 3c respectively.

The valve 22 may be changed to an open configuration by way of a Luer tip 32, or the like, being inserted into the valve 22 from the outside of the body 12, thereby deforming the blocking elements 28 as illustrated in Figure 3d. The blocking elements 28 thus substantially provide a seal between the exterior of the Luer tip 32 and the interior of the port 20, so as to inhibit gas from entering or leaving the port 20 from outside the breathing filter 10. In some embodiments a seal may be provided between the port 20 and sampling device, for example by way of a Luer lock fitting provided between a Luer tip 32 and the port 20. Such Luer lock connectors are well known and therefore will not be described in detail. Where such a seal is provided, in some embodiments the valve is arranged such that it may only be changed from a closed to an open configuration when the seal is "made" between the port 20 and sampling device. In the case of a Luer lock connector, this may mean that the thread of the male port contacts the top of the port before the valve is opened by the male Luer tip and thereafter screwing the tip in seals the Luer connector and opens the valve 22.

This is just one example of how a valve 22b working in this way may be implemented and may other implementations will be apparent. For example, the valve may comprise more than two blocking elements, or in another example a single blocking element. In another example, the valve may have a single blocking element having a normally closed aperture formed therein that can be radially distended or otherwise deformed by a Luer tip or the like passing through it.

Referring to Figures 4a to 4d, a third example of a valve 22c is shown provided within the port 20 of a breathing filter 10 according to a third embodiment of the present invention.

The valve is similar in operation to the valve 22a of the first embodiment, described with reference to Figures 2a to 2d. However, the valve 22c of this example comprises a pair of resiliently flexible blocking members 34 arranged such that negative pressure applied to the head of the port 20 can deform them to permit withdrawal of sample gas 5, as shown in Figure 4b. The valve 22 further comprises tensioning elements 36 that slacken when sample gas S is withdrawn, but oppose the resiliently flexible blocking members 34 from flexing inwards when the head of the port 20 is positively pressured with respect to the base, as shown in Figure 4c. Any suitable element(s) may be provided to perform this function. End regions of the resiliently flexible blocking members 34 may however be inwardly deformed by a Luer tip 32 passing into the port 20, as shown in Figure 4d. Thus, the valve 22c of this example enables sample gas S to be withdrawn by way of negative pressure at the head of the port 20 and/or by a Luer tip 32 or the like passing into the port 20, yet substantially inhibits fluid from the environment outside the breathing filter 10 from entering via the port 20. The resiliently flexible blocking members 34 may in some embodiments sealingly contact the Luer tip 32. As with the embodiments described with reference to Figures 3a to 3d, in another embodiment a further seal may be provided, for example by way of a Luer lock fitting between the Luer tip 32 and the port 20 and in some cases the valve 22c may be arranged to open only after such a seal is made.

It should be noted that this is an example of how a valve 22c working in this way may be implemented and may other implementations will be apparent. For example, the valve may comprise more than two blocking elements, or in another example a single blocking element.

Referring to Figures 5a to 5d, a fourth example of a valve 22d is shown, provided within the port 20 of a breathing circuit filter 10 according to a fourth embodiment of the present invention. The valve 22d comprises a blocking element 38 pivotally attached to the port 20. In a closed configuration, as shown in Figures 5a and 5b, the blocking element substantially seals the port 20. An abutment 42 inhibits the blocking element 38 from pivoting outwardly beyond the closed configuration. A biasing element 40 is provided inward of the blocking element 38 to bias it towards the closed configuration. The biasing element should be arranged to inhibit the blocking element 38 from opening when positive pressure up to a threshold value is applied at the head of the port 20, as shown in Figure 5c.

The biasing means 40 is arranged to yield when pressure is applied above the threshold value, such as when a Luer tip 32 or the like is pressed against the blocking element 38.

This is illustrated in Figure 5d. A seal 46 may be provided to inhibit fluid from passing between the Luer tip 32 and the port 20. In some embodiments the seal may comprise a Luer lock fitting between the Luer tip 32 and the port 20. In some cases, the valve may be arranged such that it can only be opened by a particular sampling device once such a seal has been made.

Figure 6a shows a schematic cross-sectional partial view of a port 20 and valve of a respiratory device according to a fifth embodiment of the present invention. The port 20 in the illustrated embodiment defines a passageway between the inner space of the respiratory device and the outside environment. An upper portion 20a of the port has a smaller diameter than a lower portion 20c. A shoulder region 20b connects the upper 20a and lower 20c portions. A rigid base member 50 is mounted at the base of the port 20 in a fixed manner. The rigid base member 50 comprises a base plate 52 including one or more apertures (not shown) to permit fluid to flow from a first major side of the plate 52 to the opposing major side thereof. Put another way, the base plate permits fluid to flow through it between the interior space of the respiratory device and the outside environment, via the port 20. The rigid base member 50 further comprises spacing elements 54 arranged to define a support plane 54a spaced from the base plate 52. Consequently, the support elements 54 may support an object at the support plane 54a without the object in question covering and thus blocking the apertures formed through the base plate 52. A resiliently flexible valve member 56 is provided in the port 20 and arranged such that in its natural configuration shoulder regions 56a thereof abut against the neck portion 20b of the port 20 so as to provide a seal therebetween. Consequently, in its natural position, the sealing member 56 seals the passageway through the port 20.

As shown in Figure 6b, a force F applied to the head of the resiliently flexible valve member 56 may deform the valve member 56 such that its shoulder portion 56a moves out of contact with the neck portion 20b of the port so as to provide an open passageway 58 between the respective ends of the port 20. Consequently, sample fluid S, for example expired respiratory gases being channelled for the purpose of CO2 monitoring may pass through the apertures in the base plate 52 and through the opened passageway 58 and thereafter out of the port 20 to a connector, such as a Luer connector (not shown). Upon removal of the force F the resiliently flexible valve member 56 returns to its natural position, thereby sealing the port 20. The force F may be applied by the tip of a male connector, such as a Luer tip.

The port 20 and/or valve member 56 may be arranged such that a connector must be sealingly engaged with the port 20 before it can deform the valve 56 to a sufficient extent to open the passageway 58. It should be noted that the valve and port may together take any suitable configuration that enables a valve member to be moved or deformed between a sealed and unsealed configuration and many arrangements will be apparent to a skilled person. The resilient base member 50 may take any suitable form that enables the valve member 56 to be supported and deformed in use without it sealing apertures or the like to enable fluid to pass from the inner space of the respiratory device and into the port channel 20.

Claims

Claims 1. A respiratory device comprising: a body defining an internal space and having an inlet for fluid to enter the internal space and an outlet for fluid to exit the internal space; a monitoring port in fluid communication with the internal space; and a valve having an open configuration where a portion of fluid may pass through the port, from the internal space to the exterior of the respiratory device, and closed configuration where the port is substantially sealed, wherein the valve is biased towards the closed configuration so as to substantially seal the port.
2. A respiratory device according to claim 1, wherein the valve is arranged such that in normal use it may only be changed from the closed to the open configuration when a connector is sealingly coupled to the port.
3. A respiratory device according to any of claims 1 and 2, wherein the valve is arranged to inhibit fluid from entering the internal space via the port.
4. A respiratory device according to any preceding claim, further comprising a filter assembly arranged to filter a fluid flow path between the inlet and outlet, wherein the sampling port is in fluid communication with the internal space downstream of the filter assembly.
5. A respiratory device according to any preceding claim, wherein the valve comprises one or more resiliently flexible members deformable to change the valve between the closed and open configurations.
6. A respiratory device according to claim 5, wherein the resilient flexible member is arranged to provide a seal between itself and a connector when the latter is located within the port.
7. A respiratory device according to any preceding claim, wherein the port includes an engagement profile arranged to sealingly engage with a sampling device.
8. A respiratory device according to any preceding claim, wherein the inlet is arranged for gas to enter the internal space and/or the outlet is arranged for gas to exit the internal space and/or the port is arranged for the passageway of gas.
9. A respiratory device according to any preceding claim, wherein the respiratory device is suitable for use in an anaesthesia and/or ventilator breathing circuit.
10. A respiratory device substantially as herein described with reference to the accompanying drawings.