WO2010084183A2

WO2010084183A2 - Heated sleeve for respiratory conduit

Info

Publication number: WO2010084183A2
Application number: PCT/EP2010/050751
Authority: WO
Inventors: Jeno Kurja; Rik Julia Raoul Langerock; Neil Anthony Kaye; Malcolm Graham James
Original assignee: Plastiflex Belgium
Priority date: 2009-01-22
Filing date: 2010-01-22
Publication date: 2010-07-29
Also published as: WO2010084183A3

Abstract

A respiratory conduit heating system comprising a sleeve (1) in a flexible material provided for removably covering at least part of a respiratory conduit (12) of a respiratory system, or a liner (20) having a hollow tubular body (21) in a flexible material provided for being removably inserted into at least part of a respiratory conduit (12) of a respiratory system. The sleeve/liner comprises a heating element (3) and an interface (5) for connecting the heating element to a heat/power source (7).

Description

Heated sleeve for respiratory conduit

Technical field

The present invention relates to a respiratory conduit heating system according to the preamble of the first claim.

Background art

In a number of medical treatments, for instance during BiPAP, nPAP or CPAP treatment, an air flow is delivered directly from the room atmosphere to the patient through a conduit. As the air travels along the conduit, condensation may develop within the conduit (a phenomenon known as rainout). In order to increase patient comfort, the air flow is sometimes heated to some degree and humidified before being delivered to the patient. As the heated and humidified air travels along the conduit, the problem of rainout may become even greater. In fact, the temperature of the air may be too low to carry the water it contains as a vapour and some may condense.

In order to reduce condensation within the conduit, it is known to cover the conduit with an insulation fabric. However, such a system only reasonably functions if the room conditions are favourable, which is not always the case.

Other systems are known to avoid condensation within the conduit in which current heating wires are inherently integrated within or around the conduit or in the connecting cuffs and not made to be removable. For conduits which have to be periodically replaced, such as for example heated respiratory conduits, the heating system is each time thrown away together with the conduit, which leads to high replacement costs. Disclosure of the invention

It is an aim of the present invention to provide a cost-efficient reusable heating system to avoid the occurrence of condensation of water in a respiratory conduit system.

This aim is achieved with the heating system comprising all the technical characteristics of the independent claims.

According to the invention, a respiratory conduit heating system is provided which comprises a sleeve in a flexible material provided for removably covering at least part of a respiratory conduit of a respiratory system. The sleeve comprises a heating element and an interface for connecting the heating element to a heat source or a power source.

The heat generated in the sleeve by the heating element is able to warm the conduit and air (or any gas/vapour/fluid) passing through it to the required temperature. Compared to the insulation fabric known from the state of the art, the sleeve according to the present invention has the advantage that it is able to prevent condensation within the conduit, independent of the ambient conditions. When the ambient conditions are favourable it is possible that the insulation of the conduit by the sleeve, without additional heating or only a limited amount of heating, is sufficient to avoid condensation within the conduit. In unfavourable conditions, the heat generated in the sleeve by the heating element will be able to warm the conduit and any air passing through it to the required temperature. By maintaining the conduit at the correct temperature, condensation in the air flowing to the patient can be avoided. Moreover, the problem of rainout can be avoided, even if the air flow is heated and/or moisturized.

The heating system of the invention thus has the advantage that better control of the temperature of the breathable gas which is transported through the conduit can be achieved. In preferred embodiments, the heating element is an electric heating wire through which electricity is passed to generate heat, or a fluid channel for conducting a heating fluid, such as for instance water or air. However, the heating element can also be another type of heating element.

The incorporation of the heating element in the sleeve is preferably done in one of the following ways. The sleeve can for instance comprise two or more layers of fabric material, between which the heating element is provided. The heating element can also be incorporated into the fabric during manufacturing, for instance by weaving or knitting. The heating element may for instance also be stitched to the fabric. In alternative embodiments, the heating element can also be incorporated into a plastic film, or in any other flexible material known to the person skilled in the art.

The sleeve according to the invention can be easily removed from the conduit, by first disconnecting it from the power supply and then removing it from the conduit. When removed from the conduit, the sleeve can be washed and dried in accordance with the instructions, without the risk of damaging it. When dried, it is then easily put back over the conduit for use. In preferred embodiments, the heating element is an electric heating wire comprising NTC/PTC technology (Negative/Positive Temperature Coefficient). The NTC/PTC technology provides the system with a method of monitoring the temperature of the heating elements, in particular of the heating wires. As such, the incorporation of NTC/PTC technology increases the user safety of the patient.

A controller may be additionally provided between the heating element and the power source. The controller may for instance be used for controlling the temperature of the medium passing through the conduit and/or the amount of heating provided by the heating sleeve. The controller can be any type of controller considered suitable by the person skilled in the art and is preferably an independent controller which is reusable and not conduit system specific. The controller can be used to control the amount of heating provided by the heating element of the sleeve and as such, control the temperature within the conduit. In association with the above mentioned NTC/PTC technology, the controller is preferably provided for monitoring the temperature of the electric heating wire. PTC has the advantage that the system can be made self- regulating: increasing temperature leads to increased resistance, hence reduced current. NTC has the advantage that, since increased temperature leads to decreased resistance and further increased current, local hot spots can be detected. The controller is in such case preferably provided for recognizing any hot spot and shutting down the system if necessary.

In general, the main features/advantages of the respiratory conduit heating system according to the invention are:

- The respiratory conduit can be easily replaced or cleaned without having to change the heating system and vice versa.

- Condensation (rainout) within the air pathway of the conduit can be prevented, independent of the ambient conditions. - Constant improvement to patient comfort.

- The heating sleeve can be easily removed and cleaned without damaging it.

- In the embodiment with NTC/PTC technology, hot spot detection is enabled and patient safety can be increased. - The heating sleeve is an effective means to increase patient compliance.

- The heating sleeve offers a cost efficient means to avoid condensation within the fluid conduit. - The proposed system can operate with all currently known systems used in the treatment of Obstructive Sleep Apnoea/Hypopnoea Syndrome conditions.

- The system can operate independently of the Original Equipment Manufacturer's (OEM's) control systems if needed.

- The concept can be adapted to use with applicable nebulizers.

- The concept can be adapted to use with patient ventilation. Another embodiment of the invention is a respiratory conduit heating system comprising a liner having a hollow tubular body in a flexible material provided for being removably inserted into at least part of a respiratory conduit of a respiratory system. The liner comprises a heating element and an interface for connecting the heating element to a heat source or a power source.

In preferred embodiments, the heating element is an electric heating wire through which electricity is passed to generate heat, or a fluid channel for conducting a heating fluid, such as for instance water or air. However, the heating element can also be another type of heating element.

The liner can for example be a helically wound profile in a plastic material, the profile having a web portion and a rib portion, the heating element being incorporated into the rib portion. The technique of helically winding a plastic profile to form a corrugated flexible tubular body (the corrugations being formed by the rib of the helically wound profile) is well known in the art and hence needs no detailed description here. In such techniques, it is possible to make the rib hollow, so that a channel for transporting a heating fluid is formed, or to incorporate an electric heating wire in the rib.

In the case of an electric heating wire, the wire can again comprise NTC/PTC technology as described above for the sleeve. In case of a heating fluid, the interface for connecting the heating element to a heat source which supplies the heating fluid can be a tube for connecting the fluid channel on the liner to an appropriate outlet and inlet of the heat source, so that the fluid can circulate. In case of electric heating, the interface for connecting the heating element to a power source can be a cable for connecting the electric heating wire to an appropriate connector on the power source, so that a closed electric circuit is obtained. Either way, the tube or cable can be brought to the outside of the respiratory conduit by for example making a hole in one of the cuffs of the conduit, by which it is connected to for example a flow generator or a humidifier.

Brief description of the drawings

The invention will be further elucidated by means of the following description and the appended figures.

Figure 1 shows a preferred embodiment of the respiratory conduit heating system according to the present invention.

Figure 2 shows a preferred embodiment of a respiratory system including a respiratory conduit heating system according to the present invention.

Figures 3 and 4 show a preferred embodiment of another embodiment of respiratory conduit heating system according to the present invention.

The heating sleeve (1 ) shown in figure 1 comprises two fabric layers (2). An electric heating wire (3) is provided as a heating element between the two layers. The heating wire (3) shown in figure 1 has a hair bent shape extending over the entire length of the sleeve, but the shape can be adjusted as considered suitable by the person skilled in the art depending for instance on the type of conduit or treatment for which it is used. The sleeve is shown in opened position on figure 1 , but can be easily closed in tubular form around the respiratory conduit with the aid of the closure element (10). The closure element (10) may take any form considered suitable by the person skilled in the art, such as one or more zips, poppers, elastics, which may be one or more directional, or other appropriate methods.

In figure 1 , the heating wire of the sleeve is further connected with its electrical connection point (5) to a controller (6) with the aid of power supply means (9), the controller (6) being further connected to a power source (7) with the aid of power supply means (8). Instead of an electric heating wire (3), the heating element can also be a fluid channel for conducting a heating fluid such as water or air, which is then for example heated in a separate container as heat source, to which the fluid channel interfaces.

In use, the heating sleeve may enclose only part of the conduit or (preferably) the entire conduit.

In alternative embodiments, the sleeve (1 ) can be made from fabric materials or non-fabric materials such as for instance plastic materials or non-woven materials. The sleeve can be made of a non-elastic material, or potentially made of an elastic material, because this can simplify the application and removal of the sleeve to and from the conduit.

The sleeve can fit in various degrees of tightness around the conduit or a gap may be provided between the wall of the conduit and the sleeve, so as to ease the removal of the sleeve from the conduit. Preferably, the dimensions (length and diameter) of the sleeve are chosen in correspondence with the dimensions of the conduit, so that a snug fit and an efficient heat transfer can be achieved.

In figure 1 , the shape of the heating element (3) covers only about half of the fabric of the sleeve (1 ). This can of course vary, for example the whole of the sleeve (1 ) can be provided with parts of the heating element, though this is not essential. In alternative embodiments, the sleeve can be constructed with or without a closure system.

The heating element may be powered with any power source considered suitable by the person skilled in the art. The heating element may for instance be directly connected to the mains power supply, as shown in figure 1 and 2. Alternately the current may be supplied via a transformer (not shown) to reduce the voltage supplied to the heating wires. Alternatively it may be connected to a battery which forms the power source. The power supply can for example range from 6V to 240 V as required in different forms of the product.

In figure 2, the controller (6) is shown as a separate component of the system. The controller can however also be integrated in any device including (not limiting) flow generators and humidifiers, like the one (11 ) shown in figure 2 to which the conduit 12 is connected. Optionally, the heating sleeve (1 ) can be provided with a part (14) for covering at least part of the patient mask (13), as shown in figure 2. This part can for example be specifically shaped for this purpose.

The respiratory conduit heating system shown in figure 3 comprises a liner (20) having a hollow tubular body (21 ) in a flexible material provided for being removably inserted into at least part of a respiratory conduit of a respiratory system, like the one shown in figure 2. The hollow tubular body (21 ) is a helically wound profile in a plastic material, the profile having a web portion (24) and a rib portion (25) as shown in detail in cross section in figure 4. Adjacent windings are welded together as shown by the weld (26). The heating element (22) is an electric heating wire incorporated in the rib portion of the helically wound profile. An extended piece (23) of the electric heating wire functions as the interface for connecting the heating element to the electric power source. In use, this piece of wire is brought trough a hole which is made in the cuff of the respiratory conduit. In the embodiment of figure 4, the rib portion (25) is open towards the inside of the liner (20). The rib portion (25) may however also be closed towards the inside of the liner (20), so as to less obstruct the breathable gas flowing through the liner in use.

The heating sleeve and liner may be used in the treatment of animals as well as human therapy.

Claims

1. A respiratory conduit heating system comprising a sleeve (1 ) in a flexible material provided for removably covering at least part of a respiratory conduit (12) of a respiratory system, characterized in that the sleeve comprises a heating element (3) and an interface (5) for connecting the heating element to a heat/power source (7).

2. A respiratory conduit heating system according to claim 1 , wherein the heating element (3) is an electric heating wire.

3. A respiratory conduit heating system according to claim 1 , wherein the heating element (3) is a fluid channel for conducting a heating fluid.

4. A respiratory conduit heating system according to any one of the previous claims, wherein the heating element (3) has a hair bent shape extending over substantially the entire length of the sleeve.

5. A respiratory conduit heating system according to any one of the claims 1 -4, wherein the sleeve comprises two layers of fabric material (1 , 2) with the heating element (3) in between.

6. A respiratory conduit heating system according to any one of the claims 1 -4, wherein the flexible material of the sleeve is a fabric and the heating element is incorporated into the fabric.

7. A respiratory conduit according to claim 5 or 6, wherein the sleeve has a tubular form and the fabric material is elastic.

8. A respiratory conduit heating system according to any one of the previous claims, wherein the sleeve comprises a closure element (10) in longitudinal direction.

9. A respiratory conduit heating system according to any one of the previous claims, wherein the system further comprises a controller (6) for controlling the heating element (3).

10. A respiratory conduit heating system according to claim 9, wherein the heating element is an electric heating wire comprising NTC/PTC technology and the controller is provided for monitoring the temperature of the electric heating wire.

11. A respiratory system comprising a respiratory conduit (12) for supplying a breathable gas to a patient and a respiratory conduit heating system according to any one of the previous claims, wherein the sleeve (1 ) has dimensions corresponding to those of the respiratory conduit (12).

12. A respiratory system according to claim 11 , further comprising a patient mask (13) connectable to the respiratory conduit (12), wherein the sleeve has a part (14) which is provided for covering at least part of the mask (13).

13. A respiratory system according to claim 11 or 12, wherein the respiratory conduit is provided with fixing means for removably fixing the sleeve (1 ) on the conduit.

14. A respiratory system according to claim 13, wherein the fixing means comprise a velcro strip, provided for attaching a fabric layer of the sleeve.

15. A respiratory system according to claim 13, wherein the fixing means comprise snap fasteners, provided for fastening complementary snap fasteners provided on the sleeve.

16. A respiratory conduit heating system comprising a liner (20) having a hollow tubular body (21 ) in a flexible material provided for being removably inserted into at least part of a respiratory conduit (12) of a respiratory system, characterised in that the liner comprises a heating element (22) and an interface (23) for connecting the heating element to a heat source or a power source.

17. A respiratory conduit heating system according to claim 16, wherein the heating element is an electric heating wire.

18. A respiratory conduit heating system according to claim 16, wherein the heating element is a fluid channel for conducting a heating fluid.

19. A respiratory conduit heating system according to any one of the claims 16-18, wherein the hollow tubular body (21 ) is a helically wound profile in a plastic material having a web portion (24) and a rib portion (25), the heating element (22) being incorporated into the rib portion.

20. A respiratory system comprising a respiratory conduit (12) for supplying a breathable gas to a patient and a respiratory conduit heating system (20) according to any one of the previous claims, wherein the liner has dimensions corresponding to those of the respiratory conduit, such that the liner fits into the conduit.

21. A respiratory system according to claim 20, wherein the respiratory conduit (12) has a cuff for connection to another device, a hole being provided in the cuff through which the interface (23) of the liner is brought to the outside of the respiratory conduit.

22. A respiratory system according to any one of the claims 16-21 , wherein the heating element is an electric heating wire comprising NTC/PTC technology and a controller is provided for monitoring the temperature of the electric heating wire.