WO2012127193A1

WO2012127193A1 - Breathing device

Info

Publication number: WO2012127193A1
Application number: PCT/GB2012/000270
Authority: WO
Inventors: Christopher Alec GRACE
Original assignee: Grace Christopher Alec
Priority date: 2011-03-24
Filing date: 2012-03-26
Publication date: 2012-09-27
Also published as: GB2489275A; GB201104927D0

Abstract

The present invention provides an airway management device suitable for use by sufferers of obstructive sleep apnoea and which comprises a bifurcated airway body having a first nasal airway tube length and a second nasal airway tube length and a bridging portion, the first nasal airway tube length and the second nasal airway tube length being adapted to extend from a proximal end thereof seated externally at the entrance of a respective one of the user's nostrils through the nasal cavity to a distal end thereof opening into the oro-pharyngeal region of the user's mouth, the bridging portion linking together the proximal ends of the first nasal airway tube length and the second nasal airway tube length. The device not only has a greater airflow but also is inherently more stable and secure than existing naso-pharyngeal airway devices. Overall the device is not liable to dislodgement when sleeping and does not require use of any special anchoring arrangements at each end.

Description

Breathing Devices

Field of the Invention

The present invention concerns improvements in and relating to breathing devices and in particular airway management devices for use by sufferers of obstructive sleep apnoea (O.S.A.) to prevent the condition or alleviate the symptoms.

Background of the Invention

Obstructive sleep apnoea is a widespread medical condition that affects over a million individuals in the UK alone. In the condition, which is often exacerbated by obesity, a common cause is loss of muscle tone in the throat & oral tissues, particularly the soft palate, whereby the individual's breathing is interrupted and becomes very shallow during sleep. The breathing pauses can typically last between 10 and 20 seconds and can occur hundreds of times during a night. Jn extreme cases this can be lethal and even in mild cases will tend to cause fatigue and can lead to depression, diabetes, high blood pressure, transient ischemic attacks (TIA's), stroke and heart disease.

The traditional radical solution to address O.S.A entails surgery on the tissues of the airway obstruction to ablate them or improve muscle tone. However, more recently various orthodontic or mandibular devices have become available, designed primarily to alleviate snoring and these are generally adapted to be inserted in the mouth and function by mandibular advancement - pulling the tongue forwards and thereby opening the throat slightly improving ventilation of the superior airway but having no effect on the soft palate or nasal airways. These are not a comfortable or effective solution to O.S.A. ¹

A particularly commonly prescribed modern treatment for O.S.A. entails use of a continuous positive airway pressure (C.P.A.P.) machine to ventilate the user's airways. The treatment involves fitting a mask to a patient's face to supply pressurised air to the nose and/ or mouth of the patient from a pump machine at the patient's bedside. The air pressure is regulated to suit the individual user. While the use of C.P.A.P. produces an immediate improvement in sleep quality, the mask and the necessity of its being attached to the machine, is cumbersome & restricts movement during sleep. Due to apparatus cost, size and safety issues the C.P.A.P treatment is unsuited for widespread domestic use.

More recently others have developed devices that are simpler to manufacture and use, lightweight and compact and which are designed to be inserted into the nasal passageway. These are primarily known as naso-pharyngeal airway devices and an example of these is shown in PCT WO2010/113305. However, such devices tend comprise relatively hard plastics or rubber single tubes that tend to be somewhat unstable when fitted and in use unless anchored at one or both ends. In PCT WO2010/113305 it is proposed to have a ring at each end and optionally a balloon at the oro-pharyngeal end, whereas in US2010/0300450 the device has an inflatable supra-glottic laryngeal cuff. In such cases the device can only be safely fitted in place by a surgeon or by trained medical personnel, not self-administered.

Such medical safety considerations also apply to the various types of airway devices that are designed to reach well beyond the soft palate and right down to the epiglottis and trachea, such as the anaesthetic gas delivery device of US3867946; Those generally need to be installed under sedation/ anaesthesia and are not to be self-administered. Other airway devices are too short. The post-surgical airway device of US2009/0248058 that is for use after surgery to the nose is too short to serve for treatment of sleep apnoea, not reaching through to the soft palate of the user and serving only to keep open the upper nasal passageway where the surgery was done. US2006/0048775 has a short multipurpose single tube nasopharyngeal airway/ anaesthetic delivery and feeding device that is perforated through the wall of the tube and has a clip at one end to clip over the users nasal septum and with the perforations serving to direct fluid flow down the outside of the tube. US2008/0236591 has similarly overly short or overly long airway devices that are configured to couple to an artificial respirator, have airflow control valves and which are again wholly unsuitable for everyday use as a simple treatment for sleep apnoea.

It is an objective of the present invention to provide an airway management device suitable for use by sufferers of obstructive sleep apnoea (O.S.A.) and which has the simple to manufacture and use, lightweight and compact merits of the current nasopharyngeal airway devices but which provides enhanced airflow, better stability while being readily self-administered and which may be substantially more comfortable than most existing nasopharyngeal airway devices.

Summary of the Invention

According to a first aspect of the present invention there is provided an airway management device suitable for use by sufferers of obstructive sleep apnoea and which comprises a bifurcated airway body having a first nasal airway tube length and a second nasal airway tube length and a bridging portion, the first nasal airway tube length and the second nasal airway tube length being adapted to extend from a proximal end thereof seated externally at a mouth of a respective one of the user's nostrils through the nasal cavity to a distal end thereof opening into the oropharyngeal region of the user's mouth, the bridging portion linking together the proximal ends of the first nasal airway tube length and the second nasal airway tube length.

Preferably the bridging portion is thickened so that it is prominent relative to the proximal ends of the airway lengths to pass as a robust bridge over the septum of the nose while the proximal ends of the airway lengths remain approximately flush with the nostrils. The bridging portion is suitably of the order of 3mm thick or greater.

Because the device is bifurcated as described it thereby not only has a greater airflow but also is inherently more stable and secure than existing naso-pharyngeal airway devices. Overall the device is not liable to dislodgement when sleeping and does not require use of any special anchoring arrangements at each end.

Nevertheless, preferably the external ends of first nasal airway tube length and the second nasal airway tube length of the device are not only joined together by the bridging portion but also are each flared. Though the device is efficiently anchored against entry into the nasal passages by the existence of the bridging portion, the additional use of flared proximal ends of the tube lengths has the particular benefit of stopping any substantial airflow from passing around each tube length. This has been found to be particularly useful since we have found that otherwise the peripheral airflow can cause irritation of the nasal tissues and induce streams of mucus.

The first nasal airway tube length and the second nasal airway tube length are preferably both configured with an inherent curvature and which most preferably is in a shallow or flattened arc. The first nasal airway tube length and the second nasal airway tube length are suitably configured to extend substantially parallel to each other throughout their length whereby the device is substantially axi-symmetric and preferably are spaced apart by no more than about 5mm. Also it is preferred that the internal diameter of each of the nasal airway tube lengths is 5mm, or of the order of 4mm to 6mm.

Preferably the tubular wall of each airway tube length is of an elastomeric polymer that is 2mm or less and most preferably of the order of 1mm thick, whereby the tube remains soft and flexible for comfortable fitting and wearing but retains sufficient rigidity of tubular form that it will not be collapsed by irregular soft tissue formations of the nasal cavity or soft palate or localized vascular dilation and airway muscular constriction but will retain integrity as an airway. Presently preferred elastomeric polymers include silicone rubber and polychloroprene.

Suitably the external diameter of the distal end of each nasal airway tube length is of the order of 7mm where the internal diameter is 5mm. With flaring, external diameter of the proximal end of each nasal airway tube length is suitably of the order of double or more the external diameter of the distal end of each nasal airway tube length. In one preferred embodiment the external diameter of the flared proximal end is of the order of 18mm.

With minimal instruction the device of the present invention may be inserted by the user into his or her nasal cavities to reach through to just below the soft palate.

Unlike naso-tracheal cannulae that are fitted to hospital patients for assisted breathing during anaesthesia et cetera, the present device is relatively short and also relatively soft. It suitably reaches to just below the soft palate but not lower to the laryngeal inlet of the trachea (unlike the many laryngeal cuff terminated devices of the prior art) nor does it extend into the trachea. It does not obstruct the trachea or oro-pharyngeal tract and is also not liable to twist and kink as the patient turns their neck. The device is relatively soft and does not have the same level of tube reinforcement/ tubular rigidity as naso-tracheal cannulae. Indeed it can generally be softer than existing naso-pharyngeal airway devices because it is bifurcated and thereby has greater airflow and is inherently more stable and secure than the existing nasopharyngeal airway devices.

The softness of the device presents minimal risk of any tissue trauma/abrasion during installation and in use. As a result of these advantageous features the device can be readily self-administered, rather than requiring insertion by a surgeon or by trained medical personnel.

In a practical embodiment, that we have found to be suitable for an average adult male, the length of the device from end to end may be of the order of 160mm. The thickness of the tubular body is preferably of the order of 2mm at most and without need of any wire reinforcement or use of special strengthening polymers. Clear silicone or polychloroprene polymers are currently preferred alternative polymers from which the device may be moulded.

As the tubular lengths of the device pass through to the underside of the soft palate, they restrict vibration or movement of the soft palate. With the device in place, normal breathing through the nose is possible with the airway remaining unobstructed and the subject can move freely during sleep without fear of dislodging the device.

Brief Description of the Drawings

The invention will now be more particularly described, solely by way of example, with reference to the accompanying drawings in which:

Figure 1 is a front elevation view of an airway management device of the present invention;

Figure 2 is a side elevation view of the device;

Figure 3 is a longitudinal sectional view of the device showing the airway passage through the device ; and FFiigguurree 44 iiss aa sscchheemmaattiicc sseeccttiioonnaall vviieeww ooff aa uusseerr''ss hheeaadd sshhoowwiinngg tthhee ddeevviiccee iinn ssiittuu eexxtteennddiinngg tthhrroouugghh tthhee uusseerr''ss nnaassaall ccaavviittyy ttoo jjuusstt bbeeyyoonndd tthhee ssoofftt ppaallaattee aanndd tthhuuss pprroovviiddiinngg ffoorr uunniimmppeeddeedd aaiirrffllooww ttoo aanndd ffrroomm tthhee oorroo--pphhaarryynnxx..

Referring to the Figures, the preferred embodiment of the device is formed as a one piece moulding from an elastomer such as latex or more preferably a synthetic elastomer such as silicone or polychloroprene (a synthetic elastomer with similar attributes to natural rubber but without the associated danger of Type 1 protein allergies).

Both silicone elastomer and polychloroprene are suitable for injection moulding, the most practical & cost efficient process for the manufacture of this device. Both materials are suitably soft and pliable for this application and can withstand high temperatures (up to 137° C) for the purpose of sterilisation by hot water. Flushing with hot water and rinsing in baby bottle sterilising fluid are recommended after each use. These materials, in clear/ transparent form, will make apparent any deposits in the tubes.

The device comprises a bifurcated airway body 1 having a first nasal airway tube length 1a and a second nasal airway tube length 1b and a bridging portion 1c. The first nasal airway tube length 1 a and the second nasal airway tube length 1 b are adapted to extend from a proximal end that seats at the external entrance to a respective one of the user's nostrils through the nasal cavity to a distal end opening into the oro-pharyngeal region of the user's mouth. The bridging portion 1c links together the proximal ends of the first nasal airway tube length and the second nasal airway tube length and is thickened so that it is prominent relative to the proximal ends of the airway lengths. It forms a robust bridge over the septum of the user's nose while the proximal ends of the airway lengths remain approximately flush with the nostrils. The bridging portion is of the order of 3mm thick or greater.

The external proximal ends of first nasal airway tube length 1a and the second nasal airway tube length 1 b of the device 1 are not only joined together by the bridging portion 1c but also are each flared F. The flared proximal ends F provide a snug fit in the nostrils and allow easy unassisted normal breathing without inhaled or exhaled air bypassing the airway tubes of the device, which can create irritation.

The nose is the normal and natural entry point to the respiratory tract and the device of the present invention is designed specifically for the prevention or amelioration of sleep apnoea by fitting into the nostrils and with the airway lengths of the device passing to just beyond the soft palate to thereby provide a direct uninhibited airway to the major respiratory tract. The device can be inserted by the user with minimal instruction, a small amount of lubricating gel is recommended. Coughing and swallowing are not affected by the device which is unobtrusive and allows the user complete freedom of movement during sleep.

For a first fitting of the device the user may have it cut to a tailored size by a professional or may follow provided instructions to do so. In practice it is desirable to take a standard size of the device and insert it in a trial run and then tailor it to the individual user, shortening slightly by cutting off a small terminal portion of the airway lengths at the distal end. In some cases the trimming may also apply to the flared proximal ends too in order to render them as flush-fitting as possible. After the first fitting the user will not need any assistance to install the device in place for a good night's sleep. The trimming of the device is very straightforward and can be carried out by the user him/herself preferably with the aid of a mirror.

In summary, the device 1 comprises a pair of gently curved soft elastomeric tubes 1a, 1b that are flared at one end and at that end joined 1c at the top innermost edges. The whole device is moulded in one piece. On fitting, the tubes 1b, 1c are inserted into the nostrils and, being curved, naturally follow the path through the nasal passages over the soft palate into the top of the throat to just below the bottom skirt of the soft palate, thus preventing the soft palate moving/ blocking the nasal passages on exhalation ( apnoea ) or vibrating (snoring ). The substantially flush/ unobtrusive bridging portion 1c holds the whole device securely in place.

Claims

1. An airway management device suitable for use by sufferers of obstructive sleep apnoea and which comprises a bifurcated airway body having a first nasal airway tube length and a second nasal airway tube length and a bridging portion, the first nasal airway tube length and the second nasal airway tube length being adapted to extend from a proximal end thereof seated externally at the entrance of a respective one of the user's nostrils through the nasal cavity to a distal end thereof opening into the oro-pharyngeal region of the user's mouth at or proximate the soft palate and not extending down to the epiglottis, the bridging portion linking together the proximal ends of the first nasal airway tube length and the second nasal airway tube length.

2. An airway management device according to claim 1 , wherein the bridging portion is thickened so that it is prominent relative to the proximal ends of the airway lengths to pass as a robust bridge over the septum of the nose while the proximal ends of the airway lengths remain approximately flush with the nostrils..

3. An airway management device according to claim 1 or 2, wherein the external ends of first nasal airway tube length and the second nasal airway tube length of the device are not only joined together by the bridging portion but also are each flared.

4. An airway management device according to claim 1 , 2 or 3, wherein the first nasal airway tube length and the second nasal airway tube length are each configured with an inherent curvature.

5. An airway management device according to claim 1 , 2, 3 or 4, wherein the device is substantially axi-symmetric, the first nasal airway tube length and the second nasal airway tube length extending substantially parallel to each other throughout their length.

6. An airway management device according to any preceding claim, wherein the first nasal airway tube length and the second nasal airway tube length are spaced apart by no more than about 5mm.

7. An airway management device according to any preceding claim, wherein the internal diameter of each of the nasal airway tube lengths is of the order of 4mm to 6mm.

8. An airway management device according to any preceding claim, wherein the tubular wall of each airway tube length is of an elastomeric polymer that is 2mm or less thick.

9. An airway management device according to any preceding claim, wherein the tubular wall of each airway tube length is of an elastomeric polymer selected from silicone rubber and polychloroprene.

10. An airway management device according to claim 3, wherein with the flaring, the external diameter of the proximal end of each nasal airway tube length is of the order of double or more the external diameter of the distal end of each nasal airway tube length.

11 An airway management device according to any preceding claim and in use, wherein the device reaches to just below the soft palate of the user.

12 An airway management device according to any preceding claim, wherein the length of the device from end to end is of the order of 1 0mm to 170mm.

13. An airway management device according to any preceding claim, wherein the device is of a substantially transparent polymer.

14. An airway management device suitable for use by sufferers of obstructive sleep apnoea substantially as hereinbefore described with reference to the accompanying drawings.

15. A method of treating obstructive sleep apnoea which comprises providing an airway management device according to any preceding claim and inserting the nasal airway tubes, one into each of the user's nasal passages and lowering thereinto until halted by the bridging portion whereby the distal end thereof opens into the oro-pharyngeal region of the user's mouth at or proximate the soft palate and not extending down to the epiglottis.

16. A method as claimed in claim 15 wherein the tubes are trimmed to the required length for the user.