GB2176406A - Breathing aid - Google Patents

Abstract

A breathing aid for use in expired air resuscitation is described. It includes a conduit into which the rescuer blows at 15 and which is inserted into the patients mouth or nostril(s) at 3 and 4. A non-return valve protects the rescuer from infection from the patient. The non-return valve may be combined with an exhaust port 21 for exhausting air from the patient to atmosphere, or a separate exhaust port may be provided. <IMAGE>

Description

SPECIFICATION Breathing aid The present invention relates to breathing aids and particularly to devices for use in artificial respiration.

The resuscitation of patients who have stopped breathing is commonly carried out by the mouth-tomouth method of forced inhalation. It can be an effective method, but the operator is exposed to the risk of infection, especially by exhalations from the patient's (inflated) lungs, and by direct contact with the patient, particularly with saliva, blood or aspirated stomach contents, which present a substantial risk.

In accordance with the present invention, there is provided a device for use by an operator treating a patient by forced inhalation which comprises an air conduit having an outlet part shaped externally to penetrate and engage either the mouth or one or both nostrils of a patient and having an outlet for the passage of air into the mouth or nostril(s), an inlet for the passage of air exhaled from the mouth of an operator or from a resuscitator, and a non-return valve in the conduit operable substantially to prevent reverse flow of air from the outlet to the inlet. Preferably, between the valve and the outlet, there is an exhaust port for directing to atmosphere air exhaled from the patient.

In the use of the device, air blown from the operator's mouth or a resuscitator is forced through the outlet into the patient's mouth or nostril(s) and the operator or resuscitator is protected from a reverse airflow by the non-return valve. Exhalation from the patient flows outwardly to atmosphere either via the outlet and exhaust port if provided, or from whichever of the patients mouth and nose the device is not inserted in.

The outlet part preferably has an outer surface which converges in the direction of the outlet. With this form of outlet, an adequate fit is obtainable over a wide range of nostril dimensions. Best results are obtained when, as is preferred, at least the outlet part of the conduit is formed of a flexible resilient material. In an especially favoured construction the flexible resilient material has a wall thickness adequate to resist creasing, and to resist closure of the conduit if the device is being used in the patients mouth and the patient bites the conduit in spasm.

The position of the conduit adjacent the outlet is preferably bendable so as to provide an arrangement in which the course of approach to the nostril is non-critical and can be set, with curvature as required to suit the operator. This facility is of especial value in cases where device is inserted into the patient's nostrils and the operator would otherwise have difficulty in holding the patient's lips closed during the resuscitation.

The exhaust port may be associated with the non return valve, as illustrated more fully below. In an alternative arrangement the exhaust port may be a simple aperture in the wall of the conduit which the operator can close, as required, by the application of a finger.

Conveniently the valve is of the flexible diaphragm type. Such a valve has no moving parts other than the diaphragm and this moves only by flexure. The valve remains operable over long periods of storage.

In a particularly preferred embodiment, the valve and exhaust port are combined by the use of a diaphragm valve set on a freely movable diaphragm in a housing. By appropriate dimensioning of the parts, such a valve may be made to operate to seal the exhaust port, and allow the central diaphragm to open to allow passage of air from the operator or a resuscitator into the patient, and then, when the pressure of such air supply is removed, moving within the housing to open the exhaust ports. Such a valve gives a particularly reliable and simple construction, and has the major advantage that the exhaust port opens and closes automatically in use, thus facilitating use of the device by an operator.

Advantageously the conduit is provided in the form of a tubularfeed part connected with a separately formed outlet part. This arrangement enables the materials used in the construction to be chosen according to their required functions. Thus the outlet part can be constructed to provide the desired connection with the mouth or nostril(s) and to be flexible, and the tubular feed part can be constructed, if necessary of a different material, to resist accidental closure by bending.

The inlet may be any convenient shape enabling it to be used as a mouthpiece. A slightly tapering external profile is preferred, as this may conveniently be inserted into the outlet of a resuscitator tube, for the supply of air, oxygen enriched air or pure oxygen from a resuscitator. The taper is preferably a standard taper enabling fitting to be achieved with a wide variety of apparatus, the preferred standard tapers are 15 mm and 22 mm tapers in accordance with British standard BS3849.

Alternatively, an extension tube may be fitted on the inlet, which further protects the operator from exhalations from the patient.

A device having a single small outlet may be employed by fitting to one nostril and holding the other closed by finger-pressure. For simplicity of operation however, it is preferred to bifurcate the conduit towards the outlet to provide two similar outlet ports for simultaneous engagement with both nostrils of the patient. In a particularly preferred embodiment, a flange is provided around the conduit such that both such outlets may be inserted into a patients mouth with the flange either seating against the patient's lips from the outside or being located in the sulcus between lips and gums.

The invention is illustrated with reference to embodiments of the device shown in the accompanying drawings. In the drawings: Figure 1 shows one embodiment of the device in elevation, Figure 2 is a partial section through the device taken along lines 1111 of Figure 1, Figure 3 is an elevation taken in direction A of Figure 2, Figure 4 shows part of the device in cross section on an enlarged scale.

Figure 5 is a perspective view of an alternative embodiment, and Figure 6 is an axial section through the embodiment of Figure 5.

In the embodiment shown in Figures 1 to 4, a pair of conduits 1 and 2 having outlet parts 3 and 4 fitted into their ends 5 and 6 is provided in the form of a pair of branches extending from and formed integrally with a feed part 7. Conduits 1 and 2 and part 7 are all of generally cylindrical configuration, part 7 being of larger diameter than the others. An internal strengthening barrier 8 terminating at 9 extends from the junction of the conduits to divide part 7 into two passageways.

Conduits 1 and 2 and part 7 are in the form of a plasticised polymer moulding. The wall thickness of the conduits is such as to provide flexibility in use.

Part 7 has its flexibility reduced by barrier 8 and by having a greater wall thickness than conduits 1 and 2.

Outlet parts 3 and 4 are moulded from a softer plasticised polymer than conduits 1 and 2 and have a greater wall thickness, the parameters being chosen to provide an adequate seal by minor distortion when the parts are engaged within the nostril entrances of a patient. Their tapered configuration, shown in Figures 1 and 4, assists the engagement and allows for variations in nostril size.

Each outlet part is fitted with internal and external reinforcements 10 and 11 in the form of short lengths of tubing formed of the same grade of polymer as the outlet parts. These reinforcements stabilise the assembly in use.

Part 7 is connected by a rubber plug 12 of annular cross-section with a mouthpiece 13 formed of a pair of parts 14,15 of rigid resinous material. Part 15 penetrates part 14, as shown in Figure 2 to form an annular seating 16. This seating is bridged by cross members 17 radiating from a common centre at which there is provided a protuberance 18 upset at 19 to retain a valve disc 20 formed from flexible thermoplastic sheeting, e.g. polyethylene.

An air vent port 21 of such size as to be closed by covering with an operator's finger is provided in the wall of part 14 as shown.

In the use of the device the operator engages parts 3 and 4 with the patient's nostrils. For forced inhalation by blowing, port 21 is covered by a finger whilst blowing from the mouth through open end 22 of part 15, causing the outer parts of the valve disc 20 to be moved clear of the seating as shown by arrows 23 in Figure 2.

To permit exhalation, port 21 is uncovered, thus venting, to atmosphere, air returned from the patient. Valve disc 20 re-engages the seating and prevents substantial back-flow through end 22.

Such back-flow as takes place during the reengagement is a return of the operator's own exhaled air. The internal dimensions of the device provide an adequate return supply reservoir for this purpose.

Referring now to Figures 5 and 6, these show an alternative embodiment of the invention. It consists basically of two parts, a valve housing part 30, and an outlet moulding 40.

Moulding 40 consists essentially of a hollow tube made of a pliable and preferably transparent rubbery material which is bifurcated at one end into two short open tubes 41 and 42. These may be inserted into the nostrils of a patient, the flexibility of the material of manufacture, and the tapering shape of the tubes, enabling a close fit in the nostrils of the person. If the device is to be used in the mouth rather than the nostrils, then the whole of the portion of the device to the right of a flange 43, as seen in Figure 6, is inserted into the mouth of the patient, with flange 43 either held pressed against the outside of the lips or located between the gums and lips of the patient.As can clearly be seen in figure 6, in such a position, the portion of moulding 40 to the right of flange 43, extends generally downwards and lies hard against the upper surface of the tongue of the patient. With most patients, tubes 41 are then located right at the back of the tongue and pointing directly down into the throat.

Moulding 40 serves to hold the tongue in the correct position for resuscitation, and, more importantly, to provide an artificial airway making it impossible for the tongue or other parts of the mouth or pharynx to block the path of the air.

Part 30 is basically composed of two clear plastics mouldings preferably made of a rigid plastics such as polymethyl methacrylate or polycarbonate. The moulding consists basically of a mouthpiece portion 31, which is snap-fitted to an outlet portion 32.

Between portions 31 and 32 is defined a cage in which there is a loosely captive disc 34. That disc has a diaphragm 35 centrally mounted on it by means of a moulded pin 36. Adjacent diaphragm 35 are apertures 37 in disc 34. The assembly of parts 34 to 37 is so configured that parts 31 and 32 cannot be snap-fitted together unless the assembly is the right way round.

The outer portion of disc 34 can seat and seal on a plurality of exhaust apertures 38 moulded into part 32. In use of the device of figure 5 and 6, it is inserted into the mouth or nostrils as is explained above, and, optionally with the aid of an extension tube fitted to portion 31, air is exhaled by the operator into the device. The act of exhalation moves disc 34 slightly to the right, as shown in figure 6 to cover exhaust ports 38 while the edges of diaphragm 35 move away from disc 34, thus allowing flow of exhaled air through the disc apertures 37, through portion 32, moulding 40, and into the patient. When the operator sees that the patient's chest is inflated, he stops blowing. Immediately the back pressure from the patient moves disc 34 slightly to the left as shown in figure 6. Diaphragm 35 now seats firmly against disc 34 to close apertures 37, and prevent any exhalation from the patient passing into the mouthpiece 31, and the exhaust ports 38 are now uncovered, so that the patient's exhalations pass through moulding 40, and out of exhaust ports 38. A rib 45, moulded as part of portion 31, acts further to seal the mouthpiece from the exhalations of the patient.

At the end of the exhalation from the patient, the operator exhales into the mouthpiece again, and the process is repeated, until the patient starts breathing again of his own accord, or until attempts at expired air ventilation are discontinued, either because spontaneous breathing has recommenced, or because a manual or automatic ventilator/ resuscitator is brought into use, or because it is decided not to attempt further resuscitation.

Claims (11)

1. A device for use by an operator treating a patient by forced inhalation which comprises an air conduit having an outlet part shaped externally to penetrate and engage either the mouth, or one or both nostrils of a patient, and having an outlet for the passage of air into the mouth or nostril(s), an inlet for the passsage of air exhaled from the mouth of an operator or from a resuscitator, and a nonreturn valve in the conduit operable substantially to prevent reverse flow of air from the outlet to the inlet.

2. A device according to Claim 1 and including, between the valve and the outlet, an exhaust port for directing to atmosphere air exhaled from the patient.

3. A device according to Claim 1 or 2 wherein the outlet part has an outer surface which converges in the direction of the outlet.

4. A device according to any one of Claims 1 to 3 wherein at least the outlet part of the conduit is formed of a flexible resilient material.

5. A device according to any one of Claims 1 to 4 wherein the valve is of the flexible diaphragm type.

6. A device according to any one of Claims 1 to 5 wherein the valve is a diaphragm valve itself set on a moveable diaphragm, the moveable diaphragm acting to open or close one or more exhaust ports for exhausting to atmosphere exhalations from the patient.

7. A device according to any one of Claims 1 to 6 wherein the conduit is in theform of a tubular feed part connected with a separately formed outlet part.

8. A device according to any one of Claims 1 to 7 wherein the exterior of the conduit bears a flange adapted to seal against a patient's lips or between the lips and gums of a patient when the outlet part of the conduit is inserted into the mouth.

9. A device according to Claim 8 wherein the direction of the outlet part of the conduit relative to the flange is angled such that with the flange sealed against the lips of a patient or between the lips and gums of a patient, the outlet part acts to hold the tongue down with the outlet at the back of the tongue and adjacent the throat of the patient.

10. A device for use by an operator treating a patient by forced inhalation and substantially as hereinbefore described with reference to figures 1 to 4 of the accompanying drawings.

11. A device for use by an operator treating a patient by forced inhalation and substantially as hereinbefore described with reference to figures 5 and 6 of the accompanying drawings.