GB2117250A - Resuscitation training apparatus - Google Patents

Abstract

A resuscitation trainer 10 for teaching methods of external cardiac compression has a ball 22 compressible by the application of hand pressure to the chest part 16 to displace air. A vent 78 is formed in the chest part at the clinically correct position for cardiac compression such that with incorrectly positioned hands, the displaced air will be vented to the atmosphere and will not activate an indicator 80. Air ways can also be provided enabling a lung bag 92 above the chest part to be inflated by air blown into a mouth inlet 52 in simulated expired air resuscitation. <IMAGE>

Description

SPECIFICATION Resuscitation trainer This invention relates to resuscitation trainers which can be used to teach the correct methods of external cardiac compression (ECC).

Resuscitation trainers have been produced in the form of a replica of the human chest with an air bag which is compressed by the application of hand pressure in simulated ECC. It has been suggested that a gauge be connected with the air bag to measure air displacement and thus provide an indication of whether the correct technique is being employed.

In practical terms, there are three factors involved in correct ECC. These are the position of the hands, the amount of pressure applied and the frequency of application. The suggested use of a gauge enables the amount of applied pressure to be monitored and also - with suitable timing the frequency of application. The correct location of the hands must however be checked separately by the instructor.

It is an object of this invention to provide an improved resuscitation trainer which is of relatively simple construction yet capable of indicating whether hand pressure has been applied at the correct poSition.

Accordingly, the present invention consists in a resuscitation trainer comprising a chest part serving as a replica of the human chest and a pneumatic circuit including air displacement means operable through the application of hand pressure to the chest part in simulated external cardiac compression and indicator means arranged in the event of sufficient air displacement to indicate satisfactory cardiac compression, wherein the pneumatic circuit further includes a vent located in the chest part at the clinically correct position for the application of hand pressure, the pneumatic circuit being arranged such that sufficient air displacement is achievable at the indicator means only if the vent is covered by the hands.

Advantageously, the pneumatic circuit includes a bladder inflatable by displaced air to simulate a pulse.

Suitably, the pneumatic circuit includes a visual or audio indicator adapted to change state in the event of satisfactory cardiac compression.

Preferably, the air displacement means comprises a resiliently deformable ball compressible through movement of the chest part to displace air therefrom.

This invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a sectional view through a resuscitation trainer according to this invention, Figure 2 is a diagrammatic view of one pneumatic circuit of the trainer shown in Figure 1, and Figure 3 is a diagrammatic view of a second pneumatic circuit with certain mechanical elements of Figure 1 being shown in more detail.

There is shown in the drawings a resuscitation trainer which may be used to teach methods of both expired air resuscitation and external cardiac compression.

Referring initially to Figure 1, the trainer comprises a body 10 which is formed integrally from a suitable plastics material such as medium density polythene. The body 10 includes a generally flat back portion 12 from which a shoulder piece 14 extends upwardly to support a chest part 1 6 as a cantilever. The thickness and the properties of the plastics material used are chosen so that the chest part 1 6 is rigid but can flex at the shoulder piece 14 relative to the back portion. The upper surface of the chest part is contoured in the fashion of a rib cage and sternum. A body skin covering 18 extends over the body 10 and is removable for cleaning through a sliding clasp fastener -- not shown in the drawings.

Within what can be regarded as the chest cavity, a hollow platform 20 rises from the back portion 12 to support a resiliently deformable ball 22 which serves as an analogue of the heart. At the end remote from the shoulder piece 14, the back portion merges into an upright end wall 24, there being an outwardly opening pocket 26 formed at the junction of the back portion and end wall to form a housing for pipe connectors 28 and 30, the purpose of which will later be described in detail. Adjacent the shoulder piece, two lugs 32 extend downwardly from the back portion through respective openings in a flexible base plate 34.

Each lug 32 is formed with an aperture and a rod 36 passes through these aligned apertures to secure the body 10 to the base plate 34.

The head 40 of the trainer is formed in various parts. A skull piece 42 of realistic shape is pivotally connected to a hollow neck column 44 which extends through an oversize opening 46 in the body shoulder piece. A jaw member 48 is pivotally secured to the skull piece 42 close to the connection of the neck column. A iife-like moulded head skin 50 completely covers the skull piece and jaw member, the skin being formed with hair and eyes. At the position of the nose and mouth, the head skin carries an interior cup 52 which is sealed at its periphery to the head skin so as to collect air blown into the mouth or nose apertures.

This cup 52 is connected to one end of a throat tube 54 which passes through the hollow neck column. The head skin is secured to the jaw member by means of a small pin 56.

The throat tube 54 passing through the hollow neck column 44 terminates in a connector 58 which is a push fit in the end of the neck column.

The connector 58 is positioned within an aperture in the side of the platform 20 but this aperture is of a larger diameter than the connector so that relative movement is possible. Because of this and because of the fact that the aperture 46 in the shoulder piece through which the neck column passes is over size, the head is freely movable relative to the body. To prevent the head from being separated from the body, a plastics strip 60 is passed in a complete circle through an aperture 62 in the neck column and through apertures 64 in the end wall 24, where the two ends of the strip are connected in the pocket 26. This strip 60 has a degree of elasticity - it may for example be formed from plastics tube - and provides a realistic resistance to movement of the head.

The two pneumatic circuits of the trainer, a cardiac circuit and a lung circuit, will now be described.

Referring to Figure 2, the resiliently deformable ball 22 which serves as the heart analogue is connected through a T-piece 66 to a pipe 68 leading to the first external pipe connector 28. The remaining limb of the T-piece 66 is connected through a further pipe 70 to a small bladder 72 positioned between the neck column and the head skin to imitate the carotid pulse. A pipe 74 extends from the first external pipe connector 28 to a grommet 76 which is seated in a small hole 78 in the chest part 16.

In use the external pipe connector 28 may either be connected to an indicator unit as shown at 80 or, if such a unit is not available, may be closed by a bung. If the connector is closed, it will be seen that hand pressure on the chest part will cause it to move downwardly, flexing at the shoulder piece so compressing the resilient ball and displacing air therefrom. If the hands of the trainee are incorrectly positioned and do not cover the small hole 78 in the chest part, the displaced air will simply be vented to the atmosphere. If the hands are correctly positioned and the aperture is covered, the displaced air will inflate the bladder 72 giving an impression of a carotid pulse. With the indicator unit 80 connected, the displaced air from the ball can be used not only to inflate the bladder but also to operate a visual or audio indicator.A particularly useful form of indicator comprises a "dolls eye" element 82 which is rotated by the movement of air at the indicator unit to give the appearance of a "light" changing colour. This change in colour signifies correct technique and will only be achievable if the chest part is depressed a sufficient amount and the aperture covered. If insufficient pressure is applied or if the hands are incorrectly positioned, there will be no change of colour.

In the lung circuit of the trainer the connector 58 at the innermost end of the throat tube 54 communicates through a short pipe 84 to a one way valve 86 allowing the movement of air in a direction from the throat tube to the second external pipe connector 30 through a further pipe 84. Air returning to the one way valve along pipe 88 is not allowed to enter the throat tube but is exhausted to the chest cavity at 90. The second external pipe connector 30 communicates, additionally, with a pipe 90 leading to a flat lung bag 92 which lies on top of the chest part beneath the covering 1 8. As with the first pipe connector, the second pipe connector 30 may either be closed with a bung or connected to an indicating unit.

The lung bag 92 overlying the chest part does not prevent air from passing through the vent 78 if the hands are incorrectly positioned when practising ECC. Indeed, the lung bag helps in sealing the vent when the hands are positioned correctly.

In use of the trainer to illustrate expired air resuscitation techniques, the trainee is instructed to tilt the head backwardly to ensure that the air ways of the patient are not obstructed by the tongue. It will be seen from Figure 3 that in the normal position of the head the throat tube is kinked as it passes from the neck column 44 to the cup 52 and if the trainee fails to tilt the head backwardly, no air can be blown into the trainer.

Because of the way in which the head is connected to the body through an elastic retainer rather than through universal joints or the like, movement of the head offers a realistic "feel". The weight of the trainer is, however, considerably less than the weight of a human and if no further steps were taken in this regard, the realism of the trainer would be prejudiced. It is for this purpose that the body is connected through the tugs 32 and rod 36 to a flexible base plate 34. Tilting movement of the head can then only be achieved by flexing the base plate and the elasticity of this can be selected to offer a resistance to movement which mimics the weight of a human head.

Air blown into the mouth of the trainer with the nose aperture closed passes through the one-way valve and inflates the lung bag 92 giving a realistic rise in the chest of the trainer. It will be appreciated that other techniques of resuscitation, such as mouth-to-nose, can also be taught using the described trainer. In the case where the indicator unit is employed, the air passing through the second pipe connector can be used to operate a second "dolls eye" element 82.

The described resuscitation trainer has numerous advantages. It is a particulariy effective ECC teaching aid because an indication is provided of not only correct or incorrect pressure, but also of correct or incorrect hand position. The trainer is light in weight since it is produced almost entirely of plastics components. Despite its functional sophistication, the trainer is of simple construction and can readily be disassembled for the purposes of cleaning or minor repair. The fact that the lung bag is placed on top of the chest part is considered to be an important feature although not essential to the invention defined above -- since the chest part can then be formed integrally with the remainder of the body.

It should be understood that this invention has been described by way of example only and a variety of modifications are possible without departing from the scope of the invention.

Claims (12)

1. A resuscitation trainer comprising a chest part serving as a replica of the human chest and a pneumatic circuit including air displacement means operable through the application of hand pressure to the chest part in simulated external cardiac compression and indicator means arranged in the event of sufficient air displacement to indicate satisfactory cardiac compression, wherein the pneumatic circuit further includes a vent located in the chest part at the clinically correct position for the application of hand pressure, the pneumatic circuit being arranged such that sufficient air displacement is achievable at the indicator means only if the vent is covered by the hands.

2. A resuscitation trainer according to Claim 1, wherein the chest part comprises a substantially rigid chest plate mounted for limited movement in response to hand pressure.

3. A resuscitation trainer according to Claim 2, wherein the chest plate is supported as a cantilever upon an integral base portion.

4. A resuscitation trainer according to Claim 3, wherein said air displacement means comprises a resiliently deformable ball positioned between the chest part and the base portion so as to be compressed upon movement of the chest plate.

5. A resuscitation trainer according to any one of the preceding claims, wherein said indicator means comprises a bladder inflatable by displaced air to simulate a pulse.

6. A resuscitation trainer according to any one of Claims 1 to 4, wherein said indicator means comprises a visual or audio indicator adapted to change state in the event of satisfactory cardiac compression.

7. A resuscitation trainer according to any one of the preceding claims, further comprising a head part serving as a replica of the human head and a second pneumatic circuit including a mouth inlet provided in the head part and indicator means serving to indicate sufficient displacement of air in simulated expired air resuscitation.

8. A resuscitation trainer according to Claim 7, wherein said indicator means comprises an inflatable lung bag positioned above the chest part.

9. A resuscitation trainer according to Claim 7 or Claim 8, wherein said head part is connected to the chest part through resilient means enabling significant movement of the head part relatively to the chest part.

10. A resuscitation trainer according to Claim 9, wherein said chest part is secured to a base plate extending beneath the head part such that downward movement of the head part relatively to the chest part is achievable only with deformation of the base plate.

11. A resuscitation trainer according to any one of Claims 7 to 10, wherein said pneumatic circuit includes a passageway which is constricted in the normal position of the head part, the constriction being removable by downward movement of the head part relatively to the chest part.

12. A resuscitation trainer substantially as hereinbefore described with reference to and as shown in the accompanying drawings.