Dummy for practicing cardiopulmonary resuscitation (CPR) of a human being

What is claimed is:

1. A dummy for practicing cardiopulmonary resuscitation (CPR) of a human being, comprising a simulation of the thorax and the head, wherein the thorax simulation is formed by a hollow body of plastic material that has a through-opening and has an internal cavity that is in constant air exchange relationship with the atmosphere via the through-opening, so that the pneumatic pressure that exists within the cavity does not vary during the course of its use, and wherein the hollow body is of a wall thickness which is so selected that the compressibility and return force of the thorax simulation correspond to those of a human thorax.

2. A dummy as set forth in claim 1 wherein the wall thickness increases from the middle section corresponding to the sternum towards both sides.

3. A dummy as set forth in claim 1 wherein the hollow body has stiffening ribs the number and size of which are so selected that the compressibility and return force of the hollow body correspond to those of a human thorax.

4. A dummy as set forth in one of claim 1 wherein the hollow body has an upper portion with a thorax top side and a box-shaped lower portion.

5. A dummy as set forth in claim 1 wherein the hollow body has an extension as a neck simulation, to which the head is fixed.

6. A dummy for practicing cardiopulmonary resuscitation (CPR) of a human being, comprising a simulation of the thorax and the head, wherein the thorax simulation is formed by a blow-molded hollow body formed of plastic material, which is in air exchange relationship with the atmosphere and which is of a wall thickness which is so selected that the compressibility and return force of the thorax simulation correspond to those of a human thorax, wherein the hollow body has stiffening ribs in the form of rib-like beads on the wall of the hollow body, the number and size of which are so selected that the compressibility and return force of the hollow body correspond to those of a human thorax.

7. A dummy for practicing cardiopulmonary resuscitation (CPR) of a human being comprising:

a simulation of the thorax and the head formed by a hollow body of plastic material, which is in air exchange relationship with the atmosphere and which is of a wall thickness which is so selected that the compressibility and return force of the thorax simulation correspond to those of a human thorax; and

a cover formed of an elastically deformable material which covers the hollow body and which is releasably mounted to the hollow body and a bag for simulating the lungs disposed between the cover and the hollow body, wherein the elasticity of the cover determines the inflation resistance of the bag to approximate the inflation resistance of the human lungs.

8. A dummy as set forth in claim 7 wherein the cover has a top side which reproduces the form of the human upper body and has a relief configuration at least of the costal arch and the sternum.

9. A dummy as set forth in claim 7 wherein the lungs bag can be releasably fixed to the hollow body by an elastic fixing element located at an edge of the lungs bag.

10. A dummy as set forth in claim 9 wherein the fixing element is an elastic band which is fixed to the hollow body and which has a holding projection which can be inserted into a hole in the edge of the bag.

11. A dummy as set forth in claim 7 wherein the hollow body has an oppositely displaced longitudinal side and the cover is pivotably fixed to one side of the hollow body by a hinge and is releasably secured to the oppositely disposed longitudinal side of the hollow body.

12. A dummy as set forth in one of claim 7 wherein the cover has a projecting neck projection which in the closed condition of the cover covers the extension of the hollow body, wherein the trachea simulation of the lungs bag extends over the extension and under the neck projection, and wherein the lungs bag can be freely lifted out from the hollow body and the extension after the cover has been opened and the mandible removed.

13. A dummy for practicing cardiopulmonary resuscitation (CPR) of a human being, comprising a simulation of the thorax and the head, wherein the thorax simulation is formed by a hollow body of plastic material, which is in air exchange relationship with the atmosphere and which is of a wall thickness which is so selected that the compressibility and return force of the thorax simulation correspond to those of a human thorax, and wherein the hollow body has an extension as a neck simulation, to which the head is fixed and the head has two lateral resiliently outwardly bendable strip extensions and wherein respective elements of a resilient snap connection means are arranged on the neck extension and on the strip extensions.

14. A dummy as set forth in claim 13 further comprising laterally projecting pin projections are provided on the neck extension and provided on the strip extensions are openings to which the pin projections can engage to form a pivotal connection for the head to the hollow body.

15. A dummy for practicing cardiopulmonary resuscitation (CPR) of a human being, comprising:

a simulation of the thorax and the head, including the trachea, wherein the thorax simulation is formed by a hollow body of plastic material, which is in air exchange relationship with the atmosphere and which is of a wall thickness which is so selected that the compressibility and return force of the thorax simulation correspond to those of a human thorax: and

a mandible which is releasably fixed in the head and a holding means for releasably fixing an end portion of the trachea simulation, wherein the end portion of the trachea simulation is a valve housing of a non-return exhalation valve which in mouth-to-mouth resuscitation permits blowing into the lungs bag but which upon emptying of air from the inflated lungs bag diverts the flow of air into the interior of the head which is in air exchange relationship with the atmosphere.

16. A dummy as set forth in claim 15 wherein the holding means for the valve housing is provided on the releasable mandible.

17. A dummy as set forth in claim 16 wherein the valve housing has a connecting element and that in the condition of the valve housing of being inserted into the holding means the connecting element is freely accessible and can be coupled to a corresponding connecting element of a mask which simulates the face.

18. A dummy as set forth in claim 17 wherein the connecting element is a holding edge, which projects in a flange-like configuration, of a connecting portion and the connecting element of the mask is a tubular projection of an elastomeric material, which can be pressed on to the holding edge.

19. A dummy as set forth in claim 17 further comprising a mask and wherein the mask entirely consists of a soft elastomeric material.

20. A dummy as set forth in claim 16 wherein the lungs bag can be freely removed together with the mandible.

21. A dummy for practicing cardiopulmonary resuscitation (CPR) of a human being, comprising a simulation of the thorax and the head, wherein the thorax simulation is formed by a hollow body of plastic material, which is in air exchange relationship with the atmosphere and which is of a wall thickness which is so selected that the compressibility and return force of the thorax simulation correspond to those of a human thorax, and wherein the hollow body has at its underside an opening which is of such a size that the head can be pressed into and disposed in the interior of the hollow body, with elastic deformation of the edge of the opening.

22. A dummy for practicing cardiopulmonary resuscitation (CPR) of a human being, comprising a simulation of the thorax and the head, wherein the thorax simulation is formed by a hollow body of plastic material, which is in air exchange relationship with the atmosphere and which is of a wall thickness which is so selected that the compressibility and return force of the thorax simulation correspond to those of a human thorax, and wherein disposed interior of the hollow body is a mechanical sound generator which produces a sound signal at each sufficient compression of the thorax.

23. A dummy as set forth in claim 22 wherein the sound generator is releasably fixed to or can be reoriented with respect to the interior the chest wall of the hollow body.

Description Submit all comments and votes

FIELD OF THE INVENTION

The invention relates to a dummy for practicing cardiopulmonary resuscitation (CPR) of a human being.

BACKGROUND OF THE INVENTION

Satisfactory mastery of cardiopulmonary resuscitation (CPR) presupposes adequate training and frequent practice. For that purpose, many forms of dummies are known, which simulate the human upper body including head, to a greater or lesser degree, and which include a lungs simulation which can be the subject of artificial respiration through a mouth and/or nose opening. A significant factor in that respect is that the dummy behaves in a realistic fashion, both in heart massage and also in artificial respiration, that is to say it opposes a resistance to the compression to be performed in effecting heart massage, and experiences a deformation effect which substantially corresponds to the human thorax, while giving expansion of the thorax when artificial respiration is applied which substantially simulates thorax expansion when the lungs of a human being are filled. It is only when the dummy is fashioned to substantially simulate the behavior of the human body that cardiopulmonary resuscitation on such a dummy can be correlated to correct performance in an emergency situation on a human being, for example an accident casualty.

Numerous dummies for learning and practicing CPR are known, which, in a simulation of the human thorax, contain a resilient return element in the form of one or more springs or a pneumatic cylinder, wherein the resilient return element serves for simulation of the resistance which occurs when heart compression is effected, and for returning the thorax to its initial position. In such dummies the lungs are simulated by an inflatable bag which is communicated with the mouth or nose opening of the head by way of a trachea simulation.

A dummy is also already known in which the thorax is formed by an air-tight container which retains its shape and which at the same time forms the lungs and for that purpose is communicated with the mouth or nose opening of the head by way of a trachea simulation. In that arrangement the container is so designed that it simulates the thorax expansion which occurs upon artificial respiration by virtue of a resilient change in its shape, while also corresponding to the compression resistance of a human thorax when heart massage is performed (German patent specification No 2 543 671).

Just like the dummies referred to in the opening part of this specification, in which the thorax resistance is produced by mechanical or pneumatic springs, that known dummy also only provides a compromise, in terms of the behavior of the thorax in heart massage and in artificial respiration, because the air pressure which obtains in the interior of the airtight container is substantially determined by the resistance which occurs in heart massage, and the deformation characteristics involved. In that respect the container differs from the deformation characteristics of the human thorax in regard to its expansion characteristics when being inflated.

SUMMARY OF THE INVENTION

The primary object of the present invention is that of providing a dummy for learning and practicing CPR, which, without involving major technical expenditure, that is to say with a very simple configuration, provides for a function which greatly approaches the behavior of the human body, in heart massage and artificial respiration. This object and other objects of the invention are attained by the features of the invention as described herein.

In that respect the invention is based on the consideration that it is not only the extent of the deformation and compression resistance of the thorax in heart massage that are of significance, but also the nature and form of the deformation of the thorax represent a characteristic which should be approached as realistically as possible by the CPR dummy. For that reason the invention aims to provide features by virtue of the choice of the shape and the wall thickness of the hollow body which simulates the thorax. Particularly, the hollow body is designed so that it approximates the rib cage of the human upper body, not only in regard to its deformation resistance but also in regard to the nature of its deformation. For it is only in that way that the trainee acquires the feeling that the position of his or her hands is possibly not entirely correct with regard to the heart massage operation.

In certain embodiments of the present invention the hollow body simulating the thorax in the dummy is produced by a blow molding procedure. As a preferred configuration, stiffening ribs may be formed or molded in the shape of ridges or beads on the wall of the hollow body, which substantially simulate the human rib cage. In that arrangement the rib stiffness can be fairly accurately established by suitable dimensioning (depth and width) of the ridges or beads, to approximate to a human rib cage.

The invention is further based on the consideration that realistic simulation of the chest lifting movement when artificial respiration is effected presupposes the retention of the per se known lungs simulation by means of a flat bag. However, in order to be able to embody a realistic chest lifting movement, without adversely affecting the above-described deformation characteristics of the thorax, the invention provides a cover releasably mounted to the hollow body which simulates the thorax, which covers over the hollow body and which in certain preferred embodiments comprises a relatively soft, elastically stretchable material. The bag simulating the lungs is disposed between the cover and the thorax. In that arrangement the elastic stretchability of the cover is determined by suitable selection of the stretch properties of the material (for example, am elastomeric material) and by the choice of the wall thickness of the cover. (In one embodiment, the wall thickness increases from the middle, corresponding to the sternum, towards both sides.) Thus, this configuration determines the inflation resistance of the bag in a manner corresponding to the inflation resistance of the human lungs. In other words, the cover is substantially adapted in shape to the thorax simulation in the closed condition so that the uninflated lungs bag is arranged flat between the thorax and the cover. When effecting artificial respiration by inflation of the lungs bag, the bag lifts the cover, overcoming the stretch resistance thereof, with the thorax also being compressed downwardly to a slight degree. At the end of the respiration blow phase, the lungs bag is emptied again by the resilient return force of the cover.

Typically, the individual participants of an entire training group are usually successively trained on one dummy. Therefore, in addition to the features described above, it is also desirable to provide a CPR dummy which can be used by several individuals in a hygienic manner. In order to avoid the risk of infection, it is already known for those parts of the dummy which, when artificial respiration is being effected, come into contact with the mouth of the person performing the procedure, to be made interchangeable (see European Patent Publication No. A-396 799; U.S. Pat. No. 4,001,950). In addition a non-return exhalation valve provides that the air which is blown into the lungs simulation in a respiration blow does not go back to the mouth opening of the dummy when the lungs simulation is emptied, but is diverted into the open air (such as in the Laerdal `Resusci Anne`). As the non-return exhalation valve is necessarily arranged in the airway and the trachea simulation must be passed through the mouth or neck opening of the dummy, replacement of lungs simulations with a non-return exhalation valve of that kind is a comparatively difficult and time-consuming operation.

The invention therefore involves the further object of providing a trachea/lungs simulation for a dummy of the kind referred to herein which is of such a configuration that it can be easily replaced when changing to the next person to be trained. The invention further seeks to provide a trachea/lungs simulation of such a simple configuration that it can be thrown away after it has been used once. This object and other objects of the invention are attained by the features of the invention as described herein.

In the trachea/lungs simulation according to the invention, the bag simulating the lungs and the trachea and the non-return exhalation valve represent a unit which is easily interchangeably fixable as a whole in a dummy. In that arrangement the valve housing of the non-return exhalation valve is at the same time the fixing end portion for the trachea simulation in the head of the dummy. As a result, it is easily accessible through the mouth opening of the head. When using the above-mentioned cover and a per se known releasably disposed mandible simulation, it is now a simple matter for the entire trachea/lungs unit, with or without the valve, to be easily removed in a forward direction without the unit having to be drawn through any openings. It is only necessary to open the cover and lift the mandible simulation out of the mouth opening.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of a dummy according to the invention with the cover in the opened condition and without the lungs simulation;

FIG. 2 is a perspective cut-away view of the hollow body simulating the thorax of a dummy;

FIGS. 3a and 3b are views corresponding to that shown in FIG. 1 of a dummy according to the invention, without the cover, showing the arrangement of the lungs simulation, or a fixing band for the lungs simulation, on an enlarged scale;

FIG. 4 is a perspective view from below of the hollow body simulating the thorax, without the head;

FIG. 5 is a partly broken-way and sectional side view of the head and the neck portion of a dummy of the present invention;

FIG. 6 is a perspective view of a trachea/lungs simulation according to the invention;

FIGS. 7-9 are a plan view, a rear view and a side view of an interchangeable mandible of a dummy;

FIG. 10 is a view in axial section through the non-return valve;

FIG. 11 is a perspective view from below of a modification of the non-return valve in the exploded condition;

FIG. 12a is a view in axial section through a further modification of the non-return valve;

FIGS. 12b and 12c are perspective views of the valve housing and the filter housing of the modification shown in FIG. 12a;

FIG. 13 is a perspective view in longitudinal section of a third modification of the non-return valve;

FIG. 14 is a perspective view of a mechanical sound generator;

FIGS. 15a-15c show three different stages of deformation of the mechanical sound generator shown in FIG. 14; and

FIGS. 16a and 16b show a modified embodiment of the lungs bag with a pressure relief duct.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in the Figures, a preferred embodiment of the dummy according to the invention comprises a hollow body 1 with a hollow body upper portion 2, a hollow body lower portion 3, a cover 4 and a head 5. The hollow body upper portion 2 is substantially a reproduction of a human thorax in terms of its shape and in the region of the stomach portion has an opening 6 which approximately simulates the costal arch. The hollow body lower portion 3 is substantially box-shaped and in its lower wall includes a substantially square opening 8.

The hollow body 1 in the embodiment depicted in FIG. 1 is a one-piece blow molded component, for example of polypropylene, and in the hollow body upper portion 2 has a plurality of stiffening ribs 9 which simulate the human rib cage and which are formed by beads or ridges formed directly in the body in the blow molding operation. In order to substantially reproduce the deformation characteristics of the human rib cage, the depth of the beads or ridges and thus the height of the ribs increases from the thorax center 10 towards the sides. That results in a corresponding flexible stiffness of the ribs 9 in the oppositely disposed side regions of the hollow body upper portion 2 so that the compression characteristics in the central region 10 approximate those of a human thorax. Those compression characteristics are only determined by the mechanical properties of the hollow body upper portion 2 and the ribs 9 provided thereon; as there is a completely free interchange of air with the ambient atmosphere by way of the opening 8, no air pressure which would also be involved in determining the deformation phenomenon can be built up in the hollow body 1 when heart massage is effected.

The cover 4 comprises a relatively soft elastomeric material, for example PVC, which feels similar to the human skin and which accordingly provides the realistic feel of a human upper body. In addition the top side of the cover 4 (not shown in the drawing) is of a configuration having a relief which reproduces at least the costal arch and the sternum, and preferably also the ribs which extend from the sternum. In that way the trainee is given the necessary orientation in terms of the correct position at which heart massage is to be carried out. Fixed to the underside of the cover is a shaped or molded body 12 which is adapted in complementary fashion to the shape of the opening 6 and which comprises a softly yielding resilient material, for example foam. The shaped or molded body 12 can also be replaced by a spring means, for example a leaf spring. A curved neck projection 13 is formed on the cover 4 at the upper edge thereof.

The cover 4 is pivotably fixed on the side of the hollow body 1 by means of a hinge (not shown in FIG. 1), for example a film hinge, while at its opposite edge 14 (which is angled relative to the main surface of the cover 4) it has a fixing projection 15 with a number of holes 16. Corresponding to the holes 16 are projecting pins 17 on the hollow body lower portion 3, which engage into the holes 16 in the closed condition of the cover 4 and hold the cover in close contact with the top side of the hollow body 1 or a lungs bag 20 (see FIG. 3) disposed thereon. Because the cover 4 is made from the relatively soft elastomeric material and because the underside of the cover is substantially adapted in shape to the top side of the body 1 in the region of the ribs 9, the hollow body 1 and the cover 4 (in the closed condition) form a unit which behaves substantially like a unitary body when subjected to a loading force from above, as is applied when a heart massage operation is carried out.

In use, the lungs bag 20 lies fiat between the cover 4 and the hollow body 1. In order to secure it in position in relation to tensile forces which can be applied to the lungs bag 20 by movements of the head 5 which are described in greater detail hereinafter, the lungs bag 20 is held to the hollow body 1 by a fixing element 11, namely an elastic band. The elastic band 11 (see FIG. 3b) is provided with a respective stud or knob at one end on the top side and at the other end on the underside. The band 11 is fixed with the knob or stud at the underside, to a projection on the hollow body 1, which simulates the xiphoid process of the sternum; the other knob or stud can be engaged into a hole at the edge of the lungs bag 20. The edge region containing the hole is separated from the interior of the bag by an air-tight seam. If the lungs bag 20 is pulled for example towards the head by the above-mentioned pulling forces in use, the band 11 moves it back into its original position, after the tensile forces cease.

The underneath surface of the hollow body lower portion 3 carries four support elements 18, for example of rubber, which prevent the dummy from slipping on the ground. The hollow body 1 is also provided at its upper end with a neck projection 19 which is formed directly thereon or which is also subsequently fixed thereto, with lateral pins 21 which serve for releasably fixing the head 5, as will be described in greater detail hereinafter. The opening 8 in the hollow body 1 is of sufficient size to be able to dispose the removable head 5 through same, in the interior of the hollow body 1. In that way the amount of space required by the dummy in the course of transportation and the risk of damage to the head can be reduced. In that arrangement the dimensions of the opening 8 are so selected that the head 5 must be pushed into and removed again from the interior of the hollow body 1, with slight elastic deformation of the edges of the opening 8, because that prevents the head from accidentally falling out. The plastic material of the hollow body 1 permits such deformation.

The head 5 comprises a substantially skull-shaped plastic portion having a combined mouth and nose opening 51 and two lateral lug-shaped extensions 52 which each include a round opening 53. The rear side of the head 5 is open between the extensions 52. The head 5 comprises a flexibly elastic plastic material which permits the lateral extensions 52 to be bent apart to such an extent that they can be pushed over the pins 21 of the neck projection 19 on the hollow body 1. The openings 53 are so matched in terms of their diameter to the diameter of the pins 21 that the pins can snap into those openings when the head is pushed on to the neck projection 19. In that way the head 5 is pivotably secured to the hollow body 1 and can be released therefrom by bending the extensions 52 open again.

Provided at each of the oppositely disposed outward sides of the head 5 are projecting knobs or pins 54 which serve for fixing a mask 55 comprising, for example, soft elastomer (indicated by dashed lines in FIG. 5) which simulates the face.

In the interior of the mouth opening 51, at the two oppositely disposed side walls thereof, the head 5 carries projecting pivot and holding pins 56 which serve for releasably fixing and supporting a pivotable mandible 7. The face mask 55 extends beyond the mandible 7 and is also held by same.

Fixed on the top side of the neck projection 19 is an upwardly curved clip 57 whose curved rear co-operates with the mandible 7 upon pivotal movement thereof, together with the head 5, in a manner which is described hereinafter.

The mandible 7 is shown separately in FIGS. 7-9. It has a substantially horseshoe-shaped jaw portion 71, from each of the rearward ends of which a respective mounting projection 72 extends upwardly in an incline and is of such a configuration as to provide a rearwardly projecting mounting fork 73. The mounting fork 73 forms a mounting opening 74 with a local rounded-out portion, the diameter of which approximately corresponds to the diameter of the mounting pins 56. The jaw portion 71 comprises a flexible elastic plastic material which is elastically deformable to such an extent that it permits the mounting forks 73 to be pressed on to the mounting pins 56 and thus permits the mandible 7 to be fixed to the head 5. The two limbs of the jaw portion 71 are connected together adjacent the mounting projections 72 by a transverse strut 75 which has a rearwardly projecting clamping projection 76. Projecting upwardly from the top side of the transverse strut 75 is a pair of resilient holding arms 77 which have a circular recess 78 at their sides which face towards each other, and together form an elastic holding clip for a trachea/lungs simulation which is to be described in greater detail hereinafter.

FIG. 6 shows the trachea/lungs simulation which forms a self-contained handleable unit and comprises lungs bag 20 as a simulation for the lungs, a trachea simulation 25 which is to be integrally fitted to the bag 20, and a non-return exhalation valve 30. In FIG. 6, the length of the trachea simulation 25 is shown in shortened form. In actual fact the length is sufficient to permit the lungs bag 20 to be laid in the manner shown in FIG. 3 on the flat or shallowly concave topside of the hollow body 1, and provide communication with the non-return exhalation valve which is fixed in the mandible 7. The lungs bag 20 with the trachea 25 comprises a thin air-tight plastic foil. Lungs simulations of that kind are known and for that reason are not described in detail herein.

In the view shown in FIGS. 6 and 10, the non-return exhalation valve 30 comprises two injection-molded members which are fitted together, namely a connecting portion 31 and a trachea connection 32. The connecting portion 31 and trachea connection 32 can also be formed as a single integral unit. The connecting portion 31 is substantially cylindrical and at the upper end initially flares in a conical configuration and then extends in a flange-like form to provide a holding edge 33. At its lower end the connecting portion 31 has an air inlet opening 34 which at the lower edge forms a first valve seat 35 for a valve diaphragm 36 of silicone rubber.

The trachea connection 32 which is of a shallowly elliptical cross section has its longitudinal axis disposed approximately at a right angle to the longitudinal axis of the connecting portion 31 and has an air outlet opening 37 which is surrounded by a second valve seat 38 which projects into the interior. The valve seat 38 extends at an incline relative to the longitudinal axis of the trachea connection 32 in the manner shown in FIG. 10 so that its sealing plane defines an acute angle with the sealing plane of the first valve seat 35. The valve diaphragm 36 is fixed with a small pan of its circular periphery to the rearward end of the first valve seat 35 or to the underside of the connecting portion 31, for example by gluing. The connecting portion 31 and the trachea connection 32 together form a valve housing 39. The trachea simulation 25 is fixedly connected to the front end of the trachea connection 32, for example being glued or heat-sealed thereto.

When the dummy is ready for operation, the valve housing 39 is held by the holding clip 77 of the mandible 7 (see FIG. 5). For that purpose the valve housing is pressed into position between the holding arms of the holding clip 77 so that the arms initially elastically yield and then snap into position around the connecting portion 31, with the recesses 78 (see FIG. 8). The mandible 7 is then pushed with the mounting forks 73 on to the mounting pins 56 on the head 5. Lastly the face mask 55 which, in a known manner, has a tubular connection 59 which joins to the inside of the mouth opening is pushed with that connection on to the holding edge 33 of the connecting portion 31. As a result of the elastically yielding nature of the elastomeric material of the face mask 55 and the tubular connection 59 which is formed integrally therewith, the connection 59 is fitted air-tightly around the holding edge 33. In that way the valve housing 39 at the same time forms a connecting element for the face mask 55 and a part of its holding arrangement. In the pivotal position of the head 5 relative to the neck projection 19, as shown in FIG. 5, the trachea simulation 25 lies fiat on the curved back of the clip 57 and is squeezed together thereon by the clamping projection 76 on the transverse strut 75 of the mandible 7. In that position therefore air cannot be blown into the lungs bag 20, or it can be blown into the lungs bag only against a great deal of resistance. If on the other hand the head 5 is pivoted rearwardly by lifting at the mandible 7, as is also required for artificial respiration for a human being, the clamping projection 76 is pivoted away from the top side of the clip 57 so that the trachea simulation is freely available to carry a flow of air.

When the dummy is ready for operation, the lungs bag 20 lies on the hollow body in the manner shown in FIG. 3 and is held thereon by the closed cover 4 which is fixed by means of the holes 16 and the pins 17. In that arrangement the heart massage procedure can be practiced on the dummy from the top side of the cover, in which case the relief of the rib and sternum structure, which is to be found on the top side of the cover, gives the trainee the necessary reference point for correct positioning of the hands. If air is blown in through the mouth opening of the face mask 55, in the manner of mouth-to-mouth artificial respiration, it passes into the connecting portion 31 of the non-return exhalation valve 30, lifts the valve diaphragm 36 off the associated valve seat 35, flows through the trachea connection 32 and, when the head 5 is in the correct pivotal position, through the trachea simulation 25 and into the lungs bag 20. In that way the latter is expanded against the elastic resistance of the cover 4 so that the air pressure which is required to inflate the lungs bag 20 corresponds to the natural lungs resistance of a human being. Moreover expansion of the lungs bag 20 causes a lifting movement and expansion of the cover 4, which is clearly visible and in that respect realistic, so that the trainee can check the effectiveness of his mouth-to-mouth resuscitation procedure.

After conclusion of the practi