FR3115678A1 - Mechanical cardiac massage assist device - Google Patents

Abstract

The invention relates to a cardiac massage assistance device, with application to the field of first aid devices, comprising: - a compression assembly 1 positioned on the thorax, comprising a frame 5 in which a piston 4 translates along an axis of compression (Z), - flexible positioning means 2 connected to the frame, - manual actuation means comprising an arm 6, 7 having an actuation end 15, 16 and an opposite end 10, 11 connected to the frame by a pivot connection 12, 13, the piston having one end 8 that can be positioned against the thorax, and an opposite end 9 connected to the arm at a determined distance from the pivot connection. An action on the actuating end allows the piston to translate between a position of absence of pressure, and a position of pressure, on the thorax. Figure for the abstract: Figure 3

Description

Mechanical cardiac massage assist device

The present invention relates to a mechanical device for assisting cardiac massage, intended to facilitate the action of providing cardiac massage to a person. It finds an application in particular in the field of first aid devices, such as they can for example be used by a rescuer or a team of rescuers in intervention at the site of an accident with a person in cardio-respiratory arrest.

Performing cardiac massage is the first resuscitation action to be performed on a victim of cardiac arrest, pending the placement of a defibrillator which will briefly deliver an electric current and which is intended to restore normal heart rate.

Cardiac massage aims to replenish oxygen to the victim's organs such as the brain, the lungs, but above all the heart itself. Thus, when a person suffers a cardiac arrest, the practice of cardiac massage is imperative to maintain the chances of survival for the victim, and to reduce the level of sequelae.

The principle of cardiac massage is the application of a series of chest compressions. However, it is difficult to perform manual chest compressions correctly over an extended period of time. Not only does this gesture require great physical strength, but it also requires the ability to perform other tasks simultaneously, such as monitoring the patient's vital signs.

There are devices intended to automate the application of cardiac massage, equipped with control electronics, used for example in hospitals. Such devices typically include a compression unit mounted on a substantially rigid frame or support. The frame or support is positioned appropriately on and/or against the thorax of the subject on whom the cardiac massage is to be performed. The compression unit is then positioned against the subject's chest, at the exact position in which the massage is to be applied. The device is then started, controlled by the control electronics, for application of the cardiac massage by means of the compression unit.

Such a device can be used for example in a medical establishment. It can also be embarked in a vehicle by a team of rescuers in intervention, to go to the scene of an accident. However, in addition to the presence of the control electronics, this type of device has an overall rigidity and a weight which make it relatively difficult to handle and move, in particular during an intervention outside the establishment in which it is generally used. Thus, if the device has to be moved outside the intervention vehicle, or if the user has to carry the device on foot to the patient, for example when the vehicle cannot get close enough, the effort may prove painful and make the use of the device impractical.

Also, the cost of these devices, which are relatively heavy and carry a large amount of electronics, makes them unsuitable for equipping certain small structures.

In addition, these devices require a source of electrical energy and their operation therefore depends on it. This dependence creates a risk during the intervention of the rescuer, which can have an impact on the reliability of the product. In the event of an electronic failure, or a faulty battery for example, or if the latter is simply discharged, the user will not be able to use the device and therefore finds himself, with the only means, the manual practice of massage, in a conventional way.

Some known devices do not incorporate control electronics and/or do not require a source of electrical energy to perform cardiac massage. But these manual devices are usually tiring to use, especially after a while, even for someone with reasonable strength. However, certain cardiac massages must sometimes be applied for several minutes.

Manual devices of the pump or massage board type are also known. These devices accompany the rescuer in the practice of cardiac massage, but are not active.

One of the aims of the invention is therefore to solve in particular the aforementioned problems. Thus, the aim of the invention is in particular to propose a mechanical heart massage assistance device, which can be easily carried in a bag or a transport case by a rescuer in intervention at an accident site with a person in cardio-respiratory arrest, which is easy to use, and which reduces the effort required for the application of cardiac massage.

The invention thus relates to a mechanical device for assisting cardiac massage on a subject, comprising:

- a compression assembly configured to be positioned on the subject's thorax and apply a massage to said thorax, and comprising a frame (5) and at least one piston movable in guided translation in the frame along a compression axis,

- flexible positioning means connected to the frame and configured to allow the positioning and holding of the compression assembly against the subject's thorax,

- manual actuating means configured to engage pressure by the piston on the thorax of the subject and comprising at least one arm.

The arm has an actuating end and a first end opposite the actuating end and connected to the frame by a first pivot connection, the piston having a first end intended to be positioned against the subject's thorax, and a second end opposite its said first end and connected to the arm at an actuation point at a determined distance from said first pivot connection, so as to allow, by an action on the actuation end of the arm, the translation of the piston along the compression axis between a rest position in which, when the compression assembly is positioned by the flexible positioning means against the subject's thorax, the piston does not exert pressure on the subject's thorax, and a active position in which, when the compression assembly is positioned by the flexible positioning means against the subject's thorax, the piston exerts pressure on the subject's thorax.

According to certain embodiments, the device also comprises one or more of the following characteristics, taken separately or in all technically possible combinations:

• the actuating means comprise a second arm having an actuating end and a first end opposite the actuating end and connected to the frame by a first pivot connection, the second end of the piston being connected to the second arm at a second actuation point at a determined distance from the first pivot link corresponding to the determined distance separating the actuation point from the first pivot link from the other arm, so as to allow, by an action on each of the actuation ends respective positions of the two arms, the translation of the piston along the compression axis between a rest position in which, when the compression assembly is positioned by the flexible positioning means against the thorax of the subject, the piston does not exert no pressure on the subject's thorax, and an active position in which, when the compression assembly is positioned by the flexible positioning means against the thorax of the subject, the piston exerts pressure on the thorax of the subject;
• the respective actuation points of the two arms coincide;
• the frame comprises a fixed part and a free part in rotation around the compression axis, the piston being mounted so as to be able to rotate around the compression axis in the fixed part, and the respective first end(s) of the arm(s) being connected to the movable part by the respective first pivot connection(s), so as to allow the rotation of the arm(s) and of the piston around the compression axis;
• the second end of the piston is connected to the arm(s) at the point of actuation via a second pivot connection;
• the arm or arms are configured, at the actuation point, to be able to exert pressure on the second end of the piston along the compression axis when an action is exerted on the respective actuation end or ends of the arm ;
• the actuating means comprise, associated with each arm, an intermediate arm, a first end of which is connected to the frame by the corresponding first pivot connection, and of which a second end opposite its first end is connected to the first end of the corresponding arm by an intermediate pivot link;
• the positioning means comprise at least one strap, preferably two substantially parallel straps, each of the straps having two opposite ends connected to the frame, each of the straps being configured to surround the subject's thorax and hold the frame against the subject's thorax whatever either the perimeter of said thorax;
• the arm or arms comprise at least a first part including the actuation end of the corresponding arm, and at least a second part including the actuation point and the first end of the corresponding arm, said first part being foldable with respect to said second part ;
• the arm or arms comprise at least a first part including the actuation end of the corresponding arm, and at least a second part including the actuation point and the first end of the corresponding arm, said first part being telescopically retractable at least part in said second part.

Thus, the device of the invention is light, simple to install and easy to implement.

The flexible positioning means easily adapt to the thorax of adult or child subjects whose growth is sufficiently advanced, regardless of their morphology.

The device adapts easily to the position of the rescuer.

The device, which is entirely mechanical, does not require any external energy input other than the muscular strength of the user. In particular, it does not require batteries or pressurized air. It is therefore always and in all circumstances ready for use.

The arm or arms allow a reduction in the effort required to actuate the compression by the compression means. They are therefore very effective in considerably reducing the physical effort of the user who can then perform cardiac massage for a long period without further assistance. The reduction in physical power required is so great that even a frequency of 100 strokes per minute is possible throughout the duration of heart massage.

When the device is installed on a victim, the mechanical compressions are of constant force and depth. This controlled depth of pressure provides protection against ruptured ribs or other injuries, which can sometimes be caused by heart massage. The device therefore allows compressions to be performed neither too deeply nor too superficially.

In an emergency, every action must be the right one. The operation of the device of the invention is simple and intuitive. The movement of the arm(s) immediately initiates cardiac massage, and thus the resuscitation of the victim.

The flexible positioning means make it easy to prepare the subject for mechanical cardiac massage, with a practical fixing system which makes it possible to position the device very quickly (in less than 15 seconds).

The weight of the device is distributed over the positioning means, which take the form of a back belt, and not over a single point or a few specific points. The weight of the device has no influence on chest compressions/decompressions.

In addition, the device is preferably designed essentially in plastic material, and in aluminum. These materials ensure that there is no type of electrically conductive connection between the different parts of the device. Therefore, an electronic or electrical device, such as a defibrillator, can be used without removing the device of the invention from the patient. This makes it easier to continue cardiac massage after defibrillation with no lag or with extremely reduced lag.

The characteristics and advantages of the invention will appear on reading the following description, given solely by way of example, and not limiting, with reference to the following appended figures:

• Figure 1: schematic representation of an example of a device of the invention in position on a subject;
• Figure 2: schematic representation of an example of a device of the invention, in its variant with a single arm;
• Figure 3: schematic representation of the example of Figure 2, in its variant with two arms, with the piston of the compression assembly in the active position;
• figure 4: schematic representation of the variant of figure 3, in perspective
• figure 5: schematic representation of the variant of figure 3, with the piston of the compression assembly in the rest position
• Figure 6: schematic representation of the variant of Figure 3, with folding of part of one of the arms;
• Figure 7: schematic representation of the compression assembly of the example of Figure 3, in section;
• FIG. 8: schematic representation of another example of a device of the invention, in its variant with a single arm;
• Figure 9: schematic representation of the compression assembly of the example of Figure 8, in section;
• figure 10: schematic representation of the example of figure 8, in its variant with two arms;
• Figure 11: schematic representation of another example of a device of the invention, in its variant with a single arm;
• Figure 12: schematic representation of the compression assembly of the example of Figure 11, in section;
• figure 13: schematic representation of the example of figure 8, in its variant with two arms;
• Figure 14: schematic representation of another example of a device of the invention, in its variant with two arms;
• Figure 15: schematic representation of another example of a device of the invention, in its variant with two arms;
• figure 16: schematic representation of the example of figures 3 to 6, with highlighting of the actuation of the arms.

The figures show various examples of embodiment of the device of the invention, in position ( ) or not (figures 2 to 16) on a subject, with a single arm (figures 2, 8, 9, 11, 12), two arms (figures 1, 3 to 6, 10, 13 to 16), or a number arm indeterminate ( ).

The device comprises a compression assembly 1 configured to be positioned on the subject's thorax and to apply a massage thereto, flexible positioning means 2 configured to make it possible to position and hold the compression assembly 1 against the subject's thorax , and actuating means configured to engage pressure by the compression means 1, specifically by a piston 4, on the subject's thorax.

The compression assembly 1 comprises a frame 5 and at least the previously mentioned piston 4. This piston 4 is movable in guided translation in the frame 5 along a compression axis (Z).

When the device is in position against the thorax of the subject lying on his back on a substantially horizontal surface, such as in the example of , this compression axis (Z) is substantially vertical.

The flexible positioning means 2 are connected to the frame 5 of the compression assembly 1.

The 3 manual actuating means include one or more arms. Specifically, in the examples shown in the various figures, the actuating means comprise a single arm 6, or two arms 6 and 7.

The arm or arms each have an actuation end and a first end opposite the actuation end. Thus, the arm 6 has an actuating end 15, and a first end 10 opposite the actuating end 15, and the arm 7 has an actuating end 16 and a first end 11 opposite the end of actuation 16.

As can be seen for example in Figures 1 to 6, the respective actuating end or ends 15, 16 of the arm or arms 6, 7 take the form of a gripping means, such as a handle, intended to be entered by the user to actuate the arm(s) 6, 7.

The actuating end of each of the arms is connected to the frame 5 by a first pivot connection. Thus, the first end 10 of the arm 6 is connected to the frame 5 by a first pivot connection 12, and the first end 11 of the arm 7 is connected to the frame 5 by a corresponding first pivot connection 13.

Thus, the action of the user on the arm(s) 6, 7, via the corresponding actuating end 15, 16, causes the rotation of the arm(s) 6, 7 around the axis of the first pivot link. corresponding 12, 13.

The piston 4 has a first end 8 intended to be positioned against the thorax of the subject, and a second end 9 opposite this first end 8. The second end 9 is connected to the arm(s) 6, 7 at an actuation point . To simplify the figures, this actuation point bears the same numerical reference 9 as the second end 9 of the piston 4. This actuation point 9 is located at a determined distance from the corresponding first pivot connection 12, 13.

The action of the user on the arm or arms 6, 7, via the corresponding actuation end 15, 16, causes the actuation of the piston 4 via the actuation point 9.

Thus, an action of the user on the actuating end 15, 16 of the corresponding arm 6, 7, causes the translation of the piston 4 along the compression axis (Z). The piston runs between a rest position shown for example on the , and an active position represented for example on the .

When the compression assembly 1 is positioned by the flexible positioning means 2 against the subject's thorax (see ), in the rest position, the piston 4 does not exert pressure on the subject's thorax. The first end 8 of the piston 4, through which the pressure is exerted on the subject, is then against the, or close to, the frame 5.

Always when the compression assembly 1 is positioned by the flexible positioning means 2 against the subject's thorax (see ), but this time in the active position, the piston 4 exerts pressure on the subject's thorax. The first end 8 of the piston 4, through which the pressure is exerted on the subject, is then at a distance from the frame 5.

As shown on the , based on the embodiment of Figures 3 to 6, the arm or arms 6, 7 therefore act as levers, making it possible to amplify the force exerted by the user on the actuating end or ends 15, 16 .

To produce a force F2 at the actuating end 15 of the arm or lever 6, the user must provide a force F1 at the actuating end 15 of this lever 6, driving the lever 6 in rotation R around the axis passing through the actuation point 9. This force F1 provided by the user verifies the law of levers: F1 × d1 = F2 × d2, where d1 represents the distance between the actuation point 9 and the end d actuation 15 of lever 6, and d2 represents the distance between actuation point 9 and first end 10 of lever 6.

This distance d2 corresponds substantially to the determined distance mentioned above (that is to say the distance between the actuation point and the first pivot link 12), when there is no intermediate pivot link 20 for the connection of the lever 6 with the frame 5, as will be seen in the embodiments illustrated in FIGS. 8 to 15. When this intermediate pivot connection 20 is present, that is to say when the intermediate arm 19a is present, or when the point of connection of the end of the arm with the frame 5 is offset with respect to the longitudinal axis of the arm (see for example figures 11 to 13), the distance d2 is almost identical to the determined distance mentioned above, the relationship between d2 and this determined distance then being a function of the length of the intermediate arm 19a or of the shape and dimension of the offset mentioned above.

We therefore obtain F1=d2/d1*F2, and thus a reduction in the force F1 to be applied at the actuation end 15 to obtain the force F2 at the actuation point 9, as a function of the distance ratio d2/ d1.

All of these considerations apply of course to the second arm or lever 7 and to the corresponding elements.

Preferably, as illustrated in each of the examples in which two actuation arms 6, 7 are present, the respective actuation points 9 of the two arms 6, 7 coincide.

Specifically, these two actuation points 9 are on the same actuation axis perpendicular to the compression axis (Z). But they are offset, for example inside a yoke 36, along this actuation axis. By misuse of language, as their respective actuation axes are confused, they are said to be confused. Consequently, it will be said that these two actuation points 9 are not coincident, when their respective actuation axes are not coincident. This is the case in the example of the , which will be described later.

As can be seen for example in Figures 7, 9, and 12, and partly in the , the frame 5 comprises a fixed part 17, 18, 51, 55 and a part 50 free to rotate about the compression axis (Z).

The piston 4 is mounted in the fixed part, mobile in rotation around the compression axis (Z), for example via one or more bearings 54, preferably smooth. In the example represented in particular on the , two bearings are provided, one, referenced 54, in the lower part, and the other, not referenced, in the upper part. The respective first end(s) 10, 11 of the arm(s) 6, 7 are connected to the movable part 50, by the respective first pivot link(s) 12, 13.

The mobile part 50, therefore the arm or arms 6, 7, as well as the piston 4, can therefore rotate around the compression axis (Z). This has the particular advantage of allowing the orientation of the actuating arms 6, 7 to be varied around the compression axis (Z), thus allowing the user to position himself in different ways with respect to the subject.

By way of example, as shown in Figures 7, 9 and 12, the fixed part of the frame 5 comprises a central part 18 in which the piston 4 is mounted, as explained above. The fixed central part 18 is mounted in a lower cover 17, closed by a plate or sole 55. The cover 17, the central part 18 and the movable part 50 of the frame 5, are clamped by a flange 51 fixed through this cover. 17 and this central part 18 by means of fixing elements 53, such as screws 53, through inserts 52. Thus, the plate 55, cover 17, central part 18 and flange 51 assembly forms the part frame 5. The flange 51 blocks a pivot piece 50 housed in the movable part 18.

The first end 8 of the pivot 4 takes the form of an added piece 8, fixed in the axis of the piston 4, for example by a fixing element 56.

The second end 9 of the pivot takes the form of a yoke 36 fixed in the axis of the piston 4, for example by a fixing element not referenced but analogous to the fixing element 56.

As shown in all of the figures, except in the embodiment of the , the second end 9 of the piston 4 is connected to the single arm 6, or to the two arms 6, 7, at the actuation point 9 via a second pivot connection 9. As a reminder, the points d actuation for the two arms 6 and 7 preferably coincide at the actuation point 9 (see above).

Alternatively, as shown in , the arm or arms 6, 7 are configured, at the level of the actuation point 9 (or of their respective actuation points when they are not coincident) to be able to exert pressure on the second end 9 of the piston 4 according to the compression axis (Z), when an action is exerted on the actuating end 15 or on the respective actuating ends 15, 16 of the arm(s) 6, 7.

In the example of the , a protrusion 60 in each of the arms 6, 7 at the actuation point 9 presses on the second end of the piston 4 which is configured to receive the pressure from the aforementioned protrusions 60, for example with a curved surface 39.

As mentioned above, the connection between the arm(s) 6, 7 and the frame 5 can be made by an intermediate arm, as illustrated in the examples of FIGS. 2 to 6. Thus, the arm 6 is connected to the frame 5 via the intermediate arm 19a, and arm 7 is connected to frame 5 via intermediate arm 19b.

A first end of the or each intermediate arm 19a, 19b is connected to the frame 5 by the corresponding first pivot connection 12, 13. A second end of the or each intermediate arm 19a, 19b, opposite the corresponding first end, is connected to the first end 10, 11 of the corresponding arm 6, 7 by an intermediate pivot connection 20, 21.

Thus, the first end of the intermediate arm 19a is connected to the frame 5 by the first pivot connection 12, and its opposite second end is connected to the first end 10 of the arm 6. Similarly, the first end of the intermediate arm 19b is connected to the chassis 5 by the first pivot connection 13, and its opposite second end is connected to the first end 11 of the arm 7.

As can be seen in the various examples shown in the figures, the positioning means 2 comprise at least one strap, preferably two straps 28, 29 substantially parallel.

Each of the straps 28, 29 has two opposite ends connected to the frame 5, and are configured to surround the subject's thorax and hold the frame 5 against the subject's thorax regardless of the perimeter of this thorax.

In the examples shown (see for example the ), the frame 5 is equipped with attachment means 30, and each of the ends of the straps 28, 29 comprises attachment elements 26, 27 which make it possible to attach the straps 28, 29 to the attachment means 30, therefore to the frame 5, by adjusting the length, therefore the perimeter formed by the straps 28, 29.

In a variant embodiment, which can be applied to all embodiments, the arm(s) 6, 7 are foldable.

Specifically, the arm 6 comprises at least a first part 22 including the actuation end 15, and at least a second part 24 including the actuation point 9 and the first end 10 of the arm 6. Furthermore, the arm 7 comprises at least a first part 23 including the actuation end 16, and at least a second part 25 including the actuation point 9 and the first end 11 of the arm 7.

The first part 22 of the arm 6 is foldable with respect to its second part 24, and the first part 23 of the arm 7 is foldable with respect to its second part 25.

The folding of the first parts 22, 23 with respect to the respective second parts 24, 25 is for example obtained by pivot connections between the respective first and second parts, visible in particular on the (but not referenced).

In another alternative embodiment (not shown in the figures), which can also apply to all the embodiments, the arm(s) 6, 7 are of adjustable length.

Specifically, here again, the arm 6 comprises at least a first part 22 including the actuation end 15, and at least a second part 24 including the actuation point 9 and the first end 10 of the arm 6. Furthermore, the arm 7 comprises at least a first part 23 including the actuation end 16, and at least a second part 25 including the actuation point 9 and the first end 11 of the arm 7.

The first part 22 of the arm 6 is then telescopically retractable at least partly in its second part 24, and the first part 23 of the arm 7 is then telescopically retractable at least partly in its second part 25.

As can be seen in the examples of Figures 8 to 14, the arm or arms 6, 7 are connected directly to the frame 5, by their respective first ends 10, 11, in the respective first pivot connections 12, 13, via elements 33, 31 mounted in the movable part of the frame 5 (for example in the movable part 50).

In the variant of Figures 8 to 10, the respective second ends 10, 11 of the arms 6, 6 are provided with respective openings 34, 32, allowing the respective axes of the first pivot links 12, 13 to translate over a given distance with respect to to the respective arms 6, 7, depending on the translation of the piston 4 and the rotation of the arms 6, 7 around the axis of the actuation point 9.

In the variant of Figures 11 to 13, a single opening 37 is formed in the arm 6, at the level of the actuation point 9, and an opening 35 is formed in the arm 7, at the level of this actuation point 9. These respective openings 37, 35 allow the axis of the actuation point 9 to translate relative to the arms 6, 7, depending on the translation of the piston 4 and the rotation of the arms 6, 7 around the axis from actuation point 9.

There shows yet another example, in which the arms 6 and 7 are connected to the piston 4 at the level of two distinct actuation points 9, by means of two respective connecting pieces 40, 41.

Specifically, the connecting piece 40 has a first end in which it is connected to the piston 4 at the corresponding actuation point 9, and a second end, opposite the first, in which it is connected to the arm 6 by a connection pivot 42. Similarly, the connecting piece 41 has a first end in which it is connected to the piston 4 at the corresponding actuation point 9, and a second end, opposite the first, in which it is connected to the arm 7 by a pivot link 43

This description is given by way of example and does not limit the invention.

In particular, the invention is not limited to a device in which the actuating means comprise a single arm, nor to a connection between the actuating means and the compression assembly strictly identical to those given in the examples. It extends in fact to a device whose actuating means comprise several arms, and in which the connection between the actuating means and the compression assembly reduces the force necessary for the translation of the piston, therefore application of cardiac massage.

Claims (10)

- Mechanical device for assisting cardiac massage on a subject, comprising
- a compression assembly (1) configured to be positioned on the subject's thorax and apply a massage to said thorax, and comprising a frame (5) and at least one piston (4) movable in guided translation in the frame (5) along a compression axis (Z),
- flexible positioning means (2) connected to the frame (5) and configured to make it possible to position and hold the compression assembly (1) against the subject's thorax,
- manual actuating means (3) configured to engage pressure by the piston (4) on the thorax of the subject and comprising at least one arm (6, 7),
the arm (6, 7) having an actuation end (15, 16) and a first end (10, 11) opposite the actuation end (15, 16) and connected to the frame (5) by a first pivot connection (12, 13), the piston (4) having a first end (8) intended to be positioned against the subject's thorax, and a second end (9) opposite its said first end (8) and connected to the arm (6, 7) at an actuation point (9) at a determined distance from said first pivot link (12, 13),
so as to allow, by an action on the actuating end (15, 16) of the arm (6, 7), the translation of the piston (4) along the compression axis (Z) between a position of rest in which, when the compression assembly (1) is positioned by the flexible positioning means (2) against the thorax of the subject, the piston (4) does not exert pressure on the thorax of the subject, and a position active in which, when the compression assembly (1) is positioned by the flexible positioning means (2) against the thorax of the subject, the piston (4) exerts pressure on the thorax of the subject. Device according to Claim 1, characterized in that the actuating means (2) comprise a second arm (6, 7) having an actuating end (15, 16) and a first end (10, 11) opposite the actuating end (15, 16) and connected to the frame (5) by a first pivot connection (12, 13), the second end (9) of the piston (4) being connected to the second arm (6, 7) in a second actuation point (9) at a determined distance from the first pivot link (12, 13) corresponding to the determined distance separating the actuation point (9) from the first pivot link (12, 13) from the other arm (6, 7),
so as to allow, by an action on each of the respective actuating ends (15, 16) of the two arms (6, 7), the translation of the piston (4) along the compression axis (Z) between a rest position in which, when the compression assembly (1) is positioned by the flexible positioning means (2) against the subject's thorax, the piston (4) does not exert pressure on the subject's thorax, and an active position in which, when the compression assembly (1) is positioned by the flexible positioning means (2) against the subject's thorax, the piston (4) exerts pressure on the subject's thorax. Device according to Claim 2, characterized in that the respective actuation points (9) of the two arms (6, 7) coincide. Device according to any one of Claims 1 to 3, characterized in that the frame (5) comprises a fixed part (17, 18, 51, 55) and a part (50) free to rotate around the compression axis. (Z), the piston (4) being rotatably mounted around the compression axis (Z) in the fixed part (17, 18, 51, 55), and the respective first end(s) (12, 13 ) of the arm or arms (6, 7) being connected to the movable part (50) by the respective first pivot link or links (10, 11), so as to allow rotation of the arm or arms (6, 7) and the piston (4) around the compression axis (Z). 5. Device according to any one of claims 1 to 4, characterized in that the second end (9) of the piston (4) is connected to the arm(s) (6, 7) at the actuation point (9) via a second pivot link (9). 6. Device according to any one of claims 1 to 4, characterized in that the arm or arms (6, 7) are configured, at the level of the actuation point (9), to be able to exert pressure on the second end (9) of the piston (4) along the compression axis (Z) when an action is exerted on the respective actuation end(s) (15, 16) of the arm(s) (6, 7). 7. Device according to any one of claims 1 to 6, characterized in that the actuating means (3) comprise, associated with each arm (6, 7), an intermediate arm (19a, 19b) of which a first end is connected to the frame (5) by the corresponding first pivot connection (12, 13), and of which a second end opposite its first end is connected to the first end (10, 11) of the corresponding arm (6, 7) by a intermediate pivot link (20, 21). 8. Device according to any one of claims 1 to 7, characterized in that the positioning means (2) comprise at least one strap (28, 29), preferably two straps (28, 29) substantially parallel, each of straps (28, 29) having two opposite ends connected to the frame (5), said straps (28, 29) being configured to surround the subject's thorax and hold the frame (5) against the subject's thorax regardless of the perimeter of said thorax. 9. Device according to any one of claims 1 to 8, characterized in that the arm or arms (6, 7) comprise at least a first part (22, 23) including the actuating end (16, 17) of the corresponding arm (6, 7), and at least a second part (24, 25) including the actuation point (9) and the first end (10, 11) of the corresponding arm (6, 7), said first part (22, 23) being collapsible with respect to said second part (24, 25). 10. Device according to any one of claims 1 to 9, characterized in that the arm or arms (6, 7) comprise at least a first part (22, 23) including the actuating end (16, 17) of the corresponding arm (6, 7), and at least a second part (24, 25) including the actuation point (9) and the first end (10, 11) of the corresponding arm (6, 7), said first part (22, 23) being telescopically retractable at least partly into said second part (24, 25).