Thorax and manikin for cardiopulmonary resuscitation with delivery of gaseous CO.SUB.2

Abstract

An artificial thorax (1) with at least one deformable air reservoir (2) having an internal volume (3) containing air and a first orifice (4) in fluidic communication with the internal volume (3), the deformable air reservoir (2) deforming, and at least some of the air leaving the internal volume (3) via the first orifice (4), when a user exerts a manual compression action, directly or indirectly, on said deformable air reservoir (2). The artificial thorax (1) has a CO.sub.2 source (10) containing gaseous CO.sub.2, such as a gas cylinder, connected fluidically (11) to the internal volume (3) of the deformable air reservoir (2) in such a way as to supply said internal volume (3) with gaseous CO.sub.2.

Claims

1. An artificial thorax comprising at least one deformable air reservoir comprising an internal volume containing air and comprising a first orifice in fluidic communication with the internal volume, said deformable air reservoir capable of deforming, and having at least some of the air leaving the internal volume via the first orifice, when a compression action is exerted, directly or indirectly, on said deformable air reservoir, wherein the artificial thorax additionally comprises a CO.sub.2 source containing CO.sub.2, connected fluidically to the internal volume of the deformable air reservoir in such a way as to be adapted to supply said internal volume with gaseous CO.sub.2.

2. The artificial thorax according to claim 1, further comprising at least one actuator which can be actuated manually by a user and which interacts with said at least one deformable air reservoir in such a way that, when the user exerts a manual compression action on said at least one movable actuator, said at least one movable actuator acts, directly or indirectly, on said deformable air reservoir in order to deform the latter.

3. The artificial thorax according to claim 2, further comprising at least one elastic compression device and/or at least one elastic return device interacting with said at least one actuator and/or with said deformable air reservoir.

4. The artificial thorax according to claim 3, wherein the at least one elastic compression device and/or the at least one elastic return device are arranged inside the internal volume of the deformable air reservoir.

5. The artificial thorax according to claim 1, wherein the CO.sub.2 source contains CO.sub.2 at a content greater than 5% by volume.

6. The artificial thorax according to claim 1, wherein the CO.sub.2 source is a pressurized gas container, in particular a gas cylinder.

7. The artificial thorax according to claim 1, wherein the CO.sub.2 source is arranged in such a way as to supply the internal volume of the deformable air reservoir with gaseous CO.sub.2 so as to obtain an air/CO.sub.2 mixture in said internal volume.

8. A manikin for training, demonstration or simulation, comprising an artificial thorax according to claim 1, said manikin having a human form with a torso and a head.

9. The manikin according to claim 1, further comprising a mouth with a gas orifice connected fluidically to the first orifice of the deformable air reservoir.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a further understanding of the nature and objects for the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements are given the same or analogous reference numbers and wherein:

(2) FIG. 1 is a schematic representation of an artificial thorax according to the invention, and

(3) FIG. 2 is a schematic representation of a manikin comprising an artificial thorax according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(4) Carbon dioxide (CO.sub.2) holds an essential place in cardiopulmonary resuscitation (CPR). Thus, according to the international recommendations of the European Resuscitation Council (ERC), the monitoring of CO.sub.2 is recommended during CPR for several reasons: to ensure the correct positioning of the endotracheal probe during intubation, to assess the efficacy of the chest compressions, to calculate the breathing rate, to detect the recovery of spontaneous cardiac activity (RSCA), and to help the prognosis of the patient.

(5) During CPR performed on a person in cardiopulmonary arrest, with use of cardiac massage, the alveolar CO.sub.2, which depends not only on the ratios between ventilation and pulmonary perfusion but also on the quantity of CO.sub.2 generated by the cell metabolism, is a very useful parameter for allowing the first responder, for example a doctor, to judge the efficacy of the CPR.

(6) Good ventilation is crucial for eliminating the CO.sub.2. Indeed, the more effective the CPR, the greater the cardiac output generated by the chest compressions, and therefore the larger the quantity of CO.sub.2 returned to the lungs. In mechanical ventilation apparatuses, the CO.sub.2 is monitored by measuring the parameter EtCO.sub.2 (End tidal CO.sub.2) which is an indirect reflection of the alveolar CO.sub.2.

(7) The venous return is also a very important element during CPR. It is due to the negative intrathoracic pressure (ITP) resulting from the forces of recoil of the thorax during relaxation. The amplitude of this negative pressure is influenced principally by the return of the pulmonary volume to the residual functional capacity (RFC), The RFC corresponds to the residual volume of air in the lungs after a spontaneous and unforced exhalation. In reality, in the very specific case of cardiac arrest, the RFC is quite simply the volume of air present in the lungs when the patient collapses. The pulmonary volume thus appears to be an essential element in the case of CPR.

(8) A manikin equipped with an artificial thorax permits as precise as possible a reflection of the important physiological phenomena to be taken into account during CPR, and taking place in the thorax and the respiratory system, and thus makes it possible to realistically simulate a patient in cardiac arrest, especially during a cardiopulmonary resuscitation (CPR) training session and/or demonstration with use of chest compressions.

(9) In the context of the present invention, a manikin equipped with an artificial thorax is proposed which is improved in relation to existing ones since it makes it possible to take account of the pulmonary gas exchanges, in particular to simulate a quantity of CO.sub.2 expelled by the lungs of the manikin on account of the chest compressions, and thereby to assist the first responders carrying out the cardiac massage by teaching them to take account of this CO.sub.2, in particular to determine a recovery of spontaneous cardiac activity (RSCA).

(10) FIG. 1 shows a schematic representation of an artificial thorax 1 for a resuscitation manikin according to the invention, making it possible to simulate and preferably measure the gas exchanges, in particular the flushing of CO.sub.2 upon each chest compression, for example during a CPR training session and/or demonstration with use of chest compressions, that is to say a cardiopulmonary massage.

(11) The artificial thorax 1 comprises a deformable air reservoir 2, for example made of elastomer material or similar, having a longitudinal axis (AA) and defining an internal volume 3 containing air. This deformable air reservoir 2 can have a bellows shape, that is to say a peripheral wall 78 with an “accordion” shape or similar. The internal volume 3 of the deformable air reservoir 2 represents the pulmonary volume of a patient, also called the residual functional capacity (RFC), and is of the order of 2.5 to 3 litres (about 30 ml/kg).

(12) Moreover, the deformable air reservoir 2 comprises a first orifice 4 in fluidic communication with the internal volume 3 and is designed to deform and to expel at least some of the gas contained in it through the first orifice 4 when a user, for example a first responder learning to perform cardiac massage, exerts a manual compression action, directly or indirectly, on the deformable air reservoir 2, typically an axial compression along the axis (AA), that is to say from the top downward in FIG. 1.

(13) Preferably, it moreover comprises a movable actuator 5 which can be actuated manually by the user and which interacts with the deformable air reservoir 2 in such a way that, when the user exerts a manual compression action on this movable actuator 5, the latter acts directly or indirectly on the deformable air reservoir 2 in order to deform the latter and expel gas from it via the first orifice 4.

(14) The actuator 5 can be, for example, a rigid plate or similar. This actuator 5 in fact simulates the thoracic cage of the patient.

(15) In order to permit the downward and upward movements of the actuator 5 and the axial compressions and relaxations (AA) of the deformable air reservoir 2, one or more elastic compression devices 6 and one or more elastic return devices 7 are also provided which interact with the actuator 5 and/or with the deformable air reservoir 2, of which the resistance and repulsion forces are chosen to reproduce the mechanical properties of the respiratory system of an individual in cardiac arrest.

(16) Preferably, the elastic compression device 6 comprises one or more first springs, called compression springs, and the elastic return device 7 comprises one or more second springs, called extension springs. Advantageously, they are arranged inside the internal volume 3 of the deformable air reservoir 2, as can be seen in FIG. 1, that is to say inside the bellows. Such an internal thorax architecture is conventional and known from WO-A-2016/030393, to which reference may be made for further details.

(17) Thus, the one or more compression springs make it possible to create a resistance during massage, that is to say upon each chest compression that the first responder applies to the actuator 5, i.e. along the axis (AA) in the downward direction, while the one or more extension springs create a resistance to the air insufflation, that is to say in the relaxation period (i.e. the period free of chest compression) during which mechanical ventilation may be implemented, for example with the aid of an assisted ventilation apparatus, also called a medical ventilator, or a manual ventilation balloon, also called a bag valve mask, making it possible to insufflate air to the patient.

(18) According to the invention, in order to be able to simulate and possibly measure the gas exchanges, in particular the flushing of CO.sub.2 upon each chest compression, during the use of such an artificial thorax, in particular when it is integrated in a resuscitation manikin as illustrated in FIG. 2, for example during a CPR training session and/or demonstration, with a view to improving the training of first responders by allowing them to perform effective cardiac massage also taking account of the pulmonary gas exchanges of the patient, a CO.sub.2 source 10 containing gaseous CO.sub.2 is provided, which is connected fluidically to the internal volume 3 of the deformable air reservoir 2 in such a way as to supply this internal volume 3 with gaseous CO.sub.2 and to obtain an air/CO.sub.2 mixture which can then be monitored.

(19) More precisely, the artificial thorax 1 for a resuscitation manikin 20 according to the invention, supplied via such a CO.sub.2 source 10, permits modelling of the thoracic cage and of the pulmonary compartment of a patient in cardiac arrest in order to simulate the gas dynamics induced during the chest compression movements performed by the first responder, in particular the expulsion of CO.sub.2.

(20) Indeed, the CO.sub.2 delivered directly to the patient's lungs by the chest compressions during the cardiac massage makes it possible to obtain a representation of the CO.sub.2 production over the course of the CPR, and it is therefore imperative to be able to simulate it during training or the like on a training manikin 20.

(21) According to the invention, by having a realistic pulmonary volume, i.e. 2.5 to 3 l of internal volume 3, associated with a suitable variable supply of CO.sub.2 from the CO.sub.2 source 10 in the respiratory system of the artificial thorax 1 of the manikin 20, it is possible to reproduce faithfully the gas exchanges that occur during a cardiac arrest, that is to say the insufflation of air containing oxygen (O.sub.2) during ventilation with insufflation of air, and the exhalation of gas rich in CO.sub.2, upon each chest compression caused by the cardiac massage.

(22) The CO.sub.2 source 10 is advantageously a small cylinder of pressurized gas, that is to say a cylinder having an internal volume of 10 l or less (water equivalent), for example 2 l to 5 l, and containing pure CO.sub.2 (100%) or a mixture of CO.sub.2 with a carrier gas, for example an inert gas, such as nitrogen, at a pressure of less than or equal to 200 bar abs.

(23) As is illustrated in FIG. 1, the CO.sub.2 cylinder 10, for example made of aluminium alloy, is connected fluidically to the internal volume 3 of the deformable reservoir 2 by a flexible hose 11 which communicates with the internal volume 3 via a second orifice 9 permitting introduction of CO.sub.2 into the internal volume 3.

(24) The CO.sub.2 cylinder 10 is equipped with a gas supply valve, for example a valve with a built-in gas regulator or similar, making it possible to reduce the gas pressure to a use pressure of the order of a few bar abs., for example of the order of 1 to 4 bar abs.

(25) Moreover, CO.sub.2 release control means are provided for controlling the addition of CO.sub.2 in the deformable air reservoir 2 and thus the formation of the air/CO.sub.2 mixture in the internal volume 3 of the deformable air reservoir 2.

(26) The CO.sub.2 release control means comprise valve means 30, for example a controlled solenoid valve, or a manually regulated mechanical device.

(27) The valve means 30 are arranged between the CO.sub.2 source 10 and the deformable air reservoir 2, typically on the pathway of the gas between the CO.sub.2 source 10 and the deformable air reservoir 2, for example on the gas supply line 11, such as a gas conduit, connecting the CO.sub.2 source 10 to the deformable air reservoir 2, as is indicated schematically in FIG. 1.

(28) Advantageously, one or more sensors 32 are also provided, which are configured to evaluate the quality of the chest compressions, that is to say parameters representative of the chest compressions, such as the chest compression rate, the amplitude of the chest compressions, return to the initial position upon relaxation during the chest compression cycles, position of the hands on the chest, etc.

(29) Preferably, the valve means 30 are operated by operating means 31, preferably an electronic board comprising or more microprocessors, preferably a microcontroller, in such a way as to adjust, set or regulate the quantity of CO.sub.2 introduced into the deformable air reservoir 2.

(30) According to one embodiment, the operating means 31 are configured to act on the valve means 30 in response to at least one signal delivered by the one or more sensors 32 serving to evaluate the quality of the chest compressions (i.e. rate, amplitude, etc.), in such a way as to deliver automatically a CO.sub.2 quantity or flow rate that is a function of said quality of the chest compressions.

(31) According to another embodiment, the operating means 30 can also be configured to act on the valve means 31 in order to adjust or set the quantity or flow rate of CO.sub.2 delivered to the deformable air reservoir 2 in accordance with a CO.sub.2 quantity that is (pre)set or selected by a user.

(32) Generally, the operating means 31 are configured to act on the valve means 30 proportionally or in an all-or-nothing basis.

(33) Moreover, it comprises CO.sub.2 monitoring means including means 33 for measuring the CO.sub.2 content, such as a CO.sub.2 sensor or capnometer, and signal processing means 34.

(34) The means 33 for measuring the CO.sub.2 content, that is to say the capnometer, are designed or configured to carry out CO.sub.2 concentration measurements in the gas arriving from the deformable air reservoir 2, that is to say the air/CO.sub.2 mixture, and to deliver CO.sub.2 content measurement signals to the signal processing means 34.

(35) In the embodiment in FIG. 2, the CO.sub.2 sensor 33 is arranged in a “mainstream” configuration as close as possible to the mouth 25 of the manikin 20. However, it could also be arranged as close as possible to the outlet orifice 4 of the deformable air reservoir 2, or else between this outlet orifice 4 and the mouth 25 of the manikin 20.

(36) The CO.sub.2 sensor 33 is connected (via 35) to the signal processing means 34, typically an electronic board with microprocessor, preferably a microcontroller, using one or more algorithms, in such a way as to transmit thereto the CO.sub.2 content measurement signals coming from said sensor 33.

(37) For their part, the signal processing means 34 are configured to process the CO.sub.2 content measurement signals that are delivered. They interact with display or viewing means 36, for example a screen of a computer or similar, in such a way as to transmit thereto and display there one or more information items, values, data, graphical representations, especially CO.sub.2 values or curves, or similar. In particular, the display means 36 are configured to display at least a CO.sub.2 concentration or content in numerical or analog form, in particular in the form of graphical representations, such as curves, graphs, etc.

(38) The link 37 between the signal processing means 34 and the display means 36, permitting in particular the transmission of data or similar, can be a wired or wireless link, for example Wifi or Bluetooth.

(39) It will be noted that the electronic boards 31, 34 can be in the form of one or several electronic boards.

(40) FIG. 2 shows a schematic representation of a manikin 20 comprising an artificial thorax 1 according to the invention and the other elements mentioned above.

(41) In this embodiment, the manikin 20 comprises an outer envelope having the general form of a human body, here with a torso 24 and a head 23. The envelope 26 can be rigid or semi-rigid, for example made of polymer, and can be covered with a flexible artificial fabric 27 representing the skin. Preferably, the head comprises a face with a nose and eyes and with a mouth 25 provided with a gas orifice 22 and connected fluidically to the internal volume 3 of the deformable reservoir 2 via a gas passage 21, such as a tube, a gas conduit or similar, and the first orifice 4 of the reservoir 2.

(42) The gas passage 21 permits the gas exchanges from the reservoir 2 to the mouth 25 and the gas outlet orifice 22, during the chest compressions, and the delivery of the gas, in the opposite direction, that is to say towards the deformable reservoir 2, during the insufflation of gas in the periods without chest compression, when the manikin 20 is connected fluidically to an artificial ventilation device, such as a medical ventilator or a bag mask valve, that is to say a self-filling balloon with one-way valve (not shown).

(43) The manikin 20 with artificial thorax 1 according to the invention can be used for CPR training, for CPR demonstrations, for practice or for any other purposes, in particular for testing a CPR-specific device with a view to simulating the airways of a person. According to other embodiments, it can also comprise arms and/or legs.

(44) By virtue of a controlled delivery of CO.sub.2 and of an internal volume 3 representing the residual functional capacity (RFC) of a patient, a manikin 20 of this kind constitutes a physiological model representative of a patient in cardiorespiratory arrest (CRA).

(45) According to the invention, the addition of CO.sub.2 to the air contained in the internal volume 3 of the reservoir 2 makes it possible to simulate good cardiac massage and poor cardiac massage, hence to reflect and simulate the mechanisms inherent to the physiology of cardiac arrest. Indeed, in vivo monitoring of the CO.sub.2 expelled during chest compressions is a very good indicator of the quality of the chest compressions and of the patient's circulation.

(46) The addition of CO.sub.2 is effected by virtue of the gaseous CO.sub.2 arriving from a CO.sub.2 source 10, such as a small cylinder or CO.sub.2 cartridge, as explained above, which can either be integrated in the envelope of the manikin 20, as illustrated in FIG. 2, or placed outside the manikin 20.

(47) Such an artificial thorax 1 and/or manikin 20 according to the invention can be used during a cardiopulmonary resuscitation (CPR) training session, demonstration or simulation with use of successive chest compressions applied to said artificial thorax 1 or manikin 20.

(48) It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above.