A system for generating blood circulation

Abstract

The present invention relates to a system (1) for generating blood circulation in at least a part of an organ of a vertebrate, comprising a first artificial cavity (11) and a second artificial cavity (12), each of which comprises a flexible membrane (21), (22) capable of jumping under the action of gas, each of which separates a blood circulation chamber (31), (32) and a chamber (41), (42) containing the gas in a sealed manner, the system comprising: a first low-pressure gas buffer tank (51); a second high-pressure gas buffer tube (52); a gas distribution mechanism (6); and a pneumatic pump (7).

Description

Technical Field

[0001] The present invention relates to the design and manufacture of medical devices and equipment.

[0002] More specifically, the present invention relates to devices for artificially creating the blood flow normally provided by the heart of a vertebrate. The present invention particularly, but not exclusively, relates to medical devices implantable in the pericardial cavity of a vertebrate. Background Art

[0003] In the field of inventions, we know devices implementing the pneumatic pump concept and devices implementing the hydraulic pump concept.

[0004] Historically, the first artificial hearts have used the concept of a pneumatic pump. These artificial hearts had to be implanted inside the patient's chest, and an external device capable of generating air pressure was connected to the artificial heart to activate it through air flow.

[0005] In this technology, the artificial heart includes an artificial cavity, inside which a flexible membrane is located. Then, inside the cavity, the membrane separates the blood circulation chamber and the gas chamber in a sealed manner. Via a connecting hose that connects an external device to the artificial heart, pulse compressed air is supplied to the gas chamber in each artificial cavity to generate blood flow using the membrane pump principle.

[0006] This type of solution is robust and reliable.

[0007] However, this concept requires particularly heavy external equipment and involves introducing air ducts into the body to the artificial heart. Therefore, patients equipped with such an artificial heart do not enjoy significant autonomy.

[0008] In the second type of technology, artificial hearts with hydraulic motor systems have been proposed.

[0009] This hydraulic core has an anthropomorphic design and allows for significant autonomy compared to previously described artificial cores that use pneumatic technology.

[0010] In fact, this type of hydraulic artificial heart based on the diaphragm pump concept incorporates a motor system that generates the pulsating pressure directly inside the artificial heart.

[0011] This artificial heart uses a temporary battery implanted in the vertebrate body and requires only an external battery recharging system that does not contain any invasive connectors designed to enter the body to electrically power the heart.

[0012] However, this system is not as robust and reliable as hearts that use pneumatic technology.

[0013] Still known is the solution described in patent document published under number US 4516567, which discloses a fully pneumatic artificial heart operated by a single pump. The pump injects or sucks air at the membrane to generate blood flow.

[0014] A disadvantage of this heart is that it requires a high performance pump that can withstand significant pressures during each sub-period of the cardiac surgery cycle, since the pump directly infuses / suctions large volumes of fluid moving onto or away from the membrane. Summary of the invention

[0015] One of the objects of the present invention is to resolve these disadvantages of the prior art.

[0016] One of the objectives of the present invention is to propose a system for producing blood circulation that is more robust and reliable than the prior art solutions implementing the concept of a hydraulic heart.

[0017] The present invention also aims to provide such an energy-saving blood circulation generating system.

[0018] The invention also aims to provide such a system which is less bulky than solutions according to the prior art implementing the pneumatic pump concept.

[0019] More specifically, the present invention aims to provide such a solution which is sufficiently small to be easily implemented inside a total artificial heart intended to be implanted in the chest cavity of a vertebrate.

[0020] These objectives, as well as others that will follow, are achieved by the present invention, the object of which is a system for producing blood circulation in at least a portion of an organ of a vertebrate, comprising a first artificial cavity and a second artificial cavity, said cavities each comprising a flexible membrane capable of beating under the action of a gas, each of said membranes sealingly separating a blood circulation chamber from a chamber containing said gas, wherein it comprises:

[0021] a first gas buffer container, which is intended to substantially reach a first pressure (the so-called low pressure), and a second gas buffer container, which is intended to substantially reach a second pressure (the so-called high pressure) higher than said first pressure;

[0022] a gas distribution mechanism connected to the chambers containing the gas of the first and second artificial chambers and the first and second buffer containers, the gas distribution mechanism being arranged to alternately inject gas into the chambers containing the gas and exhaust gas from the chambers containing the gas to provide a predetermined value of blood flow rate in the blood flow chambers of the first chamber and the second chamber;

[0023] A pneumatic pump supplied with electrical energy and installed between the first buffer container and the second buffer container and intended to draw gas from the first tank in order to inject it into the second tank.

[0024] Thanks to the generating system according to the invention, blood circulation can be artificially generated without the system being as bulky as pneumatic systems according to the prior art using external equipment. The generating system according to the invention can also have a much lower energy consumption than pneumatic systems according to the prior art.

[0025] In fact, according to the principles of the present invention, the only function of the pneumatic pump is to maintain the pressure difference between the first gas buffer container and the second gas buffer container.

[0026] Unlike the prior art, this pump is not used to inject and pump the motive fluid (here the gas) directly at the level of the chamber containing said gas in each artificial cavity.

[0027] According to the invention, the first gas buffer container and the second gas buffer container are used to supply or extract motive fluid from the chamber containing the gas so as to make the flexible membrane beat and form blood circulation.

[0028] Thus, using a single pump to generate the pressure difference between the first gas buffer container and the second gas buffer container allows a system with low overall energy losses, in particular lower than the energy losses of pneumatic systems according to the prior art.

[0029] In other words, the first gas buffer container and the second gas buffer container serve as energy storage reserves. The distribution of this energy is permitted and controlled by a gas distribution mechanism connecting the chamber containing said gas to the first gas buffer container and the second gas buffer container.

[0030] Preferably, the first and second artificial chambers, the first and second gas buffer containers, the gas distribution mechanism and the pneumatic pump form an integral unit, and the system for generating blood circulation also includes a battery for supplying electrical energy to the pump and the gas distribution mechanism.

[0031] In this way, the production system according to the invention can be at least temporarily self-sufficient and have an advantageous autonomy in supplying blood to organs connected to the system.

[0032] A preferred feature of the pump is that it is a vane pump.

[0033] A rotary vane pump for generating the high pressure in the second gas buffer container and the low pressure in the first gas buffer container is particularly suitable for achieving a low overall energy consumption of the generation system according to the invention.

[0034] This vane pump compensates for the internal leakage and flow rate consumed by the heart pump drive.

[0035] As a further advantageous feature, the gas distribution mechanism comprises at least one piezoelectric switch and / or at least one shape memory switch and / or at least one electromagnetic switch.

[0036] Such a gas distribution mechanism forms a particularly suitable solution for the miniaturization of these distribution mechanisms.

[0037] Preferably, the gas is air.

[0038] This gas allows the system to operate properly and simply without the need for a special gas supply which is expensive and may be difficult to obtain.

[0039] It should be noted that the values ​​of the first and second pressures are adjusted according to the patient.

[0040] The pressure in the buffer container is regulated according to the heartbeat to ensure blood flow that corresponds to the patient's needs.

[0041] This control is done electronically via sensors integrated into the system.

[0042] Advantageously, the gas distribution mechanism comprises a 4-way 2-position valve.

[0043] These gas distribution means ensure a gas exchange between a first gas buffer container and a second gas buffer container, wherein the chambers contain said gas of the artificial cavity.

[0044] In this case, the valve is preferably a pilot-operated flap valve and / or a pilot-operated slide valve.

[0045] A first preferred solution is that the system for generating blood circulation forms a total heart prosthesis to be implanted in the patient's pericardial cavity and capable of replacing the patient's left ventricle and right ventricle after removal of the patient's left ventricle and right ventricle, wherein the first and second chambers form a biventricular module, the blood circulation chamber of the first artificial chamber is intended to be connected to the patient's left atrium and aorta, and the blood circulation chamber of the second artificial chamber is intended to be connected to the patient's right atrium and pulmonary artery.

[0046] Such a total heart prosthesis can then combine the robustness and reliability of a pneumatic implant with the small size of a total prosthesis using hydraulic motor fluid according to earlier techniques. Furthermore, a total heart prosthesis according to the total generation system of the present invention can be completely autonomous and requires only a small amount of electricity to operate the gas distribution mechanism and the pneumatic pump.

[0047] According to a second preferred solution, the system for generating a blood circulation forms a circuit for extracorporeal perfusion of the organ, making it possible to keep the organ alive for transplantation.

[0048] In fact, the generating system according to the invention makes it possible to ensure extracorporeal blood circulation thanks to a particularly compact device which is less bulky than those known from the prior art and requires only a very low energy input (approximately 15 W to 20 W).

[0049] Preferably, the system for generating blood circulation, eg as described above, comprises one and only one pneumatic pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Other features and advantages of the present invention will become more apparent upon reading the following description and the accompanying drawings which form a preferred mode of the invention, given by way of illustrative and non-limiting examples, in which:

[0051] Figure 1 is a schematic diagram of a system for producing blood circulation according to the invention, wherein the chamber containing the gas is connected to a second (high pressure) gas buffer container, and the blood circulation chamber then has a small volume;

[0052] Figure 2 is a schematic diagram of the same system for generating blood circulation, where the chamber containing the gas is connected to a first (low pressure) gas buffer container and then the blood circulation chamber has a large volume. DETAILED DESCRIPTION

[0053] refer to Figure 1 and Figure 2 The system 1 for generating blood circulation allows artificial generation of blood flow in at least a portion of a vertebrate organ. Specifically, the system 1 is used to generate blood flow in two circuits of blood flow, comprising:

[0054] The first circulation loop C1 of blood flow;

[0055] The second circulation loop C2 of blood flow.

[0056] As will be described in detail later, as a first preferred solution, the system 1 for generating blood circulation can form a total heart prosthesis. In this case, for example, the first circulation circuit C1 of the blood flow corresponds to the anatomical circulation circuit supplying oxygenated blood to the body of a vertebrate, and the second circulation circuit C2 of the blood flow corresponds to another anatomical circulation circuit for oxygenating the blood (this other circulation circuit particularly integrates the lungs of a vertebrate).

[0057] According to a second preferred solution, the system 1 for producing blood circulation can form an extracorporeal blood circulation circuit of an organ. Then, in this case, at least one of the first circulation circuit C1 of blood flow or the second circulation circuit C2 of blood flow is connected to the organ to supply blood thereto.

[0058] like Figure 1 and Figure 2 As shown in FIG. 1 , a system 1 for generating blood circulation comprises:

[0059] A first artificial cavity 11;

[0060] A second artificial cavity 12;

[0061] A first gas buffer tank 51;

[0062] A second gas buffer tank 52;

[0063] A gas distribution mechanism 6, which connects the first artificial cavity 11 and the second artificial cavity 12 to the first gas buffer tank 51 and the second gas buffer tank 52;

[0064] A pneumatic pump 7 is connected to the first gas buffer tank 51 and the second gas buffer tank 52 .

[0065] The first artificial cavity 11 and the second artificial cavity 12 each include a flexible membrane 21, 22 that can be moved by the action of gas. In fact, the system 1 for generating blood circulation is a pneumatic system and uses gas as a driving fluid to allow blood circulation to be generated. This gas is preferably air.

[0066] These flexible membranes 21, 22 are elastic and divide the first artificial cavity 11 and the second artificial cavity 12 into two chambers, respectively.

[0067] More specifically:

[0068] The flexible membrane 21 of the first artificial cavity 11 separates the blood circulation chamber 31 and the chamber 41 containing the gas in the first cavity 11 in a sealed manner;

[0069] The flexible membrane 22 of the second artificial cavity 12 separates the blood circulation chamber 32 and the chamber 42 containing the gas in the second cavity 12 in a sealed manner;

[0070] The first artificial cavity 11 and the second artificial cavity 12 further include:

[0071] Blood injection valves 312, 321 in blood circulation chambers 31, 32;

[0072] Blood is ejected from blood circulation chambers 31 and 32 through valves 311 and 322 .

[0073] These injection valves 312, 321 and ejection valves 311, 322 ensure that the direction of blood flow in the system is guaranteed. The specific arrangement of each valve 311, 312, 321, 322 enables the operating pressure of the artificial cavity to be adjusted.

[0074] As mentioned above, the flexible membranes 21, 22 are able to bounce under the action of gas.

[0075] The flexible membranes 21 , 22 each change the volume of the blood circulation chambers 31 , 32 by pulsating.

[0076] When the volume of the blood circulation chambers 31, 32 increases, the pressure in the blood circulation chambers 31, 32 decreases and causes the ejection valves 311, 322 to close and the injection valves 312, 321 to open to allow the blood circulation chambers 31, 32 to be filled with blood.

[0077] Conversely, when the volume of the blood circulation chambers 31, 32 decreases, the pressure inside the blood circulation chambers 31, 32 increases and causes the injection valves 312, 321 to close and the ejection valves 311, 322 to open to allow blood to be discharged from the blood circulation chambers.

[0078] The gas exchange (injection and extraction) at the level of the chambers 41 , 42 containing said gases is ensured by:

[0079] Gas distribution mechanism 6;

[0080] A first gas buffer container 51;

[0081] A second gas buffer container 52;

[0082] Pneumatic pump 7.

[0083] The first gas buffer tank 51 is intended to be raised to a first pressure, the so-called low pressure.

[0084] As for the second gas buffer tank 52 , it is intended to be raised to a second pressure (referred to as high pressure) which is higher than the first pressure.

[0085] As an example, the first pressure may be increased to 1.1 bar and the second pressure may be increased to 1.15 bar.

[0086] Preferably, the operation of the pneumatic pump is dependent on a "heart rate" defined by the gas distribution mechanism in order to maintain the pressure within the above limits.

[0087] In this case, the control of the system 1 is performed electronically by means of sensors integrated in the system.

[0088] like Figure 1 and Figure 2 It is shown that the pneumatic pump 7 is installed between the first buffer tank 51 and the second buffer tank 52.

[0089] The pneumatic pump 7 draws gas from the first buffer tank 51 and injects it into the second buffer tank 52. In this way, the pneumatic pump 7 allows the first buffer tank 51 to be maintained at approximately its low pressure, and the second buffer tank 52 to be maintained at approximately its high pressure.

[0090] For operation, the pneumatic pump 7 is supplied with electrical energy.

[0091] The pump is advantageously a vane pump 70. A vane pump is a positive displacement pump consisting of a stator (fixed) and a rotor (movable) rotating tangentially to the stator. The vanes are fixed to the rotor and can slide in the rotor housing perpendicular to the axis of rotation of the rotor to contact the stator wall by centrifugal force. In addition to the centrifugal force, the rotor can include a mechanism for returning the vanes to a position of contact with the stator wall.

[0092] Preferably, as shown in the figures, the pneumatic pump 7 is exclusive.

[0093] As described above, the gas distribution mechanism 6 is coupled to the first artificial cavity 11 , the second artificial cavity 12 and the buffer tank. Specifically, the gas distribution mechanism 6 is connected to the gas chambers 41 , 42 , the first buffer tank 41 and the second buffer tank 42 .

[0094] The gas distribution mechanism 6 is arranged to alternately inject gas into and extract gas from the chambers 41, 42 containing said gas in order to ensure a predetermined value of the blood flow rate in the blood circulation chamber of the artificial cavity.

[0095] In other words, the gas distribution mechanism 6 (and the buffer tank) allows the pressure of the chambers 41 , 42 containing the gas to be modified so as to cause an expansion or reduction in the volume of these chambers due to the elastic deformation of the flexible membranes 21 , 22 .

[0096] The repeated changes in the volume of the chamber containing the gas mechanically lead to repeated changes in the volume of the blood circulation chambers 31 , 32 .

[0097] This change in the volume of the blood circulation chambers 31 , 32 also leads to a change in the blood pressure in these chambers.

[0098] Therefore, by alternately injecting and extracting gas, the gas distribution mechanism 6 forms blood flow by pumping blood into the blood circulation chambers 31, 32 and discharging blood from these blood circulation chambers 31, 32 through the above-mentioned injection valves 312, 321 and ejection valves 311, 322.

[0099] Preferably, the gas distribution mechanism 6 comprises at least one piezoelectric switch and / or at least one shape memory switch and / or at least one electromagnetic switch.

[0100] like Figure 1 and Figure 2 , the gas distribution mechanism 6 comprises a 4-way 2-position valve 60. The valve 60 may be a pilot-operated slide valve 60 or a flap valve.

[0101] In fact, reference Figure 1, the distributor 60 adopts a first position, in which the second buffer tank 52 (high pressure) is connected to the chamber 41 containing the gas of the first artificial cavity 11 and the chamber 42 containing the gas of the second artificial cavity 12. In this case, the high-pressure gas in the second buffer tank 52 is injected into the chambers 41, 42 containing the gas.

[0102] After the valve 60 passes through its second position, as Figure 2 It is shown in FIG. 2 that the second buffer tank 52 is no longer in communication with the chambers 41 , 42 containing the gas, and the chambers are then in communication with the first buffer tank 51 (low pressure) and the gas.

[0103] According to the present embodiment, the chambers 41, 42 containing the gas are simultaneously communicated with the first buffer tank 51 or the second buffer tank 52. Therefore, the blood circulation chambers 31, 32 are synchronously filled and drained with blood.

[0104] In other possible embodiments, the valves may be configured to asynchronously fill and drain the blood from the blood circulation chambers 31 , 32 and / or to perform these fillings or drains at different rates between each artificial cavity.

[0105] Preferably, the first artificial cavity 11 and the second artificial cavity 12 , the first gas buffer tank 51 and the second gas buffer tank 52 , the gas distribution mechanism 6 and the pneumatic pump 7 form a one-piece unit.

[0106] The system 1 for producing blood circulation also comprises a battery for supplying electric energy to the pneumatic pump 7 and the gas distribution mechanism 6 for installation in the abdominal cavity. This battery is recharged by transcutaneous induction.

[0107] As described above, the blood circulation generation system 1 can form a whole heart prosthesis. In this case, the system 1 is intended to be implanted in the pericardial cavity of the patient. Then, the system 1 can be used to replace the patient's ventricles (left and right). Therefore, the first artificial chamber 11 and the second artificial chamber 12 form a biventricular module, wherein the blood flow chamber 31 of the first artificial chamber 11 is connected to the patient's left atrium and aorta, and the blood flow chamber 32 of the second artificial chamber 12 is connected to the patient's right atrium and pulmonary artery.

[0108] An example development of an operating cycle of a total heart prosthesis is as follows.

[0109] The contraction of the heart ejects blood from the blood circulation chamber (artificial ventricle) into the blood circulation circuits C1 and C2.

[0110] During cardiac diastole, blood contained in the blood circulation circuits C1 and C2 (blood from the left atrium and the right atrium) is injected into the blood circulation chambers 31 and 32 (blood is sucked into the artificial ventricle).

[0111] The change from diastole to systole (and vice versa) causes a change in the pressure development (increase and decrease in pressure) in the blood flow chambers 31 , 32 and causes a change in the state of the injection valves 312 , 321 and the ejection valves 311 , 322 .

[0112] During the transition from diastole to systole, the ejection valves 311, 322 (aortic valve and pulmonary valve) change from a closed state to an open state, and the injection valves 312, 321 (atrioventricular valve) change from an open state to a closed state.

[0113] When the heart changes from systole to diastole, the ejection valves 311, 322 (aortic valve and pulmonary valve) change from an open state to a closed state, and the injection valves 312, 321 (atrioventricular valve) change from a closed state to an open state.

[0114] In the initial state of heart contraction, the chambers 41, 42 containing the gas each have a volume of approximately 5 mL and a pressure of approximately 0.107 Bar, the blood circulation chambers 31, 32 (artificial ventricles) are filled with blood, the valve 60 has been switched, and the chambers 41, 42 containing the gas have just been connected to the second buffer container 52 (high pressure).

[0115] The pressure in the chamber 41, 42 containing the gas increases and causes a deformation of the elastic membrane 21, 22. The pressure in the chamber containing the gas increases in particular to 0.160 Bar.

[0116] The blood circulation chambers 31 , 32 are emptied and the blood is sent to the blood circulation circuits C1 , C2 (organs and lungs).

[0117] In the initial state of diastole, the chambers containing the gas each have a volume of approximately 130 mL, a pressure of approximately 0.160 Bar, the blood circulation chambers 31, 32 (artificial ventricles) are free of blood (or are at their lowest level), the distributor has been tilted, and the chambers containing the gas 41, 42 have just been connected to the first buffer container 51 (low pressure).

[0118] The pressure in the chambers 41 , 42 containing the gas drops (and then returns to 0.107 Bar) and causes a deformation of the elastic membranes 21 , 22 , resulting in an increase in the volume of the blood circulation chambers 31 , 32 .

[0119] The blood circulation chambers 31, 32 (artificial ventricles) are filled.

[0120] The system 1 according to the invention is configured so that the blood circulation chamber (artificial ventricle) is filled with a constant pressure, i.e. on average:

[0121] The blood circulation chamber of the first artificial chamber 11 (left artificial ventricle) is 0.012 Bar;

[0122] The blood circulation chamber of the second artificial chamber 12 (right artificial ventricle) is 0.005 Bar. At the end of diastole, the systole-diastole cycle can restart.

Claims

1. A system (1) for generating blood circulation in at least a part of an organ of a vertebrate, comprising a first artificial cavity (11) and a second artificial cavity (12), each of said cavities comprising a flexible membrane (21, 22) capable of beating under the action of a gas, each of said membranes sealingly separating a blood circulation chamber (31, 32) and a chamber (41, 42) containing said gas, It is characterized in that The system comprises: a first gas buffer container (51) intended to substantially reach a first pressure, referred to as low pressure, and a second gas buffer container (52) intended to substantially reach a second pressure, referred to as high pressure, higher than said first pressure; a gas distribution mechanism (6), comprising a 4-way 2-position valve (60), the 4-way 2-position valve being connected to a single tube, and then being connected to the gas-containing chambers of the first artificial cavity and the second artificial cavity through a branch tube and further connected to the first gas buffer container and the second gas buffer container, the gas distribution mechanism (6) being arranged to alternately and simultaneously inject gas into the two gas-containing chambers and simultaneously exhaust gas from the two gas-containing chambers, so as to synchronously provide a predetermined value of blood flow rate in the blood circulation chambers of the first artificial cavity and the second artificial cavity; A pneumatic pump (7) which is supplied with electrical energy and is installed between the first gas buffer container and the second gas buffer container and is intended to draw gas from the first gas buffer container to inject the gas into the second gas buffer container.

2. System (1) for generating blood circulation in at least a part of an organ of a vertebrate according to claim 1, characterized in that The first and second artificial cavities, the first and second gas buffer containers, the gas distribution mechanism and the pneumatic pump form a single-piece assembly, and the system also includes a battery for supplying electrical energy to the pump (7) and the gas distribution mechanism (6).

3. System (1) for generating blood circulation in at least a part of an organ of a vertebrate according to any one of claims 1 and 2, characterized in that The pump (7) is a vane pump (70).

4. System (1) for generating blood circulation in at least a part of an organ of a vertebrate according to any one of claims 1 to 2, characterized in that The gas distribution mechanism (6) comprises at least one piezoelectric switch and / or at least one shape memory switch and / or at least one electromagnetic switch.

5. System (1) for generating blood circulation in at least a part of an organ of a vertebrate according to any one of claims 1 to 2, characterized in that The gas is air.

6. System (1) for generating blood circulation in at least a part of an organ of a vertebrate according to claim 1, characterized in that The valve (60) is a flap valve and / or a pilot-operated slide valve.

7. System (1) for generating blood circulation in at least a part of an organ of a vertebrate according to any one of claims 1 to 2, characterized in that The system forms a total heart prosthesis intended to be implanted in the pericardial cavity of a patient and capable of replacing the left ventricle and the right ventricle of the patient after ablation of the left ventricle and the right ventricle of the patient, wherein a first artificial cavity and a second artificial cavity (11, 12) form a biventricular module, wherein the blood circulation chamber (31) of the first artificial cavity (11) is intended to be connected to the left atrium and the aorta of the patient, and the blood circulation chamber (32) of the second artificial cavity (12) is intended to be connected to the right atrium and the pulmonary artery of the patient.

8. System (1) for generating blood circulation in at least a part of an organ of a vertebrate according to any one of claims 1 to 2, characterized in that The system forms a circuit for extracorporeal perfusion of the organ, making it possible to keep the organ alive for transplantation.

9. System (1) for generating blood circulation in at least a part of an organ of a vertebrate according to any one of claims 1 to 2, characterized in that The system comprises one and only one pneumatic pump (7).

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