An artificial heart assist device based on magnetically active soft material

Abstract

The application discloses a kind of artificial heart auxiliary device based on magnetic active soft material, belongs to magnetic soft material application field, including simulation chamber portion and external driving portion.Wherein, simulation chamber portion is by front, rear structure area and extrusion function area between the two constitute's cylindrical structure, inlet and outlet end are connected with left ventricle and aorta respectively, and inside is equipped with one-way valve.Simulation chamber portion each part is made of neodymium iron boron magnetic powder and polydimethylsiloxane mixed material, and further by Ecoflex-0050 silicone connection to form integral structure, can provide one-way 30~50mT weaker uniform magnetic field drive under external driving portion, generate contraction movement, form pulsatile blood supply artificial heart auxiliary device.

Description

Technical Field

[0001] The present invention belongs to the field of application of magnetic soft materials and is an artificial ventricular assist device with magnetically driven deformation, specifically an artificial ventricular assist device based on magnetically active soft materials. Background Art

[0002] At present, ventricular assist devices have undergone three generations of development, and five domestic ventricular assist devices have been approved for marketing, but each type of ventricular assist device still has its own problems.

[0003] The Left Ventricular Assist Device (LVAD) was first used in 1986. The device used this time, the Thoratec VAD, was later further developed into the HeartMate I. The first generation of LVADs were mostly pneumatic, hydraulic, and other pulsating blood pumps, and their working principles were similar to those of a natural heart. Representative products include HeartMate I, HeartMateXVE, Novacor, Berlin Heart EXCOR, etc. Since the single pumping volume of the pulsating pump is relatively fixed, it has weak versatility among different individuals. Adult men, adult women, and young children usually need to install assist devices of different volumes. In addition, pneumatic pulsating pumps are often complex in structure, large in size, have a high overall failure rate, are noisy, and have high energy consumption, which have a significant impact on the patient's life.

[0004] Second-generation LVADs primarily transition from pneumatic / hydraulic drive to a motor-driven contact axial-flow pump, with high-speed rotating blades driving blood in and out, significantly improving stability and reducing size. Axial-flow pump LVADs are available in a wide variety of models, including the HeartMate II, Jarvik 2000, Berlin Heart INCOR, and Heart Assist 5. Because motors typically replace positive displacement pumps, second-generation LVADs typically offer advantages such as excellent controllability, direct power supply, and low failure rates. Blood delivery can be easily adjusted by adjusting motor speed, making them highly adaptable to different individuals and exercise states. However, there are issues with motor suction, blood cell damage, heat generation, and non-pulsatile blood flow. Motors also require a certain amount of power, often requiring a portable power supply device, and their battery life is limited.

[0005] Third-generation LVADs are fully suspended, non-contact centrifugal pumps. The impellers are suspended within the working chamber through magnetic or hydraulic levitation, enabling contactless pumping. While their volume is roughly the same as or slightly larger than that of second-generation motor-driven axial-flow pumps, they reduce the risk of wear, heat generation, and blood cell damage. Improvements have been made to prevent thrombosis and enhance device durability. Representative products include the HeartMate III and Heartware HVAD. However, current LVAD energy units are external to the body. Wireless energy transmission methods cannot provide sufficient power within human safety limits for proper function of the LVAD device. Therefore, wires are required for power supply, which can easily lead to infection. After implantation, blood pressure is primarily generated by the pump. Blood flow is continuous but not constant throughout the cardiac cycle. Blood is pumped out during both systole and diastole, resulting in elevated blood flow during diastole. The differential between high and low pressure is only approximately 5 mmHg, and the arterial pulse is approximately a straight line. Long-term non-pulsatile flow may have potential physiological effects on patients. Summary of the Invention

[0006] In order to overcome the shortcomings of existing ventricular assist devices in terms of energy supply and pulsatility, the present invention proposes an artificial ventricular assist device based on magnetically active soft materials, which can be driven by a relatively low magnetic field and can provide pulsatile blood supply.

[0007] The invention discloses an artificial heart assist device based on magnetically active soft materials, comprising a simulation chamber part and an external driving part.

[0008] The simulation chamber is a cylindrical structure consisting of a front structural area, a rear structural area, and an extrusion functional area between them. The front and rear structural areas are equipped with one-way valves; these one-way valves are circular plates composed of four sectors with a central angle of 90 degrees. The walls of the entire simulation chamber are covered with a silicone film made of Ecoflex 0050.

[0009] The aforementioned extrusion functional area and one-way valve are both made of a magnetically active material. The magnetically active material is a mixture of neodymium iron boron magnetic powder and polydimethylsiloxane. The magnetic material within the extrusion functional area is pre-magnetized to a saturated remanent magnetic state using a strong magnetic field. By magnetizing the material in batches, the magnetic field direction is altered during magnetization, resulting in different remanent magnetic directions in different areas. This generates distinct movements under the influence of a unidirectional, uniform magnetic field. This combined movement results in an overall structural change in which the ends maintain their shape while the center contracts.

[0010] The sector-shaped structures in the one-way valve are magnetized near the center of the circle, causing the magnetic field to drive the entire sector to open upward. When the magnetic field is removed, the sectors return to their original state. The one-way valve in the anterior structural area simulates the aortic valve, preventing backflow from the aorta. It opens when the compression zone contracts, allowing blood to pass through. The one-way valve in the posterior structural area simulates the mitral valve, preventing backflow from the pulmonary veins into the left ventricle. It opens when the compression zone recovers.

[0011] The above magnetic field is provided by an external driving part, which is a small magnetic field generator. The N pole is placed on the front chest of the human body, and the S pole is placed on the back of the human body. The two positions are placed parallel to each other and face each other.

[0012] The advantages of the present invention are:

[0013] 1. In the artificial heart assist device based on magnetically active soft materials of the present invention, the artificial muscle (simulating the chamber portion) composed of magnetic materials has good biocompatibility, strong stability, and a density and elastic energy close to those of human muscle, thus having little impact on the human body;

[0014] 2. The artificial heart assist device of the present invention, based on magnetically active soft materials, has a strong ability to penetrate the human body through the magnetic field. It can be driven externally, avoiding the complicated operation and infection problems caused by inserting wires into the body.

[0015] 3. The artificial heart assist device based on magnetically active soft materials has a low driving magnetic field. The volume and mass of the magnetic field generating device are comparable to those of a smartphone, making it highly portable and easy to wear.

[0016] 4. The artificial heart assist device based on magnetically active soft materials of the present invention has a low energy consumption of the magnetic field generating device and can be powered by an external battery for a long time;

[0017] 5. The present invention's artificial heart assist device, based on magnetically active soft materials, generates low heat in a magnetically driven artificial heart. Under normal operating conditions, the local temperature rise caused is less than 0.5K, significantly lower than the approximately 2K temperature rise of current electrically driven pump-type artificial hearts.

[0018] 6. The present invention's artificial heart assist device, based on magnetically active soft materials, generates pulsatile blood flow, identical to the body's natural blood flow, thus avoiding negative impacts on blood vessels, valves, and other tissues and organs.

[0019] 7. The artificial heart assist device of the present invention is based on magnetically active soft materials, and the straight-cylinder chamber flow field is relatively simple and will not produce obvious turbulence. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure and position of the artificial heart assist device based on magnetically active soft materials of the present invention;

[0021] Figure 2 This is a schematic diagram of the deformation of the extrusion functional area in the artificial heart assist device based on magnetically active soft materials of the present invention under magnetic drive.

[0022] In the picture:

[0023] 1-Simulation chamber part 2-External drive part 101-Front structure area

[0024] 102-rear structure area 103-extrusion functional area 104-one-way valve

[0025] 105-Connection structure DETAILED DESCRIPTION

[0026] The present invention will be described in further detail below with reference to the accompanying drawings.

[0027] The present invention is based on an artificial ventricular assist device of magnetically active soft materials, comprising a simulated chamber portion 1 and an external driving portion 2, wherein the simulated chamber portion 1 is entirely arranged inside or outside the left ventricle of the heart and is connected to the aorta and left ventricle of the heart. Figure 1 shown.

[0028] The simulation chamber part 1 includes a front structure area 101, a rear structure area 102, an extrusion functional area 103, a one-way valve 104 and a connecting structure 105.

[0029] The diameter of the anterior structural region 101 decreases gradually from bottom to top, with the upper portion decreasing at a smaller rate than the lower portion, creating a funnel-shaped overall shape with a smooth outer wall. The upper end of the anterior structural region 101 connects to the heart's aortic connection cannula, with the same inner diameter as the aortic connection cannula. The lower end of the anterior structural region 101 connects to the extrusion functional area.

[0030] The structure of the posterior structural area 102 is identical to that of the anterior structural area 101. Its cross-sectional diameter gradually decreases from top to bottom, with the upper portion decreasing at a greater rate than the lower portion, forming a funnel-shaped structure with a smooth outer wall. The lower end of the posterior structural area 102 connects to the left ventricular connection cannula, which has the same inner diameter as the left ventricular connection cannula. The upper end of the posterior structural area 102 connects to the compression functional area.

[0031] The extrusion functional area 103 is the core area of ​​the present invention and has a cylindrical structure. Its upper and lower ends have the same inner diameter as the lower end of the front structural area 101 and the upper end of the rear structural area 102 and are connected.

[0032] The one-way valve 104 is used to simulate the heart valve area, mainly to prevent the backflow of blood into the simulated chamber part 1. The one-way valve 104 is a circular sheet structure composed of four sectors with a central angle of 90 degrees. The two one-way valves 104 are divided into an upper one-way valve and a lower one-way valve; the upper one-way valve is used to simulate the aortic valve to prevent aortic backflow; the lower one-way valve is used to simulate the mitral valve to prevent pulmonary vein backflow into the left ventricle; the structure of the area near the two one-way valves should be as simple as possible, without auxiliary structures and large curvature bends to prevent local turbulence; therefore, the upper one-way valve and the lower one-way valve are installed in the upper part of the anterior structural area 101 and the lower part of the posterior structural area 102 respectively.

[0033] The extrusion functional area 103 and the one-way valve 104 are both made of magnetically active materials. Because the density, hardness, and overall structural consistency of the entire simulated chamber must be maintained as much as possible, the same magnetically active material as used for the extrusion functional area 103 and the one-way valve 104 is also added to the materials used to create the front structural area 101 and the rear structural area 102. This magnetically active material is a mixture of neodymium iron boron magnetic powder and polydimethylsiloxane (PDMS). The preparation process is as follows: polylactic acid material is placed in a 3D printer, which then prints the mold based on a mold pre-modeled on a computer. The magnetic powder and PDMS are then mixed in a specific mass ratio—specifically, a 1:1 mass ratio for the front structural area 101, the rear structural area 102, and the extrusion functional area 103, and a 2:1 mass ratio for the one-way valve. The mixture is then stirred until thoroughly mixed. Finally, the unsolidified material is poured into a mold, placed in a vacuum drying oven for room temperature degassing and curing for 8 hours, and then demolded.

[0034] A connecting structure 105 made of Ecoflex 0050 silicone is located between the front structural area 101, the rear structural area 102, and the extrusion functional area 103. This structure connects the three components, forming the entire simulated chamber 1 into a cylindrical structure. This structure must be flush with the inner wall of the simulated chamber 1 to avoid affecting blood flow. Similarly, a connecting structure 105 made of Ecoflex 0050 silicone is located between the front structural area 101, the rear structural area 102, and the one-way valve 104, connecting the one-way valve 105. At the same time, a layer of silicone film made of Ecoflex0050 is further laid on the wall of the overall simulation chamber part 1 connected by the connecting structure 105 (including the inner and outer walls of the front structure area 101, the rear structure area 102 and the extrusion function area 103, as well as the fan-shaped walls of the two one-way valves) to enhance biocompatibility, isolate the simulation chamber part 1 containing magnetic powder from the human body environment, and assume the function of further connecting the various parts.

[0035] The present application is based on the artificial ventricular assist device of magnetic active soft material, the front structure area 101 and the rear structure area 102 mainly play the role of connecting into and out of the blood vessels, providing a channel. Among them, the front structure area 101 is connected to the left ventricle through the left ventricular connecting pipeline, so that the blood flows out of the left ventricle and flows into the simulation chamber part 1, and the two are also connected by the connecting structure 105 made of Ecoflex0050 silicone. The rear structure area 102 is connected to the aorta through the aorta connecting pipeline, and the blood pumped out of the simulation chamber part 1 is sent to the aorta for systemic circulation, and the two are also connected by the connecting structure 105 made of Ecoflex0050 silicone. The magnetic material inside the front structure area 101 and the rear structure area 102 is not magnetized, and remains the original funnel-shaped structure under the driving of the magnetic field.

[0036] The magnetic material in the extrusion function area 103 is magnetized to a residual magnetization saturation state by a strong magnetic field in advance. By batch magnetization, the direction of the magnetic field when magnetizing each part of the magnetic material is changed so that the residual magnetization directions of different regions are different, thereby generating different movements under the action of a uniform magnetic field in one direction. By combining the movements, the overall structure changes are formed, the overall changes are as shown in Figure 2 The extrusion function area 103 can be shrunk as needed, and the blood is pumped out.

[0037] The part close to the center of the two one-way valves 104 is magnetized, and under the action of the magnetic field, the whole of each sector structure is opened to the upper side; when the magnetic field is removed, each sector structure returns to its original state, thereby synchronously switching between opening and closing. Among them, the upper one-way valve opens when the extrusion function area 103 shrinks, allowing blood to pass, and returns to the initial state after the magnetic field is removed, preventing blood from flowing back to the extrusion function area 103. The lower one-way valve opens when the extrusion function area 103 recovers, and plays a role in controlling the flow direction. At the same time, in order to avoid affecting the pressure and stroke volume of the pumped blood, the one-way valve needs to be opened before the extrusion function area 103 works, so the mass ratio of magnetic powder in the one-way valve 104 is higher (2:1), so that the one-way valve 104 is more sensitive to the magnetic field.

[0038] The magnetic field required for the above-mentioned simulation chamber part to work is provided by the external driving part 2. The external driving part 2 is a small magnetic field generator (with a size and weight comparable to a mobile phone), and the N pole is placed on the front chest of the human body, and the S pole is placed on the back of the human body. The two are placed in parallel and correspond to the front. The magnetic field generator is powered by a button cell, including a main power supply battery and two backup batteries, which can work for more than 24 hours. In the working state, a magnetic field with a constant direction and a magnetic induction intensity of 0-50mT changes in a sinusoidal manner is generated between the two poles.

[0039] The present invention is an artificial heart assist device based on magnetically active soft materials. When in use, the patient can wear a small magnetic field generator on the chest and back. The magnetic field generated by the generator can penetrate the human body almost unimpeded, driving the artificial heart to beat periodically, solving the problems of existing ventricular assist devices that usually require percutaneous insertion of wires and are non-pulsatile.

Claims

1. An artificial heart assist device based on magnetically active soft materials, characterized by: Including simulation chamber part and external driving part; The simulation chamber is a cylindrical structure consisting of a front structural area, a rear structural area, and an extrusion functional area between the two. The front and rear structural areas are funnel-shaped as a whole, with smooth outer walls. The large diameter sections of the two areas are connected to the two ends of the cylindrical extrusion functional area. One-way valves are installed in the front and rear structural areas. The one-way valves are circular sheet structures composed of four sectors with a central angle of 90 degrees. A layer of silicone film made of Ecoflex0050 is laid on the wall of the entire simulation chamber. The extrusion functional area and the one-way valve are both made of a magnetically active material; the magnetically active material is a mixture of neodymium iron boron magnetic powder and polydimethylsiloxane. The magnetic material inside the extrusion functional area is pre-magnetized to a remanent magnetic saturation state in a strong magnetic field. By magnetizing the magnetic material in batches, the magnetic field direction of each part of the magnetic material is changed during magnetization, so that the remanent magnetic direction of different areas varies. Under the action of a unidirectional uniform magnetic field, different movements are generated. Through the combined movement, an overall structural change is achieved in which the shape of the two ends is maintained and the middle part contracts. The fan-shaped structures in the one-way valve are magnetized near the center of the circle. Under the action of the magnetic field, the fan-shaped structures are driven to open upward as a whole. When the magnetic field is removed, the fan-shaped structures return to their original state. The magnetic field is provided by an external drive part, which is a small magnetic field generator. The N pole is placed on the front of the human chest and the S pole is placed on the back of the human body. The two positions are placed parallel and face each other. The front structure area and the rear structure area are made of the same material as the extrusion functional area; the magnetic materials inside the two areas are not magnetized.

2. The artificial heart assist device based on magnetically active soft materials according to claim 1, characterized in that: A connecting structure made of Ecoflex0050 silicone is provided between the front structure area, the rear structure area and the extrusion functional area of ​​the simulation chamber part, and the connection between the three is achieved through the connecting structure.

3. The artificial heart assist device based on magnetically active soft materials according to claim 2, characterized in that: The connecting structure is flush with a portion of the inner wall of the simulation chamber.

4. The artificial heart assist device based on magnetically active soft materials according to claim 1, characterized in that: A connecting structure made of Ecoflex0050 silicone is provided between the front structure area, the rear structure area and the connection position of the one-way valve to realize the connection of the one-way valve.

5. The artificial heart assist device based on magnetically active soft materials according to claim 1, characterized in that: The one-way valve in the front structural area opens when the extrusion functional area contracts; the one-way valve in the rear structural area opens when the extrusion functional area recovers.

6. The artificial heart assist device based on magnetically active soft materials according to claim 1, characterized in that: The mass proportion of magnetic powder in the one-way valve manufacturing material is higher than that in the extrusion functional area.

7. The artificial heart assist device based on magnetically active soft materials according to claim 1, characterized in that: In the external driving part, when the two magnetic field generators are in working state, a magnetic field with a constant direction and a sinusoidal change of magnetic induction intensity of 0~50mT is generated between the two poles.

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