Artificial heart auxiliary device based on magnetically active soft material

Abstract

The invention discloses an artificial heart auxiliary device based on a magnetic active soft material, which belongs to the field of magnetic soft material application and comprises a simulation chamber part and an external driving part. Wherein the simulation chamber part is of a cylindrical structure composed of a front structural area, a rear structural area and an extrusion functional area between the front structural area and the rear structural area, inlet and outlet ends are connected with a left ventricle and an aorta respectively, and a one-way valve is installed in the simulation chamber part. Each part in the simulation chamber part is made of a mixed material of neodymium iron boron magnetic powder and polydimethylsiloxane, and is further connected by Ecoflex-0050 silica gel to form an integral structure, and the artificial ventricle auxiliary device capable of supplying blood in a pulsating manner can generate contraction movement under the driving of a one-way 30-50mT weak uniform magnetic field provided by the external driving part, so that the artificial ventricle auxiliary device capable of supplying blood in a pulsating manner is formed.

Description

Technical Field

[0001] The present invention belongs to the application field 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, Thoratec VAD, was later further developed into HeartMate I. The first generation of LVADs are mostly pneumatic, hydraulic and other pulsating blood pumps, and the working principle is similar to that of the natural heart. Representative products include HeartMate I, HeartMateXVE, Novacor, Berlin Heart EXCOR, etc. Because the single pumping volume of the pulsating pump is relatively fixed, the versatility between different individuals is weak. Adult males, adult females, and young children usually need to install assistive devices of different volumes. In addition, pneumatic pulsating pumps are often complex in structure, large in size, with a high overall failure rate, obvious noise, and high energy consumption, which have a significant impact on the patient's life.

[0004] The second-generation LVAD mainly changes from pneumatic / hydraulic drive to a motor-driven contact axial flow pump, with high-speed rotating blades driving blood in and out, greatly improving stability and reducing volume. There are a large number of axial flow pump LVAD products, and representative products include HeartMate II, Jarvik2000, Berlin Heart INCOR, Heart Assist 5, etc. Since motors are usually used instead of volumetric pumps, the second-generation LVAD usually has the advantages of excellent controllability, direct energy supply, and low failure rate. The blood pumping volume can be adjusted relatively simply by adjusting the motor speed, and it has good adaptability to different individuals and different movement states. However, there are problems such as motor suction, damage to blood cells, work heat generation, and non-pulsation of blood flow. The motor also has certain energy supply requirements, and usually needs to carry a power supply device with you, and the battery life is limited.

[0005] The third-generation LVAD is a fully suspended non-contact centrifugal pump. The blades are suspended in the working chamber by magnetic suspension or hydraulic suspension, thereby achieving contactless blood pumping. Its volume is roughly the same as or slightly larger than that of the second-generation motor-type axial flow pump, but it reduces the risk of wear, heat generation and damage to blood cells. Improvements have been made in avoiding thrombosis and enhancing the durability of the device. Representative products include HeartMate III, Heartware HVAD, etc. However, the current LVAD energy units are all located outside the body, and the wireless energy transmission method cannot provide enough power within the human safety range for the LVAD device to work properly. Therefore, wires must be used to enter the body for energy supply, which is prone to infection. After the third-generation LVAD is implanted, blood pressure is mainly generated by the blood pump. The blood flow is continuous but not constant throughout the cardiac cycle. There is blood output during the systole and diastole of the heart, so the blood rises during the diastole. The high and low pressure difference is only about 5mmHg, and the arterial pulse is approximately a straight line. Long-term non-pulsatile flow may cause potential physiological effects on patients. Summary of the invention

[0006] In order to overcome the deficiencies of existing ventricular assist devices in terms of energy supply into the body 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 pulsatility blood supply.

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

[0008] The simulation chamber part is a cylindrical structure consisting of a front structure area, a rear structure area and an extrusion functional area between the two. Among them, a one-way valve is set in the front structure area and the rear structure area; the one-way valve is a circular sheet structure composed of 4 sectors with a central angle of 90 degrees. A layer of silicone film made of Ecoflex0050 is laid on the wall of the overall simulation chamber part of the above structure.

[0009] The aforementioned extrusion functional area and the one-way valve are both made of magnetically active materials. The magnetically active material is a mixed material containing neodymium iron boron magnetic powder and polydimethylsiloxane. The magnetic material inside the extrusion functional area is pre-magnetized to a remanent magnetic saturation state by a strong magnetic field. By magnetizing in batches, the magnetic field direction of each part of the magnetic material is changed when it is magnetized so that the remanent magnetic directions of different areas are different. Different movements are generated under the action of a unidirectional uniform magnetic field, and the overall structural changes are formed by combined movements, with the shapes of the two ends maintained and the middle part contracted.

[0010] The part of each fan-shaped structure near the center of the circle in the one-way valve is magnetized, and the fan-shaped structures are driven to open upward as a whole under the action of the magnetic field; when the magnetic field is removed, the fan-shaped structures return to their original state. The one-way valve in the front structural area is used to simulate the aortic valve to prevent aortic backflow, and opens when the squeeze functional area contracts to allow blood to pass; the one-way valve in the rear structural area is used to simulate the mitral valve to prevent pulmonary vein backflow into the left ventricle, and opens when the squeeze functional area recovers.

[0011] The 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 in parallel 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 chamber part) composed of magnetic materials has good biocompatibility, strong stability, density and elastic energy close to those of human muscles, and has little impact on the human body;

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

[0015] 3. The artificial heart assist device based on magnetically active soft materials of the present invention has a low driving magnetic field, and the volume and mass of the magnetic field generating device are comparable to those of a smart phone, which is 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 artificial heart assist device of the present invention is based on magnetically active soft materials. The heat generation of the magnetically driven artificial heart is relatively low. The local temperature rise caused under normal working conditions is less than 0.5K, which is significantly lower than the temperature rise of about 2K of the current electrically driven pump artificial heart.

[0018] 6. The artificial heart assist device of the present invention is based on magnetically active soft materials. The blood flow generated by the magnetically driven artificial heart is pulsating, which is the same as the natural blood flow of the human body, and can avoid negative effects on tissues and organs such as blood vessels and valves;

[0019] 7. The artificial heart assist device based on magnetically active soft materials of the present invention has a relatively simple straight-cylinder chamber flow field 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 an artificial heart assist device based on magnetically active soft materials of the present invention;

[0021] Figure 2 The figure is a schematic diagram of the deformation of the extrusion functional area driven by magnetism in the artificial heart assist device based on magnetically active soft materials of the present invention.

[0022] In the figure:

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

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

[0025] 105-Connection structure DETAILED DESCRIPTION

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

[0027] The artificial ventricular assist device based on magnetically active soft materials of the present invention comprises a simulated chamber part 1 and an external driving part 2, wherein the simulated chamber part 1 is integrally arranged inside the left ventricle of the heart or outside the heart, and is connected to the aorta and the 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 front structure area 101 decreases gradually from bottom to top, and the diameter reduction ratio of the upper part is smaller than that of the lower part. The whole is funnel-shaped, and the outer wall is smoothly transitioned. The upper end of the front structure area 101 is used to connect to the aorta connecting pipe of the heart, and the inner diameter of the end face is the same as the inner diameter of the aorta connecting pipe; the lower end of the front structure area 101 is used to connect to the extrusion functional area.

[0030] The structure of the rear structural area 102 is the same as that of the front structural area 101. The cross-sectional diameter gradually decreases from top to bottom, and the upper diameter decreases at a greater rate than the lower diameter decreases, forming a funnel shape with a smooth outer wall transition. The lower end of the rear structural area 102 is used to connect to the left ventricle connecting pipe of the heart, and the inner diameter is the same as the inner diameter of the left ventricle connecting pipe; the upper end of the rear structural area 102 is used to connect to the extrusion functional area.

[0031] The extrusion functional area 103 is the core area of ​​the present invention, and is in a cylindrical structure, with the upper and lower ends having the same inner diameter as the lower end of the front structure area 101 and the upper end of the rear structure area 102 and connected to each other.

[0032] The one-way valve 104 is used to simulate the heart valve area, and is mainly used to prevent the blood from flowing back into the simulated chamber part 1. The one-way valve 104 is a circular sheet structure composed of two pieces 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; wherein, 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 front structure area 101 and the lower part of the rear structure area 102 respectively.

[0033] The extrusion functional area 103 and the one-way valve 104 are both made of magnetically active materials, and since it is necessary to ensure the consistency of the density, hardness and overall structure of the overall simulation chamber as much as possible, the same magnetically active material as the extrusion functional area 103 and the one-way valve 104 is still added to the materials in the front structure area 101 and the rear structure area 102. The magnetically active material is a mixed material containing neodymium iron boron magnetic powder and polydimethylsiloxane (PDMS). The preparation process is: put polylactic acid material into the 3D printer, and the 3D printer prints the mold according to the mold pre-modeled on the computer; then mix the magnetic powder and PDMS in a certain mass ratio, specifically, the mass ratio of the front structure area 101, the rear structure area 102 and the extrusion functional area 103 is 1:1, and the mass ratio of the two in the one-way valve is 2:1; stir until fully mixed. Finally, pour the unsolidified material after stirring into the mold, put it into a vacuum drying oven at room temperature to remove bubbles and solidify for 8 hours, and then demold it.

[0034] A connection structure 105 made of Ecoflex0050 silicone is provided between the front structural area 101, the rear structural area 102 and the extrusion functional area 103. The connection between the three is achieved through the connection structure 105, so that the simulation chamber part 1 is spliced ​​as a cylindrical structure, and it is necessary to ensure that the connection structure 105 is flush with the inner wall of the simulation chamber part 1 to avoid affecting the blood flow. Similarly, a connection structure 105 made of Ecoflex0050 silicone is provided between the front structural area 101, the rear structural area 102 and the one-way valve 104 to achieve the connection of 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 functional area 103, and 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] In the artificial ventricular assist device based on magnetically active soft materials of the present invention, the anterior structural area 101 and the posterior structural area 102 mainly play the role of connecting the inlet and outlet blood vessels and providing channels. Among them, the anterior structural area 101 is connected to the left ventricle through the left ventricle connecting pipe, so that blood flows out of the left ventricle and flows into the simulated chamber part 1, and the two are also connected by a connecting structure 105 made of Ecoflex0050 silicone. The posterior structural area 102 is connected to the aorta through the aorta connecting pipe, and the blood pumped out of the simulated chamber part 1 is sent to the aorta for systemic circulation. The two are also connected by a connecting structure 105 made of Ecoflex0050 silicone. The magnetic materials inside the anterior structural area 101 and the posterior structural area 102 are not magnetized, and the original funnel-shaped structure is maintained under the drive of the magnetic field.

[0036] The magnetic material inside the extrusion functional area 103 is pre-magnetized to a remanent magnetic saturation state by a strong magnetic field. By magnetizing in batches, the magnetic field directions of each part of the magnetic material are changed when magnetized so that the remanent magnetic directions of different regions are different, thereby generating different movements under the action of a unidirectional uniform magnetic field. Through the combined movement, an overall structural change is formed in which the shapes of the two ends are maintained and the middle part is contractible. The overall change is as follows: Figure 2 As shown, the squeezing functional area 103 can be contracted as needed to pump out blood.

[0037] The part of each fan-shaped structure close to the center of the circle in the two one-way valves 104 is magnetized, and the fan-shaped structures are driven to open upward as a whole under the action of the magnetic field; when the magnetic field is removed, the fan-shaped structures return to their original state, so that the fan-shaped structures are switched synchronously between opening and closing. Among them, the upper one-way valve opens when the extrusion functional area 103 contracts, allowing blood to pass through, and returns to the initial state after the magnetic field is removed, preventing blood from flowing back to the extrusion functional area 103 from the upper side. The lower one-way valve opens when the extrusion functional area 103 recovers, playing 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 functional area 103 works. Therefore, the mass ratio of magnetic powder in the material of the one-way valve 104 is higher (2:1), making the one-way valve 104 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 drive part 2. The external drive part 2 is a small magnetic field generator (similar in size and weight to a mobile phone), with the N pole placed on the front of the human chest and the S pole placed on the back of the human body. The two are placed in parallel and face each other. The magnetic field generator is powered by a button battery, including a main power battery and two backup batteries, and can work continuously for more than 24 hours. In the working state, a magnetic field with a constant direction and a sinusoidal change of magnetic induction intensity of 0 to 50mT 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 smaller magnetic field generating devices on the chest and back. The magnetic field generated by the generating device can penetrate the human body almost unimpeded to drive the artificial heart to beat periodically, thus solving the problem that the existing ventricular assist devices usually require percutaneous insertion of wires into the body and are non-pulsatile.

Claims

1. An artificial heart assist device based on magnetically active soft materials, characterized in that: It includes a simulation chamber part and an external driving part; The simulation chamber part is a cylindrical structure consisting of a front structure area, a rear structure area and an extrusion functional area therebetween; wherein a one-way valve is arranged in the front structure area and the rear structure area; the one-way valve is a circular sheet structure consisting 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 part; The extrusion functional area and the one-way valve are both made of magnetically active materials; the magnetically active material is a mixed material containing neodymium iron boron magnetic powder and polydimethylsiloxane; the magnetic material inside the extrusion functional area is pre-magnetized to a remanent magnetic saturation state by a strong magnetic field, and the magnetic field direction of each part of the magnetic material is changed by batch magnetization so that the remanent magnetic directions of different areas are different, and different movements are generated under the action of a unidirectional uniform magnetic field, and an overall structural change is formed by combined movement in which the shapes of the two ends are maintained and the middle part is contracted; The part of each fan-shaped structure near the center of the circle in the one-way valve is magnetized, and the fan-shaped structures are driven to open upward as a whole under the action of the magnetic field; when the magnetic field is removed, the fan-shaped structures return to their original state; The 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 in parallel and face each other.

2. An artificial heart assist device based on magnetically active soft materials as claimed in claim 1, characterized in that: The front structure area and the rear structure area are funnel-shaped as a whole, with smooth transition of the outer wall, and the large diameter section of the two is connected with the two ends of the cylindrical extrusion functional area.

3. An artificial heart assist device based on magnetically active soft materials as claimed in claim 1, characterized in that: 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 are not magnetized.

4. An artificial heart assist device based on magnetically active soft materials as claimed in claim 1, characterized in that: A connecting structure made of Ecoflex0050 silicone is arranged between the front structure area, the rear structure area and the extrusion functional area of ​​the simulation chamber part, and the connection among the three is achieved through the connecting structure.

5. An artificial heart assist device based on magnetically active soft materials as claimed in claim 4, characterized in that: The connecting structure is flush with a portion of the inner wall of the simulation chamber.

6. An artificial heart assist device based on magnetically active soft materials as claimed in claim 1, characterized in that: A connection structure made of Ecoflex0050 silicone is arranged 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.

7. An artificial heart assist device based on magnetically active soft materials as claimed in 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.

8. An artificial heart assist device based on magnetically active soft materials as claimed in 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.

9. An artificial heart assist device based on magnetically active soft materials as claimed in 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 to 50 mT is generated between the two poles.

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