Magnetically-driven ventricular assist apparatus for assisting heart beating

Abstract

The present invention pertains to the technical field of medical assist apparatuses. Disclosed is a magnetically-driven ventricular assist apparatus for assisting heart beating. The apparatus comprises two parts: an apparatus main body and an extension column. The apparatus main body is a mesh sleeve structure resembling a heart, the inner diameter of the apparatus main body decreases from top to bottom, the bottom of the apparatus main body is a circular surface, and a circumferential surface of the apparatus main body is formed by the interlacing of warp tubular columns and multiple weft tubular columns. The apparatus is made by mixing isotropic neodymium-iron-boron magnetic particles and a soft rubber material, and is a solid / hollow structure. When the apparatus is a solid structure, the apparatus can be wirelessly implanted in a body, enabling magnetically-driven heart beating under an external magnetic field, thereby assisting a failing heart to pump blood to achieve a therapeutic effect. When the apparatus is a hollow structure, by filling the hollow tube with a magnetic fluid and / or a drug, the apparatus can be endowed with magnetism while the synergistic therapeutic effect with the drug can be exerted, and fluid pressure power can also be provided for the heart. Therefore, the apparatus can exert a multi-modal synergistic therapeutic effect for treating various types of heart diseases, especially capable of producing positive, active, and multi-modal treatment for dilated ventricles of patients with advanced heart failure, thereby limiting heart dilation, and promoting heart rehabilitation.

Description

Magnetic drive assisted ventricular assist device for assisting heart beat TECHNICAL FIELD

[0001] The present application relates to the technical field of medical auxiliary devices, in particular to a direct ventricular assist device for assisting heart beat driven by magnetic force. BACKGROUND

[0002] Heart failure is a complex clinical syndrome caused by abnormal structure or function of heart, which results in impaired ventricular filling or ejection capacity. It is a serious disease that endangers human life and health. Traditional drug therapy for heart failure has certain limitations, and the problem of heart donor shortage is also difficult to be well solved. Therefore, in order to improve the survival rate of patients and prolong their waiting time for suitable heart source, a ventricular assist device for assisting heart beat has been born and developed.

[0003] Implanting a ventricular assist device (VAD) in vivo is one of the main means for treating patients with end-stage heart failure. The principle is to restore blood circulation for the failing heart through the work of the pump, or to assist blood pumping on the surface of the heart without contacting blood. The ventricular assist device driven by the pump to restore blood circulation of the heart can generate a large compression force, but since it needs to be in complete contact with blood, long-term use by patients can cause complications such as thrombosis and infection. Based on these problems, patients need to take anticoagulants and anti-infective drugs for a long time, which undoubtedly will increase the burden of patients.

[0004] The most studied non-blood contact ventricular assist device at present mostly adopts a gas pump or liquid pump system, such as a soft robot sleeve device. The device mainly includes a gas pressure transmission device, a gas pump and a soft sleeve. The above-mentioned device mainly utilizes compressed air to drive the soft sleeve to compress and rotate, and then simulates the movement of a normal human heart. Transmission between the compressed air source and the compression unit needs to pass through a hose on the skin. The working principle of the liquid pump system is similar, that is, the traditional non-blood contact device relying on gas or liquid cannot be implanted wirelessly in a true sense, and still cannot avoid the risk of infection.

[0005] In order to solve the problem of infection, the skilled in the art designed a ventricular assist device operated in the form of magnetic drive, which can reduce the blood compatibility problem caused by blood contact and reduce the risk of infection. As one of the magnetic activation patch devices (Adv Sci (Weinh), 2020. 8(1): p. 2000726.) has been reported, the device mainly includes: neodymium iron boron magnet, external coil, by attaching four pieces of neodymium iron boron magnet on the epicardial surface of four different positions, under the action of external coil, the magnetic drive heart pumping blood is realized. Although this device can realize non-blood contact, wireless auxiliary heart pumping in vivo, but the single piece of neodymium iron boron magnet weighs 83 g, and it needs to be sutured on the surface of myocardium for fixation, whether it is the heavy magnet or this invasive patch, it will undoubtedly cause great burden to the failing heart.

[0006] Chinese patent CN 116808429A discloses a non-blood contact type magnetic power ventricular assist device, which mainly comprises a power supply device, a pressure assist device and a control system. The pressure assist device comprises a fixed support, a multi-turn coil and a magnet. The fixed support comprises a shell and an extruded film. A plurality of magnets penetrate the shell, and the multi-turn coil is sleeved on the plurality of magnets. The patent uses a magnetic coupling resonance type wireless power supply energy transmission device to make the pressure assist device on the surface of the heart pulsate to achieve auxiliary blood pumping by extruding the ventricle. However, there are several obvious deficiencies if the device is actually put into use: first, the fixed support is designed in a full wrapping shape, which is easy to cause cardiac effusion deposition during use; second, the magnets are inlaid in the shell of the fixed support, which also makes the whole device heavy and increases the burden on the heart; third, the above-mentioned ventricular assist device is difficult to be combined with other heart failure treatment methods, especially cannot be used for direct drug intervention, which has obvious single and limitation in use.

[0007] In summary, the existing magnetic drive ventricular assist device still has many problems affecting the curative effect, which limits the clinical application of such devices, and the skilled in the art needs to make further scientific and reasonable improvements to make up for the corresponding deficiencies. SUMMARY

[0008] The purpose of the present application is to solve the problems in the prior art, and to provide a direct ventricular assist device for magnetic drive auxiliary heart beating, which is a multi-modal and multi-interventional ventricular assist device. It can provide magnetic drive and wireless treatment for patients to avoid complications, and can also combine drugs, magnetic drive and active fluid pressure power to achieve targeted sequential treatment of clinical symptoms for patients.

[0009] In order to achieve the above technical purposes, the present application is realized by the following technical scheme: the magnetic drive auxiliary heart beating ventricular assist device, the ventricular assist device comprises a device main body and an extension column two parts; the device main body is made according to the heart parameter, and is supported on the epicardial surface in working time; the extension column is used for connecting the device main body in the body and other accessory parts outside the body; the device main body is a mesh structure similar to the heart, the inner diameter thereof is reduced from top to bottom, the bottom surface of the device main body is a circular surface, the peripheral surface of the device main body is composed of a plurality of warp tube columns and a plurality of weft tube columns, and the peripheral surface presents a hollow mesh shape; the ventricular assist device is prepared by mixing isotropic neodymium iron boron magnetic particles and soft glue material.

[0010] Further, the average diameter of the isotropic neodymium iron boron magnetic particles is 1-5 μm; the soft glue material is thermoplastic elastomer (TPE) material, EcoflexTM 00-10 type soft silicone rubber or HY-Q series two-component addition type organic silicon material; the mass ratio of the isotropic neodymium iron boron magnetic particles and the soft glue material is 1:1.

[0011] Further, the extension column is arranged at the large-diameter end of the device main body.

[0012] As one of the examples, the warp tube column, the weft tube column and the extension column are all solid structures.

[0013] As another example, the warp tube column, the weft tube column and the extension column are all hollow structures and the interiors of the three are interconnected, and a supply hole communicating with the interior of the extension column is arranged at the top of the extension column.

[0014] Further, a plurality of micropores are uniformly distributed on the inner surfaces of the warp tube column and the weft tube column, and a selective filter membrane is arranged at the micropore.

[0015] Further, the diameters of the warp tube column and the weft tube column are the same, and the diameter of the micropore is less than 1 / 2 of the diameter of the warp tube column or the weft tube column.

[0016] Further, the extension column is connected with the pressure pump system or the drug delivery system outside the body through the supply hole thereon, so as to infuse liquid medicine or magnetic fluid into the interiors of the warp tube column and the weft tube column; when the liquid medicine is infused into the interiors of the warp tube column and the weft tube column, the medicine in the interiors of the tube columns can be released on the surface of the heart in one direction through the selective filter membrane by pressurizing the interiors of the tube columns by the pressure pump system; when the magnetic fluid is infused into the interiors of the warp tube column and the weft tube column, the magnetic fluid is uniformly retained in the device main body without overflowing out of the device main body, and the magnetic drive treatment can be performed after the magnetic activation device.

[0017] Further, a biocompatible coating is coated on the outer surface of the ventricular assist device, and as a preferred, a polyurethane material with good biocompatibility and excellent mechanical properties can be coated on the outer surface of the device.

[0018] The beneficial effects of the present application are:

[0019] 1. The device body of the ventricular assist device disclosed in the present application is designed based on actual heart parameters, and is a mesh structure similar to a heart. The peripheral surface of the device body is composed of a plurality of warp columns and weft columns and is in a hollow grid shape. After the device is implanted in a living body, the device body closely adheres to the epicardial surface of the heart, can provide physical support for the diseased heart, limit the adverse remodeling and expansion of the diseased heart, maintain the basic shape of the heart, and the hollow design will not cause the problem of fluid retention in the heart;

[0020] 2. The ventricular assist device disclosed in the present application can be implanted in a living body through minimally invasive surgery. When the device is a solid structure, it can be completely implanted wirelessly in the body. As a "second body cavity", it is attached to the surface of the heart, so that the device is completely independent of the outside world and the heart, and only relies on the magnetic field of the outside world to exert the magnetic driving effect, drive the device body to deform, and then actively "help" the failing heart to pump blood, avoiding the problems of infection caused by tethered implantation and thrombosis caused by direct contact with blood;

[0021] 3. The ventricular assist device disclosed in the present application is made of a mixture of magnetic material and soft rubber material. When the device is a solid structure, since the device has magnetism, only a magnetic field needs to be provided from the outside when magnetic therapy is performed, without the need for additional power pumps and line connections, so that wireless and magnetic driving treatment effects can be achieved, avoiding the problems of line infection caused by existing left ventricular assist heart pumps and the inconvenience of patients carrying power supply devices after surgery. In addition, the magnetic field is controllable, and the size of the magnetic driving force can be remotely and wirelessly controlled by adjusting parameters such as the size and frequency of the external magnetic field, which is convenient to operate;

[0022] 4. Since the ventricular assist device disclosed in the present application has good flexibility, it will not cause damage to the heart during magnetic driving deformation due to excessive rigidity, so that the heart loses the ability to beat and deform;

[0023] 5. The ventricular assist device disclosed in the present application has a relatively light weight, and will not cause additional burden to the failing heart during use;

[0024] 6. When the ventricular assist device is designed with a hollow structure and has micropores with selective filtration membranes on its inner surface, the hollow channels of the device can be filled with various therapeutic drugs and / or magnetic fluids. When the device is filled with liquid drugs, under the pressure of the power pump, various interventional drugs can be directly and targetedly delivered to the patient's diseased heart, allowing the drugs to be slowly released on the surface of the heart and exert a synergistic therapeutic effect. When magnetic fluids are infused into the hollow channels without pressure, the magnetic fluids can reside uniformly in the hollow channels, and then the device can be magnetically activated for magnetically driven therapy. Although this ventricular assist device cannot achieve completely wireless magnetically driven therapy, it increases the device's therapeutic modes. It can achieve targeted sequential treatment of clinical symptoms for patients through drug + magnetic drive + active fluid pressure dynamics. It can be used to treat various types of heart diseases, especially for dilated ventricles in patients with advanced heart failure, producing positive, active, and multimodal treatment, limiting cardiac dilation, and promoting cardiac rehabilitation. Attached Figure Description

[0025] Figure 1 is a schematic diagram of the structure of a solid internal magnetically driven ventricular assist device that helps the heart beat.

[0026] Figure 2 is a schematic diagram of the structure of a hollow, magnetically driven ventricular assist device that helps the heart beat.

[0027] Wherein, 1-the main body of the device, 2-the extension column;

[0028] 11-Meridian tube, 12-Latitude tube, 13-Micropore.

[0029] Detailed Implementation

[0030] The following embodiments further illustrate the content of the present invention, but should not be construed as limiting the present invention. Any modifications and substitutions made to the methods, steps, or conditions of the present invention without departing from the essence of the invention are within the scope of the present invention.

[0031] Example 1: Fabrication of a solid, magnetically driven ventricular assist device for assisted cardiac pulsation

[0032] The structure of the ventricular assist device to be prepared in this embodiment is shown in Figure 1. The device includes two parts: the main body 1 and the extension column 2. The extension column 2 is located on the top of the main body 1, and the axis of the extension column 2 is parallel to the axis of the main body 1. Both the main body 1 and the extension column 2 are solid structures inside.

[0033] In actual use, the extension column 2 is fixed inside the muscle at the wound site of the organism, thereby fixing the main body 1 of the device in the body; the main body 1 of the device is designed according to the actual size of the heart, and in use, it provides physical support to the diseased heart and performs other functions by closely adhering to the surface of the epicardium.

[0034] The device body 1 is similar to the half-fusiform shape of the heart and is hollow inside, and the inner diameter thereof is gradually reduced from top to bottom. The bottom surface of the device body 1 is circular, and the circumferential surface of the device body 1 is formed by the interlaced warp pipe columns 11 and weft pipe columns 12, and the entire surface presents a mesh-like hollow grid, which is helpful to solve the problem of cardiac effusion.

[0035] In the embodiment, the number of the extension column 2 is one, but the number of the extension column 2 can be increased or decreased according to the actual situation, and the corresponding number of changes should not be regarded as a limitation to the technical features.

[0036] The ventricular assist device is prepared by injection molding. The device body 1 and the extension column 2 are mixed and injected by a magnetic material and a soft glue material, and then are cured and shaped by heating. After curing and shaping, a layer of medical polyurethane polymer is coated on the outer surface of the device. The polyurethane layer can make the surface of the device smoother and not easy to adhere to impurities, and also meets the requirement of biocompatibility, so that the device will not cause incompatibility problem when contacting with the heart.

[0037] The specific process of preparing the ventricular assist device with a solid inside by injection molding is as follows:

[0038] 1. Before molding, the parameters such as the shape, size, chest cavity space, rib shape and position of the heart are determined by electronic computed tomography. According to the size of the heart, a mold for the auxiliary device is made from polytetrafluoroethylene.

[0039] 2. Select isotropic neodymium-iron-boron magnetic particles with an average diameter of 5 μm. According to the mass ratio of 1:1, neodymium-iron-boron magnetic particles and soft silicone rubber (Ecoflex™ 00-10 type, Ecoflex™ silicone rubber weight or volume mixing ratio is 1A:1B, and is cured at room temperature, and the shrinkage rate is negligible. Smooth-On company), the soft silicone rubber and the neodymium-iron-boron magnetic particles are fully stirred and mixed at room temperature to prepare a magnetic silicone precursor;

[0040] 3. Pour the magnetic silicone precursor into the polytetrafluoroethylene mold prepared in step 1, and cure at room temperature for 4 h;

[0041] 4. After curing and shaping, the mold is removed, and the desired ventricular assist device is obtained. The device is placed in a double coil system for magnetization, and the device is activated by magnetism.

[0042] 5. A layer of medical polyurethane coating (material information: Hymedix AI12 AR35 CR104 FR103 FI520) is coated on the surface of the activated ventricular assist device to enhance the biocompatibility of the device.

[0043] The overall shape of the device body 1 part of the ventricular assist device formed by one-piece injection molding is similar to a heart, and an extension column 2 is arranged thereon.

[0044] Based on the above method, the heart of a rat is used as a template to prepare the device, and the size of the long axis and short axis of the rat heart and other parameters are measured to obtain the specific parameters of the heart. Then, the rat ventricular assist device is actually prepared according to the above method. The number of warp pipe columns 11 of the prepared ventricular assist device is 8, the number of weft pipe columns 12 is 4; the diameter of the extension column is 2 mm, the height is 10 mm; the inner diameter of the top of the device body part is 13 mm, the outer diameter is 15 mm; the outer diameter of the bottom small circle is 3 mm, the cross-sectional diameter of the warp pipe column 11 and the weft pipe column 12 is 1 mm, and the height of the device body is 15 mm.

[0045] The weight of the above prepared rat ventricular assist device is 0.9802 g.

[0046] The material parameters of the obtained device are as follows:

[0047] The physical performance indicators of the material are: breaking strength: 22±3 MPa, compression strength: 65.5±7.7 MPa, elastic modulus: 78.87±10.39 kPa, and magnetization: 61.3 kA / m.

[0048] The biological performance and indicators of the material are: cytotoxicity III; the non-adhesive connection time of the material and the heart tissue is ≥3 months; the permeability is 0 within 6 months.

[0049] External coil parameters: provide magnetic field (other parameters such as magnetic field size, frequency, coil turns, etc. are customized according to patient clinical symptoms)

[0050] Selection of magnetic drive magnetic field:

[0051] After the ventricular assist device is made, the external magnetic field mainly provides magnetic power for it, and by adjusting the frequency, strength, coil and other parameters of the magnetic field, the size of the magnetic field can be controlled to provide magnetic driving force for the device.

[0052] In order to find a suitable magnetic driving magnetic field, and at the same time observe the motion path and deformation effect of the device under the action of magnetic driving. First, explore the magnetic field in vitro, aiming to find a suitable environmental magnetic field.

[0053] In order to ensure that the ventricular assist device is simultaneously parallel to the axial direction of the device body 1 at any point on the device body 1 when it needs to contract, and that the device body 1 at any point is synchronized to expand in the opposite direction when it needs to relax, the three-dimensional Helmholtz coil is particularly selected to perform this task in this embodiment.

[0054] The model parameters of the three-dimensional Helmholtz coil used in this embodiment are: 3HLY7.5-100 type three-dimensional alternating magnetic field coil, three-dimensional magnetic field direction; frequency 10 Hz. The above-mentioned rat ventricular assist device is placed in the center of the three-dimensional Helmholtz coil, and the frequency and magnetic field size of the three-dimensional Helmholtz coil are adjusted by using a signal generator (model: DG1022Z). After many experimental tests of the dynamic movement of the device under different coil parameters, a suitable coil frequency and size interval is selected through the dynamic movement of the device under different magnetic fields.

[0055] In vitro test under the selected suitable magnetic field interval, implant the device on the surface of the euthanized rat heart through minimally invasive surgery, expose the entire rat chest cavity. Adjust the selected suitable interval range in vitro by using a signal generator (model: DG1022Z), observe the amplitude of the device driven by the magnetic field to assist the heart beat, and through multiple experiments, the best parameters of the device driven by the magnetic field to assist the heart beat are finally determined as: 200 mT, 3 Hz. Implant the device on the surface of the rat heart, and under different parameter conditions, the device does not occur disordered movement in torsion or displacement, which indicates that the implantation of the device does not produce other harmful effects under the action of the in vitro magnetic field, and the device can orderly contract and relax.

[0056] Application example, magnetic drive animal experiment

[0057] 1. Experimental materials

[0058] Experimental animals: 16 SPF male SD rats aged 6-8 weeks, weighing 200-220 g, purchased from Jiangsu Huacheng Xinnuo Pharmaceutical Technology Co., Ltd., license number SCXK (Su) 2020-0009.

[0059] 1.1 Experimental reagents:

[0060]

[0061] 1.2 Experimental instruments

[0062]

[0063] 2. Experimental method

[0064] 2.1 Animal grouping

[0065] Sixteen SD rats (200-220 g, male) were randomly divided into 4 groups: blank control group (Control group), model group (Model group), two treatment groups (Treatment group); two treatment groups were killed at 4 h, 24 h for sampling.

[0066] 1) Control group: blank control group, no treatment.

[0067] 2) Model group: myocardial infarction model was established, no treatment.

[0068] 3) Treatment (4 h): after modeling, implanting the ventricular assist device (MASD) prepared according to the method described in Example 1, wireless, magnetic drive treatment for 15 min at 3.5 h, and killing at 4 h.

[0069] 4) Treatment (24 h): after modeling, implanting the MASD prepared according to the method described in Example 1, wireless, magnetic drive treatment for 15 min at 3.5 h and 23.5 h, and killing at 24 h.

[0070] 2.2 Disease model establishment

[0071] All rats were weighed, and 10% chloral hydrate 0.3 g / kg was intraperitoneally injected to anesthetize the rats. After the rats were anesthetized, the chest was opened by invasive surgery, a 2-3 cm longitudinal opening was made at the right of the midline of the sternum using ophthalmic scissors, the skin and muscle were bluntly separated with hemostatic forceps, and then the muscle was opened and fixed with an eyelid opener to form a surgical field. After observing the stable respiration of the rat, the hemostatic forceps were bluntly inserted from the third and fourth intercostal spaces, and then the ophthalmic scissors were used to make a minimally invasive opening to expose the beating heart in the surgical field. At this time, the left hand used tweezers to gently pull apart the muscle layer, and the right hand held tweezers to gently tear the pericardium on the surface of the heart, paying attention to gentle movements and not damaging other organs. Then the position of the left coronary vein of the heart was found, and the left coronary artery was parallel to the position of the vein, and 6.0 suture was used to ligate the left anterior descending branch (LAD) at 1-2 mm below the left auricle. The occurrence of acute myocardial infarction was confirmed by color change of the ischemic area of the heart and characteristic changes of electrocardiogram. The sham operation group was not ligated but threaded, and the rest of the operation was the same as before.

[0072] 2.3 Implantation of device

[0073] The implantation of the device uses invasive minimally invasive thoracotomy, the sterilized ventricular assist device is squeezed and folded into the rat heart apex, and after reaching the apex, the device is unfolded, the extension column of the device is clamped with forceps, and the device is sleeved from the apex to the bottom of the heart. The process must be gentle to avoid damaging other organs. The extension column is introduced from the second and third intercostal spaces of the rat and fixed in the pectoral muscle. After all the work is done, the muscle layers are sutured layer by layer, and attention is paid to aspirate the air in the rat chest to form a negative pressure in the chest to help the rat recover spontaneous breathing. After the operation, the rat is placed on a heating plate to keep the rat's body temperature to prevent postoperative hypothermia.

[0074] 2.4 Magnetic driving heart beat therapy

[0075] After the device is implanted in the rat, the method described in Example 1 is used to provide a magnetic field environment of 200 mT, 3 Hz by using an external magnetic field to provide wireless, magnetic driving heart beat.

[0076] 3 Experimental results

[0077] 3.1 Echocardiography results

[0078] The changes of LVEF, LVFS, LVIDs and LVIDd values of rats in each group are as follows

[0079]

[0080] Note: The data of each group is represented by mean ± standard deviation (Mean ± SD). representing compared with the Model group, ; ; )

[0081] From the above data, it can be seen that the LVEF% (left ventricular ejection fraction) value and LVIDs (left ventricular end-systolic diameter) value of the Treatment (4 h) group (P<0.01) and the Treatment (24 h) group (P<0.05) compared with the Model group, there is a significant increase; the LVFS% (left ventricular fractional shortening) value of the Treatment (4 h) group compared with the Model group is significantly increased (P<0.05).

[0082] 3.2 Hemodynamic results

[0083] The LVSP (left ventricular systolic pressure), LVEDP (left ventricular end-diastolic pressure), +dp / dtmax (left ventricular maximum rising rate), -dp / dtmax (left ventricular maximum falling rate) values of rats in each group are as follows:

[0084]

[0085] Note: The data of each group is expressed by mean ± standard deviation (Mean ± SD). representing compared with the Model group, <0.0.5)

[0086] From the above data, the Treatment (24 h) group (P<0.05) compared with the Model group, LVSP value exists significant increase. LVSP as the main power of the heart to the artery, using the device for wireless, magnetic drive treatment, LVSP value of heart failure rats after myocardial infarction significantly increased, increased the ejection fraction of the heart.

[0087] 3.3 Experimental conclusion

[0088] The application example is characterized by the data of echocardiography and hemodynamics, and the experimental results show that the internal solid ventricular assist device prepared by the method disclosed in embodiment one can significantly improve the LVEF%, LVFS%, LVIDs and LVSP value of heart failure rats after myocardial infarction. It is proved that the device has clinical feasibility, and the concept of wireless and magnetic drive of the device is verified.

[0089] The ultrasound data shows that the magnetic drive treatment improves the ejection fraction of heart failure rats after myocardial infarction by 16.5%, and the left ventricular short axis shortening rate by about 27.6%. The hemodynamic results show that the left ventricular systolic pressure of myocardial infarction rats is increased by 17.3% after 15 min of magnetic drive treatment. The above indexes prove the clinical treatment feasibility of the wireless and magnetic drive of the device, and the magnetic drive can significantly improve the heart function of infarction rats, reduce the afterload of the heart, and increase the cardiac pump of heart failure rats.

[0090] Preparation of internal hollow multi-modal ventricular assist device

[0091] In order to make the ventricular assist device play a multi-modal synergistic treatment effect, such as treating end-stage heart failure patients with magnetic drive treatment while synergizing with drugs to achieve the purpose of improving the curative effect, the structure of the ventricular assist device is further adjusted in this embodiment compared with embodiment one.

[0092] Specifically, the structure of the ventricular assist device to be prepared in this embodiment is shown in Figure 2. The ventricular assist device disclosed in this embodiment includes a device main body 1 and an extension column 2. The extension column 2 is arranged at the top of the device main body, the axis of the extension column 2 is parallel to the axis of the device main body 1, and the device main body 1 and the extension column 2 are both hollow structures.

[0093] In actual use, the extension column 2 is fixed in the muscle at the wound of the organism, and then the device body 1 is fixed in the body; the device body 1 is designed according to the actual size of the heart, and when used, it provides physical support for the diseased heart by closely adhering to the epicardial surface and realizes other functions.

[0094] The device body 1 is in a semi-fusiform shape similar to a heart and is hollow inside, the inner diameter of which decreases from top to bottom, the bottom surface of the device body 1 is circular, and the circumferential surface of the device body 1 is composed of a plurality of warp tube columns 11 and a plurality of weft tube columns 12, which are staggered and present a hollow grid shape as a whole, and the hollow structure helps to solve the problem of cardiac effusion;

[0095] The warp tube column 11, the weft tube column 12 and the extension column 2 are all hollow structures and are interconnected inside, a plurality of micro-holes 13 are arranged on the inner side surface of the warp tube column 11 and the weft tube column 12 and are communicated with the inside of the tube column, a selective filter membrane is arranged at the micro-hole 12, which plays a role similar to the mitral valve between the left atrium and the left ventricle, can selectively permeate liquid in one direction, and a supply hole (not shown in the figure) is arranged at the top of the extension column 2 and is communicated with the inside of the extension column 2, so that the device can be filled with drugs and / or magnetic fluid (for example, superparamagnetic iron oxide nanoparticles (SPIO), purchased from WEISTRON company) from the outside of the body to the inside of the device, so that the device can not only be driven by magnetism for treatment, but also can be used for drug treatment, and can also provide fluid pressure power for the diseased heart, so that the device can exert multi-modal synergistic effect.

[0096] The above-mentioned internal hollow ventricular assist device is made by the wax dissolution method, the device body 1 and the extension column 2 are formed by wrapping the mixed magnetic material and soft glue material outside the wax mold, and the outer surface of the formed device body 1 and the extension column 2 is coated with polyurethane polymer to improve the biocompatibility of the device.

[0097] The specific preparation steps of the internal hollow ventricular assist device prepared by the wax dissolution method are as follows:

[0098] 1. Before molding, the parameters such as the shape, size, chest cavity space, rib shape and position of the heart are determined by electronic computed tomography;

[0099] 2. The blue wax model of the device is printed by DLP 3D printing through cooperation with the company (Wuhan San Di Intelligent Technology Co., Ltd.);

[0100] 3. Selecting isotropic neodymium-iron-boron magnetic particles with an average diameter of 5 μm, HY-Q series two-component addition type silicone material, model Q625 (Hongyejie Technology Co., Ltd.);

[0101] 4. Take the silicon material A component and the silicon material B component according to a mass ratio of 1:1, first put the silicon material A / B component into a container and fully stir and mix at room temperature, then mix the mixed silicon material with isotropic neodymium-iron-boron magnetic particles according to a mass ratio of 1:1 to prepare a magnetic silica gel component;

[0102] 5. Uniformly apply the magnetic silica gel component prepared in the above step to the surface of the 3D blue wax model, place the 3D blue wax model wrapped with the magnetic silica gel component into a 50°C oven to bake and solidify for 0.5 h;

[0103] 6. After solidification, increase the baking temperature to 90°C to melt the blue wax, and open a hole (i.e. a supply hole) at the top of the extension column 2 to make the blue wax flow out;

[0104] 7. Place the device in an ultrasonic oscillator to remove excess impurities;

[0105] 8. Apply a layer of medical polyurethane polymer (material information: Hymedix AI12 AR35 CR104 FR103 FI520) on the surface of the device to improve the biocompatibility of the device and prevent direct contact with the heart to cause infection;

[0106] 9. Uniformly open a plurality of micropores 13 on the inner surfaces of the warp pipe column 11 and the weft pipe column 12, and connect selective filter membranes at the micropores 13: use a laser drilling instrument (such as a laser drilling device of model LHF30PHA of Huagong Laser Company) to form the micropores 13, and the micropores 13 prepared by the above method have a diameter of 0-30 μm. After the micropores 13 are formed, select a therapeutic drug with a diameter smaller than that of the micropores 13 and a magnetic fluid with a diameter larger than that of the micropores 13 according to the pore diameter, so that the therapeutic drug and the magnetic fluid can selectively permeate the micropores.

[0107] Prepare the ventricular assist device with a hollow interior according to the above method, and the material parameters of the obtained device are as follows:

[0108] 1. Physical performance indicators of the material: breaking strength: 2.2±0.3 MPa, compressive strength: 6.55±0.77 MPa, elastic modulus: 78.87±10.39 kPa, and magnetization strength: 61.3 kA / m.

[0109] 2. Biological performance and indicators of the material: cytotoxicity level III; non-adhesive contact time of the material with heart tissue ≥3 months; permeability: 0 within 6 months.

[0110] 3. External coil parameters: provide a magnetic field (other parameters such as magnetic field size, frequency, and coil turns are customized according to patient clinical symptoms).

[0111] 4. The device power pump parameters: the pump can provide constant pressure ≥ 80 mmHg, so that the one-way micro-porous valve "open" to complete the slow release of the intervention drug, but need to be ≤ 200 mmHg, so as not to cause the pipe to be broken due to excessive pressure.

[0112] The working mechanism of the device is as follows:

[0113] The warp pipe column 11 and the weft pipe column 12 are both hollow pipes, the inner wall of the hollow pipe is provided with a micro-porous structure 13, and a one-way selective filter membrane structure is arranged at the micro-porous structure 13, such as the mitral valve between the left atrium and the left ventricle. The hollow pipe can be filled with various therapeutic liquid drugs, and the drug is slowly released on the surface of the heart by external power pump pressure, which can target various intervention drugs to the patient's diseased heart and provide drug synergistic therapy. When the hollow pipe is infused with magnetic fluid, no pressure is applied, so that the magnetic fluid uniformly resides in the hollow pipe without overflowing outside the device body. After the device is magnetically activated, it can be treated by magnetic drive.

[0114] In actual operation, the device is sleeved on the heart of the organism in the same way as in the first application example, and the extension column 2 is fixed in the muscle at the wound to achieve device fixation. The extension column 2 is connected with the external power pump, the pressure environment of the device is consistent with the chest cavity environment in the initial state, there is no pressure difference, the extension column 2 is connected with the external drug infusion equipment, the device is filled with drugs, then the extension column 2 is connected with the external power pump, the device body 1 is infused with pressure by the power pump, the inside of the device body 1 is a positive pressure environment, which forces the selective filter membrane on the inner wall to open, achieving the effect of slow release of the intervention drug. When the device body 1 is infused with magnetic fluid, no pressure is applied to the device, so that the magnetic fluid uniformly resides in the device body 1 without overflowing outside the device body, and the device can be magnetically activated for treatment by magnetic drive. The magnetic drive simultaneously provides power to the heart by active fluid power, achieving multi-method treatment.

[0115] The basic principles, main features and advantages of the present application are shown and described above. However, the above description is only a specific embodiment of the present application, and the technical features of the present application are not limited to this. Any other implementation derived by those skilled in the art without departing from the technical solution of the present application should be covered in the patent scope of the present application.

Claims

1. A ventricular assist device that magnetically drives and assists heartbeats, characterized in that, The ventricular assist device comprises two parts: the main body of the device and the extension column; The main body of the device is made according to cardiac parameters and supports the diseased heart by adhering closely to the surface of the epicardium during operation. An extension column is used to connect the main body of the aforementioned device inside the body to other external attachments. The main body of the device is a heart-shaped mesh structure with its inner diameter decreasing from top to bottom. The bottom surface of the main body is circular. The circumferential surface of the main body is composed of several warp and weft columns interlaced to form a hollow mesh. The ventricular assist device is made by mixing isotropic neodymium iron boron magnetic particles and soft rubber material.

2. The ventricular assist device for magnetically driven assisted cardiac pulsation as described in claim 1, characterized in that, The average diameter of the isotropic NdFeB magnetic particles is 1~5 μm; the soft rubber material is a thermoplastic elastomer, Ecoflex™ 00-10 type soft silicone rubber, or HY-Q series two-component addition-type silicone material; the mass ratio of the isotropic NdFeB magnetic particles to the soft rubber material is 1:

1.

3. The ventricular assist device for magnetically driven assisted cardiac pulsation as described in claim 1, characterized in that, The extension column is located at the large-diameter end of the main body of the device.

4. The ventricular assist device for magnetically driven assisted cardiac pulsation as described in claim 1, characterized in that, The meridian column, the parallel column, and the extension column are all solid structures.

5. The ventricular assist device for magnetically driven assisted cardiac pulsation as described in claim 1, characterized in that, The warp column, the weft column, and the extension column are all hollow structures and are interconnected internally. A supply hole connected to the interior of the extension column is provided at the top of the extension column.

6. The ventricular assist device for magnetically driven assisted cardiac pulsation as described in claim 5, characterized in that, Several micropores are evenly distributed on the inner surfaces of the warp and weft columns, and a selective filter membrane is installed at each micropore.

7. The ventricular assist device for magnetically driven assisted cardiac pulsation as described in claim 6, characterized in that, The diameters of the warp and weft columns are the same, while the diameter of the micropores is less than half the diameter of either the warp or weft column.

8. The ventricular assist device for magnetically driven assisted cardiac pulsation as described in claim 6, characterized in that, The extension column is connected to an external pressure pump system or drug delivery system through its supply port, thereby infusing liquid drugs or magnetic fluid into the meridional and latitudinal columns. When liquid drugs are infused into the meridional and latitudinal columns, the pressure pump system pressurizes the inside of the columns, allowing the drugs inside to be released unidirectionally through a selective filtration membrane to the surface of the heart. When magnetic fluid is infused into the meridional and latitudinal columns, no pressure is applied to the inside of the columns, and the magnetic fluid remains uniformly within the main body of the device without overflowing outside. After the device is magnetically activated, treatment can be performed using magnetic drive.

9. The ventricular assist device for magnetically driven assisted cardiac pulsation as described in claim 1, characterized in that, The outer surface of the ventricular assist device is coated with a biocompatible coating.

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