Ventricular assist device and interventional medical device thereof

Abstract

The invention discloses an interventional medical instrument device which comprises a flexible transmission shaft and a catheter arranged outside the flexible transmission shaft in a sleeving mode, and the catheter comprises an inner catheter layer, a buffer layer and a woven layer; the inner wall of the inner pipe layer defines an inner cavity of the catheter, and the flexible transmission shaft is rotatably arranged in the inner cavity in a penetrating mode; the buffer layer is arranged between the outer wall of the inner pipe layer and the inner wall of the braid layer, and the buffer layer is used for buffering extrusion of the braid layer to the inner pipe layer so as to maintain the inner wall of the inner pipe layer to be in a smooth and flat state. According to the interventional medical instrument device, the smoothness and roundness of the inner wall of the inner pipe layer are improved, so that the flatness and abrasion resistance of the inner surface of the inner pipe layer are kept, and abrasion to the inner pipe layer during rotation of the flexible transmission shaft is reduced. The invention further provides a ventricle assisting device.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly relates to a ventricular assist device and an interventional medical device. Background Art

[0002] Existing known catheter pumps are divided into two categories: one is the motor-integrated type, where the motor connecting shaft directly drives the impeller, and the motor enters the human body together with the catheter; the other is the motor-external type, where the impeller is driven by a flexible transmission shaft, and the motor does not enter the human body together with the catheter and the impeller. The flexible transmission shaft of the external motor type is arranged in the inner cavity of the catheter and is guided and limited by the catheter. To reduce the wear between the flexible transmission shaft and the inner cavity of the catheter, reduce the vibration caused by the high-speed rotation of the flexible transmission shaft, and reduce the heat generated by the wear, physiological fluid is often filled between the flexible shaft and the catheter for lubrication, such as physiological saline or glucose solution.

[0003] Driving the flexible transmission shaft to rotate at high speed in the catheter forms a relatively long kinematic pair. Although the physiological fluid between the two plays a certain degree of lubrication, over time, the inner wall of the catheter will be worn. During the wear process, various-sized particles will be generated. Some of the too-small particles may flow into the body through the bearing clearance, bringing potential biochemical risks. In the prior art, the braided layer in the catheter is closely attached to the outer surface of the inner tube layer, causing wrinkles or braided imprints on the inner surface of the inner tube layer, affecting the roundness and inner wall smoothness of the inner tube layer, increasing the wear on the inner tube layer when driving the flexible transmission shaft to rotate, and generating more particulate matter. Summary of the Invention

[0004] In view of this, the present invention provides an interventional medical device, which improves the inner wall smoothness and roundness of the inner tube layer, keeps the inner surface of the inner tube layer flat and wear-resistant, and reduces the wear on the inner tube layer when the flexible transmission shaft rotates.

[0005] The present invention also provides a ventricular assist device.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An interventional medical device, comprising a flexible transmission shaft and a catheter sleeved outside the flexible transmission shaft, wherein the catheter comprises an inner tube layer, a buffer layer and a braided layer;

[0008] The inner wall of the inner tube layer defines the inner cavity of the catheter, and the flexible transmission shaft is rotatably disposed in the inner cavity;

[0009] The buffer layer is disposed between the outer wall of the inner tube layer and the inner wall of the braided layer, and the buffer layer is used for buffering the extrusion of the braided layer on the inner tube layer to maintain the inner wall of the inner tube layer in a smooth and flat form.

[0010] Optionally, the hardness of the inner tube layer is greater than that of the buffer layer;

[0011] and / or, the wear resistance of the inner tube layer is better than that of the buffer layer.

[0012] Optionally, the thickness of the buffer layer is less than the thickness of either the inner tube layer or the braided layer.

[0013] Optionally, the thickness of the inner tube layer is less than the thickness of the braided layer.

[0014] Optionally, the catheter further includes an outer tube layer, and the thickness of the outer tube layer is greater than the thickness of the braided layer;

[0015] The inner tube layer, the buffer layer, the braided layer and the outer tube layer are relatively fixedly arranged.

[0016] Optionally, the inner tube layer is a thermosetting polyimide, and the buffer layer is a thermoplastic polyether amide.

[0017] Optionally, a support bearing is fixedly arranged inside the inner tube layer, and the inner cavity of the support bearing is used for threading the flexible transmission shaft.

[0018] Optionally, there is one or several support bearings;

[0019] The support bearing is a ceramic bearing.

[0020] Optionally, at least one glue-containing structure is arranged at the position of the inner tube layer for installing the support bearing, and the glue-containing structure is filled with glue for bonding the support bearing.

[0021] Optionally, the glue-containing structure includes a plurality of glue application holes, and the plurality of glue application holes are arranged around the axis of the inner tube layer.

[0022] Optionally, the glue application holes penetrate through the inner tube layer.

[0023] Optionally, the glue-containing structure includes a plurality of glue application seams, and the plurality of glue application seams are arranged around the axis of the inner tube layer.

[0024] Optionally, a glue application area is arranged at the position of the inner tube layer for installing the support bearing, and the support bearing is bonded to the glue application area.

[0025] Optionally, a cutting tube is fixedly arranged inside the inner tube layer, and the support bearing is fixedly arranged inside the cutting tube.

[0026] Optionally, the cutting tube and the support bearing are clamped by a clamping structure.

[0027] Optionally, the snap-fit structure includes a first snap-fit portion and a second snap-fit portion that are cooperatively provided;

[0028] The first snap-fit portion is provided on one of the cutting tube and the support bearing, and the second snap-fit portion is provided on the other. The first snap-fit portion and the second snap-fit portion are provided in one-to-one correspondence.

[0029] Optionally, the cutting tube includes a connection area and a cutting area. The snap-fit structure is provided on the connection area, and the snap-fit structure is connected to the support bearing. Cutting openings are provided on the cutting area.

[0030] Optionally, the catheter further includes an outer tube layer;

[0031] At least one of the buffer layer and the braided layer is provided between the outer tube layer and the inner tube layer. Alternatively, the buffer layer and the braided layer are not provided, and the outer tube layer is directly sleeved on the outer wall of the inner tube layer.

[0032] Optionally, when in use, the catheter includes at least two segments passing through blood vessels with different bending radii. The at least two segments include a first segment and a second segment. The bending radius of the first segment is smaller than that of the second segment, and the corresponding arrangement spacing of the support bearings in the first segment is smaller than the corresponding arrangement spacing of the support bearings in the second segment;

[0033] Optionally, the first segment includes the femoral arch segment of the catheter passing through the femoral arch, and the second segment includes the main arch segment of the catheter passing through the aortic arch.

[0034] Optionally, when in use, the catheter includes at least two segments passing through blood vessels with different bending radii. The at least two segments include a third segment and a fourth segment. The third segment and the fourth segment are adjacent. The bending radius of the third segment is smaller than that of the fourth segment, and the corresponding arrangement spacing of the support bearings in the third segment is greater than or equal to the corresponding arrangement spacing of the support bearings in the fourth segment;

[0035] Optionally, the third segment is the main arch segment of the catheter passing through the aortic arch, and the fourth segment is the sub-arch large bend segment of the catheter passing through the sub-arch large bend of the aortic arch. The corresponding arrangement spacing of the support bearings in the main arch segment is equal to the corresponding arrangement spacing of the support bearings in the sub-arch large bend segment, and the number of bearings arranged in the main arch segment is greater than the number of bearings arranged in the sub-arch large bend segment;

[0036] Optionally, the third section is the main arch section passing through the aortic arch in the catheter, the fourth section is a catheter diameter-changing section located distal to the main arch section, the distal end of the catheter diameter-changing section is connected to the pump head assembly of the interventional medical device, the corresponding arrangement spacing of the support bearings in the main arch section is greater than the corresponding arrangement spacing of the support bearings in the catheter diameter-changing section, and the number of bearings arranged in the main arch section is greater than the number of bearings arranged in the catheter diameter-changing section;

[0037] Preferably, the corresponding arrangement spacing of the support bearings in the catheter diameter-changing section is the smallest; the catheter diameter-changing section is generally in a straight state during use.

[0038] Optionally, the catheter includes a body section that enters the body during use, an external section located outside the body, and a body-external connection section located between the body section and the external section;

[0039] The corresponding arrangement spacing of the support bearings in the body-external connection section is less than the corresponding arrangement spacing of the support bearings in the external section.

[0040] Optionally, the catheter includes at least two sections with different bending states during use, the at least two sections include a fifth section and a sixth section, the fifth section includes some or all of the pipe sections that are generally in a bent state when the catheter is in use, and the sixth section includes some or all of the pipe sections that are generally in a straight state when the catheter is in use;

[0041] The corresponding arrangement spacing of the support bearings in the fifth section is less than the corresponding arrangement spacing of the support bearings in the sixth section.

[0042] Optionally, the catheter includes a catheter diameter-changing section, a main arch section, an inferior aortic arch bend section, a nearly straight section, a femoral arch section, a body-external transition section, and an external section distributed from the distal end to the proximal end, and the support bearings are provided in at least one of the catheter diameter-changing section, the main arch section, the inferior aortic arch bend section, the nearly straight section, the femoral arch section, the body-external transition section, and the external section.

[0043] Optionally, the interventional medical device further includes a rotor shaft, the proximal end of the flexible transmission shaft extends out of the catheter and is fixedly connected to the rotor shaft, and the rotor shaft drives the flexible transmission shaft to rotate;

[0044] There is a gap between the distal end of the rotor shaft and the proximal end of the catheter, and the flexible transmission shaft includes a free section between the distal end of the rotor shaft and the proximal end of the catheter;

[0045] The length of the free section is maintained at a first distance.

[0046] Optionally, the first distance is 3 - 5 mm.

[0047] Optionally, the interventional medical device further includes a coupling assembly. The rotor shaft and the proximal end of the catheter are disposed within the coupling assembly. The coupling assembly has a flushing fluid chamber, and the free section is located within the flushing fluid chamber.

[0048] Optionally, the catheter includes a proximal end portion, an intermediate portion, and a distal end portion. The intermediate portion is disposed between the proximal end portion and the distal end portion. The braided layer is disposed on the intermediate portion. The proximal end of the braided layer is distal to the proximal end portion of the catheter, and the distal end of the braided layer is proximal to the distal end portion of the catheter.

[0049] Optionally, the proximal end portion and the distal end portion of the catheter are the parts where the catheter is cut.

[0050] Optionally, the outer wall of the inner tube layer is subjected to plasma treatment; a buffer layer is disposed on the outer wall of the inner tube layer after plasma treatment, and the braided layer is woven on the outer wall of the buffer layer.

[0051] Optionally, it further includes a film. The catheter includes a first diameter section, a second diameter section, and a third diameter section arranged in sequence.

[0052] The first diameter section is disposed within the film. The second diameter section is disposed proximal to the film, and the second diameter section is continuously arranged with the first diameter section; the third diameter section is disposed proximal to the second diameter section and is continuously arranged with the second diameter section.

[0053] The diameter of the first diameter section is smaller than the diameter of the third diameter section, and the stiffness of the first diameter section is greater than the stiffness of the third diameter section.

[0054] Optionally, the stiffness of the second diameter section is greater than the stiffness of the third diameter section and less than the stiffness of the first diameter section.

[0055] Optionally, the second diameter section is frustum-shaped, and the diameter of the second diameter section gradually decreases from the proximal end to the distal end.

[0056] Optionally, the interventional medical device is an interventional blood pump. The interventional blood pump further includes a pump head assembly, and the pump head assembly is connected to the distal end of the catheter; the pump head assembly includes an impeller, and the impeller is connected to the distal end of the flexible transmission shaft.

[0057] In the use state, the interventional medical device is percutaneously inserted into the body of the target object. The pump head assembly is located within the heart, and the flexible transmission shaft conducts power to the impeller to drive the impeller to rotate.

[0058] As can be seen from the above technical solution, the interventional medical device provided by the present invention includes a flexible transmission shaft and a catheter sleeved outside the flexible transmission shaft. By providing a buffer layer between the inner tube layer and the braided layer of the catheter, the braided layer is isolated from the inner tube layer. The braided layer is braided on the buffer layer instead of on the inner tube layer, avoiding the force during the braiding process of the braided layer directly acting on the inner tube layer to form protrusions, and also avoiding the braiding marks of the braided layer affecting the roundness and smoothness of the inner wall of the inner tube layer. The probability of the inner wall of the inner tube layer having wrinkles due to the influence of the braided layer is reduced, the smoothness and roundness of the inner wall of the inner tube layer are improved, the inner tube layer maintains the flat wear resistance of its inner surface, the wear of the inner tube layer caused by the rotation of the flexible transmission shaft is reduced, the number of particulate matters is greatly reduced, the risk of particulate matters entering the cardiovascular system is reduced, and the safety of the interventional medical device is improved.

[0059] The present invention also provides a ventricular assist device, including a driving component and the above-mentioned interventional medical device;

[0060] In the use state, the driving component is located outside the body, at least part of the interventional medical device is inserted into the body through the catheter, and the driving component drives the flexible transmission shaft to rotate in the catheter.

[0061] The ventricular assist device of the present invention includes the above-mentioned interventional medical device, and therefore has the advantages of the above-mentioned interventional medical device, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0063] Figure 1 It is a schematic structural diagram of the catheter of the interventional medical device provided by the embodiment of the present invention;

[0064] Figure 2 It is a schematic cross-sectional structural diagram of the catheter of the interventional medical device provided by the embodiment of the present invention;

[0065] Figure 3 For Figure 2 It is a partial enlarged structural diagram of part A in

[0066] Figure 4 For Figure 2 It is a partial enlarged structural diagram of part B in

[0067] Figure 5 ForFigure 2 Schematic cross-sectional structure diagram at the C-C position in

[0068] Figure 6 Schematic structure diagram of the support bearing of the interventional medical device provided by an embodiment of the present invention arranged in the catheter;

[0069] Figure 7 is Figure 6 Schematic cross-sectional structure diagram at the D-D position in

[0070] Figure 8 Schematic structure diagram of the support bearing of the interventional medical device provided by another embodiment of the present invention arranged in the catheter;

[0071] Figure 9 is Figure 8 Schematic cross-sectional structure diagram at the E-E position in

[0072] Figure 10 Schematic cross-sectional structure diagram of the catheter provided by an embodiment of the present invention;

[0073] Figure 11 Schematic cross-sectional structure diagram of the catheter provided by another embodiment of the present invention;

[0074] Figure 12 Schematic cross-sectional structure diagram of the catheter provided by yet another embodiment of the present invention;

[0075] Figure 13 Schematic structure diagram of the cutting tube provided by an embodiment of the present invention;

[0076] Figure 14 is Figure 13 Schematic cross-sectional structure diagram after a support bearing is arranged in the cutting tube in

[0077] Figure 15 Schematic structure diagram of the support bearing arranged in the cutting tube provided by an embodiment of the present invention;

[0078] Figure 16 Schematic structure diagram of the support bearing provided by an embodiment of the present invention;

[0079] Figure 17 Schematic structure diagram of the catheter inserted into a blood vessel provided by an embodiment of the present invention;

[0080] Figure 18 Schematic sectional structure diagram of the catheter provided by an embodiment of the present invention;

[0081] Figure 19 Schematic structure diagram of the catheter and the rotor shaft coaxially arranged provided by an embodiment of the present invention;

[0082] Figure 20Schematic diagram of the setting structure of the coupling component and the driving component provided by the embodiment of the present invention;

[0083] Figure 21 Schematic diagram of the structure where the coaxiality of the catheter and the rotor shaft provided by the embodiment of the present invention is within a suitable range;

[0084] Figure 22 Schematic diagram of the structure where the coaxiality of the catheter and the rotor shaft provided by the embodiment of the present invention exceeds the suitable range;

[0085] Figure 23 Schematic diagram of the fluoroscopic structure of the film covering position of the interventional medical device provided by the embodiment of the present invention;

[0086] Figure 24 Schematic diagram of the sectional structure of the film covering position of the interventional medical device provided by the embodiment of the present invention.

[0087] Wherein:

[0088] 021, first diameter section, 022, second diameter section, 023, third diameter section, 024, distal end, 025, proximal end,

[0089] 1, flexible transmission shaft, 2, catheter, 201, developing ring, 202, inner tube layer, 2021, glue application hole, 2022, glue application seam, 203, buffer layer, 204, braided layer, 205, outer tube layer, 3, support bearing, 301, card slot, 4, cutting tube, 401, buckle, 402, connection area, 403, cutting area, 4031, cutting opening, 5, blood vessel, 6, heart, 7, rotor shaft, 8, outer rotor, 9, motor, 10, free section, 11, coupling component, 12, driving component, 13, film covering, 1301, proximal outlet, 1302, proximal film covering connection section, 1303, distal inlet, 14, stent, 15, first connection sleeve, 16, second connection sleeve, 17, flexible protection end, 18, flushing liquid cavity. Detailed implementation manners

[0090] The present invention discloses an interventional medical device, which improves the inner wall smoothness and roundness of the inner tube layer, keeps the inner surface of the inner tube layer flat and wear-resistant, and reduces the wear of the inner tube layer when the flexible transmission shaft rotates.

[0091] The present invention also discloses a ventricular assist device.

[0092] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0093] Referring to Figures 1 to 5 , the interventional medical device of the present invention includes a flexible drive shaft 1 and a catheter 2 sleeved outside the flexible drive shaft 1. The catheter 2 includes an inner tube layer 202, a buffer layer 203, and a braided layer 204. The inner wall of the inner tube layer 202 defines the inner cavity of the catheter 2, and the flexible drive shaft 1 is rotatably disposed in the inner cavity. The buffer layer 203 is disposed between the outer wall of the inner tube layer 202 and the inner wall of the braided layer 204. The buffer layer 203 is used to buffer the extrusion of the braided layer 204 on the inner tube layer 202 to maintain the inner wall of the inner tube layer 202 in a smooth and flat state.

[0094] The interventional medical device of the present invention includes a flexible drive shaft 1 and a catheter 2 sleeved outside the flexible drive shaft 1. By providing a buffer layer 203 between the inner tube layer 202 and the braided layer 204 of the catheter 2, the braided layer 204 is separated from the inner tube layer 202. The braided layer 204 is braided on the buffer layer 203 instead of on the inner tube layer 202, avoiding the force in the braiding process of the braided layer 204 directly acting on the inner tube layer 202 to form protrusions, and also avoiding the braiding marks of the braided layer 204 affecting the roundness and smoothness of the inner wall of the inner tube layer 202, reducing the probability of wrinkles on the inner wall of the inner tube layer 202 due to the influence of the braided layer 204, improving the smoothness and roundness of the inner wall of the inner tube layer 202, keeping the inner surface of the inner tube layer 202 flat and wear-resistant, reducing the wear of the inner tube layer 202 when the flexible drive shaft 1 rotates, greatly reducing the number of particulate matters, reducing the risk of particulate matters entering the cardiovascular system, and enhancing the safety of the interventional medical device.

[0095] To improve the wear resistance of the inner tube layer 202, the hardness of the inner tube layer 202 is greater than the hardness of the buffer layer 203; further, the wear resistance of the inner tube layer 202 is also greater than the wear resistance of the buffer layer 203, thereby reducing the number of particulate matters generated by the wear of the inner tube layer 202 during the use of the catheter 2. Optionally, the inner tube layer 202 has the greatest wear resistance and the greatest hardness.

[0096] To reduce the influence of the buffer layer 203 on the bending passability of the catheter 2 and the catheter diameter, the thickness of the buffer layer 203 is less than the thickness of either the inner tube layer 202 or the braided layer 204. Optionally, the buffer layer 203 has the smallest thickness.

[0097] To improve the wear resistance of the inner tube layer 202, the inner tube layer 202 has a relatively high hardness. However, when the inner tube layer 202 is used inside the human body, it needs to be bent, so the thickness of the inner tube layer 202 is relatively thin. Specifically, the thickness of the inner tube layer 202 is less than the thickness of the braided layer 204. Optionally, the buffer layer 203 has the smallest thickness, and the thickness of the inner tube layer 202 is only second to that of the buffer layer.

[0098] To improve the surface smoothness of the catheter 2 and enhance the comfort and smoothness during the intervention of the catheter 2, the catheter 2 further includes an outer tube layer 205. The thickness of the outer tube layer 205 is greater than the thickness of the braided layer 204 to improve the durability of the catheter 2. Preferably, the buffer layer 203 has the smallest thickness, the thickness of the inner tube layer 202 is greater than the thickness of the buffer layer 203, the thickness of the braided layer 204 is greater than the thickness of the inner tube layer 202, and the outer tube layer 205 has the largest thickness. The braided layer 204 and the outer tube layer 205 maintain the stiffness of the catheter 2.

[0099] For the catheter 2 of the present invention, the inner tube layer 202 is made of a material with high hardness and good wear resistance, thereby reducing the wear of the inner wall of the inner tube layer 202 caused by the friction and collision between the flexible transmission shaft 1 and the inner tube layer 202 when the flexible transmission shaft 1 works inside the inner tube layer 202, and reducing the number of particles generated due to wear. To avoid the thickness of the inner tube layer 202 affecting the bending of the catheter 2, the thickness of the inner tube layer 202 is relatively thin, improving the flexibility of the catheter 2 during bending.

[0100] To prevent relative displacement between the inner tube layer 202, the buffer layer 203, the braided layer 204, and the outer tube layer 205 of the catheter 2, improve the structural stability of the catheter 2, and enhance the reliability during intervention, the inner tube layer 202, the buffer layer 203, the braided layer 204, and the outer tube layer 205 are relatively fixedly arranged. Specifically, the inner tube layer 202, the buffer layer 203, the braided layer 204, and the outer tube layer 205 are bonded together.

[0101] Optionally, the inner tube layer 202 is a polyimide (PI) layer. Optionally, the inner tube layer 202 is a thermosetting polyimide (PI) layer. The thermosetting material has a greater tensile strength, higher hardness, and better wear resistance. These advantages help to reduce wear and can meet the requirements of the inner tube layer 202. The buffer layer 203 is a thermoplastic polyether amide (pebax) layer. Polyimide is a high-performance engineering plastic with excellent thermal stability, good mechanical properties, good chemical resistance and solvent resistance, good flexibility, high temperature resistance, and lightweight characteristics. The thermoplastic polyether amide has good wear resistance and processing performance. The outer tube layer 205 can also be selected as a thermoplastic polyether amide (pebax) layer.

[0102] To achieve a better connection with the buffer layer 203, the outer wall of the inner tube layer 202 is subjected to plasma treatment. The buffer layer 203 is disposed on the outer wall of the inner tube layer 202 after plasma treatment, and the braided layer 204 is braided on the outer wall of the buffer layer 203. The inner tube layer 202 is produced using a coating process, and the surface of the inner tube layer 202 is subjected to plasma treatment to have a better connection with the buffer layer 203, which helps to reduce wear and thus reduce particle generation.

[0103] In summary, for the catheter 2 with the braided layer 204, if the braided layer 204 is in close contact with the inner tube layer 202 (PI layer), it may cause adverse effects on the inner wall of the inner tube layer 202 (PI layer), such as causing the inner wall of the inner tube layer 202 to be non-circular or having braiding marks on the inner wall. Adding a buffer layer 203 made of pebax material between the braided layer 204 and the inner tube layer 202 can play a role in isolating the adverse effects. If the braided layer 204 moves outward, it will help to reduce wear and thus reduce particle generation. The reason is that during the braiding process of the braided layer 204, a force acts on the inner tube layer 202 (PI layer), which may cause deformation of the relatively thin inner tube layer 202 (PI layer), resulting in defects such as protrusions on the inner wall of the inner tube layer 202. The PI material is a material with a low coefficient of friction and high wear resistance. Therefore, when the braided layer 204 moves outward, the buffer layer 203 (pebax layer) between the braided layer 204 and the inner tube layer 202 (PI layer) can prevent deformation of the PI layer during the braiding process, so that the PI layer maintains its smooth and wear-resistant surface. Moreover, the PI material is very hard, and when it is thick, it will affect bending during use. Therefore, it is not appropriate to solve the technical problem by thickening the inner tube layer 202 (PI layer). It is more suitable to set a buffer layer 203 made of pebax material between the PI layer and the metal braided layer.

[0104] In one embodiment, in order to reduce the frictional force when the flexible transmission shaft 1 rotates in the inner cavity of the catheter 2, a support bearing 3 is fixedly arranged in the inner tube layer 202, as Figures 6 to 9 shown. The inner cavity of the support bearing 3 is used for passing through the flexible transmission shaft 1, and the inner cavity surface of the support bearing 3 is used for supporting the flexible transmission shaft 1, reducing the probability of the flexible transmission shaft 1 coming into direct contact with the inner tube layer 202 and generating sliding friction. Since under the same usage conditions, the coefficient of friction of rolling friction is less than that of sliding friction, therefore, by setting the support bearing 3 to support the flexible transmission shaft 1, it can not only reduce the particles generated by the friction between the inner tube layer 202 and the flexible transmission shaft 1, but also improve the smoothness of the rotation of the flexible transmission shaft 1, which is beneficial to the reliable transmission of the driving force.

[0105] Among them, one or several support bearings 3 are provided. Preferably, several support bearings 3 are provided, and several here means two or more. When multiple support bearings 3 are provided, the multiple support bearings 3 are arranged at intervals along the extension path of the flexible transmission shaft 1, so as to realize reliable support for the flexible transmission shaft 1. The support bearing 3 is made of ceramic material or metal material, and the flexible transmission shaft 1 is made of metal material or polymer material.

[0106] Furthermore, the support bearing 3 is preferably a ceramic bearing, which changes the friction between metal and metal to the friction between metal and ceramic, further reducing the number of particles.

[0107] In order to prevent the installation position of the support bearing 3 in the conduit 2 from changing and deviating from the set position, it is necessary to limit the support bearing 3. In one embodiment, at least one glue-containing structure is provided at the position of the inner tube layer 202 for installing the support bearing 3, and the glue-containing structure is filled with glue for bonding the support bearing 3, and the position of the support bearing 3 is fixed to the inner surface of the inner tube layer 202 through the glue, so as to prevent the position of the support bearing 3 from moving.

[0108] In one embodiment, the glue-containing structure includes several glue application holes 2021, and the multiple glue application holes 2021 are arranged around the axis of the inner tube layer 202. Specifically, as Figure 6 and Figure 7 shown, four glue application holes 2021 are correspondingly provided for each support bearing 3, and the four glue application holes 2021 are evenly distributed along the circumferential direction of the inner tube layer 202. In order to facilitate the processing of the glue application holes 2021 and improve the bonding firmness, the glue application holes 2021 penetrate through the inner tube layer 202.

[0109] In another embodiment, as Figure 8 and Figure 9 shown, the glue-containing structure includes several glue application seams 2022, and the multiple glue application seams 2022 are arranged around the axis of the inner tube layer 202. Specifically, four glue application seams 2022 are correspondingly provided for each support bearing 3, and the four glue application seams 2022 are evenly distributed along the circumferential direction of the inner tube layer 202. In order to facilitate the processing of the glue application seams 2022 and improve the bonding firmness, the glue application seams 2022 penetrate through the inner tube layer 202.

[0110] Optionally, a glue application area is provided at the position of the inner tube layer 202 for installing the support bearing 3, and the support bearing 3 is directly bonded to the glue application area. The glue application area can be a glue application groove.

[0111] In the above two embodiments, the structure of the conduit 2 including four layers of the inner tube layer 202, the buffer layer 203, the braided layer 204 and the outer tube layer 205 is taken as an example to illustrate the conduit structure after adding the support bearing 3 in the conduit 2. However, it should be noted that after adding the support bearing 3 in the conduit 2, the structure of the conduit 2 is not limited to the above-mentioned four-layer structure, and can also be other structures.

[0112] When a support bearing 3 is arranged inside the conduit 2, an outer tube layer 205 can also be arranged on the outer surface of the conduit 2. At least one of the above-mentioned buffer layer 203 and braided layer 204 is arranged between the outer tube layer 205 and the inner tube layer 202, or, the buffer layer 203 and the braided layer 204 are cancelled, and the outer tube layer 205 is directly sleeved on the outer wall of the inner tube layer 202.

[0113] The outer tube layer 205 can be wrapped on the outer surface of the braided layer 204. The flexible transmission shaft 1 passes through the inner cavity of the support bearing 3, reducing the probability of direct contact between the flexible transmission shaft 1 and the inner wall of the conduit 2. Thus, the wear between the flexible transmission shaft 1 and the inner wall of the conduit 2 is reduced. Therefore, the braided layer 204 may not be arranged on the outer side of the inner tube layer 202, or the buffer layer 203 may not be arranged, or the outer tube layer 205 is directly arranged on the outer side of the inner tube layer 202.

[0114] For example, in another embodiment, as Figure 10 shown, it is the case where the conduit 2 includes three layers, namely an inner tube layer 202, a buffer layer 203 and an outer tube layer 205, and the buffer layer 203 is arranged between the inner tube layer 202 and the outer tube layer 205. Or, as Figure 11 shown, it is the case where the conduit 2 includes three layers, namely an inner tube layer 202, a braided layer 204 and an outer tube layer 205, and the braided layer 204 is arranged between the inner tube layer 202 and the outer tube layer 205. Or, as Figure 12 shown, it is the case where the conduit 2 includes two layers, namely an inner tube layer 202 and an outer tube layer 205.

[0115] In a specific embodiment, a cutting tube 4 is fixedly arranged inside the inner tube layer 202. As Figure 13 and Figure 14 shown, a support bearing 3 is fixedly arranged inside the cutting tube 4, and the flexible transmission shaft 1 passes through the support bearing 3. In this embodiment, in order to facilitate the limitation of the support bearing 3, the cutting tube 4 and the support bearing 3 are clamped through a clamping structure. The cutting tube 4 made of metal can replace the braided layer 204, providing a certain rigidity to the conduit 2, and can be bent, and is also convenient for the installation of the support bearing 3. Thus, the braided layer 204 may not be arranged on the outer side of the inner tube layer 202, and correspondingly, the buffer layer 203 may not be arranged either. The outer tube layer 205 can be directly arranged on the outer side of the inner tube layer 202, simplifying the structure of the conduit 2, as Figure 15 shown.

[0116] Furthermore, the clamping structure includes a first clamping part and a second clamping part which are cooperatively arranged. One of the cutting tube 4 and the support bearing 3 is provided with the first clamping part, and the other is provided with the second clamping part, and the first clamping part and the second clamping part are arranged in one-to-one correspondence. In one embodiment, as Figure 13 and Figure 14As shown, a first clamping portion is provided on the cutting tube 4, and the first clamping portion is a buckle 401. A second clamping portion is provided on the support bearing 3, and the second clamping portion is a clamping groove 301. The buckle 401 is clamped in the clamping groove 301. To ensure the position reliability of the support bearing 3, at least one clamping groove 301 is provided at each end of each support bearing 3, as Figure 16 shown, which is a structural diagram of providing one clamping groove 301 at each end of the support bearing 3.

[0117] Among them, the cutting tube 4 includes a connection area 402 and a cutting area 403. A clamping structure is provided on the wall surface of the metal cylinder of the connection area 402, and the clamping structure is connected to the support bearing 3. A cutting opening 4031 is provided on the cutting area 403, as Figure 13 shown, and the cutting opening 4031 facilitates the bending of the catheter.

[0118] When the catheter 2 is in use, it includes at least two segments passing through blood vessels 5 with different bending radii. The at least two segments include a first segment and a second segment. The bending radius of the first segment is smaller than that of the second segment, and the corresponding arrangement spacing of the support bearings 3 in the first segment is smaller than the corresponding arrangement spacing of the support bearings 3 in the second segment, so as to prevent the flexible transmission shaft 1 from abutting against the inner wall of the catheter 2 when bending at a position with a small bending radius. Optionally, the first segment includes the femoral arch segment of the catheter 2 passing through the femoral arch, and the femoral arch segment is Figure 17 and Figure 18 the A5-A6 segment of the catheter 2 in Figure 17 and Figure 18 the A2-A3 segment of the catheter 2 in

[0119] In another embodiment, when the catheter 2 is in use, it includes at least two segments passing through blood vessels 5 with different bending radii. The at least two segments include a third segment and a fourth segment. The third segment and the fourth segment are adjacent. The bending radius of the third segment is smaller than that of the fourth segment, and the corresponding arrangement spacing of the support bearings 3 in the third segment is greater than or equal to the corresponding arrangement spacing of the support bearings 3 in the fourth segment. For the catheter segment (the above-mentioned fourth segment) adjacent to the part with a smaller bending radius (the above-mentioned third segment) in the catheter, the arrangement spacing of the support bearings 3 in this part of the catheter segment can also be the same as that of the part with a smaller bending radius, or slightly smaller than the arrangement spacing of the support bearings 3 in the catheter segment with a smaller bending radius, so as to adapt to patients with different body types. If the third segment is not accurately located in the blood vessel with a small bending radius after intervention, but at least part of the adjacent fourth segment is located in the blood vessel with a small bending radius, then the arrangement spacing of the support bearings 3 in the adjacent fourth segment can also prevent the flexible transmission shaft 1 from abutting against the inner wall of the catheter 2.

[0120] In one case, the third segment is the main arch segment of the catheter 2 passing through the aortic arch, and the main arch segment is Figure 17 andFigure 18 The segment A2 - A3 of the catheter 2 in

[0121] In addition, the place where the blood vessel bending radius is small may be the aortic arch. If the third segment is the main arch segment passing through the aortic arch, then the distal catheter segment will basically be further inserted into the heart 6. Adjusting the arrangement spacing of the support bearings 3 smaller or keeping it consistent with the main arch segment in the part close to the heart 6 is beneficial to improving the rotational stability of the flexible transmission shaft 1, and further enhancing the pumping stability and blood compatibility of the pump head assembly. Specifically, in another case, the third segment is the main arch segment of the catheter 2 passing through the aortic arch, and the main arch segment is Figure 17 and Figure 18 the segment A2 - A3 of the catheter 2 in Figure 17 and Figure 18 The fourth segment is the catheter diameter - changing segment located distally to the main arch segment, and the catheter diameter - changing segment is

[0122] the segment A1 - A2 of the catheter 2 in

[0123] Among them, the catheter 2 includes an in - vivo segment that is inserted into the body during use, an in - vitro segment located outside the body, and an in - vivo and in - vitro connection segment. The in - vivo and in - vitro connection segment is located between the in - vivo segment and the in - vitro segment. As shown in Figure 17 and Figure 18 , the in - vivo and in - vitro connection segment is the segment A6 - A7 of the catheter 2 in the figure, and the in - vitro segment is the segment A7 - A8 of the catheter 2 in the figure. The arrangement spacing of the support bearings 3 corresponding to the in - vivo and in - vitro connection segment is smaller than that of the support bearings corresponding to the in - vitro segment. A part of the in - vivo and in - vitro connection segment is inside the body and a part is outside the body, and it is easy to have a curved path between the two. For example, the intervention position and the driving motor are eccentrically placed, or touching the catheter 2 during use may cause the in - vivo and in - vitro connection segment to bend. Therefore, setting the support bearings 3 with a smaller arrangement spacing in the in - vivo and in - vitro connection segment can further reduce the probability of the flexible transmission shaft 1 rubbing against the inner wall of the catheter 2.

[0124] In another embodiment, the catheter 2 includes at least two sections with different bending states when in use, and the at least two sections include a fifth section and a sixth section. The fifth section includes part or all of the section of the catheter 2 that is approximately bent when in use, and the sixth section includes part or all of the section of the catheter 2 that is approximately straight when in use. The corresponding arrangement spacing of the support bearings 3 in the fifth section is smaller than the corresponding arrangement spacing of the support bearings 3 in the sixth section. In this embodiment, the sixth section is Figure 17 and Figure 18 The fifth section is the catheter 2's near-straight section A4-A5 or extracorporeal section A7-A8. The fifth section is the catheter's variable diameter section A1-A2, main arch section A2-A3, sub-arch large bend section A3-A4, femoral arch section A5-A6, or intracorporeal connecting section A6-A7. By providing support bearings 3 at a smaller spacing in the fifth section, the probability of the flexible transmission shaft 1 rubbing against the inner wall of the catheter 2 can be further reduced, reducing wear between the inner wall of the catheter 2 and the flexible transmission shaft 1 in the bent position, reducing local stress concentration on the flexible transmission shaft 1 passing through the catheter 2, and facilitating rotation of the flexible transmission shaft 1.

[0125] Specifically, such as Figure 17 、 Figure 18 As shown, the catheter 2 includes a catheter diameter-reducing section A1-A2, a main arch section A2-A3, a sub-arch large curvature section A3-A4, a near straight section A4-A5, a femoral arch section A5-A6, an intracorporeal transition section A6-A7, and an extracorporeal section A7-A8, which are distributed from the distal end to the proximal end. A support bearing 3 is provided in at least one of the catheter diameter-reducing section A1-A2, the main arch section A2-A3, the sub-arch large curvature section A3-A4, the near straight section A4-A5, the femoral arch section A5-A6, the intracorporeal transition section A6-A7, and the extracorporeal section A7-A8. In a specific embodiment, referring to Figure 17, the variable diameter section A1 - A2 of the catheter is approximately a straight section. The arrangement spacing of the support bearings 3 in this section can be 18 mm, and the number of bearings arranged is 3. The bending radius of the main bow section A2 - A3 is approximately 30 - 50 mm. The arrangement spacing of the support bearings 3 in this section can be 26 mm, and the number of bearings arranged can be 7. The bending radius of the large under - bow section A3 - A4 is approximately 90 - 110 mm. The arrangement spacing of the support bearings 3 in this section can be 26 mm, and the number of bearings arranged can be 3. The near - straight section A4 - A5 is approximately a straight section. The arrangement spacing of the support bearings 3 in this section can be 100 mm, and the number of bearings arranged can be 4. The bending radius of the femoral - bow section A5 - A6 is approximately 30 - 50 mm. The arrangement spacing of the support bearings 3 in this section can be 25 mm, and the number of bearings arranged can be 2. The bending radius of the in - vivo and in - vitro transition section A6 - A7 is approximately 60 - 80 mm. The arrangement spacing of the support bearings 3 in this section can be 25 mm, and the number of bearings arranged can be 4. The in - vitro section A7 - A8 is approximately a straight section. The arrangement spacing of the support bearings 3 in this section can be 100 mm, and the number of bearings arranged can be 4. It should be noted that the above data are all for illustrative purposes. The present application does not specifically limit the division of different sections of the catheter and the specific bearing setting methods of different sections. Those skilled in the art can set according to specific interventional medical device devices.

[0126] In order to provide driving force for the impeller in the pump head assembly, the interventional medical device device further includes a rotor shaft 7. The rotor shaft 7 is located inside the cylinder of the outer rotor 8 driven by the motor 9 during use. The proximal end of the flexible transmission shaft 1 extends out of the catheter 2 and is fixedly connected to the rotor shaft 7. As Figure 19 and Figure 20 shown, the outer rotor 8 drives the inner rotor to rotate magnetically. The rotor shaft 7 inside the inner rotor drives the flexible transmission shaft 1 to rotate, and the distal end of the flexible transmission shaft 1 drives the impeller of the pump head assembly to rotate. It can be understood that the distal end of the rotor shaft 7 is connected to the proximal end of the flexible transmission shaft 1. The above - mentioned proximal end refers to the end that is close to the operating medical staff and far from the patient's heart 6 in the use state. The above - mentioned distal end refers to the end that is far from the operating medical staff and close to the patient's heart 6 in the use state. Among them, the rotor shaft 7 is a rigid shaft.

[0127] In order to prevent the distal end of the rigid rotor shaft 7 from colliding with the proximal end of the catheter 2 during rotation, there is a gap between the distal end of the rotor shaft 7 and the proximal end of the catheter 2, that is, the flexible transmission shaft 1 includes a free section 10 between the distal end of the rotor shaft 7 and the proximal end of the catheter 2, as Figure 19 shown by the shaded part in. The length of the free section 10 is maintained at a first distance.

[0128] In one embodiment, the range of the first distance is 3 - 5 mm. When the length of the free section 10 is too small, the distal end of the rotor shaft 7 is likely to collide with the proximal end of the catheter 2 during rotation; and when this length is small, when there is a deviation in the coaxiality between the rotor shaft 7 and the catheter 2, the position of the flexible transmission shaft 1 near the proximal end will approach the inner wall of the catheter 2, as Figure 21 shown. When the deviation in the coaxiality between the rotor shaft 7 and the catheter 2 is relatively large, the position of the flexible transmission shaft 1 near the proximal end of the free section 10 will contact the inner wall of the catheter 2, resulting in an unacceptable wear due to an excessive contact force between the flexible transmission shaft 1 and the wall of the catheter 2, as Figure 22 shown. If the length of the flexible transmission shaft 1 extending out is too long, when the flexible transmission shaft 1 rotates, large vibrations will occur due to insufficient restraint.

[0129] The above interventional medical device is connected to drive the rotor through the flexible transmission shaft 1. The flexible transmission shaft 1 transfers the torque from the rotor to the pump head under the support of the catheter 2. When rotating at a high speed, the flexible transmission shaft 1 may be subject to the following axial forces: the impeller hydraulically pulls the transmission system; the force generated by the magnetic coupling (axially pulling the internal and external components into a straight line); the force generated by the shape change during the operation of the device (the length changes of the catheter 2 and the transmission system are different after bending); the tensile or compressive force of the flexible shaft caused by the assembly of the flexible transmission shaft 1; the force generated by the spiral structure of the flexible transmission shaft 1 operating in the flushing fluid. The spiral structure pushes the fluid forward, so a force of equal magnitude and opposite direction is generated; the component of the frictional force between the self-rotation of the spiral structure of the flexible transmission shaft 1 and the inner wall of the catheter 2. Therefore, to ensure the smooth operation of the flexible transmission shaft 1, some axial degrees of freedom are required to release the displacement caused by the above axial forces, otherwise unacceptable wear will occur due to an excessive contact force between the flexible transmission shaft 1 and the catheter 2.

[0130] To ensure the degrees of freedom required for the rotation of the flexible transmission shaft 1, the following dimensions are controlled to achieve this: at the proximal inlet of the catheter 2, the coaxiality between the rotor shaft 7 and the catheter 2; and outside the proximal inlet of the catheter 2, the length of the free section 10 that the flexible transmission shaft 1 extends out. An excessive eccentricity between the rotor shaft 7 and the catheter 2 will cause the flexible transmission shaft 1 to contact the catheter 2. Outside the proximal inlet of the catheter 2, for the length of the free section 10 that the flexible transmission shaft 1 extends out, if the free section 10 is too long, the movement of the unsupported flexible transmission shaft 1 will be difficult to control, and if it is too short, a large contact force will be caused. With a certain displacement, the longer the length of the free section 10, the smaller the contact force; if it is too long, large vibrations will occur when the flexible transmission shaft 1 rotates due to insufficient restraint. Figure 21 and Figure 22 are two cases of eccentric settings for the rotor shaft 7 and the catheter 2, Figure 21 is the case with a relatively small eccentricity between the two, Figure 22This is the case of a relatively large eccentricity. In one embodiment, when the length of the free section 10 of the flexible transmission shaft 1 is 3 mm, a displacement of 0.3 mm will generate a radial force of 1 N, which is 3.33 N / mm. When the length of the free section 10 of the flexible transmission shaft 1 is 5 mm, a displacement of 0.3 mm will generate a radial force of 0.4 N, which is 1.33 N / mm.

[0131] In summary, a reasonable free section 10 is provided on the flexible transmission shaft 1, and the coaxiality of the rotor shaft 7 and the catheter 2 is limited to reduce excessive local wear of the flexible transmission shaft 1 caused by non - concentricity, and to reduce the limitation of the axial degree of freedom of the flexible transmission shaft 1 caused by the radial force during operation, thereby achieving the purpose of reducing excessive wear at the bending position. By controlling the assembly accuracy of the flexible transmission shaft 1 and optimizing the force - bearing form during operation, its operating resistance is reduced, thereby reducing wear and the amount of particulate matter released. By controlling the assembly accuracy of the drive shaft and optimizing the force - bearing form during operation, its operating resistance is reduced, thereby reducing wear and the amount of particulate matter released.

[0132] Furthermore, the interventional medical device further includes a coupling assembly 11. The proximal ends of the rotor shaft 7 and the catheter 2 are disposed within the coupling assembly 11. The coupling assembly 11 has a flushing fluid cavity 18, as Figure 20 shown. The free section 10 is located within the flushing fluid cavity 18. The flushing fluid within the flushing fluid cavity 18 is used to flush the catheter 2.

[0133] To facilitate cutting the catheter 2 and maintaining the smoothness of the inner walls at both ends of the catheter 2, the catheter 2 includes a proximal end portion 025, an intermediate portion, and a distal end portion 024, as Figure 1 、 Figure 3 and Figure 4 shown. The intermediate portion is disposed between the proximal end portion 025 and the distal end portion 024. A braided layer 204 is disposed on the intermediate portion. The proximal end of the braided layer 204 is located on the far side of the proximal end portion 025 of the catheter 2. The length of the proximal end portion 025 is L2, as Figure 4 shown. The distal end of the braided layer 204 is located on the near side of the distal end portion 024 of the catheter 2. The length of the distal end portion 024 is L1, as Figure 3 shown. That is, the proximal end portion 025 and the distal end portion 024 of the catheter 2 do not have the braided layer 204. Since the proximal end portion 025 and the distal end portion 024 of the catheter 2 are the parts for cutting the catheter 2, without the braided layer 204, the shearing force during catheter 2 cutting can be reduced, facilitating cutting the catheter 2, ensuring the neatness of the cutting position of the catheter 2, thereby reducing the generation of particulate matter, and at the same time facilitating the connection of the ends of the catheter 2. Among them, the distal end of the catheter 2 is connected to the bracket 14 of the pump head assembly, as Figure 23 and 24As shown, specifically, the distal end of the catheter 2 is connected to the proximal end of the stent 14 through the first connecting sleeve 15, that is, the thinnest section at the distal end of the catheter 2 and the stent 14 are tightly sleeved and connected through the first connecting sleeve 15. The stent 14 is arranged inside the film 13. An impeller is arranged inside the stent 14. The rotating impeller is arranged inside the stent 14. The stent 14 supports the film 13 and provides space for the rotation of the impeller. The distal end of the flexible transmission shaft 1 is connected to the impeller shaft of the impeller, and the proximal end of the flexible transmission shaft 1 is connected to the rotor shaft 7. The lengths L2 of the proximal end portion 025 and L1 of the distal end portion 024 are preset by those skilled in the art according to actual needs. The stent 14 is a cavity structure with mesh holes on the wall surface.

[0134] Further, as Figure 24 shown, the interventional medical device of the present invention includes a film 13. The distal part of the catheter 2 includes a first diameter section 021, a second diameter section 022, and a third diameter section 023 arranged in sequence. As Figure 1 shown, the second diameter section 022 is a variable diameter section. The film 13 includes a proximal connecting section 1302 of the film and a distal connecting section of the film. The proximal connecting section 1302 of the film is connected to the second diameter section 022. The first diameter section 021 is arranged inside the film 13. The distal connecting section of the film is tightly sleeved and fixed on the distal end of the stent 14 by the second connecting sleeve 16, or the distal connecting section of the film is tightly sleeved and fixed on the outer periphery of the flexible protection end 17 by the second connecting sleeve 16. The flexible protection end 17 is arranged at the distal end of the stent 14 to avoid scratching the inner wall of the blood vessel. A distal inlet 1303 is arranged at a position near the distal end of the film 13, and a proximal outlet 1301 is arranged at a position near the proximal end. When the impeller rotates, blood enters the inner cavity of the film 13 from the distal inlet 1303, then passes through the mesh holes on the stent 14, passes through the cavity between the film 13 and the catheter 2, and flows out through the proximal outlet 1301. Figure 24 The direction of the arrow in

[0135] The stiffness of the first diameter section 021 is greater than that of the third diameter section 023, thereby compensating for the pushing feel affected by the thinner diameter of the first diameter section 021. The reason is that: when the user pushes the catheter 2 into the interventional sheath, the user needs to hold the first diameter section 021 of the catheter 2, and then push the collapsible pump head assembly distal to the first diameter section 021 into the sheath of the interventional sheath to fold the pump head assembly so that it is compressed from the radially expanded state to the radially compressed state. If the stiffness of the first diameter section 021 is not enhanced, when the user holds the first diameter section 021 and pushes, due to the large resistance encountered by the pump head assembly when entering the sheath, the first diameter section 021 will bend, resulting in unsmooth pushing of the catheter 2. In addition, if the stiffness of the first diameter section 021 is not enhanced, in order to push the pump head assembly into the sheath, the user will use greater force to pinch the first diameter section 021 and push forward, which may damage the inner wall of the catheter 2 by the flexible transmission shaft 1 inside the catheter 2 and damage its smooth surface. When the flexible transmission shaft rotates, more particulate matter will be generated by friction with the damaged inner wall. Therefore, by enhancing the stiffness of the first diameter section 021, the above problems can be effectively solved, the bending of the first diameter section 021 during the pushing process can be reduced or avoided, the pushing feel can be improved, and the inner wall of the first diameter section 021 can be protected, reducing or avoiding damage to the inner wall of the first diameter section 021 during the pushing process.

[0136] In order to make the stiffness of the first diameter section 021 greater than that of the third diameter section 023, the first diameter section 021 can adopt an inner tube layer 202 or an outer tube layer 205 with greater hardness, or adopt a braided layer 204 with a denser braid, so that the stiffness of the first diameter section 021 is greater.

[0137] Among them, the second diameter section 022 is used to connect the first diameter section 021 and the third diameter section 023, and is a connection transition section between the first diameter section 021 and the third diameter section 023. The stiffness of the second diameter section 022 is greater than that of the third diameter section 023 and less than that of the first diameter section 021. Further, the second diameter section 022 is frustum-shaped, and the diameter of the second diameter section 022 gradually decreases from the proximal end to the distal end, so as to achieve a smooth transition from the third diameter section 023 to the first diameter section 021.

[0138] In one embodiment, the interventional medical device is an interventional blood pump, and the interventional blood pump further includes a pump head assembly, and the pump head assembly is connected to the distal end of the catheter 2; the pump head assembly includes an impeller, and the impeller is connected to the distal end of the flexible transmission shaft 1. In the use state, the interventional medical device is percutaneously inserted into the body of the target object, the pump head assembly is located in the heart 6, and the flexible transmission shaft 1 conducts power to the impeller to drive the impeller to rotate.

[0139] The present invention also discloses a ventricular assist device, which includes a driving assembly 12 and the above-mentioned interventional medical device. In the use state, the driving assembly 12 is located outside the body, and the interventional medical device is at least partially inserted into the body through a catheter 2. The driving assembly 12 drives a flexible transmission shaft 1 to rotate inside the catheter 2. The driving assembly 12 includes a motor 9. Specifically, the interventional medical device is an interventional blood pump.

[0140] In the description of this solution, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "vertical", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to this solution.

[0141] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this solution, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0142] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other.

[0143] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An interventional medical device, characterized in that, It includes a flexible transmission shaft and a catheter sleeved outside the flexible transmission shaft. The catheter includes an inner tube layer, a buffer layer, and a braided layer; The inner wall of the inner tube layer defines the inner cavity of the catheter, and the flexible transmission shaft is rotatably disposed within the inner cavity; The buffer layer is disposed between the outer wall of the inner tube layer and the inner wall of the braided layer. The buffer layer is used to buffer the extrusion of the braided layer on the inner tube layer to maintain the inner wall of the inner tube layer in a smooth and flat form.

2. The interventional medical device according to claim 1, wherein The hardness of the inner tube layer is greater than the hardness of the buffer layer; And / or, the wear resistance of the inner tube layer is superior to the wear resistance of the buffer layer.

3. The interventional medical device according to claim 1 or 2, characterized in that The thickness of the buffer layer is less than the thickness of either the inner tube layer or the braided layer.

4. The interventional medical device according to claim 3, wherein The thickness of the inner tube layer is less than the thickness of the braided layer.

5. The interventional medical device according to claim 4, wherein The catheter further includes an outer tube layer, and the thickness of the outer tube layer is greater than the thickness of the braided layer; The inner tube layer, the buffer layer, the braided layer, and the outer tube layer are relatively fixedly arranged.

6. The interventional medical device according to claim 1 or 2, characterized in that The inner tube layer is a thermosetting polyimide, and the buffer layer is a thermoplastic polyether amide.

7. The interventional medical device according to claim 1, wherein, A support bearing is fixedly arranged within the inner tube layer, and the inner cavity of the support bearing is used to pass through the flexible transmission shaft.

8. The interventional medical device according to claim 7, characterized in that, One or several support bearings are provided; The support bearing is a ceramic bearing.

9. The interventional medical device according to claim 7, wherein At least one glue-containing structure is provided at the position of the inner tube layer for installing the support bearing, and glue for bonding the support bearing is filled within the glue-containing structure.

10. The interventional medical device according to claim 9, wherein, The glue-containing structure includes several glue application holes, and a plurality of the glue application holes are arranged around the axis of the inner tube layer.

11. The interventional medical device according to claim 10, characterized in that, The glue application holes penetrate through the inner tube layer.

12. The interventional medical device according to claim 9, wherein, The glue-containing structure includes several glue application seams, and a plurality of the glue application seams are arranged around the axis of the inner tube layer.

13. The interventional medical device according to claim 7, characterized in that, A glue application area is provided at the position of the inner tube layer for installing the support bearing, and the support bearing is bonded to the glue application area.

14. The interventional medical device according to claim 7, wherein, A cutting tube is fixedly arranged within the inner tube layer, and the support bearing is fixedly arranged within the cutting tube.

15. The interventional medical device according to claim 14, characterized in that, The cutting tube and the support bearing are clamped through a clamping structure.

16. The interventional medical device according to claim 15, wherein The clamping structure includes a first clamping portion and a second clamping portion that are cooperatively arranged; One of the cutting tube and the support bearing is provided with the first clamping portion, and the other is provided with the second clamping portion. The first clamping portion and the second clamping portion are arranged in one-to-one correspondence.

17. The interventional medical device according to claim 15, characterized in that, The cutting tube includes a connection area and a cutting area. The clamping structure is provided on the connection area, and the clamping structure is connected to the support bearing. Cutting openings are provided on the cutting area.

18. The interventional medical device according to any one of claims 7 to 17, characterized in that, The catheter further includes an outer tube layer; At least one of the buffer layer and the braided layer is disposed between the outer tube layer and the inner tube layer, or, the buffer layer and the braided layer are cancelled, and the outer tube layer is directly sleeved on the outer wall of the inner tube layer.

19. The interventional medical device according to claim 7, wherein, When in use, the catheter includes at least two segments passing through blood vessels with different bending radii. The at least two segments include a first segment and a second segment. The bending radius of the first segment is less than the bending radius of the second segment, and the corresponding arrangement spacing of the support bearings within the first segment is less than the corresponding arrangement spacing of the support bearings within the second segment; Optionally, the first section includes a femoral arch section of the catheter passing through the femoral arch, and the second section includes a main arch section of the catheter passing through the aortic arch.

20. The interventional medical device according to claim 7, wherein, When in use, the catheter includes at least two sections passing through blood vessels with different bending radii. The at least two sections include a third section and a fourth section. The third section and the fourth section are adjacent. The bending radius of the third section is smaller than that of the fourth section, and the corresponding arrangement spacing of the support bearings in the third section is greater than or equal to the corresponding arrangement spacing of the support bearings in the fourth section. Optionally, the third section is the main arch section of the catheter passing through the aortic arch, and the fourth section is the sub-arch large bend section of the catheter passing through the large bend under the aortic arch. The corresponding arrangement spacing of the support bearings in the main arch section is equal to the corresponding arrangement spacing of the support bearings in the sub-arch large bend section, and the number of bearings arranged in the main arch section is greater than the number of bearings arranged in the sub-arch large bend section. Optionally, the third section is the main arch section of the catheter passing through the aortic arch, and the fourth section is a variable diameter section of the catheter located distal to the main arch section. The distal end of the variable diameter section of the catheter is connected to the pump head assembly of the interventional medical device. The corresponding arrangement spacing of the support bearings in the main arch section is greater than the corresponding arrangement spacing of the support bearings in the variable diameter section of the catheter, and the number of bearings arranged in the main arch section is greater than the number of bearings arranged in the variable diameter section of the catheter. Preferably, the corresponding arrangement spacing of the support bearings in the variable diameter section of the catheter is the smallest; the variable diameter section of the catheter is substantially in a straight state when in use.

21. The interventional medical device according to claim 7, wherein, The catheter includes an in-vivo section that intervenes in the body during use, an in-vitro section located outside the body, and an in-vivo and in-vitro connection section located between the in-vivo section and the in-vitro section. The corresponding arrangement spacing of the support bearings in the in-vivo and in-vitro connection section is smaller than the corresponding arrangement spacing of the support bearings in the in-vitro section.

22. The interventional medical device according to claim 7, wherein The catheter includes at least two sections with different bending states during use. The at least two sections include a fifth section and a sixth section. The fifth section includes some or all of the pipe sections that are substantially in a bent state when the catheter is in use, and the sixth section includes some or all of the pipe sections that are substantially in a straight state when the catheter is in use. The corresponding arrangement spacing of the support bearings in the fifth section is smaller than the corresponding arrangement spacing of the support bearings in the sixth section.

23. The interventional medical device according to any one of claims 19 to 22, characterized in that, The catheter includes a variable diameter section, a main arch section, a sub-arch large bend section, a near-straight section, a femoral arch section, an in-vivo and in-vitro transition section, and an in-vitro section distributed from the distal end to the proximal end. At least one of the variable diameter section, the main arch section, the sub-arch large bend section, the near-straight section, the femoral arch section, the in-vivo and in-vitro transition section, and the in-vitro section is provided with the support bearings.

24. The interventional medical device according to claim 1, wherein The interventional medical device further includes a rotor shaft. The proximal end of the flexible transmission shaft extends out of the catheter and is fixedly connected to the rotor shaft, and the rotor shaft drives the flexible transmission shaft to rotate. There is a gap between the distal end of the rotor shaft and the proximal end of the catheter, and the flexible transmission shaft includes a free section between the distal end of the rotor shaft and the proximal end of the catheter. The length of the free section is maintained at a first distance.

25. The interventional medical device according to claim 24, wherein, The first distance is 3 - 5 mm.

26. The interventional medical device according to claim 24, wherein, The interventional medical device further includes a coupling assembly. The rotor shaft and the proximal end of the catheter are disposed within the coupling assembly. The coupling assembly has a flushing fluid chamber, and the free section is located within the flushing fluid chamber.

27. The interventional medical device according to claim 1, wherein The catheter includes a proximal end portion, an intermediate portion, and a distal end portion. The intermediate portion is disposed between the proximal end portion and the distal end portion. The braided layer is disposed on the intermediate portion. The proximal end of the braided layer is distal to the proximal end portion of the catheter, and the distal end of the braided layer is proximal to the distal end portion of the catheter.

28. The interventional medical device according to claim 27, wherein The proximal end portion and the distal end portion of the catheter are the portions where the catheter is cut.

29. The interventional medical device according to claim 1, wherein The outer wall of the inner tube layer is subjected to plasma treatment; a buffer layer is disposed on the outer wall of the inner tube layer after plasma treatment, and the braided layer is woven on the outer wall of the buffer layer.

30. The interventional medical device according to claim 1, wherein It further includes a film. The catheter includes a first diameter section, a second diameter section, and a third diameter section arranged in sequence. The first diameter section is disposed within the film. The second diameter section is disposed at the proximal end of the film, and the second diameter section is continuously arranged with the first diameter section; the third diameter section is disposed at the proximal end of the second diameter section and is continuously arranged with the second diameter section. The diameter of the first diameter section is smaller than the diameter of the third diameter section, and the stiffness of the first diameter section is greater than the stiffness of the third diameter section.

31. The interventional medical device according to claim 30, wherein The stiffness of the second diameter section is greater than the stiffness of the third diameter section and less than the stiffness of the first diameter section.

32. The interventional medical device according to claim 30, wherein, The second diameter section is frustum-shaped, and the diameter of the second diameter section gradually decreases from the proximal end to the distal end.

33. The interventional medical device according to claim 1, wherein The interventional medical device is an interventional blood pump. The interventional blood pump further includes a pump head assembly. The pump head assembly is connected to the distal end of the catheter; the pump head assembly includes an impeller, and the impeller is connected to the distal end of the flexible transmission shaft. In the use state, the interventional medical device is percutaneously inserted into the body of the target object. The pump head assembly is located within the heart, and the flexible transmission shaft conducts power to the impeller to drive the impeller to rotate.

34. A ventricular assist device, characterized in that, It includes a driving assembly and the interventional medical device according to any one of claims 1 to 33. In the use state, the driving assembly is located outside the body, and at least part of the interventional medical device is inserted into the body through the catheter. The driving assembly drives the flexible transmission shaft to rotate within the catheter.

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