CN113729848A

CN113729848A - Thrombus cutter

Info

Publication number: CN113729848A
Application number: CN202110532862.9A
Authority: CN
Inventors: 沈斌
Original assignee: Guangzhou Boxin Medical Technology Co ltd
Current assignee: Jiaxing Jiachuangzhi Medical Equipment Co ltd
Priority date: 2021-05-17
Filing date: 2021-05-17
Publication date: 2021-12-03
Anticipated expiration: 2041-05-17
Also published as: CN113729848B

Abstract

The invention provides a thrombus resectoscope which comprises a guide pipe and a resectoscope component, wherein the resectoscope component comprises a knife net, a knife head, a transmission shaft and a power source, the knife net is fixed on the end surface of the guide pipe, a hollow part is arranged on the knife net, the knife head is connected to one end of the transmission shaft, at least one part of the knife head and at least one part of the transmission shaft are positioned in the guide pipe, and the power source drives the knife head to rotate in the guide pipe through the transmission shaft; the cutter head is a semicircular ring-like body, the surface of the cutter head close to the cutter net is a first surface, and the first edge and the third edge of the cutter head are respectively connected with the two ends of the second edge and the fourth edge; the tool bit with the sword net forms cutting structure, cutting structure includes first cutting edge and second cutting edge, first border and third border constitute first cutting edge, the second cutting edge is located on the sword net. The thrombectomy device provided by the invention has the advantages of good thrombectomy effect and the like.

Description

Thrombus cutter

Technical Field

The invention relates to the field of medical instruments, in particular to a thrombus resectoscope.

Background

Thrombi are small pieces of blood formed on the surface of the inner vascular denuded or repaired site of the cardiovascular system and are composed of insoluble fibrin, deposited platelets, accumulated white blood cells and entrapped red blood cells. Thrombus causes the local blood flow reduction or blood supply interruption of the brain, and the ischemia and anoxia of brain tissues cause softening necrosis to generate focal nervous system symptoms, so that the atherosclerotic brain or heart infarction is caused. When thrombus occurs, because local tissues are subjected to blood vessel blockage and ischemia, the activity and important physiological functions of nerve centers are threatened, if the blockage in the blood vessel cannot be cleared in time, the blood flow is unobstructed, and the brain tissues in the ischemic area cause dysfunction or lose the functions of the brain tissues, and even seriously threaten the life of a patient. However, the current medical treatment generally applied in clinic cannot remove thrombus and remove blockage quickly, and the dilatation, anticoagulation and thrombolysis treatments adopted by the method have poor curative effect, limit treatment time window and even have serious consequences of tissue bleeding easily. The treatment of thrombosis remains a clinical medical problem.

Disclosure of Invention

In view of the above-described situation, a main object of the present invention is to provide a thrombectomy device.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a thrombus resectoscope is used for resecting thrombus in a blood vessel and comprises a catheter and a resecting assembly, wherein the resecting assembly comprises a knife net, a knife head, a transmission shaft and a power source, the knife net is fixed on the end face of the catheter, a hollow part is arranged on the knife net, the knife head is connected to one end of the transmission shaft, the power source is connected to the other end of the transmission shaft, at least one part of the knife head and at least one part of the transmission shaft are positioned in the catheter, and the power source drives the knife head to rotate in the catheter through the transmission shaft; the cutter head is a semicircular ring-like body, the surface of the cutter head close to the cutter mesh is a first surface, the first surface is a plane and is provided with a first edge, a second edge, a third edge and a fourth edge which are sequentially connected, wherein the second edge and the fourth edge are arc-shaped, and the first edge and the third edge are respectively connected with two ends of the second edge and the fourth edge; the tool bit with the sword net forms cutting structure, cutting structure includes first cutting edge and second cutting edge, first border and third border constitute first cutting edge, the second cutting edge is located on the sword net.

Preferably, the first surface is parallel to the reference plane a; or an included angle is formed between the first surface and the reference surface A, the first edge and the third edge are the parts of the cutter head, which are closest to the cutter mesh, wherein the reference surface A is perpendicular to the rotating shaft of the cutter head.

Preferably, the projection of the first surface on the reference plane a is semicircular.

Preferably, the cutter head is provided with a first plane and a second plane which extend along the axial direction of the cutter head, and an arc surface which connects the first plane and the second plane, one ends of the first plane and the second plane, which are close to the cutter mesh, are both provided with a notch, one side of the notch, which is close to the cutter mesh, is provided with a sharp corner structure, and the sharp corner structure comprises a tip which forms the first cutting edge.

Preferably, the notch is provided with a first notch surface and a second notch surface, the first notch surface is in arc smooth connection with the second notch surface, an included angle between the first notch surface and the second notch surface is 80-120 degrees, the first notch surface is a side surface of the sharp-angled structure, the included angle between the first notch surface and a reference surface A is 15-35 degrees, and the reference surface A is perpendicular to the rotating shaft of the cutter head.

Preferably, the first plane and the second plane are coplanar, extension lines of the first blades on the two sharp-angled structures are collinear and pass through a rotation center of the cutter head, a plane where the first plane and the second plane are located is higher than a line where the first blade is located, and a height difference between the plane where the first plane and the second plane are located and the line where the first blade is located is 10% -30% of an outer diameter of the cutter head.

Preferably, the length of each of the first cutting edges is 20-40% of the outer diameter of the cutting head.

Preferably, the knife net comprises a knife net main body, the knife net main body comprises an outer annular structure and connecting ribs arranged in the radial direction of the outer annular structure, one end of each connecting rib is connected with the outer annular structure, the other end of each connecting rib is connected with the center of the outer annular structure, hollow parts are formed between the adjacent connecting ribs, and the surfaces, close to the cutter heads, of the connecting ribs are parallel to the reference surface A or form included angles with the reference surface A; the cutter head moves along the axial direction of the guide pipe to be in contact with the cutter mesh, and when the cutter head rotates, the edge of the cutter mesh, which is in contact with the cutter head first, forms the second cutting edge; wherein the reference plane A is perpendicular to the axis of rotation of the cutting head.

According to the thrombus resectoscope provided by the invention, thrombus can be resected through the matching of the catheter, the resection component and the suction component, the knife net and the knife head are simple in structure design and exquisite in matching, and the resection effect of thrombus is improved. Specifically, sword net and tool bit cooperation form the cutting structure of excision thrombus, and the first cutting edge of cutting structure is located on the tool bit, the tool bit is type semicircle ring body, and the first border and the third border of tool bit first surface constitute first cutting edge, and the second cutting edge of cutting structure is located on the sword net, can effectively excise the thrombus through cutting structure. Because the knife net is fixed on the end surface of the catheter, the thrombus can be effectively cut off by the thrombus cutter under the condition that the thrombus is large in size, namely, the blood vessel is blocked or is blocked, and the thrombus cutter is not influenced by the size of the thrombus.

The first cutting edge in the cutting structure of the thrombectomy device can also be formed by the tip of a sharp-angled structure, and the design of the sharp-angled structure is beneficial to breaking and removing thrombi and improving the cutting efficiency of the thrombi.

Other advantages of the present invention will be described in the detailed description, and those skilled in the art will understand the technical features and technical solutions presented in the description.

Drawings

Preferred embodiments of the thrombectomy device according to the present invention will be described below with reference to the accompanying drawings. In the figure:

FIG. 1 is a perspective view of a thrombectomy device of the present invention.

FIG. 2 is a schematic diagram of an exploded structure of the thrombectomy device of the present invention.

FIG. 3 is a perspective view of a first catheter of the thrombectomy device of the present invention.

FIG. 4 is a cross-sectional view of a first catheter in the thrombectomy device of the present invention.

FIG. 5 is an exploded view of a cutting assembly of the thrombectomy device of the present invention.

FIGS. 6 and 7 are schematic perspective views of a cutting head of the thrombectomy device of the present invention at different viewing angles.

FIG. 8 is a side view of a cutting head of the thrombectomy device of the present invention.

FIG. 9 is a front view of a cutting head of the thrombectomy device of the present invention.

FIG. 10 is a perspective view of a mesh in the thrombectomy device of the present invention.

FIG. 11 is a rear view of a mesh in the thrombectomy device of the present invention.

FIG. 12 is a schematic diagram of a deformed structure of a knife net in the thrombectomy device of the present invention.

FIG. 13 is a schematic diagram of a deformed structure of a knife net body in the thrombectomy device of the present invention.

FIG. 14 is a schematic diagram of a thrombus exciser of the present invention.

Detailed Description

The present invention will be described below based on examples, but the present invention is not limited to only these examples. In the following detailed description of the present invention, certain specific details are set forth in order to avoid obscuring the nature of the present invention, well-known methods, procedures, and components have not been described in detail.

Further, those of ordinary skill in the art will appreciate that the drawings provided herein are for illustrative purposes and are not necessarily drawn to scale.

Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is, what is meant is "including, but not limited to".

In the description of the present invention, it is to be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

Referring to FIG. 1, the present invention provides a thrombectomy device 10 for removing thrombi from within a blood vessel. The thrombectomy device 10 enters the appointed position of the blood vessel under the guidance of the guide wire 20 to excise the thrombus. The types of thrombus include but are not limited to cerebral thrombosis, pulmonary thrombosis, cardiac thrombosis, and the like.

The thrombectomy device 10 comprises a catheter 11, a cutting assembly 12 and a suction assembly 13, wherein the catheter 11 extends into a blood vessel, one end of the catheter 11 moves to the position of thrombus, and the cutting assembly 12 is driven by the catheter 11 to move to the position of the thrombus to cut the thrombus. The suction assembly 13 is communicated with the inner cavity of the catheter 11 and used for sucking air from the interior of the catheter 11 when the thrombectomy device 10 works so that the interior of the catheter 11 is in a negative pressure state, when thrombus is sucked into the catheter 11 from the end face, extending into a blood vessel, of the catheter 11 under the action of the negative pressure, the thrombectomy assembly 12 is used for excising the thrombus, and the excised thrombus is sucked away under the action of suction force generated by the suction assembly 13.

Referring to fig. 2, the conduit 11 is a circular hollow tube made of flexible material. The catheter 11 can extend into the blood vessel and be deformed to conform to the trend of the blood vessel, so that the catheter is beneficial to delivery in the curved blood vessel. The duct 11 comprises a first duct 111 and a second duct 112, the first duct 111 and the second duct 112 communicating through the suction assembly 13. The catheter 11 has opposite ends in the axial direction, and for convenience of description, one end of the catheter 11 extending into the blood vessel is defined as a distal end 11a, and the other end is defined as a proximal end 11 b. It will be appreciated that the duct 11 may also be formed not by a segmented first duct 111 and second duct 112, but by a complete duct, in which the suction assembly 13 communicates with said duct 11 by providing openings (not shown) in the side walls of the duct.

Referring to fig. 3 and 4, the distal end 11a of the catheter 11, i.e., the outer side wall of the end of the first catheter tube 111 extending into the blood vessel, is provided with a snap groove 113 for snap-fitting of some components of the ablation assembly 12. The catching groove 113 has a wedge shape. The number of the catching grooves 113 is at least 2, and they are arranged symmetrically with respect to the axial center of the guide tube 11. It is understood that the shape of the clamping groove 113 is not limited, and it may be triangular prism, trapezoidal or other regular or irregular shapes as long as the clamping function can be achieved. As a specific example of the click groove 113 for clicking, the click groove 113 is gradually increased in depth from the distal end 11a to the proximal end 11b in the axial direction of the catheter tube 11 to click the partial elements of the resection member 12.

As an example, the catheter 11 has an inner diameter d1 of 1.3mm to 1.9mm and an outer diameter d2 (diameter) of 2.8mm to 3.4 mm. Preferably, the outer diameter of the conduit 11 is 3.1mm to 3.3mm, optionally 3.18 mm. The inner diameter of the conduit 11 is 1.5mm to 1.7mm, optionally 1.59 mm.

Referring to fig. 5, the cutting assembly 12 includes a power source 15, a transmission shaft 16, a cutter head 17 and a cutter net 18, wherein one end of the transmission shaft 16 is connected to the power source 15, the other end is connected to the cutter head 17, and the power source 15 drives the cutter head 17 to rotate through the transmission shaft 16. The knife net 18 is fixed on the end face of the distal end 11a of the catheter 11, and during the operation of the thrombectomy device 10, the knife net 18 and the knife head 17 cooperate to form at least one cutting structure which generates shearing force applied to the thrombus, so that the thrombus is cut. The cutting structure comprises cooperating first and second blades (described in more detail below), the first blade being located on the blade 17 and the second blade being located on the foil 18.

The power source 15 may be any device capable of driving a connecting member to rotate, such as a driving motor or a driving motor. The power source 15 includes a power output shaft of the power source 15 connected to one end of the transmission shaft 16, and a first sealing member (neither shown) disposed between the transmission shaft 16 and the guide tube 11 for sealing the proximal end 11b of the guide tube 11 so that the interior of the guide tube 11 is a relatively closed space.

The drive shaft 16 has some flexibility to facilitate delivery within a curved vessel. The transmission shaft 16 is hollow, i.e. forms a first through hole, and the hollow penetrates through two opposite ends of the transmission shaft 16. The hollow structure is for the guide wire 20 to pass through.

As an example, the transmission shaft 16 includes m layers of spiral wire tubes stacked in this order from the inside to the outside; each layer of the spiral wire tube is formed by winding n strands of thin wires 161 side by side, and a hollow structure is formed along the axis of the transmission shaft after winding; when the spiral wire tube is multilayer, the winding directions of two adjacent layers of spiral wire tubes are opposite.

In a preferred embodiment, the filaments 161 are metal wires, which are 316LVM stainless steel wires or 40CrMoV alloy steel wires or 35NLT alloy wires.

As an embodiment, the transmission shaft 16 is formed by winding 3 metal wires with the diameter of 0.18mm, and under the above parameters, the transmission shaft 16 is not easy to break, and the torque transmission and the bearing capacity are better. The distance between the drive shaft 16 and the inner wall of the catheter 11 is set to a value which determines the maximum size of the excised thrombus which can pass through, and in the present invention, the distance is 0.3mm to 0.7 mm.

The transmission shaft 16 formed by winding n strands of filaments 161 side by side and with opposite winding directions of two adjacent layers of spiral filament tubes has excellent torque transmission performance and bearing capacity on one hand, is not easy to break and has excellent safety performance on the other hand.

A gap of suitable size is provided between the drive shaft 16 and the catheter tube 11 to allow the excised thrombus to pass through the gap into the aspiration assembly 13. As an example, the size of the gap between the transmission shaft 16 and the guide tube 11 is 0.3mm-0.7 mm.

Referring to fig. 6 to 9, the cutting head 17 is a semicircular-like body, a plane perpendicular to the rotation axis of the cutting head 17 is defined as a reference plane a, the semicircular-like body, i.e., the projection of the cutting head 17 on the reference plane a, is an unsealed ring, and a central angle corresponding to the ring may be smaller than 90 °, or larger than 90 °, preferably equal to 90 °, so that the cutting efficiency is guaranteed, and the processing is facilitated.

The surface of the tool bit 17 adjacent to the mesh 18 is a first surface 170, the first surface 170 is a plane, the first surface 170 has a first edge 1701, a second edge 1702, a third edge 1703 and a fourth edge 1704 which are connected in sequence, wherein the second edge 1702 and the fourth edge 1704 are arc-shaped, and the first edge 1701 and the third edge 1703 are straight lines. The first edge 1701 and the third edge 1703 connect both ends of the second edge 1702 and the fourth edge 1704, respectively. The first surface 170 is parallel to the reference plane a, or the first surface 170 and the reference plane a have an included angle therebetween, and the first edge 1701 and the third edge 1703 are the nearest portions of the tool tip 17 to the blade net 18. Preferably, the projection of the first plane 170 on the reference plane a is semicircular.

The cutter head 17 is provided with a first plane 171 and a second plane 172 which extend along the axial direction of the cutter head 17, and an arc 173 connecting the first plane 171 and the second plane 172, one end of the first plane 171 and/or the second plane 172, which is close to the cutter mesh 18, is provided with a notch 174, a pointed structure 175 is formed on one side of the notch 174, which is close to the cutter mesh 18, and the pointed structure 175 comprises a pointed end 1751, namely the first edge 1701 and the third edge 1703 which extend along the radial direction. The cambered surface 173 may also be a bevel or other irregular surface, etc. Preferably, the first plane 171 and the second plane 172 are also parallel to the radial direction of the cutter head 17.

The opening is provided with a first opening surface 174a and a second opening surface 174b, the first opening surface 174a is in arc smooth connection with the second opening surface 174b, the included angle between the first opening surface 174a and the second opening surface 174b is 80-120 degrees, preferably 90-100 degrees, wherein the first opening surface 174a is the side surface of the pointed structure 175, and the included angle between the first opening surface 174a and the reference surface A is 15-35 degrees, preferably 20-30 degrees. Under the parameters, the sharpness of the cutter head 17 and the smoothness of the removal of the removed thrombus can be considered.

The cutting head 17 and the mesh 18 form a cutting structure for cutting thrombi, the cutting structure comprising a first edge 1701 and a second edge 1703, the first edge, i.e. the tip 1751, constituting the first edge, the second edge being located on the mesh 18. When the cutter head 17 approaches the cutter mesh 18, the first cutter edge is the part of the cutter head 17 which is firstly contacted with the cutter mesh 18, and the first cutter edge is matched with the cutter mesh 18 to generate shearing force on thrombus sucked into the catheter from the cutter mesh 18, so that the thrombus is cut.

The first plane 171 is coplanar with the second plane 712, the extensions of the first edges of the two pointed structures 175 are collinear and pass through the center of rotation of the tool tip 17, the first plane 171 and the second plane 172 lie on a plane higher than the line on which the first edge lies, and the difference in height between the plane on which the first plane 171 and the second plane 172 lie and the line on which the first edge lies is 10% -30% of the outer diameter of the tool tip 17. Such a design facilitates both manufacturing and secure attachment to the drive shaft 16. The length of the first cutting edge is 20% to 40% of the outer diameter of cutting head 17, providing a suitable amount of cutting and reducing the likelihood of the first cutting edge coming into contact with catheter 11.

As an example, the cutting head 17 is made of a metal material. As a variant, the provision of the break-outs 174 may be omitted, i.e. the cutting head 17 is free of pointed formations 175.

The transmission shaft 16 is fixedly connected to the inner wall of the cutter head 17, and the fixed connection mode of the transmission shaft 16 and the cutter head 17 can be any mode capable of realizing the fixed connection of the transmission shaft 16 and the cutter head 17, such as welding, clamping or bonding.

Referring to fig. 10 and 11, the knife net 18 includes a knife net main body 181 and a fixing member 182, and the knife net main body 181 and the fixing member 182 are fixedly connected, and the fixing connection may be integrally formed or may be fixedly connected by welding or other processes after being separately formed. The knife net 18 is fixed to the catheter 11 by a fixing member 182. Specifically, the fixing member 182 is snapped in the snap groove 113 of the guide tube 11. The number of the fixing members 182 is at least two, and the fixing members are symmetrically arranged with respect to the center of the knife net 18 and are positioned corresponding to the positions of the catching grooves 113 on the guide tube 11. The present invention is described by taking two fixing members 182 as an example. The fixing member 182 is a sheet-shaped body having a shape of a Chinese character 'yi', one end of which is connected to the knife net main body 181, and the other end of which is inclined toward the center of the knife net 18, and the distance from the fixing member 182 to the axis of the knife net 18 gradually decreases from the end where the fixing member 182 is connected to the knife net main body 181 to the end away from the knife net main body 181. When the fixing member 182 is snapped into the snap groove 113, the fixing member 182 is clamped on the inner wall of the snap groove 113. The fixing member 182 and the clamping groove 113 have the advantages of simple clamping structure, simple clamping operation, stable connection and convenience in manufacture by matching the shapes and the sizes.

It will be appreciated that the fastener 182 is not limited to being connected to the conduit 11 by snapping, and may be connected to the conduit 11 by other possible means such as adhesive. Most preferably by snap-fit attachment.

The knife net body 181 includes an outer annular structure 1812, an inner annular structure 1813, and a connecting rib 1811, and the connecting rib 1811 is integrally formed with the outer annular structure 1812 and the inner annular structure 1813. The outer ring structure 1812 and the inner ring structure 1813 are circular and coaxially arranged, and the inner ring structure 1813 is provided with a second through hole 1817 in the middle for the guide wire 20 to pass through. The connecting ribs 1811 are secured at one end to the outer annular structure 1812 and at one end to the inner annular structure 1813. The connecting ribs 1811 extend in a radial direction of the inner annular structure 1813 or the outer annular structure 1812, and are uniformly distributed between the outer annular structure 1812 and the inner annular structure 1813, the number of the connecting ribs 1811 is not limited, and is at least 2, and 4 connecting ribs 1811 are exemplified in the present invention. Hollow-out portions 1814 are formed between adjacent connecting ribs 1811, and the hollow-out portions 1814 are used for blood embolus to enter the interior of the catheter 11. Fasteners 182 are attached to the outer side of the outer ring structure 1812. The outer annular structure 1812 has an outer diameter slightly smaller than the outer diameter of the catheter 11 (the difference between the two diameters is 0.01-0.8mm), and when the knife net 18 is fixed on the end face of the distal end 11a of the catheter 11, the outer annular structure 1812 and the inner annular structure 1813 are coincident with the axial center of the catheter 11. The inner annular structure 1813 is located at the center of the outer annular structure 1812 or the conduit 11 and the ends of the connector ribs 1811 can be considered to be fixedly connected together at the center of the outer annular structure 1812 or the conduit 11. Preferably, the maximum dimension of the knife net 18 along the radial direction is smaller than the outer diameter of the catheter 11, so that when the catheter 11 drives the knife net 18 to move in a blood vessel, the knife net 18 is not easy to contact with the inner wall of the blood vessel, the blood vessel is effectively protected, and the knife net 18 can be prevented from falling off easily due to resistance.

Referring to fig. 10 and 11, the connecting ribs 1811 are bars having an equal thickness. The surface of the connecting rib 1811 close to the cutting head 17 is parallel to the reference plane a, and in the rotation direction of the cutting head 17, the edge n3 of the connecting rib 1811 close to the cutting head 17 and contacting or approaching the first cutting edge in the rotation of the cutting head 17 is the second cutting edge, that is, the part of the edge defining the hollow 1814 forms the second cutting edge. When the thrombus excider works, the cutter head 17 rotates, the connecting rib 1811 is fixed, namely the first cutter edge rotates, the second cutter edge is fixed, and the first cutter edge and the second cutter edge are matched to excise thrombus. Various connecting ribs 1811 may cooperate with the cutting head 17 to form cutting structures. The first cutting edge and the second cutting edge are in a straight line shape and extend along the radial direction of the conduit 11.

As a preferred embodiment, the thickness of the main body 181 is the same, i.e., the outer ring 1812, the inner ring 1813 and the connecting ribs 1811 are the same thickness. As another embodiment, the knife net 18 has the same thickness, that is, the outer annular structure 1812, the inner annular structure 1813, the connecting ribs 1811 and the fixing members 182 have the same thickness, and can be made of the same plate material, the knife net main body 181 and the corresponding parts of the fixing members (pre-fixing members) are cut from the plate material, and then the pre-fixing members are bent to form the fixing members 182, which has the advantages of simplified manufacturing process and good overall strength of the product.

Referring to fig. 12, as an example, the connecting ribs 1811 are strips with unequal thickness. The surface of the connecting rib 1811 close to the cutting head 17 is an inclined plane relative to the reference plane a, and the edge n4 of the connecting rib 1811 closest to the cutting head 17 is a second cutting edge, that is, the partial edge defining the hollow portion constitutes the second cutting edge. . The second cutting edge may be sharper to improve thrombectomy efficiency. Preferably, the inclined plane is parallel to the first surface 1711.

It will be appreciated that the cutting head 17 is moved in the axial direction of the conduit 11 into contact with the foil 18, and that the edge of the foil 18 which first contacts the cutting head 17 constitutes the second cutting edge when the cutting head 17 is rotated.

The knife net 18 is preferably made of metal, and is manufactured through a stamping and bending process, that is, the knife net 18 is stamped through a metal plate to obtain the knife net main body 181 and a pre-fixing piece connected to the knife net main body, and the pre-fixing piece is bent to form the fixing piece 182. As a variation, the outer ring structure 1812 of the main body 181 may be omitted and the connecting ribs 1811 may be directly connected to the fixing member 182.

It is to be understood that the structure of the knife net body 181 is not limited to the above embodiment, and as shown in fig. 13, the knife net body 181 is a plate-shaped body with a hollowed-out portion 1814. The portion of the edge n5 defining the cutout 1814 on the blade net 18 (and near the cutting head 17) is the second cutting edge. In this case, the portion outside the hollowed-out portion 1814 corresponds to an outer ring structure.

In the inactive state, a distance of less than or equal to 2mm, more preferably less than or equal to 1mm, is provided between the cutting head 17 and the mesh 18, which facilitates the entry of thrombus from the hollowed-out portion 1814 into the catheter 11. In the working state, the power source 15 can drive the cutter head 17 to approach the cutter net 18 through the driving transmission shaft 16, and the cutter net 18 is contacted with the cutter head 17 to generate a shearing force with higher strength. It will be appreciated that in the operative condition of the thrombectomy device, a slight clearance is also allowed between the mesh 18 and the cutting head 17.

The suction assembly 13 is used to suck the inside of the duct 11 so that the inside of the duct 11 is in a negative pressure state. The suction assembly 13 comprises a three-way pipe, a suction port, a thrombus collection cavity and a second sealing element (not numbered), the suction assembly 13 is connected with the suction port, the first catheter 111 and the second catheter 112 through the three-way pipe, and the second sealing element is arranged at the joint of the three-way pipe, the suction port and the catheter 11 to ensure sealing connection. The excised thrombus is sucked into the thrombus collecting cavity through the suction port under the negative pressure state. As an example, the suction assembly 13 comprises a vacuum pump.

Referring to fig. 14, when the thrombectomy device 10 works, the thrombectomy device 10 passes through the guide wire 20, that is, the guide wire 20 passes through the through hole formed in the power output shaft, the first through hole of the transmission shaft 16, the axial center of the cutter head 17 and the second through hole 1817, and the guide wire 20 guides the thrombectomy device 10 to move to the position of the thrombus. Under the action of external force, the transmission shaft 16 and the cutter head 17 move along the axial direction of the catheter 11, so that the cutter head 17 is sent to the vicinity of the cutter mesh 18, and the guide wire 20 guides the thrombus cutter 10 to move to the position of thrombus. The cutting head 17 may be stationary or may be rotated at a low speed, preferably 0-20000rpm, before cutting the thrombus. When the thrombus is to be cut, the power source 15 drives the cutter head 17 to rotate at a high speed by taking the guide wire 20 as an axis through the transmission shaft 16, and simultaneously, the cutter head 17 approaches the cutter mesh 18 to enable the cutter mesh and the cutter mesh to be in contact or enable a small gap to exist between the cutter head 17 and the cutter mesh, and a first cutting edge on the cutter head 17 and a second cutting edge on the cutter mesh 18 are matched to generate shearing force on the thrombus entering from the hollow part 1814, so that the cut of the thrombus is completed. During cutting, the cutting head 17 is rotated at high speed, preferably at a speed of 60000rpm-200000 rpm.

It will be appreciated by those skilled in the art that the above-described preferred embodiments may be freely combined, superimposed, without conflict.

It will be understood that the embodiments described above are illustrative only and not restrictive, and that various obvious and equivalent modifications and substitutions for details described herein may be made by those skilled in the art without departing from the basic principles of the invention.

Claims

1. A thrombectomy device for removing thrombi from a blood vessel, comprising: the thrombus resectoscope comprises a catheter and a resecting assembly, the resecting assembly comprises a knife net, a knife head, a transmission shaft and a power source, the knife net is fixed on the end surface of the catheter, a hollow part is arranged on the knife net, the knife head is connected to one end of the transmission shaft, the power source is connected to the other end of the transmission shaft, at least one part of the knife head and at least one part of the transmission shaft are positioned in the catheter, and the power source drives the knife head to rotate in the catheter through the transmission shaft;

the cutter head is a semicircular ring-like body, the surface of the cutter head close to the cutter mesh is a first surface, the first surface is a plane and is provided with a first edge, a second edge, a third edge and a fourth edge which are sequentially connected, wherein the second edge and the fourth edge are arc-shaped, and the first edge and the third edge are respectively connected with two ends of the second edge and the fourth edge;

the tool bit with the sword net forms cutting structure, cutting structure includes first cutting edge and second cutting edge, first border and third border constitute first cutting edge, the second cutting edge is located on the sword net.

2. The thrombectomy device of claim 1, wherein: the first surface is parallel to a reference plane A; or an included angle is formed between the first surface and the reference surface A, the first edge and the third edge are the parts of the cutter head, which are closest to the cutter mesh, wherein the reference surface A is perpendicular to the rotating shaft of the cutter head.

3. The thrombectomy device of claim 2, wherein: the projection of the first surface on the reference surface A is semicircular.

4. The thrombectomy device of claim 1, wherein: the cutter head is provided with a first plane and a second plane which extend along the axial direction of the cutter head, and an arc surface which connects the first plane and the second plane, one ends of the first plane and the second plane, which are close to the cutter mesh, are respectively provided with a gap, one side of the gap, which is close to the cutter mesh, is provided with a sharp corner structure, and the sharp corner structure comprises a tip which forms the first cutting edge.

5. The thrombectomy device of claim 4, wherein: the notch is provided with a first notch surface and a second notch surface, the first notch surface is in arc smooth connection with the second notch surface, an included angle between the first notch surface and the second notch surface is 80-120 degrees, the first notch surface is a side surface of the sharp-angled structure, the included angle between the first notch surface and a reference surface A is 15-35 degrees, and the reference surface A is perpendicular to the rotating shaft of the cutter head.

6. The thrombectomy device of claim 4, wherein: the first plane and the second plane are coplanar, extension lines of the first cutting edges on the two sharp corner structures are collinear and pass through the rotation center of the cutter head, the plane where the first plane and the second plane are located is higher than the line where the first cutting edge is located, and the height difference between the plane where the first plane and the second plane are located and the line where the first cutting edge is located is 10% -30% of the outer diameter of the cutter head.

7. The thrombectomy device of claim 4, wherein: the length of each first cutting edge is 20-40% of the outer diameter of the cutter head.

8. The thrombectomy device of any one of claims 1-7, wherein: the knife net comprises a knife net main body, the knife net main body comprises an outer annular structure and connecting ribs arranged in the radial direction of the outer annular structure, one end of each connecting rib is connected with the outer annular structure, the other end of each connecting rib is connected with the center of the outer annular structure, the hollow parts are formed between the adjacent connecting ribs, and the surfaces, close to the knife heads, of the connecting ribs are parallel to the reference surface A or form included angles with the reference surface A; the cutter head moves along the axial direction of the guide pipe to be in contact with the cutter mesh, and when the cutter head rotates, the edge of the cutter mesh, which is in contact with the cutter head first, forms the second cutting edge; wherein the reference plane A is perpendicular to the axis of rotation of the cutting head.