Intravascular ultrasonic vibration assisted rotary grinding apparatus

Abstract

To provide an intravascular ultrasonic vibration assisted rotary grinding device having improved controllability during vibration grinding operation and improved accuracy of vibration grinding.SOLUTION: The ultrasonic transducer is embedded inside the grinding head, so that the vibration generated by the ultrasonic transducer can directly drive the grinding head to vibrate, the process of transmitting the vibration source at the distal end to the grinding head through the transmission shaft is omitted, and the rotary grinding and the ultrasonic vibration are effectively and reasonably combined to grind the calcified tissue by a dual action.SELECTED DRAWING: Figure 16

Description

[Technical Field]

[0001] The present invention relates to the field of medical grinding equipment, and more particularly to an intravascular ultrasonic vibration assisted rotary grinding device. [Background technology]

[0002] Calcified tissue is a harmful substance formed by the deposition of fat, blood clots, connective tissue, and calcium carbonate on the inner walls of arteries. Treatment typically involves percutaneous coronary intervention (PCI). Percutaneous coronary intervention (PCI) is a minimally invasive interventional treatment that uses transcardial catheterization to clear blockages in the arterial lumen. It employs percutaneous puncture technology to deliver a dilating balloon or rotary abrasive instrument through the artery to dilate the lumen and modify some of the calcified tissue, thereby improving blood flow to the myocardium. PCI treatment methods primarily include percutaneous transluminal angioplasty (PTA), rotary abrasion (RA), and stent placement. Rotary abrasion is a typical internal abrasive removal process for lesion removal. It utilizes a rough-surfaced microcutter (olive-shaped with tiny diamond particles attached to its surface). Clinical approaches include the femoral and radial artery approaches. During the rotary abrasion procedure, a guide wire is used as a guide instrument, and first, the guide wire must be moved to its distal end so as to pass through the calcified tissue in order to more accurately identify the lesion site. Then, a rotary abrasion cutter is advanced along the guide wire to the proximal end of the calcified tissue, and the flexible transmission shaft drives the high-speed rotation of the cutter, pushing it back and forth in a "pecking" motion until it passes through the lesion site.

[0003] A Chinese patent application (publication number CN116807568A) discloses a multifunctional composite surgical device and application suitable for removing cardiovascular calcified tissue, which combines rotary grinding and ultrasonic vibration technology, and controls the rotary grinding cutter to reciprocate frequently over a small range during rotary grinding, thereby reducing the degree of interaction between the cutter and calcified tissue and achieving the goal of reducing the probability of the rotary grinding cutter becoming stuck. An ultrasonic element is installed at the position of the rotary grinding cutter to enable ultrasonic imaging. The ultrasonic vibration module used is located inside the operating handle outside the body, and the flexible transmission shaft can only transmit reciprocating vibration motion along the axial direction and cannot generate auxiliary vibrations in other directions, which makes it difficult to effectively apply the vibration effect to the location of the calcified tissue. The unidirectional vibration affects the rotary grinding effect on the calcified tissue. In addition, because the vibration source is far from the rotary grinding cutter, there is a large vibration loss during the transmission process. Increasing the parameters related to the vibration source makes it difficult to control the working position of the rotary grinding cutter at the end, which affects the operating accuracy of the rotary grinding process. Summary of the Invention

[0004] The present invention addresses the deficiencies of the prior art by providing an intravascular ultrasonic vibration-assisted rotary grinding device in which an ultrasonic transducer is fitted inside the grinding head, so that the vibration from the ultrasonic transducer can directly drive the vibration of the grinding head, eliminating the process of transmitting the vibration from the vibration source at the distal end to the grinding head via a transmission shaft, and grinding calcified tissue through the dual action of rotary grinding and ultrasonic vibration, thereby increasing the controllability during the vibration grinding operation and improving the accuracy of vibration grinding.

[0005] In order to solve the above-mentioned problems, the present invention employs the following solutions.

[0006] a grinding head having one end connected to a revolving flexible drive shaft and the other end used as a rotary grinding part, with an ultrasonic transducer fitted and fixed in a side wall between the two ends, and a lead wire of the ultrasonic transducer connected to an ultrasonic generator along the flexible drive shaft; a catheter mounted on the exterior of the flexible drive shaft and configured to rotate in engagement with the flexible drive shaft; a guide wire passing through the flexible drive shaft and the grinding head in this order along the axial direction, forming a rotating and sliding connection with the flexible drive shaft and a rotating and sliding connection with the grinding head; Intravascular ultrasonic vibration-assisted rotary grinding device.

[0007] Furthermore, the ultrasonic transducer is two fan-shaped piezoelectric ceramic sheets, which are distributed symmetrically with respect to the axis of the grinding head, and the piezoelectric ceramic sheets are curved to form tapered surfaces.

[0008] Furthermore, two symmetrically spaced apart mounting grooves are provided on the side wall between both ends of the grinding head, the piezoelectric ceramic sheet is fitted and fixed in the mounting grooves, and the openings of the mounting grooves are sealed with a filler.

[0009] Furthermore, the grinding head and the flexible drive shaft are provided with lead wire passages that are continuously distributed within the grinding head and the flexible drive shaft, and the lead wires pass through the lead wire passages before being drawn out of the flexible drive shaft.

[0010] Furthermore, the leads are connected to the ultrasonic generator via a conductive slip ring, and the lead passage is spaced apart from the distribution location of the guide wire.

[0011] Furthermore, guide wire passages distributed along the axial direction are provided within the grinding head and drive shaft, and the guide wire is configured to pass through the guide wire passage, and one end of the guide wire can be pulled out of the guide wire passage or retracted into the guide wire passage.

[0012] Furthermore, a debris discharge passage is provided within the tube wall of the catheter, and the debris discharge passage has an inlet provided in the outer wall of the catheter and an open outlet.

[0013] Furthermore, a retaining ring is provided on the outside of the catheter. The retaining ring has a tapered surface shape and is located between the inlet and outlet of the debris discharge passage, and the outer ring of the retaining ring is closer to the grinding head than the end of the retaining ring that is attached to the catheter.

[0014] Furthermore, the flexible drive shaft is a spring coil made of a wire wound in a spiral shape, and an anti-friction coating is provided on the outer wall of the flexible drive shaft.

[0015] Furthermore, a cooling passage is formed between the flexible drive shaft and the inner wall of the catheter for transporting a cooling fluid.

[0016] Compared with the prior art, the present invention has the following advantages and positive effects:

[0017] (1) In response to the current problem of poor coupling between vibration and grinding effects during rotary grinding of calcified tissues, an ultrasonic transducer is embedded inside the grinding head, allowing the vibrations from the ultrasonic transducer to directly drive the vibrations of the grinding head, eliminating the process of transmitting the vibration source at the distal end to the grinding head via the transmission shaft. Calcified tissues are ground through a dual action that effectively and rationally combines rotary grinding and ultrasonic vibration, improving controllability during the vibration grinding operation and increasing the accuracy of vibration grinding.

[0018] (2) The grinding head is designed to have an ultrasonic transducer attached inside, and a piezoelectric ceramic sheet is fitted and fixed inside the grinding head as an ultrasonic transducer. The piezoelectric ceramic sheet generates two-dimensional high-frequency ultrasonic vibrations, causing the grinding head to form an elliptical movement trajectory. The dual action of rotary grinding and ultrasonic vibrations increases the grinding efficiency for calcified tissue.

[0019] (3) The grinding head selectively removes fibrotic or calcified atherosclerotic plaque through "differential rotary grinding," while naturally ejecting elastic vascular tissue as the high-speed vibrating grinding head passes through. This reduces contact between the grinding head and elastic tissue and normal vascular walls, thereby increasing the safety of the rotary grinding process and protecting healthy tissue.

[0020] (4) The orientation of the piezoelectric ceramic sheet installed in the mounting groove can be changed according to needs. The piezoelectric ceramic sheet is arranged to form a predetermined angle with the axis of the grinding head. Different angles formed between the two piezoelectric ceramic sheets can generate different two-dimensional ultrasonic high-frequency vibrations, and even different composite vibration directions. This changes the movement trajectory of the abrasive grains relative to the calcified tissue during the grinding head's rotational grinding. Furthermore, before rotational grinding, the angle of the piezoelectric ceramic sheet can be adjusted according to different calcification conditions to select an appropriate movement trajectory and improve grinding efficiency.

[0021] (5) An inlet for a debris discharge passage is located on the outer peripheral surface of the proximal end of the catheter near the grinding head, and a debris discharge passage is provided inside the catheter, so that the shavings and coolant from the grinding area that are sucked in at the inlet position can be discharged to the outside of the catheter and withdrawn from the body, creating a circulation of the coolant, effectively reducing the temperature of the grinding area and effectively preventing the accumulation of shavings from affecting grinding efficiency.

[0022] The drawings in the specification that form a part of this invention are intended to provide a further understanding of the invention, and the illustrative embodiments of the invention and their descriptions are intended to interpret the invention and are not intended to unduly limit the invention. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a schematic diagram of an intravascular ultrasonic vibration-assisted rotary grinding device according to a first embodiment of the present invention. [Figure 2] 1 is a structural diagram of a grinding head according to a first embodiment of the present invention. [Figure 3] 1 is a schematic full cross-sectional view of a grinding head according to a first embodiment of the present invention. [Figure 4] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 5] 3 is a schematic diagram showing the distribution of ultrasonic transducers inside a grinding head in Example 1 of the present invention. FIG. [Figure 6] 3 is a structural schematic diagram of an ultrasonic transducer inside a grinding head in Example 1 of the present invention. FIG. [Figure 7] 1 is a schematic diagram of a wire wound around the outside of a drive shaft in Example 1 of the present invention. FIG. [Figure 8] FIG. 2 is a cross-sectional view of a drive shaft according to the first embodiment of the present invention. [Figure 9] FIG. 1 is a structural schematic diagram of a catheter according to a first embodiment of the present invention. [Figure 10] FIG. 1 is a cross-sectional schematic view of a catheter according to a first embodiment of the present invention. [Figure 11] 1 is a schematic radial cross-sectional view of a catheter according to a first embodiment of the present invention. [Figure 12] FIG. 2 is a schematic radial cross-sectional view of the catheter according to the first embodiment of the present invention at another axial position. [Figure 13] FIG. 2 is a structural schematic diagram of a retaining ring and a catheter according to the first embodiment of the present invention. [Figure 14] FIG. 2 is a cross-sectional view of a catheter and a retaining ring according to the first embodiment of the present invention. [Figure 15] 2 is a structural schematic diagram showing angles formed by ultrasonic transducers in Example 1 of the present invention. FIG. [Figure 16] 1 is a schematic diagram illustrating an operating state of the intravascular ultrasonic vibration-assisted rotary grinding device according to the first embodiment of the present invention; [Figure 17] 1 is a schematic diagram illustrating an operating state of the intravascular ultrasonic vibration-assisted rotary grinding device according to the first embodiment of the present invention; [Figure 18]1 is a flowchart of a manufacturing process of a grinding head according to a first embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] Example 1 In one exemplary embodiment of the present invention, an intravascular ultrasonic vibration assisted rotary grinding device is provided, as shown in FIGS.

[0025] When removing calcified tissues from blood vessels (7), conventional rotary grinding and rotary resection techniques use ultrasonic vibrations to enhance the removal effect. However, the poor coupling between the vibrations and rotary grinding results in poor removal efficiency, making it difficult to effectively grind away completely blocked calcified lesions. Based on this, this embodiment provides a two-dimensional ultrasonic vibration-assisted rotary grinding device for blood vessels (7). The grinding head (4) functions as both a rotary grinding workpiece and a carrier for the ultrasonic transducer (10) that generates vibrations. Driven by a rotating flexible drive shaft (8), the device performs high-speed rotary grinding. The ultrasonic transducer (10) inserted inside generates two-dimensional high-frequency ultrasonic vibrations when excited, allowing it to remove partially or completely blocked calcified tissues and thick superficial calcified rings.

[0026] Calcified tissue is ground away by the dual action of high-speed rotary grinding and high-frequency ultrasonic vibration, and healthy tissue such as the elastic walls of blood vessels 7 is repelled when it comes into contact with the grinding head 4 vibrating at high speed, ensuring that the rotary grinding acts safely on the calcified areas, improving the efficiency and safety of calcified tissue removal by rotary grinding.

[0027] 1 , the intravascular two-dimensional ultrasonic vibration-assisted rotary grinding device (7) mainly includes a grinding head (4), a catheter (6), a guidewire (1), and a control assembly. One end of the grinding head (4) is connected to a swivel flexible drive shaft (8), and the other end is used as a rotary grinding unit. The flexible drive shaft (8) can be connected to a swivel drive element of the control assembly, which drives the rotation of the flexible drive shaft (8) and the grinding head (4), thereby satisfying the need for performing rotary grinding. An ultrasonic transducer (10) is fitted and fixed in the side wall between both ends of the grinding head (4). A lead wire (11) of the ultrasonic transducer (10) is connected along the flexible drive shaft (8) to an ultrasonic generator (21) of the control assembly. The ultrasonic generator (21) transmits an electrical signal via the lead wire (11), exciting the ultrasonic transducer (10) to generate vibrations that act on the grinding head (4), causing the grinding head (4) to perform rotary grinding by orbiting. The catheter 6 is disposed outside the flexible drive shaft 8 and forms a rotational engagement with the flexible drive shaft 8, separating the rotating flexible drive shaft 8 from tissues such as blood vessels 7 outside the catheter 6, thereby preventing the flexible drive shaft 8 from coming into direct contact with external tissues. The guide wire 1 passes through the flexible drive shaft 8 and grinding head 4 in this order along its axial direction, thereby exerting a guiding effect. The guide wire 1 forms a rotational and sliding connection with the flexible drive shaft 8, thereby maintaining a guiding effect when the flexible drive shaft 8 rotates. Furthermore, the guide wire 1 forms a rotational and sliding connection with the grinding head 4, thereby satisfying the need for relative rotation and adjustment of the direction during operation of the grinding head 4.

[0028] As shown in Figure 2, guidewire 1 includes guidewire core 14 and a soft silicone protective sheath covering the tip of guidewire core 14 to prevent guidewire 1 from damaging the inner wall of blood vessel 7. Grinding head 4 consists of a rotating grinding portion and a smooth grinding head surface 3. One end of grinding head 4 acts on calcified tissue as the rotating grinding portion, while the other end is the smooth grinding head surface 3. The smooth grinding head surface 3 is connected to a flexible drive shaft 8, which transmits the rotational torque from the flexible drive shaft 8. The base material of grinding head 4 is tungsten carbide and has an olive shape. During operation, the rotating grinding portion is located in the front half of grinding head 4, at the end away from the flexible drive shaft 8. Diamond abrasive grains 2 are uniformly distributed on the rotating grinding portion.

[0029] It can be understood that the abrasive grains 2 distributed on the rotary grinding part can be particles other than diamond, for example, metal particles can be used as the abrasive grains 2. The rotary grinding part used for rotary grinding operation in the grinding head 4 is electroplated by ultrasonic sand embedding method, which ensures uniform plating of the abrasive grains 2 on the surface of the grinding head 4, and improves the efficiency and safety of grinding.

[0030] As shown in FIG. 3, the ultrasonic transducer 10 is composed of two fan-shaped piezoelectric ceramic sheets, which are symmetrically arranged about the axis of the grinding head 4 and are curved to form tapered surfaces, circumferentially arranged around the axis of the grinding head 4. The sidewall between both ends of the grinding head 4 is provided with two symmetrically spaced mounting grooves. The isolation structure between the two mounting grooves ensures the strength of the grinding head 4. The piezoelectric ceramic sheets are inserted and fixed into the mounting grooves, and the openings of the mounting grooves are filled with a filler, ensuring the strength of the grinding head 4 after the piezoelectric ceramic sheets are inserted and reducing the impact of the mounting grooves on the structural strength of the grinding head 4. Referring to FIG. 15, the angle between the symmetrically positioned meridians of the two piezoelectric ceramic sheets is α, which satisfies the following relationship: 0°≦α≦180°.

[0031] As shown in Figures 4 and 5, the ultrasonic transducer 10 is made of two piezoelectric ceramic sheets, and is fitted into the grinding head 4 and fixed inside the grinding head 4 by screws 19, the shape of which is shown in Figures 4 and 5. The grinding head 4 has screw holes 20 that fit the screws 19, and the piezoelectric ceramic sheets are fixed inside the grinding head 4 by the screws 19 to ensure the stability of the rotary grinding. After the piezoelectric ceramic sheets are fixed by the screws 19, a removable insulating filler is filled into the mounting groove that accommodates the ultrasonic transducer 10 to cover the mounting positions of the screws 19, and the entire surface of the grinding head 4 is covered with an insulating waterproof coating.

[0032] To drive the piezoelectric ceramic sheet, a series of lead wire passages are provided within the grinding head 4 and the flexible drive shaft 8. The lead wires 11 pass through the lead wire passages and are then drawn out of the flexible drive shaft 8. The lead wires 11 transmit the electrical signals output by the ultrasonic generator 21 to the piezoelectric ceramic sheet, thereby exciting the piezoelectric ceramic sheet. Referring to FIG. 3 , one end of the lead wire 11 for transmitting ultrasonic signals is connected to the ultrasonic transducer 10, and the other end is connected to the ultrasonic generator 21 outside the catheter 6. The lead wire 11 transmits high-frequency ultrasonic electrical signals to the ultrasonic transducer 10, thereby exciting the ultrasonic transducer 10 and generating two-dimensional high-frequency ultrasonic vibrations that act on the grinding head 4.

[0033] 5 and 6, the piezoelectric ceramic sheet and metal vibrating sheet 18 work together, with the piezoelectric ceramic sheet located above the metal vibrating sheet 18 and connected and fixed with an adhesive such as epoxy resin, and electrode wires 15 are uniformly distributed on the piezoelectric ceramic sheet, and one end of the lead wire 11 is fixedly attached and connected to an electrode sheet 16 on the piezoelectric ceramic sheet by soldering, thereby realizing signal transmission. In addition, the piezoelectric ceramic sheet and metal vibrating sheet 18 are covered with an insulating coating.

[0034] As shown in FIG. 7 , the flexible drive shaft 8 is a spring coil formed by spirally winding a wire 13, and the outer wall of the flexible drive shaft 8 is provided with an anti-friction coating. In this embodiment, the flexible drive shaft 8 is a flexible power transmission shaft that transmits torque around its axis and is bendable to transmit non-coaxial rotation from one end to the other. The flexible drive shaft 8 is a spring coil formed by spirally winding one or more wires 13, and a guidewire passage is formed inside the flexible drive shaft 8 through which the guidewire core 14 passes, providing high torque and flexibility. The inner and outer surfaces of the flexible drive shaft 8 are coated with a low-friction coating, such as a PTFE polymer coating, which reduces friction between the inner surface of the flexible drive shaft 8 and the guidewire 1, reduces friction between the outer surface of the flexible drive shaft 8 and the inner wall of the catheter 6, and further reduces frictional heat.

[0035] As shown in Figure 8, the grinding head 4 and the flexible drive shaft 8 have continuously distributed lead wire passages, and the lead wires 11 pass through the lead wire passages before being drawn out of the flexible drive shaft 8. The grinding head 4 and the flexible drive shaft 8 can be connected by laser welding, and a vibration damping gasket 12 is further provided at the connection point between the grinding head 4 and the flexible drive shaft 8 to reduce the transmission of vibrations of the grinding head 4 along the flexible drive shaft 8 and ensure stable rotation of the flexible drive shaft. The lead wire passages through which the lead wires 11 transmitting ultrasonic signals pass are distributed within the side walls of the spring coils corresponding to the flexible drive shaft 8.

[0036] In order to achieve motion decoupling between the rotation of the flexible drive shaft 8 and the connection of the lead wire 11 to the ultrasonic generator 21, the lead wire 11 is connected to the ultrasonic generator 21 via a conductive slip ring, so that the lead wire 11 can be connected to the ultrasonic generator 21 even when the flexible drive shaft 8 is rotating; a structure such as a gear or worm wheel can be attached to the outside of the flexible drive shaft 8, and rotation is achieved by driving the external gear or worm, satisfying the rotation demand of the flexible drive shaft 8; and the distribution positions of the lead wire passage and the guide wire 1 are separated, so interference between the guide wire 1 and the lead wire 11 is avoided.

[0037] Guide wire passages distributed along the axial direction are provided within the grinding head 4 and the drive shaft, and the guide wire 1 is arranged to pass through the guide wire passage, with one end of the guide wire 1 being able to be pulled out of the guide wire passage or retracted into the guide wire passage.

[0038] 9, the catheter 6 may be a PVC hose or other hose materials that meet the requirements of medical procedures. The catheter 6 is a hollow tube with a passageway in the center.

[0039] Furthermore, while prior art laser calcification ablation devices can reduce the volume of calcified tissue after destruction by removing calcified areas with a short-range pulsed laser, it is difficult to dispose of the calcified debris generated by the rotary grinding process. Based on this, in this embodiment, as shown in Figures 10 and 11, a debris discharge passage is provided within the catheter tube wall 17, with an inlet provided on the outer wall of the catheter 6 and an open outlet.

[0040] As shown in Figure 12, a cooling passage 9 for transporting a cooling liquid is formed between the flexible drive shaft 8 and the inner wall of the catheter 6. The cooling passage 9 may also be used to transport a medicinal liquid. The cooling liquid is pumped out from one end of the catheter 6 close to the grinding head 4, thereby achieving the effects of removing shavings on the grinding head 4 and reducing the temperature of the rotary grinding work area.

[0041] The cooling liquid is discharged through one end of the catheter 6 close to the grinding head 4. In order to prevent the cooling liquid from being extracted by the debris discharge passage when it is not acting on the rotary grinding position after being discharged, the debris discharge inlet is provided on the outer wall of the catheter 6 and is spaced apart from the one end of the catheter 6 close to the grinding head 4. The debris discharge inlet and the position from which the cooling liquid is discharged in the cooling passage 9 are separated from each other to enhance the cooling effect. A one-way flow path is formed between the cooling liquid discharge position, the rotary grinding operation position, and the debris discharge inlet, thereby enhancing the cooling effect and the debris discharge effect.

[0042] When the coolant acts on the rotary grinding position, the grinding chips at the grinding head 4 are drawn in by the inlet of the chip discharge passage and then drawn out of the body through the outlet of the chip discharge passage, thereby reducing the amount of chips accumulated in the blood vessel 7. It can be understood that a suction member such as a suction assembly can be connected to the outlet of the chip discharge passage, which can easily create negative pressure in the chip discharge passage and realize the process of the grinding chips being entrained in the coolant and discharged, thereby reducing secondary damage to the human body caused by the blockage of the blood vessel 7 due to the accumulation of a large amount of chips.

[0043] As shown in Figures 13 and 14, a retaining ring 5 is provided on the outside of the catheter 6 to increase the amount of shavings passing through the passage. The retaining ring 5 has a tapered surface and is located between the entrance and exit of the shavings discharge passage. The outer ring of the retaining ring 5 is closer to the grinding head 4 than the end of the retaining ring 5 that is attached to the catheter 6. A flexible retaining ring 5 as shown in Figure 1 is provided on the outer surface of the catheter 6. The retaining ring 5 has a tapered surface and is configured as a horn-shaped structure, with the larger diameter side of the horn-shaped structure facing the rotational grinding position. As shown in Figures 16 and 17, the impact of the coolant causes the shavings to flow back along the catheter 6, i.e., toward the ultrasonic generator 21 outside the body. The retaining ring 5 blocks the movement path of the coolant and shavings that have finished washing them away. At this time, the coolant carries the shavings along the retaining ring 5 to the entrance of the shavings discharge passage and is discharged along the shavings discharge passage to the outside of the body, increasing the amount of shavings discharged.

[0044] It can be understood that when rotary grinding is performed on calcified tissue, if the temperature in the rotary grinding area is too high or rises too quickly, the flow rate of the coolant can be increased, which will speed up the temperature drop and increase the amount of shavings discharged through the debris discharge passage, thereby improving the cooling effect. The flexible retaining ring 5 can be made of the same material as the catheter 6, and can be integrally molded during the processing of the catheter 6, or the retaining ring 5 and the catheter 6 can be connected by adhesive in a subsequent process.

[0045] 1, the grinding head 4 is connected to the drive shaft control assembly and one end remote from the ultrasonic generator 21, and the guide wire 1 is arranged to pass through the grinding head 4 and the drive shaft, and the drive shaft and grinding head 4 are movable along the axial direction of the guide wire 1 and are also capable of rotating around the guide wire 1. When performing rotary grinding, the grinding head 4 can be moved back and forth by operating the guide wire 1 and the drive shaft. Here, moving along the axial direction means moving along the axial direction of the guide wire 1 toward or away from the ultrasonic generator 21, thereby performing rotary grinding on the portion of the blood vessel 7 that requires rotary grinding to remove blockages in the lumen.

[0046] When grinding heavily or completely calcified blood vessels 7, the diamond abrasive grains 2 at the tip of the grinding head 4 first grind away the calcified tissue, while the lead wire 11 transmits an extracorporeal ultrasonic electrical signal to the ultrasonic transducer 10, causing the ultrasonic transducer 10 to generate high-frequency ultrasonic vibrations. The calcified tissue is more easily removed by the dual action of the diamond abrasive grains 2 and the ultrasonic vibrations, after which the grinding head 4 and the entire catheter 6 can be driven into position for subsequent treatment.

[0047] As shown in FIG. 18, the processing process of the grinding head 4 includes shaping the grinding head 4 and electroplating the grinding head 4.

[0048] The grinding head 4 is shaped as follows: The bar material of the grinding head 4 is turned into an ellipsoid by turning; the portion to be fitted into the ultrasonic transducer 10 is machined by milling; the passages for the lead wire 11 and the guide wire 1 are machined by drilling, and the lead wire passage and the guide wire passage are obtained accordingly.

[0049] The electroplating process of the grinding head 4 mainly includes cleaning the base of the grinding head 4 and pre-plating a nickel layer, preparing a diamond abrasive, and nickel-diamond codeposition. Cleaning the base of the grinding head 4 involves degreasing and cleaning the base of the grinding head 4 in an ultrasonic cleaner using alcohol or acetone reagent. Pre-plating nickel on the base of the grinding head 4 is carried out on a water bath heating test stand. Preparation of the diamond abrasive is carried out on an ultrasonic vibration test stand. Nickel-diamond codeposition is also carried out on an ultrasonic vibration test stand.

[0050] The nickel pre-plating on the surface of the grinding head 4 is carried out using a nickel block as the anode and the base of the grinding head 4 as the cathode under conditions of a current of 15 mA, a voltage of 0.8 to 1.1 V, and a temperature of 55°C, using a Watts bath containing nickel sulfamate, nickel chloride, boric acid, sodium dodecyl sulfate, and saccharin as the electroplating solution.

[0051] The process of preparing diamond abrasive grains 2 includes first putting the abrasive grains 2 into an alcohol or acetone solution to form a mixed solution, placing the mixed solution on an ultrasonic vibration test stand to perform ultrasonic vibration dispersion, collecting the upper layer liquid, and obtaining initial abrasive grains 2 by suction filtration, and then washing and drying the initial abrasive grains 2 to prepare the final abrasive grains 2.

[0052] The working process of the intravascular two-dimensional ultrasonic vibration assisted rotary grinding device is described as follows:

[0053] The guide wire 1 is inserted into an appropriate position in the artery close to the calcified lesion area, and the end of the guide wire 1 is covered with a soft material to prevent the guide wire 1 from damaging the inner wall of the blood vessel 7. Once the guide wire 1 reaches the predetermined position, the guide wire 1 is passed through the inside of a catheter 6 outside the body, and the catheter 6 is passed along the guide wire 1 to the calcified area. Then, the grinding head 4 and flexible drive shaft 8 are advanced via the catheter 6 and the guide wire 1, and the guide wire 1 is advanced through the calcified lesion to the distal end of the coronary artery. Then, the grinding head 4 and flexible drive shaft 8 are pushed along the guide wire 1 to the proximal end of the calcified lesion.

[0054] Once the grinding head 4 and catheter 6 reach the desired position, the rotating grinding console of the control assembly outside the body is adjusted to cause the flexible drive shaft 8 to rotate the grinding head 4 at high speed, and the ultrasonic generator 21 outside the body is adjusted to generate a high-frequency ultrasonic electrical signal, which is transmitted via lead wire 11 to the ultrasonic transducer 10 fitted inside the grinding head 4, thereby converting the high-frequency ultrasonic electrical signal into high-frequency ultrasonic vibrations.

[0055] The ultrasonic transducer 10 generates two-dimensional high-frequency ultrasonic vibrations by fixing two piezoelectric ceramic sheets at a certain angle inside the grinding head 4. In addition, a vibration damping gasket 12 is installed at the connection between the grinding head 4 and the flexible drive shaft 8 to effectively reduce the impact of vibrations from the grinding head 4 on the flexible drive shaft 8. By selecting grinding heads 4 with different angles between the two piezoelectric ceramic sheets, different two-dimensional vibration trajectories can be generated to address the complex conditions of different calcified areas, thereby achieving different grinding effects and improving rotary grinding efficiency.

[0056] As shown in Figure 15, when two piezoelectric ceramic sheets are positioned on the same plane and perpendicular to the axis of the grinding head 4, the ultrasonic vibrations from the piezoelectric ceramic sheets are in the same direction and overlap the central axis of the grinding head 4. At this time, the abrasive grains 2 of the grinding head 4 form a linear reciprocating motion locus parallel to the axis relative to the calcified tissue. When two piezoelectric ceramic sheets are positioned parallel to the axis of the grinding head 4 and overlap, the ultrasonic vibrations from the piezoelectric ceramic sheets are perpendicular to the central axis of the grinding head 4. At this time, the abrasive grains 2 of the grinding head 4 form a linear reciprocating motion locus perpendicular to the axis relative to the calcified tissue. When the two piezoelectric ceramic sheets are positioned between these two states, the abrasive grains 2 of the grinding head 4 form an elliptical motion locus relative to the calcified tissue. The distribution of the piezoelectric ceramic sheets can be configured as needed.

[0057] To achieve the goal of lowering the temperature of the grinding area while the grinding head 4 is operating, saline is transported as a coolant from outside the body along the cooling passage 9 to the position of the grinding head 4. If the temperature of the grinding area is high, the temperature can be reduced more quickly by increasing the flow rate of the saline. The saline not only reduces the temperature but also washes away the shavings from the grinding head 4. The washed-out shavings and saline flow to the entrance of the shavings discharge passage due to the difference in liquid pressure in the grinding area and are then discharged outside the body through the shavings discharge passage. The retaining ring 5 on the outside of the catheter 6 serves to block and guide the washed-out shavings and saline.

[0058] During rotary grinding, the grinding head 4 with the diamond abrasive grains 2 can be retracted to the proximal end of the lesion, and rotary grinding is repeated until resistance disappears and the grinding head 4 is pushed and retracted until the calcified lesion is removed. After rotary grinding is completed, the external rotary grinding console and ultrasonic generator 21 are turned off to stop the rotation and vibration of the grinding head 4, and the grinding head 4, flexible drive shaft 8, and catheter 6 are removed outside the body along the guide wire 1, after which the guide wire 1 is removed outside the body and the device is disinfected.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art can make various modifications and changes to the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. [Explanation of symbols]

[0060] 1 Guidewire 2 abrasive grains 3. Smooth surface of grinding head 4 grinding heads 5 Retaining ring 6 Catheters 7 blood vessels 8 Flexible drive shaft 9 Cooling passage 10 Ultrasonic Transducer 11 Lead wire 12 Vibration damping gasket 13 Wire rod 14 Guidewire core 15 Electrode wire 16 Electrode sheet 17 Catheter wall 18 Metal Vibrating Sheet 19 screws 20 screw holes 21 Ultrasonic generator

Claims

1. a grinding head having one end connected to a revolving flexible drive shaft and the other end used as a rotary grinding part, with an ultrasonic transducer fitted and fixed in a side wall between the two ends, and a lead wire of the ultrasonic transducer connected to an ultrasonic generator along the flexible drive shaft; a catheter mounted on the exterior of the flexible drive shaft and configured to rotate in engagement with the flexible drive shaft; a guide wire passing through the flexible drive shaft and the grinding head in this order along an axial direction, and forming a rotating and sliding connection with the flexible drive shaft and a rotating and sliding connection with the grinding head; The ultrasonic transducer is two fan-shaped piezoelectric ceramic sheets, which are symmetrically distributed with respect to the axis of the grinding head, and the piezoelectric ceramic sheets are curved to form tapered surfaces. An intravascular ultrasonic vibration-assisted rotary grinding device.

2. 2. The intravascular ultrasonic vibration-assisted rotary grinding device according to claim 1, characterized in that the side wall between both ends of the grinding head is provided with two mounting grooves that are symmetrically spaced apart, the piezoelectric ceramic sheet is inserted and fixed into the mounting grooves, and the openings of the mounting grooves are sealed with a filler.

3. 2. The intravascular ultrasonic vibration-assisted rotary grinding device according to claim 1, wherein the grinding head and the flexible drive shaft are provided with a continuous lead wire passage, and the lead wire passes through the lead wire passage and is then drawn out of the flexible drive shaft.

4. The intravascular ultrasonic vibration-assisted rotary grinding device according to claim 3, characterized in that the lead wire is connected to the ultrasonic generator via a conductive slip ring, and the lead wire passage is spaced apart from the distribution position of the guide wire.

5. The intravascular ultrasonic vibration-assisted rotary grinding device of claim 1, characterized in that the grinding head and the drive shaft are provided with guide wire passages distributed along the axial direction, the guide wire is arranged to pass through the guide wire passages, and one end of the guide wire can be pulled out of the guide wire passage or retracted into the guide wire passage.

6. 2. The intravascular ultrasonic vibration-assisted rotary grinding device according to claim 1, wherein a debris discharge passage is provided in the tubular wall of the catheter, the inlet of the debris discharge passage being provided on the outer wall of the catheter and the outlet being open.

7. 7. The intravascular ultrasonic vibration-assisted rotary grinding device according to claim 6, wherein a retaining ring is provided on the outside of the catheter, the retaining ring having a tapered surface shape and located between the inlet and outlet of the debris discharge passage, and the outer ring of the retaining ring is closer to the grinding head than the end of the retaining ring that is attached to the catheter.

8. 2. The intravascular ultrasonic vibration-assisted rotary grinding device according to claim 1, wherein the flexible drive shaft is a spring coil made of a spirally wound wire, and an anti-friction coating is provided on the outer wall of the flexible drive shaft.

9. 10. The intravascular ultrasonic vibration assisted rotary grinding device according to claim 1 or 8, wherein a cooling passage for transporting a cooling liquid is formed between the flexible drive shaft and the inner wall of the catheter.

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