A cross plate screw piezoelectric drive puncture device and its working method
Patent Information
- Application Number
- CN202611303673.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-26
- Publication Date
- 2026-10-30
AI Technical Summary
1.电磁驱动受磁场干扰：传统电磁驱动内部线圈或永磁体易在MRI强磁场下失控或发热，同时产生图像伪影，难以保证穿刺精度和操作安全
（1）本发明电磁兼容性好，不仅不受电磁的干扰，而且不产生磁场，可以不受MRI环境的影响，同时不会对MRI成像质量产生影响；
Smart Images
Figure CN122997795A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of high-end medical devices, minimally invasive techniques, robots, and precision drive technologies, specifically to a cross-plate screw-type piezoelectric drive puncture device and its working method. Background Technology
[0002] Magnetic resonance imaging (MRI)-guided trocars are the core actuators for achieving precise interventional diagnosis and treatment, widely used in minimally invasive surgeries such as biopsy, deep brain stimulation (DBS), tumor ablation, targeted drug delivery, and nerve blocks. Leveraging MRI's superior soft tissue resolution and real-time imaging capabilities, the trocar can precisely navigate the needle to the target lesion. Its performance directly determines the accuracy of the puncture, surgical efficiency, and the quality of postoperative recovery for the patient. In an MRI environment, the trocar must meet stringent requirements: firstly, it must possess excellent MRI compatibility; its materials and structure should not produce image artifacts under strong magnetic fields, and its internal moving parts must not malfunction or interfere due to electromagnetic induction; secondly, it must achieve precise needle insertion control to reduce puncture resistance and tissue damage; and thirdly, it must possess high precision, fast response, and high stability.
[0003] Current MRI-compatible trocars mainly employ electromagnetic, hydraulic, pneumatic, or piezoelectric drive technologies, but they have significant shortcomings: 1. Electromagnetic drive is susceptible to magnetic field interference: The internal coils or permanent magnets of traditional electromagnetic drives are prone to runaway or overheating under the strong magnetic field of MRI, while also producing image artifacts, making it difficult to guarantee puncture accuracy and operational safety. Although remote hydraulic or pneumatic transmission can avoid magnetic interference, the long tubing brings response lag, reduced accuracy, and the risk of failure.
[0004] 2. The piezoelectric drive is heavily assembled: Most existing piezoelectric drives rely on direct assembly of commercial piezoelectric motors or ultrasonic motors. The drive mechanism is separated from the transmission and the end puncture needle, resulting in large size, poor rigidity, low energy transfer efficiency, and difficulty in ensuring the stability and repeatability of the action.
[0005] 3. Low structural integration: The separate design of the drive, transmission and puncture needle modules results in significant mechanical gaps and hysteresis, which limits the accuracy, stability and long-term reliability of minimally invasive procedures.
[0006] 4. Insufficient compound motion capability: Traditional trocars are mostly single-axis needle insertion or simple rotational motion, which cannot achieve rotation-linear compound needle insertion motion. Macroscopic errors are easily transmitted to the target point, making it difficult to balance accuracy and low tissue damage.
[0007] 5. Insufficient dynamic response and stability: Existing mechanical or pneumatic-hydraulic driven puncture devices have problems with slow response and uneven output in micro-operations, making it difficult to meet the requirements of real-time dynamic control and high-precision minimally invasive operations.
[0008] To address the aforementioned technical bottlenecks, this invention proposes an MRI-compatible cross-plate screw-type piezoelectric-driven puncture device. Through integrated piezoelectric drive design, it achieves structural and functional integration, generating a twisting-lifting-insertion compound needle insertion motion. It also features MRI compatibility, high precision, rapid response, low tissue damage, and high stability, and can be widely applied in minimally invasive puncture procedures such as neurointervention, deep brain electrode implantation, tumor targeted injection, biopsy, drug delivery, and scientific research experiments. Summary of the Invention
[0009] The technical problem to be solved by the present invention is to address the deficiencies mentioned in the background art by providing a cross-shaped plate screw type piezoelectric driven puncture device and its working method.
[0010] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: An MRI-compatible cross-plate screw-type piezoelectrically driven trocar includes a base, a clamping plate, a cross-shaped plate threaded stator, dual rotors, a Luer connector, and a medical trocar needle; The cross-shaped plate threaded stator includes a metal matrix, a hollow screw, first to fourth lugs, and first to eighth piezoelectric ceramic plates; The metal substrate is a cross-shaped metal plate with central symmetry, including a central plate and first to fourth side plates. The central plate is square, and the first to fourth side plates are rectangles of the same shape. The short side length of the first to fourth side plates is equal to the side length of the central plate, and the short side of the first to fourth side plates is fixedly connected to the four sides of the central plate respectively. The first to fourth ear pieces are respectively fixed to the ends of the first to fourth side plates away from the center plate, and are all coplanar with the metal substrate; One end of the hollow screw is perpendicularly fixed to the center of one end face of the center plate, and the center plate is provided with a through hole along its axis with the same diameter as the inner diameter of the hollow screw; The first to eighth piezoelectric ceramic sheets are all rectangular piezoelectric ceramic sheets with the same structure and polarization along the thickness direction. The first to fourth piezoelectric ceramic sheets are attached to the center of the end face of the first to fourth side plates and the hollow screw on the same side in a clockwise direction. The fifth to eighth piezoelectric ceramic sheets are attached to the center of the other end face of the first to fourth side plates respectively. The first to fourth piezoelectric ceramic sheets and the fifth to eighth piezoelectric ceramic sheets are symmetrically corresponding to each other. The long side of the first to eighth piezoelectric ceramic sheets is parallel to the long side of the side plate on which they are located. The first, fourth, fifth, and eighth piezoelectric ceramic sheets have the same polarization direction. The second, third, sixth, and seventh piezoelectric ceramic sheets have the same polarization direction. The first and second piezoelectric ceramic sheets have opposite polarization directions. The lower end of the clamping plate is fixedly connected to the base, and a cross-shaped through hole is provided in the center for mating with the metal substrate; The first to fourth ear pieces are all fixedly connected to the clamping plate, so that the metal substrate is located in the cross-shaped through hole of the clamping plate, and the hollow screw and the center plate are coaxial. The dual rotors include a front rotor, a rear rotor, a threaded cylinder, first and second preload bolts, first and second preload springs, and first and second preload nuts; Both the front rotor and the rear rotor are annular in shape, and their inner walls are provided with internal threads for cooperating with the hollow screw. The rear rotor is symmetrically provided with two countersunk through holes that respectively cooperate with the first preload bolt and the second preload bolt; the front rotor is symmetrically provided with two through holes that respectively cooperate with the first preload bolt and the second preload bolt. Both the front rotor and the rear rotor are threadedly connected to the hollow screw, with a gap between them. The rear rotor is located between the front rotor and the clamping plate. The first preload bolt and the second preload bolt pass through the corresponding countersunk holes on the rear rotor and the corresponding through holes on the front rotor, respectively, and are threadedly connected to the first preload nut and the second preload nut. The first preload spring and the second preload spring are respectively fitted onto the studs of the first preload bolt and the second preload bolt, with one end abutting against the first preload nut and the second preload nut, respectively, and the other end abutting against the front rotor. The first and second preload bolts, the first and second preload springs, and the first and second preload nuts are used to provide preload. The threaded cylinder is a hollow cylinder with openings at both ends. Its inner wall is provided with internal threads for mating with the hollow screw, and its length is greater than the length of the hollow screw. One end of the threaded cylinder is coaxially and fixedly connected to the end of the front rotor away from the rear rotor, and the threaded cylinder and the hollow screw are threadedly connected. The threaded end of the Luer connector is threadedly connected to the end of the threaded cylinder away from the front rotor, and the tapered end is engaged with the male Luer tapered surface of the medical puncture needle.
[0011] As a further optimization of the MRI-compatible cross-plate screw-type piezoelectric driven puncture device of the present invention, one end face of the clamping plate is provided with first to fourth grooves for cooperating with the first to fourth lugs, and each of the first to fourth grooves is provided with through holes for cooperating with bolts. The other end face of the clamping plate is provided with fifth to eighth grooves corresponding to the first to fourth grooves. The first to fourth lugs are fixed to the clamping plate by four bolts and four nuts. The four bolts are located in the first to fourth grooves, and the four nuts are located in the fifth to eighth grooves.
[0012] This invention also discloses a method for operating the MRI-compatible cross-plate screw-type piezoelectrically driven trocar, comprising the following steps: If the puncture needle needs to complete tangential rotation and linear feed, a preset A-phase simple harmonic voltage signal is applied to the first, third, fifth, and seventh piezoelectric ceramic plates, and a preset B-phase simple harmonic voltage signal is applied to the second, fourth, sixth, and eighth piezoelectric ceramic plates. The B-phase simple harmonic voltage signal and the A-phase simple harmonic voltage signal have a 90° phase difference. At this time, the metal substrate generates two orthogonal second-order bending vibration deformations, which in turn induce two orthogonal bending vibrations on the hollow screw. The hollow screw is coupled into a positive-direction rotating "head-shaking" motion. The external thread friction on the screw drives the dual rotor motion, thus realizing the "twisting-insertion" motion of the puncture needle. If the puncture needle needs to complete reverse rotation and linear retraction, that is, to achieve the "twisting-lifting" movement of the puncture needle, the phase difference between the B-phase simple harmonic voltage signal and the A-phase simple harmonic voltage signal can be adjusted to -90°.
[0013] Compared with the prior art, the present invention, employing the above technical solution, has the following beneficial effects: (1) The present invention has good electromagnetic compatibility. It is not only unaffected by electromagnetic interference, but also does not generate a magnetic field. It is unaffected by the MRI environment and does not affect the MRI imaging quality. (2) The present invention has a highly integrated structure, with the drive and transmission integrated, which not only has a compact structure, but also high stability, high puncture accuracy and fast response; (3) The present invention adopts a dual-rotor structure, which can increase the contact area of the screw pair, improve the driving force and running stability, and utilize the synergistic cooperation of the dual rotors and the screw to form an integrated pre-pressure adjustment mechanism. This mechanism can achieve adjustable and stable pre-pressure without external assistance, and the overall structure is compact, making it particularly suitable for space-constrained environments; (4) In this invention, both the stator and the dual rotor of the piezoelectric drive puncture device are provided with coaxial through holes to form a hollow through channel. This structure reduces the mass of the moving parts and the moment of inertia, which is beneficial to improving the stator amplitude and high-frequency drive response performance. On the other hand, this channel can accommodate operations such as drug injection, tissue aspiration or guide wire passage during puncture, thereby expanding the clinical applicability of the device. (5) The present invention can realize the "twisting-lifting" combined motion of needle insertion, which can effectively reduce the tissue pushing effect, reduce stress concentration and force change, improve the accuracy, stability and controllability of the puncture process, and at the same time achieve low tissue damage puncture. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the cross-shaped plate threaded stator in this invention; Figure 3 This is a schematic diagram showing the polarization direction of the first to eighth piezoelectric ceramic sheets and the applied voltage signal in this invention; Figure 4 This is a schematic diagram of the dual rotor structure in this invention; Figure 5 This is a schematic diagram of the amplitude of the cross-shaped plate threaded stator in this invention; Figure 6 This is a schematic diagram of the working cycle of the cross-shaped plate threaded stator in this invention; In the figure, 1-base, 2-clamping plate, 3-cross-shaped plate threaded stator, 4-double rotor, 5-Luer connector, 6-medical puncture needle, 7-first ear plate, 8-second piezoelectric ceramic plate, 9-hollow screw, 10-metal substrate, 11-rear rotor, 12-front rotor, 13-first preload spring, 14-first preload nut, 15-first preload bolt, 16-threaded cylinder. Detailed Implementation
[0015] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings: This invention can be implemented in many different forms and should not be considered limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully express the scope of the invention to those skilled in the art. In the drawings, components are enlarged for clarity.
[0016] like Figure 1 As shown, an MRI-compatible cross-plate screw-type piezoelectrically driven trocar includes a base, a clamping plate, a cross-shaped plate threaded stator, dual rotors, a Luer connector, and a medical trocar needle. like Figure 2 As shown, the cross-shaped plate threaded stator includes a metal matrix, a hollow screw, first to fourth lugs, and first to eighth piezoelectric ceramic plates; The metal substrate is a cross-shaped metal plate with central symmetry, including a central plate and first to fourth side plates. The central plate is square, and the first to fourth side plates are rectangles of the same shape. The short side length of the first to fourth side plates is equal to the side length of the central plate, and the short side of the first to fourth side plates is fixedly connected to the four sides of the central plate respectively. The first to fourth ear pieces are respectively fixed to the ends of the first to fourth side plates away from the center plate, and are all coplanar with the metal substrate; One end of the hollow screw is perpendicularly fixed to the center of one end face of the center plate, and the center plate is provided with a through hole along its axis with the same diameter as the inner diameter of the hollow screw; like Figure 2 , Figure 3As shown, the first to eighth piezoelectric ceramic sheets are all rectangular piezoelectric ceramic sheets with the same structure and polarization along the thickness direction. The first to fourth piezoelectric ceramic sheets are attached to the center of the end face of the first to fourth side plates and the hollow screw on the same side in a clockwise direction. The fifth to eighth piezoelectric ceramic sheets are attached to the center of the other end face of the first to fourth side plates, and the first to fourth piezoelectric ceramic sheets and the fifth to eighth piezoelectric ceramic sheets are symmetrically corresponding to each other. The long side of the first to eighth piezoelectric ceramic sheets is parallel to the long side of the side plate on which they are located. The polarization direction of the first, fourth, fifth, and eighth piezoelectric ceramic sheets is the same, the polarization direction of the second, third, sixth, and seventh piezoelectric ceramic sheets is the same, and the polarization direction of the first and second piezoelectric ceramic sheets is opposite. The lower end of the clamping plate is fixedly connected to the base, and a cross-shaped through hole is provided in the center for mating with the metal substrate; The first to fourth ear pieces are all fixedly connected to the clamping plate, so that the metal substrate is located in the cross-shaped through hole of the clamping plate, and the hollow screw and the center plate are coaxial. like Figure 4 As shown, the dual rotors include a front rotor, a rear rotor, a threaded cylinder, first and second preload bolts, first and second preload springs, and first and second preload nuts; Both the front rotor and the rear rotor are annular in shape, and their inner walls are provided with internal threads for cooperating with the hollow screw. The rear rotor is symmetrically provided with two countersunk through holes that respectively cooperate with the first preload bolt and the second preload bolt; the front rotor is symmetrically provided with two through holes that respectively cooperate with the first preload bolt and the second preload bolt. Both the front rotor and the rear rotor are threadedly connected to the hollow screw, with a gap between them. The rear rotor is located between the front rotor and the clamping plate. The first preload bolt and the second preload bolt pass through the corresponding countersunk holes on the rear rotor and the corresponding through holes on the front rotor, respectively, and are threadedly connected to the first preload nut and the second preload nut. The first preload spring and the second preload spring are respectively fitted onto the studs of the first preload bolt and the second preload bolt, with one end abutting against the first preload nut and the second preload nut, respectively, and the other end abutting against the front rotor. The first and second preload bolts, the first and second preload springs, and the first and second preload nuts are used to provide preload. The threaded cylinder is a hollow cylinder with openings at both ends. Its inner wall is provided with internal threads for mating with the hollow screw, and its length is greater than the length of the hollow screw. One end of the threaded cylinder is coaxially and fixedly connected to the end of the front rotor away from the rear rotor, and the threaded cylinder and the hollow screw are threadedly connected. The threaded end of the Luer connector is threadedly connected to the end of the threaded cylinder away from the front rotor, and the tapered end is engaged with the male Luer tapered surface of the medical puncture needle.
[0017] As a further optimization of the MRI-compatible cross-plate screw-type piezoelectric driven puncture device of the present invention, one end face of the clamping plate is provided with first to fourth grooves for cooperating with the first to fourth lugs, and each of the first to fourth grooves is provided with through holes for cooperating with bolts. The other end face of the clamping plate is provided with fifth to eighth grooves corresponding to the first to fourth grooves. The first to fourth lugs are fixed to the clamping plate by four bolts and four nuts. The four bolts are located in the first to fourth grooves, and the four nuts are located in the fifth to eighth grooves.
[0018] like Figure 6 As shown, the present invention also discloses a method for operating the MRI-compatible cross-plate screw-type piezoelectrically driven trocar, comprising the following steps: If the puncture needle needs to complete tangential rotation and linear feed, a preset A-phase simple harmonic voltage signal is applied to the first, third, fifth, and seventh piezoelectric ceramic plates, and a preset B-phase simple harmonic voltage signal is applied to the second, fourth, sixth, and eighth piezoelectric ceramic plates. The B-phase simple harmonic voltage signal and the A-phase simple harmonic voltage signal have a 90° phase difference. At this time, the metal substrate generates two orthogonal second-order bending vibrations, which in turn induce two orthogonal bending vibrations on the hollow screw. These vibrations are coupled into a positive-direction rotating "head-shaking" motion on the hollow screw. Figure 5 As shown, the external thread on the screw drives the dual rotors to move, thus realizing the "twisting-insertion" motion of the puncture needle; If the puncture needle needs to complete reverse rotation and linear retraction, that is, to achieve the "twisting-lifting" movement of the puncture needle, the phase difference between the B-phase simple harmonic voltage signal and the A-phase simple harmonic voltage signal can be adjusted to -90°.
[0019] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.
[0020] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. An MRI-compatible cross-plate screw-type piezoelectrically driven trocar, characterized in that, Includes a base, clamping plate, cross-shaped threaded stator, dual rotor, Luer connector, and medical puncture needle; The cross-shaped plate threaded stator includes a metal matrix, a hollow screw, first to fourth lugs, and first to eighth piezoelectric ceramic plates; The metal substrate is a cross-shaped metal plate with central symmetry, including a central plate and first to fourth side plates. The central plate is square, and the first to fourth side plates are rectangles of the same shape. The short side length of the first to fourth side plates is equal to the side length of the central plate, and the short side of the first to fourth side plates is fixedly connected to the four sides of the central plate respectively. The first to fourth ear pieces are respectively fixed to the ends of the first to fourth side plates away from the center plate, and are all coplanar with the metal substrate; One end of the hollow screw is perpendicularly fixed to the center of one end face of the center plate, and the center plate is provided with a through hole along its axis with the same diameter as the inner diameter of the hollow screw; The first to eighth piezoelectric ceramic sheets are all rectangular piezoelectric ceramic sheets with the same structure and polarization along the thickness direction. The first to fourth piezoelectric ceramic sheets are attached to the center of the end face of the first to fourth side plates and the hollow screw on the same side in a clockwise direction. The fifth to eighth piezoelectric ceramic sheets are attached to the center of the other end face of the first to fourth side plates respectively. The first to fourth piezoelectric ceramic sheets and the fifth to eighth piezoelectric ceramic sheets are symmetrically corresponding to each other. The long side of the first to eighth piezoelectric ceramic sheets is parallel to the long side of the side plate on which they are located. The first, fourth, fifth, and eighth piezoelectric ceramic sheets have the same polarization direction. The second, third, sixth, and seventh piezoelectric ceramic sheets have the same polarization direction. The first and second piezoelectric ceramic sheets have opposite polarization directions. The lower end of the clamping plate is fixedly connected to the base, and a cross-shaped through hole is provided in the center for cooperating with the metal substrate; The first to fourth ear pieces are all fixedly connected to the clamping plate, so that the metal substrate is located in the cross-shaped through hole of the clamping plate, and the hollow screw and the center plate are coaxial. The dual rotors include a front rotor, a rear rotor, a threaded cylinder, first and second preload bolts, first and second preload springs, and first and second preload nuts; Both the front rotor and the rear rotor are annular in shape, and their inner walls are provided with internal threads for cooperating with the hollow screw. The rear rotor is symmetrically provided with two countersunk through holes that respectively cooperate with the first preload bolt and the second preload bolt; the front rotor is symmetrically provided with two through holes that respectively cooperate with the first preload bolt and the second preload bolt. Both the front rotor and the rear rotor are threadedly connected to the hollow screw, with a gap between them. The rear rotor is located between the front rotor and the clamping plate. The first preload bolt and the second preload bolt pass through the corresponding countersunk holes on the rear rotor and the corresponding through holes on the front rotor, respectively, and are threadedly connected to the first preload nut and the second preload nut. The first preload spring and the second preload spring are respectively fitted onto the studs of the first preload bolt and the second preload bolt, with one end abutting against the first preload nut and the second preload nut, respectively, and the other end abutting against the front rotor. The first and second preload bolts, the first and second preload springs, and the first and second preload nuts are used to provide preload. The threaded cylinder is a hollow cylinder with openings at both ends. Its inner wall is provided with internal threads for mating with the hollow screw, and its length is greater than the length of the hollow screw. One end of the threaded cylinder is coaxially and fixedly connected to the end of the front rotor away from the rear rotor, and the threaded cylinder and the hollow screw are threadedly connected. The threaded end of the Luer connector is threadedly connected to the end of the threaded cylinder away from the front rotor, and the tapered end is engaged with the male Luer tapered surface of the medical puncture needle.
2. The MRI-compatible cross-plate screw-type piezoelectrically driven trocar according to claim 1, characterized in that, The clamping plate has first to fourth grooves on one end face for cooperating with the first to fourth lugs, and each of the first to fourth grooves has a through hole for cooperating with bolts. The clamping plate has fifth to eighth grooves on the other end face, which correspond one-to-one with the first to fourth grooves. The first to fourth lugs are fixed to the clamping plate by four bolts and four nuts. The four bolts are located in the first to fourth grooves, and the four nuts are located in the fifth to eighth grooves.
3. The working method of the MRI-compatible cross-plate screw-type piezoelectrically driven trocar as described in claim 1, characterized in that, Includes the following steps: If the puncture needle needs to complete tangential rotation and linear feed, a preset A-phase simple harmonic voltage signal is applied to the first, third, fifth, and seventh piezoelectric ceramic plates, and a preset B-phase simple harmonic voltage signal is applied to the second, fourth, sixth, and eighth piezoelectric ceramic plates. The B-phase simple harmonic voltage signal and the A-phase simple harmonic voltage signal have a 90° phase difference. At this time, the metal substrate generates two orthogonal second-order bending vibration deformations, which in turn induce two orthogonal bending vibrations on the hollow screw. The hollow screw is coupled into a positive-direction rotating "head-shaking" motion. The external thread friction on the screw drives the dual rotor motion, realizing the rotating linear needle insertion motion, that is, realizing the "twisting-insertion" motion of the puncture needle. If the puncture needle needs to complete reverse rotation and linear retraction, that is, to achieve the "twisting-lifting" movement of the puncture needle, the phase difference between the B-phase simple harmonic voltage signal and the A-phase simple harmonic voltage signal can be adjusted to -90°.