CN-122005037-A - Radial pressure sensing pedicle screw for internal fixation of vertebral column

Abstract

A radial pressure sensing pedicle screw for backbone internal fixation carries out integrated with sensitive membrane pressure sensing structure and pedicle screw inner space, can realize the real-time supervision to screw lateral wall radial pressure under the prerequisite that does not show to weaken screw mechanical properties. The structure has the advantages of compact structure, clear force transmission path, sensitive response, good repeatability, suitability for microminiaturization integration and the like, can provide a new technical path for intelligent perception of intelligent pedicle screws and orthopedic internal fixation instruments, and has good clinical application prospect.

Inventors

• HE SHAOQI
• XIE MIN
• TANG CHENGXUAN
• ZHAO XIAOYU
• ZHONG XIQIANG
• WEN JIAHONG
• LI XIN
• LI YIMIN

Assignees

• 瑞安市人民医院(瑞安市人民医院医疗服务集团瑞安市红十字医院)

Dates

Publication Date

20260512

Application Date

20260326

Claims (7)

1. 1. The utility model provides a radial pressure sensing pedicle screw for backbone internal fixation, includes screw body (1), its characterized in that, screw body (1) in be equipped with cavity (11), cavity (11) in be provided with module carrier (2), module carrier (2) include first cylinder structure (21) and second cylinder structure (22), first cylinder structure (21) and second cylinder structure (22) between be crisscross setting and intercommunication each other, the lateral wall of screw body (1) on seted up the side direction through-hole, the both ends of first cylinder structure (21) and second cylinder structure (22) of module carrier (2) correspond respectively and set up the side direction through-hole department at the lateral wall, the both ends of first cylinder structure (21) and second cylinder structure (22) all be equipped with sensitive membrane module (3).
2. 2. A radial pressure sensing pedicle screw for spinal fixation according to claim 1, characterized in that the sensing diaphragm assembly (3) comprises a sensing diaphragm body (31) and a piezoresistor (32) arranged on the sensing diaphragm body (31), the piezoresistor (32) being arranged in a high strain area of the sensing diaphragm body (31) and extending in a tangential direction of the diaphragm of the sensing diaphragm body (31).
3. 3. A radial pressure sensing pedicle screw for intraspinal fixation according to claim 2, characterized in that the number of piezoresistors (32) on each of said sensing membrane bodies (31) is four, four of said piezoresistors (32) forming a wheatstone bridge configuration for converting radial pressure induced membrane deformations into electrical signals for output.
4. 4. A radial pressure sensing pedicle screw for spinal fixation according to claim 1, characterized in that the modular carrier (2) further comprises a carrier support (23), the carrier support (23) being fixed in a crisscrossed arrangement with a first cylindrical structure (21) and a second cylindrical structure (22) communicating with each other.
5. 5. A radial pressure sensing pedicle screw for spinal fixation as claimed in claim 2, wherein the sensing membrane body (31) is of SOI silicon-based construction comprising top silicon, buried oxide layer and bottom silicon, wherein the top silicon is of deformable membrane construction.
6. 6. A radial pressure sensing pedicle screw for intraspinal fixation as claimed in claim 5, characterized in that the outer side of the sensitive membrane module (3) is also provided with a biocompatible sealing layer preventing the ingress of body fluids.
7. 7. A radial pressure sensing pedicle screw for spinal fixation according to claim 1, characterized in that the module carrier (2) is also provided with a signal transmission unit, and the sensitive membrane assembly (3) is electrically connected with the signal transmission unit by conductive leads.

Description

Radial pressure sensing pedicle screw for internal fixation of vertebral column Technical Field The invention relates to the technical field of medical implantation instruments, in particular to a radial pressure sensing pedicle screw for internal fixation of a vertebral column. Background Pedicle screws are widely used in spinal internal fixation surgery, and stability of the pedicle screws directly influences postoperative fusion effect. The existing clinic mainly relies on hand feeling in operation and postoperative images to judge the contact state of the screw and bone tissue, and lacks a real-time and quantitative mechanical feedback means. The existing screw mechanics monitoring scheme mostly adopts an axial tension-compression or torque monitoring mode, so that radial contact pressure between a screw and a pedicle bone wall is difficult to effectively reflect, and the sensor is large in size and is unfavorable for integration in a limited space of the screw. The existing MEMS pressure sensor is designed aiming at plane loading or cavity pressure environment, and when the existing MEMS pressure sensor is directly applied to the inside of a screw, the problems of unmatched stress direction, easy damage due to overload, difficult packaging and the like exist. Thus, there is a need for a pressure sensing scheme that is adaptable to the interior of pedicle screws, capable of sensing radial pressure, compact in construction, and resistant to overload. Disclosure of Invention In order to solve the defect and the defect that the prior art that the pedicle screw lacks of monitoring the contact state of the screw and bone tissue in real time, the invention provides a radial pressure sensing pedicle screw for internal fixation of the vertebral column, a miniature sensitive membrane pressure sensing chip is integrated in the pedicle screw, and a module carrier with a specific structural form is combined, the method realizes the effective transmission of radial pressure on the side wall of the screw to the sensitive film, so that the sensitive film generates detectable deformation under the action of radial load, thereby realizing the real-time perception of contact pressure of the screw-bone tissue interface and providing a technical foundation for the stability evaluation and the intelligent internal fixation of the screw after operation. The radial pressure sensing pedicle screw for the internal fixation of the vertebral column comprises a screw body, wherein a hollow cavity is formed in the screw body, a module carrier is arranged in the hollow cavity, the module carrier comprises a first cylindrical structure and a second cylindrical structure, the first cylindrical structure and the second cylindrical structure are arranged in a crisscross manner and are communicated with each other, lateral through holes are formed in the side wall of the screw body, two ends of the first cylindrical structure and two ends of the second cylindrical structure of the module carrier are respectively and correspondingly arranged at the lateral through holes of the side wall, and sensitive membrane assemblies are arranged at two ends of the first cylindrical structure and two ends of the second cylindrical structure. Further, the sensitive film component comprises a sensitive film body and a piezoresistor arranged on the sensitive film body, wherein the piezoresistor is arranged in a high-strain area of the sensitive film body and extends along the tangential direction of the film sheet of the sensitive film body. Further, the number of piezoresistors on each sensitive film body is four, and the four piezoresistors form a Wheatstone bridge structure and are used for converting diaphragm deformation caused by radial pressure into electric signals to be output. Further, the module carrier also comprises a carrier bracket, wherein the carrier bracket is fixed into a first cylindrical structure and a second cylindrical structure which are arranged in a crisscross manner and are communicated with each other. Further, the sensitive film body adopts an SOI silicon-based structure, and the SOI silicon-based structure comprises a top silicon layer, an oxygen buried layer and a bottom silicon layer, wherein the top silicon layer is a deformable membrane structure. Further, the outer side of the sensitive membrane component is also provided with a biocompatible sealing layer for preventing body fluid from entering. Further, a signal transmission unit is further arranged in the module carrier, and the sensitive film component is electrically connected with the signal transmission unit through a conductive lead. Preferably, the diameter of the hollow cavity is 2mm, and the diameter of the radial hole is 1mm, so that the effective radial pressure transmission is realized while the integral mechanical strength of the screw is ensured. Preferably, the module carrier is formed by intersecting two cylindrical structures with the length of 6.2mm