CN112336391A

CN112336391A - Spinal nerve root stress sensing microsystem

Info

Publication number: CN112336391A
Application number: CN201910553538.8A
Authority: CN
Inventors: 张琪; 李彩丽; 王凯丰; 张旭
Original assignee: Haining Advanced Semiconductor And Intelligent Technology Research Institute
Current assignee: Haining Advanced Semiconductor And Intelligent Technology Research Institute
Priority date: 2019-08-09
Filing date: 2019-08-09
Publication date: 2021-02-09

Abstract

The invention provides a spinal nerve stress sensing microsystem, which comprises a flexible pressure sensor and a nerve root retractor. The flexible pressure sensor is of a capacitance structure and consists of a protective layer, an induction layer, a pressure-sensitive layer and an analysis layer. The induction layer is a flexible material with good electric conductivity; the pressure-sensitive layer is a high-density microneedle structure array based on a flexible elastic material; the analysis layer is a pad array of the FPCB; the protective layer is a sensor package and is of a hollow five-face cuboid structure. The nerve root retractor is of a hollow structure, consists of a hook head, a hook rod and a handle, and is prepared from medical stainless steel. The spinal nerve stress sensing microsystem is characterized in that: the nerve root retractor provided with the flexible pressure sensor can quantify stress of a nerve root in a three-dimensional space in an operation, and pre-warning is carried out in real time by utilizing the display module to prevent the nerve from being damaged. Aiming at the defects of the traditional nerve root retractor, the invention provides guarantee for the safe implementation of the spinal surgery and has positive clinical practical significance.

Description

Spinal nerve root stress sensing microsystem

Technical Field

The disclosure belongs to the technical field of sensing technology and biomedicine, and relates to a spinal nerve root stress sensing microsystem.

Background

The number of patients with spinal diseases in the society is increasing nowadays, and the daily life and work of people are seriously influenced by the spinal diseases. Nerve root retractors are spinal surgery: instruments necessary for the enucleation and lumbar fusion are used to sufficiently expose the operation area in operations such as removal of a protruding nucleus pulposus or removal of a nucleus pulposus and implantation of an artificial nucleus pulposus and an intervertebral fusion device into the intervertebral space. Periodically pulling the nerve roots to the opposite side of the operation during the operation using a nerve root retractor is a standard surgical procedure. The operation area of the nerve root in the operation is only 1.5cm multiplied by 2cm, the nerve root is extremely narrow, the nerve root is easily affected by the actions of traction, extrusion and the like, and the nerve root is easily damaged due to improper operation. The degree and time of nerve root retractor traction on nerve roots is an important factor affecting the success rate of spinal surgery.

The traditional nerve root retractor cannot accurately quantify the three-dimensional stress condition of the nerve root, judge the tensity of the nerve root by virtue of long-term accumulated experience of a surgeon to carry out operation in the operation, and cannot judge the acting force of the nerve root retractor on the nerve root. The operation visual field cannot be fully exposed due to insufficient traction on nerve roots, great difficulty is brought to the removal of intervertebral discs, and the nerve roots are damaged due to improper operation of instruments; iatrogenic nerve function damage is easily caused by excessive traction on nerve roots, and a lumbar operation failure syndrome appears after a patient operates. Meanwhile, the traditional nerve root retractor cannot dynamically monitor the damaged condition of the nerve root in real time, and doctors need to interrupt the operation for many times to monitor the damaged degree of the nerve root in the operation, so that the operation efficiency is low and the operation time is long. The problem with the conventional nerve root retractor is one of the problems that need to be solved urgently in the spinal surgery.

Therefore, aiming at the defects of the traditional nerve root retractor, a spinal nerve stress sensing microsystem integrating a flexible pressure sensor is needed to be developed, the size and the position of the three-dimensional space stress of the nerve root in the operation are quantized, the safety implementation of the spinal surgery is guaranteed, the success rate of the operation is increased, and the spinal nerve stress sensing microsystem has positive clinical practical significance.

Disclosure of Invention

The utility model provides a spinal cord nerve atress sensing microsystem of integrated flexible pressure sensor for the real time monitoring of the three-dimensional space atress of nerve root in the art, in time early warning when the nerve root is impaired.

The spinal nerve root stress sensing microsystem consists of a flexible pressure sensor and a nerve root retractor.

The flexible pressure sensor is shown in fig. 1 and comprises a protective layer 1, a sensing layer 2, a pressure sensitive layer 3 and an analysis layer 4. The pressure sensor adopts a capacitive sensor structure, wherein the sensing layer 2 is an upper electrode layer of the capacitive structure and is used for sensing the pressure of a three-dimensional space; the pressure-sensitive layer 3 is a dielectric layer with a capacitance structure and is used for transmitting the pressure sensed by the sensing layer; the analysis layer 4 is a lower electrode layer of a capacitance structure and is used for calculating and analyzing the pressure and the position acting on the sensor.

The induction layer 2 is of a rectangular structure, and flexible conductive materials with good conductive performance are utilized: polyethylene dioxythiophene/polystyrene sulfonic acid (PEDOTS/PSS) or graphene or conductive fabric.

The pressure-sensitive layer 3 is a high-density microneedle structure array. The mold turning technology is utilized, and the high-elasticity flexible material can be prepared from Polydimethylsiloxane (PDMS). Firstly, preparing a microneedle structure mould, and then dripping PDMS on the mould; coating PDMS on the mould uniformly by using a spin coater; and heating and curing the micro-needle structure by using an oven to obtain the required micro-needle structure.

The analysis layer 4 is a rectangular array of detection cells. A pad preparation using a Flexible Printed Circuit Board (FPCB). As shown in FIG. 2, the force-bearing position of the sensor is obtained by dividing the sensing units into regions according to the force-bearing proportion between each sensing unit. High data flux is guaranteed under the condition of small area, and the pressure information is collected and integrated by utilizing the sensing of multiple sensing units to obtain complete and comprehensive pressure information.

The protective layer 1 is used for packaging the pressure sensor and is prepared by using an over-mold technology. First a protective layer mould is prepared as shown in figure 3, comprising an inner mould 5 and an outer mould 6. The inner mold 5 has a protruding rectangular parallelepiped structure; outer mould 6 has sunken cuboid structure, wraps up interior mould 5, to outer mould 6 material PDMS that pours into, interior mould 5 is pressed down, extrudes unnecessary PDMS, is filled with PDMS in the two clearance. Wherein, the inner die 5 is closely attached to one surface of the outer die 6, and the distance that the inner die 5 can be pressed down is controlled by utilizing the oblique angle of the edge boss, so that the thickness of the protective layer is ensured. And (3) placing the mould filled with the PDMS into an oven for curing, and taking down the mould to obtain the hollow cuboid protective layer without two surfaces as shown in figure 4. And (3) depositing a layer of PDMS on the hook head of the nerve root retractor, curing, putting the protective layer obtained by demolding and the hook head deposited with the PDMS into a plasma degumming machine for bombardment, and bonding the protective layer and the hook head to obtain the five-surface hollow cuboid protective layer shown in figure 5. The sensor is then placed inside the protective layer.

The nerve root retractor is shown in fig. 6, and comprises a hook head 7, a hook rod 8, a hook rod 9 and a handle 10, and is made of medical stainless steel and is of an L shape, wherein the hook rod 8 is of an isosceles trapezoid, a transition area of the hook rod 9 close to the hook rod 8 is of an isosceles trapezoid, a position of the hook rod 9 close to the handle 10 is of a rectangle, and a transition area of the hook rod 8 and the hook rod 9 is of a quarter circular arc.

The nerve root retractor is provided with an upper cover layer and a lower shell layer. After the upper cover layer and the lower shell layer are fastened, a hollow structure is formed in the middle and used for placing a sensor and an FPCB. Wherein the proximal end of the hook head of the hook stem 8 carries a pressure sensor, the outer surface of the sensor being oriented in line with the hook head, as shown in fig. 7; the handle is provided with a data processing module, a Bluetooth module, an alarm module and a battery module.

The display system is loaded at the nerve root retractor handle; the pressure sensor can also be positioned on a display of an upper computer, and the Bluetooth module is utilized to transmit pressure data.

The protective layer of the pressure sensor and the nerve root retractor bombard the surface by using a plasma degumming machine to remove surface contamination particles, so that the adhesion of the protective layer and the nerve root retractor is realized.

After all modules are assembled, a parylene thin layer grows on the surface of the nerve root retractor, and surface packaging with good flexibility, sealing property, anti-interference property and biocompatibility is achieved.

The spinal nerve stress sensing microsystem can detect pressure and simultaneously display the stress of nerve roots on a display system in real time, and the display system can be digital or dial; the data processing module judges the damaged condition of the nerve root in time, and when the damaged condition of the nerve root approaches to an unrecoverable threshold value, the alarm module gives an alarm to remind a doctor to adjust the traction of the nerve root in real time.

The spinal nerve stress sensing microsystem can accurately detect the pressure of a nerve root in a three-dimensional space and the stress position of a sensor, monitors the damage condition of the nerve root in real time, and carries out damage early warning. The nerve root retractor can replace the traditional medical nerve root retractor, systematically regulates and controls the acting force of the nerve root retractor on nerve roots, prevents failure syndrome of lumbar vertebra operation, realizes real-time feedback of the stress condition of the nerve roots, and provides a better medical instrument for treating lumbar disc herniation.

The foregoing description is intended to be illustrative rather than limiting, and it will be appreciated by those skilled in the art that many modifications, variations or equivalents may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Drawings

FIG. 1 is a schematic structural diagram of a flexible sensor, which comprises a protective layer 1, a sensing layer 2, a pressure-sensitive layer 3 and an analysis layer 4;

FIG. 2 is a schematic diagram of a flexible sensor analysis layer structure;

FIG. 3 is a schematic diagram of a flexible sensor cover mold, including an inner mold 5 and an outer mold 6;

FIG. 4 is a schematic view of a part of a protective layer mold obtained by rollover;

FIG. 5 is a schematic diagram of a five-face hollow cuboid protective layer of the flexible sensor;

fig. 6 is a schematic view of a nerve root retractor, which comprises a hook head 7, a hook rod 8, a hook rod 9 and a handle 10;

figure 7 is a schematic view of a nerve root retractor equipped with a flexible pressure sensor.

Claims

1. Spinal cord nerve atress sensing microsystem, including flexible pressure sensor and nerve root retractor, its characterized in that:

the flexible pressure sensor comprises protective layer 1, inductive layer 2, pressure sensitive layer 3 and analysis layer 4, and protective layer 1 is the sensor encapsulation, and inductive layer 2 is the upper electrode layer, and analysis layer 4 is the lower electrode layer, and pressure sensitive layer 3 is located inductive layer 2 and analysis layer 4 are middle, and the nerve root retractor comprises gib head 5, gib rod 6, gib rod 7 and handle 8.

2. The sensing layer 2 of claim 1 is a flexible conductive material with good conductive properties, which can be PEDOTS/PSS or graphene or conductive fabric.

3. The pressure-sensitive layer 3 according to claim 1 is a high-density microneedle array, and is made of a highly elastic flexible material, such as PDMS (polydimethylsiloxane), which is a good pressure transmission body.

4. The analysis layer 4 according to claim 1 is a pad array of FPCB for detecting the magnitude of pressure and detecting the main force-receiving position of the pressure sensor according to the magnitude of pressure.

5. The protective layer 1 according to claim 1 is a hollow, five-sided cuboid structure based on PDMS, prepared using the overmolding technique.

6. The nerve root retractor of claim 1, which is of an "L" shape, is composed of an upper cover layer and a lower shell layer, and is made of medical stainless steel.

7. The hook head 5 of the nerve root retractor of claim 1 is fitted with a flexible pressure sensor, the sensor outer surface facing in line with the hook head facing.

8. The hook lever 6 and the hook lever 7 of the nerve root retractor according to claim 1 assemble an FPCB.

9. The handle 8 of the nerve root retractor of claim 1 is loaded with a data processing module, a bluetooth module, an alarm module, a battery module, a display module.

10. The alarm module of claim 9, wherein the alarm module provides a voice alarm when the pressure value output to the data processing module by the sensor exceeds a pressure threshold value.

11. The display module of claim 9 displays in real time the pressure magnitude and pressure location output by the sensor to the data processing module.

12. The display module of claim 9 can be mounted to the handle or located in the upper computer software.

13. The bluetooth module of claim 9 for transmitting data processing module data to host computer software.

14. The battery module of claim 9 for powering a data processing module, a display module, and a bluetooth module.