A brain contact interaction force sensor based on FBG

Abstract

The application discloses a brain contact interactive force sensor based on FBG, which comprises a coaxial shell, an instrument connecting piece, a flexible round pipe and a thrust pin; the flexible round pipe and the thrust pin are installed in the shell; the instrument connecting piece is located at the second end of the shell; one end of the flexible round pipe is fixedly connected with the shell, and the other end is fixedly connected with the thrust pin; a flexible groove segment is arranged in the middle of the flexible round pipe; circumferential optical fibers are uniformly distributed on the inner wall of the flexible round pipe in the circumferential direction; the two end portions of the circumferential optical fibers are fixedly installed on the flexible round pipe; the grating segment of the circumferential optical fiber is opposite to the position of the flexible groove segment; one end of the thrust pin is abutted against the inside of the first end of the shell, and the other end is fixedly connected with the instrument connecting piece; the thrust pin is provided with a thrust pin central hole, and a notch is arranged in the middle; a central optical fiber is fixedly installed in the thrust pin central hole of the thrust pin; the grating segment of the central optical fiber is opposite to the position of the notch. The force sensor has high adaptability and stable force measurement.

Description

Technical Field

[0001] This invention belongs to the technical field, specifically relating to a brain contact interaction force sensor based on FBG. Background Technology

[0002] With the development of neurosurgical robots and remote manipulation technology, contact force sensing between robotic end-effectors and brain tissue has gradually become an important technology for improving surgical safety. Brain tissue is soft and fragile; during procedures such as aspiration, irrigation, clamping, and hemostasis, excessive contact force applied by the end-effectors can cause secondary damage. Existing force sensing technologies mainly include resistive strobe sensors, piezoelectric sensors, piezoresistive sensors, and fiber Bragg grating sensors. Among these, resistive strobe sensors and piezoresistive sensors have relatively mature structures, but they are easily limited by electromagnetic interference and sterilization issues in the neurosurgical environment. Piezoelectric sensors are suitable for dynamic force detection, but have limitations in measuring low-frequency or static contact forces. In contrast, fiber Bragg grating sensors have advantages such as small size, resistance to electromagnetic interference, applicability to micro-strain measurement, and ease of long-distance signal transmission, making them suitable for integration with surgical robot end-effectors.

[0003] Currently, there are several surgical force sensor solutions based on fiber Bragg gratings. For example, Chinese patent application CN108593161A, entitled "A Three-Dimensional Force Sensor for Minimally Invasive Surgical Robots Based on Fiber Bragg Gratings," employs four pairs of optical Bragg gratings and obtains three-dimensional force information through grating wavelength changes and decoupling algorithms. This solution is mainly used for three-dimensional force measurement of instruments in minimally invasive surgical robots. Another Chinese patent, CN111803143B, entitled "A Three-Dimensional Force Sensor for Minimally Invasive Surgery," uses three optical fiber sensors evenly distributed at 120° circumferential angles on the outer surface of a hollow metal tube. This solution is suitable for force detection at the tip of minimally invasive surgical needles. Finally, Chinese patent CN115290243B, entitled "A Three-Dimensional Force Sensor and Measurement System for Minimally Invasive Surgery," includes a hollow flexible deformable structure and multiple fiber Bragg gratings, with the central fiber used to measure axial force and the circumferential fibers used to measure radial force.

[0004] The existing fiber optic force sensors mentioned above are all structurally designed for single surgical instruments, highly integrated with the instrument body. The sensor size, installation position, and force path all depend on the shape and usage of a particular instrument. Therefore, when using different instruments in craniocerebral surgery, it is difficult to standardize the force sensors, which affects the accuracy of force measurement and increases the structural complexity of the end-effector, raising manufacturing costs and integration difficulties. Furthermore, while FBGs have high sensitivity and good response stability to circumferential tensile strain, they are more difficult to decouple directly from the local compression or non-uniform bending response caused by complex contact pressure. Additionally, if force measurement is achieved by measuring the FBG compressive strain, pre-stretching the FBG is required, which is difficult to implement in practice. Existing technologies rarely include structural designs that convert the pressure on the instrument into circumferential tensile force on the FBG, leading to insufficient sensitivity and unstable calibration relationships in craniocerebral soft tissue contact scenarios. Finally, existing multi-dimensional fiber optic force sensors for neurosurgical instruments are generally large in size. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, this invention provides a brain-based contact interaction force sensor with strong adaptability and stable force measurement.

[0006] To achieve the above objectives, the present invention adopts the following specific technical solution:

[0007] In a first aspect, the present invention provides a brain-based contact interaction force sensor, which includes a housing, an instrument connector, a flexible cylindrical tube, a thrust pin, a circumferential optical fiber, and a central optical fiber; the housing, the instrument connector, the flexible cylindrical tube, and the thrust pin are all coaxially arranged; the flexible cylindrical tube and the thrust pin are installed inside the housing. The outer shell is a cylindrical hollow structure, and has a first end and a second end along its axial direction; The instrument connector is a disc-shaped structure and is located at the second end of the outer shell; The flexible circular tube is sleeved on the outer periphery of the thrust pin, with one end fixedly connected to the second end of the outer shell and the other end fixedly connected to the thrust pin; a flexible groove segment capable of elastic deformation under stress is provided in the middle of the flexible circular tube; three circumferential optical fibers are evenly distributed along the inner wall of the flexible circular tube; both ends of the circumferential optical fibers are fixedly installed on the inner wall of the flexible circular tube; the grating section of the circumferential optical fiber is positioned opposite to the flexible groove segment; the circumferential optical fiber is used to measure the strain caused by external force. One end of the thrust pin abuts against the inside of the first end of the outer shell, and the other end is fixedly connected to the instrument connector; the thrust pin is provided with a thrust pin center hole and a groove in the middle; the central optical fiber is fixedly installed in the thrust pin center hole of the thrust pin; the grating section of the central optical fiber is opposite to the groove; the central optical fiber is used for temperature compensation of the circumferential optical fiber.

[0008] Furthermore, the flexible circular tube is made of stainless steel tube by machining, and its inner wall is provided with optical fiber bonding grooves that correspond one-to-one with the two ends of the circumferential optical fiber and are shaped to fit it; the wall thickness of the flexible groove segment is less than the wall thickness of the rest of the flexible circular tube. Both ends of the circumferential optical fiber are fixed in the optical fiber bonding groove and cured with UV adhesive.

[0009] Furthermore, the outer casing is provided with a central hole, and a casing positioning protrusion is provided in the central hole at the second end; One end of the flexible tube is provided with a flexible segment positioning groove that corresponds one-to-one with the positioning protrusion of the outer shell and matches its shape. The flexible tube and the outer shell are fixed together by the corresponding positioning protrusion of the outer shell and the flexible segment positioning groove in a locking and bonding manner.

[0010] Furthermore, a connector positioning protrusion is provided in the central hole of the instrument connector; The end of the thrust pin is provided with a thrust pin positioning groove that corresponds one-to-one with the positioning protrusion of the connector and fits in shape; the thrust pin and the instrument connector are fixed together by a set screw through the corresponding positioning protrusion of the connector and the positioning groove of the thrust pin.

[0011] Furthermore, the two ends of the central optical fiber are installed in the center hole of the thrust nail by UV adhesive.

[0012] Furthermore, the instrument connector is provided with a connector threaded hole; the connector threaded hole is used for threaded connection with neurosurgical instruments or end effectors.

[0013] Furthermore, the first end of the housing is provided with a platform threaded hole, which is used for threaded connection with the end platform.

[0014] In a second aspect, the present invention also provides a force sensing system for a neurosurgical robot, which includes the aforementioned brain contact interaction force sensor, optical fiber, FBG demodulator, temperature compensation and force decoupling module, and robot control and force feedback module. The optical fiber is connected to the central optical fiber and the circumferential optical fiber of the brain contact interaction force sensor, and is used to transmit the optical signals of the central optical fiber and the circumferential optical fiber to the FBG demodulator. The FBG demodulator is used to collect the center wavelength changes of the central optical fiber and the circumferential optical fiber. The temperature compensation and force decoupling module is used to perform temperature compensation on each circumferential fiber according to the output of the central fiber, and to calculate the axial force, radial force and torsional moment using the decoupling matrix. The robot control and force feedback module is used to adjust the movement of the surgical robot or provide force feedback to the operator based on the calculation results of the temperature compensation and force decoupling module.

[0015] Thirdly, the present invention also provides an application of the above-mentioned force sensing system for neurosurgical robots, which is used to monitor the contact force between surgical instruments and brain tissue in real time during craniocerebral surgery and control the surgical instruments according to the contact force.

[0016] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: 1. Existing sensors are mostly designed for single instruments and are difficult to use directly on different surgical platforms. The brain contact interaction force sensor of this invention has strong adaptability. The sensor is modularized and can be directly installed on the end effector of robots such as suction devices and hemostatic forceps, reducing the need to repeatedly design sensor structures for different instruments.

[0017] 2. Most existing FBG sensors directly bear external pressure or bending deformation, which easily causes light to be affected by non-uniform strain such as compression and shearing. Compared with existing FBG force sensors, the brain contact interactive force sensor of this invention converts the pressure on the device into the stretching of the FBG to generate strain, which improves the repeatability of the measurement and makes the force signal more stable.

[0018] 3. Compared with existing force sensors used in neurosurgery, the brain contact interaction force sensor of the present invention has a more compact and small structure. The outer diameter of the sensor is only 23mm and the total length is 22mm, which can complete multi-dimensional force detection in a small space. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the FBG-based brain contact interaction force sensor of the present invention. Figure 2 This is a schematic diagram of the exploded structure of the FBG-based brain contact interaction force sensor of the present invention. Figure 3 This is a schematic diagram of the circumferential fiber arrangement; Figure 4 A schematic diagram of the central fiber optic cable arrangement; Figure 5 This is a schematic diagram illustrating the working principle of the FBG-based brain-contact interactive force sensor of the present invention. Figure 6This is a schematic diagram of the installation of the FBG-based brain contact interaction force sensor and attractor of the present invention; Figure 7 This is a schematic diagram of the installation of the FBG-based brain contact interaction force sensor and bipolar electrocoagulation hemostatic forceps of the present invention.

[0020] Figure label: 1-Outer shell, 2-Instrument connector, 3-Flexible round tube, 4-Thrust pin, 5-Circumferential fiber optic, 6-Central fiber optic, 11-Outer shell positioning protrusion, 21-Connector positioning protrusion, 22-Connector threaded hole, 31-Connector positioning protrusion, 31-Flexible segment positioning groove, 32-Fiber optic bonding groove, 33-Flexible groove segment, 41-Thrust pin positioning groove, 42-Thrust pin central hole, 43-Groove, 100-Brain contact interactive force sensor, 101-Aspirator, 102-Connector one, 201-Connector two, 202-Electrocoagulation hemostatic forceps. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1 This embodiment provides a brain-based contact interaction force sensor 100, such as... Figure 1 and Figure 2 As shown, the brain-contact interaction force sensor 100 includes a housing 1, a device connector 2, a flexible circular tube 3, a thrust pin 4, a circumferential optical fiber 5, and a central optical fiber 6; wherein: like Figure 2 As shown, the outer shell 1 is a cylindrical hollow structure with a first end and a second end along its axial direction. The first end of the outer shell 1 is... Figure 1 The top of the inner shell 1, and the second end of the outer shell 1 are Figure 1 The bottom end of the outer shell 1, that is, the end of the outer shell 1 closest to the instrument connector 2. The instrument connector 2 has a disc-shaped structure and is located at the second end of the outer shell 1. The outer shell 1, instrument connector 2, flexible cylindrical tube 3, and thrust pin 4 are all coaxially arranged. The flexible cylindrical tube 3 and thrust pin 4 are installed inside the outer shell 1.

[0023] like Figure 1 , Figure 3 and Figure 5As shown, the flexible circular tube 3 is sleeved on the outer periphery of the thrust nail 4, with one end fixedly connected to the second end of the outer shell 1 and the other end fixedly connected to the thrust nail 4. A flexible groove segment 33, capable of elastic deformation under stress, is provided in the middle of the flexible circular tube 3; three circumferential optical fibers 5 are evenly distributed along the inner wall of the flexible circular tube 3, i.e., the circumferential optical fibers 5 are evenly distributed at 120° along the circumference of the flexible circular tube 3; both ends of the circumferential optical fibers 5 are fixedly installed on the inner wall of the flexible circular tube 3; the grating section of the circumferential optical fiber 5 is positioned opposite to the flexible groove segment 33; the circumferential optical fiber 5 is used to measure the strain caused by external force. The flexible circular tube 3 is made of stainless steel tube through machining, and its inner wall is provided with optical fiber bonding grooves 32 that correspond one-to-one with the two ends of the circumferential optical fibers 5 and are shaped to fit them; the wall thickness of the flexible groove segment 33 is less than the wall thickness of the rest of the flexible circular tube 3; both ends of the circumferential optical fibers 5 are fixed in the optical fiber bonding grooves 32 and cured with UV adhesive. When installing the circumferential fiber 5, first insert the circumferential fiber 5 into the vicinity of the fiber bonding groove 32 from inside the flexible circular tube 3. The fiber bonding groove 32 is an inner groove machined from a stainless steel tube and pre-coated with UV glue. When both ends of the circumferential fiber 5 are placed in the fiber bonding groove 32, the fiber bonding groove 32 is irradiated with ultraviolet light to solidify the UV glue. The FBG part of the circumferential fiber 5 is located in the flexible groove segment 33.

[0024] like Figure 1 , Figure 4 and Figure 5 As shown, one end of the thrust pin 4 abuts against the inside of the first end of the outer casing 1, and the other end is fixedly connected to the instrument connector 2. The thrust pin 4 is provided with a thrust pin center hole 42 and a slot 43 in the middle. The central optical fiber 6 is fixedly installed in the thrust pin center hole 42 of the thrust pin 4. The grating section of the central optical fiber 6 is opposite to the slot 43. The central optical fiber 6 is used for temperature compensation of the circumferential optical fiber 5. The two ends of the central optical fiber 6 are installed in the thrust pin center hole 42 of the thrust pin 4 by UV adhesive curing. When installing the central optical fiber 6, the central optical fiber 6 is directly inserted into the thrust pin center hole 42. The two ends of the thrust pin center hole 42 are pre-coated with UV adhesive. When the central optical fiber 6 is located at both ends of the thrust pin center hole 42, the two ends of the thrust pin center hole 42 are irradiated with ultraviolet light to make the UV adhesive solidify. The FBG part of the central optical fiber 6 is located in the slot 43 in the middle of the thrust pin 4.

[0025] like Figure 1 As shown, the outer shell 1 has a central hole and is a hollow structure; a shell positioning protrusion 11 is provided in the central hole at the second end of the outer shell 1; a flexible segment positioning groove 31 is provided at one end of the flexible tube 3, which corresponds to the shell positioning protrusion 11 and is shaped and fits the flexible segment positioning groove 31; the flexible tube 3 and the outer shell 1 are fixed together by the corresponding shell positioning protrusion 11 and the flexible segment positioning groove 31 in a locking and bonding manner.

[0026] like Figure 2As shown, a connector positioning protrusion 21 is provided in the center hole of the instrument connector 2; the end of the thrust nail 4 is provided with a thrust nail positioning groove 41 that corresponds to and matches the connector positioning protrusion 21; the thrust nail 4 and the instrument connector 2 are fixed by a set screw through the corresponding connector positioning protrusion 21 and the thrust nail positioning groove 41.

[0027] like Figure 2 The instrument connector 2 is provided with a connector threaded hole 22; the connector threaded hole 22 is used for threaded connection with neurosurgical instruments or end effectors. The first end of the housing 1 is provided with a platform threaded hole, which is used for threaded connection with an end platform. For example... Figure 6 The diagram shows the assembly structure of the brain contact interaction force sensor 100 and the suction device 101 in this embodiment. The first end of the outer shell 1 of the brain contact interaction force sensor 100 is detachably mounted to the left end of the connector 102 via screws. The instrument connector 2 of the brain contact interaction force sensor 100 is detachably connected to one end of the suction device 101 via threaded connectors such as studs. The suction device 101 is slidably mounted on the connector 102. The brain contact interaction force sensor 100 measures the contact force between the suction device 101 and the brain tissue. The connector 102 is then connected to the overall suction and water injection end platform. Figure 7 The diagram shows the assembly structure of the brain contact interaction force sensor 100 and the electrocoagulation hemostasis forceps 202 in this embodiment. The first end of the outer shell 1 of the brain contact interaction force sensor 100 is detachably mounted to the top of the connector 201 by screws. The instrument connector 2 of the brain contact interaction force sensor 100 is detachably connected to the top of the electrocoagulation hemostasis forceps 202 by threaded connectors such as studs. The contact force between the electrocoagulation hemostasis forceps 202 and the brain tissue is measured by the brain contact interaction force sensor 100. The connector 201 is also connected to the overall hemostasis end platform.

[0028] The working principle of the brain-contact interaction force sensor 100 described above is as follows: Figure 5 As shown, the neurosurgical instrument is first fixedly connected to the connector threaded hole 22 of the instrument connector 2. When the instrument contacts brain tissue, the reaction force on the instrument is transmitted from the instrument connector 2 to the head of the thrust pin 4. Since the thrust pin 4 is in direct contact with and fixedly connected to the flexible tube 3, and the flexible groove segment 33 of the flexible tube 3 has low stiffness, the flexible tube 3 and the grating part on the circumferential optical fiber 5 attached inside it will be stretched and undergo elastic deformation. At this time, the center wavelength of the circumferential optical fiber 5 changes, and the contact force on the instrument can be obtained by the change in wavelength. When the instrument is subjected to force... Fz When fully aligned along the axis of the flexible circular tube 3, the circumferential optical fiber 5 is stretched entirely along the axial direction. During actual surgery, the force exerted on the instrument will inevitably deviate somewhat; when the circumferential optical fiber 5 is subjected to a radial horizontal force... FxyAt this time, the flexible circular tube 3 undergoes bending deformation. One side of the tube wall is under tension, while the other side is under compression. Since the three circumferential optical fibers 5 are arranged at different positions around the circumference, the magnitude and direction of the radial horizontal force can be determined through the differential signal between the circumferential optical fibers 5. Simultaneously, the sensor is also subjected to torsion around its axis. Mz At this point, the flexible groove segment 33 undergoes relative circumferential deformation, and the thin-walled connection area between the flexible groove segments 33 experiences torsional shear and local tensile deformation, causing different circumferential strains in the force-measuring fibers at different circumferential positions. The magnitude of the torsional torque on the sensor can be calculated using this combined strain signal. Meanwhile, the temperature-measuring grating on the central fiber 6 is isolated from the main force path, and its wavelength drift is used for the temperature drift of the step-size force-measuring fiber.

[0029] therefore, Fz , Fxy , Mz None of the measurements were obtained through a single optical fiber, but rather through a combined calculation of the wavelength drift of three circumferential force-measuring optical fibers 5. To achieve decoupling of the three loads, the sensor needs to be calibrated before use. During calibration, known magnitudes of loads are applied to the sensor. Fz , Fxy , Mz The center wavelength variation values ​​of the three circumferential optical fibers 5FBG were recorded. Let the wavelength drift of the three circumferential optical fibers 5 after temperature compensation be respectively... Δλ1′ , Δλ2′ and Δλ3′ Then, the following linear mapping relationship can be established between the output of FBG and the three loads:

[0030] in, s ij The sensitivity coefficients obtained through calibration are represented by this sensitivity matrix, which reflects the effects of axial force, radial horizontal force, and torsional torque around the axis on the wavelengths of the three force-measuring FBGs.

[0031] During actual measurement, the demodulator acquires the center wavelength drift of the three force-measuring fiber optic FBGs and uses the output of the temperature-measuring fiber optic FBG for temperature compensation to obtain... Δλ1′ , Δλ2′ and Δλ3′ Subsequently, the control module performs inverse calculations based on the pre-calibrated sensitivity matrix to obtain the three types of loads experienced by the sensor:

[0032] in, [S] -1The sensitivity matrix is ​​the decoupling matrix obtained by the least squares method. This method can separate the mixed wavelength of the three force-measuring optical fibers (FBGs) into axial force, radial force, and torsional torque around the axis, thereby realizing three-dimensional force detection.

[0033] Example 2 This embodiment provides a force sensing system for a neurosurgical robot. The system includes the aforementioned brain-contact interaction force sensor 100, an optical fiber, an FBG demodulator, a temperature compensation and force decoupling module, and a robot control and force feedback module; wherein: The optical fiber is connected to the central optical fiber 6 and the circumferential optical fiber 5 of the brain-contact interaction force sensor 100, and is used to transmit the optical signals of the central optical fiber 6 and the circumferential optical fiber 5 to the FBG demodulator. The FBG demodulator is used to acquire the center wavelength changes of the central optical fiber 6 and the circumferential optical fiber 5. The temperature compensation and force decoupling module is used to perform temperature compensation on each circumferential optical fiber 5 according to the output of the central optical fiber 6, and calculates the axial force, radial force and torsional torque using the decoupling matrix. The robot control and force feedback module is used to adjust the movement of the surgical robot or provide force feedback to the operator according to the calculation results of the temperature compensation and force decoupling module.

[0034] The surgical instruments for craniocerebral surgery come into contact with the brain tissue and generate an external load. The external load is transmitted to the brain contact interaction force sensor 100. Subsequently, the fiber optic FBG wavelength drift signal caused by the force is transmitted through the fiber optic cable to the FBG demodulator. The FBG demodulator collects the center wavelength changes of the force-measuring fiber optic FBG and the temperature-measuring fiber optic FBG and transmits the wavelength data to the temperature compensation and force decoupling module. The force data obtained by the module is finally transmitted to the robot control and force feedback module to adjust the movement and operation of the surgical robot.

[0035] Example 3 This embodiment provides an application of the above-mentioned force sensing system for neurosurgical robots. This force sensing system is used to monitor the contact force between surgical instruments and brain tissue in real time during craniocerebral surgery, and to control the surgical instruments based on the contact force.

[0036] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope of the invention. Therefore, if these modifications and variations fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

[0037] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A brain-based contact interaction force sensor based on FBG, characterized in that, It includes a housing, an instrument connector, a flexible cylindrical tube, a thrust pin, a circumferential optical fiber, and a central optical fiber; the housing, the instrument connector, the flexible cylindrical tube, and the thrust pin are all coaxially arranged; the flexible cylindrical tube and the thrust pin are installed inside the housing; The outer shell is a cylindrical hollow structure, and has a first end and a second end along its axial direction; The instrument connector is a disc-shaped structure and is located at the second end of the outer shell; The flexible circular tube is sleeved on the outer periphery of the thrust pin, with one end fixedly connected to the second end of the outer shell and the other end fixedly connected to the thrust pin; a flexible groove segment capable of elastic deformation under stress is provided in the middle of the flexible circular tube; three circumferential optical fibers are evenly distributed along the inner wall of the flexible circular tube; both ends of the circumferential optical fibers are fixedly installed on the inner wall of the flexible circular tube; the grating section of the circumferential optical fiber is positioned opposite to the flexible groove segment; the circumferential optical fiber is used to measure the strain caused by external force. One end of the thrust pin abuts against the inside of the first end of the outer shell, and the other end is fixedly connected to the instrument connector; the thrust pin is provided with a thrust pin center hole and a groove in the middle; the central optical fiber is fixedly installed in the thrust pin center hole of the thrust pin; the grating section of the central optical fiber is opposite to the groove; the central optical fiber is used for temperature compensation of the circumferential optical fiber.

2. The brain-contact interactive force sensor as described in claim 1, characterized in that, The flexible circular tube is made of stainless steel tube by machining, and its inner wall is provided with optical fiber bonding grooves that correspond one-to-one with the two ends of the circumferential optical fiber and are shaped to fit it; the wall thickness of the flexible groove segment is less than the wall thickness of the rest of the flexible circular tube. Both ends of the circumferential optical fiber are fixed in the optical fiber bonding groove and cured with UV adhesive.

3. The brain-contact interactive force sensor as described in claim 2, characterized in that, The outer shell is provided with a central hole, and a shell positioning protrusion is provided in the central hole at the second end; One end of the flexible tube is provided with a flexible segment positioning groove that corresponds one-to-one with the positioning protrusion of the outer shell and matches its shape. The flexible tube and the outer shell are fixed together by the corresponding positioning protrusion of the outer shell and the flexible segment positioning groove in a locking and bonding manner.

4. The brain-contact interactive force sensor as described in claim 3, characterized in that, A connector positioning protrusion is provided in the center hole of the instrument connector; The end of the thrust pin is provided with a thrust pin positioning groove that corresponds one-to-one with the positioning protrusion of the connector and fits in shape; the thrust pin and the instrument connector are fixed together by a set screw through the corresponding positioning protrusion of the connector and the positioning groove of the thrust pin.

5. The brain-contact interactive force sensor as described in claim 1, characterized in that, The two ends of the central optical fiber are installed in the center hole of the thrust nail by UV adhesive curing.

6. The brain-contact interactive force sensor as described in claim 1, characterized in that, The instrument connector is provided with a connector threaded hole; the connector threaded hole is used for threaded connection with neurosurgical instruments or end effectors.

7. The brain-contact interactive force sensor as described in claim 1, characterized in that, The first end of the housing is provided with a platform threaded hole, which is used for threaded connection with the end platform.

8. A force sensing system for a neurosurgical robot, characterized in that, Includes the brain-contact interaction force sensor, optical fiber, FBG demodulator, temperature compensation and force decoupling module, and robot control and force feedback module as described in any one of claims 1-7. The optical fiber is connected to the central optical fiber and the circumferential optical fiber of the brain contact interaction force sensor, and is used to transmit the optical signals of the central optical fiber and the circumferential optical fiber to the FBG demodulator. The FBG demodulator is used to collect the center wavelength changes of the central optical fiber and the circumferential optical fiber. The temperature compensation and force decoupling module is used to perform temperature compensation on each circumferential fiber according to the output of the central fiber, and to calculate the axial force, radial force and torsional moment using the decoupling matrix. The robot control and force feedback module is used to adjust the movement of the surgical robot or provide force feedback to the operator based on the calculation results of the temperature compensation and force decoupling module.

9. An application of the force sensing system for a neurosurgical robot as described in claim 8, characterized in that, It is used to monitor the contact force between surgical instruments and brain tissue in real time during craniocerebral surgery and to control the surgical instruments based on the contact force.

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