A three-dimensional force detection method for a metal additive-guided fiber-optic endogenous co-body clamp

Abstract

The invention proposes a three-dimensional force detection method for an optical fiber endogenous co-body clamp guided by metal additive, which belongs to the field of optical fiber sensing technology; the method comprises the following steps: preparing a three-dimensional force sensor, comprising a clamp head, an elastomer and a transmission component, wherein one end of the elastomer in the axial direction is connected to the clamp head, and the clamp head is used to clamp tissue; a transmission component is arranged at the other end of the elastomer in the axial direction; three groups of corroded step-reduced optical fiber Bragg gratings are centrally symmetrically distributed on the elastomer; when the clamp head of the three-dimensional force sensor clamps tissue, a mechanical model of the elastomer is constructed, and the relationship between the central wavelength drift of the corroded step-reduced optical fiber Bragg grating and temperature and the three-dimensional force is established to obtain a force and temperature sensitivity matrix; the central wavelengths of the three groups of corroded step-reduced optical fiber Bragg gratings are numerically decoupled to measure the three-dimensional force and temperature; a long short-term memory neural network LSTM is used to train network parameters; and the type of tissue clamped by the clamp is classified and output by a random forest algorithm.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber sensing technology, and in particular to a three-dimensional force detection method of an optical fiber endogenous co-body clamp guided by metal additive. Background Art

[0002] During robot-assisted minimally invasive surgery, the doctor's field of vision is limited by the size of the incision, and the doctor loses the tactile sense of the patient's tissue, making it impossible to evaluate the characteristics of the patient's tissue, resulting in excessive force causing trauma to the patient's tissue, affecting the natural course of the surgery, and causing intraoperative and postoperative complications. Existing force sensors are mostly electrical sensors, which are relatively mature in development, but have shortcomings such as limited sensitivity, electromagnetic interference and cross interference, and poor environmental adaptability.

[0003] In recent years, additive manufacturing technology has shown great potential in the processing and manufacturing of fiber optic sensors. The main advantages of this technology are that it can realize the manufacture of complex structures and can seamlessly switch between multiple materials. Through this technology, elastomers can be integrated with sensitive elements to manufacture more miniaturized sensors.

[0004] Therefore, based on the above situation, it is very necessary to provide a three-dimensional force detection method for a metal additive-guided optical fiber endogenous co-clamp that is smaller in size, flexible in operation, and can simultaneously decouple and fault-tolerantly measure three-dimensional force and temperature, in order to reduce accidental trauma, surgical pain and complications. Summary of the invention

[0005] In view of this, the present invention proposes a three-dimensional force detection method for a metal additive-guided optical fiber endogenous co-existing clamp with a certain fault tolerance, which can synchronously measure the three-dimensional force and temperature of the clamp end during surgery.

[0006] The present invention provides a three-dimensional force detection method of a metal additive-guided optical fiber endogenous co-body clamp, comprising the following steps:

[0007] S1: A three-dimensional force sensor is prepared in advance, wherein the three-dimensional force sensor comprises a clamp head, an elastic body and a transmission component, wherein one end of the elastic body in the axial direction is connected to the clamp head, and the clamp head is used to clamp tissue; a transmission component is provided at the other end of the elastic body in the axial direction, and the transmission component passes through the elastic body and is transmission-connected to the clamp head; and three groups of etched step-reduced fiber Bragg gratings are centrally symmetrically distributed on the elastic body;

[0008] S2: When the clamp head of the three-dimensional force sensor clamps the tissue, a mechanical model of the elastic body is constructed to obtain the strain of the elastic body under the action of the three-dimensional force. Combined with the temperature sensitivity coefficients of the three groups of corroded step-reduced fiber Bragg gratings, the relationship between the central wavelength drift of the corroded step-reduced fiber Bragg gratings and the temperature and three-dimensional force is established to obtain the force and temperature sensitivity matrix;

[0009] S3: By solving the generalized inverse matrix of the force and temperature sensitivity matrix as the calibration matrix, the three-dimensional force and temperature are measured by numerically decoupling the central wavelength of three groups of corroded step-reduced fiber Bragg gratings;

[0010] S4: Filter the three-dimensional force time series data and construct training samples, and use the long short-term memory neural network LSTM to train network parameters; after the training is completed, according to the samples corresponding to the current input three-dimensional force data, combined with the historical fault-free three-dimensional force data and the fault-free three-dimensional force data before the current moment, the three-dimensional force data at the current moment is predicted and the subsequent interactive force measurement data is restored, so as to realize the fault-tolerant output of three-dimensional force decoupling under the corrosion step-reduced fiber Bragg grating fault;

[0011] S5: Combining the central wavelength drift information of the three groups of corroded step-reduced fiber Bragg gratings, the type of tissue clamped by the clamp is classified and output through the random forest algorithm.

[0012] On the basis of the above technical scheme, preferably, the elastic body comprises a hollow double-layer cylinder, two diaphragms and a plurality of arc-shaped connecting parts; an inner cylinder is coaxially arranged at the center of the inner part of the outer cylinder of the double-layer cylinder, and the two ends of the inner cylinder extending axially are respectively fixedly connected to the two ends of the outer cylinder extending axially; an axially penetrating first through hole is arranged at the center of the end of the outer cylinder, and the first through hole is connected to the interior of the inner cylinder; a plurality of penetrating second through holes are arranged on the end surface between the inner surface of the outer cylinder and the outer surface of the inner cylinder, and the second through holes extend along the axial direction of the outer cylinder and are arranged through; the plurality of second through holes are arranged symmetrically with respect to the first through hole;

[0013] The two diaphragms are arranged at intervals on the outside of the end portion of the outer cylinder extending axially, and are arranged at intervals with the outer cylinder. A third through hole is arranged at the center of the two diaphragms, and a plurality of optical fiber fixing holes are also arranged at the edges of the two diaphragms. The optical fiber fixing holes are arranged through along the axial direction of the outer cylinder on the one hand, and extend outward along the radial direction of the diaphragm on the other hand; the third through hole is connected to the first through hole; the plurality of second through holes are connected to the plurality of optical fiber fixing holes in a one-to-one correspondence; the diameter of the two diaphragms is equivalent to the diameter of the outer cylinder;

[0014] A plurality of arc-shaped connecting parts are arranged between the end surfaces of the two diaphragms and the outer cylinder, the arc-shaped connecting parts are fixedly connected to the two diaphragms and the outer cylinder respectively, one end of the arc-shaped connecting part close to the outer cylinder is tangent to the contour of the second through hole, and one end of the arc-shaped connecting part away from the outer cylinder is flush with the edge of the optical fiber fixing hole; the inner surfaces of the plurality of arc-shaped connecting parts are located on the same virtual cylinder, the virtual cylinder is coaxially arranged with the inner cylinder, and the diameter of the virtual cylinder is larger than the first through hole, and the diameter of the virtual cylinder is smaller than the inner diameter of the outer cylinder;

[0015] The transmission component passes through the first through hole and the third through hole in sequence and is connected to the clamp head in transmission; three groups of corroded step-reduced fiber gratings pass through the fiber fixing hole and the second through hole, and the step-reduced fiber gratings between the two diaphragms are in a suspended tensioned state, and the length of the suspended tensioning section of the step-reduced fiber grating is the same as the axial length of the outer cylinder.

[0016] Preferably, the three groups of corroded step-reduced fiber gratings all include metallized optical fibers, on which a grating region is arranged, the grating region includes a normal segment and a corroded step-reduced segment arranged in sequence; metal nickel-plated layers are arranged at intervals at both ends of the grating region in the axial extension direction, and the metal nickel-plated layers are fixedly connected to the inner surface of the optical fiber fixing hole.

[0017] Further preferably, the preparation method of the elastomer is: an outer cylinder, an inner cylinder, two diaphragms and a plurality of arc-shaped connecting parts are processed by an additive manufacturing method of printing titanium alloy powder, half of each second through hole and optical fiber fixing hole is reserved, and then the corroded step-reduced fiber grating is placed in the corresponding half of the second through hole and optical fiber fixing hole, and then a complete second through hole and optical fiber fixing hole are prepared by laser scanning and printing titanium alloy powder to fix the corroded step-reduced fiber grating, and then three groups of corroded step-reduced optical fiber gratings and transmission components are sequentially inserted into the elastomer.

[0018] Further preferably, the specific content of step S2 is:

[0019] The three-dimensional force sensor is subjected to axial force F z, lateral force F X , longitudinal force F y and the influence of temperature;

[0020] When the three-dimensional force sensor is subjected to only axial force F When z acts, the strain of the suspended tension section of the three groups of corroded step-reduced fiber Bragg gratings is: ; then the elastic body is only subjected to axial force F When z acts, the wavelength drift corresponding to the normal section and the corroded step-reduced section of the three groups of corroded step-reduced fiber gratings is: ,in and are the center wavelength drifts of the normal section and the corroded step-reduced section of the suspended tensioned corroded step-reduced fiber Bragg grating, and are the initial center wavelengths of the normal section and the corroded step-reduced section of the suspended tensioned corroded step-reduced fiber Bragg grating, ; C is the strain sensitivity ratio between the normal section and the corroded step-reduced section of the corroded step-reduced fiber Bragg grating; and The elastic body is only subjected to axial force F The force sensitivity of the normal section and the corroded step-reduced section of the corroded step-reduced fiber Bragg grating under the action of z; is the effective elastic-optical coefficient of the optical fiber core;

[0021] When the 3D force sensor is subjected to only lateral force F X When the elastic body is acted upon, the elastic body undergoes lateral deformation, and the three groups of corroded step-reduced fiber gratings are named as the first corroded step-reduced fiber grating, the second corroded step-reduced fiber grating and the third corroded step-reduced fiber grating respectively; the first corroded step-reduced fiber grating undergoes deformation in the opposite direction to the second corroded step-reduced fiber grating, and the deformation of the second corroded step-reduced fiber grating is half of the deformation of the first corroded step-reduced fiber grating; the second corroded step-reduced fiber grating undergoes deformation equal in size and direction to the third corroded step-reduced fiber grating, satisfying ,in is the deformation of the first corrosion step-reduced fiber Bragg grating. is the deformation of the second corrosion step-reduced fiber Bragg grating. is the deformation of the third etched step-reduced fiber Bragg grating; therefore, when the elastic body is only subjected to lateral force F X When the effect is applied, the wavelength drift corresponding to the normal section and the corroded step-reduced section of the three groups of corroded step-reduced fiber gratings is: ,in and The elastic body is only subjected to lateral force F X Force sensitivity of the normal section and the corroded step-reduced section of the corroded step-reduced fiber Bragg grating during action;

[0022] When the three-dimensional force sensor is subjected to only longitudinal force F y When the force acts, the elastic body undergoes longitudinal deformation, the first corroded step-reduced fiber Bragg grating is located on the neutral layer, and the second corroded step-reduced fiber Bragg grating undergoes deformation equal to that of the third corroded step-reduced fiber Bragg grating in the opposite direction, so that the second corroded step-reduced fiber Bragg grating and the third corroded step-reduced fiber Bragg grating are longitudinally deformed. Fy The deformation that occurs during the action is and , the elastic body is only subjected to longitudinal force F y When the effect is applied, the wavelength drift corresponding to the normal section and the corroded step-reduced section of the three groups of corroded step-reduced fiber gratings is: ,in and The elastic body is only subjected to longitudinal force F y Force sensitivity of the normal section and the corroded step-reduced section of the corroded step-reduced fiber Bragg grating during action;

[0023] When the ambient temperature changes, the central wavelength of the optical fiber will drift due to the thermo-optic effect, thermal expansion effect and elastic-optic effect caused by internal thermal stress. Under the influence of temperature, the wavelength drifts corresponding to the normal section and the corroded step-reduced section of the three groups of corroded step-reduced fiber Bragg gratings are: ,in and is the wavelength drift of the normal section and the corroded step-reduced section of the three groups of corroded step-reduced fiber Bragg gratings under the action of temperature; the relative temperature sensitivity coefficient of the corroded step-reduced fiber Bragg grating is , is the thermo-optical coefficient of the corroded step-reduced fiber Bragg grating, is the linear thermal expansion coefficient of the corroded step-reduced fiber Bragg grating; and They are the temperature sensitivities of the normal section and the corroded step-reduced section of each corroded step-reduced fiber Bragg grating when the elastic body is only affected by temperature;

[0024] Combining the above-mentioned cases where force and temperature act alone, the relationship matrix between the center wavelength drift of the three groups of corroded step-reduced fiber Bragg grating reflection spectra and the three-dimensional force and temperature is obtained as follows: ,in is the center wavelength drift of the normal section and the corroded step-reduced section of each corroded step-reduced fiber Bragg grating, is the force and temperature sensitivity matrix.

[0025] More preferably, the content of step S3 is: by solving the sensitivity matrix The generalized inverse matrix of As the calibration matrix, the center wavelength drift of the normal section and the corroded step-reduced section of each corroded step-reduced fiber Bragg grating is calculated. Solve for 3D forces and temperature: .

[0026] Further preferably, the content of step S4 is: using the Kalman filtering method to filter the three-dimensional force time series data of the historically measured three-dimensional force sensor, and normalizing the filtered three-dimensional force time series data; dividing the normalized three-dimensional force time series data into a training set and a test set, wherein the training set is used to establish the model, and the test set is used to verify the generalization ability of the model; constructing training samples by sliding the time window, building an LSTM neural network model, and using the training set to train the parameters of the LSTM neural network model.

[0027] Further preferably, the content of step S5 is: using a random forest algorithm to classify the tissue clamped by the clamp head, using the three-dimensional force obtained by decoupling calculation as the input set of the random forest algorithm, and using the tissue category as the output. During the training process of the random forest algorithm, the number of decision trees is set to 100, the minimum number of leaves is 1, and the number of candidate features for feature selection of each tree is 2. 70% of the input set is used as a training set, and the remaining 30% of the input set is used as a test set to verify the trained random forest algorithm.

[0028] Further preferably, the diameter of the corroded step-reduced fiber Bragg grating is 125 μm, the length of the grating region is 3 mm, and the normal section and the corroded step-reduced section each include half of the grating region.

[0029] The three-dimensional force detection method of the metal additive-guided optical fiber endogenous co-body clamp provided by the present invention has the following beneficial effects compared with the prior art:

[0030] (1) The three-dimensional force and temperature can be measured by setting up an elastic sensing module. The reduced-diameter fiber Bragg grating is used as a sensing element to make the overall structure of the sensor more compact, which can eliminate the influence of temperature changes on the measurement accuracy and has good anti-electromagnetic interference performance. The self-enclosed structural design, the titanium alloy elastic metal material with both biocompatibility and corrosion resistance, and the packaging method combined with the additive manufacturing process make the sensor highly adaptable in tissue liquid erosion environment and high-temperature disinfection environment.

[0031] (2) Through the structural design of the double-layer diaphragm, the introduction of the reduced-diameter fiber Bragg grating, and the pre-tightening of the fiber Bragg grating to make it suspended, the sensor obtains extremely high sensitivity, making the force sensing module composed of the elastomer and three groups of corroded step-reduced-diameter fiber Bragg gratings more sensitive to changes in temperature and three-dimensional force;

[0032] (3) By introducing metal additive technology, the integrated manufacturing and packaging of the sensor clamp end, elastomer, integrated end, flexible metal tube and metallized reduced-diameter optical fiber can be realized. The corroded step-reduced-diameter optical fiber Bragg grating can be directly embedded in the 3D printing process, which can reduce creep and improve the overall stability and accuracy of the elastomer and the corroded step-reduced-diameter optical fiber Bragg grating. By measuring the force of the clamp wrist in situ, the force transmission path can be reduced, the disturbance of the optical fiber embedding can be reduced, and the accuracy and stability of the sensor can be improved.

[0033] (4) The corroded reduced-diameter fiber Bragg grating can provide the sensor with rich multi-channel central wavelength data. Combined with the long short-term memory neural network algorithm, the sensor is endowed with fault-tolerant measurement capabilities, further improving the reliability of the sensor. Even if one or two corroded step-reduced-diameter fiber Bragg gratings fail, the sensor can still be used reliably. By introducing the random forest algorithm, the tissues with different mechanical properties in the clamping process are classified and predicted, giving the sensor a wider range of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A three-dimensional diagram of a three-dimensional force sensor and a clamp as a whole for a three-dimensional force detection method of a metal additive-guided optical fiber endogenous co-body clamp of the present invention;

[0036] Figure 2 for Figure 1 A three-dimensional diagram of the explosion state;

[0037] Figure 3 A schematic diagram of an elastic body and a corroded step-reduced fiber Bragg grating of a three-dimensional force detection method of a metal additive-guided fiber endogenous co-body clamp of the present invention;

[0038] Figure 4 It is a schematic diagram of the extended-range manufacturing process of a three-dimensional force detection method of a metal additive-guided optical fiber endogenous co-body clamp of the present invention;

[0039] Figure 5 It is a spectrum diagram of a corroded step-reduced fiber Bragg grating embedded in an elastic body before and after being subjected to force in a three-dimensional force detection method of a metal additive-guided fiber endogenous co-body clamp of the present invention;

[0040] Figure 6 A data recovery flow chart of an LSTM network algorithm for a three-dimensional force detection method of a metal additive-guided optical fiber endogenous co-body clamp of the present invention;

[0041] Figure 7 This is a tissue recognition flow chart based on a random forest algorithm for a three-dimensional force detection method of a metal additive-guided optical fiber endogenous co-body clamp of the present invention.

[0042] Figure markings: 1. clamp head; 2. elastomer; 3. integrated end; 4. flexible metal tube; 5. nickel-titanium alloy wire; 6. pin hole; 7. corroded step-reduced fiber Bragg grating; 8. fiber fixing hole; 9. pin fixing hole; 10. clamp end; 11. diaphragm; 12. double-layer cylinder; 13. arc-shaped connecting part; 101. metal nickel-plated layer; 102-normal section; 103-corroded step-reduced section; 104-first corroded step-reduced fiber Bragg grating, 105-second corroded step-reduced fiber Bragg grating; 106-third corroded step-reduced fiber Bragg grating, 107-mother-and-child pins, 108-driving wire connector, 109-pin; 100, first through hole; 200, second through hole; 300, third through hole. DETAILED DESCRIPTION

[0043] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] like Figure 1 and Figure 2 As shown, the present invention provides a three-dimensional force detection method of a metal additive-guided optical fiber endogenous co-body clamp, comprising the following steps:

[0045] S1: A three-dimensional force sensor is prepared in advance. The three-dimensional force sensor includes a clamp head 1, an elastomer 2 and a transmission component. One end of the elastomer 2 in the axial direction is connected to the clamp head 1, and the clamp head 1 is used to clamp tissue; the other end of the elastomer 2 in the axial direction is provided with a transmission component, and the transmission component passes through the elastomer 2 and is connected to the clamp head 1 for transmission; three groups of corroded step-reduced fiber gratings 7 are centrally symmetrically distributed on the elastomer 2.

[0046] Figure 1The dotted box in the figure is a partially enlarged stereoscopic view, AA-direction cross-section view and BB-direction cross-section view of the elastic body 2. One end of the elastic body 2 has a clamp end 10 extending outward, and the clamp end is used to connect with the clamp head 1; the transmission component includes a flexible metal tube 4, a nickel-titanium alloy wire 5, a pin fixing hole 9, a drive wire connector 108, and a pin 109. The other end of the elastic body 2 has an integrated end 3 extending outward, which is used to assemble the transmission component. The integrated end 3 is provided with a flexible metal tube 4 and a nickel-titanium alloy wire 5; the clamp head 1 is a single-opening design, and two different pin fixing holes 9 and a drive wire connector 108 are arranged in the clamp head 1. The pin is fixed to the clamp end 10 by using laser welding technology to improve the reliability of the structure. The end of the drive wire connector 108 is provided with a nickel-titanium alloy wire fixing hole, and the nickel-titanium alloy wire 5 passes through the flexible metal tube 4 and the elastic body 2 in sequence, and one end is embedded in the end portion and embedded in the nickel-titanium alloy wire fixing hole, which improves the structural strength and simplifies the installation process. The main part of the transmission component of the three-dimensional force sensor can be installed by only two parent and child pins 107 and pin 109 in conjunction with the pin hole 6. The movable part of the clamp head is hinged to the fixed part through the pin, and is also fixed to the nickel-titanium alloy wire 5 through the pin, thereby realizing the opening and closing holding function of the clamp head.

[0047] like Figure 1 Combination Figure 2 and Figure 3 As shown, Figure 1 The AA and BB cross-sectional views show that the elastomer 2 includes a hollow double-layer cylinder 12, two diaphragms 11 and a plurality of arc-shaped connecting parts 13; an inner cylinder is coaxially arranged at the center of the outer cylinder of the double-layer cylinder 12, and the two axially extending ends of the inner cylinder are respectively fixedly connected to the two axially extending ends of the outer cylinder; an axially through first through hole 100 is arranged at the center of the end of the outer cylinder, and the first through hole 100 is connected to the interior of the inner cylinder; a plurality of through second through holes 200 are opened on the end surface between the inner surface of the outer cylinder and the outer surface of the inner cylinder, and the second through holes 200 extend along the axial direction of the outer cylinder and are arranged through; the plurality of second through holes 200 are arranged in a centrally symmetrical manner relative to the first through hole 100.

[0048] The two diaphragms 11 are arranged at intervals on the outside of the axially extending end of the outer cylinder, and are arranged at intervals from the outer cylinder. A third through hole 300 is arranged at the center of the two diaphragms 11. A plurality of optical fiber fixing holes 8 are also arranged at the edges of the two diaphragms 11. The optical fiber fixing holes 8 are arranged along the axial direction of the outer cylinder on the one hand, and extend outward along the radial direction of the diaphragm 11 on the other hand. The third through hole 300 is interconnected with the first through hole 100; a plurality of second through holes 200 are arranged in one-to-one correspondence with a plurality of optical fiber fixing holes 8. The diameter of the two diaphragms 11 is equivalent to the diameter of the outer cylinder. The structure of the double-layer cylinder 12 can be used to connect the nickel-titanium alloy wire and protect the optical fiber from being eroded by tissue fluid. The structure of the two diaphragms 11 can improve the axial force sensitivity of the three-dimensional force sensor.

[0049] A plurality of arc-shaped connecting portions 13 are arranged between the two diaphragms 11 and the end faces of the outer cylinder, and the arc-shaped connecting portions 13 are fixedly connected to the two diaphragms 11 and the outer cylinder respectively, and one end of the arc-shaped connecting portion 13 close to the outer cylinder is tangent to the contour of the second through hole 200, and one end of the arc-shaped connecting portion 13 away from the outer cylinder is flush with the edge of the optical fiber fixing hole 8; the inner surfaces of the plurality of arc-shaped connecting portions 13 are located on the same virtual cylinder, and the virtual cylinder is coaxially arranged with the inner cylinder, and the diameter of the virtual cylinder is larger than the first through hole 100, and the diameter of the virtual cylinder is smaller than the inner diameter of the outer cylinder. Figure 3 In the schematic diagram below, the central axes of the second through holes 200 are also distributed on a dotted circle. is the radius of the dotted circle, ie, the distance from the first through hole 100 to the second through hole 200 .

[0050] The transmission component passes through the first through hole 100 and the third through hole 300 in sequence and is connected to the clamp head 1 in transmission; three groups of corroded step-reduced fiber Bragg gratings 7 pass through the fiber fixing hole 8 and the second through hole 200, and the step-reduced fiber Bragg gratings between the two diaphragms 11 are in a suspended tensioned state, and the length of the suspended tensioned section of the step-reduced fiber Bragg gratings is the same as the axial length of the outer cylinder.

[0051] The three groups of corroded step-reduced fiber gratings 7 all include metalized optical fibers, on which a grating area is provided, and the grating area includes a normal section 102 and a corroded step-reduced section 103 arranged in sequence; metal nickel-plated layers 101 are arranged at intervals at both ends of the grating area in the axial extension direction, and the metal nickel-plated layers 101 are fixedly connected to the inner surface of the optical fiber fixing hole 8. The fixed part of the corroded step-reduced fiber grating 7 and the elastic body 2 is metalized with the metal nickel-plated layer 101 to protect the optical fiber grating so that it can be embedded in the elastic body 2 in a tensioned and suspended manner. The normal section of the corroded step-reduced fiber grating 7 is indicated by 102, and the corroded step-reduced section is indicated by 103. The three groups of corroded step-reduced fiber gratings 7 are named as the first corroded step-reduced fiber grating 104, the second corroded step-reduced fiber grating 105, and the third corroded step-reduced fiber grating 106.

[0052] As a preferred embodiment, the diameter of the corroded step-reduced fiber grating 7 is 125 μm, the length of the grating area is 3 mm, and the normal section and the corroded step-reduced section each contain half of the grating area. The first corroded step-reduced fiber grating 104, the second corroded step-reduced fiber grating 105 and the third corroded step-reduced fiber grating 106 are all evenly distributed around the circumference parallel to the central axis of the elastomer, and the angle between the central axes of adjacent corroded step-reduced fiber gratings is 120°, which can prevent fiber chirping, improve the mechanical properties of the three-dimensional force sensor, and reduce the repeatability error of the three-dimensional force sensor.

[0053] Reference Figure 4 As shown, the preparation method of the elastomer 2 is as follows: the outer cylinder, the inner cylinder, the two diaphragms 11 and the plurality of arc-shaped connecting parts 13 are processed by the additive manufacturing method of printing titanium alloy powder, half of each second through hole 200 and the optical fiber fixing hole 8 are reserved, and then the corroded step-reduced fiber grating 7 is placed in the corresponding half of the second through hole 200 and the optical fiber fixing hole 8, and then the complete second through hole 200 and the optical fiber fixing hole 8 are prepared by laser scanning and printing titanium alloy powder to fix the corroded step-reduced fiber grating 7, and then three groups of corroded step-reduced fiber gratings 7 and transmission components are sequentially inserted on the elastomer 2. That is, the printing method from bottom to top is adopted, and when printing to the first through hole 100, the second through hole and the third through hole 300, the printing is temporarily stopped so as to place the corroded step-reduced fiber grating 7 and the nickel-titanium alloy wire 5. During the printing process, the curing process of the metal nickel-plated layer 101 and the diaphragm of the corroded step-reduced fiber grating 7 can be completed. Figure 4 The metallized optical fiber marked in the figure refers to the corroded step-reduced optical fiber Bragg grating 7 having a metal nickel-plated layer 101 . Figure 5 The optical spectrum of the corroded step-reduced fiber Bragg grating embedded in the elastic body before and after the force is applied. When the corroded step-reduced fiber Bragg grating embedded in the elastic body is subjected to the same external force, the central wavelengths of the normal section 102 and the corroded step-reduced section 103 of the grating area will produce two different offsets.

[0054] Similarly, the clamp end 10, the clamp head 1, the drive wire connector 108, the elastomer 2 and the integrated end 3 are manufactured by additive manufacturing technology, and the material is titanium alloy. The three-dimensional force sensor manufactured in this way has good biocompatibility.

[0055] S2: When the clamp head 1 of the three-dimensional force sensor clamps the tissue, a mechanical model of the elastomer 2 is constructed to obtain the strain of the elastomer 2 under the action of the three-dimensional force. Combined with the temperature sensitivity coefficients of the three groups of corroded step-reduced fiber Bragg gratings 7, the relationship between the central wavelength drift of the corroded step-reduced fiber Bragg grating 7 and the temperature and three-dimensional force is established to obtain the force and temperature sensitivity matrix.

[0056] The specific content of step S2 is:

[0057] The three-dimensional force sensor is subjected to axial force F z, lateral force F X , longitudinal force F y and temperature influence.

[0058] When the force acts, the two sections of the corroded step-reduced fiber Bragg grating 7 produce different degrees of strain. Combining material mechanics, it can be known that the strain values ​​of the normal section 102 and the corroded step-reduced section 103 under the force should satisfy: ,in For the The strain generated by the suspended tensioned corroded step-reduced fiber Bragg grating 7, and Indicates The strain of the normal section 102 and the corroded step-reduced diameter section 103 of the suspended tensioned corroded step-reduced diameter fiber grating 7, .

[0059] When the three-dimensional force sensor is subjected to only axial force F When z acts, the elastic body 2 undergoes axial deformation, and the tensile and compressive deformation of the elastic body 2) is obtained by combining structural mechanics: ,in is the axial length of the outer cylinder, is the axial length of the arc-shaped connecting portion 13, It is the thickness of the outer cylinder excluding the closed areas at both ends. is the axial length of the normal section 102 of the corroded step-reduced fiber Bragg grating 7, is the axial length of the etched step-reduced fiber Bragg grating 7, and are the elastic modulus of the elastic body 2 and the elastic modulus of the corroded step-reduced fiber Bragg grating 7, respectively. is the radial cross-sectional area of ​​the arc-shaped connecting portion 13, is the cross-sectional area of ​​the outer cylinder at the non-end position, is the radial cross-sectional area of ​​the diaphragm 11, is the radial cross-sectional area of ​​the corroded step-reduced fiber Bragg grating 7, is the thickness of the diaphragm 11, is the elastic modulus of elastic body 2, is the radial cross-sectional area of ​​the elastic body 2.

[0060] Assume that the diaphragm is under axial force F Under the action of z, a small deflection occurs. Considering only the bending deformation in the vertical direction of the diaphragm, the bending differential equation in polar coordinates can be obtained: The bending stiffness of the diaphragm is , is the Poisson's ratio of the diaphragm 11; applied load ;, is the boundary size of the membrane 11, and the boundary conditions are substituted: , the maximum deflection generated at the center of the diaphragm is obtained , considering that there is a third through hole 300 at the center of the diaphragm, the boundary condition is: .

[0061] The maximum deflection of the diaphragm is obtained as: ,in is the outer diameter of the diaphragm 11; is the outer diameter of the elastic body 2 between the two diaphragms 11;

[0062] The elastic body 2 has a double-mode structure, and the outer cylinder and the inner cylinder generate a reaction force on the diaphragm 12. F z, the reaction force is obtained according to the minimum deformation theory F The maximum deflection of the diaphragm 11 under the action of z is: ;

[0063] Combining the above contents, we can get that the three-dimensional force sensor is only subjected to axial force F When z acts, the strains of the suspension tensioning sections of the three groups of corroded step-reduced fiber gratings 7 are all; ; then the elastic body 2 is only subjected to axial force F When z acts, the wavelength drift corresponding to the normal section and the corroded step-reduced section of the three groups of corroded step-reduced fiber gratings 7 is: ,in and are the center wavelength drifts of the normal section and the corroded step-reduced section of the suspended tensioned corroded step-reduced fiber grating 7, and are the initial center wavelengths of the normal section and the corroded step-reduced section of the suspended tensioned corroded step-reduced fiber Bragg grating 7; the strain sensitivity ratio of the normal section and the corroded step-reduced section of the corroded step-reduced fiber Bragg grating 7 ; and Elastic body 2 is only subjected to axial force F The force sensitivity of the normal section and the corroded step-reduced section of the corroded step-reduced fiber grating 7 when z acts; is the effective elastic-optical coefficient of the optical fiber core.

[0064] When the three-dimensional force sensor is subjected to lateral force F XWhen in action, the elastic body 2 undergoes lateral deformation, the first corroded step-reduced fiber Bragg grating 104 undergoes deformation in the opposite direction to the second corroded step-reduced fiber Bragg grating 105, and the deformation of the second corroded step-reduced fiber Bragg grating 105 is half of the deformation of the first corroded step-reduced fiber Bragg grating 104; the second corroded step-reduced fiber Bragg grating 105 undergoes deformation equal in size and direction to the third corroded step-reduced fiber Bragg grating 106. Satisfy ,in is the deformation of the first etched step-reduced fiber Bragg grating 104, is the deformation of the second etched step-reduced fiber Bragg grating 105, This is the deformation of the fiber Bragg grating 106 caused by the third etched step-reduced diameter.

[0065] When the three-dimensional force sensor is subjected to lateral force F X When in action, the first arc-shaped connecting portion 13 of the elastic body 2 is x The displacement in the direction is: ,in and are the moments of inertia of the first arc-shaped connection portion 13 and the corroded step-reduced fiber Bragg grating 7 respectively; is the distance from the lateral force bearing point to the adjacent diaphragm;

[0066] When the three-dimensional force sensor is subjected to lateral force F X When the elastic body 2 is in action, the first diaphragm x The displacement in the direction is: ,in is the moment of inertia of the diaphragm;

[0067] When the three-dimensional force sensor is subjected to lateral force F X When in action, the double-layer cylinder 12 of the elastic body 2 is x The displacement in the direction is: ,in is the moment of inertia of the double-layer cylinder 12;

[0068] When the three-dimensional force sensor is subjected to lateral force F X When the second diaphragm of elastic body 2 is in x The displacement in the direction is: ;

[0069] When the three-dimensional force sensor is subjected to lateral force F X When in action, the first arc-shaped connecting portion 13 of the elastic body 2 is x The displacement in the direction is: .

[0070] According to the small deformation theory, the strain of the first suspended optical fiber can be obtained as :satisfy , Combining the above formula, we can get , and .

[0071] Therefore, the 3D force sensor is only subject to lateral forces. F X When the effect is applied, the wavelength drift corresponding to the normal section and the corroded step-reduced section of the three groups of corroded step-reduced fiber gratings 7 is: ,in and Elastic body 2 is only subjected to lateral force F X The force sensitivity of the normal section and the corroded step-reduced section of the corroded step-reduced fiber Bragg grating 7 during the action;

[0072] When the three-dimensional force sensor is subjected to only longitudinal force F y When the force acts, the elastic body 2 undergoes longitudinal deformation, the first corroded step-reduced fiber Bragg grating 104 is located on the neutral layer, and the second corroded step-reduced fiber Bragg grating 105 undergoes deformation equal to and opposite to the third corroded step-reduced fiber Bragg grating 106, so that the second corroded step-reduced fiber Bragg grating 105 and the third corroded step-reduced fiber Bragg grating 106 are longitudinally deformed. F y The deformation that occurs during the action is and .

[0073] .

[0074] The three-dimensional force sensor is only subjected to longitudinal force F y When the effect is applied, the wavelength drift corresponding to the normal section and the corroded step-reduced section of the three groups of corroded step-reduced fiber gratings 7 is: ,in and Elastic body 2 is only subjected to longitudinal force F y The force sensitivity of the normal section and the corroded step-reduced section of the corroded step-reduced fiber Bragg grating 7 during action.

[0075] When the ambient temperature changes, the central wavelength of the optical fiber will drift due to the thermo-optic effect, thermal expansion effect and elastic-optic effect caused by internal thermal stress. Under the influence of temperature, the wavelength drift corresponding to the normal section and the corroded step-reduced section of the three groups of corroded step-reduced optical fiber gratings 7 is: ,in and is the wavelength drift of the normal section and the corroded step-reduced section of the three groups of corroded step-reduced fiber Bragg gratings 7 under the action of temperature; the relative temperature sensitivity coefficient of the corroded step-reduced fiber Bragg grating 7 is , is the thermo-optical coefficient of the corroded step-reduced fiber Bragg grating 7, is the linear thermal expansion coefficient of the corroded step-reduced fiber Bragg grating 7; and are respectively the temperature sensitivities of the normal section and the corroded step-reduced section of each corroded step-reduced fiber grating 7 when the elastic body 2 is only affected by temperature;

[0076] Combining the above-mentioned cases where force and temperature act alone, the relationship matrix between the center wavelength drift of the reflection spectrum of three groups of corroded step-reduced fiber Bragg grating 7 and the three-dimensional force and temperature is obtained as follows: ,in is the center wavelength drift of the normal section and the corroded step-reduced section of each corroded step-reduced fiber grating 7, is the force and temperature sensitivity matrix.

[0077] S3: By solving the generalized inverse matrix of the force and temperature sensitivity matrix as a calibration matrix, the central wavelength of three groups of corroded step-reduced fiber Bragg gratings 7 is numerically decoupled to obtain the three-dimensional force and temperature.

[0078] The specific content is: By solving the sensitivity matrix The generalized inverse matrix of As a calibration matrix, the center wavelength drift of the normal section and the corroded step-reduced section of each corroded step-reduced fiber Bragg grating (7) is calculated. Solve for 3D forces and temperature: .

[0079] S4: Filter the three-dimensional force time series data and construct training samples, and use the long short-term memory neural network LSTM to train network parameters; after the training is completed, according to the samples corresponding to the current input three-dimensional force data, combined with the historical fault-free three-dimensional force data and the fault-free three-dimensional force data before the current moment, the three-dimensional force data at the current moment is predicted and the subsequent interactive force measurement data is restored to achieve the fault-tolerant output of three-dimensional force decoupling under the corrosion step-reduced fiber Bragg grating 7 fault.

[0080] The content of step S4 is: use the Kalman filter method to filter the three-dimensional force time series data of the three-dimensional force sensor measured historically, and normalize the filtered three-dimensional force time series data; divide the normalized three-dimensional force time series data into a training set and a test set, wherein the training set is used to establish the model, and the test set is used to verify the generalization ability of the model; construct training samples by sliding the time window, build an LSTM neural network model, and use the training set to train the parameters of the LSTM neural network model. Figure 6 As shown in the picture, it shows the flowchart of inputting the three-dimensional force time series data before the fault into the trained LSTM network algorithm to recover the three-dimensional force data at the current moment.

[0081] S5: combining the central wavelength drift information of the three groups of corroded step-reduced fiber gratings 7, classifying and outputting the type of tissue clamped by the clamp through a random forest algorithm.

[0082] The content of step S5 is: using the random forest algorithm to classify the tissue clamped by the clamp head 1, such as Figure 7 As shown, the diagram provides a flow chart of tissue recognition based on the random forest algorithm. The three-dimensional force obtained by decoupling calculation is used as the input set of the random forest algorithm, and the tissue category is used as the output. During the training process of the random forest algorithm, the number of decision trees is set to 100, the minimum number of leaves is 1, and the number of candidate features for feature selection of each tree is 2. 70% of the input set is used as the training set, and the remaining 30% of the input set is used as the test set to verify the trained random forest algorithm.

[0083] The above description is only a preferred 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 in the protection scope of the present invention.

Claims

1. A three-dimensional force detection method for a metal additive-guided fiber-optic endogenous co-body clamp. It is characterized in that The steps include: S1: A three-dimensional force sensor is prepared in advance, wherein the three-dimensional force sensor comprises a clamp head (1), an elastic body (2) and a transmission component, wherein one end of the elastic body (2) in the axial direction is connected to the clamp head (1), and the clamp head (1) is used to clamp tissue; the other end of the elastic body (2) in the axial direction is provided with a transmission component, and the transmission component passes through the elastic body (2) and is transmission-connected to the clamp head (1); and three groups of etched step-reduced fiber Bragg gratings (7) are centrally symmetrically distributed on the elastic body (2); S2: When the clamp head (1) of the three-dimensional force sensor clamps the tissue, a mechanical model of the elastic body (2) is constructed to obtain the strain of the elastic body (2) under the action of the three-dimensional force. Combined with the temperature sensitivity coefficients of the three groups of corroded step-reduced fiber Bragg gratings (7), the relationship between the central wavelength drift of the corroded step-reduced fiber Bragg gratings (7) and the temperature and three-dimensional force is established to obtain the force and temperature sensitivity matrix; S3: By solving the generalized inverse matrix of the force and temperature sensitivity matrix as the calibration matrix, the three-dimensional force and temperature are numerically decoupled from the central wavelength of three groups of corroded step-reduced fiber Bragg gratings (7); S4: Filter the three-dimensional force time series data and construct training samples, and use the long short-term memory neural network LSTM to train network parameters; After the training is completed, according to the sample corresponding to the currently input three-dimensional force data, combined with the historical fault-free three-dimensional force data and the fault-free three-dimensional force data before the current moment, the three-dimensional force data at the current moment is predicted and the subsequent interactive force measurement data is restored, so as to realize the fault-tolerant output of the three-dimensional force decoupling under the corrosion step-reduced fiber Bragg grating (7) fault; S5: Combining the central wavelength drift information of the three groups of corroded step-reduced fiber Bragg gratings (7), the type of tissue clamped by the clamp is classified and outputted using a random forest algorithm.

2. A three-dimensional force detection method for a metal additive-guided optical fiber endogenous co-body clamp according to claim 1, It is characterized in that The elastic body (2) comprises a hollow double-layer cylinder (12), two diaphragms (11) and a plurality of arc-shaped connecting parts; an inner cylinder is coaxially arranged at the center of the outer cylinder of the double-layer cylinder (12), and the two axially extending ends of the inner cylinder are respectively fixedly connected to the two axially extending ends of the outer cylinder; an axially penetrating first through hole (100) is arranged at the center of the end of the outer cylinder, and the first through hole (100) is communicated with the interior of the inner cylinder; a plurality of through second through holes (200) are opened on the end surface between the inner surface of the outer cylinder and the outer surface of the inner cylinder, and the second through holes (200) extend along the axial direction of the outer cylinder and are arranged through; the plurality of second through holes (200) are arranged in a centrally symmetrical manner relative to the first through hole (100); The two diaphragms (11) are arranged at intervals on the outside of the end portion of the outer cylinder extending axially and are arranged at intervals from the outer cylinder. A third through hole (300) is arranged at the center of the two diaphragms (11). A plurality of optical fiber fixing holes (8) are also arranged at the edges of the two diaphragms (11). The optical fiber fixing holes (8) are arranged to pass through along the axial direction of the outer cylinder on the one hand, and extend outward along the radial direction of the diaphragm (11) on the other hand. The third through hole (300) is connected to the first through hole (100). The plurality of second through holes (200) are connected to the plurality of optical fiber fixing holes (8) in a one-to-one correspondence. The diameter of the two diaphragms (11) is equivalent to the diameter of the outer cylinder. A plurality of arc-shaped connecting parts are arranged between the two diaphragms (11) and the end surface of the outer cylinder, the arc-shaped connecting parts are respectively fixedly connected to the two diaphragms (11) and the outer cylinder, one end of the arc-shaped connecting part close to the outer cylinder is tangent to the contour of the second through hole (200), and one end of the arc-shaped connecting part away from the outer cylinder is flush with the edge of the optical fiber fixing hole (8); the inner surfaces of the plurality of arc-shaped connecting parts are located on the same virtual cylinder, the virtual cylinder is coaxially arranged with the inner cylinder, and the diameter of the virtual cylinder is larger than the first through hole (100), and the diameter of the virtual cylinder is smaller than the inner diameter of the outer cylinder; The transmission component passes through the first through hole (100) and the third through hole (300) in sequence and is connected to the clamp head (1) in a transmission manner; three groups of etched step-reduced optical fiber Bragg gratings (7) pass through the optical fiber fixing hole (8) and the second through hole (200), and the step-reduced optical fiber Bragg gratings between the two diaphragms (11) are in a suspended tensioned state, and the length of the suspended tensioned section of the step-reduced optical fiber Bragg gratings is the same as the axial length of the outer cylinder.

3. A three-dimensional force detection method for a metal additive-guided optical fiber endogenous co-body clamp according to claim 2, It is characterized in that The three groups of corroded step-reduced fiber gratings (7) all comprise metalized optical fibers, on which a grating region is arranged, the grating region comprising a normal segment and a corroded step-reduced segment arranged in sequence; metal nickel-plated layers are arranged at intervals at both ends of the grating region in the axial extension direction, and the metal nickel-plated layers are fixedly connected to the inner surface of the optical fiber fixing hole (8).

4. A three-dimensional force detection method for a metal additive-guided optical fiber endogenous co-body clamp according to claim 3, It is characterized in that The preparation method of the elastomer (2) is as follows: an outer cylinder, an inner cylinder, two diaphragms (11) and a plurality of arc-shaped connecting parts are processed by an additive manufacturing method of printing titanium alloy powder, half of each second through hole (200) and optical fiber fixing hole (8) is reserved, and then a corroded step-reduced optical fiber Bragg grating (7) is placed in the corresponding half of the second through hole (200) and the optical fiber fixing hole (8), and then a complete second through hole (200) and optical fiber fixing hole (8) are prepared by laser scanning and printing titanium alloy powder to fix the corroded step-reduced optical fiber Bragg grating (7), and then three groups of corroded step-reduced optical fiber Bragg gratings (7) and transmission components are sequentially inserted into the elastomer (2).

5. The three-dimensional force detection method of the metal additive-guided optical fiber endogenous co-body clamp according to claim 3, It is characterized in that The specific content of step S2 is: The three-dimensional force sensor is subjected to axial force F z, lateral force F X , longitudinal force F y and the influence of temperature; When the three-dimensional force sensor is subjected to only axial force F When z acts, the strain of the suspended tension section of the three groups of corroded step-reduced fiber gratings (7) is: ; then the elastic body (2) is only subjected to axial force F When z acts, the wavelength drift corresponding to the normal section and the corroded step-reduced section of the three groups of corroded step-reduced fiber gratings (7) is: ,in and are the central wavelength drifts produced by the normal section and the corroded step-reduced section of the suspended tensioned corroded step-reduced fiber Bragg grating (7), and are the initial central wavelengths of the normal section and the corroded step-reduced section of the suspended tensioned corroded step-reduced fiber Bragg grating (7), ; C is the strain sensitivity ratio between the normal section and the corroded step-reduced diameter section of the corroded step-reduced diameter fiber Bragg grating (7); and The elastic body (2) is only subjected to axial force F The force sensitivity of the normal section and the corroded step-reduced section of the corroded step-reduced fiber Bragg grating (7) when z acts; is the effective elastic-optical coefficient of the optical fiber core; When the 3D force sensor is subjected to only lateral force F X When the elastic body (2) is in action, the elastic body (2) undergoes lateral deformation, and the three groups of corroded step-reduced fiber gratings (7) are named as the first corroded step-reduced fiber grating, the second corroded step-reduced fiber grating and the third corroded step-reduced fiber grating respectively; the first corroded step-reduced fiber grating undergoes deformation in the opposite direction to the second corroded step-reduced fiber grating, and the deformation of the second corroded step-reduced fiber grating is half of the deformation of the first corroded step-reduced fiber grating; the second corroded step-reduced fiber grating undergoes deformation of the same magnitude and direction as the third corroded step-reduced fiber grating, satisfying ,in is the deformation of the first corrosion step-reduced fiber Bragg grating. is the deformation of the second corrosion step-reduced fiber Bragg grating. is the deformation of the third etched step-reduced fiber Bragg grating; therefore, when the elastic body (2) is only subjected to lateral force F X When the effect is applied, the wavelength drift corresponding to the normal section and the corroded step-reduced section of the three groups of corroded step-reduced fiber gratings (7) is: ,in and The elastic body (2) is only subjected to lateral force F X Force sensitivity of a normal section and a corroded step-reduced section of the corroded step-reduced fiber Bragg grating (7) during action; When the three-dimensional force sensor is subjected to only longitudinal force F y When the force acts, the elastic body (2) undergoes longitudinal deformation, the first corroded step-reduced fiber grating is located on the neutral layer, and the second corroded step-reduced fiber grating undergoes deformation equal in magnitude and opposite in direction to the third corroded step-reduced fiber grating, so that the second corroded step-reduced fiber grating and the third corroded step-reduced fiber grating are longitudinally deformed. F y The deformation that occurs during the action is and , then the elastic body (2) is only subjected to longitudinal force F y When the effect is applied, the wavelength drift corresponding to the normal section and the corroded step-reduced section of the three groups of corroded step-reduced fiber gratings (7) is: ,in and The elastic body (2) is only subjected to longitudinal force F y Force sensitivity of a normal section and a corroded step-reduced section of the corroded step-reduced fiber Bragg grating (7) during action; When the ambient temperature changes, the central wavelength of the optical fiber will drift due to the thermo-optical effect, thermal expansion effect and elastic-optical effect caused by internal thermal stress. Under the influence of temperature, the wavelength drift corresponding to the normal section and the corroded step-reduced section of the three groups of corroded step-reduced optical fiber gratings (7) is: ,in and is the wavelength drift of the normal section and the corroded step-reduced section of the three groups of corroded step-reduced fiber Bragg gratings (7) under the action of temperature; the relative temperature sensitivity coefficient of the corroded step-reduced fiber Bragg grating (7) is , is the thermo-optical coefficient of the corroded step-reduced fiber Bragg grating (7), is the linear thermal expansion coefficient of the corroded step-reduced fiber Bragg grating (7); and are respectively the temperature sensitivities of the normal section and the corroded step-reduced section of each corroded step-reduced fiber grating (7) when the elastic body (2) is only affected by temperature; Combining the above-mentioned cases where force and temperature act alone, the relationship matrix between the center wavelength drift of the reflection spectrum of the three groups of corroded step-reduced fiber Bragg gratings (7) and the three-dimensional force and temperature is obtained as follows: ,in is the central wavelength drift of the normal section and the corroded step-reduced section of each corroded step-reduced fiber Bragg grating (7), is the force and temperature sensitivity matrix.

6. A three-dimensional force detection method for a metal additive-guided optical fiber endogenous co-body clamp according to claim 5, It is characterized in that The content of step S3 is: by solving the sensitivity matrix The generalized inverse matrix of As a calibration matrix, the center wavelength drift of the normal section and the corroded step-reduced section of each corroded step-reduced fiber Bragg grating (7) is calculated. Solve for 3D forces and temperature: .

7. A three-dimensional force detection method for a metal additive-guided optical fiber endogenous co-body clamp according to claim 6, It is characterized in that The content of step S4 is: use the Kalman filtering method to filter the three-dimensional force time series data of the historically measured three-dimensional force sensor, and normalize the filtered three-dimensional force time series data; divide the normalized three-dimensional force time series data into a training set and a test set, wherein the training set is used to establish the model, and the test set is used to verify the generalization ability of the model; construct training samples by sliding the time window, build an LSTM neural network model, and use the training set to train the parameters of the LSTM neural network model.

8. A three-dimensional force detection method for a metal additive-guided optical fiber endogenous co-body clamp according to claim 7, It is characterized in that The content of step S5 is: using the random forest algorithm to classify the tissue clamped by the clamp head (1), using the three-dimensional force obtained by decoupling calculation as the input set of the random forest algorithm, and using the tissue category as the output. During the training process of the random forest algorithm, the number of decision trees is set to 100, the minimum number of leaves is set to 1, the number of candidate features for feature selection of each tree is set to 2, 70% of the input set is used as the training set, and the remaining 30% of the input set is used as the test set, and the trained random forest algorithm is verified.

9. The three-dimensional force detection method of the metal additive-guided optical fiber endogenous co-body clamp according to claim 3, It is characterized in that The diameter of the corroded step-reduced optical fiber Bragg grating (7) is 125 μm, the length of the grating region is 3 mm, and the normal section and the corroded step-reduced section each contain half of the grating region.

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