Master-slave type interventional surgical robot force feedback system and method

Abstract

This invention provides a master-slave type interventional surgical robot force feedback system and method, relating to the field of fiber optic force sensing detection. The method includes a Y-valve rotation mechanism, a guidewire manipulation mechanism, and a balloon catheter manipulation mechanism disposed inside a housing. The guidewire manipulation mechanism is used to deliver or circumferentially rotate the guidewire; the balloon catheter manipulation mechanism is used to deliver the balloon catheter; the Y-valve rotation mechanism is connected to the end of the interventional force sensing catheter, which integrates a fiber optic force sensing module and has a bent front end. The Y-valve rotation mechanism is used to limit and retract the movement direction of the guidewire and balloon catheter into the interventional force sensing catheter, and to adjust the circumferential rotation direction of the interventional force sensing catheter so that when the interventional force sensing catheter is delivered into the blood vessel, it can collect the three-dimensional contact force generated by the contact between the catheter tip and the blood vessel wall, and adjust the orientation of the bent section of the interventional force sensing catheter tip to conform to the blood vessel wall.

Description

Technical Field

[0001] This invention relates to the field of fiber optic force sensing technology, and in particular to a master-slave type interventional surgical robot force feedback system and method. Background Technology

[0002] Cardiovascular diseases mainly include coronary atherosclerotic heart disease, myocardial infarction, vascular structural abnormalities, arrhythmias, and congenital heart malformations. In clinical treatment, drug therapy serves as the basic intervention, controlling disease progression by regulating blood lipids, inhibiting platelet aggregation, and improving myocardial oxygen supply. For patients with complex lesions, interventional therapy has become an important solution due to its minimally invasive advantages. Specific procedures include: establishing a microchannel (usually ≤3mm in diameter) through percutaneous puncture; under the guidance of digital subtraction angiography (DSA) or computed tomography (CT) three-dimensional imaging, precisely manipulating catheters, guidewires, and stent delivery systems to achieve precise intervention goals such as thrombus removal, stenosis dilation, or correction of malformations, thereby significantly reducing the tissue trauma and complication risks associated with traditional open-chest surgery.

[0003] In traditional percutaneous vascular interventional surgery, the surgeon first punctures the patient's femoral artery with a needle, then uses imaging data provided by angiography to guide the catheter and guidewire to the lesion site to perform treatments such as tissue ablation, plaque rotation atherectomy, and stent implantation. Because the surgeon is constantly exposed to X-ray radiation during the procedure, the risk of developing skin cancer, leukemia, thyroid cancer, and cataracts increases. While wearing a lead apron during surgery can reduce radiation absorption to some extent, it reduces the flexibility of the surgical procedure and increases the probability of orthopedic injuries to the surgeon.

[0004] However, interventional surgical robotic devices still face significant technical bottlenecks: delivery systems based on linear guide mechanisms are limited by short instrument delivery strokes and positioning deviations caused by mechanical deformation under gravity, making it difficult to maintain the coordinated movement accuracy of catheters and guidewires. Furthermore, existing devices generally rely on proximal force feedback technology, such as indirectly calculating the force on the instrument through drive motor current or strain gauges in the gripper. These measurements are affected by factors such as friction loss between the catheter / guidewire and the vessel wall, and deformation due to path bending, failing to accurately reflect the true contact force between the distal end of the instrument and the lesion tissue. This increases the risk of complications such as intraoperative vascular perforation and dissection. Summary of the Invention

[0005] The purpose of this invention is to provide a master-slave type interventional surgical robot force feedback system and method to solve the problem mentioned in the background art that the interventional surgical robot device in the prior art is difficult to maintain the coordinated motion accuracy of the catheter and guidewire, and cannot accurately reflect the real contact force between the distal end of the instrument and the lesion tissue.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a master-slave type interventional surgical robot force feedback system, comprising: a Y-valve rotation mechanism, a guidewire manipulation mechanism, and a balloon catheter manipulation mechanism disposed inside a housing; the guidewire manipulation mechanism is used to deliver or circumferentially rotate the guidewire; the balloon catheter manipulation mechanism is used to deliver the balloon catheter; the Y-valve rotation mechanism is connected to the end of an interventional force sensing catheter, the interventional force sensing catheter integrates an optical fiber force sensing module and has a bent front end; the Y-valve rotation mechanism is used to limit and retract the movement direction of the guidewire and balloon catheter into the interventional force sensing catheter, and to adjust the circumferential rotation direction of the interventional force sensing catheter so that when the interventional force sensing catheter is delivered into the blood vessel, it collects the three-dimensional contact force generated by the contact between the catheter tip and the blood vessel wall, and adjusts the orientation of the bent section of the interventional force sensing catheter tip to conform to the blood vessel wall.

[0007] Optionally, the fiber optic force sensing module is integrated at the end of the bending section at the front end of the interventional force sensing catheter; the fiber optic force sensing module includes a cylindrical elastomer and four through holes evenly distributed along its circumference, four fiber optic gratings are respectively fixed inside the through holes, and the sensing section of the fiber optic grating is suspended in the through holes; the elastomer has a through hole through which a guidewire or balloon catheter passes axially.

[0008] Optionally, it may also include: a catheter support mechanism, fixedly connected to the outer front end of the housing, for supporting the interventional force-sensing catheter; and a screw-type linear module, which is slidably engaged with the housing and the catheter support mechanism respectively, for driving the housing to slide back and forth and driving the catheter support mechanism to extend and retract back and forth, so as to deliver or withdraw the interventional force-sensing catheter.

[0009] Optionally, the catheter support mechanism includes several movably sleeved hollow tubes and support frames that are fixedly connected to each hollow tube. The support frames are slidably engaged with the screw-type linear module. The screw-type linear module drives the axially arranged screw to rotate, causing the outer shell threadedly connected to the screw to slide along the linear track in the screw-type linear module, thereby causing the catheter support mechanism to extend and retract back and forth.

[0010] Optionally, the Y-valve rotation mechanism includes: a Y-valve with a Y-shaped channel running through it, the Y-valve being connected to the interventional force-sensing catheter, the Y-valve being used to limit and retract the movement direction of the guidewire and balloon catheter into the interventional force-sensing catheter; and a rotation mechanism rotatably connected to the outer shell, the rotation mechanism being fixedly connected to the outside of the Y-valve, and by driving the rotation mechanism to rotate, the circumferential rotation direction of the Y-valve and the interventional force-sensing catheter can be adjusted.

[0011] Optionally, the guidewire manipulation mechanism includes a guidewire clamping and delivery mechanism and a rotary mechanism. The guidewire clamping and delivery mechanism and the rotary mechanism are coaxially connected inside the housing via two rotating shafts with V-grooves along the guidewire delivery path. The guidewire clamping and delivery mechanism includes: a delivery mechanism housing; a first driving wheel and a first driven wheel, horizontally arranged inside the delivery mechanism housing, which cooperate to deliver the guidewire; and a horizontally arranged ball screw, installed inside the delivery mechanism housing and connected to the first driven wheel via a bracket, for driving the guidewire... When the ball screw rotates, it converts the rotational motion into horizontal linear motion to adjust the distance between the first driving wheel and the first driven wheel, thereby adjusting the guide wire clamping force. The rotary mechanism includes: a slotted bevel gear, which is fixedly connected to the housing of the delivery mechanism. The slot of the slotted bevel gear is connected to and flush with the clamping positions of the first driving wheel and the first driven wheel; and a bevel gear, which is perpendicular to the rotation direction of the slotted bevel gear. The bevel gear meshes with the slotted bevel gear, and by driving the bevel gear to rotate, the guide wire clamping and delivery mechanism rotates as a whole, thereby driving the guide wire to rotate circumferentially.

[0012] Optionally, the balloon catheter operating mechanism includes: a balloon catheter operating mechanism housing; a second driving wheel and a second driven wheel, located inside the balloon catheter operating mechanism housing and arranged at intervals, delivering the balloon catheter through the cooperation of the second driving wheel and the second driven wheel; a driven wheel bracket, fixed inside the balloon catheter operating mechanism housing, and having a horizontal groove; the second driven wheel is fixedly connected to a slider and embedded in the groove of the driven wheel bracket, the slider having a horizontally arranged rack, which meshes with a gear fixedly connected to the motor output end, thereby driving the second driven wheel on the slider to slide along the horizontal groove closer to the second driving wheel, so as to realize the adjustment of the guidewire clamping force.

[0013] On the other hand, the present invention also provides a force feedback method for a master-slave operated interventional surgical robot based on the above-mentioned master-slave operated interventional surgical robot force feedback system. The method includes the following steps: establishing a mapping relationship between the three-dimensional force on the cylindrical elastic body and the strain of the fiber optic grating; merging the strain response under the three-dimensional force to establish a nonlinear mapping relationship matrix between the four fiber optic gratings and the three-dimensional force; collecting wavelength drift data through an optical fiber demodulator and implementing graded protection in combination with a preset force feedback threshold.

[0014] Optionally, the graded protection steps specifically include: when the force feedback data is in the low force range, the feedback force of the operating master hand is consistent with the measured value of the fiber optic force sensing module; when the force feedback data is in the medium force range, an axial damping force is added to the feedback force of the operating master hand; when the force feedback data is in the high force range, an emergency shutdown protection is triggered.

[0015] Optionally, the step of establishing the mapping relationship between the three-dimensional force on the cylindrical elastic body and the strain of the fiber grating specifically includes: when the fiber force sensing module is subjected to axial force, constructing a parallel spring model that includes the axial stiffness of the fiber and the axial stiffness of the elastic body, calculating the equivalent stiffness, calculating the uniform strain of the four fiber gratings according to Hooke's law, and establishing the correspondence between the axial force and the fiber wavelength drift; when the fiber force sensing module is subjected to radial force, determining the fiber strain distribution law according to Saint-Venant's translation theorem.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] This application utilizes a guidewire manipulation mechanism and a balloon catheter manipulation mechanism to operate the guidewire and balloon catheter separately. A Y-valve rotation mechanism limits and retracts the movement of the guidewire and balloon catheter into the interventional force-sensing catheter, achieving coordinated delivery of the guidewire and balloon catheter. The interventional force-sensing catheter integrates a fiber optic force-sensing module with a bent tip. The circumferential rotation direction of the interventional force-sensing catheter is adjusted by rotating the Y-valve rotation mechanism, allowing the catheter to collect the three-dimensional contact force generated when its tip contacts the vessel wall upon delivery into the blood vessel. The bending section of the interventional force-sensing catheter's tip is adjusted to conform to the vessel wall. This application allows physicians to operate without continuous exposure to X-ray radiation, significantly improving safety.

[0018] This application provides an interventional force-sensing catheter that integrates a fiber optic grating-based three-dimensional force sensing module onto the catheter, enabling the detection of three-dimensional force at the distal end of the catheter. Compared to the proximal force feedback of existing technologies, distal force feedback directly measures the contact force between the catheter tip and the blood vessel wall, which can more accurately reflect the actual interaction force between surgical instruments and human tissue, thereby helping doctors to better control the force and avoid excessive damage to blood vessels. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the force feedback system of the master-slave operation interventional surgical robot of the present invention.

[0020] Figure 2 This is a schematic diagram of the rotating mechanism in the Y-valve rotating mechanism of the present invention.

[0021] Figure 3 This is a schematic diagram of the catheter support mechanism of the present invention.

[0022] Figure 4 This is a schematic diagram of the guidewire manipulation mechanism and balloon catheter manipulation mechanism of the present invention.

[0023] Figure 5 This is a schematic diagram of the guide wire clamping and delivery mechanism of the present invention.

[0024] Figure 6 This is a schematic diagram of the balloon catheter operation mechanism of the present invention.

[0025] Figure 7 This is a schematic diagram of the fiber optic force sensing module structure of the present invention.

[0026] Figure 8 This is a schematic diagram of the force applied to the fiber optic force sensing module of the present invention.

[0027] Figure 9 This is a flowchart illustrating the force feedback method of the master-slave interventional surgical robot of the present invention.

[0028] In the figure: 1-Interventional force-sensing catheter, 11-Bending section, 12-Cylindrical elastomer, 13-Fiber grating, 2-Screw-type linear module, 3-Catheter support mechanism, 31-First hollow tube, 32-Second hollow tube, 33-Third hollow tube, 34-First support frame, 35-Second support frame, 36-Third support frame, 37-Locking component, 4-Outer shell, 5-Y valve rotation mechanism, 51-Rotating outer shell, 52-Drive shaft, 53-Drive gear, 54-Driven gear, 6-Guidewire manipulation mechanism, 61-Guidewire clamping and delivery mechanism, 611-First driving wheel, 612-First driven wheel, 613-Ball screw, 62-Slotted bevel gear, 63-Bevel gear, 7-Balloon catheter operation mechanism, 71-Second driving wheel, 72-Second driven wheel, 73-Slider, 74-Driven wheel bracket, 8-Balloon catheter, 9-Guidewire. Detailed Implementation

[0029] The present invention will now be clearly and completely described in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be used interchangeably where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0031] Those skilled in the art will understand that, unless explicitly stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in the specification of this application means the presence of features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein can include wireless connections or wireless coupling. The term “and / or” as used herein includes all or any units and all combinations of one or more associated listed items.

[0032] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0033] It should be understood that the sequence number and size of each step in this embodiment do not imply the order of execution. The execution order of each process is determined by its function and internal logic, and should not constitute any limitation on the implementation process of this application embodiment.

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] Please refer to Figures 1-8 The present invention discloses a master-slave type interventional surgical robot force feedback system, comprising: a Y-valve rotation mechanism 5, a guidewire manipulation mechanism 6, and a balloon catheter manipulation mechanism 7 disposed inside a housing 4; the guidewire manipulation mechanism 6 is used to deliver or circumferentially rotate a guidewire 9; the balloon catheter manipulation mechanism is used to deliver a balloon catheter 8; the Y-valve rotation mechanism 5 is connected to the end of the interventional force sensing catheter 1, the interventional force sensing catheter 1 integrates an optical fiber force sensing module and has a bent front end, the Y-valve rotation mechanism 5 is used to limit and retract the movement direction of the guidewire 9 and the balloon catheter 8 into the interventional force sensing catheter 1, and to adjust the circumferential rotation direction of the interventional force sensing catheter 1 so that when the interventional force sensing catheter 1 is delivered into the blood vessel, it collects the three-dimensional contact force generated by the contact between the catheter tip and the blood vessel wall, and adjusts the orientation of the bent section 11 at the front end of the interventional force sensing catheter 1 to conform to the blood vessel wall.

[0036] Specifically, this application uses a guidewire manipulation mechanism 6 and a balloon catheter manipulation mechanism 7 to operate the guidewire 9 and balloon catheter 8 respectively. A Y-valve rotation mechanism 5 limits and retracts the movement direction of the guidewire 9 and balloon catheter 8 into the interventional force-sensing catheter 1, achieving coordinated delivery of the guidewire 9 and balloon catheter 8. An optical fiber force-sensing module is integrated inside the interventional force-sensing catheter 1, with a bent front end. The circumferential rotation direction of the interventional force-sensing catheter 1 is adjusted by rotating the Y-valve rotation mechanism 5, so that when the interventional force-sensing catheter 1 is delivered into the blood vessel, it collects the three-dimensional contact force generated by the catheter tip contacting the blood vessel wall. The orientation of the bent section 11 at the front end of the interventional force-sensing catheter 1 is adjusted to conform to the blood vessel wall. This application allows doctors to operate without continuous exposure to X-ray radiation, greatly improving safety. This application provides an interventional force-sensing catheter 1, which integrates a three-dimensional force-sensing module based on a fiber optic grating 13 onto the catheter, realizing the detection of three-dimensional force at the distal end of the catheter. Compared with the proximal force feedback of the prior art, the distal force feedback directly measures the contact force between the catheter tip and the blood vessel wall, which can more accurately reflect the actual interaction force between the surgical instrument and human tissue, thereby helping doctors to better control the force and avoid excessive damage to blood vessels.

[0037] In some embodiments, the fiber optic force sensing module is integrated at the end of the bending section 11 at the front end of the interventional force sensing catheter 1; the fiber optic force sensing module includes a cylindrical elastomer 12 and four through holes evenly distributed along its circumference, four fiber optic gratings 13 are respectively fixed inside the through holes, and the sensing section of the fiber optic grating 13 is suspended in the through holes; the elastomer has a through hole through which the guidewire 9 or balloon catheter 8 passes axially.

[0038] Specifically, by combining the cylindrical elastomer 12 with four fiber optic gratings 13, three-dimensional real-time accurate measurement of the contact force between the distal end of the catheter and the blood vessel wall is achieved. The sensing segment of the fiber optic grating 13 is suspended in the through hole, which significantly improves the resolution of the force signal. The use of fiber optic sensors eliminates electromagnetic interference and is suitable for surgical scenarios in complex electromagnetic environments.

[0039] In some embodiments, the device further includes: a catheter support mechanism 3, fixedly connected to the outer front end of the housing 4, for supporting the interventional force sensing catheter 1; and a screw-type linear module 2, which is slidably engaged with the housing 4 and the catheter support mechanism 3 respectively, for driving the housing 4 to slide back and forth and driving the catheter support mechanism 3 to extend and retract back and forth, so as to deliver or withdraw the interventional force sensing catheter 1.

[0040] Specifically, the three-level nested telescopic hollow tube uses adaptive telescopic extension to offset the axial thrust during catheter delivery, preventing bending deformation of the distal end of the catheter. The support frame is linked with the screw-type linear module 2 to compensate for changes in the catheter delivery length in real time and maintain support stability.

[0041] In some embodiments, the catheter support mechanism 3 includes a plurality of movably sleeved hollow tubes and a support frame fixedly connected to each hollow tube. The support frame is slidably engaged with the screw-type linear module 2. The screw-type linear module 2 rotates toward a screw via a drive shaft 52, causing the outer shell threadedly connected to the screw to slide along a linear track in the screw-type linear module 2, thereby causing the catheter support mechanism 3 to extend and retract back and forth.

[0042] Specifically, the catheter support mechanism 3 provides support for the interventional force-sensing catheter 1. The bottom of the outer shell has a slider that is slidably disposed inside the screw-type linear module 2, and the slider is threadedly connected to the screw in the screw-type linear module 2. When the screw is rotated, the outer shell can be driven to slide along the linear track in the screw-type linear module 2, thereby driving the catheter support mechanism 3 to extend and retract back and forth, so that doctors do not need to be exposed to X-ray radiation during operation, which greatly improves safety.

[0043] In some embodiments, the Y-valve rotation mechanism 5 includes: a Y-valve with a Y-shaped channel running through it, the Y-valve being connected to the interventional force-sensing catheter 1, the Y-valve being used to limit and retract the movement direction of the guidewire 9 and the balloon catheter 8 into the interventional force-sensing catheter 1; and a rotation mechanism rotatably connected to the housing 4, the rotation mechanism being fixedly connected to the outside of the Y-valve, and by driving the rotation mechanism to rotate, the circumferential rotation direction of the Y-valve and the interventional force-sensing catheter 1 can be adjusted.

[0044] Specifically, the through-slot design of the slotted spur gear set and the rotating housing 51 supports the rapid intraoperative replacement of instruments such as guidewire 9 and balloon catheter 8. The gear set, namely the drive gear 53 and the driven gear 54, is driven by a DC motor to achieve ±180° rotation of the Y valve and the catheter tip, meeting the vascular branch turning requirements.

[0045] In some embodiments, the guide wire manipulation mechanism 6 includes a guide wire clamping and delivery mechanism 61 and a rotary mechanism. The guide wire clamping and delivery mechanism 61 and the rotary mechanism are coaxially connected to the inside of the housing 4 via two rotating shafts with V-grooves along the guide wire 9 delivery path. The guide wire clamping and delivery mechanism 61 includes: a delivery mechanism housing; a first driving wheel 611 and a first driven wheel 612, horizontally arranged inside the delivery mechanism housing, which deliver the guide wire 9 through the cooperation of the first driving wheel 611 and the first driven wheel 612; and a horizontally arranged ball screw 613, installed inside the delivery mechanism housing and connected to the first driven wheel 612 via a bracket, which drives the guide wire 9. When the ball screw 613 rotates, it converts the rotational motion into horizontal linear motion to adjust the distance between the first driving wheel 611 and the first driven wheel 612, thereby adjusting the clamping force of the guide wire 9. The rotary mechanism includes: a slotted bevel gear 62, which is fixedly connected to the housing of the delivery mechanism. The slot of the slotted bevel gear 62 is connected to and flush with the clamping positions of the first driving wheel 611 and the first driven wheel 612; and a bevel gear 63, which is perpendicular to the rotation direction of the slotted bevel gear 62. The bevel gear 63 meshes with the slotted bevel gear 62. By driving the bevel gear 63 to rotate, the guide wire clamping and delivery mechanism 61 rotates as a whole, thereby driving the guide wire 9 to rotate circumferentially.

[0046] In some embodiments, the balloon catheter operating mechanism includes: a balloon catheter operating mechanism housing; a second driving wheel 71 and a second driven wheel 72, located inside the balloon catheter operating mechanism housing and arranged at intervals, delivering the balloon catheter 8 through the cooperation of the second driving wheel 71 and the second driven wheel 72; a driven wheel bracket 74, fixed inside the balloon catheter operating mechanism housing, and having a horizontal groove; the second driven wheel 72 is fixedly connected to a slider 73 and embedded in the groove of the driven wheel bracket 74, the slider 73 has a horizontally arranged rack, which meshes with a gear fixedly connected to the output end of a motor, thereby driving the second driven wheel 72 on the slider 73 to slide along the horizontal groove closer to the second driving wheel 71, so as to adjust the clamping force of the guidewire 9.

[0047] Please refer to Figure 9 On the other hand, the present invention also provides a master-slave operation interventional surgical robot force feedback method based on the above-mentioned master-slave operation interventional surgical robot force feedback system. The method includes the following steps: establishing a mapping relationship between the three-dimensional force on the cylindrical elastic body 12 and the strain of the fiber optic grating 13; merging the strain response under the three-dimensional force to establish a nonlinear mapping relationship matrix between the four fiber optic gratings 13 and the three-dimensional force; collecting wavelength drift data through an optical fiber demodulator and implementing graded protection in combination with a preset force feedback threshold.

[0048] In some embodiments, the step of establishing the mapping relationship between the three-dimensional force on the cylindrical elastic body 12 and the strain of the fiber optic grating 13 specifically includes: when the fiber optic force sensing module is subjected to an axial force, constructing a parallel spring model that includes the axial stiffness of the fiber and the axial stiffness of the elastic body, calculating the equivalent stiffness, calculating the uniform strain of the four fiber optic gratings 13 according to Hooke's law, and establishing the correspondence between the axial force and the fiber wavelength drift; when the fiber optic force sensing module is subjected to a radial force, determining the fiber strain distribution law according to Saint-Venant's translation theorem.

[0049] Specifically, based on the sensing principle of fiber Bragg grating 13, the strain sensitivity characteristic can be quantified as follows: In the formula, This represents the Bragg center wavelength shift. This is the wavelength shift. The elastic-optical coefficient of the silica optical fiber is denoted as . As the axial strain increment, analyze the relationship between the three-dimensional force and the strain of fiber grating 13 when the fiber grating sensing module is subjected to anisotropic three-dimensional forces:

[0050] When the cylindrical elastic body 12 is subjected to an axial force Fz, both the cylindrical elastic body 12 and the four fiber gratings 13 will undergo compressive deformation. According to the theory of axial compression deformation in mechanics of materials, the fiber grating force sensing module can be equivalent to a compressed spring system. However, since the fiber grating sensing module includes the cylindrical elastic body 12 and the four fiber gratings 13, the axial stiffness of both the fiber gratings 13 and the elastic body needs to be considered simultaneously. The axial stiffness of the optical fiber is calculated based on the knowledge of mechanics of materials: In the formula, For the axial stiffness of the optical fiber, The elastic modulus of optical fiber. The cross-sectional area of ​​the optical fiber. This refers to the length of the intermediate axis, i.e., the length of the fiber optic suspension section.

[0051] Calculate the axial stiffness of the elastic body: In the formula, This refers to the axial stiffness of the elastic body. The elastic modulus of the elastomer. The cross-sectional area of ​​the elastic body of the fiber suspension section. This refers to the length of the intermediate axis, i.e., the length of the fiber optic suspension section.

[0052] The four optical fibers and the elastic body are subjected to the same strain, so they are assumed to be a parallel spring system, and the equivalent stiffness of the parallel springs is calculated: In the formula, For equivalent stiffness, For the axial stiffness of the optical fiber, This represents the axial stiffness of the elastic body.

[0053] The strain produced by the four optical fibers is the same. According to Hooke's law, the uniform strain produced by the axial force on the optical fiber can be calculated: In the formula, To achieve uniform strain in the four fiber gratings 13 under axial force. It is an axial force. For the sensor's equivalent stiffness, This refers to the length of the intermediate axis, i.e., the length of the fiber optic suspension section.

[0054] From the above, we can obtain the mapping relationship between the center wavelength drift of the four fiber gratings 13 and the axial force: In the formula, , , , This represents the center wavelength shift of the four fiber Bragg gratings. This is the wavelength shift. The elastic-optical coefficient of the silica optical fiber is denoted as . The elastic modulus of optical fiber. The cross-sectional area of ​​the optical fiber. The elastic modulus of the elastomer. The cross-sectional area of ​​the elastic body of the fiber suspension section. This is the axial force.

[0055] When the sensor is subjected to a radial force Fy along the y-direction, due to the sensor's symmetrical structure, the first and third optical fibers are stretched and compressed respectively, experiencing strains of the same magnitude but opposite directions. The second and fourth optical fibers, located in the sensor's neutral layer, theoretically experience zero strain. According to Saint-Venant's translation theorem, translating Fy from the distal step surface of the elastic body to the interface with the intermediate axis is equivalent to a radial shear force Fy and a bending moment My about the neutral axis, My = FyL2 (L2 is the lever arm length, i.e., the length of the distal step). The forces acting on the sensor are as follows... Figure 8 As shown, the uniform strain produced by the force in the y-direction on the four optical fibers can be calculated using the unit load method in mechanics of materials: In the formula, This represents the uniform strain generated by the four fiber gratings 13 when subjected to a force in the y-direction. The radial force is in the y-direction. The moment of inertia of a single optical fiber, This refers to the moment of inertia of the elastic body of the fiber suspension section, i.e., the moment of inertia along the intermediate axis. This refers to the length of the intermediate axis, i.e., the length of the fiber optic suspension section. It is twice the distance from the fiber optic aperture to the central axis.

[0056] Calculate the moment of inertia of a single optical fiber: In the formula, The moment of inertia of a single optical fiber, The radius of fiber grating 13 is... It is twice the distance from the fiber optic aperture to the central axis.

[0057] Calculate the moment of inertia of the intermediate axis: In the formula, The moment of inertia of the elastic body of the fiber suspension section. The diameter of the intermediate shaft segment of the elastomer. It is twice the distance from the fiber optic aperture to the central axis. The diameter of the fiber optic aperture. The diameter of the central hole of the elastomer.

[0058] The mapping relationship between the center wavelength drift of the four fiber gratings 13 and the radial force Fy is as follows: In the formula, , , , This represents the center wavelength shift of the four fiber Bragg gratings. This is the wavelength shift. The elastic-optical coefficient of the silica optical fiber is denoted as . The elastic modulus of optical fiber. The moment of inertia of a single optical fiber, The elastic modulus of the elastomer. The moment of inertia of the elastic body of the fiber suspension section. , The length of the intermediate axis. Let d be the radial force in the y-direction, and dz be the integral over an infinitesimal increment of the z-coordinate.

[0059] When subjected to radial force in the x direction At this time, the second and fourth optical fibers are subjected to tensile and compressive forces, respectively, resulting in strains of the same magnitude but opposite directions. The first and third optical fibers, located in the neutral layer of the sensor, theoretically experience zero strain. Similarly, the axial uniform strain occurring in all four optical fibers can be obtained:

[0060] In the formula, To represent the uniform strain generated in the four optical fibers when subjected to a force in the x-direction. The radial force is in the x-direction. It is twice the distance from the fiber optic aperture to the central axis. The elastic modulus of optical fiber. The moment of inertia of a single optical fiber, The elastic modulus of the elastomer. The moment of inertia of the elastic body of the fiber suspension section. , Let d be the length of the intermediate axis, and dz be the integral over the infinitesimal increment of the z-coordinate.

[0061] The center wavelength drift and radial force of four fiber optic gratings 13 The mapping relationship is as follows: In the formula, , , , This represents the center wavelength shift of the four fiber Bragg gratings. This is the wavelength shift. The elastic-optical coefficient of the silica optical fiber is denoted as . The elastic modulus of optical fiber. The moment of inertia of a single optical fiber, The elastic modulus of the elastomer. The moment of inertia of the elastic body of the fiber suspension section. The radial force is in the y-direction. , Let be the length of the intermediate axis, and dz be the integral over the infinitesimal increment of the z-coordinate. It is twice the distance from the fiber optic aperture to the central axis.

[0062] Based on the above matrix relating force to the center wavelength drift of the four FBGs when applied to the sensor in a single-dimensional force, a mapping model between the external three-dimensional force and the response of the sensor's four FBGs can be obtained: In the formula, , , , This represents the center wavelength shift of the four fiber Bragg gratings. This is the wavelength shift. The elastic-optical coefficient of the silica optical fiber is denoted as . The elastic modulus of optical fiber. The moment of inertia of a single optical fiber, The elastic modulus of the elastomer. The moment of inertia of the elastic body of the fiber suspension section. The radial force is in the x-direction. The radial force is in the y-direction. It is an axial force. The elastic modulus of optical fiber. The cross-sectional area of ​​the optical fiber. The elastic modulus of the elastomer. The cross-sectional area of ​​the elastic body of the fiber suspension section. , Let be the length of the intermediate axis, and dz be the integral over the infinitesimal increment of the z-coordinate. It is twice the distance from the fiber optic aperture to the central axis.

[0063] Assumption: We can obtain the linear mapping matrix between the external three-dimensional force and the response of the four FBGs of the sensor: In the formula, It is a linear mapping matrix. This is the wavelength shift. The elastic-optical coefficient of the silica optical fiber is denoted as . The elastic modulus of optical fiber. The moment of inertia of a single optical fiber, The elastic modulus of the elastomer. The moment of inertia of the elastic body of the fiber suspension section. The radial force is in the x-direction. The radial force is in the y-direction. It is an axial force. The elastic modulus of optical fiber. The cross-sectional area of ​​the optical fiber. The elastic modulus of the elastomer. The cross-sectional area of ​​the elastic body of the fiber suspension section. , Let be the length of the intermediate axis, and dz be the integral over the infinitesimal increment of the z-coordinate. It is twice the distance from the fiber optic aperture to the central axis.

[0064] In some embodiments, the graded protection steps specifically include: when the force feedback data is in the low force range, the feedback force of the operating master hand is consistent with the measured value of the fiber optic force sensing module; when the force feedback data is in the medium force range, an axial damping force is added to the feedback force of the operating master hand; when the force feedback data is in the high force range, an emergency shutdown protection is triggered.

[0065] Specifically, the doctor controls the main hand to complete three actions of surgical robot delivery, twisting, and clamping. The three-dimensional force fiber optic sensing module at the distal end of the catheter senses the interaction force between the catheter and the patient, converts the interaction force into an optical signal and transmits it to the fiber optic demodulator. The host computer stores the grating center wavelength data processed by the demodulator through serial communication. Based on the established wavelength drift and three-dimensional force mapping relationship, it solves the slave-end interaction force data and transmits it to the cloud platform through TCP / IP communication. The cloud platform sends the slave-end interaction force data to the host computer through TCP / IP communication. The host computer sends the master-end target force to the main hand controller through serial communication. The main hand provides tactile force feedback to the doctor.

[0066] To address the common problem of lack of force feedback in current VISR (Virtual Hand Recognition System), this paper proposes a hierarchical protection strategy based on preset force feedback thresholds, building upon the implementation of master-slave hand following and slave-end interactive force feedback in VISR. In the formula, The target force set by the main hand force feedback. The resultant force value is sensed by the fiber optic three-dimensional force sensor at the distal end of the catheter. This represents the axial distance increment for catheter delivery. This represents the increment of the catheter rotation angle. is impedance is the set first force threshold is the set second force threshold is the radial force in the x direction is the radial force in the y direction is the axial force

[0067] Set the force thresholds F1 and F2 (F1 < F2). When the combined force value sensed by the three-dimensional force fiber sensor at the distal end of the catheter is less than F1, set the target force of the master hand force feedback equal to the three-dimensional force of the sensor; when the combined force value of the sensor is greater than F1 and less than F2, an additional spring impedance force is applied along the axial direction of the sensor, i.e., the catheter delivery direction, to warn the doctor that there is a risk of blood vessel wall perforation in the current surgical action and it should be corrected in a timely manner; when the combined force value of the sensor is greater than F2, immediately stop the delivery and rotation of the catheter to prevent blood vessel wall perforation.

[0068] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of this technical solution can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods in various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0069] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, database or other media used in the embodiments provided by the present invention can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0070] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention's specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A master-slave type interventional surgical robot force feedback system, characterized in that, include: The Y-valve rotation mechanism, guidewire manipulation mechanism, and balloon catheter manipulation mechanism are all located inside the housing. The guidewire manipulation mechanism is used to deliver or rotate the guidewire circumferentially. The balloon catheter manipulation mechanism is used to deliver the balloon catheter; The Y-valve rotation mechanism is connected to the end of the interventional force sensing catheter. The interventional force sensing catheter integrates a fiber optic force sensing module and has a bent front end. The Y-valve rotation mechanism is used to limit and retract the movement direction of the guidewire and balloon catheter into the interventional force sensing catheter, and to adjust the circumferential rotation direction of the interventional force sensing catheter so that when the interventional force sensing catheter is delivered into the blood vessel, it can collect the three-dimensional contact force generated by the contact between the catheter tip and the blood vessel wall, and adjust the orientation of the bent section at the front end of the interventional force sensing catheter to conform to the blood vessel wall.

2. The master-slave operation interventional surgical robot force feedback system according to claim 1, characterized in that, The fiber optic force sensing module is integrated at the end of the bending section at the front end of the interventional force sensing catheter; the fiber optic force sensing module includes a cylindrical elastomer and four through holes evenly distributed along its circumference, four fiber optic gratings are respectively fixed inside the through holes, and the sensing section of the fiber optic grating is suspended in the through holes; the elastomer has a through hole through which a guidewire or balloon catheter passes axially.

3. The master-slave operation interventional surgical robot force feedback system according to claim 1, characterized in that, Also includes: A catheter support mechanism is fixedly connected to the outer front end of the housing and is used to support the interventional force sensing catheter. A screw-type linear module is slidably engaged with the housing and the catheter support mechanism, respectively, to drive the housing to slide back and forth and to drive the catheter support mechanism to extend and retract back and forth, so as to deliver or withdraw the interventional force-sensing catheter.

4. The master-slave operation interventional surgical robot force feedback system according to claim 3, characterized in that, The catheter support mechanism includes several movably sleeved hollow tubes and support frames that are fixedly connected to each hollow tube. The support frames are slidably engaged with the screw-type linear module. The screw-type linear module drives the axially arranged screw to rotate, causing the outer shell, which is threadedly connected to the screw, to slide along the linear track in the screw-type linear module, thereby causing the catheter support mechanism to extend and retract back and forth.

5. The master-slave operation interventional surgical robot force feedback system according to claim 1, characterized in that, The Y-valve rotation mechanism includes: The Y-valve has a Y-shaped channel running through it. The Y-valve is connected to the interventional force sensing catheter. The Y-valve is used to limit and retract the movement direction of the guidewire and balloon catheter into the interventional force sensing catheter. A rotating mechanism is rotatably connected to the housing and fixedly connected to the outside of the Y valve. By driving the rotating mechanism to rotate, the circumferential rotation direction of the Y valve and the interventional force sensing conduit can be adjusted.

6. The master-slave operation interventional surgical robot force feedback system according to claim 1, characterized in that, The guide wire manipulation mechanism includes a guide wire clamping and delivery mechanism and a rotary mechanism. The guide wire clamping and delivery mechanism and the rotary mechanism are coaxially connected inside the housing via two rotating shafts with V-grooves along the guide wire delivery path. The guidewire clamping and delivery mechanism includes: Delivery mechanism housing; The first driving wheel and the first driven wheel are horizontally arranged inside the housing of the delivery mechanism, and the guide wire is delivered through the cooperation of the first driving wheel and the first driven wheel; A horizontally positioned ball screw is installed inside the housing of the delivery mechanism and connected to the first driven wheel via a bracket. When the ball screw is driven to rotate, the rotational motion is converted into horizontal linear motion, thereby adjusting the distance between the first driving wheel and the first driven wheel to adjust the guide wire clamping force. The rotary mechanism includes: A slotted bevel gear is fixedly connected to the housing of the delivery mechanism, and the slot of the slotted bevel gear is connected to and flush with the clamping positions of the first driving wheel and the first driven wheel; The bevel gear is perpendicular to the rotation direction of the slotted bevel gear. The bevel gear meshes with the slotted bevel gear. By driving the bevel gear to rotate, the guide wire clamping and delivery mechanism rotates as a whole, thereby driving the guide wire to rotate circumferentially.

7. The master-slave operation interventional surgical robot force feedback system according to claim 1, characterized in that, The balloon catheter manipulation mechanism includes: balloon catheter manipulation mechanism housing; The second driving wheel and the second driven wheel are located inside the housing of the balloon catheter operating mechanism and are arranged at intervals. The balloon catheter is delivered through the cooperation of the second driving wheel and the second driven wheel. The driven wheel bracket is fixed inside the outer shell of the balloon catheter operating mechanism and has a horizontal sliding groove. The second driven wheel is fixedly connected to the slider and embedded in the groove of the driven wheel bracket. The slider has a horizontally arranged rack, which meshes with the rack through a gear fixedly connected to the motor output end, thereby driving the second driven wheel on the slider to slide along the horizontal groove and approach the second driving wheel, so as to realize the adjustment of the guide wire clamping force.

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