Gripping force determination method for a gripping instrument and surgical robot system

Abstract

The present disclosure discloses a method for determining a clamping force of a clamping instrument. The method comprises: determining a proximal displacement of a driving wire of the clamping instrument, the driving wire being used to drive the clamping instrument to open and close; determining a distal displacement of the driving wire; calculating an elastic force of the driving wire based on the proximal displacement and the distal displacement of the driving wire; and calculating the clamping force of the clamping instrument based on the elastic force of the driving wire.

Description

Technical Field

[0001] This disclosure relates to the fields of machinery and robotics, and in particular to a method for determining the clamping force of clamping instruments and a surgical robot system. Background Technology

[0002] Minimally invasive surgery has become a widely used surgical procedure in recent years, characterized by less surgical trauma and shorter patient recovery time. The advent of surgical robots has further enhanced the precision and stability of minimally invasive surgery.

[0003] During robotic surgery, surgical instruments are remotely controlled to operate on the surgical site. During this process, the instruments come into direct contact with the tissue. For example, clamping instruments may grip the tissue. The operator (e.g., the surgeon) may need to be aware of the clamping forces exerted on the tissue by these instruments during the procedure.

[0004] Typically, clamping force can be detected by adding sensors, such as pressure sensors. This increases the structural complexity of the surgical instruments, their size and weight, as well as the difficulty of controlling them and the likelihood of malfunction. Summary of the Invention

[0005] Some embodiments of this disclosure provide a method for determining the clamping force of a clamping device, comprising: determining a proximal displacement of a drive wire of the clamping device, the drive wire being used to drive the clamping device to open and close; determining a distal displacement of the drive wire; calculating an elastic force of the drive wire based on the proximal and distal displacements of the drive wire; and calculating the clamping force of the clamping device based on the elastic force of the drive wire.

[0006] Some embodiments of this disclosure provide a computer-readable medium having instructions stored thereon that, when executed by a processor, cause a computer to perform a method according to some embodiments of this disclosure.

[0007] Some embodiments of this disclosure provide a surgical robot system, including: at least one carriage; at least one positioning arm connected to the at least one carriage; at least one surgical instrument detachably connected to the distal end of the at least one positioning arm, the at least one surgical instrument including a clamping device, the clamping device including a clamp and a drive wire for driving the clamp to open and close; and a processor for performing a method according to some embodiments of this disclosure. Attached Figure Description

[0008] Figure 1 A schematic diagram of a clamping device according to some embodiments of the present disclosure is shown.

[0009] Figure 2 A cross-sectional schematic diagram of a clamping device according to some embodiments of the present disclosure is shown.

[0010] Figure 3 A flowchart illustrating a method for determining the clamping force of a clamping device according to some embodiments of the present disclosure is shown.

[0011] Figure 4 A perspective view of a clamp according to some embodiments of the present disclosure is shown.

[0012] Figure 5 A cross-sectional schematic diagram of the pliers head according to some embodiments of the present disclosure is shown.

[0013] Figure 6 A partial cross-sectional view of a clamp according to some embodiments of the present disclosure is shown.

[0014] Figure 7 A schematic diagram of a surgical robot system according to some embodiments of the present disclosure is shown. Detailed Implementation

[0015] The embodiments of this disclosure will be described in detail below with reference to the accompanying drawings to provide a clearer understanding of the purpose, features, and advantages of this disclosure. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of this disclosure, but are merely illustrative of the essential spirit of the technical solutions disclosed.

[0016] In the description of this disclosure, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this disclosure and for simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "connected," "coupled," and "coupled" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure based on the specific circumstances.

[0017] In this disclosure, the end closer to the operator (e.g., a doctor) is defined as the proximal end, proximal or posterior end, or posterior part, and the end closer to the surgical patient is defined as the distal end, distal or anterior end, or anterior part. Those skilled in the art will understand that the growable device according to embodiments of this disclosure can be used in the medical field as well as in other non-medical fields.

[0018] Figure 1A schematic diagram of a clamping device 100 according to some embodiments of the present disclosure is shown. For example... Figure 1 As shown, the clamping device 100 may include: a drive / transmission unit 1, an arm 2, and a clamp 3. The drive / transmission unit 1 may include a housing and a drive or transmission device housed within the housing. In some embodiments, the drive device may include one or more motors. In some embodiments, such as Figure 1 As shown, the transmission device may include one or more couplings 6 for coupling with and receiving power from the drive motor.

[0019] like Figure 1 As shown, the arm body 2 includes a proximal end 21 and a distal end 22. The proximal end 21 of the arm body 2 is connected to the drive / transmission unit 1, and the distal end 22 of the arm body 2 is connected to the clamp 3. In some embodiments, the clamp 3 may be fixedly connected to the distal end 22 of the arm body 2, or it may be movably connected to the distal end 22 of the arm body 2 via a wrist joint rotatable in one or more degrees of freedom. In some embodiments, the arm body 2 may be a flexible arm body, for example, including a continuous structure. The flexible arm body may be driven by the drive / transmission unit 1 to move in one or more degrees of freedom. For example, the drive / transmission unit 1 includes a linear transmission device (not shown) for converting rotational motion into linear motion. The linear transmission device converts the rotational motion received by the coupling 6 into linear motion to push or pull the drive wire of the arm body 2, thereby driving the arm body 2 to move and enabling the clamp 3 to achieve a specific pose. In some embodiments, the arm body 2 may be a rigid rod. The clamping device 100 may include a wrist joint movably connected to the distal end 22 of the arm body 2, such that the clamp 3 can rotate in one or more degrees of freedom.

[0020] Figure 2 A cross-sectional schematic diagram of a clamping device 100 according to some embodiments of the present disclosure is shown. For example... Figure 2 As shown, the clamping device 100 includes a drive wire 4 for driving the clamp 3. The drive wire 4 is disposed inside the arm body 2 along the length direction of the arm body 2. The distal end of the drive wire 4 is connected to the clamp 3 for driving the opening and closing of the clamp 3. The proximal end of the drive wire 4 is connected to the drive / transmission unit 1. In some embodiments, the proximal end of the drive wire 4 is connected to a linear transmission device. The linear transmission device converts the rotational motion received by the coupling 6 into linear motion to push or pull the drive wire 4 in order to control the opening and closing of the clamp 3. For example, the linear transmission device pulls the drive wire 4 proximally, thereby driving the clamp 3 to decrease its opening angle. Conversely, the linear transmission device pushes the drive wire 4 distally, thereby driving the clamp 3 to increase its opening angle.

[0021] In some embodiments, the drive wire 4 is a deformable drive wire. The drive wire 4 has axial rigidity and can be subjected to axial pressure or tension and generate a reaction thrust or elastic force. The drive wire 4 may include an elastic material, such as a nickel-titanium alloy.

[0022] In some embodiments, the drive wire 4 can move axially proximally, pulling the clamp 3 so that the clamp 3's opening angle decreases, gradually approaching the target object. After the clamp 3 contacts the target object, the drive wire 4 can continue to move axially. If the target object is soft human tissue, the clamp 3's opening angle continues to decrease, and the drive wire 4 deforms (e.g., axially elongates), thereby applying a clamping force to the target object through the clamp 3. If the target object is a rigid object (e.g., surgical instruments, implants, etc.), the clamp 3's opening angle no longer decreases, the drive wire 4 deforms, and the clamp 3 applies a clamping force to the target object.

[0023] The clamping force Fg of clamp 3 at time t t The following formula can be used for calculation:

[0024] Fg t =k g ·F t (1)

[0025] Among them, F t k is the elastic force generated by the deformation of the driving wire 4 at time t. g Let F be the transmission coefficient of clamp 3. The elastic force F of drive wire 4 at time t. t The following formula can be used for calculation:

[0026]

[0027] ΔL t =L t -L0 (3)

[0028] Where E is the elastic modulus of the driving wire 4, S is the cross-sectional area of ​​the driving wire 4, and ΔL t Let L be the deformation of driving wire 4 at time t, and L0 be the initial length of driving wire 4. t L is the length of the driving wire 4 at time t. In some embodiments, L t This can be obtained by detecting the deformation of the drive wire 4. Since the target object held by the clamp 3 may be soft human tissue, the deformation of the drive wire 4 can be determined by detecting the proximal and distal displacements of the drive wire 4.

[0029] Figure 3 This illustration shows methods for determining clamping devices (e.g., according to some embodiments of the present disclosure). Figure 1-2 The flowchart illustrates a method 300 for applying clamping force to a gripping device 100 or clamp 3. Method 300 can be implemented or executed by hardware, software, or firmware. In some embodiments, method 300 can be implemented by a robot system (e.g., Figure 7The surgical robot system 700 executes the method. In some embodiments, method 300 can be implemented as computer-readable instructions. These instructions can be read and executed by a general-purpose processor or a special-purpose processor. In some embodiments, these instructions can be stored on a computer-readable medium.

[0030] like Figure 3 As shown, in step 301, the proximal displacement D of the drive wire of the clamping device can be determined. p In some embodiments, the drive motor of the gripper is configured with a stroke sensor to detect the motor's stroke. Method 300 may include (e.g., receiving the stroke M of the drive motor of the gripper from the stroke sensor) and calculating the proximal displacement D of the drive wire based on the stroke M. p The initial stroke of the drive motor (e.g., the stroke of the drive motor in its natural state with no load on the clamping device) can be set as M0, and at time t, the stroke of the drive motor is M. t The stroke variable of the drive motor can be calculated using the following formula:

[0031] ΔM=M t -M0 (4)

[0032] Due to the presence of mechanical transmission mechanisms (such as linear transmission devices), the motor stroke variable ΔM is related to the near-end displacement D. p There may be a transmission coefficient k between them. m Therefore, the proximal displacement D p The following formula can be used for calculation:

[0033] D p =k m ΔM (5)

[0034] In some embodiments, the drive / transmission unit 1 (e.g., a linear transmission device) may be equipped with a proximal displacement sensor for detecting the proximal displacement D of the drive wire. p For example, a linear transmission device may include a screw and a slider rotatably connected to the screw. The screw may be connected to a coupling 6 to rotate under the drive of the coupling 6. The rotation of the screw may drive the slider to slide linearly along the screw. A drive wire 4 is fixedly connected to the slider to move under the drive of the slider's linear sliding. In some embodiments, the proximal displacement sensor may be a stroke sensor coupled to the screw. Similar to the stroke sensor of the drive motor described above, the stroke sensor coupled to the screw can detect the stroke of the screw. Based on the detected screw travel, the proximal displacement D can be calculated using the transmission coefficient. pIn some embodiments, the proximal displacement sensor may be a Hall sensor disposed in the drive / transmission unit 1. The slider may include a magnetic material and, during linear sliding along the screw, cuts the magnetic field of the Hall sensor. The Hall sensor can detect the stroke of the slider to obtain the proximal displacement D of the drive wire 4. p .

[0035] In step 303, the distal displacement D of the drive wire of the clamping device can be determined. d In some embodiments, during the operation of the clamping instrument, a vision module (e.g., an endoscope used during surgical procedures) captures images of the operation of the clamping instrument. Method 300 may include analyzing images of the clamping instrument (e.g., forceps head 3) and determining the distal displacement D of the drive wire. d For example, such as Figure 2 As shown, the two jaws of clamp 3 are hinged together, and the drive wire 4 can be hinged or fixedly connected to the hinge point of the two jaws of clamp 3. Method 300 may include analyzing an image of clamp 3 to identify the displacement of the hinge point, thereby obtaining the distal displacement D of the drive wire. d .

[0036] In some embodiments, the clamping device 100 may include a distal displacement sensor disposed on the clamp 3. For example, the distal displacement sensor may be a Hall sensor disposed on the clamp 3. Figure 2 As shown, the connection points between the two jaws of the clamp 3 and the drive wire 4 may include magnetic material. During the movement of the drive wire 4, the magnetic material cuts the magnetic field of the Hall sensor. The Hall sensor can detect the travel of the connection points, thereby obtaining the distal displacement D of the drive wire 4. d Method 300 may include receiving a displacement value detected by a distal displacement sensor disposed on the clamp, and determining the distal displacement of the drive wire based on the detected displacement value.

[0037] Displacement D at the distal end of drive wire 4 d The detection is related to the structure of clamp 3. As an example, Figure 4 A perspective schematic diagram of another structure of the clamp 3 according to some embodiments of the present disclosure is shown. For example... Figure 4 As shown, the clamp 3 includes mating jaws 31 and 32. Jaws 31 and 32 are connected at a pivot point 33 by a pivot pin (not shown). The body of jaw 31 has a pair of grooves 35 on opposite sides, while the body of jaw 32 has a pair of grooves 36 on opposite sides that mate with the grooves 35 of jaw 31. A sliding pin 34 passes through the grooves 35 and 36 and is fixedly connected to a drive wire 4. The drive wire 4 can drive the sliding pin 34 to slide within the grooves 35 and 36 to control the opening and closing of the clamp 3.

[0038] Figure 5 A schematic cross-sectional view of the pliers head 32 according to some embodiments of the present disclosure is shown. Figure 5 As shown, the axis of the groove 36 of the jaw 32 forms an angle α with the extended plane of the clamping contact surface of the jaw 32. The axis of the groove 35 of the jaw 31 can be parallel to the extended plane of the clamping contact surface of the jaw 31. Therefore, when the sliding pin 34 slides in the grooves 35 and 36, different clamping angles of the jaws 3 can be achieved. The total variable stroke of the sliding pin 34 in the groove 36 is L. 20 The total variable stroke of sliding pin 34 within slide groove 35 is L. 10 At time t, the stroke of sliding pin 34 in slide groove 35 is denoted as D. 1t The stroke of sliding pin 34 in slide groove 36 is denoted as D. 2t .

[0039] In some embodiments, the travel D of the sliding pin 34 in the groove 36 is... 2t This can be obtained by analyzing the image of the sliding pin 36. Based on stroke D 2t The stroke D of sliding pin 34 in slide groove 35 can be calculated. 1t The stroke D of sliding pin 34 in slide groove 36 2t The stroke D of the slide 35 1t The relationship can be approximated by the following formula:

[0040] D 1t =D 2t cosα (6)

[0041] Based on itinerary D 1t The distal displacement D of the driving wire 4 can be calculated. d For example, if the extension direction of the groove 35 is the same as the movement direction of the drive wire 4, then the distal displacement D d With Itinerary D 1t Equal. If the extending direction of the groove 35 forms an angle β with the moving direction of the drive wire 4, then D d =D 1t cosβ.

[0042] In some embodiments, measurement can be performed using a sensor. Figure 5 The distal displacement of the drive wire 4 of the pliers head 3 is shown. Figure 6 A partial cross-sectional view of the clamp 3 according to some embodiments of the present disclosure is shown. Figure 6 As shown, the distal end of the drive wire 4 is fixedly connected to the slider 37. The slider 37 is fixedly connected to the sliding pin 34. The drive wire 4 drives the slider 37 to reciprocate, which in turn drives the sliding pin 34 to slide in the grooves 35 and 36, thereby controlling the opening and closing of the clamp 3. Figure 6As shown, the clamp head 3 may include a Hall sensor 38. The slider 37 may include a magnetic material. During its movement, the slider 37 cuts the magnetic field of the Hall sensor 38. The Hall sensor 38 can detect the stroke of the slider 37, thereby obtaining the distal displacement D of the drive wire 4. d It should be understood that the clamping device 100 may not include the slider 37, or the slider 37 may not include magnetic material, while the sliding pin 34 may include magnetic material for use with the Hall sensor 38 to measure the distal displacement D of the drive wire 4. d .

[0043] In some embodiments, method 300 may include based on proximal displacement D p and distal displacement D d This determines that the drive wire has deformed. For example, method 300 may include a near-end displacement D. p With distal displacement D d In comparison, and if the proximal displacement D p Greater than the distal displacement D d If this is confirmed, it indicates that the drive wire of the clamping device has deformed.

[0044] Reference Figure 3 In step 307, the elastic force of the drive wire of the clamping device can be calculated. In some embodiments, method 300 may include a proximal displacement D p With distal displacement D d In comparison, and if the proximal displacement D p Greater than the distal displacement D d Then calculate the elastic force of the drive wire of the clamping device.

[0045] For example, based on the proximal displacement D of the driving wire p and distal displacement D d The deformation of the driving wire, ΔL = D, can be calculated. p -D d The elastic force of the driving wire can be calculated based on formula (2):

[0046]

[0047] In step 307, the clamping force of the clamping device can be calculated. For example, the clamping force of the clamping device can be calculated based on formulas (1) and (7).

[0048]

[0049] In some embodiments, the proximal displacement D of the driving wire p The clamping force of the clamping device at time t can be determined by detecting the stroke of the drive motor. Therefore, the clamping force of the clamping device at time t can be calculated using the following formula:

[0050]

[0051] In some embodiments, such as Figure 4-5 As shown, the stroke D of the sliding pin 34 in the slide groove 36 2t This can be obtained by analyzing the image of the sliding pin 36. Based on stroke D 2t The stroke D of the sliding pin 34 in the groove 35 can be calculated according to formula (6). 1t Displacement D at the distal end of the driving wire d With Itinerary D 1t Under approximately equal conditions, the clamping force of the clamping device at time t can be calculated using the following formula:

[0052]

[0053] In some embodiments, by combining formulas (9) and (10), the clamping force of the clamping device at time t can be calculated according to the following formula:

[0054]

[0055] In some embodiments, method 300 may include (e.g., prompting an operator) indicating the clamping force Fg of the clamping device. t The clamping force Fg appears or is indicated. t The relative size (e.g., indicated by color indicator lights) or numerical value. The operator can adjust the operation based on the clamping force cues.

[0056] In some embodiments, method 300 may include maintaining the clamping force of the clamping device at its current value Fg based on (e.g., from an operator) a command to maintain the clamping force. t .

[0057] In some embodiments, method 300 may include applying a clamping force Fg to the clamping device. t With threshold Fg th A comparison is made. Method 300 may include if the clamping force Fg t Greater than the threshold Fg th An alarm signal is issued. Method 300 may further include if the clamping force Fg t Greater than the threshold Fg th Maintain the clamping force of the clamping device at its current value Fg t Since the target object may be human tissue, excessive clamping force can cause damage to the tissue. Alarm signals or clamping force maintenance can mitigate injuries caused by operator error.

[0058] In some embodiments, method 300 may be executed periodically to provide clamping force periodically, or executed in real time to provide clamping force in real time.

[0059] Figure 7 A schematic diagram of a surgical robot system 700 according to some embodiments of the present disclosure is shown. Figure 7 As shown, the surgical robot system 700 may include at least one carriage 10, at least one positioning arm 5, and at least one surgical instrument. At least one positioning arm 5 may be connected to the carriage 10. At least one surgical instrument may be detachably connected to the distal end of the positioning arm 5. The surgical instrument may include surgical tools (e.g., clamping instrument 100) or an endoscope. The clamping instrument 100 may include a drive / transmission unit 1, an arm body 2, a clamp 3, and a drive wire 4 (…). Figure 7 (Not shown in the image).

[0060] In some embodiments, the surgical robot system 700 may include a processor for performing methods according to some embodiments of this disclosure, such as... Figure 3 The method 300 is shown. For example, a surgical robot system 700 may include a memory for storing instructions and a processor coupled to the memory. The processor may execute the instructions stored in the memory to perform a method according to some embodiments of this disclosure, such as... Figure 3 Method 300 is shown.

[0061] In some embodiments, the surgical robot system 700 may include a stroke sensor coupled to a drive motor of a gripping instrument for detecting the stroke of the drive motor. The processor of the surgical robot system 700 may calculate the proximal displacement D of the drive wire based on the stroke detected by the stroke sensor. p .

[0062] In some embodiments, the drive / transmission unit 1 may include a linear transmission device. The linear transmission device may include a screw and a slider rotatably connected to the screw. The screw may be connected to a (built-in or external) drive motor to rotate under the drive of the drive motor. The rotation of the screw can drive the slider to slide linearly along the screw. The drive wire 4 is fixedly connected to the slider to move under the drive of the slider's linear sliding.

[0063] In some embodiments, the proximal displacement sensor may be a stroke sensor coupled to the screw. The processor can calculate the proximal displacement D based on the screw stroke detected by the stroke sensor coupled to the screw. p In some embodiments, the proximal displacement sensor may be a Hall sensor disposed in the drive / transmission unit 1. The slider may include a magnetic material and, during linear sliding along the screw, cuts the magnetic field of the Hall sensor. The Hall sensor can detect the stroke of the slider to obtain the proximal displacement D of the drive wire 4. p .

[0064] In some embodiments, the surgical robot system 700 may include an endoscope for capturing images of a gripping instrument. The processor can analyze the images of the gripping instrument to determine the distal displacement D of the drive wire. d For example, the processor can identify the displacement of the connecting pins of the two jaws of clamp 3 in an image and calculate the distal displacement D of the drive wire. d .

[0065] In some embodiments, the clamping device 100 may include a distal displacement sensor disposed on the clamp 3. For example, the distal displacement sensor may be a Hall sensor disposed on the clamp 3. The connection point, slider, or sliding pin connected to the drive wire 4 may include a magnetic material. During the movement of the drive wire 4, the magnetic material cuts the magnetic field of the Hall sensor. The Hall sensor can detect the travel of the magnetic material, thereby obtaining the distal displacement D of the drive wire 4. d .

[0066] In some embodiments, the processor of the surgical robot system 700 can be based on the proximal displacement D of the drive wire. p and distal displacement D d Calculate the clamping force of the clamping device.

[0067] In some embodiments, the surgical robot system 700 includes an output unit (not shown), such as a display. The output unit can provide the operator with a representation of the clamping force of the clamping instrument, such as a visual color display, a visual numerical display, mechanical vibration, etc.

[0068] In some embodiments, the surgical robot system 700 includes an input unit (not shown) for receiving operating instructions from an operator. The processor can increase or decrease the clamping force of the clamp 3 by controlling a drive motor based on instructions received from the operator to increase or decrease the clamping force of the clamp 3. The processor can also maintain the clamping force of the clamping instrument at its current value Fg based on instructions to maintain the clamping force. t .

[0069] In some embodiments, the processor can control the clamping force Fg of the clamping device. t With threshold Fg th Compare. If the clamping force Fg t Greater than the threshold Fg th The processor can issue an alarm signal or maintain the clamping force of the gripper at its current value Fg. t This prevents damage to human tissue caused by excessive clamping force if the target object is human tissue. In some embodiments, the alarm signal for excessive clamping force may include a change in the color of the clamp image 3 on the display. For example, green indicates normal clamping force, while red indicates that the clamping force exceeds a threshold and may cause damage to the target object.

[0070] Some embodiments of this disclosure can improve the accuracy of clamping force detection for gripping instruments. Furthermore, some embodiments of this disclosure can also improve the operational stability and accuracy of surgical robots, thereby enhancing the safety of surgical procedures.

[0071] Those skilled in the art should understand that this disclosure is not limited to the exemplary embodiments described above. Various changes, adjustments, and substitutions can be made by those skilled in the art without departing from the scope of this disclosure. Therefore, further equivalent embodiments may be included without departing from the concept of this disclosure, and the scope of this disclosure is determined by the scope of the appended claims.

Claims

1. A computer-readable medium having stored thereon instructions which, when executed by a processor, cause a computer to perform a method for determining a clamping force of a clamping instrument, characterized in that, The method comprises: determining a proximal displacement of a drive wire of the clamping instrument, the drive wire being used to drive the clamping instrument to open and close, the drive wire comprising a nitinol wire; determining a distal displacement of the drive wire; calculating a spring force of the drive wire based on the proximal displacement and the distal displacement of the drive wire; and calculating a clamping force of the clamping instrument based on the spring force of the drive wire.

2. The computer-readable medium of claim 1, wherein, The method further comprises: comparing the proximal displacement with the distal displacement; and calculating the spring force of the drive wire in response to the proximal displacement being greater than the distal displacement.

3. The computer-readable medium of claim 1, wherein, The method further comprises: receiving a stroke of a drive motor used to drive the clamping instrument; and calculating the proximal displacement of the drive wire based on the stroke and an initial stroke of the drive motor.

4. The computer-readable medium of claim 1, wherein, The method further comprises: receiving the proximal displacement of the drive wire detected by a sensor.

5. The computer-readable medium of claim 1, wherein, The method further comprises: analyzing an image of the clamping instrument; and determining the distal displacement of the drive wire based on the analysis.

6. The computer-readable medium of claim 1, wherein, The method further comprises: receiving a displacement value detected by a distal displacement sensor disposed on a jaw of the clamping instrument, the drive wire being connected to the jaw to drive the jaw to open and close; and determining the distal displacement of the drive wire based on the displacement value.

7. The computer-readable medium of any of claims 1-6, wherein, The method further comprises: prompting the clamping force of the clamping instrument to appear or displaying a relative size of the clamping force; and / or maintaining the clamping force of the clamping instrument at a current value based on an instruction to maintain the clamping force.

8. The computer readable medium of any of claims 1-6, wherein, The method further comprises displaying a numerical value of the clamping force.

9. The computer-readable medium of any one of claims 1-6, wherein, The method further comprises: comparing the clamping force of the clamping instrument with a threshold value; and issuing an alarm signal and / or maintaining the clamping force at a current value in response to the clamping force being greater than the threshold value.

10. A surgical robotic system comprising: at least one trolley; at least one positioning arm connected to the at least one trolley; at least one surgical instrument detachably connected to a distal end of the at least one positioning arm, the at least one surgical instrument comprising a clamping instrument, the clamping instrument comprising a jaw and a drive wire driving the jaw to open and close, wherein the drive wire comprises a nitinol wire; and a processor configured to perform a method for determining a clamping force of the clamping instrument, the method comprising: determining a proximal displacement of a drive wire of the clamping instrument; determining a distal displacement of the drive wire; calculating a spring force of the drive wire based on the proximal displacement and the distal displacement of the drive wire; and calculating a clamping force of the clamping instrument based on the spring force of the drive wire. The method further comprises:

11. The surgical robotic system of claim 10, wherein, comparing the proximal displacement with the distal displacement; and calculating the spring force of the drive wire in response to the proximal displacement being greater than the distal displacement. The method further comprises:

12. The surgical robotic system of claim 10, wherein, receiving a stroke of a drive motor used to drive the clamping instrument; and calculating the proximal displacement of the drive wire based on the stroke and an initial stroke of the drive motor. The method further comprises:

13. The surgical robotic system of claim 10, wherein, receiving the proximal displacement of the drive wire detected by a sensor. The method further comprises:

14. The surgical robotic system of claim 10, wherein, analyzing an image of the clamping instrument; and determining the distal displacement of the drive wire based on the analysis. The method further comprises: receiving a displacement value detected by a distal displacement sensor disposed on a jaw of the clamping instrument, the drive wire being connected to the jaw to drive the jaw to open and close; and determining the distal displacement of the drive wire based on the displacement value. The method further comprises: prompting the clamping force of the clamping instrument to appear or displaying a relative size of the clamping force; and / or maintaining the clamping force of the clamping instrument at a current value based on an instruction to maintain the clamping force. The method further comprises displaying a numerical value of the clamping force. The method further comprises: comparing the clamping force of the clamping instrument with a threshold value; and issuing an alarm signal and / or maintaining the clamping force at a current value in response to the clamping force being greater than the threshold value. Based on the analysis, the distal displacement of the driving wire is determined.

15. The surgical robotic system of claim 10, wherein, The method further comprises: receiving a displacement value detected by a distal displacement sensor arranged on the clamping instrument; Based on the displacement value, the distal displacement of the driving wire is determined.

16. The surgical robotic system of any of claims 10-15, wherein, The method further comprises: prompting the occurrence of the clamping force of the clamping instrument or displaying the relative size of the clamping force; and / or Based on the instruction to maintain the clamping force, the clamping force of the clamping instrument is maintained at the current value.

17. The surgical robotic system of any of claims 10-15, wherein, The method further comprises displaying the numerical value of the clamping force.

18. The surgical robotic system of any of claims 10-15, wherein, The method further comprises: comparing the clamping force of the clamping instrument with a threshold value; and in response to the clamping force being greater than the threshold value, issuing an alarm signal and / or maintaining the clamping force at the current value.

19. The surgical robotic system of claim 10, wherein, Further comprising: a travel sensor coupled to the driving motor of the clamping instrument for detecting the travel of the driving motor.

20. The surgical robotic system of claim 10, wherein, The clamping instrument further comprises: a driving / transmission unit comprising a linear transmission device, the linear transmission device comprising a screw rod and a sliding block rotationally connected to the screw rod, the driving wire being fixedly connected to the sliding block; and a travel sensor coupled to the screw rod for detecting the travel of the screw rod, and the processor is configured to calculate the proximal displacement of the driving wire based on the detected travel of the screw rod; or a Hall sensor arranged in the driving / transmission unit for detecting the travel of the sliding block, the sliding block comprising a magnetic material.

21. The surgical robotic system of claim 10, wherein, The at least one surgical instrument comprises an endoscope for taking images of the clamping instrument.

22. The surgical robotic system of claim 21, wherein, The clamping jaws comprise: a first jaw comprising a first sliding groove; a second jaw rotationally connected to the first jaw and comprising a second sliding groove cooperating with the first sliding groove; and a sliding pin fixedly connected to the driving wire and slidable in the first sliding groove and the second sliding groove, the processor is configured to determine the travel of the sliding pin in the second sliding groove based on the taken images, and calculate the distal displacement of the driving wire based on the travel.

23. The surgical robotic system of claim 10, wherein, The clamping instrument comprises a Hall sensor arranged on the clamping jaws for detecting the distal displacement of the driving wire, the connection point, the sliding block or the sliding pin connected to the distal end of the driving wire comprising a magnetic material.

24. The surgical robotic system of claim 10, wherein, Further comprising: an output unit for providing the clamping force of the clamping instrument; or an input unit for receiving an operation instruction, the processor being configured to increase or decrease the clamping force representation of the clamping jaws by controlling the driving motor of the clamping instrument based on the operation instruction, or the processor being configured to maintain the clamping force of the clamping jaws at the current value based on the operation instruction to maintain the clamping force.

Images