Saw Blade Bending Measurement Method, Calibration Method of Surgical Robot, and Surgical Robot

Abstract

An embodiment of the present invention provides a method for measuring the bending of a saw blade, a calibration method for a surgical robot, and a surgical robot, which relate to the field of control technology. The method for measuring the bending of a saw blade includes: on each plane of the saw blade, controlling a tracking pressure probe to apply a continuously changing pressure to the end of the plane away from the pressure sensor, and acquiring the pressure values collected by the pressure sensors with changing values and the spatial positions of the saw blade recorded by the corresponding tracking pressure probes; for each pressure sensor, based on the pressure values collected by the pressure sensor and the spatial positions of the saw blade recorded by the corresponding tracking pressure probe, obtaining the relationship between the pressure change value of the pressure sensor and the spatial position change value of the corresponding saw blade. In the present invention, the relationship between the pressure change value of the pressure sensor and the corresponding bending value of the saw blade can be obtained, which is convenient for calibrating the bending of the saw blade during subsequent surgical procedures.

Description

Technical Field

[0001] The present invention relates to the field of control technology, and particularly to a method for measuring the bending of a saw blade, a calibration method for a surgical robot, and a surgical robot. Background Art

[0002] Total Knee Replacement (TKR) is one of the most effective surgeries for solving severe knee lesions that affect the patient's motor function, and can effectively improve the patient's quality of life. However, the current traditional artificial knee replacement surgery highly depends on the experience of clinicians, and the failure rates due to prosthesis loosening, dislocation, fracture, and infection noise reach 5% - 8%. Compared with the traditional artificial knee replacement surgery, the knee replacement surgical robot combines computer image processing with precise robot planning, conducts intelligent evaluation of force and motion analysis, and assists clinicians in completing knee replacement surgery, which can reduce surgical trauma, shorten the surgical time, and improve the surgical success rate and quality.

[0003] The knee replacement surgical robot can achieve bone saw positioning and operation by using a six-axis collaborative robotic arm in parallel with a bone saw. The sawing plane is locked by the collaborative robotic arm to ensure that the movement of the bone saw only occurs on the plane locked by the collaborative robotic arm, and the user completes the movement of the bone saw and the osteotomy operation.

[0004] However, for total knee replacement surgery, high precision is required. However, the human bone has a certain hardness, especially for patients with severe sclerosis. The saw blade of the bone saw often bends at a certain angle during bone sawing, which has a great impact on the accuracy of knee replacement surgery. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for measuring the bending of a saw blade, a calibration method for a surgical robot, and a surgical robot, which can obtain the relationship between the pressure change value of a pressure sensor and the corresponding bending value of the saw blade. During subsequent surgery, when the saw blade in the surgical robot performs surgery, the pressure received by the saw blade is obtained in real time through the pressure sensor, and based on the relationship between the pressure change value of the pressure sensor and the corresponding bending value of the saw blade, the bending error of the saw blade can be calculated, a prompt warning can be given in real time, and the bending error can be corrected by controlling the collaborative robotic arm in the surgical robot, reducing the probability of surgical accidents, improving the accuracy of the surgery, and helping to improve the surgical success rate.

[0006] To achieve the above object, the present invention provides a method for measuring the bending of a saw blade. Two pressure sensors are respectively arranged on both sides of the fixed part of the bone saw and the saw blade. The two pressure sensors are located in the same plane of the saw blade and are in contact with the saw blade. The method includes: on each plane of the saw blade, controlling a tracking pressure probe to apply a continuously changing pressure to one end of the plane away from the pressure sensor, and acquiring the pressure value collected by the pressure sensor whose value changes and the spatial position of the saw blade recorded by the corresponding tracking pressure probe; for each of the pressure sensors, based on the pressure value collected by the pressure sensor and the spatial position of the saw blade recorded by the corresponding tracking pressure probe, obtaining the relationship between the pressure change value of the pressure sensor and the spatial position change value of the corresponding saw blade.

[0007] The present invention also provides a calibration method for a surgical robot. In the surgical robot, two pressure sensors are respectively arranged on both sides of the fixed part of the bone saw and the saw blade. The two pressure sensors are located in the same plane of the saw blade and are in contact with the saw blade. The method includes: during the operation of the surgical robot, real-time acquiring the pressure values collected by the two pressure sensors; for the pressure sensor whose pressure value changes, based on the preset relationship between the pressure change value of the pressure sensor and the spatial position change value of the saw blade, obtaining the current spatial position change value of the saw blade corresponding to the current pressure change value of the pressure sensor, where the relationship between the pressure change value of the pressure sensor and the spatial position change value of the saw blade is obtained based on the above method for measuring the bending of the saw blade; based on the current spatial position change value of the saw blade, calibrating the spatial position of the saw blade.

[0008] The present invention also provides a surgical robot, including: a control device, a collaborative robotic arm, a bone saw, a saw blade, and two pressure sensors; the control device is respectively communicatively connected to the collaborative robotic arm and the two pressure sensors; the bone saw is fixed on the collaborative robotic arm, the saw blade is fixed on the bone saw, the two pressure sensors are respectively arranged on both sides of the fixed part of the bone saw and the saw blade, the two pressure sensors are located in the same plane of the saw blade and are in contact with the saw blade, and the control device is used to execute the above calibration method for the surgical robot.

[0009] In an embodiment of the present invention, on each plane of the saw blade, a continuously changing pressure is applied to one end of the plane away from the pressure sensor by a tracking pressure probe, and the pressure value collected by the pressure sensor with a changing value and the spatial position of the saw blade recorded by the corresponding tracking pressure probe are obtained. That is, the external force received by the saw blade during operation is simulated by the tracking pressure probe, and the pressure received by the saw blade and the bending value of the saw blade are recorded by the pressure sensor. Since pressure may be applied to both planes of the saw blade, two tests of applying pressure are respectively performed on the two planes of the saw blade; subsequently, for each pressure sensor, based on the pressure value collected by the pressure sensor and the spatial position of the saw blade recorded by the corresponding tracking pressure probe, the relationship between the pressure change value of the pressure sensor and the spatial position change value of the corresponding saw blade is obtained. That is, using the recorded pressure received by the pressure sensor of the saw blade and the bending value of the saw blade, the relationship between the pressure change value of the pressure sensor and the corresponding bending value of the saw blade is solved. During subsequent surgery, when the saw blade in the surgical robot performs surgery, the pressure received by the saw blade is obtained in real time through the pressure sensor, and based on the relationship between the pressure change value of the pressure sensor and the corresponding bending value of the saw blade, the bending error of the saw blade can be calculated, a prompt warning can be given in real time, and the bending error can be corrected by controlling the cooperative robotic arm in the surgical robot, reducing the probability of surgical accidents, improving the accuracy of the surgery, and helping to improve the success rate of the surgery.

[0010] In one embodiment, for each pressure sensor, based on the pressure value collected by the pressure sensor and the spatial position of the saw blade recorded by the corresponding tracking pressure probe, obtaining the relationship between the pressure change value of the pressure sensor and the spatial position change value of the corresponding saw blade includes: for each pressure sensor, establishing a relational expression between the pressure change value of the pressure sensor and the spatial position change value of the corresponding saw blade recorded by the tracking pressure probe; for each pressure sensor, based on the recorded pressure value of the pressure sensor and the spatial position of the saw blade recorded by the corresponding tracking pressure probe, solving the relational expression between the pressure change value of the pressure sensor and the spatial position change value of the corresponding saw blade recorded by the tracking pressure probe.

[0011] In one embodiment, the relational expression between the pressure change value of the pressure sensor and the spatial position change value of the corresponding saw blade recorded by the tracking pressure probe is:

[0012] ΔN i =a·Δd i 2 +b·Δd i +c;

[0013] ΔNi = N i -N 0 ;

[0014] Δd i = dis(P i , P 0 );

[0015] Wherein, ΔN i represents the i-th pressure change value of the pressure sensor, N i represents the i-th pressure value recorded by the pressure sensor, N 0 represents the initial pressure value of the pressure sensor, Δd i represents the i-th spatial position change value of the saw blade recorded by the tracking pressure probe, P i represents the i-th spatial position of the saw blade recorded by the tracking pressure probe, P 0 represents the initial spatial position of the saw blade recorded by the tracking pressure probe, i = 1, 2, 3,..., n, n is the total number of recorded data, and a, b, and c are all parameters to be solved.

[0016] In one embodiment, the initial pressure value of the pressure sensor is the pressure value of the pressure sensor when it is in contact with the saw blade.

[0017] In one embodiment, when the tracking pressure probe is in contact with the plane of the saw blade and the two pressure sensors maintain the initial pressure value, the tracking pressure probe records the initial spatial position of the saw blade.

[0018] In one embodiment, for each of the pressure sensors, based on the recorded pressure value of the pressure sensor and the spatial position of the saw blade recorded by the corresponding tracking pressure probe, solving the relationship between the pressure change value of the pressure sensor and the spatial position change value of the saw blade recorded by the corresponding tracking pressure probe includes: for each of the pressure sensors, based on the recorded pressure value of the pressure sensor and the spatial position of the saw blade recorded by the corresponding tracking pressure probe, using the least squares method to solve the relationship between the pressure change value of the pressure sensor and the spatial position change value of the saw blade recorded by the corresponding tracking pressure probe.

[0019] In one embodiment, control the direction in which the tracking pressure probe applies a continuously changing pressure to the plane to be perpendicular to the plane of the saw blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1Schematic diagram of the fixing method of the saw blade, bone saw and two pressure sensors applied in the saw blade bending measurement method according to the first embodiment of the present invention;

[0021] Figure 2 Specific flowchart of the saw blade bending measurement method according to the first embodiment of the present invention;

[0022] Figure 3 Is Figure 2 Specific flowchart of step 102 of the saw blade bending measurement method in;

[0023] Figure 4 Schematic diagram of applying pressure on the upper plane of the saw blade by the tracking pressure probe according to the first embodiment of the present invention;

[0024] Figure 5 Is the pressure change value of the pressure sensor when the upper plane of the saw blade is under pressure according to the first embodiment of the present invention And the spatial position change value Δd of the saw blade recorded by the corresponding tracking pressure probe i Schematic diagram of the relationship between;

[0025] Figure 6 Is the pressure change value of the pressure sensor when the lower plane of the saw blade is under pressure according to the first embodiment of the present invention And the spatial position change value Δd of the saw blade recorded by the corresponding tracking pressure probe i Schematic diagram of the relationship between;

[0026] Figure 7 Specific flowchart of the calibration method of the surgical robot according to the second embodiment of the present invention;

[0027] Figure 8 Block diagram of the surgical robot according to the third embodiment of the present invention;

[0028] Figure 9 Mechanical structure diagram of the surgical robot according to the third embodiment of the present invention. Detailed description of the specific implementation

[0029] The following will describe each embodiment of the present invention in detail with reference to the accompanying drawings, so as to more clearly understand the purpose, features and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not limitations on the scope of the present invention, but only to illustrate the essential spirit of the technical solution of the present invention.

[0030] In the following description, certain specific details are set forth in order to provide a thorough understanding of the various disclosed embodiments. However, one skilled in the relevant art will recognize that the embodiments may be practiced without one or more of these specific details. In other instances, well-known devices, structures, and techniques associated with the present application may not be shown or described in detail so as not to unnecessarily obscure the description of the embodiments.

[0031] Unless the context requires otherwise, throughout the specification and claims, the words "comprise" and its variations such as "comprising" and "having" shall be understood in an open, inclusive sense, i.e., to mean "including, but not limited to".

[0032] References to "one embodiment" or "an embodiment" in the course of this specification mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Additionally, the particular features, structures, or characteristics may be combined in any manner in one or more embodiments.

[0033] As used in this specification and the appended claims, the singular forms "a" and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally used in its "and / or" sense unless the context clearly dictates otherwise.

[0034] In the following description, in order to clearly show the structure and working mode of the present invention, many directional terms will be used for description. However, words such as "front", "rear", "left", "right", "outside", "inside", "outward", "inward", "up", and "down" should be understood as convenient terms and should not be construed as limiting terms.

[0035] The first embodiment of the present invention relates to a method for measuring the bending of a saw blade, which is used to measure the bending degree of the saw blade in a surgical robot (such as a knee replacement surgical robot) so as to correct the bending of the saw blade in real time during the surgical process of the surgical robot. In the surgical robot, a bone saw is mounted on a collaborative robotic arm, the saw blade is fixed to the bone saw, and two pressure sensors are respectively arranged on both sides of the fixing position of the bone saw and the saw blade. The two pressure sensors are located in the same plane of the saw blade and are in contact with the saw blade. Please refer to Figure 1, the saw blade 1 is fixed on the bone saw 2. The bone saw 2 is provided with a limiting part 21 for limiting the saw blade 1. Two pressure sensors are arranged along the length direction of the saw blade, and the two pressure sensors are respectively arranged on both sides of the limiting part 21. The pressure sensor arranged on the left side of the limiting part 21 is denoted as the pressure sensor 31, and the pressure sensor arranged on the right side of the limiting part 21 is denoted as the pressure sensor 32. Among them, the two pressure sensors can be arranged perpendicular to the plane of the saw blade 1.

[0036] The specific process of the saw blade bending measurement method in this embodiment is as Figure 2 shown.

[0037] Step 101, on each plane of the saw blade, control the tracking pressure probe to apply a continuously changing pressure to the end of the plane away from the pressure sensor, and obtain the pressure value collected by the pressure sensor whose value changes and the spatial position of the saw blade recorded by the corresponding tracking pressure probe.

[0038] Step 102, for each pressure sensor, based on the pressure value collected by the pressure sensor and the spatial position of the saw blade recorded by the corresponding tracking pressure probe, obtain the relationship between the pressure change value of the pressure sensor and the spatial position change value of the corresponding saw blade.

[0039] In one example, please refer to Figure 3 , step 102 includes the following sub-steps:

[0040] Sub-step 1021, for each pressure sensor, establish a relational expression between the pressure change value of the pressure sensor and the spatial position change value of the corresponding saw blade recorded by the tracking pressure probe.

[0041] Specifically, the relational expression between the pressure change value of the pressure sensor and the spatial position change value of the corresponding saw blade recorded by the tracking pressure probe is:

[0042] ΔN i =a·Δd i 2 +b·Δd i +c;

[0043] ΔN i =N i -n 0 ;

[0044] Δd i =dis(P i ,P 0 );

[0045] Among them, ΔN i represents the i-th pressure change value of the pressure sensor, N i represents the i-th pressure value of the recorded pressure sensor, N0 represents the initial pressure value of the pressure sensor, Δd i represents the change value of the i-th spatial position of the saw blade recorded by the tracking pressure probe, P i represents the i-th spatial position of the saw blade recorded by the tracking pressure probe, P 0 represents the initial spatial position of the saw blade recorded by the tracking pressure probe, i = 1, 2, 3,..., n, where n is the total number of recorded data, and a, b, and c are all parameters to be solved.

[0046] Sub-step 1022: For each pressure sensor, based on the pressure value of the recorded pressure sensor and the spatial position of the saw blade recorded by the corresponding tracking pressure probe, solve the relationship between the pressure change value of the pressure sensor and the change value of the spatial position of the saw blade recorded by the corresponding tracking pressure probe.

[0047] The following details the saw blade bending measurement method in this embodiment.

[0048] After the saw blade 1 is installed on the bone saw 2 and two pressure sensors (including pressure sensor 31 and pressure sensor 32) are in contact with the plane of the saw blade 1, the two pressure sensors can be set perpendicular to the plane of the saw blade 1. Thus, the pressure sensors can receive the force perpendicular to the plane of the saw blade 1, that is, the pressure sensors can collect the pressure on the contact surface between the plane and the pressure sensors. The pressure sensors are connected to the control device of the surgical robot (such as electronic devices like a computer host, a tablet computer, a mobile phone, etc.), and will send the collected pressure to the control device. Among them, when the saw blade 1 is installed on the bone saw 2 and the bone saw remains stationary and is mechanically locked, the control device will take the current pressure values collected by the two pressure sensors as the initial pressure values of the two pressure sensors. The initial pressure value of pressure sensor 31 is The initial pressure value of pressure sensor 32 is

[0049] The control device uses the robotic arm to drive the tracking pressure probe to apply a continuously changing pressure at one end of the saw blade 1 away from the pressure sensors twice to simulate the upward or downward bending of the saw blade 1 when it is stressed.

[0050] Please refer to Figure 4 , taking the test of the upper plane of the saw blade 1 by the tracking pressure probe 4 as an example. The control device controls the robotic arm to drive the tracking pressure probe 5 to contact one end of the upper plane of the saw blade 1 away from the pressure sensors. A tracker for obtaining the spatial position of the tracking pressure probe is assembled on the tracking pressure probe 4. When the tracking pressure probe 4 is in full contact with the upper plane of the saw blade 1 and the values of the two pressure sensors do not change and remain the initial pressure values, the tracker will take the collected spatial position of the tracking pressure probe 4 as its initial spatial position P 0 (x0 , y 0 , z 0 ), at this time, the tracking pressure probe 4 does not apply pressure to the saw blade 1, so the initial spatial position P of the tracking pressure probe 0 (x 0 , y 0 , z 0 ) is the initial spatial position of the saw blade 1.

[0051] Subsequently, the control device controls the robotic arm to drive the tracking pressure probe 4 to apply a continuously changing pressure (such as a continuously increasing pressure) to the upper plane of the saw blade 1. The direction of controlling the tracking pressure probe 4 to apply a continuously changing pressure to the plane is perpendicular to the plane of the saw blade. When the tracking pressure probe 4 applies a downward pressure to the upper plane of the saw blade 1, the saw blade 1 will bend downward. The greater the pressure applied by the tracking pressure probe 4 to the upper plane of the saw blade 1, the greater the bending degree of the saw blade 1. The tracking pressure probe 4 will record the spatial position of the tracking pressure probe 4 in real time, that is, record the spatial position P of the saw blade 1 i (x i , y i , z i ), i = 1, 2, … n, and the spatial position P of the saw blade 1 i (x i , y i , z i ) is sent to the control device in real time.

[0052] Based on the fixing method of the saw blade 1 and the bone saw 2, when the saw blade 1 bends downward and deforms, the part of the saw blade 1 on the right side of the limiting part 21 will bend upward. At this time, the value of the pressure sensor 32 changes, and the value of the pressure sensor 31 does not change. Since the pressure applied by the tracking pressure probe 4 to the upper plane of the saw blade 1 is continuously changing, the pressure value collected by the pressure sensor 32 is also continuously changing. The pressure sensor 32 will collect the pressure value according to the preset collection frequency to obtain and the collected pressure value is sent to the control device; among them, the tracker and the pressure sensor 32 collect information at the same frequency, that is, the tracker and the pressure sensor 32 collect and send information to the control device at the same time. It should be noted that there is a certain angle between the pressure collected by the pressure sensor 32 and the upper plane of the saw blade 1, then the force perpendicular to the upper plane of the saw blade 1 can be calculated as the pressure value detected by the pressure sensor 32 and sent to the control device.

[0053] When the control device receives the n data information sent by the tracker and the pressure sensor 32, it is defined that the pressure change value of the pressure sensor 32 is where Represents the i-th pressure change value of the pressure sensor 32, Represents the i-th pressure value of the recorded pressure sensor 32, Represents the initial pressure value of the pressure sensor, where i = 1, 2, 3, …, n, and n is the total number of recorded data.

[0054] Define the spatial position change value of the saw blade 1 as Δd i , where, Δd i Represents the i-th spatial position change value of the saw blade recorded by the tracking pressure probe, P i Represents the i-th spatial position of the saw blade recorded by the tracking pressure probe, with the coordinates represented as (x i , y i , z i ), P 0 Represents the initial spatial position of the saw blade recorded by the tracking pressure probe, with the coordinates represented as (x 0 , y 0 , z 0 ), where i = 1, 2, 3, …, n, and n is the total number of recorded data.

[0055] Establish a relationship between the pressure change value of the pressure sensor 32 and the corresponding spatial position change value of the saw blade 1 recorded by the tracking pressure probe, specifically as follows:

[0056]

[0057] where a, b, and c are all parameters to be solved.

[0058] Subsequently, the above relationship can be solved based on the pressure change values of n pressure sensors 32 and the spatial position change values of n saw blades 1. The solution method is, for example, the least squares method, specifically as follows:

[0059] The objective function is:

[0060] The linear regression model is defined as: h i (x 1 , x 2 ) = c + b·x 1,i + a·x 2,i ;

[0061] where, x 1,i = Δd i ,

[0062] Substitute n samples of Δd i into the linear regression model, and we can get:

[0063] h1 = c + b·x 1,1 + a·x 2,1

[0064] h 2 = c + b·x 1,2 + a·x 2,2

[0065] ……

[0066] h n = c + b·x 1,n + a·x 2,n

[0067] Let x 0 = 1, the above equation can be transformed into matrix representation:

[0068] h = DL

[0069] where h is an n×1 vector representing the theoretical value of the linear regression model, D is an n×3 matrix, n represents the number of samples, and L is a 3×1 vector representing the vector composed of c, b, and a to be solved.

[0070] The above objective function is represented in matrix form as:

[0071] ||h - Y|| 2 = ||DL - Y|| 2 = (DL - Y) T (DL - Y)

[0072] where Y represents a one-dimensional vector composed of n components.

[0073] Simplify the objective function represented in matrix form:

[0074] (DL - Y) T (DL - Y) = L T D T DL - L T D T Y - Y T DL + Y T Y

[0075] Take the derivative of the simplified objective function and set it equal to 0.

[0076] 2D T DL - 2D T Y = 0

[0077] Furthermore, solve for L = (D T D) -1 D T Y.

[0078] Subsequently, n and n Δd i Substitute into the above formula for L, and L can be obtained, that is, the values of the three parameters a, b, and c are solved. From this, the relationship between the pressure change value of the pressure sensor 32 and the spatial position change value of the saw blade 1 recorded by the corresponding tracking pressure probe 4 can be obtained. As Figure 5 shown, when the upper plane of the saw blade 1 is subjected to pressure, the pressure change value of the pressure sensor 32 and the spatial position change value Δd of the saw blade 1 recorded by the corresponding tracking pressure probe 4 i are shown in the schematic diagram of the relationship between them.

[0079] The above takes Figure 4 the test of applying pressure to the upper plane of the saw blade 1 by the tracking pressure probe 4 as an example for explanation. Similarly, in the same way as the above process, the tracking pressure probe 4 can be controlled to apply pressure to the lower plane of the saw blade 1 for testing. At this time, the value of the pressure sensor 3 changes, and the pressure change value of the pressure sensor 31 can be obtained and the relationship formula between the spatial position change value of the saw blade 1 recorded by the corresponding tracking pressure probe 4 where e, f, and j are the three parameters obtained by solving. As Figure 6 shown, when the lower plane of the saw blade 1 is subjected to pressure, the pressure change value of the pressure sensor 31 and the spatial position change value Δd of the saw blade 1 recorded by the corresponding tracking pressure probe 4 i are shown in the schematic diagram of the relationship between them.

[0080] In this embodiment, on each plane of the saw blade, the tracking pressure probe is controlled to apply a continuously changing pressure to the end of the plane away from the pressure sensor, and the pressure value collected by the pressure sensor with a changing value and the spatial position of the saw blade recorded by the corresponding tracking pressure probe are obtained. That is, the external force received by the saw blade during operation is simulated by the tracking pressure probe, and the pressure received by the saw blade and the saw blade bending value are recorded by the pressure sensor. Since both planes of the saw blade may be subjected to pressure, two tests of applying pressure are respectively performed on the two planes of the saw blade. Subsequently, for each pressure sensor, based on the pressure value collected by the pressure sensor and the spatial position of the saw blade recorded by the corresponding tracking pressure probe, the relationship between the pressure change value of the pressure sensor and the spatial position change value of the corresponding saw blade is obtained. That is, using the pressure received by the saw blade of the recorded pressure sensor and the saw blade bending value, the relationship between the pressure change value of the pressure sensor and the corresponding saw blade bending value is solved. During subsequent surgery of the saw blade in the surgical robot, the pressure received by the saw blade is obtained in real time through the pressure sensor, and based on the relationship between the pressure change value of the pressure sensor and the corresponding saw blade bending value, the bending error of the saw blade can be calculated, a prompt warning can be given in real time, and the bending error can be corrected by controlling the collaborative robotic arm in the surgical robot, reducing the probability of surgical accidents, improving the accuracy of the surgery, and helping to improve the success rate of the surgery.

[0081] The second embodiment of the present invention relates to a calibration method for a surgical robot, which is applied to the control device of the surgical robot. In the surgical robot, two pressure sensors are respectively arranged on both sides of the fixed part of the bone saw and the saw blade, and the two pressure sensors are located on the same plane of the saw blade and are in contact with the saw blade, as Figure 1 shown.

[0082] The specific process of the calibration method for the surgical robot in this embodiment is as Figure 7 shown.

[0083] Step 201, during the operation of the surgical robot, the pressure values collected by the two pressure sensors are obtained in real time.

[0084] Step 202, for the pressure sensor with a changing pressure value, based on the preset relationship between the pressure change value of the pressure sensor and the spatial position change value of the saw blade, the current spatial position change value of the saw blade corresponding to the current pressure change value of the pressure sensor is obtained, where the relationship between the pressure change value of the pressure sensor and the spatial position change value of the saw blade is obtained based on the saw blade bending measurement method in the first embodiment.

[0085] Step 203, based on the current spatial position change value of the saw blade, the spatial position of the saw blade is calibrated.

[0086] Specifically, the control device of the surgical robot presets the relationship between the pressure change values of the two pressure sensors and the spatial position change values of the saw blade, that is, the corresponding relationship between the pressure change value of each pressure sensor and the bending value of the saw blade is preset in the control device.

[0087] During the process of the saw blade of the surgical robot performing bone sawing surgery, the two pressure sensors will collect pressure in real time and send the currently collected pressure values to the control device. The two pressure sensors respectively reflect the pressures received by the two planes of the saw blade, thereby enabling correction of the bending of the saw blade in two directions perpendicular to the saw blade respectively.

[0088] Taking Figure 1 the pressure sensor 32 in as an example, the control device of the surgical robot presets the relationship between the pressure change value of the pressure sensor 32 and the spatial position change value of the saw blade 1, that is, the relational formula between the pressure change value of the pressure sensor 32 and the spatial position change value of the saw blade 1 recorded by the corresponding tracking pressure probe 4 is preset

[0089] For the currently collected pressure value sent by the pressure sensor 32, the control device 1 will compare the currently collected pressure value sent by the pressure sensor 32 with the initial pressure value of the preset pressure sensor 32, calculate the current pressure change value, and then substitute the current pressure change value into the above relational formula to obtain the spatial position change value of the saw blade 1 corresponding to the current pressure change value, which is equivalent to obtaining the bending value of the saw blade 1. The bending value of the saw blade 1 represents the bending error generated by the force exerted by the bone on the saw blade. Subsequently, the control device controls the cooperative robotic arm to drive the bone saw 2 to correct the spatial position of the saw blade 1, so as to compensate for the current bending error of the saw blade 1, improve the accuracy of the operation of the saw blade 1, and offset the adverse effects brought by the bending error of the saw blade 1 to the surgery.

[0090] In this embodiment, when the saw blade in the surgical robot performs surgery, the pressure received by the saw blade is obtained in real time through the pressure sensor, and based on the relationship between the pressure change value of the preset pressure sensor and the corresponding bending value of the saw blade, the bending error of the saw blade can be calculated, a prompt warning can be given in real time, and the bending error can be corrected by controlling the cooperative robotic arm in the surgical robot, reducing the probability of surgical accidents, improving the accuracy of the surgery, and helping to improve the success rate of the surgery.

[0091] The third embodiment of the present invention relates to a surgical robot, for example, a knee joint replacement surgical robot. Please refer to Figure 1 、 Figure 8 and Figure 9, comprising: a saw blade 1, a bone saw 2, two pressure sensors, a control device 5, and a collaborative robotic arm 6; the control device is an electronic device such as a computer mainframe, a tablet computer, a mobile phone, etc., and the control device 5 is communicatively connected to the collaborative robotic arm 6 and the two pressure sensors respectively (for example, connected by a data cable); the bone saw 2 is fixed on the collaborative robotic arm 6, the saw blade 1 is fixed on the bone saw 2, the two pressure sensors are respectively arranged on both sides of the fixing position of the bone saw 2 and the saw blade 2, the two pressure sensors are located in the same plane as the saw blade 1 and are in contact with the saw blade 1. Among them, in Figure 9 , only a partial structure of the collaborative robotic arm 6 is schematically shown, and the collaborative robotic arm 6 is connected to the bone saw 2 through a passive two-link; the bone saw 2 has a limiting portion 21, and the limiting portion 21 is used to limit the saw blade 1, and the two pressure sensors are respectively arranged on both sides of the limiting portion 21. The pressure sensor arranged on the left side of the limiting portion 21 is denoted as the pressure sensor 31, and the pressure sensor arranged on the right side of the limiting portion 21 is denoted as the pressure sensor 32; among them, the two pressure sensors can be arranged perpendicular to the plane of the saw blade 1.

[0092] The control device 5 is used to execute the calibration method of the surgical robot in the second embodiment.

[0093] The preferred embodiments of the present invention have been described in detail above, but it should be understood that, if necessary, aspects of the embodiments can be modified to adopt aspects, features, and concepts of various patents, applications, and publications to provide additional embodiments.

[0094] In view of the above detailed description, these and other changes can be made to the embodiments. Generally speaking, in the claims, the terms used should not be considered as limited to the specific embodiments disclosed in the specification and the claims, but should be understood to include all possible embodiments together with the full equivalent scope enjoyed by these claims.

Claims

1. A method for measuring the bending of a saw blade, characterized in that, two pressure sensors are respectively arranged on both sides of the fixing position of the bone saw and the saw blade, the two pressure sensors are located in the same plane as the saw blade and are in contact with the saw blade, and the method includes: On each plane of the saw blade, control the tracking pressure probe to apply a continuously changing pressure to one end of the plane away from the pressure sensor, and obtain the pressure value collected by the pressure sensor whose value changes and the spatial position of the saw blade recorded by the corresponding tracking pressure probe; For each of the pressure sensors, based on the pressure value collected by the pressure sensor and the spatial position of the saw blade recorded by the corresponding tracking pressure probe, obtain the relationship between the pressure change value of the pressure sensor and the corresponding spatial position change value of the saw blade.

2. The method for measuring the bending of a saw blade according to claim 1, characterized in that, For each of the pressure sensors, based on the pressure value collected by the pressure sensor and the spatial position of the saw blade recorded by the corresponding tracking pressure probe, obtaining the relationship between the pressure change value of the pressure sensor and the corresponding spatial position change value of the saw blade includes: For each of the pressure sensors, establish a relational expression between the pressure change value of the pressure sensor and the corresponding spatial position change value of the saw blade recorded by the tracking pressure probe; For each of the pressure sensors, based on the recorded pressure value of the pressure sensor and the spatial position of the saw blade recorded by the corresponding tracking pressure probe, solve the relational expression between the pressure change value of the pressure sensor and the corresponding spatial position change value of the saw blade recorded by the tracking pressure probe.

3. The method for measuring the bending of a saw blade according to claim 2, characterized in that, The relational expression between the pressure change value of the pressure sensor and the corresponding spatial position change value of the saw blade recorded by the tracking pressure probe is: ΔN i = a·Δd i 2 + b·Δd i + c; ΔN i = N i - N 0 ; Δd i = dis(P i , P 0 ); where, ΔN i represents the i-th pressure change value of the pressure sensor, N i represents the recorded i-th pressure value of the pressure sensor, N 0 represents the initial pressure value of the pressure sensor, Δd i represents the i-th spatial position change value of the saw blade recorded by the tracking pressure probe, P i represents the i-th spatial position of the saw blade recorded by the tracking pressure probe, P 0 represents the initial spatial position of the saw blade recorded by the tracking pressure probe, i = 1, 2, 3, …, n, where n is the total number of recorded data, and a, b, and c are all parameters to be solved.

4. The method for measuring the bending of a saw blade according to claim 3, characterized in that, The initial pressure value of the pressure sensor is the pressure value of the pressure sensor when it is in contact with the saw blade.

5. The method for measuring the bending of a saw blade according to claim 3, characterized in that, When the tracking pressure probe is in contact with the plane of the saw blade and the two pressure sensors maintain the initial pressure value, the tracking pressure probe records the initial spatial position of the saw blade.

6. The method for measuring the bending of a saw blade according to claim 2, characterized in that, For each of the pressure sensors, based on the recorded pressure value of the pressure sensor and the spatial position of the saw blade recorded by the corresponding tracking pressure probe, solving the relational expression between the pressure change value of the pressure sensor and the corresponding spatial position change value of the saw blade recorded by the tracking pressure probe includes: For each of the pressure sensors, based on the recorded pressure values of the pressure sensors and the corresponding spatial positions of the saw blade recorded by the tracking pressure probes, the least squares method is used to solve the relationship between the pressure change values of the pressure sensors and the corresponding spatial position change values of the saw blade recorded by the tracking pressure probes.

7. The saw blade bending measurement method according to claim 1, wherein, the direction of controlling the tracking pressure probe to apply a continuously changing pressure to the plane is perpendicular to the plane of the saw blade.

8. A surgical robot, wherein, comprising: a control device, a collaborative robotic arm, a bone saw, a saw blade, and two pressure sensors; the control device is respectively communicatively connected to the collaborative robotic arm and the two pressure sensors; the bone saw is fixed on the collaborative robotic arm, the saw blade is fixed on the bone saw, the two pressure sensors are respectively arranged on both sides of the fixing position of the bone saw and the saw blade, the two pressure sensors are located in the same plane as the saw blade and are in contact with the saw blade, and the control device is configured to execute the saw blade bending measurement method according to any one of claims 1-7.

9. The surgical robot according to claim 8, wherein, the surgical robot is a knee joint replacement surgical robot.

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