Orthopedic surgery robot boundary control method, device and equipment and storage medium

Abstract

The application provides a boundary control method, device and equipment of an orthopedic surgery robot and a storage medium, comprising: acquiring a current pose of the end of a surgical tool and a desired pose of the end of the surgical tool, the desired pose being a pose that the end of the surgical tool is expected to reach at a next time; acquiring a current reference pose of a patient's acetabulum; determining a safe pose of the end of the surgical tool at the next time according to the current pose, the desired pose and the reference pose; and controlling the movement of the surgical tool according to the current pose and the safe pose. The problem that the acetabular file is prone to excessive movement range, resulting in excessive acetabular grinding and reduced surgical precision, is solved when the robot assists the doctor in acetabular grinding.

Description

Technical Field

[0001] This application relates to the field of medical instrument technology, and in particular to a boundary control method, device, equipment and storage medium for an orthopedic surgical robot. Background Technology

[0002] Hip replacement surgery involves replacing diseased bone in the hip joint with an artificial prosthesis to restore and improve hip joint function. Hip replacement surgery is necessary when there is severe damage to the hip joint.

[0003] In hip replacement surgery, the two steps of grinding the acetabulum and inserting the acetabular cup are crucial. Grinding the acetabulum to achieve the appropriate position, abduction angle, anteversion angle, and conjoint anteversion angle can prevent dislocation of the placed joint prosthesis and extend its lifespan. Inserting the acetabular cup into the correct position is a prerequisite for good stability and a correct center of rotation of the prosthesis. Because grinding and insertion involve significant reaction forces, hip replacement surgery can place a considerable burden on the surgeon. Therefore, robot-assisted hip replacement surgery can be used to reduce the physical exertion on the surgeon.

[0004] However, when using robots to assist doctors in hip replacement surgery, the acetabular file is prone to excessive movement during the acetabular grinding process, leading to problems such as over-grinding of the acetabulum and reduced surgical precision. Summary of the Invention

[0005] This application provides a robot boundary control method, device, equipment, and storage medium to solve the problem that the acetabular file tends to move too much during robot-assisted acetabular grinding, resulting in excessive grinding of the acetabulum and reduced surgical precision.

[0006] In a first aspect, this application provides a boundary control method for an orthopedic surgical robot, applied to the robot, the robot including surgical tools, the method comprising:

[0007] Obtain the current pose of the end of the surgical tool, and the desired pose that the end of the surgical tool is expected to reach in the next moment;

[0008] Obtain the current baseline position of the patient's acetabulum;

[0009] Based on the current pose, the desired pose, and the reference pose, determine the safe pose of the surgical tool's end effector at the next moment;

[0010] The movement of the surgical tool is controlled based on the current pose and the safe pose.

[0011] In one possible implementation, determining the safe pose of the surgical tool's end effector at the next moment based on the current pose, the desired pose, and the reference pose includes:

[0012] Based on the current position of the tip of the surgical tool, the desired position of the tip of the surgical tool, and the reference point position, determine the safe position of the tip of the surgical tool at the next moment. The distance between the safe position and the reference point position must be less than or equal to a first preset value.

[0013] Based on the current posture of the end of the surgical tool, the desired posture of the end of the surgical tool, and the reference posture, the safe posture of the end of the surgical tool at the next moment is determined, and the vector angle between the unit vector corresponding to the safe posture and the unit vector corresponding to the reference posture must be less than or equal to a second preset value.

[0014] Wherein, the current pose includes the current position and the current posture; the desired pose includes the desired position and the desired posture; the reference pose includes the reference point position and the reference posture; and the safe pose includes the safe position and the safe posture.

[0015] In one possible implementation, determining the safe position of the tip of the surgical tool at the next moment based on the current position of the tip, the desired position of the tip, and the reference point position includes:

[0016] Obtain a first distance between the desired location and the reference point location, and a second distance between the current location and the reference point location;

[0017] The safe location is determined based on the first distance, the second distance, the current location, the desired location, and the reference point location.

[0018] In one possible implementation, the safe location satisfies:

[0019]

[0020] For the aforementioned safe location, For the desired position, The current position, R is the location of the reference point. p The first preset value;

[0021] The first parameter is k1, the second parameter is k2, and the third parameter is k3, and the following conditions must be met:

[0022] In one possible implementation, determining the safe position of the surgical tool's tip at the next moment based on the current position of the surgical tool's tip, the desired position of the surgical tool's tip, and a reference position includes:

[0023] Obtain the first vector angle between the unit vector corresponding to the desired pose and the unit vector corresponding to the reference pose, and the second vector angle between the unit vector corresponding to the current pose and the unit vector corresponding to the reference pose;

[0024] The safe attitude is determined based on the angle between the first vector, the angle between the second vector, the current attitude, the desired attitude, and the reference attitude.

[0025] In one possible implementation, the safety posture satisfies:

[0026]

[0027] in, For the safe posture, R t+Δt For the desired pose, R t For the current posture, A m Let A be the angle between the first vectors. n Let A be the angle between the second vectors. α The second preset value;

[0028]

[0029] Where, A2 = A α -A m I is a unit vector. Angle A is the angle between the first vectors. m Normalized rotation axis vector, for The antisymmetric matrix;

[0030] Where, A1=A α -A n , Angle A is the angle between the second vectors. n Normalized rotation axis vector, for An antisymmetric matrix.

[0031] Secondly, this application provides a boundary control device for an orthopedic surgical robot, comprising:

[0032] The first acquisition module is used to acquire the current pose of the end effector of the surgical tool on the robot, and the expected pose that the end effector of the surgical tool is expected to reach in the next moment.

[0033] The second acquisition module is used to acquire the current reference pose of the patient's acetabulum;

[0034] The processing module is used to determine the safe pose of the end effector of the surgical tool at the next moment based on the current pose, the desired pose, and the reference pose.

[0035] The control module is used to control the movement of the surgical tool according to the current pose and the safe pose.

[0036] In one possible implementation, the processing module is specifically used for:

[0037] Based on the current position of the tip of the surgical tool, the desired position of the tip of the surgical tool, and the reference point position, determine the safe position of the tip of the surgical tool at the next moment. The distance between the safe position and the reference point position must be less than or equal to a first preset value.

[0038] Based on the current posture of the end of the surgical tool, the desired posture of the end of the surgical tool, and the reference posture, the safe posture of the end of the surgical tool at the next moment is determined, and the vector angle between the unit vector corresponding to the safe posture and the unit vector corresponding to the reference posture must be less than or equal to a second preset value.

[0039] Wherein, the current pose includes the current position and the current posture; the desired pose includes the desired position and the desired posture; the reference pose includes the reference point position and the reference posture; and the safe pose includes the safe position and the safe posture.

[0040] In one possible implementation, the processing module is specifically used for:

[0041] Obtain a first distance between the desired location and the reference point location, and a second distance between the current location and the reference point location;

[0042] The safe location is determined based on the first distance, the second distance, the current location, the desired location, and the reference point location.

[0043] In one possible implementation, the safe location satisfies:

[0044]

[0045] For the aforementioned safe location, For the desired position, The current position, R is the location of the reference point.p The first preset value;

[0046] The first parameter is k1, the second parameter is k2, and the third parameter is k3, and the following conditions must be met:

[0047] In one possible implementation, the processing module is specifically used for:

[0048] Obtain the first vector angle between the unit vector corresponding to the desired pose and the unit vector corresponding to the reference pose, and the second vector angle between the unit vector corresponding to the current pose and the unit vector corresponding to the reference pose;

[0049] The safe attitude is determined based on the angle between the first vector, the angle between the second vector, the current attitude, the desired attitude, and the reference attitude.

[0050] In one possible implementation, the safety posture satisfies:

[0051]

[0052] in, For the safe posture, R t+Δt For the desired pose, R t For the current posture, A m Let A be the angle between the first vectors. n Let A be the angle between the second vectors. α The second preset value;

[0053]

[0054] Where, A2 = A α -A m I is a unit vector. Angle A is the angle between the first vectors. m Normalized rotation axis vector, for The antisymmetric matrix;

[0055] Where, A1=A α -A n , Angle A is the angle between the second vectors. n Normalized rotation axis vector, for An antisymmetric matrix.

[0056] Thirdly, this application provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the boundary control method for an orthopedic surgical robot as described in any of the first aspects.

[0057] Fourthly, this application provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the boundary control method for an orthopedic surgical robot as described in any of the first aspects.

[0058] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the boundary control method for an orthopedic surgical robot as described in any of the first aspects.

[0059] The boundary control method, apparatus, device, and storage medium for orthopedic surgical robots provided in this application first acquire the current pose of the end effector of a surgical tool on the robot, and the desired pose that the end effector is expected to reach in the next moment. Then, the current reference pose of the patient's acetabulum is acquired. Based on the current pose, desired pose, and reference pose, the safe pose of the end effector in the next moment is determined. The desired pose is the pose that the end effector of the surgical tool is expected to reach in the next moment. To address the problem that the desired pose might lead to an excessively large range of motion of the tool, resulting in over-grinding of the acetabulum and reduced surgical accuracy, after obtaining the desired pose, the safe pose for the next moment is calculated based on the desired pose, enabling the robotic arm to control the tool to move to the safe pose. By calculating the safe pose and controlling the movement of the surgical tool based on the current pose and the safe pose, the range of motion of the tool is controlled within a boundary range, preventing excessive movement and thus solving the problem of reduced surgical accuracy caused by over-grinding of the acetabulum. Attached Figure Description

[0060] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0061] Figure 1 This is a schematic diagram of an application scenario provided by an embodiment of this application;

[0062] Figure 2 A flowchart illustrating the boundary control method for an orthopedic surgical robot provided in an embodiment of this application;

[0063] Figure 3A boundary control schematic diagram provided for an embodiment of this application;

[0064] Figure 4 A flowchart illustrating the process of determining a safe pose provided in an embodiment of this application;

[0065] Figure 5 A schematic diagram illustrating the determination of a safe location as provided in an embodiment of this application;

[0066] Figure 6 A schematic diagram illustrating the determination of a safe posture as provided in an embodiment of this application;

[0067] Figure 7 A schematic diagram of the boundary control device for an orthopedic surgical robot provided in an embodiment of this application;

[0068] Figure 8 This is a schematic diagram of the physical structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0070] The human hip joint, composed of the femoral head and acetabulum, connects the femur to the pelvis and is one of the most stress-bearing joints in the body. When hip joint diseases such as severe osteoarthritis, rheumatoid arthritis, or traumatic arthritis occur, the hip joint cannot perform its normal function, requiring hip replacement surgery. This involves replacing the diseased bone with an artificial prosthesis (comprising the femoral and acetabular portions) to relieve joint pain, correct deformities, restore and improve joint function, and enhance the patient's quality of life.

[0071] The steps of hip replacement surgery typically include patient positioning, skin incision to expose the hip joint, protruding the femoral head from the acetabulum, femoral neck osteotomy, exposure of the acetabulum, removal of osteophytes around the acetabulum, grinding the acetabulum with an acetabular reamer, insertion of the acetabular cup, implantation of the acetabular liner, preparation of the femoral medullary cavity, implantation of the femoral prosthesis, installation of the femoral head prosthesis, adjustment, and suturing. Among these steps, grinding the acetabulum and inserting the acetabular cup require relatively high levels of surgical skill. Grinding the acetabulum to achieve the appropriate position, abduction angle, anteversion angle, and conjoint anteversion angle can prevent dislocation of the implanted joint prosthesis and extend its lifespan; inserting the acetabular cup in the correct position is a prerequisite for good stability and a correct center of rotation of the prosthesis. These two crucial steps directly affect the success or failure of the entire hip replacement surgery.

[0072] In traditional hip replacement surgery, the acetabulum is ground down manually by the surgeon using a handheld acetabular file, and the acetabular cup is inserted by the surgeon using a handheld inserter and a bone hammer. On the one hand, manual operation reduces the precision of grinding and insertion, thus lowering the overall surgical outcome; on the other hand, the significant reaction forces from grinding and insertion also place a considerable burden on the surgeon. Therefore, robot-assisted hip replacement surgery is gradually becoming more widely used.

[0073] Robot-assisted hip replacement surgery allows for interactive acetabular grinding with the assistance of a robotic arm. The robotic arm holds the inserter, while the surgeon inserts the acetabular cup. This improves the precision of both the grinding and cup insertion, enhancing surgical outcomes while significantly reducing the surgeon's physical exertion. For example, it can be combined with… Figure 1 This article introduces robot-assisted hip replacement surgery.

[0074] Figure 1 This is a schematic diagram of an application scenario provided in an embodiment of this application, such as... Figure 1 As shown, in robot-assisted hip replacement surgery, there are a patient, a doctor, and a surgical robot 10, each located in a different position.

[0075] The surgical robot 10 includes a motion control device 11, a robotic arm 12, a six-dimensional force sensor 13, surgical instruments 14, and an optical positioning sensor 15. The motion control device 11 may include an incremental control module, an admittance controller, a boundary control module, a six-dimensional force transformation module, a dead-zone controller, and a low-pass filter, etc. The motion control device 11 and the robotic arm 12, the motion control device 11 and the six-dimensional force sensor 13, and the motion control device 11 and the optical positioning sensor 15 can all be connected via a communication bus for data communication.

[0076] The incremental control module can be used by doctors to control surgical tools for rapid and accurate tracking when the patient's limb moves during acetabular grinding and acetabular cup insertion. Specifically, based on preoperative planning software, the target pose deviation between the patient's lesion and the surgical tool can be calculated. This target pose deviation is the ideal deviation between the pose of the patient's lesion and the pose of the surgical tool during surgery. The optical positioning sensor 15 can be used to acquire the current pose deviation between the patient's lesion and the surgical tool 14. Then, by comparing the target pose deviation and the current pose deviation, the incremental control module generates the command speed of the surgical tool 14. This speed is then superimposed with the current pose of the surgical tool 14 fed back by the robotic arm 12 to generate the desired pose, enabling the robotic arm 12 to control the surgical tool 14 for rapid and accurate tracking.

[0077] The raw six-dimensional force information collected by the six-dimensional force sensor 13 is transformed into six-dimensional force information at the end of the surgical tool 14 after six-dimensional force transformation (completed by the six-dimensional force transformation module), dead zone control (completed by the dead zone controller), and low-pass filtering (completed by the low-pass filter). The admittance controller generates the compliant posture of the surgical tool 14 as desired by the surgeon based on the current pose and velocity of the surgical tool 14 fed back by the robotic arm 12, and the transformed six-dimensional force information at the end of the surgical tool 14. This compliant posture can be sent to the robotic arm 12 to move the surgical tool 14, thereby precisely achieving dynamic grinding or insertion holding of the acetabulum.

[0078] During the acetabular grinding process in hip replacement surgery using a robotic system, the acetabular file is prone to excessive range of motion, leading to problems such as over-grinding of the acetabulum and reduced surgical precision. Therefore, this application provides a robot boundary control method to limit the position and posture of the acetabular file to prevent over-grinding of the acetabulum due to excessive range of motion. Under the premise of easy control, precision and safety, this method meets the actual technical requirements of robot-assisted hip replacement surgery.

[0079] based on Figure 1 Example application scenarios, combined with the following Figure 2 The solutions of the embodiments of this application will be described. Figure 2 This is a flowchart illustrating the boundary control method for an orthopedic surgical robot provided in an embodiment of this application, as shown below. Figure 2 As shown, the method may include:

[0080] S21, obtain the current pose of the end effector of the surgical instrument, and the desired pose that the end effector of the surgical instrument is expected to reach in the next moment.

[0081] The execution subject of this application embodiment can be a robot, which includes surgical tools, such as surgical tools used in hip replacement surgery. The surgical tools can be connected to a robotic arm and move under the control of the robotic arm. Figure 3 A boundary control schematic diagram provided for an embodiment of this application, such as... Figure 3 As shown, taking an acetabular reamer as an example, the surgical tool may include an acetabular cup 31 and a reamer handle 32.

[0082] At the current moment, the current pose of the surgical tool's end effector can be obtained. The pose can include both position and orientation; therefore, the current pose includes the current position and orientation of the surgical tool's end effector. Furthermore, the desired pose of the surgical tool's end effector can also be obtained. The desired pose is the pose the surgical tool's end effector is expected to reach at the next moment. The desired pose can also include the desired position and orientation. When the surgical tool is selected as an acetabular grinder, and the end effector corresponds to the center O of the acetabular cup, then the current position and desired position are the current position and desired position of the center O of the acetabular cup, and the current orientation and desired orientation are the orientation of the grinder handle 32.

[0083] S22, obtain the current reference position of the patient's acetabulum.

[0084] The patient's current acetabular reference pose can include a reference point position and a reference orientation. The reference point position can be the acetabular center, and the reference orientation is the spherical normal orientation passing through the acetabular center. The above design is not the only possible design for the patient's current acetabular reference pose and may need to be set according to actual conditions. The patient's acetabular reference pose is also updated and tracked in real time by the optical positioning sensor 15 (NDI camera). When the patient moves, because the patient is equipped with a tracer, their pose is tracked and updated in real time by the optical positioning sensor 15 (NDI camera). Therefore, when implementing this method, the real-time updated current reference pose needs to be used for boundary control.

[0085] S23, determine the safe position of the surgical instrument's end effector at the next moment based on the current pose, the desired pose, and the reference pose.

[0086] The current pose refers to the position and orientation of the surgical instrument's end effector at the current moment, while the desired pose is the position and orientation the end effector is expected to reach in the next moment. Without boundary control, the robotic arm controls the instrument to move towards the desired pose, ensuring the end effector reaches that pose in the next moment. However, due to the possibility of excessive movement, boundary control is necessary, and this boundary control is related to the reference pose. Based on the reference pose, a preset range can be set to determine the safe pose of the surgical instrument's end effector in the next moment, considering the current pose, desired pose, and reference pose.

[0087] It should be noted that since pose includes position and orientation, there are corresponding boundary control ranges for position and orientation respectively. Safe pose includes safe position and safe orientation, and reference pose includes reference point position and reference orientation. Therefore, the safe pose obtained according to this scheme satisfies the following: the distance between the safe position and the reference point position is less than or equal to a first preset value, and the vector angle between the unit vector corresponding to the safe orientation and the unit vector corresponding to the reference orientation is less than or equal to a second preset value.

[0088] For example, the desired pose includes both the desired position and the desired orientation. When the distance between the desired position and the reference point is less than or equal to a first preset value, and the angle between the unit vector corresponding to the desired orientation and the unit vector corresponding to the reference orientation is less than or equal to a second preset value, it indicates that the range of motion is not large, and the desired pose can be directly determined as the safe pose. Otherwise, the safe pose needs to be determined based on the current pose, the desired pose, and the reference pose. Regardless of which situation occurs after the judgment, the final determined safe pose must satisfy: the distance between the safe position and the reference point is less than or equal to the first preset value, and the angle between the unit vector corresponding to the safe orientation and the unit vector corresponding to the reference orientation is less than or equal to the second preset value.

[0089] S24 controls the movement of surgical instruments based on the current pose and safe pose.

[0090] Once a safe position is determined, the surgical instruments can be controlled to move from the current position to the safe position based on the deviation between the current position and the safe position.

[0091] The orthopedic surgical robot boundary control method provided in this application is applied to a robot. First, it acquires the current pose and desired pose of the end effector of a surgical tool on the robot. Then, it acquires the current reference pose of the patient's acetabulum. Based on the current pose, desired pose, and reference pose, it determines the safe pose of the end effector at the next moment. The desired pose is the pose the end effector of the surgical tool is expected to reach at the next moment. To address the issue that an excessively large desired pose might lead to over-grinding of the acetabulum and reduced surgical precision, the safe pose for the next moment is calculated based on the desired pose after obtaining it. This allows the robotic arm to control the tool to move to the safe pose. By calculating the safe pose and controlling the movement of the surgical tool based on the current pose and the safe pose, the tool's movement range is controlled within a boundary range, preventing excessive movement and thus solving the problem of reduced surgical precision caused by over-grinding of the acetabulum.

[0092] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0093] To address the shortcomings of manual hip replacement surgery and the limitations of robotic arms in existing robot-assisted hip replacement surgery, this application proposes a boundary control method for a hip replacement surgery robot. This method can precisely and easily assist surgeons in performing acetabular grinding during hip replacement surgery, while ensuring the safety of the grinding boundary, thereby improving the success rate of hip replacement surgery and reducing the burden on surgeons.

[0094] Specifically, based on the current pose and speed of the surgical tool fed back by the robotic arm, as well as the surgeon's desired compliant pose, a safe and compliant pose for the surgical tool can be calculated and sent to the robotic arm to move the tool, thereby achieving precise and safe dynamic grinding or insertion holding of the acetabulum. The pose refers to both position and orientation in Cartesian space. In the calculation of the safe and compliant pose, the position constraint is a spherical constraint, and the orientation constraint is a conical constraint along any specified axis (X-axis, Y-axis, or Z-axis).

[0095] Figure 4 This is a flowchart illustrating the process of determining a safe pose provided in an embodiment of this application, as shown below. Figure 4 As shown, it includes:

[0096] S41, determine the safe position of the end of the surgical instrument at the next moment based on the current position of the end of the surgical instrument, the desired position of the end of the surgical instrument, and the position of the reference point.

[0097] In this embodiment of the application, the current pose includes the current position and the current attitude; the desired pose includes the desired position and the desired attitude; the reference pose includes the reference point position and the reference attitude; and the safe pose includes the safe position and the safe attitude.

[0098] In this embodiment, the position boundary control is a spherical constraint control, where the center of the sphere is the reference point position, and the range of motion of the end of the surgical tool is controlled within a sphere with the reference point position as the center and a first preset value as the radius.

[0099] First, obtain the first distance between the desired location and the reference point location, and the second distance between the current location and the reference point location. Then, based on the first distance, the second distance, the current location, the desired location, and the reference point location, determine the safe location. The distance between the desired location and the reference point location has two possible relationships: either the distance is less than or equal to a first preset value, or it is greater than the first preset value.

[0100] When the distance between the desired position and the reference point is less than or equal to the first preset value, it means that the desired position is within the sphere centered on the reference point and with the first preset value as its radius. In this case, no adjustment is needed, and the desired position can be directly determined as the safe position. When the distance between the desired position and the reference point is greater than the first preset value, it means that the desired position has exceeded the sphere centered on the reference point and with the first preset value as its radius. In this case, the desired position needs to be adjusted to ultimately determine the safe position, ensuring that the safe position lies within the sphere centered on the reference point and with the first preset value as its radius, thereby achieving boundary control of the position.

[0101] Figure 5This is a schematic diagram illustrating the determination of a safe location provided in an embodiment of this application, such as... Figure 5 As shown, the position boundary control mainly adopts boundary control based on spherical boundary judgment. Let the coordinates of the reference point of the end position boundary of the surgical tool be... (The coordinates of the reference point are) (That is, the reference point position), the radius of the boundary sphere is R. p (R p That is, the first preset value; the boundary sphere is a sphere with the reference point as its center and the first preset value as its radius. The current position of the end of the surgical instrument at time t (i.e., the current time) is... The desired position of the surgical instrument's tip at time t+Δt (i.e., the next time step) is:

[0102] Without position boundary control, the robot will control the end effector of the surgical instrument to move to the desired position in the next moment. In this embodiment, since position boundary control is required, it is necessary to determine the desired position. Whether it is inside the boundary sphere requires further processing.

[0103] Specifically, the safe position of the tip of the surgical instrument at time t+Δt. The following formula (1) can be used for calculation:

[0104]

[0105] For a safe location, For the desired position, Current position R is the reference point position. p This is the first preset value.

[0106] Where k1 is the first parameter, k2 is the second parameter, and k3 is the third parameter, and satisfies:

[0107]

[0108]

[0109]

[0110] As shown in formula (1), when "Time" indicates the current position. Located outside the boundary sphere, this is the safe position. when and "Time" indicates the current position. Desired position within the boundary sphere If the object is also located within the boundary sphere (including on the surface of the boundary sphere), then the safe position is the desired position. when and "Time" indicates the current position. Desired position within the boundary sphere Being outside the boundary sphere, it is necessary to determine the current position. Desired location Reference point location and the first preset value R p Determine a safe location, where the safe location is... Located on the surface of the boundary sphere, this is the current position. and desired location The intersection of the line connecting the two points and the surface of the boundary sphere.

[0111] when and At that time, safe position The calculation formula can be obtained from the following process. Due to the safe location... Located on the surface of the boundary sphere, this is the current position. and desired location The intersection of the line connecting the two points with the surface of the boundary sphere is given by the two-point form of the straight line equation:

[0112]

[0113] Where k is the slope of the two-point equation of a straight line. Due to the location of the reference point... Get to a safe location The distance is equal to the first preset value R p (i.e., the radius of the boundary sphere), therefore:

[0114]

[0115] Substituting equation (2) into equation (3), we get:

[0116]

[0117] Equivalent to:

[0118]

[0119]

[0120] set up:

[0121]

[0122] Then we have:

[0123] k1*k 2+2*k2*k+k3=0,

[0124] Solving the equation, we get:

[0125]

[0126] And due to the current location Located inside the boundary sphere, desired location Located outside the boundary sphere, combined with equation (2), we know that k∈[0,1], therefore we can obtain:

[0127]

[0128] Through the aforementioned position boundary control, it can be ensured that when the surgeon's desired compliant position of the surgical instrument exceeds the spherical boundary, the position will be corrected to be within the spherical boundary. With R as the center of the ball p Within a sphere of radius , the position conforming to the desired direction.

[0129] S42, determine the safe position of the surgical instrument's end point at the next moment based on the current position of the surgical instrument's end point, the desired position of the surgical instrument's end point, and the reference position.

[0130] In this embodiment, attitude boundary control is a conical constraint control along an arbitrary specified axis. First, based on the desired attitude, the reference point attitude, and the reference point attitude, the first vector angle between the unit vector corresponding to the desired attitude and the unit vector corresponding to the reference attitude, and the second vector angle between the unit vector corresponding to the current attitude and the unit vector corresponding to the reference attitude, are obtained. Then, based on the first vector angle, the second vector angle, the current attitude, the desired attitude, and the reference attitude, the safe attitude is determined. The following is combined with... Figure 6 This process will be described.

[0131] Figure 6 This is a schematic diagram illustrating the determination of a safe posture provided in an embodiment of this application, such as... Figure 6 As shown, attitude boundary control mainly adopts boundary control based on cone boundary judgment. The Cartesian space attitude is represented by a rotation matrix, and the end effector of the surgical tool is in the boundary reference attitude R. o The corresponding unit vector of the coordinate axis is The semi-apex angle of the cone-shaped boundary of the end face of the surgical tool is A. α At time t, the current pose of the surgical instrument's end effector is R. t The corresponding unit vector of the coordinate axis is The desired end effector orientation of the surgical instrument at time t+Δt (planned) is R. t+Δt The corresponding unit vector of the coordinate axis is Then the safe end position of the surgical instrument at time t+Δt It can be calculated in the following way.

[0132] by The axis is a conical reference axis. Since the coordinate axis vectors are all unit vectors, let:

[0133]

[0134] The first vector angle A between the unit vector corresponding to the desired attitude and the unit vector corresponding to the reference attitude can be obtained. m And the angle A between the second vectors of the unit vector corresponding to the current attitude and the unit vector corresponding to the reference attitude. n :

[0135]

[0136] Normalized rotation axis vector It can be represented as:

[0137]

[0138] Prioritizes the desired end-effector pose R at time t (current). t corresponding With boundary reference attitude R o corresponding The angle A between the second vectors n It has exceeded A α At that time, it is necessary to put R t Around Axis rotation A1 = A α -A n Angle, to limit it.

[0139] The desired end-effector posture R at time t+Δt (planned) t+Δt corresponding With boundary reference attitude R o corresponding The angle A between the second vectors m More than A α At that time, it is necessary to put R t+Δt Around Axis rotation A2 = (A α -A m Angles are used to limit it. Then the formula is: The safe posture satisfies:

[0140]

[0141] in, For a safe posture, R t For the current posture, R t+Δt For the desired posture, Am and A n Let A be the angle between the vectors. α The second preset value;

[0142]

[0143] Where, A1=A α -A n I is a unit vector. Angle A between the vectors n Normalized rotation axis vector, for An antisymmetric matrix.

[0144]

[0145] Where, A2 = A α -A m I is a unit vector. Angle A between the vectors m Normalized rotation axis vector, for An antisymmetric matrix.

[0146] by axis, The derivation of the formula for the axis being the conical reference axis is similar and will not be repeated here.

[0147] Through the above-described posture boundary control, it can be ensured that the surgical instrument is in a compliant position according to the specified axis (as desired by the surgeon). axis, shaft or When the axis exceeds the conical boundary, the attitude is corrected to be at R o The specified axis ( axis, shaft or (axis) as the axis, with A α Within the cone-shaped area of ​​the semi-apex angle, the posture conforms to the desired direction.

[0148] Based on the above method, during the doctor's operation, a compliant movement can be generated, provided that the position and posture boundaries are not exceeded, to adapt to the doctor's operation.

[0149] In summary, the solution of this application embodiment, through position boundary control, ensures that when the position of the surgical tool's desired compliant posture exceeds the spherical boundary, the position is corrected to within a spherical range of a specified radius and conforms to the desired direction. Through posture boundary control, it ensures that when the specified axis of the surgical tool's desired compliant posture exceeds the conical boundary, the posture is corrected to within a conical range of a specified semi-apex angle and conforms to the desired direction. During the process of grinding the patient's acetabulum, when the doctor needs to dynamically adjust the posture of the acetabular file, the robotic arm can limit the safe area for the doctor's dynamic adjustment, ensuring the safety of acetabular grinding. Furthermore, since this solution directly controls the position and posture boundaries, compared to controlling force and then converting it into motion commands, the process of converting force commands into motion commands has a certain time lag, resulting in some residual motion command components after the force is limited to zero. These residual components need secondary processing to ensure the limiting effect. This solution directly controls the motion command components without secondary processing, resulting in a better limiting effect.

[0150] The robot boundary control device provided in this application is described below. The robot boundary control device described below can be referred to in correspondence with the robot boundary control method described above.

[0151] Figure 7 This is a schematic diagram of the boundary control device for an orthopedic surgical robot provided in an embodiment of this application, as shown below. Figure 7 As shown, the device includes:

[0152] The first acquisition module 71 is used to acquire the current pose of the end of the surgical tool and the expected pose that the end of the surgical tool is expected to reach in the next moment.

[0153] The second acquisition module 72 is used to acquire the current reference pose of the patient's acetabulum;

[0154] Processing module 73 is used to determine the safe pose of the end of the surgical tool at the next moment based on the current pose, the desired pose, and the reference pose;

[0155] The control module 74 is used to control the movement of the surgical tool according to the current pose and the safe pose.

[0156] In one possible implementation, the processing module 73 is specifically used for:

[0157] Based on the current position of the tip of the surgical tool, the desired position of the tip of the surgical tool, and the reference point position, determine the safe position of the tip of the surgical tool at the next moment. The distance between the safe position and the reference point position must be less than or equal to a first preset value.

[0158] Based on the current posture of the end of the surgical tool, the desired posture of the end of the surgical tool, and the reference posture, the safe posture of the end of the surgical tool at the next moment is determined, and the vector angle between the unit vector corresponding to the safe posture and the unit vector corresponding to the reference posture must be less than or equal to a second preset value.

[0159] Wherein, the current pose includes the current position and the current posture; the desired pose includes the desired position and the desired posture; the reference pose includes the reference point position and the reference posture; and the safe pose includes the safe position and the safe posture.

[0160] In one possible implementation, the processing module 73 is specifically used for:

[0161] Obtain a first distance between the desired location and the reference point location, and a second distance between the current location and the reference point location;

[0162] The safe location is determined based on the first distance, the second distance, the current location, the desired location, and the reference point location.

[0163] In one possible implementation, the safe location satisfies:

[0164]

[0165] For the aforementioned safe location, For the desired position, The current position, R is the location of the reference point. p The first preset value;

[0166] The first parameter is k1, the second parameter is k2, and the third parameter is k3, and the following conditions must be met:

[0167] In one possible implementation, the processing module 73 is specifically used for:

[0168] Obtain the first vector angle between the unit vector corresponding to the desired pose and the unit vector corresponding to the reference pose, and the second vector angle between the unit vector corresponding to the current pose and the unit vector corresponding to the reference pose;

[0169] The safe attitude is determined based on the angle between the first vector, the angle between the second vector, the current attitude, the desired attitude, and the reference attitude.

[0170] In one possible implementation, the safety posture satisfies:

[0171]

[0172] in, For the safe posture, R t+Δt For the desired pose, R t For the current posture, A m Let A be the angle between the first vectors. n Let A be the angle between the second vectors. α The second preset value;

[0173]

[0174] Where, A2 = A α -A m I is a unit vector. Angle A is the angle between the first vectors. m Normalized rotation axis vector, for The antisymmetric matrix;

[0175] Where, A1=A α -A n , Angle A is the angle between the second vectors. n Normalized rotation axis vector, for An antisymmetric matrix.

[0176] The boundary control device for the orthopedic surgical robot provided in this application embodiment is used to execute the above method embodiment. Its implementation principle and technical effect are similar, and will not be described again here.

[0177] Figure 8 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 8As shown, the electronic device may include a processor 810, a communications interface 820, a memory 830, and a communication bus 840, wherein the processor 810, communications interface 820, and memory 830 communicate with each other via the communication bus 840. The processor 810 can call logical instructions in the memory 830 to execute a boundary control method for an orthopedic surgical robot. This method includes: acquiring the current pose of the end effector of a surgical tool and the desired pose that the end effector of the surgical tool is expected to reach at the next moment; acquiring the current reference pose of the patient's acetabulum; determining the safe pose of the end effector of the surgical tool at the next moment based on the current pose, the desired pose, and the reference pose; and controlling the movement of the surgical tool based on the current pose and the safe pose.

[0178] Furthermore, the logical instructions in the aforementioned memory 830 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the 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 cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0179] On the other hand, this application also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to execute the boundary control method for the orthopedic surgical robot provided by the above methods. The method includes: acquiring the current pose of the end effector of a surgical tool and the desired pose that the end effector of the surgical tool is expected to reach at the next moment; acquiring the current reference pose of the patient's acetabulum; determining the safe pose of the end effector of the surgical tool at the next moment based on the current pose, the desired pose, and the reference pose; and controlling the movement of the surgical tool based on the current pose and the safe pose.

[0180] In another aspect, this application also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements a boundary control method for an orthopedic surgical robot provided by the methods described above. The method includes: acquiring the current pose of the end effector of a surgical tool and the desired pose the end effector of the surgical tool is expected to reach at the next moment; acquiring the current reference pose of the patient's acetabulum; determining the safe pose of the end effector of the surgical tool at the next moment based on the current pose, the desired pose, and the reference pose; and controlling the movement of the surgical tool based on the current pose and the safe pose.

[0181] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0182] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0183] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A boundary control method for an orthopedic surgical robot, applied to the robot, the robot including surgical tools, characterized in that, The method includes: Obtain the current pose of the end of the surgical tool, and the desired pose that the end of the surgical tool is expected to reach in the next moment; Obtain the current baseline position of the patient's acetabulum; Based on the current pose, the desired pose, and the reference pose, determine the safe pose of the surgical tool's end effector at the next moment; The movement of the surgical tool is controlled according to the current pose and the safe pose; Determining the safe pose of the surgical tool's end effector at the next moment based on the current pose, the desired pose, and the reference pose includes: Based on the current pose of the surgical tool's end effector, the desired pose of the surgical tool's end effector, and the reference pose, the safe pose of the surgical tool's end effector at the next moment is determined. The vector angle between the unit vector corresponding to the safe pose and the unit vector corresponding to the reference pose must be less than or equal to a second preset value. The current pose includes the current position and the current pose; the desired pose includes the desired position and the desired pose; the reference pose includes the reference point position and the reference pose; and the safe pose includes the safe position and the safe pose. The step of determining the safe posture of the surgical tool's end effector at the next moment based on the current posture of the end effector, the desired posture of the end effector, and the reference posture includes: obtaining a first vector angle between the unit vector corresponding to the desired posture and the unit vector corresponding to the reference posture, and a second vector angle between the unit vector corresponding to the current posture and the unit vector corresponding to the reference posture; determining the safe posture based on the first vector angle, the second vector angle, the current posture, the desired posture, and the reference posture; the safe posture satisfies: ； in, For the aforementioned safe posture, For the desired posture, The current posture, The angle between the first vectors, The angle between the second vectors, The second preset value; ， ， in, , It is a unit vector. The angle between the first vectors Normalized rotation axis vector, for The antisymmetric matrix; in, , The angle between the second vectors Normalized rotation axis vector, for An antisymmetric matrix.

2. The boundary control method for the orthopedic surgical robot according to claim 1, characterized in that, The step of determining the safe pose of the surgical tool's end effector at the next moment based on the current pose, the desired pose, and the reference pose further includes: Based on the current position of the tip of the surgical tool, the desired position of the tip of the surgical tool, and the position of the reference point, the safe position of the tip of the surgical tool at the next moment is determined, and the distance between the safe position and the reference point position must be less than or equal to a first preset value.

3. The boundary control method for the orthopedic surgical robot according to claim 2, characterized in that, Determining the safe position of the tip of the surgical tool at the next moment based on the current position of the tip, the desired position of the tip, and the reference point position includes: Obtain a first distance between the desired location and the reference point location, and a second distance between the current location and the reference point location; The safe location is determined based on the first distance, the second distance, the current location, the desired location, and the reference point location.

4. The boundary control method for the orthopedic surgical robot according to claim 3, characterized in that, The safe location satisfies: ； For the aforementioned safe location, For the desired position, The current position, The reference point position is... The first preset value; The As the first parameter, the As the second parameter, the It is the third parameter, and satisfies , , .

5. A boundary control device for an orthopedic surgical robot, characterized in that, include: The first acquisition module is used to acquire the current pose of the end effector of the surgical tool on the robot, and the expected pose that the end effector of the surgical tool is expected to reach in the next moment. The second acquisition module is used to acquire the current reference pose of the patient's acetabulum; The processing module is used to determine the safe pose of the end effector of the surgical tool at the next moment based on the current pose, the desired pose, and the reference pose. The control module is used to control the movement of the surgical tool according to the current pose and the safe pose; The processing module is specifically configured to determine the safe posture of the surgical tool's end effector at the next moment based on the current posture of the end effector, the desired posture of the end effector, and the reference posture. The vector angle between the unit vector corresponding to the safe posture and the unit vector corresponding to the reference posture must be less than or equal to a second preset value. The current posture includes the current position and the current posture; the desired posture includes the desired position and the desired posture; the reference posture includes the reference point position and the reference posture; and the safe posture includes the safe position and the safe posture. The processing module is specifically used to obtain a first vector angle between the unit vector corresponding to the desired pose and the unit vector corresponding to the reference pose, and a second vector angle between the unit vector corresponding to the current pose and the unit vector corresponding to the reference pose; and to determine the safe pose based on the first vector angle, the second vector angle, the current pose, the desired pose, and the reference pose; the safe pose satisfies: ； in, For the aforementioned safe posture, For the desired posture, The current posture, The angle between the first vectors, The angle between the second vectors, The second preset value; ， ， in, , It is a unit vector. The angle between the first vectors Normalized rotation axis vector, for The antisymmetric matrix; in, , The angle between the second vectors Normalized rotation axis vector, for An antisymmetric matrix.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the boundary control method for the orthopedic surgical robot as described in any one of claims 1-4.

7. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the boundary control method for the orthopedic surgical robot as described in any one of claims 1-4.

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the boundary control method for the orthopedic surgical robot as described in any one of claims 1-4.

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