CN116898573A - Osteotomy plane boundary control method, electronic equipment and storage medium - Google Patents

Abstract

The invention discloses an osteotomy plane boundary control method, electronic equipment and a storage medium, wherein the method comprises the steps of calculating the distance from the central point of an osteotomy pendulum saw to the boundary connecting line of an osteotomy plane, selecting inward vectors of two sides with the shortest distance, weighting and summing the two sides as a searching direction, performing step searching to quickly find a safe position closest to the plane position boundary (namely, conforming to the expected movement direction and gesture) and positioned in the plane boundary, and then issuing the safe position to a mechanical arm to drive a surgical tool to move so as to accurately and safely help doctors to realize osteotomy operation on thighbone and tibia. Solves the technical problem of soft tissue and ligament injury and operation precision reduction caused by overlarge movement range of the osteotomy pendulum saw in the prior art.

Description

Osteotomy plane boundary control method, electronic equipment and storage medium

Technical Field

The invention relates to the technical field of artificial intelligence, in particular to an osteotomy plane boundary control method, electronic equipment and a storage medium.

Background

The knee joint of human body is composed of joint surfaces among femur, tibia and patella, and is a joint for connecting femur and tibia, and is one of joints with highest whole body stress. When a lesion of a knee joint such as severe osteoarthritis, rheumatoid arthritis, traumatic arthritis, etc. occurs, the knee joint fails to function normally, and a knee joint replacement is required, and the diseased portion (including a femoral portion, a tibial portion, a meniscus, etc.) is replaced with an artificial prosthesis to relieve joint pain, correct deformity, restore and improve the motor function of the joint, and improve the quality of life of a patient.

The knee joint surface of a person is covered by cartilage, the cartilage gradually wears with the increase of age, bones and ligaments around the knee joint are degenerated, and finally knee joint pain, deformity and movement disorder are caused. Many people find that knee arthroplasty is a replacement of the entire knee, but not the most so, and knee arthroplasty is a replacement of the cartilage of the surface of the knee, which has been worn into a depression, with a metallic prosthesis and a wear-resistant pad of high molecular polyethylene.

Types of artificial knee replacements include Total Knee Arthroplasty (TKA) and unicondylar arthroplasty (UKA).

Taking Total Knee Arthroplasty (TKA), which refers to the procedure of replacing a knee joint deformed by knee osteoarthritis or rheumatoid arthritis with an artificial material (as shown in fig. 1), is an effective surgical way to treat end-stage knee osteoarthritis caused by various causes.

The steps of knee arthroplasty (TKA) typically include patient positioning, skin incision, knee joint exposure, tibial anterior pull dislocation, soft tissue loosening, removal of surrounding osteophytes, five plane (anterior, distal, posterior condyle) osteotomies of the femur, tibial plane osteotomies, femoral prosthesis installation, tibial prosthesis implantation, tibial insert installation, adjustment and suturing, and the like. In the steps, the technical requirements of the femur and tibia planar osteotomy are relatively high, and the doctor is required to accurately perform osteotomy according to the set position and posture, so that the cut joint section is ensured to conform to the operation planning, and the femoral and tibial planar osteotomy has good flexion-extension clearance balance and recovers accurate lower limb force lines. The perfect osteotomy operation can not only relieve the postoperative pain degree of a patient and improve the knee joint function of the patient, but also prevent dislocation of the laid joint prosthesis and reduce Notching (anterior femoral cortex notch, which is a common postoperative complication of TKA, and refers to the defect of anterior femoral cortex caused by poor anterior condyle osteotomy in TKA operation, and the phenomenon that the vertical distance between the furthest end tangent line of the anterior femoral cortex and the contact tangent line of the femoral prosthesis is more than 1 mm), and the service life of the prosthesis is prolonged. Therefore, the two important links of femur and tibia plane osteotomy are directly related to the success or failure of the whole operation.

In traditional knee joint replacement, planar osteotomies of femur and tibia are manually performed by a doctor holding an osteotomic pendulum saw. On one hand, the manual handheld operation reduces the plane precision of osteotomy, and can damage soft tissues and ligaments of patients, thereby reducing the treatment effect of the whole operation; on the other hand, a large cutting reaction force also places a large burden on the doctor.

Still other methods of ensuring planar osteotomy precision and boundary constraints use osteotomy guides or four-in-one guides that are secured to the femur or tibia with a kirschner wire after the knee joint is exposed, and use a hand-held osteotomy pendulum saw to complete the osteotomy. This approach requires additional nailing of the patient's bone, making the procedure more cumbersome, and in addition, the manually controlled osteotomy pendulum saw by the doctor cannot completely guarantee that the patient's soft tissues and ligaments are not damaged.

The knee joint replacement operation assisted by the robot can assist a doctor to perform interactive femur and tibia plane osteotomy by the mechanical arm, the mechanical arm drives the osteotomy swing saw, and the doctor triggers tool power to controllably complete the osteotomy process. Not only can improve the accuracy of plane osteotomy, but also greatly reduces the physical effort of doctors while improving the operation effect. However, in the femoral and tibial plane osteotomies cutting process using the robot to assist in knee joint replacement operation, the position of the osteotomic pendulum saw in the osteotomic plane needs to be limited by a certain boundary, so that soft tissue and ligament injuries caused by overlarge movement range are prevented from being generated, and the operation precision is reduced. In the prior art, as the osteotomy pendulum saw of the robot cannot be limited in the osteotomy plane, soft tissues and ligaments are damaged and the operation precision is reduced due to the overlarge movement range of the osteotomy pendulum saw.

Disclosure of Invention

The invention aims to overcome the technical defects, and provides an osteotomy plane boundary control method, electronic equipment and a storage medium, so as to solve the technical problems of soft tissue and ligament injury and operation precision reduction caused by overlarge movement range of an osteotomy pendulum saw in the related art.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

according to a first aspect of the present invention, there is provided an osteotomy plane boundary control method, comprising:

step S1, selecting the inward vector weighted summation of two sides with the shortest distance as a searching direction by calculating the distance from the central point of the osteotomy pendulum saw to the boundary connecting line of the osteotomy plane, and performing step-by-step searching;

step S2, after each step search is completed, updating the coordinates of the search points, and determining the coordinates of the left limit point and the coordinates of the right limit point corresponding to the cutting edge surface of the osteotomy pendulum saw according to the updated search coordinate points;

s3, judging whether a connecting line between the left limit point and the right limit point is intersected with a boundary connecting line of the osteotomy plane, if not, completing searching, and outputting the current searching coordinate point as a safety coordinate of a central point of the osteotomy pendulum saw; if yes, returning to the step S1 to recalculate the searching direction and carrying out step-by-step searching.

Preferably, the step S1 includes:

step S11, acquiring planning coordinates of a central point of the osteotomy pendulum saw, a planning direction vector of the osteotomy pendulum saw, a boundary point set of an osteotomy plane, and a boundary line set formed by the boundary point set, wherein the single stepping quantity is obtained;

step S12, traversing each boundary connecting line in the boundary connecting line set, and calculating the distance from the center point of the osteotomy pendulum saw to each boundary connecting line and the coordinate of the nearest point;

step S13, traversing the distance from the center point of the osteotomy pendulum saw to the boundary connecting line, and searching index numbers of two boundary connecting lines with the shortest distance;

step S14, judging whether the center point of the osteotomy pendulum saw is positioned in the boundary connecting line set, if yes, initializing a searching coordinate point to be equal to the planning coordinate of the center point of the osteotomy pendulum saw, otherwise, initializing the searching coordinate point to be equal to the nearest point coordinate on the shortest boundary connecting line;

and S15, calculating a search direction, wherein the search direction is the weighted summation of the direction vectors of the two boundary connecting lines with the shortest distance, and the weight value of the direction vector of each boundary connecting line is the distance value between the other boundary connecting line and the center point of the osteotomy swing saw.

Preferably, the step S2 includes:

step S21, step searching is carried out along the searching direction, and after each step searching is completed, the searching coordinate point is updated to be the sum of the original searching coordinate point and the step amount in the searching direction;

And S22, calculating left limit point coordinates corresponding to the edge surface of the pendulum saw when the pendulum saw is at the left limit and right limit point coordinates corresponding to the edge surface of the pendulum saw when the pendulum saw is at the right limit according to the updated search coordinate points and the planning direction vector of the pendulum saw.

Preferably, the step S3 includes:

step S31, traversing each boundary connecting line in the boundary connecting line set, calculating whether the connecting line between the left limit point and the right limit point is intersected with each boundary connecting line, if not, completing searching, and outputting the current searching coordinate point as the safety coordinate of the center point of the osteotomy pendulum saw; if the two parts are intersected, continuing the next step;

step S32, traversing each boundary connecting line in the boundary connecting line set, and calculating the distance from the current search coordinate point to each boundary connecting line and the coordinate of the nearest point;

step S33, traversing the distance from the current searching coordinate point to the boundary connecting line, searching the index numbers of the two boundary connecting lines with the shortest distance, and returning to the step S15.

Preferably, in the step S12, the calculating the distance from the center point of the osteotomy pendulum saw to each boundary line, and the coordinates of the nearest point include:

Judging the position relationship between the center point of the bone cutting swing saw and any boundary connecting line;

if the projection of the center point of the osteotomy swing saw on the boundary connecting line falls on the left extension line of the boundary connecting line, determining the coordinate of the left end point of the boundary connecting line as the nearest point coordinate, wherein the distance between the center point of the osteotomy swing saw and the left end point is the distance from the center point of the osteotomy swing saw to the boundary connecting line;

if the projection of the center point of the osteotomy swing saw on the boundary connecting line falls on the right extension line of the boundary connecting line, determining the coordinate of the right end point of the boundary connecting line as the nearest point coordinate, wherein the distance between the center point of the osteotomy swing saw and the right end point is the distance from the center point of the osteotomy swing saw to the boundary connecting line;

if the projection of the center point of the osteotomy swing saw on the boundary connecting line falls on the boundary connecting line, determining the projection point as the nearest point coordinate, wherein the distance between the center point of the osteotomy swing saw and the projection point is the distance between the center point of the osteotomy swing saw and the boundary connecting line.

Preferably, the determining the positional relationship between the center point of the osteotomy pendulum saw and any boundary line includes:

determining the left end point of the boundary connecting line as a vector starting point, wherein the vector direction of the boundary connecting line is that the left end point points to the right end point;

Calculating a connecting line vector between the left side end point and the central point of the osteotomy swing saw, and projecting the connecting line vector in the direction of the connecting line of the boundary;

if the length of the projection is less than or equal to 0, determining that the projection of the center point of the osteotomy swing saw on the boundary connecting line falls on the right extension line of the boundary connecting line;

if the length of the projection is greater than 0 and less than or equal to the vector length of the boundary connecting line, judging that the projection of the center point of the osteotomy swing saw on the boundary connecting line falls on the boundary connecting line;

if the length of the projection is greater than the vector length of the boundary connecting line, the projection of the center point of the osteotomy swing saw on the boundary connecting line is judged to fall on the right extension line of the boundary connecting line.

Preferably, the determining in step S14 whether the center point of the osteotomy swing saw is located in the boundary line set includes:

s141, generating a ray to infinity along any direction by taking the center point of the bone cutting swing saw as a starting point;

step S142, traversing each boundary point in the boundary point set, judging whether the ray passes through the boundary point, if so, returning to step S141, otherwise, carrying out the next step;

step S143, traversing each boundary line in the boundary line set, judging whether the ray coincides with the boundary line, if so, returning to step S141, otherwise, carrying out the next step;

Step S144, traversing each boundary connecting line in the boundary connecting line set, and calculating the number of intersection points where the ray intersects with the boundary connecting line;

step S145, if the number of the intersection points is an odd number, judging that the center point of the osteotomy swing saw is positioned in the boundary connecting line set; if the number of the intersection points is even, judging that the center point of the osteotomy swing saw is positioned outside the boundary connecting line set.

Preferably, traversing each boundary line in the boundary line set in step S31, calculating whether the line between the left limit point and the right limit point intersects each boundary line, includes:

for any boundary connecting line, calculating a connecting line vector between a right side endpoint and a left limit point of the boundary connecting line and a first rotation direction between the connecting line vector of the right side endpoint and the connecting line vector of the left side endpoint;

calculating a connection vector between a right side endpoint and a right limit point of the boundary connection line and a second rotation direction between the connection vector of the right side endpoint and the connection vector of the left side endpoint;

if the product of the first rotation direction and the second rotation direction is larger than 0, the connection line between the left limit point and the right limit point is judged to be not intersected with the boundary connection line.

Preferably, traversing each boundary line in the boundary line set in step S31, calculating whether the line between the left limit point and the right limit point intersects each boundary line, includes:

For any boundary connecting line, calculating a connecting line vector between a right limit point and a left side end point of the boundary connecting line and a third rotation direction between the connecting line vectors of the right limit point and the left limit point;

calculating a connection vector between a right limit point and a right side end point of the boundary connection line and a fourth rotation direction between the connection vector of the right limit point and the connection vector of the left limit point;

if the product of the third rotation direction and the fourth rotation direction is larger than 0, the connection line between the left limit point and the right limit point is judged to be not intersected with the boundary connection line.

According to a second aspect of the present invention, there is provided an osteotomy plane boundary control device, comprising:

the searching module is used for calculating the distance from the central point of the osteotomy pendulum saw to the boundary connecting line of the osteotomy plane, selecting the inward vector weighted summation of two sides with the shortest distance as the searching direction, and carrying out step-by-step searching;

the determining module is used for updating the coordinates of the searching points after each step searching is completed, and determining the coordinates of the left limit point and the coordinates of the right limit point corresponding to the cutting edge surface of the osteotomy pendulum saw according to the updated searching coordinate points;

the judging module is used for judging whether a connecting line between the left limit point and the right limit point is intersected with a boundary connecting line of the osteotomy plane, if not, completing searching, and outputting the current searching coordinate point as a safety coordinate of the central point of the osteotomy pendulum saw; if yes, returning to the searching module to recalculate the searching direction and carrying out step-by-step searching.

According to a third aspect of the present invention, there is provided an electronic device comprising:

the device comprises a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory are communicated with each other through the communication bus;

a memory for storing a computer program;

a processor for implementing the method of any one of claims 1 to 9 when executing a program stored on a memory.

According to a fourth aspect of the present invention there is provided a non-transitory computer readable storage medium storing computer instructions for causing a computer to perform the above-described method.

The technical scheme provided by the embodiment of the invention can comprise the following beneficial effects:

the distance from the center point of the osteotomy pendulum saw to the boundary connecting line of the osteotomy plane is calculated, the inward vectors of the two sides with the shortest distance are weighted and summed to be used as search directions, step search is performed to quickly find a safe position which is nearest to the boundary of the plane position (namely, accords with the expected movement direction and gesture) and is positioned in the boundary of the plane, and the safe position is sent to the mechanical arm to drive the operation tool to move, so that the doctor can accurately and safely help the osteotomy operation on the femur and the tibia. Solves the technical problem of soft tissue and ligament injury and operation precision reduction caused by overlarge movement range of the osteotomy pendulum saw in the prior art.

When the technical scheme provided by the embodiment is applied to the knee joint replacement operation robot, a doctor can be accurately and easily controlled to assist in performing osteotomy operation in the knee joint replacement operation, meanwhile, the boundary safety of the pendulum saw is ensured, the accuracy and success rate of the knee joint replacement operation are improved, and the burden of the doctor is lightened.

By applying the technical scheme provided by the embodiment, when a doctor performs planar osteotomy on the femur or tibia of a patient, and when the doctor needs to dynamically adjust the position of the osteotomy pendulum saw in a plane, the mechanical arm can limit a safety area dynamically adjusted by the doctor, so that the posterior cruciate ligament and the medial and lateral collateral ligaments of the patient are protected from being damaged, and the safety of the planar osteotomy is ensured.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.

Drawings

FIG. 1 is a flow chart of Total Knee Arthroplasty (TKA) shown in accordance with the background;

FIG. 2 is a flow chart illustrating a method of osteotomy plane boundary control, according to an exemplary embodiment;

FIG. 3 is a schematic view of a portion of a system architecture of a knee replacement surgical robot shown in accordance with an exemplary embodiment;

FIG. 4 is a schematic diagram illustrating an osteotomy pendulum saw tip control model, according to an exemplary embodiment;

FIG. 5 is a schematic view of an osteotomy plane boundary shown in accordance with an exemplary embodiment;

FIG. 6 is a schematic diagram illustrating osteotomy plane boundary control, according to an example embodiment;

FIG. 7 is a diagram illustrating a search process in a screenshot planar boundary control method according to another exemplary embodiment;

FIG. 8 is a schematic diagram showing the calculation of the distance from the center point of the osteotomy pendulum saw to any boundary line, and the coordinates of the closest point, according to an exemplary embodiment;

FIG. 9 is a schematic diagram illustrating a calculation for determining whether a center point of an osteotomy pendulum saw is located within a set of boundary lines, according to an exemplary embodiment;

FIG. 10 is a schematic diagram of a vector rotation direction calculation algorithm, shown according to an exemplary embodiment;

FIG. 11 is a schematic block diagram illustrating an osteotomy plane boundary control device, according to an exemplary embodiment;

fig. 12 is a schematic block diagram of an electronic device, according to an example embodiment.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

As described in the foregoing background art, the technical problem of reduced surgical accuracy caused by damage to soft tissues and ligaments due to an excessive range of motion of the osteotomy swing saw in the related art.

In order to effectively solve the problems in the related art, the invention provides an osteotomy plane boundary control method, an electronic device and a storage medium, and the method, the electronic device and the storage medium are specifically described below.

It should be noted that "connection lines" (such as a boundary connection line, a connection line between a left limit point and a right limit point) mentioned in the following embodiments include, but are not limited to: line segments, fold lines, curves, etc.

Example 1

FIG. 2 is a flowchart illustrating a method of osteotomy plane boundary control, see FIG. 2, according to an exemplary embodiment, the method comprising:

step S1, selecting the inward vector weighted summation of two sides with the shortest distance as a searching direction by calculating the distance from the central point of the osteotomy pendulum saw to the boundary connecting line of the osteotomy plane, and performing step-by-step searching;

step S2, after each step search is completed, updating the coordinates of the search points, and determining the coordinates of the left limit point and the coordinates of the right limit point corresponding to the cutting edge surface of the osteotomy pendulum saw according to the updated search coordinate points;

s3, judging whether a connecting line between the left limit point and the right limit point is intersected with a boundary connecting line of the osteotomy plane, if not, completing searching, and outputting the current searching coordinate point as a safety coordinate of a central point of the osteotomy pendulum saw; if yes, returning to the step S1 to recalculate the searching direction and carrying out step-by-step searching.

In the technical solution provided in this embodiment, in specific practice, the method is executed by the controller of the medical apparatus, or the method is executed by loading the program into an electronic device connected to the controller, where the program is stored in the electronic device.

The medical instrument may in particular be an orthopaedic surgical robot which may be suitable for use in procedures including, but not limited to, knee replacement procedures. The method can be suitable for the osteotomy plane boundary control in Total Knee Arthroplasty (TKA), can also be used for the osteotomy plane boundary control in unicondylar arthroplasty (UKA), or can be generalized to boundary control of any operative plane position.

It can be appreciated that, according to the technical scheme provided by the embodiment, by calculating the distance from the central point of the osteotomy pendulum saw to the boundary connecting line of the osteotomy plane, the inward vectors of the two sides with the shortest distance are selected to be weighted and summed, and used as the searching direction to perform step searching, so as to quickly find the safe position closest to the plane position boundary (i.e. in accordance with the expected movement direction and gesture) and located in the plane boundary, and then the safe position is issued to the mechanical arm to drive the operation tool to move, thereby accurately and safely helping doctors to realize the osteotomy operation on the femur and the tibia. Solves the technical problem of soft tissue and ligament injury and operation precision reduction caused by overlarge movement range of the osteotomy pendulum saw in the prior art.

When the technical scheme provided by the embodiment is applied to the knee joint replacement operation robot, a doctor can be accurately and easily controlled to assist in performing osteotomy operation in the knee joint replacement operation, meanwhile, the boundary safety of the pendulum saw is ensured, the accuracy and success rate of the knee joint replacement operation are improved, and the burden of the doctor is lightened.

Referring to fig. 3, the knee replacement surgical robot may include: motion control PC, robotic arm, six-dimensional force sensor, tool (osteotomy pendulum saw), and optical positioning sensor.

Referring to fig. 3, a six-dimensional force sensor is arranged at the tail end of the mechanical arm, and the force sensor is fixedly connected with the osteotomy pendulum saw. The doctor directly carries out interactive operation with the osteotomy pendulum saw in the art, then the motion control PC can be according to six-dimensional force sensor perception doctor interactive force, carries out power control through the specific size control arm of interactive force for the controlled interactive motion of osteotomy pendulum saw in the osteotomy plane. The optical positioning sensor is responsible for sensing the relative position relation between the patient and the tool in real time so that the motion control PC calculates and updates the plane pose information in real time.

It can be appreciated that by applying the technical scheme provided by the embodiment, when a doctor performs planar osteotomy on femur or tibia of a patient, and when the doctor needs to dynamically adjust the position of the osteotomy pendulum saw in a plane, the mechanical arm can limit a safety area dynamically adjusted by the doctor, so that the posterior cruciate ligament and the medial and lateral collateral ligaments of the patient are protected from being damaged, and the safety of the planar osteotomy is ensured.

FIG. 4 is a schematic view of a control model of the end of the osteotomy pendulum saw, see FIG. 4, v _saw For the direction vector of the pendulum saw, p _center For the end point coordinates, p, of the pendulum saw in the neutral position _left When the pendulum saw is at the left limit, the transverse displacement is projected to the left limit point coordinate corresponding to the pendulum saw blade surface, p _right The corresponding right limit point coordinates. When the end point coordinates and the direction vector of the pendulum saw are determined, the left and right limit position coordinates can be uniquely determined according to the mechanical structure design of the pendulum saw.

FIG. 5 is a schematic view of the boundary of the osteotomy plane, see FIG. 5, in which p _boundarys As boundary points, S _boundarys Is a polyline segment between boundary points. The initial and final boundary points extend backwards and infinitely along the initial and final fold line sections and are connected at infinity to form a plane position boundary. The polygon formed by the boundary folding line segments can be any concave-convex shape, and the method proposed by the embodiment does not limit the convexity of the boundary.

FIG. 6 is a schematic view of osteotomy plane boundary control, see FIG. 6, with p in the osteotomy plane _{center_plan} For the position of the osteotomy pendulum saw (possibly beyond the boundary) planned by the doctor's operating force, p _{center_safe} Is a safe position (guaranteed to be within the boundary) of the osteotomy swing saw. The safe position can control the tail end of the swing saw to move in the boundary of the plane position in the osteotomy plane, so that the posterior cruciate ligament and the medial collateral ligament of a patient are not damaged while the osteotomy task is finished, and the safety of the operation and the postoperative recovery effect of the patient are improved.

In specific practice, referring to fig. 7, the step S1 includes:

step S11, obtaining a planning coordinate p of a center point of the osteotomy pendulum saw _{center_plan} (x, y) planning direction vector v of osteotomy pendulum saw _saw (x, y) set of boundary points p of osteotomy plane _boundarys Boundary links consisting of sets of boundary pointsLine set S _boundarys Single step size inch _dist ；

Step S12, traversing the boundary connecting wire set S _boundarys Each boundary line of the line is takenCalculating the center point p of the osteotomy swing saw _{center_plan} To each boundary line->Distance dist of (2) ⁱ And, the nearest point coordinate p_close ⁱ ；

Step S13, calculating a central point p of the osteotomy swing saw _{center_plan} To boundary wireIndex number of the two border lines with shortest search distance +.>

Step S14, judging the center point p of the osteotomy pendulum saw _{center_plan} Whether or not to locate at the boundary line set S _boundarys If yes, initializing a planning coordinate p with a searching coordinate point equal to the center point of the osteotomy pendulum saw _iter ＝p _{center_plan} Otherwise, initializing the search coordinate point to be equal to the nearest point coordinate on the boundary line with the shortest distance

Step S15, calculating the search direction Wherein->Representing the edgeBoundary line set->A direction vector (unit vector) within the constituted directional boundary; to inch _dir And performing unitization operation to make the unitization operation be a unit vector.

In specific practice, the step S2 includes:

Step S21, step searching is carried out along the searching direction, and after each step searching is completed, the searching coordinate point is updated to be the sum p of the original searching coordinate point and the step amount in the searching direction _iter ＝p _iter +inch _dir *inch _dist ；

Step S22, searching coordinate point p according to the updated data _iter Planning direction vector v of the osteotomy pendulum saw _saw When the osteotomy pendulum saw is positioned at the left limit, calculating a left limit point coordinate p corresponding to the pendulum saw blade surface by transversely shifting and projecting _left And when the osteotomy pendulum saw is at the right limit, projecting the transverse displacement to a right limit point coordinate p corresponding to the pendulum saw blade surface _right 。

In specific practice, the step S3 includes:

step S31, traversing boundary connection line set S _boundarys Each boundary line of the line is takenCalculating the left limit point p _left And right limit point p _right The connection between the two and each boundary connection +.>If the current coordinate point is not intersected, completing searching, and outputting the current searching coordinate point as a safety coordinate p of the center point of the osteotomy pendulum saw _{center_safe} ＝p _iter The method comprises the steps of carrying out a first treatment on the surface of the If not, the two parts are intersected, and the next step is continued;

step S32, traversing the boundary connecting wire set S _boundarys Each boundary line of the line is takenCalculating the current search coordinate point p _iter To each boundary line->Distance dist of (2) ⁱ And, the nearest point coordinate p_close ⁱ ；

Step S33, traversing the current search coordinate point p _iter Distance to boundary line, searching index number of two boundary lines with shortest distanceReturning to step S15.

In specific practice, the maximum step searching times can be controlled by adjusting the stepping amount (generally controlling the stepping amount to be more than 1/20 and less than 1/10 of the width between the left limit and the right limit of the osteotomy pendulum saw), so as to restrict the searching time and ensure the time consumption of algorithm execution.

By the position boundary control method, when the position of the surgical tool planned by the operation force of the doctor exceeds the boundary, the position is corrected within the boundary range and accords with the position of the expected direction, so that the movement of the mechanical arm is controlled, and the operation of the doctor is adapted.

In specific practice, referring to fig. 8, in the step S12, the distance from the center point of the osteotomy pendulum saw to each boundary line is calculated, and the coordinates of the closest point include:

judging the position relationship between the center point of the bone cutting swing saw and any boundary connecting line;

if the projection of the center point of the osteotomy pendulum saw on the boundary line falls on the left extension line of the boundary line (in this case, the position of the center point of the osteotomy pendulum saw is shown as a point P1 in fig. 8), the coordinate of the left end point Pa of the boundary line is determined as the nearest point coordinate, and the distance between the center point P1 of the osteotomy pendulum saw and the left end point Pa is the distance from the center point of the osteotomy pendulum saw to the boundary line;

If the projection of the center point of the osteotomy pendulum saw on the boundary line falls on the right extension line of the boundary line (in this case, the position of the center point of the osteotomy pendulum saw is shown as a point P3 in fig. 8), the coordinate of the right end point Pb of the boundary line is determined as the nearest point coordinate, and the distance between the center point P3 of the osteotomy pendulum saw and the right end point Pb is the distance from the center point of the osteotomy pendulum saw to the boundary line;

if the projection of the center point of the osteotomy pendulum saw on the boundary line falls on the boundary line (in this case, the position of the center point of the osteotomy pendulum saw is shown as a point P2 in fig. 8), the projection point is determined as the nearest point coordinate, and the distance between the center point P2 of the osteotomy pendulum saw and the projection point is the distance from the center point of the osteotomy pendulum saw to the boundary line.

Referring to fig. 8, the determining the positional relationship between the center point of the osteotomy pendulum saw and any boundary line includes:

determining a left end point Pa of the boundary connecting line as a vector starting point, wherein the vector direction of the boundary connecting line is that the left end point Pa points to a right end point Pb;

calculating the left end point Pa and the center point P (P may be P) ₁ 、p ₂ 、p ₃ A point in (a) and a projection in the vector direction of the boundary line;

If the length of the projection is less than or equal to 0, determining that the projection of the center point P of the osteotomy swing saw on the boundary connecting line falls on the right extension line of the boundary connecting line;

if the length of the projection is greater than 0 and less than or equal to the vector length d of the boundary connecting line, judging that the projection of the center point P of the osteotomy pendulum saw on the boundary connecting line falls on the boundary connecting line;

if the length of the projection is greater than the vector length d of the boundary connecting line, the projection of the center point P of the osteotomy swing saw on the boundary connecting line is judged to fall on the right extension line of the boundary connecting line.

The above is expressed as: assume that the center point of the osteotomy pendulum saw is P (P) ₁ 、p ₂ 、p ₃ ) The boundary line is defined by point p _a 、p _b A line segment composed of a point p closest to the point p _min The following formula is adopted for calculation:

wherein, the liquid crystal display device comprises a liquid crystal display device,

d＝‖p _b -p _a ‖

then point p to from point p _a 、p _b The shortest distance of the composed line segments is calculated by the following formula:

D _min ＝‖p-p _min ‖

in specific practice, referring to fig. 9, the determining in step S14 whether the center point of the osteotomy pendulum saw is located in the boundary line set includes:

s141, generating a ray half_line to infinity along any direction by taking the center point P of the bone cutting swing saw as a starting point;

step S142, traversing the boundary point set p _boundarys Each boundary point of (1) is takenJudging whether the ray half_line passes through boundary point +.>If yes, returning to the step S141, otherwise, carrying out the next step;

step S143, traversing boundary connecting wire set S _boundarys Each boundary line of the line is takenJudging whether the ray half_line is connected with boundary line +.>Overlapping, if yes, returning to the step S141, otherwise, carrying out the next step;

step S144, traversing the boundary connecting wire set S _boundarys Each boundary connecting line in the list, calculating the ray half_line and the boundary connecting lineThe number n of intersecting points;

step S145, if the number n of intersection points is an odd number, determining that the center point P of the osteotomy swing saw is located in the boundary line set and flag=true; if the number n of the intersection points is even, determining that the center point P of the osteotomy pendulum saw is located outside the boundary line set flag=false.

In practical application, the ray may be equivalent to a line segment between the ray origin and a point at infinity in the ray direction, and then the intersection calculation between the ray and the line segment in S14 may be converted into the intersection detection of the line segment.

In specific practice, the step S31 of traversing each boundary line in the boundary line set, calculating whether the line between the left limit point and the right limit point intersects with each boundary line, includes:

For any boundary connecting line, calculating a connecting line vector between a right side endpoint and a left limit point of the boundary connecting line and a first rotation direction between the connecting line vector of the right side endpoint and the connecting line vector of the left side endpoint;

calculating a connection vector between a right side endpoint and a right limit point of the boundary connection line and a second rotation direction between the connection vector of the right side endpoint and the connection vector of the left side endpoint;

if the product of the first rotation direction and the second rotation direction is larger than 0, the connection line between the left limit point and the right limit point is judged to be not intersected with the boundary connection line.

For any boundary connecting line, calculating a connecting line vector between a right limit point and a left side end point of the boundary connecting line and a third rotation direction between the connecting line vectors of the right limit point and the left limit point;

calculating a connection vector between a right limit point and a right side end point of the boundary connection line and a fourth rotation direction between the connection vector of the right limit point and the connection vector of the left limit point;

if the product of the third rotation direction and the fourth rotation direction is larger than 0, the connection line between the left limit point and the right limit point is judged to be not intersected with the boundary connection line.

In order to facilitate understanding of each boundary line in the traversed boundary line set in step S31, a calculation process of calculating whether a line between the left limit point and the right limit point intersects any boundary line, now taking the left limit point as p _c And right limit point p _d The left end point of any boundary connecting line is p _a The right end point is p _b For example, referring to fig. 9, the explanation is as follows:

let kross (v) ₁ ,v ₂ ) To characterize the function of the direction of vector rotation, point p _a 、p _b Form line segment, point p _c 、p _d And if the line segments are formed, the following algorithm can be adopted to rapidly judge whether the two line segments are intersected:

wherein, the liquid crystal display device comprises a liquid crystal display device,

v _da ＝p _a -p _d

v _db ＝p _b -p _d

v _dc ＝p _c -p _d

v _ba ＝p _a -p _b

v _bc ＝p _c -p _b

referring to FIG. 10, the kross (v ₁ ,v ₂ ) The function is defined as:

two vectors v ₁ (x ₁ ,y ₁ )、v ₂ (x ₂ ,y ₂ ) The rotation direction between the two is calculated by the following method:

wherein, the liquid crystal display device comprises a liquid crystal display device,

kross(v ₁ ,v ₂ )＝x ₁ *y ₂ -x ₂ *y ₁

eps is a floating point number minimum, and is generally 0.000001.

It can be understood that, by the technical scheme provided by the embodiment, through the boundary control of the osteotomy plane, when the position of the surgical tool planned by the doctor operation force exceeds the boundary, the position is corrected to be within the designated boundary range and the position accords with the expected direction, thereby improving the success rate of the surgery.

In addition, the boundary control method of the osteotomy plane provided by the embodiment does not limit the convexity of the boundary, supports the custom boundary type according to the anatomy structure of the patient, can protect the posterior cruciate ligament and the medial collateral ligament of the patient from being damaged, and avoids unnecessary excessive cutting of soft tissues and ligaments.

Furthermore, according to the technical scheme provided by the embodiment, the safe position of the surgical tool is calculated according to the position of the surgical tool and the boundary of the safe surgical area planned by the operation force of a doctor, and the safe position of the surgical tool is issued to the mechanical arm to drive the surgical tool to move, so that the osteotomy of the femur and the tibia is accurately and safely realized. And only the expected position, the expected direction and the safety boundary of the osteotomy pendulum saw are needed, the current position and the current direction of the osteotomy pendulum saw are not needed to be acquired, the influence of the time lag of the system on the control is reduced, and the given safety direction of the osteotomy pendulum saw can be ensured to accord with the expected direction.

Example two

A method of osteotomy plane boundary control is shown in accordance with another exemplary embodiment, the method comprising:

step S11, obtaining a planning coordinate p of a center point of the osteotomy pendulum saw _{center_plan} (x, y) planning direction vector v of osteotomy pendulum saw _saw (x, y) set of boundary points p of osteotomy plane _boundarys Boundary line set S composed of boundary point set _boundarys Single step size inch _dist ；

Step S12, passCalendar said boundary line set S _boundarys Each boundary line of the line is takenCalculating the center point p of the osteotomy swing saw _{center_plan} To each boundary line->Distance dist of (2) ⁱ And, the nearest point coordinate p_close ⁱ ；

Step S13, calculating a central point p of the osteotomy swing saw _{center_plan} To boundary wireIndex number of the two border lines with shortest search distance +.>

Step S14, judging the center point p of the osteotomy pendulum saw _{center_plan} Whether or not to locate at the boundary line set S _boundarys If yes, initializing a planning coordinate p with a searching coordinate point equal to the center point of the osteotomy pendulum saw _iter ＝p _{center_plan} Otherwise, initializing the search coordinate point to be equal to the nearest point coordinate on the boundary line with the shortest distance

Step S15, calculating the search direction Wherein->Representing the boundary line set->A direction vector (unit vector) within the constituted directional boundary; to inch _dir Performing unitization operation to make the unitization operation be a unit vector;

step S21, step searching is carried out along the searching direction, and after each step searching is completed, the searching coordinate point is updated to be the sum p of the original searching coordinate point and the step amount in the searching direction _iter ＝p _iter +inch _dir *inch _dist ；

Step S22, searching coordinate point p according to the updated data _iter Planning direction vector v of the osteotomy pendulum saw _saw When the osteotomy pendulum saw is positioned at the left limit, calculating a left limit point coordinate p corresponding to the pendulum saw blade surface by transversely shifting and projecting _left And when the osteotomy pendulum saw is at the right limit, projecting the transverse displacement to a right limit point coordinate p corresponding to the pendulum saw blade surface _right ；

Step S31, traversing boundary connection line set S _boundarys Each boundary line of the line is takenCalculating the left limit point p _left And right limit point p _right The connection between the two and each boundary connection +.>If the current coordinate point is not intersected, completing searching, and outputting the current searching coordinate point as a safety coordinate p of the center point of the osteotomy pendulum saw _{center_safe} ＝p _iter The method comprises the steps of carrying out a first treatment on the surface of the If not, the two parts are intersected, and the next step is continued; />

Step S32, traversing the boundary connecting wire set S _boundarys Each boundary line of the line is takenCalculating the current search coordinate point p _iter To each boundary line->Distance dist of (2) ⁱ And, the nearest pointCoordinate p_close ⁱ ；

Step S33, traversing the current search coordinate point p _iter Distance to boundary line, searching index number of two boundary lines with shortest distanceReturning to step S15.

In the technical solution provided in this embodiment, in specific practice, the method is executed by the controller of the medical apparatus, or the method is executed by loading the program into an electronic device connected to the controller, where the program is stored in the electronic device.

The medical instrument may in particular be an orthopaedic surgical robot which may be suitable for use in procedures including, but not limited to, knee replacement procedures. The method can be suitable for the osteotomy plane boundary control in Total Knee Arthroplasty (TKA), can also be used for the osteotomy plane boundary control in unicondylar arthroplasty (UKA), or can be generalized to boundary control of any operative plane position.

It can be appreciated that, according to the technical scheme provided by the embodiment, by calculating the distance from the central point of the osteotomy pendulum saw to the boundary connecting line of the osteotomy plane, the inward vectors of the two sides with the shortest distance are selected to be weighted and summed, and used as the searching direction to perform step searching, so as to quickly find the safe position closest to the plane position boundary (i.e. in accordance with the expected movement direction and gesture) and located in the plane boundary, and then the safe position is issued to the mechanical arm to drive the operation tool to move, thereby accurately and safely helping doctors to realize the osteotomy operation on the femur and the tibia. Solves the technical problem of soft tissue and ligament injury and operation precision reduction caused by overlarge movement range of the osteotomy pendulum saw in the prior art.

When the technical scheme provided by the embodiment is applied to the knee joint replacement operation robot, a doctor can be accurately and easily controlled to assist in performing osteotomy operation in the knee joint replacement operation, meanwhile, the boundary safety of the pendulum saw is ensured, the accuracy and success rate of the knee joint replacement operation are improved, and the burden of the doctor is lightened.

In addition, the boundary control method of the osteotomy plane provided by the embodiment does not limit the convexity of the boundary, supports the custom boundary type according to the anatomy structure of the patient, can protect the posterior cruciate ligament and the medial collateral ligament of the patient from being damaged, and avoids unnecessary excessive cutting of soft tissues and ligaments.

Furthermore, according to the technical scheme provided by the embodiment, the safe position of the surgical tool is calculated according to the position of the surgical tool and the boundary of the safe surgical area planned by the operation force of a doctor, and the safe position of the surgical tool is issued to the mechanical arm to drive the surgical tool to move, so that the osteotomy of the femur and the tibia is accurately and safely realized. And only the expected position, the expected direction and the safety boundary of the osteotomy pendulum saw are needed, the current position and the current direction of the osteotomy pendulum saw are not needed to be acquired, the influence of the time lag of the system on the control is reduced, and the given safety direction of the osteotomy pendulum saw can be ensured to accord with the expected direction.

Example III

Based on the same concept, referring to fig. 11, an osteotomy plane boundary control device 100 is shown according to an exemplary embodiment, comprising:

the searching module 101 is used for calculating the distance from the central point of the osteotomy pendulum saw to the boundary connecting line of the osteotomy plane, selecting the inward vector weighted summation of two sides with the shortest distance as the searching direction, and performing step-by-step searching;

the determining module 102 is configured to update the coordinates of the search points after each step search is completed, and determine the coordinates of the left limit point and the coordinates of the right limit point corresponding to the cutting edge surface of the osteotomy pendulum saw according to the updated search coordinate points;

The judging module 103 is configured to judge whether a connecting line between the left limit point and the right limit point intersects with a boundary connecting line of the osteotomy plane, if not, complete searching, and output the current searching coordinate point as a safety coordinate of a central point of the osteotomy pendulum saw; if yes, returning to the searching module to recalculate the searching direction and carrying out step-by-step searching.

It should be noted that, the implementation manner and beneficial effects of each module may be referred to the description of the related steps of the foregoing embodiment, which is not repeated in this embodiment.

It can be appreciated that, according to the technical scheme provided by the embodiment, by calculating the distance from the central point of the osteotomy pendulum saw to the boundary connecting line of the osteotomy plane, the inward vectors of the two sides with the shortest distance are selected to be weighted and summed, and used as the searching direction to perform step searching, so as to quickly find the safe position closest to the plane position boundary (i.e. in accordance with the expected movement direction and gesture) and located in the plane boundary, and then the safe position is issued to the mechanical arm to drive the operation tool to move, thereby accurately and safely helping doctors to realize the osteotomy operation on the femur and the tibia. Solves the technical problem of soft tissue and ligament injury and operation precision reduction caused by overlarge movement range of the osteotomy pendulum saw in the prior art.

Example IV

Referring to fig. 12, an electronic device is shown according to an exemplary embodiment, comprising:

a processor 701, a communication interface 702, a memory 703 and a communication bus 704, wherein the processor 701, the communication interface 702 and the memory 703 complete communication with each other through the communication bus 704;

a memory 703 for storing a computer program;

the processor 701 is configured to implement the above-described method when executing the program stored in the memory.

It can be appreciated that, according to the technical scheme provided by the embodiment, by calculating the distance from the central point of the osteotomy pendulum saw to the boundary connecting line of the osteotomy plane, the inward vectors of the two sides with the shortest distance are selected to be weighted and summed, and used as the searching direction to perform step searching, so as to quickly find the safe position closest to the plane position boundary (i.e. in accordance with the expected movement direction and gesture) and located in the plane boundary, and then the safe position is issued to the mechanical arm to drive the operation tool to move, thereby accurately and safely helping doctors to realize the osteotomy operation on the femur and the tibia. Solves the technical problem of soft tissue and ligament injury and operation precision reduction caused by overlarge movement range of the osteotomy pendulum saw in the prior art.

Example five

A non-transitory computer readable storage medium storing computer instructions for causing a computer to perform the above-described method is shown according to an exemplary embodiment.

It can be appreciated that, according to the technical scheme provided by the embodiment, by calculating the distance from the central point of the osteotomy pendulum saw to the boundary connecting line of the osteotomy plane, the inward vectors of the two sides with the shortest distance are selected to be weighted and summed, and used as the searching direction to perform step searching, so as to quickly find the safe position closest to the plane position boundary (i.e. in accordance with the expected movement direction and gesture) and located in the plane boundary, and then the safe position is issued to the mechanical arm to drive the operation tool to move, thereby accurately and safely helping doctors to realize the osteotomy operation on the femur and the tibia. Solves the technical problem of soft tissue and ligament injury and operation precision reduction caused by overlarge movement range of the osteotomy pendulum saw in the prior art.

Of course, those skilled in the art will appreciate that implementing all or part of the above-described methods may be implemented by a computer program for instructing relevant hardware (e.g., a processor, a controller, etc.), where the program may be stored in a computer-readable storage medium, and where the program may include the steps of the above-described method embodiments when executed. The storage medium may be a memory, a magnetic disk, an optical disk, or the like.

The above-described embodiments of the present invention do not limit the scope of the present invention. Any other corresponding changes and modifications made in accordance with the technical idea of the present invention shall be included in the scope of the claims of the present invention.

Claims (12)

1. A method for osteotomy plane boundary control, comprising:

step S1, calculating the distance from the center point of the osteotomy swing saw to the boundary connecting line of the osteotomy plane, selecting the inward vector weighted summation of two sides with the shortest distance as the searching direction, and performing step-by-step searching;

step S2, after each step search is completed, updating the coordinates of the search points, and determining the coordinates of the left limit point and the coordinates of the right limit point corresponding to the cutting edge surface of the osteotomy pendulum saw according to the updated search coordinate points;

s3, judging whether a connecting line between the left limit point and the right limit point is intersected with a boundary connecting line of the osteotomy plane, if not, completing searching, and outputting the current searching coordinate point as a safety coordinate of a central point of the osteotomy pendulum saw; if yes, returning to the step S1 to recalculate the searching direction and carrying out step-by-step searching.

2. The method according to claim 1, wherein the step S1 comprises:

Step S11, acquiring planning coordinates of a central point of the osteotomy pendulum saw, a planning direction vector of the osteotomy pendulum saw, a boundary point set of an osteotomy plane, and a boundary line set formed by the boundary point set, wherein the single stepping quantity is obtained;

step S12, traversing each boundary connecting line in the boundary connecting line set, and calculating the distance from the center point of the osteotomy pendulum saw to each boundary connecting line and the coordinate of the nearest point;

step S13, traversing the distance from the center point of the osteotomy pendulum saw to the boundary connecting line, and searching index numbers of two boundary connecting lines with the shortest distance;

step S14, judging whether the center point of the osteotomy pendulum saw is positioned in the boundary connecting line set, if yes, initializing a searching coordinate point to be equal to the planning coordinate of the center point of the osteotomy pendulum saw, otherwise, initializing the searching coordinate point to be equal to the nearest point coordinate on the shortest boundary connecting line;

and S15, calculating a search direction, wherein the search direction is the weighted summation of the direction vectors of the two boundary connecting lines with the shortest distance, and the weight value of the direction vector of each boundary connecting line is the distance value between the other boundary connecting line and the center point of the osteotomy swing saw.

3. The method according to claim 2, wherein the step S2 comprises:

Step S21, step searching is carried out along the searching direction, and after each step searching is completed, the searching coordinate point is updated to be the sum of the original searching coordinate point and the step amount in the searching direction;

and S22, calculating left limit point coordinates corresponding to the edge surface of the pendulum saw when the pendulum saw is at the left limit and right limit point coordinates corresponding to the edge surface of the pendulum saw when the pendulum saw is at the right limit according to the updated search coordinate points and the planning direction vector of the pendulum saw.

4. A method according to claim 3, wherein said step S3 comprises:

step S31, traversing each boundary connecting line in the boundary connecting line set, calculating whether the connecting line between the left limit point and the right limit point is intersected with each boundary connecting line, if not, completing searching, and outputting the current searching coordinate point as the safety coordinate of the center point of the osteotomy pendulum saw; if the two parts are intersected, continuing the next step;

step S32, traversing each boundary connecting line in the boundary connecting line set, and calculating the distance from the current search coordinate point to each boundary connecting line and the coordinate of the nearest point;

step S33, traversing the distance from the current searching coordinate point to the boundary connecting line, searching the index numbers of the two boundary connecting lines with the shortest distance, and returning to the step S15.

5. The method according to claim 2, wherein the calculating the distance from the center point of the osteotomy pendulum saw to each boundary line in step S12, and the closest point coordinates, includes:

judging the position relationship between the center point of the bone cutting swing saw and any boundary connecting line;

if the projection of the center point of the osteotomy swing saw on the boundary connecting line falls on the left extension line of the boundary connecting line, determining the coordinate of the left end point of the boundary connecting line as the nearest point coordinate, wherein the distance between the center point of the osteotomy swing saw and the left end point is the distance from the center point of the osteotomy swing saw to the boundary connecting line;

if the projection of the center point of the osteotomy swing saw on the boundary connecting line falls on the right extension line of the boundary connecting line, determining the coordinate of the right end point of the boundary connecting line as the nearest point coordinate, wherein the distance between the center point of the osteotomy swing saw and the right end point is the distance from the center point of the osteotomy swing saw to the boundary connecting line;

if the projection of the center point of the osteotomy swing saw on the boundary connecting line falls on the boundary connecting line, determining the projection point as the nearest point coordinate, wherein the distance between the center point of the osteotomy swing saw and the projection point is the distance between the center point of the osteotomy swing saw and the boundary connecting line.

6. The method of claim 5, wherein determining the positional relationship between the center point of the osteotomy pendulum saw and any one of the border lines comprises:

determining the left end point of the boundary connecting line as a vector starting point, wherein the vector direction of the boundary connecting line is that the left end point points to the right end point;

calculating a connecting line vector between the left side end point and the central point of the osteotomy swing saw, and projecting the connecting line vector in the direction of the connecting line of the boundary;

if the length of the projection is less than or equal to 0, determining that the projection of the center point of the osteotomy swing saw on the boundary connecting line falls on the right extension line of the boundary connecting line;

if the length of the projection is greater than 0 and less than or equal to the vector length of the boundary connecting line, judging that the projection of the center point of the osteotomy swing saw on the boundary connecting line falls on the boundary connecting line;

if the length of the projection is greater than the vector length of the boundary connecting line, the projection of the center point of the osteotomy swing saw on the boundary connecting line is judged to fall on the right extension line of the boundary connecting line.

7. The method according to claim 2, wherein determining in step S14 whether the center point of the osteotomy wobble saw is located within the boundary wire set comprises:

S141, generating a ray to infinity along any direction by taking the center point of the bone cutting swing saw as a starting point;

step S142, traversing each boundary point in the boundary point set, judging whether the ray passes through the boundary point, if so, returning to step S141, otherwise, carrying out the next step;

step S143, traversing each boundary line in the boundary line set, judging whether the ray coincides with the boundary line, if so, returning to step S141, otherwise, carrying out the next step;

step S144, traversing each boundary connecting line in the boundary connecting line set, and calculating the number of intersection points where the ray intersects with the boundary connecting line;

step S145, if the number of the intersection points is an odd number, judging that the center point of the osteotomy swing saw is positioned in the boundary connecting line set; if the number of the intersection points is even, judging that the center point of the osteotomy swing saw is positioned outside the boundary connecting line set.

8. The method according to claim 4, wherein traversing each boundary line in the set of boundary lines in step S31, calculating whether the line between the left limit point and the right limit point intersects each boundary line, comprises:

for any boundary connecting line, calculating a connecting line vector between a right side endpoint and a left limit point of the boundary connecting line and a first rotation direction between the connecting line vector of the right side endpoint and the connecting line vector of the left side endpoint;

Calculating a connection vector between a right side endpoint and a right limit point of the boundary connection line and a second rotation direction between the connection vector of the right side endpoint and the connection vector of the left side endpoint;

if the product of the first rotation direction and the second rotation direction is larger than 0, the connection line between the left limit point and the right limit point is judged to be not intersected with the boundary connection line.

9. The method according to claim 4, wherein traversing each boundary line in the set of boundary lines in step S31, calculating whether the line between the left limit point and the right limit point intersects each boundary line, comprises:

for any boundary connecting line, calculating a connecting line vector between a right limit point and a left side end point of the boundary connecting line and a third rotation direction between the connecting line vectors of the right limit point and the left limit point;

calculating a connection vector between a right limit point and a right side end point of the boundary connection line and a fourth rotation direction between the connection vector of the right limit point and the connection vector of the left limit point;

if the product of the third rotation direction and the fourth rotation direction is larger than 0, the connection line between the left limit point and the right limit point is judged to be not intersected with the boundary connection line.

10. An osteotomy plane boundary control device, comprising:

The searching module is used for calculating the distance from the central point of the osteotomy pendulum saw to the boundary connecting line of the osteotomy plane, selecting the inward vector weighted summation of two sides with the shortest distance as the searching direction, and carrying out step-by-step searching;

the determining module is used for updating the coordinates of the searching points after each step searching is completed, and determining the coordinates of the left limit point and the coordinates of the right limit point corresponding to the cutting edge surface of the osteotomy pendulum saw according to the updated searching coordinate points;

the judging module is used for judging whether a connecting line between the left limit point and the right limit point is intersected with a boundary connecting line of the osteotomy plane, if not, completing searching, and outputting the current searching coordinate point as a safety coordinate of the central point of the osteotomy pendulum saw; if yes, returning to the searching module to recalculate the searching direction and carrying out step-by-step searching.

11. An electronic device, comprising:

the device comprises a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory are communicated with each other through the communication bus;

a memory for storing a computer program;

a processor for implementing the method of any one of claims 1 to 9 when executing a program stored on a memory.

12. A non-transitory computer readable storage medium storing computer instructions for causing a computer to perform the method of any one of claims 1-9.