Apparatus for high tibial osteotomy surgery and control method thereof

Abstract

The present disclosure provides an apparatus for tibial high osteotomy surgery and a control method thereof. The mechanical arm end of the apparatus is provided with a surgical instrument, and the control method comprises: constraining an initial action force by using a virtual clamp to obtain a target action force; determining a mobility parameter of a mobility control model based on the mobility control model, according to the current state of the surgical instrument, the target action force, and the speed of the surgical instrument at the current time; and determining the speed of the surgical instrument at the next time based on the mobility parameter and the target action force, so as to control the movement of the surgical instrument based on the speed at the next time.

Description

Technical Field

[0001] This disclosure relates to the field of human-machine interaction control for robotic arms, and more particularly to a device and control method for high tibial osteotomy. Background Technology

[0002] High tibial osteotomy (HTO) is a surgical procedure used to treat knee osteoarthritis. It corrects the lower limb alignment by cutting the tibia to alleviate joint disease and has advantages such as high safety and good stability of the osteotomy surface.

[0003] Equipment used in high tibial osteotomy (HTO) can assist surgeons in completing the osteotomy phase of the procedure. However, the control methods for these devices suffer from drawbacks such as low control precision, poor adaptability, and low safety. Summary of the Invention

[0004] In view of this, the present disclosure provides a control method for a device used in high tibial osteotomy surgery, wherein the end of the robotic arm of the device is provided with a surgical instrument, and the control method includes: using a virtual clamp to constrain an initial force to obtain a target force; based on an admittance control model, determining the admittance parameters of the admittance control model according to the current state of the surgical instrument, the target force, and the current velocity of the surgical instrument; and based on the admittance parameters and the target force, determining the velocity of the surgical instrument at the next moment, thereby controlling the movement of the surgical instrument based on the velocity at the next moment.

[0005] Optionally, the virtual fixture includes a guiding virtual fixture and a prohibiting virtual fixture. The step of using the virtual fixture to constrain the initial force to obtain the target force includes: using the guiding virtual fixture to constrain the initial force in a second direction and a first direction, and using the prohibiting virtual fixture to constrain the initial force in a third direction to obtain the target force; wherein the second direction, the first direction, and the third direction are perpendicular to each other, and the second direction and the third direction are parallel to the horizontal plane.

[0006] Optionally, constraining the initial force in the second and first directions using the guided virtual clamp includes: constraining the initial force in the second and first directions using the guided virtual clamp based on a predetermined height and a predetermined width.

[0007] Optionally, constraining the initial force in a third-party direction using the prohibition-type virtual clamp includes: constraining the initial force in a third-party direction using the prohibition-type virtual clamp based on the cross-sectional profile shape of the tibia and a predetermined distance, wherein the predetermined distance is characterized as the maximum distance from the edge of the cross-sectional profile of the tibia.

[0008] Optionally, determining the admittance parameters of the admittance control model based on the admittance control model, according to the current state of the surgical instrument, the target force, and the current velocity of the surgical instrument, includes: determining the range of the admittance parameters based on the current state of the surgical instrument; and determining the admittance parameters of the admittance control model using a fuzzy inference system based on the range of the admittance parameters, the target force, and the current velocity of the surgical instrument.

[0009] Optionally, the current state of the surgical instruments is determined based on the reaction force acting on the surgical instruments of the device.

[0010] Optionally, the current state includes one of the following: free state, cortical bone resection state, cancellous bone resection state, and regression state.

[0011] Optionally, the admittance parameter includes virtual damping.

[0012] This disclosure provides an apparatus for high tibial osteotomy, comprising: a robotic arm; surgical instruments disposed at the end of the robotic arm; and a control device that uses the above-described control method to control the robotic arm to move the surgical instruments.

[0013] Optionally, the device further includes a force sensor disposed between the robotic arm and the surgical instrument, the force sensor being configured to detect the force acting on the surgical instrument.

[0014] According to embodiments of this disclosure, the initial force can be represented as the force applied to the surgical instrument by a doctor or user to drag it to a predetermined position. The surgical instrument can be an oscillating saw or other instrument used for osteotomy. However, if the doctor or user operates improperly, the instrument may collide with the doctor or other medical equipment during dragging, resulting in the tibia being cut or vital tissues such as blood vessels being severed. To avoid these situations, a virtual clamp can be used to constrain the initial force, controlling the surgical instrument within a predetermined range and ensuring that the instrument moves in the direction of the target force, thereby improving the accuracy and safety of control. Attached Figure Description

[0015] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0016] Figure 1 A flowchart illustrating a control method for an apparatus for high tibial osteotomy according to an embodiment of the present invention is shown.

[0017] Figure 2 A schematic diagram illustrating the positional relationship between the guide surface and the tibia according to an embodiment of the present invention is shown.

[0018] Figure 3 The diagram schematically illustrates the positional relationship between the cross-sectional profile of the tibia and the boundary of the constraint region according to an embodiment of the present invention.

[0019] Figure 4 The diagram illustrates the positional relationship between the guide surface and the boundary of the constraint region according to an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. However, the present invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided to make the disclosure thorough and complete, and to fully convey the scope of the invention to those skilled in the art. In the accompanying drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated, and the same reference numerals denote the same elements throughout.

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the invention. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “comprising,” “including,” etc., as used herein indicate the presence of features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0023] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0024] To facilitate understanding of the technical solutions of this invention by those skilled in the art, the following technical terms are explained below.

[0025] When using expressions such as "at least one of A, B, and C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). When using expressions such as "at least one of A, B, or C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0026] Figure 1 A flowchart illustrating a control method for an apparatus for high tibial osteotomy according to an embodiment of the present invention is shown.

[0027] like Figure 1 As shown, this embodiment of the invention provides a control method for a device used in high tibial osteotomy. The device's robotic arm has surgical instruments at its end. The control method may include the following steps S110-S130.

[0028] In step S110, the target force is obtained by using the virtual fixture to constrain the initial force.

[0029] According to embodiments of this disclosure, the initial force can be represented as the force applied to the surgical instrument by a doctor or user to drag it to a predetermined position. The surgical instrument can be an oscillating saw or other instrument used for osteotomy. However, if the doctor or user operates improperly, the instrument may collide with the doctor or other medical equipment during dragging, resulting in the tibia being cut or vital tissues such as blood vessels being severed. To avoid these situations, a virtual clamp can be used to constrain the initial force, controlling the surgical instrument within a predetermined range and ensuring that the instrument moves in the direction of the target force, thereby improving the accuracy and safety of control.

[0030] In step S120, based on the admittance control model, the admittance parameters of the admittance control model are determined according to the current state of the surgical instrument, the target force, and the current velocity of the surgical instrument.

[0031] In step S130, the velocity of the surgical instrument at the next moment is determined based on the admittance parameter and the target force, thereby controlling the movement of the surgical instrument based on the velocity at the next moment.

[0032] According to embodiments of this disclosure, the admittance control model is a robot control strategy based on force-motion interaction. Determining the admittance parameters of the admittance control model according to the current state of the surgical instrument can improve its adaptability, thereby enhancing control compliance.

[0033] According to embodiments of this disclosure, the current state of the surgical instrument can be characterized as the specific operational stage of the high tibial osteotomy surgery in which the surgical instrument is located.

[0034] According to embodiments of this disclosure, by utilizing a virtual clamp to constrain the initial force, surgical instruments can be controlled within a predetermined range, causing them to move in the direction of the target force, thereby improving control accuracy and safety. Determining the admittance parameters of the admittance control model based on the current state of the surgical instruments can improve the adaptability of the admittance control model, thus enhancing control compliance.

[0035] In some illustrative embodiments, the virtual fixture includes guided virtual fixtures and prohibited virtual fixtures.

[0036] Step S110 may include: using a guided virtual fixture to constrain the initial force in the second and first directions, and using a guided virtual fixture to constrain the initial force in the third direction to obtain the target force.

[0037] According to embodiments of this disclosure, the second direction, the first direction, and the third direction are perpendicular to each other, and the second direction and the third direction are parallel to the horizontal plane.

[0038] In some illustrative embodiments, constraining the initial force in the second and first directions using a guided virtual fixture includes: constraining the initial force in the second and first directions using the guided virtual fixture based on a predetermined height and a predetermined width.

[0039] According to embodiments of this disclosure, using a guided virtual jig to constrain the initial force in the second direction can be represented as controlling the surgical instrument within a predetermined width range. Using a guided virtual jig to constrain the initial force in the first direction can be represented as controlling the surgical instrument within a predetermined height range. The predetermined height and predetermined width can be set according to the surgeon's preoperative planning. For example, the predetermined width can be represented as the maximum width of the tibial osteotomy surface.

[0040] Figure 2 A schematic diagram illustrating the positional relationship between the guide surface and the tibia according to an embodiment of the present invention is shown.

[0041] According to embodiments of this disclosure, a guided virtual fixture can limit the target force as follows: Figure 2 Within the guide surface G shown. (As shown) Figure 2As shown, a first virtual boundary line l1 and a second virtual boundary line l2 can be set based on a predetermined width and a predetermined height. The guide surface G can be represented as a plane formed by the first virtual boundary line l1 and the second virtual boundary line l2, and the first virtual boundary line l1 and the second virtual boundary line l2 are the boundary lines of the guide surface G.

[0042] According to embodiments of this disclosure, after the guided virtual fixture constrains the initial force in the first direction, the initial force can be determined by force. It means, force It can be represented by the following expression (1).

[0043] (1).

[0044] in, This represents the initial, unrestrained force. This represents the normal vector of the osteotomy surface, i.e., the first direction.

[0045] According to embodiments of this disclosure, the guided virtual fixture exerts a constraint force on the initial force in the second direction. It can be represented by the following expression (2).

[0046] (2).

[0047] in, , This represents the distance between the surgical instrument and the midline between the first virtual boundary line l1 and the second virtual boundary line l2. This represents the distance from the first virtual boundary line l1 and / or the second virtual boundary line l2 to the centerline. This represents the pre-set buffer limit width. Less than 2 Indicates the predetermined width.

[0048] Figure 3 The diagram schematically illustrates the positional relationship between the cross-sectional profile of the tibia and the boundary of the constraint region according to an embodiment of the present invention. Figure 4 The diagram illustrates the positional relationship between the guide surface and the boundary of the constraint region according to an embodiment of the present invention.

[0049] In some illustrative embodiments, the initial force is constrained in a third-party direction using a prohibition-type virtual clamp, including: constraining the initial force in a third-party direction using a prohibition-type virtual clamp based on the cross-sectional profile shape of the tibia and a predetermined distance.

[0050] like Figure 3As shown, the predetermined distance d1 represents the maximum distance from the edge of the tibial cross-sectional profile P. The predetermined distance d1 can be set according to the surgeon's preoperative planning. For example, the predetermined distance d1 can be 1 cm.

[0051] According to embodiments of this disclosure, using a prohibition-type virtual clamp to constrain the initial force in a third direction can be represented as controlling the surgical instrument within a predetermined length range. The predetermined length can be set according to the surgeon's preoperative planning. For example, the predetermined length range can be represented as a range where the distance from the cross-sectional profile of the tibia is greater than a predetermined distance. That is, a constraint region boundary Q can be formed inside the cross-sectional profile of the tibia.

[0052] like Figure 4 As shown, after using a prohibition-type virtual fixture to constrain the initial force in the third direction, a constraint area boundary Q can be formed on the guide surface to further limit the range of motion of the surgical instruments.

[0053] According to embodiments of this disclosure, the surgical instrument used for osteotomy is an oscillating mechanism. During the immobilization process using a prohibition-type virtual clamp based on the cross-sectional profile of the tibia, the end position of the surgical instrument can be determined by its maximum oscillation amplitude. Furthermore, an artificial potential field can be introduced into the prohibition-type virtual clamp, and the constraint force of the prohibition-type virtual clamp on the initial force is determined by the end position of the surgical instrument. It can be represented by the following expression (3).

[0054] (3).

[0055] in, The scale factor is the scale factor of the artificial potential field, and a predetermined distance can be set based on the scale factor. This is the distance between the tip of the surgical instrument and the cross-sectional profile of the tibia. To constrain the boundaries of the region.

[0056] According to embodiments of this disclosure, the range of the target force can be determined experimentally, allowing... The maximum value is the maximum value of the target force, to avoid the distance approaching 0, constraint force. The case of infinity.

[0057] According to embodiments of this disclosure, by using guided virtual clamps and prohibited virtual clamps to constrain the initial force, the positioning accuracy of osteotomy can be improved. During the dragging process, the surgical instruments are guided and restricted to avoid collisions with relevant medical personnel or medical equipment. Furthermore, during the osteotomy process, the osteotomy area of ​​the surgical instruments is restricted to avoid cutting the tibia or important tissues such as blood vessels, thereby improving safety.

[0058] In some illustrative embodiments, step S120 may include the following steps S121 to S122.

[0059] In step S121, the range of admittance parameters is determined based on the current state of the surgical instruments.

[0060] In some illustrative embodiments, the current state of the surgical instruments is determined based on the reaction force acting on them.

[0061] According to embodiments of this disclosure, a force sensor can be connected between the robotic arm and the surgical instruments. During osteotomy, the tibia exerts a reaction force on the surgical instruments. The rate of change of the reaction force exerted by the tibia on the surgical instruments varies at different stages of the procedure. The current state of the surgical instruments can be determined based on the rate of change of the reaction force detected by the force sensor and the direction information of the force and velocity.

[0062] In some illustrative embodiments, the current state may include any one of the following: a free state, a cortical bone resection state, a cancellous bone resection state, and a regressed state.

[0063] According to embodiments of this disclosure, the free state can be represented as the state before the surgical instruments have come into contact with the human body.

[0064] According to embodiments of this disclosure, the cortical bone resection state can be represented as the transition of surgical instruments from a free state to the cortical bone resection state. During this stage, the environmental stiffness increases, and the resultant force measured by the force sensor decreases instantaneously, with a negative rate of change of the resultant force. The resultant force can be represented as the sum of the initial action force and the reaction force.

[0065] According to embodiments of this disclosure, the cancellous bone resection state can be represented as the transition from cortical bone to cancellous bone when surgical instruments cut through the cortical bone. During this stage, the environmental stiffness decreases, the resultant force increases instantaneously, and the rate of change of the resultant force increases.

[0066] According to embodiments of this disclosure, the retraction state can be represented as the retraction of the surgical instrument during the reciprocating osteotomy. During this stage, the surgical instrument gradually moves away from the boundary of the restraint area.

[0067] In step S122, based on the admittance control model, the admittance parameters of the admittance control model are determined using a fuzzy inference system according to the range of admittance parameters, the target force, and the current velocity of the surgical instrument.

[0068] According to an embodiment of this disclosure, the admittance control model can be represented by the following expression (4).

[0069] (4).

[0070] in, For the target force, M represents virtual inertia. B represents virtual damping. Indicates the speed of surgical instruments. This indicates the acceleration of the surgical instruments.

[0071] According to embodiments of this disclosure, the range of admittance parameters for different states can be determined by adjusting the admittance parameters for four states. Based on the reaction force, the admittance parameters can be determined using a fuzzy inference system.

[0072] In some illustrative embodiments, the admittance parameter includes virtual damping.

[0073] This disclosure also provides an apparatus for high tibial osteotomy. The apparatus may include a robotic arm, surgical instruments, and a control device. The surgical instruments are disposed at the end of the robotic arm. The control device uses the control method described above to control the movement of the robotic arm and the surgical instruments.

[0074] In some illustrative embodiments, the device also includes a force sensor. The force sensor is positioned between the robotic arm and the surgical instruments. The force sensor can be used to detect the forces acting on the surgical instruments.

[0075] According to embodiments of this disclosure, since the force obtained by the force sensor is the force in the force sensor coordinate system, for ease of calculation, the force detected by the force sensor can be... Converted into the initial force in the surgical instrument coordinate system Furthermore, it can be transformed using the following expression (5).

[0076] (5).

[0077] in , , , These are the three coordinate values ​​of the origin of the force sensor coordinate system in the surgical instrument coordinate system. The coordinates of the origin of the surgical instrument coordinate system in the world coordinate system.

[0078] According to embodiments of this disclosure, speed may include linear velocity and angular velocity, wherein the linear velocity of the surgical instrument is determined. and angular velocity Then, the linear velocity of the robotic arm can be determined. and angular velocity This allows for the control of the robotic arm's movement.

[0079] The speed and acceleration of the robotic arm can be represented by the following expression (6).

[0080] (6).

[0081] in, , , , It can represent the coordinates of the surgical instruments in the robotic arm coordinate system. This is the rotation matrix of the robotic arm coordinate system relative to the surgical instrument coordinate system.

[0082] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0083] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A device for high tibial osteotomy, characterized in that, include: robotic arm; Surgical instruments are located at the end of the robotic arm; as well as A control device that implements a control method, the control method comprising: Based on a predetermined height and width, a guiding virtual fixture is used to constrain the initial force in the second and first directions, and a prohibition virtual fixture is used to constrain the initial force in the third direction based on the cross-sectional profile shape and predetermined distance of the tibia, thereby obtaining the target force; wherein, the predetermined distance is characterized as the maximum distance from the edge of the cross-sectional profile of the tibia; Based on the admittance control model, the admittance parameters of the admittance control model are determined according to the current state of the surgical instrument, the target force, and the current velocity of the surgical instrument; and Based on the admittance parameter and the target force, the velocity of the surgical instrument at the next moment is determined, and the movement of the surgical instrument is controlled based on the velocity at the next moment. Wherein, the second direction, the first direction, and the third direction are perpendicular to each other, and the second direction and the third direction are parallel to the horizontal plane.

2. The device according to claim 1, characterized in that, The admittance-based control model determines the admittance parameters of the admittance control model based on the current state of the surgical instrument, the target force, and the current velocity of the surgical instrument, including: The range of the admittance parameter is determined based on the current state of the surgical instrument; Based on the admittance control model, the admittance parameters of the admittance control model are determined using a fuzzy inference system, according to the range of the admittance parameters, the target force, and the current velocity of the surgical instrument.

3. The device according to claim 1, characterized in that, The current state of the surgical instruments is determined based on the reaction force acting on them.

4. The device according to claim 1, characterized in that, The current state includes one of the following: free state, cortical bone resection state, cancellous bone resection state, and regression state.

5. The device according to claim 1, characterized in that, The admittance parameters include virtual damping.

6. The device according to claim 1, characterized in that, Also includes: A force sensor is disposed between the robotic arm and the surgical instrument, and the force sensor is configured to detect the force applied to the surgical instrument.

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