Bone penetration judgment method

Abstract

The embodiment of the invention provides a bone penetration judgment method, which comprises the following steps of: acquiring drill bit stress in a drill bit advancing direction of an orthopedic surgical robot by utilizing a six-dimensional force sensor, and carrying out sliding window filtering processing with the filtering window size of n1 on the drill bit stress to obtain the drill bit stress subjected to the sliding window filtering processing; according to the drill bit stress subjected to sliding window filtering processing, the difference value between the drill bit stress in the current period and the drill bit stress at the interval of n2 periods with the current period and the maximum value of the drill bit stress in the whole bone drilling process are obtained, and according to the difference value between the drill bit stress in the current period and the drill bit stress before the n2 periods and the maximum value of the drill bit stress, the drill bit stress in the whole bone drilling process is obtained; and obtaining a bone penetration judgment equation, wherein the bone penetration judgment equation is used for judging whether the drill bit penetrates through the bone layer or not. Whether the drill bit penetrates through the bone layer or not can be judged when the orthopedic surgery robot conducts a surgery, and doctors are helped to improve the safety of the surgery.

Description

[Technical field]

[0001] The invention relates to a bone penetration judgment method, and belongs to the field of shutdown judgment optimization of orthopedic bone drilling surgical robots. [Background technology]

[0002] In the field of orthopedic bone drilling surgery, accurate bone penetration judgment is crucial to the success of the operation. With the continuous development of medical technology, orthopedic surgical robots have gradually become an important tool to improve surgical accuracy and efficiency. However, existing orthopedic surgical robots often have certain limitations when performing bone drilling operations. During the operation, the robot cannot accurately judge when the drill penetrates the bone surface, which may cause the drill to penetrate the bone surface too much, injuring blood vessels, nerves or muscles, and increasing surgical risks.

[0003] Therefore, how to accurately determine when the drill bit penetrates the bone surface during the robot bone drilling process is a technical problem that needs to be solved urgently in this field. [Summary of the invention]

[0004] In view of this, the present invention provides a bone penetration judgment method to judge the timing of drill penetration during the bone drilling process of an orthopedic surgical robot.

[0005] The present invention provides a method for determining bone penetration, comprising:

[0006] Using a six-dimensional force sensor to obtain the drill force of the orthopedic surgical robot in the forward direction of the drill, and performing a sliding window filtering process with a filter window size of n1 on the drill force to obtain the drill force after the sliding window filtering process;

[0007] According to the drill bit force after the sliding window filtering process, the difference between the drill bit force in the current cycle and the drill bit force in the interval n2 cycles from the current cycle is obtained;

[0008] According to the drill bit force after sliding window filtering, the maximum drill bit force in the whole bone drilling process is obtained;

[0009] According to the difference between the current drill bit force and the drill bit force n2 cycles ago and the maximum drill bit force, a bone penetration judgment equation is obtained, and the bone penetration judgment equation is used to judge whether the drill bit penetrates the bone layer.

[0010] In the above method, a six-dimensional force sensor is used to obtain the drill force of the orthopedic surgical robot in the forward direction of the drill, and the drill force is subjected to sliding window filtering with a filter window size of n1 to obtain the drill force after the sliding window filtering, including

[0011] The six-dimensional force sensor is placed between the mechanical arm and the drill of the orthopedic surgical robot, and the drill force in the forward direction of the drill of the orthopedic surgical robot is obtained and recorded as F. Then F is subjected to sliding window filtering, and the sliding window size is set to n1 to obtain the drill force F after the sliding window filtering in the current i-th cycle. i ′, the calculation method is:

[0012]

[0013] Among them, i is the current cycle, n1 is the sliding window size, F j is the drill bit force before the th cycle, for example, F j is the force on the drill bit at the current moment.

[0014] In the above method, according to the drill bit force after the sliding window filtering process, the difference between the drill bit force in the current cycle and the drill bit force in the interval n2 cycles from the current cycle is obtained, including

[0015] According to the drill bit force after sliding window filtering, the difference F between the drill bit force in the current i-th cycle and the drill bit force n2 cycles ago is obtained. i ″, the calculation method is:

[0016]

[0017] where F i ′ is the drill bit force after the sliding window filtering process in the i-th cycle, for example, F1 is the drill bit force after the sliding window filtering process in the first cycle.

[0018] In the above method, the maximum force of the drill bit during the whole bone drilling process is obtained according to the drill bit force after the sliding window filtering process, including

[0019] According to the drill bit force after sliding window filtering, the maximum drill bit force F′ in the whole bone drilling process is obtained. max , the calculation method is:

[0020]

[0021] Among them, F i ′ is the drill bit force after sliding window filtering in the i-th period.

[0022] In the above method, the bone penetration judgment equation is obtained according to the difference between the current drill bit force and the drill bit force n2 cycles ago and the maximum drill bit force. The bone penetration judgment equation is used to judge whether the drill bit penetrates the bone layer, including

[0023] According to the difference F between the current drill bit force and the drill bit force n2 cycles ago i ″ and the maximum drill force F′max Make a judgment:

[0024]

[0025] Where c is a self-set discriminant parameter, c∈(0,1);

[0026] Then the bone penetration judgment equation is obtained as follows:

[0027]

[0028] When y=-1, the drill bit has not penetrated the bone layer, and when y=1, the drill bit has penetrated the bone layer, completing the bone penetration judgment.

[0029] The technical solution provided by the embodiment of the present invention can make a penetration judgment in time when the orthopedic surgical robot drills through the bone, thereby improving the safety and accuracy of the surgery.

Brief Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It is obvious that the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creativity and labor.

[0031] Figure 1 is a flow chart of a bone penetration determination method provided by an embodiment of the present invention;

[0032] Figure 2 It is a technical roadmap of a bone penetration determination method provided by an embodiment of the present invention;

[0033] Figure 3 is an image of the calculation result of the bone penetration judgment equation provided in an embodiment of the present invention; [Specific embodiment]

[0034] In order to better understand the technical solution of the present invention, the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] It should be clear that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The present invention provides a method for determining bone penetration. Figure 1 , which is a flow chart of a bone penetration determination method provided by an example of the present invention, such as Figure 1 As shown, the method comprises the following steps:

[0037] Step 101, using a six-dimensional force sensor to obtain the drill force of the orthopedic surgical robot in the forward direction of the drill, and performing sliding window filtering processing with a filter window size of n1 on the drill force to obtain the drill force after the sliding window filtering processing.

[0038] The six-dimensional force sensor is placed between the mechanical arm and the drill of the orthopedic surgical robot, and the drill force in the forward direction of the drill of the orthopedic surgical robot is obtained and recorded as F. Then F is subjected to sliding window filtering, and the sliding window size is set to n1 to obtain the drill force F after the sliding window filtering in the current i-th cycle. i ′, the calculation method is:

[0039]

[0040] Among them, i is the current cycle, n1 is the sliding window size, F j is the drill force before the jth cycle, for example, F j is the force on the drill bit at the current moment.

[0041] Step 102, based on the drill bit force after the sliding window filtering process, obtain the difference between the drill bit force in the current cycle and the drill bit force in the period n2 interval from the current cycle.

[0042] According to the drill bit force after sliding window filtering, the difference F between the drill bit force in the current i-th cycle and the drill bit force n2 cycles ago is obtained. i ″, the calculation method is:

[0043]

[0044] where F i ′ is the drill bit force after the sliding window filtering process in the i-th cycle, for example, F1 is the drill bit force after the sliding window filtering process in the first cycle.

[0045] Step 103, obtaining the maximum force applied to the drill bit during the entire bone drilling process according to the drill bit force after the sliding window filtering process.

[0046] According to the drill bit force after sliding window filtering, the maximum drill bit force F′ in the whole bone drilling process is obtained. max , the calculation method is:

[0047]

[0048] Among them, F i ′ is the drill bit force after sliding window filtering in the i-th period.

[0049] Step 104, obtaining a bone penetration judgment equation based on the difference between the current drill bit force and the drill bit force n2 cycles ago and the maximum drill bit force, wherein the bone penetration judgment equation is used to judge whether the drill bit has penetrated the bone layer.

[0050] According to the difference F between the current drill bit force and the drill bit force n2 cycles ago i ″ and the maximum drill force F′ max Make a judgment:

[0051]

[0052] Where c is a self-set discriminant parameter, c∈(0,1);

[0053] Then the bone penetration judgment equation is obtained as follows:

[0054]

[0055] When y=-1, the drill bit has not penetrated the bone layer, and when y=1, the drill bit has penetrated the bone layer, completing the bone penetration judgment.

[0056] According to the above method provided by the embodiment of the present invention, a method for determining the shutdown of a robot in an orthopedic bone drilling operation is simulated.

[0057] In this embodiment, the UR10 collaborative robot arm is used to perform bone drilling simulation operations. Table 1 is an initial DH parameter table of the six-degree-of-freedom robot arm.

[0058] Table 1 UR-10 DH parameter table

[0059]

[0060] Among them, the joint number refers to the number of the six joints of the UR10 collaborative robot arm, θ refers to the joint angle, the unit is degree; d refers to the connecting rod offset, the unit is meter; a refers to the connecting rod length, the unit is meter; α refers to the connecting rod torsion angle, the unit is degree.

[0061] For example, the actual drill speed is 5000r / min and the drill feed speed is 0.1mm / s. Figure 2As shown in the flowchart, a six-dimensional force sensor is used to obtain the drill force of the orthopedic surgical robot in the forward direction of the drill, and the drill force is subjected to sliding window filtering with a filter window size of 5 to obtain the drill force after the sliding window filtering; according to the drill force after the sliding window filtering, the difference between the current drill force and the drill force 3 cycles ago and the maximum drill force during the entire bone drilling process are obtained, and the discrimination parameter c=0.6 is set according to the difference between the current drill force and the drill force 3 cycles ago and the maximum drill force, and then the bone penetration judgment equation is obtained, and the value of y is calculated to judge whether the drill has penetrated the bone layer. When y=-1, the drill has not penetrated the bone layer, and when y=1, the drill has penetrated the bone layer, completing the bone penetration judgment.

[0062] like Figure 3 As shown, the horizontal axis is time T and the vertical axis is the y value. The dotted line in the figure represents the y value at each moment during the bone drilling process. When time T = 10s, y = 1, at this time the drill bit has penetrated the bone layer.

[0063] The technical solution of the embodiment of the present invention has the following beneficial effects: using a six-dimensional force sensor to obtain the drill force in the forward direction of the drill of the orthopedic surgical robot, and performing sliding window filtering processing on the drill force with a filter window size of n1 to obtain the drill force after the sliding window filtering processing; according to the drill force after the sliding window filtering processing, the difference between the current drill force and the drill force n2 cycles ago and the maximum drill force during the entire bone drilling process are obtained, and the bone penetration judgment equation is obtained according to the difference between the current drill force and the drill force n2 cycles ago and the maximum drill force, and the bone penetration judgment equation is used to judge whether the drill has penetrated the bone layer. Through the present invention, it is possible to judge whether the drill has penetrated the bone layer when the orthopedic surgical robot is performing surgery, helping doctors improve the safety of the surgery.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0065] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A bone penetration determination method, characterized in that: The method comprises: Using a six-dimensional force sensor to obtain the drill force of the orthopedic surgical robot in the forward direction of the drill, and performing a sliding window filtering process with a filter window size of n1 on the drill force to obtain the drill force after the sliding window filtering process; According to the drill bit force after the sliding window filtering process, the difference between the drill bit force in the current cycle and the drill bit force in the interval n2 cycles from the current cycle is obtained; According to the drill bit force after sliding window filtering, the maximum drill bit force in the whole bone drilling process is obtained; According to the difference between the current drill bit force and the drill bit force n2 cycles ago and the maximum drill bit force, a bone penetration judgment equation is obtained, and the bone penetration judgment equation is used to judge whether the drill bit penetrates the bone layer.

2. The bone penetration determination method according to claim 1, characterized in that: The six-dimensional force sensor is used to obtain the drill force of the orthopedic surgical robot in the forward direction of the drill, and the drill force is subjected to sliding window filtering with a filter window size of n1 to obtain the drill force after the sliding window filtering. The specific process is as follows: The six-dimensional force sensor is placed between the mechanical arm and the drill of the orthopedic surgical robot, and the drill force in the forward direction of the drill of the orthopedic surgical robot is obtained and recorded as F. Then, F is subjected to sliding window filtering, and the sliding window size is set to n1 to obtain the drill force F after the sliding window filtering in the current i-th cycle. i ′, the calculation method is: Among them, i is the current cycle, n1 is the sliding window size, F j is the drill force before the jth cycle, for example, F j is the force on the drill bit at the current moment.

3. The bone penetration determination method according to claim 1, characterized in that: According to the drill bit force after sliding window filtering, the difference between the drill bit force in the current cycle and the drill bit force with an interval of n2 cycles from the current cycle is obtained. The specific process is as follows: According to the drill bit force after sliding window filtering, the difference F between the drill bit force in the current i-th cycle and the drill bit force n2 cycles ago is obtained. i ″, the calculation method is: Among them, F i ′ is the drill bit force after the sliding window filtering process in the i-th cycle, for example, F1 is the drill bit force after the sliding window filtering process in the first cycle.

4. The bone penetration determination method according to claim 1, characterized in that: According to the drill bit force after sliding window filtering, the maximum drill bit force during the entire bone drilling process is obtained. The specific process is as follows: According to the drill bit force after sliding window filtering, the maximum drill bit force F′ in the whole bone drilling process is obtained. max , the calculation method is: Among them, F i ′ is the drill bit force after sliding window filtering in the i-th period.

5. The bone penetration determination method according to claim 1, characterized in that: According to the difference between the current drill bit force and the drill bit force n2 cycles ago and the maximum drill bit force, a bone penetration judgment equation is obtained. The bone penetration judgment equation is used to judge whether the drill bit penetrates the bone layer. The specific process is as follows: According to the difference F between the current drill bit force and the drill bit force n2 cycles ago i ″ and the maximum drill force F′ max Make a judgment: Where c is a self-set discriminant parameter, c∈(0,1); Then the bone penetration judgment equation is obtained as follows: When y=-1, the drill bit has not penetrated the bone layer, and when y=1, the drill bit has penetrated the bone layer, completing the bone penetration judgment.

Images