A tibial cutter angle guide system and method

Abstract

The application discloses a tibia cutter deflection angle guiding system and method, relates to the technical field of medical operations, and collects static data of three positions of a tibia by three six-degree-of-freedom inertial sensors, processes the measurement results by a strapdown inertial navigation algorithm and a Kalman filtering algorithm, can track the position and posture of a bone and a surgical instrument, and guides the surgical instrument to accurately cut the tibia. The application can quickly and effectively measure the deflection angle of the posture of a tibia force line and a surgical instrument, assist in surgical incision planning, determine the best cutting plane of a cutting guide rail and the best position and posture of a prosthesis, and finally guide the cutting guide rail to the best position and angle.

Description

Technical Field

[0001] This invention relates to the field of medical surgical technology, specifically to a tibial cutter deflection guidance system and method. Background Technology

[0002] Modern knee replacement surgery underwent a revolutionary transformation in the late 1960s and early 1970s due to a series of improvements in prosthesis design. Although the design of knee replacement surgery has continued to improve during these years, the actual procedures and surgical instruments used in knee replacement surgery remain largely similar to the original methods and tools used in the early 1970s.

[0003] Currently, orthopedic surgeons still use traditional knee replacement surgery methods, which rely on complex mechanical devices for incision alignment. These devices are highly invasive. The most common method for referencing the mechanical axis of the knee joint is the use of an intramedullary nail. An intramedullary nail is an instrument used to align a tibial incision guide with the mechanical axis of the knee. Using an intramedullary nail requires drilling a guide hole in the femur, expanding the intramedullary canal, placing a guide rod within the medulla oblongata, and using the rod to remove excess bone, damaging the femoral bone marrow.

[0004] The use of intramedullary nails in knee replacement surgery has been shown to result in greater blood loss than the use of unconventional instruments. Furthermore, intramedullary nails are prone to misalignment. The intramedullary nail is aligned with the anatomical axis of the tibia that runs along the intramedullary canal. In some patients, the amount of misalignment is random and may exceed the standard deviation for various reasons, making it difficult to determine its specific mechanical axis using rods. During surgery, the intramedullary nail may also occasionally fracture within the femur, leading to serious complications. Additionally, patients with severe tibial deformities are not candidates for intramedullary nailing. Summary of the Invention

[0005] This invention addresses the problem that existing tibial cutting guides cannot determine the incision angle by providing a tibial cutting angle guidance system and method.

[0006] The present invention provides a tibial cutter deflection guidance system, comprising:

[0007] The tibial positioning rod is fixed to the tibia along the tibial force line via the first connector;

[0008] The measurement module includes a positioning rod reference IMU, a tibial reference IMU, and an osteotomy guide IMU. The positioning rod reference IMU is fixed on the tibial positioning rod, and the tibial reference IMU and the osteotomy guide IMU are fixed on the tibia through a second connector. The positioning rod reference IMU, the tibial reference IMU, and the osteotomy guide IMU are used to collect the positioning rod reference inertial data, the tibial reference inertial data, and the osteotomy guide inertial data of the tibia, respectively.

[0009] The data calculation module is used to obtain the attitude between each IMU through mathematical calculation based on the positioning rod reference inertial data, tibial reference inertial data and osteotomy guide inertial data of the tibia collected by the positioning rod reference IMU, tibial reference IMU and osteotomy guide IMU, and to calculate the coronal plane angle and sagittal plane angle.

[0010] An incision adjustment device is located on the osteotomy guide fixed to the tibia. The incision adjustment device is used to adjust the angle of the osteotomy guide according to the coronal and sagittal angles calculated by the data calculation module.

[0011] Furthermore, the tibial cutter deflection guidance system provided by the present invention also includes:

[0012] The data transmission module is connected to the positioning rod reference IMU, tibial reference IMU, osteotomy guide IMU and data processing module in the measurement module. The data transmission module is used to transmit the motion data collected by the positioning rod reference IMU, tibial reference IMU and osteotomy guide IMU in the measurement module to the data processing module.

[0013] Furthermore, the tibial cutter deflection guidance system provided by the present invention also includes:

[0014] The data display module is located on the osteotomy guide and connected to the data calculation module. The data display module is used to display the coronal and sagittal angles calculated by the data calculation module.

[0015] Furthermore, the tibial cutter deflection angle guidance method provided by the present invention includes the following steps:

[0016] The tibia was held still for 30 seconds in each of the three positions: abduction, adduction, and midline. The positioning rod reference IMU, tibial reference IMU, and osteotomy guide IMU were used to collect the positioning rod reference inertial data, tibial reference inertial data, and osteotomy guide inertial data of the tibia.

[0017] Based on quaternions, inertial navigation calculation, and Kalman filtering, the angle C between the positioning rod reference IMU and the tibial reference IMU is calculated in real time. T L The angle C between the osteotomy-guided IMU and the tibial reference IMU T O ;

[0018] The angle C between the real-time calculated osteotomy-guided IMU and the tibial reference IMU is... T O This is converted into the angle between the sagittal plane and the coronal plane, and the angle of the osteotomy guide is adjusted according to the angle between the sagittal plane and the coronal plane.

[0019] Furthermore, before acquiring the positioning rod reference inertial data, tibial reference inertial data, and osteotomy guide inertial data of the tibia using the positioning rod reference IMU, tibial reference IMU, and osteotomy guide IMU, the method further includes initializing the calculation parameters using the data calculation module, specifically including:

[0020] When the femur is at rest, the data processing module receives motion data collected by the positioning rod reference IMU, the tibial reference IMU, and the osteotomy guide IMU. It compensates for the zero bias of the triaxial gyroscope and triaxial accelerometer in the positioning rod reference IMU, the tibial reference IMU, and the osteotomy guide IMU, and at the same time receives position information to complete attitude, velocity, and position initialization.

[0021] Furthermore, before initializing the calculation parameters using the data calculation module, the procedure also includes installing surgical instruments, specifically including:

[0022] The tibial positioning rod is fixed to the tibia along the tibial force line via the first connector. The positioning rod reference IMU is installed onto the tibial positioning rod. The tibial reference IMU and osteotomy guide IMU are fixed to the tibia along the tibial positioning rod.

[0023] Furthermore, the real-time calculation of the angle between the positioning rod reference IMU and the tibial reference IMU... Angle between osteotomy-guided IMU and tibial reference IMU Specifically, it includes:

[0024] Using the two-vector attitude determination method to calculate For example, in the two states of tibial abduction and adduction, the gravity vector is denoted as V1 in the reference IMU coordinate system of the positioning rod. L , The gravity vector is denoted as V1 in the femoral reference IMU coordinate system. T , Construct auxiliary vectors

[0025] The formula for calculating the included angle is:

[0026]

[0027] Furthermore, the angle between the real-time calculated osteotomy-guided IMU and the tibial reference IMU is... Convert the angle between the sagittal plane and the coronal plane. Before adjusting the angle of the osteotomy guide according to the angle between the sagittal plane and the coronal plane, remove the tibial positioning rod, the positioning rod reference IMU and the first connector to prepare for osteotomy.

[0028] Furthermore, adjusting the angle of the osteotomy guide according to the sagittal plane angle and the coronal plane angle specifically includes:

[0029] The data display module on the osteotomy guide shows the sagittal and coronal plane angles. The angle of the osteotomy guide is adjusted according to the sagittal and coronal plane angles displayed on the data display module.

[0030] Compared with the prior art, the tibial cutter deflection guidance system and method provided by the present invention have the following advantages:

[0031] This invention uses three six-degree-of-freedom inertial sensors to collect static data from three positions on the tibia. The measurement results are processed using a strapdown inertial navigation algorithm and a Kalman filter algorithm to track the position and orientation of the bone and surgical instruments, guiding the instruments to accurately cut the tibia. This invention can quickly and effectively measure the tibial force line and the orientation angle of the surgical instruments, assisting in surgical incision planning, determining the optimal cutting plane of the cutting guide, and the optimal position and orientation of the prosthesis, ultimately guiding the cutting guide to its optimal position and angle. Attached Figure Description

[0032] Figure 1 A schematic diagram of the tibial cutter deflection guide system provided in an embodiment of the present invention;

[0033] Figure 2 This is a system block diagram of the tibial cutter deflection guide system provided in an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram illustrating the three positions of the tibia: abduction, adduction, and midline, as provided in an embodiment of the present invention.

[0035] In the figure: 1. Tibia, 2. Tibial positioning rod, 3. Positioning rod reference IMU, 4. Tibial reference IMU, 5. Osteotomy guide IMU, 6. Second connector, 7. First connector. Detailed Implementation

[0036] The following is in conjunction with the appendix Figure 1 -Appendix Figure 3 The following description further illustrates specific embodiments of the present invention. These embodiments are merely for illustrating the technical solutions of the present invention more clearly and should not be construed as limiting the scope of protection of the present invention.

[0037] Example 1: In view of the problem that the tibial cutting guide in the prior art cannot determine the incision angle, the present invention provides a tibial cutting guide deflection angle guidance system and method.

[0038] This invention provides a tibial cutter deflection guidance system, comprising: a tibial positioning rod 2, fixed to the tibia 1 along the tibial force line via a first connector 7; and a measurement module including a positioning rod reference IMU3, a tibial reference IMU4, and an osteotomy guide IMU5. The positioning rod reference IMU3 is fixed to the tibial positioning rod 2, and the tibial reference IMU4 and osteotomy guide IMU5 are fixed to the tibia 1 via a second connector 6. The positioning rod reference IMU3, tibial reference IMU4, and osteotomy guide IMU5 are respectively used to acquire the positioning rod reference inertial data of the tibia, the tibial reference IMU4, and the osteotomy guide IMU5. The system includes: reference inertial data and osteotomy guide inertial data; a data calculation module, used to obtain the attitude between each IMU through mathematical calculation based on the reference inertial data of the positioning rod IMU3, the tibial reference IMU4, and the osteotomy guide IMU5, and to calculate the coronal and sagittal angles; and an incision adjustment device, located on the osteotomy guide fixed on the tibial 1, used to adjust the angle of the osteotomy guide according to the coronal and sagittal angles calculated by the data calculation module.

[0039] In this embodiment, the tibial cutter deflection guidance system provided by the present invention further includes: a data transmission module, which is connected to the positioning rod reference IMU3, tibial reference IMU4, osteotomy guide IMU5 and data calculation module in the measurement module. The data transmission module is used to transmit the motion data collected by the positioning rod reference IMU3, tibial reference IMU4 and osteotomy guide IMU5 in the measurement module to the data calculation module.

[0040] In this embodiment, the tibial cutter deflection guidance system provided by the present invention further includes: a data display module, which is disposed on the osteotomy guide and connected to the data calculation module. The data display module is used to display the coronal angle and sagittal angle calculated by the data calculation module.

[0041] In this embodiment, the tibial cutter deflection angle guidance method provided by the present invention includes the following steps: The tibia 1 is held stationary for 30 seconds in three positions: abduction, adduction, and midline. Using the positioning rod reference IMU3, tibial reference IMU4, and osteotomy guide IMU5, the positioning rod reference inertial data, tibial reference inertial data, and osteotomy guide inertial data of the tibia 1 are collected. Based on quaternions, inertial navigation calculation, and Kalman filtering, the angle C between the positioning rod reference IMU3 and the tibial reference IMU4 is calculated in real time. T L The angle C between osteotomy guide IMU5 and tibial reference IMU4 T O The angle C between the real-time calculated osteotomy guide IMU5 and the tibial reference IMU4 is... T OThis is converted into the angle between the sagittal plane and the coronal plane, and the angle of the osteotomy guide is adjusted according to the angle between the sagittal plane and the coronal plane.

[0042] In this embodiment, before acquiring the positioning rod reference inertial data, tibial reference inertial data, and osteotomy guide inertial data of the tibia 1 using the positioning rod reference IMU3, tibial reference IMU4, and osteotomy guide IMU5, the data calculation module is used to initialize the calculation parameters. Specifically, in the femoral static state, the data calculation module receives the motion data acquired by the positioning rod reference IMU3, tibial reference IMU4, and osteotomy guide IMU5, compensates for the zero bias of the triaxial gyroscope and triaxial accelerometer in the positioning rod reference IMU3, tibial reference IMU4, and osteotomy guide IMU5, and simultaneously receives position information to complete the attitude, velocity, and position initialization.

[0043] In this embodiment, before initializing the calculation parameters using the data calculation module, the installation of surgical instruments is also included, specifically including: fixing the tibial positioning rod 2 to the tibia 1 along the tibial force line through the first connector 7, installing the positioning rod reference IMU3 onto the tibial positioning rod 2, and fixing the tibial reference IMU4 and osteotomy guide IMU5 to the tibia along the tibial positioning rod 2.

[0044] In this embodiment, the angle between the positioning rod reference IMU3 and the tibial reference IMU4 is calculated in real time. Angle between osteotomy guide IMU5 and tibial reference IMU4 Specifically, this includes: calculating using the two-vector attitude determination method. For example, in the two states of tibial abduction and adduction, the gravity vector is denoted as V1 in the reference IMU coordinate system of the positioning rod. L , The gravity vector is denoted as V1 in the femoral reference IMU coordinate system. T , Construct auxiliary vectors The formula for calculating the included angle is:

[0045]

[0046] In this embodiment, the angle between the real-time calculated osteotomy guide IMU5 and the tibial reference IMU4 is... Before converting the angle between the sagittal plane and the coronal plane into the angle between the sagittal plane and the coronal plane, and adjusting the angle of the osteotomy guide according to the angle between the sagittal plane and the coronal plane, remove the tibial positioning rod 2, the positioning rod reference IMU3 and the first connector 7 to prepare for osteotomy.

[0047] In this embodiment, adjusting the angle of the osteotomy guide according to the sagittal plane angle and the coronal plane angle specifically includes: displaying the sagittal plane angle and the coronal plane angle on the osteotomy guide using a data display module, and adjusting the angle of the osteotomy guide according to the sagittal plane angle and the coronal plane angle displayed by the data display module.

[0048] In summary, compared with the prior art, the tibial cutter deflection guidance system and method provided by the present invention have the following beneficial effects:

[0049] This invention uses three six-degree-of-freedom inertial sensors to collect static data from three positions on the tibia. The measurement results are processed using a strapdown inertial navigation algorithm and a Kalman filter algorithm to track the position and orientation of the bone and surgical instruments, guiding the instruments to accurately cut the tibia. This invention can quickly and effectively measure the tibial force line and the orientation angle of the surgical instruments, assisting in surgical incision planning, determining the optimal cutting plane of the cutting guide, and the optimal position and orientation of the prosthesis, ultimately guiding the cutting guide to its optimal position and angle.

[0050] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0051] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A tibial cutter deflection angle guidance system, characterized in that, include: The tibial positioning rod (2) is fixed to the tibia (1) along the tibial force line via the first connector (7); The measurement module includes a positioning rod reference IMU (3), a tibial reference IMU (4), and an osteotomy guide IMU (5). The positioning rod reference IMU (3) is fixed on the tibial positioning rod (2). The tibial reference IMU (4) and the osteotomy guide IMU (5) are fixed on the tibia (1) through a second connector (6). The positioning rod reference IMU (3), the tibial reference IMU (4), and the osteotomy guide IMU (5) are used to collect the positioning rod reference inertial data, the tibial reference inertial data, and the osteotomy guide inertial data of the tibia (1), respectively. The data calculation module is used to obtain the attitude between each IMU through mathematical calculation based on the positioning rod reference inertial data, tibial reference inertial data and osteotomy guide inertial data of the tibia (1) collected by the positioning rod reference IMU (3), the tibial reference IMU (4) and the osteotomy guide IMU (5), and to calculate the coronal plane angle and sagittal plane angle. An incision adjustment device is provided on the osteotomy guide fixed on the tibia (1). The incision adjustment device is used to adjust the angle of the osteotomy guide according to the coronal angle and sagittal angle calculated by the data calculation module.

2. The tibial cutter deflection guidance system as described in claim 1, characterized in that, Also includes: The data transmission module is connected to the positioning rod reference IMU (3), the tibial reference IMU (4), the osteotomy guide IMU (5) and the data processing module in the measurement module. The data transmission module is used to transmit the motion data collected by the positioning rod reference IMU (3), the tibial reference IMU (4) and the osteotomy guide IMU (5) in the measurement module to the data processing module.

3. The tibial cutter deflection guidance system as described in claim 1, characterized in that, Also includes: A data display module is mounted on the osteotomy guide and connected to the data calculation module. The data display module is used to display the coronal and sagittal angles calculated by the data calculation module.

4. A method for guiding the deflection angle of a tibial cutter based on the tibial cutter deflection angle guidance system according to any one of claims 1-3, characterized in that, Includes the following steps: The tibia (1) was held still for 30 seconds in each of the three positions of abduction, adduction, and midline. The positioning rod reference IMU (3), the tibia reference IMU (4), and the osteotomy guide IMU (5) were used to collect the positioning rod reference inertial data, the tibia reference inertial data, and the osteotomy guide inertial data of the tibia (1). Based on quaternions, inertial navigation calculation, and Kalman filtering, the angle between the positioning rod reference IMU (3) and the tibial reference IMU (4) is calculated in real time. The angle between the osteotomy guide IMU (5) and the tibial reference IMU (4) The angle between the real-time calculated osteotomy guide IMU (5) and the tibial reference IMU (4) is... The angle is converted into the sagittal plane angle and the coronal plane angle, and the angle of the osteotomy guide is adjusted according to the sagittal plane angle and the coronal plane angle.

5. The method for guiding the tibial cutter at an off-angle as described in claim 4, characterized in that, Before acquiring the positioning rod reference inertial data, tibial reference inertial data, and osteotomy guide inertial data of the tibia (1) using the positioning rod reference IMU (3), tibial reference IMU (4), and osteotomy guide IMU (5), the data calculation module is used to initialize the calculation parameters, specifically including: When the femur is at rest, the data processing module receives motion data collected by the positioning rod reference IMU (3), the tibial reference IMU (4) and the osteotomy guide IMU (5), compensates for the zero bias of the triaxial gyroscope and triaxial accelerometer in the positioning rod reference IMU (3), the tibial reference IMU (4) and the osteotomy guide IMU (5), and receives position information to complete attitude, velocity and position initialization.

6. The method for guiding the tibial cutter at an off-angle as described in claim 5, characterized in that, Before initializing the calculation parameters using the data calculation module, the procedure also includes installing surgical instruments, specifically including: The tibial positioning rod (2) is fixed to the tibia (1) along the tibial force line through the first connector (7). The positioning rod reference IMU (3) is installed on the tibial positioning rod (2). The tibial reference IMU (4) and osteotomy guide IMU (5) are fixed to the tibia along the tibial positioning rod (2).

7. The method for guiding the tibial cutter at an off-angle as described in claim 4, characterized in that, The angle between the real-time calculated positioning rod reference IMU (3) and the tibial reference IMU (4) The angle between the osteotomy guide IMU (5) and the tibial reference IMU (4) Specifically, it includes: Using the two-vector attitude determination method to calculate For example, in the two states of tibial abduction and adduction, the gravity vector is denoted as V1 in the reference IMU coordinate system of the positioning rod. L , The gravity vector is denoted as V1 in the femoral reference IMU coordinate system. T , Construct auxiliary vectors The formula for calculating the included angle is:

8. The method for guiding the tibial cutter at an off-angle as described in claim 4, characterized in that, The angle between the real-time calculated osteotomy guide IMU (5) and the tibial reference IMU (4) is... Before converting the angle between the sagittal plane and the coronal plane, and adjusting the angle of the osteotomy guide according to the angle between the sagittal plane and the coronal plane, remove the tibial positioning rod (2), the positioning rod reference IMU (3) and the first connector (7) to prepare for osteotomy.

9. The method for guiding the tibial cutter at an off-angle as described in claim 4, characterized in that, The adjustment of the osteotomy guide angle based on the sagittal and coronal plane angles specifically includes: The data display module on the osteotomy guide shows the sagittal and coronal plane angles. The angle of the osteotomy guide is adjusted according to the sagittal and coronal plane angles displayed on the data display module.

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