A navigation system for total hip replacement

Abstract

The present invention relates to the technical field of medical auxiliary treatment, and discloses a total hip replacement navigation system, comprising a reference reference device fixed on the pelvis of a patient in a supine position on an operating table; an acetabular cup impactor for adjusting the installation position of an acetabular cup prosthesis; a positioning device detachably mounted on the reference reference device and the acetabular cup impactor, and for measuring an initial anteversion angle and an initial valgus angle of the hip joint, as well as a real-time anteversion angle and a real-time valgus angle of the acetabular cup prosthesis during installation of the acetabular cup prosthesis; obtaining the dynamic anteversion angle and the dynamic valgus angle of the acetabular cup prosthesis by a quaternion attitude determination method according to the dynamic angular velocity of the acetabular cup prosthesis; compensating and correcting the real-time anteversion angle and the real-time valgus angle of the acetabular cup prosthesis according to the dynamic anteversion angle and the dynamic valgus angle of the acetabular cup prosthesis, so that the real-time anteversion angle and the real-time valgus angle of the acetabular cup prosthesis are consistent with the target anteversion angle and the target valgus angle, thereby achieving accurate positioning and installation of the acetabular cup prosthesis.

Description

Technical Field

[0001] The present invention relates to the technical field of medical auxiliary treatment, and in particular to a total hip replacement navigation system. Background Art

[0002] With the aging population, the number of artificial joint replacement surgeries has increased. Total hip replacement is widely used for osteoarthritis, femoral head necrosis, partial hip fractures, rheumatoid arthritis, traumatic arthritis, ankylosing spondylitis, etc.

[0003] A total hip joint consists of an artificial acetabulum and an artificial femoral head. Traditionally, total hip replacements involve preoperative marking of the patient's hip joint based on X-rays or CT / MRI images before surgery. This method relies on experience and, due to individual patient characteristics, can make it difficult to accurately position and place the acetabular cup. Improper placement of the acetabular cup during total hip replacement surgery can lead to loosening and ultimately complications such as surgical failure, prosthesis trauma, limited range of motion, excessive liner wear, and osteolysis. These complications can necessitate revision surgery, resulting in secondary harm to the patient and significantly increased healthcare costs.

[0004] In order to solve the problem of acetabular cup positioning accuracy, many surgical navigation methods and instruments have emerged in recent years. They can be summarized as follows:

[0005] 0. With the help of CT / MRI equipment method, this method is based on CT / MRI imaging data. During the planning of the surgical plan, the patient needs to undergo multiple CT / MRI examinations according to the stages of the operation, thereby increasing the operation time; errors that affect the data conversion of the surgical implementation plan will cause acetabular cup positioning errors; multiple CT / MRIs will cause significant radiation risks to the patient.

[0006] 1. Popular surgical robotics. Surgical robots have been successfully used in total hip replacements both domestically and internationally, achieving good results. However, robotics have some problems: (1) They place high demands on surgeons. Doctors must be proficient in operating the equipment before using it, and must deal with problems caused by improper use of the equipment during surgery. (2) Robots are too expensive for ordinary patients, and patients usually choose simpler and more cost-effective methods, which results in a low rate of use of surgical robots. (3) Surgical robots also have high maintenance costs.

[0007] 2. Mechanical positioning is to use special mechanical tools to determine the patient's corresponding anteversion and valgus angles before surgery, and to know the total hip replacement surgery. The problems with this method are: (1) it cannot meet the personalized requirements of different patients; (2) it is difficult to bend to ensure the accuracy of acetabular cup positioning under dynamic surgical conditions; (3) the mechanical structure of the tool positioning will deform as the use time increases, and the accuracy of the tool is difficult to guarantee.

[0008] The present invention provides a total hip replacement navigation system for solving the problems of high installation cost, large error and low precision of acetabular cup prosthesis in the prior art. Summary of the Invention

[0009] The present invention provides a total hip replacement navigation system, which solves the problems of high installation cost, large error and low precision of acetabular cup prosthesis in the prior art, reduces the installation cost of acetabular cup prosthesis and improves the installation precision of acetabular cup prosthesis.

[0010] The present invention provides a total hip replacement navigation system, comprising a reference device fixed to the pelvis of a patient in a supine position on an operating table; an acetabular cup impactor for adjusting the installation position of an acetabular cup prosthesis; and a positioning device detachably mounted on the reference device and the acetabular cup impactor in a time-sharing manner. The positioning device comprises:

[0011] A data acquisition module is used to obtain the initial acceleration of the patient's hip joint; and to obtain the real-time acceleration and dynamic angular velocity of the acetabular cup prosthesis during the installation process of the acetabular cup prosthesis;

[0012] A dual-vector positioning module is used to obtain the initial anteversion angle and initial valgus angle of the hip joint through the dual-vector positioning method based on the initial acceleration of the hip joint; and is used to obtain the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis during the installation process of the acetabular cup prosthesis through the dual-vector positioning method based on the real-time acceleration of the acetabular cup prosthesis;

[0013] A quaternion posture determination module is used to obtain the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis through the quaternion posture determination method according to the dynamic angular velocity of the acetabular cup prosthesis;

[0014] The data processing module is used to compensate and correct the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis according to the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis; compare the corrected real-time anteversion angle and real-time valgus angle with the target anteversion angle and target valgus angle. When the corrected real-time anteversion angle and real-time valgus angle are inconsistent with the target anteversion angle and target valgus angle, as the striking direction of the external acetabular cup impactor is adjusted, the corrected real-time anteversion angle and real-time valgus angle approach the target anteversion angle and target valgus angle through continuous iteration, so that the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are consistent with the target anteversion angle and target valgus angle, thereby realizing the positioning and installation of the acetabular cup prosthesis.

[0015] According to the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis, the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are compensated and corrected by a weighted fusion method.

[0016] The above-mentioned target anteversion angle and target valgus angle are determined based on the initial anteversion angle and initial valgus angle of the hip joint and the patient's height, weight and lesion location. The positioning device also includes: a display unit, which is connected to the data processing module and sends the target anteversion angle and target valgus angle to the data processing module.

[0017] The above data acquisition module includes:

[0018] A triaxial accelerometer is used to measure the initial acceleration of the hip joint and the dynamic acceleration of the acetabular cup prosthesis during the installation process of the acetabular cup prosthesis;

[0019] A three-axis gyroscope is used to measure the dynamic angular velocity during the installation of the acetabular cup prosthesis.

[0020] The positioning device is preoperatively installed on the left or right side of the reference device according to the patient's lesion location to perform initial alignment and obtain the initial anteversion angle and initial valgus angle of the hip joint;

[0021] After the initial alignment is completed, the positioning device is removed from the reference datum device and installed on the acetabular cup impactor.

[0022] A total hip replacement navigation system, the use method of which comprises the following steps:

[0023] A reference device is mounted on the pelvis of a supine patient, and a positioning device is mounted on the reference device for initial alignment to detect the initial acceleration of the hip joint; based on the initial acceleration of the hip joint, the initial anteversion angle and initial valgus angle of the hip joint are obtained using a dual-vector positioning method; and based on the initial anteversion angle and initial valgus angle of the hip joint, the target anteversion angle and target valgus angle are determined;

[0024] After the initial alignment is completed, the positioning device is removed from the reference device and installed on the acetabular cup impactor to detect the real-time acceleration information and dynamic angular velocity of the acetabular cup prosthesis;

[0025] According to the real-time acceleration of the acetabular cup prosthesis, the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are obtained by the double-vector positioning method;

[0026] According to the dynamic angular velocity of the acetabular cup prosthesis when the acetabular cup striker is struck to adjust the installation position of the acetabular cup prosthesis, the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis are obtained by the quaternion posture determination method;

[0027] According to the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis, the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are compensated and corrected; the corrected real-time anteversion angle and real-time valgus angle are compared with the target anteversion angle and target valgus angle. When the corrected real-time anteversion angle and real-time valgus angle are inconsistent with the target anteversion angle and target valgus angle, as the striking direction of the external acetabular cup impactor is adjusted, the corrected real-time anteversion angle and real-time valgus angle approach the target anteversion angle and target valgus angle through continuous iteration, so that the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are consistent with the target anteversion angle and target valgus angle, thereby achieving the positioning and installation of the acetabular cup prosthesis.

[0028] According to the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis, the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are compensated and corrected by a weighted fusion method.

[0029] The target anteversion angle and target valgus angle are determined based on the initial anteversion angle and initial valgus angle of the hip joint as well as the patient's height, weight and lesion location.

[0030] The specific method of obtaining the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis by the above-mentioned dual-vector positioning method includes:

[0031] There are two rectangular coordinate systems in three-dimensional space Department and System, n is the pelvic coordinate system, b is the acetabular cup prosthesis coordinate system, and two non-collinear reference vectors are known. and , the projection coordinates in the two coordinate systems are recorded as , and , , solved by known projection coordinates Department and The azimuth relationship between the two coordinate systems is described by the direction cosine matrix, which is recorded as , reference vector and exist Department and The following conversion relationship exists under the system:

[0032] (1)

[0033] (2)

[0034] In order to solve , and then construct a vector equation by cross-multiplying equation (1) by equation (2) to obtain the vector equation:

[0035] (3)

[0036] According to formula (1), formula (2) and formula (3), the matrix form is as follows:

[0037]

[0038] in, and for and The coordinate representation in the n system is: and for and The coordinate representation in the b system is: They are and Coordinate representation of the cross product vector in n-system and b-system;

[0039] The attitude angle from system b to system n is obtained by equation (4), which is called dual-vector attitude determination.

[0040] The real-time anteversion and valgus angles of the acetabular cup prosthesis are obtained by using the dual-vector positioning method:

[0041] ; (5)

[0042] In formula (5) It is the real-time anteversion angle and real-time valgus angle, are the accelerations of the x-axis, y-axis, and z-axis respectively.

[0043] The specific method for obtaining the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis by the quaternion posture determination method based on the dynamic angular velocity of the acetabular cup prosthesis when the acetabular cup striker is struck includes:

[0044] Assume that the space is a vector Expressed in quaternion form:

[0045]

[0046] in, is the real part, 、 and are the coefficients of the imaginary parts i, j and k respectively,

[0047] Vector Rotate an angle to another coordinate system The vector representation is: , so the transformation relationship between the two coordinate systems is:

[0048]

[0049] in: ;

[0050] ;

[0051] ;

[0052] In this system, when the pelvic coordinate system is converted to the acetabular cup prosthesis coordinate system using quaternion, the transformation matrix is:

[0053]

[0054] The quaternion differential equation is expressed as:

[0055]

[0056] In formula (9) , is the angular velocity of the acetabular cup prosthesis coordinate system relative to the pelvic coordinate system, is the angular velocity in the x direction in the acetabular cup prosthesis coordinate system, is the angular velocity in the y direction of the acetabular cup prosthesis coordinate system, is the angular velocity in the z direction of the acetabular cup prosthesis coordinate system, from which the dynamic anteversion angle of the acetabular cup prosthesis is calculated and dynamic valgus angle They are:

[0057]

[0058] .

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] The present invention obtains the initial anteversion angle and initial valgus angle of the hip joint and the real-time acceleration of the acetabular cup prosthesis through a dual-vector positioning method based on the patient's preoperative initial acceleration of the hip joint and the real-time acceleration of the acetabular cup prosthesis. When the acetabular cup striker is struck, the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis are obtained through a quaternion positioning method based on the dynamic angular velocity of the acetabular cup prosthesis. Based on the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis, the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are compensated and corrected through weighted fusion, so that the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are consistent with the target anteversion angle and target valgus angle, thereby realizing accurate positioning and installation of the acetabular cup prosthesis. The present invention provides real-time navigation, does not require multiple CT / MRI imaging data, and will not cause secondary harm to the patient. The present invention lays a solid foundation for minimally invasive total hip replacement surgery.

[0061] The present invention fully considers the dynamic environment and interference during the operation, overcomes the interference caused by the vibration and impact of the acetabular cup impactor during the installation of the acetabular cup prosthesis, improves the accuracy of the acetabular cup prosthesis installation, and is of great help to the patient's postoperative recovery.

[0062] The present invention performs personalized surgery based on the patient's characteristics, greatly improving the success rate of the surgery; the device of the present invention is simple to set up, easy to operate, and requires little experience from the doctor; the present invention is suitable for widespread promotion and use in qualified hospitals; the present invention is a key device for the currently popular DAA minimally invasive surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 This is a schematic diagram of the simulated structure of the IAD in the total hip replacement navigation system provided by the present invention.

[0064] Figure 2 This is a schematic structural diagram of an acetabular cup impactor in a total hip replacement navigation system provided by the present invention.

[0065] Figure 3 This is a principle block diagram of the AOD in the total hip replacement navigation system provided by the present invention.

[0066] Figure 4 This is a principle block diagram of posture solution in a total hip replacement navigation system provided by the present invention.

[0067] Figure 5 This is a principle block diagram of the acetabular cup impactor installed in the total hip replacement navigation system provided by the present invention.

[0068] Figure 6 This is a structural schematic diagram of the CRD in the total hip replacement navigation system provided by the present invention.

[0069] Figure 7 This is a structural schematic diagram of the IAD in the total hip replacement navigation system provided by the present invention.

[0070] Figure 8 The present invention provides a flowchart of a total hip replacement navigation system and its usage method.

[0071] Description of reference numerals:

[0072] 1-CRD, 2-AOD, 3-Operating table, 4-Patient, 5-Pelvis, 6-Acetabular cup prosthesis, 7-Acetabular cup impactor. DETAILED DESCRIPTION

[0073] The following is combined with Figure 1-8 , a specific embodiment of the present invention is described in detail, but it should be understood that the protection scope of the present invention is not limited by the specific embodiment.

[0074] In order to solve the problem of accurate positioning of acetabular cup prosthesis, many surgical navigation methods and instruments have emerged in recent years. They can be summarized as follows:

[0075] 1. With the help of CT / MRI equipment method, this method is based on CT / MRI imaging data. During the planning of the surgical plan, the patient needs to undergo multiple CT / MRI examinations according to the stages of the operation, thereby increasing the operation time; errors that affect the data conversion and surgical implementation plan agent will cause acetabular cup positioning errors; multiple CT / MRIs will cause potential radiation risks to patients.

[0076] 2. Popular surgical robotics. Surgical robots have been successfully used in total hip replacements both domestically and internationally, achieving good results. However, robotics have some problems: (1) They place high demands on surgeons. Doctors must be proficient in operating the equipment before using it, and must deal with problems caused by improper use of the equipment during surgery. (2) Robots are too expensive for ordinary patients, and patients usually choose simpler and more cost-effective methods, which leads to a low utilization rate of surgical robots. (3) The maintenance costs of surgical robots are high.

[0077] 3. Mechanical positioning is to use special mechanical tools to determine the patient's corresponding anteversion and valgus angles before surgery, and to know the total hip replacement surgery. The problems with this method are: (1) it cannot meet the personalized requirements of different patients; (2) it is difficult to bend to ensure the accuracy of acetabular cup positioning under dynamic surgical conditions; (3) the mechanical structure of the tool positioning will deform as the use time increases, and the accuracy of the tool is difficult to guarantee.

[0078] In order to solve the above problems, the present invention discloses a total hip replacement navigation system and method, the navigation system includes a reference reference device, which is fixed on the pelvis of a patient in a supine position on an operating table; an acetabular cup impactor, which is used to adjust the installation position of the acetabular cup prosthesis; a positioning device, which is detachably installed on the reference reference device and the acetabular cup impactor in a time-sharing manner, wherein the positioning device includes: a data acquisition module, which is used to obtain the initial acceleration of the patient's hip joint; and a module for obtaining the real-time acceleration of the acetabular cup prosthesis and the dynamic angular velocity of the acetabular cup prosthesis during the installation of the acetabular cup prosthesis; a dual-vector positioning module, which is used to obtain the initial anteversion angle and initial valgus angle of the hip joint through a dual-vector positioning method based on the initial acceleration of the hip joint; and a module for obtaining the real-time anteversion angle of the acetabular cup prosthesis during the installation of the acetabular cup prosthesis through a dual-vector positioning method based on the real-time acceleration of the acetabular cup prosthesis. inclination angle, real-time valgus angle; a quaternion attitude determination module, used to obtain the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis through the quaternion attitude determination method according to the dynamic angular velocity of the acetabular cup prosthesis; a data processing module, used to compensate and correct the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis according to the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis; the corrected real-time anteversion angle and real-time valgus angle are compared with the target anteversion angle and target valgus angle. When the corrected real-time anteversion angle and real-time valgus angle are inconsistent with the target anteversion angle and target valgus angle, as the striking direction of the external acetabular cup impactor is adjusted, the corrected real-time anteversion angle and real-time valgus angle approach the target anteversion angle and target valgus angle through continuous iteration, so that the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are consistent with the target anteversion angle and target valgus angle, thereby realizing the positioning and installation of the acetabular cup prosthesis.

[0079] According to the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis, the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are compensated and corrected by a weighted fusion method.

[0080] The target anteversion angle and target valgus angle for installation of the acetabular cup prosthesis are set according to the initial anteversion angle and initial valgus angle of the hip joint and the patient's height, weight and lesion location; the display unit is used to set the target anteversion angle and target valgus angle for installation of the acetabular cup prosthesis, and to display the patient's basic information, surgical planning information, initial acceleration of the hip joint, acceleration during the installation process of the acetabular cup prosthesis, angular velocity of the acetabular cup prosthesis, real-time anteversion angle and real-time valgus angle data.

[0081] The above-mentioned target anteversion angle and target valgus angle are set according to the provisions of the medical safety angle.

[0082] The surgical planning information includes the surgical object, such as the left leg or the right leg, and the surgical opening location.

[0083] The data acquisition module includes: a three-axis accelerometer for measuring the initial acceleration of the hip joint and the dynamic acceleration during the installation of the acetabular cup prosthesis; and a three-axis gyroscope for measuring the dynamic angular velocity during the installation of the acetabular cup prosthesis.

[0084] The three-axis accelerometer and the three-axis gyroscope constitute a three-degree-of-freedom inertial measurement unit (IMU).

[0085] It also includes a reference reference device, which is fixed on the pelvis of a patient in a supine position on the operating bed, and the positioning device is arranged on the reference reference device; the positioning device is installed on the left or right side of the reference reference device according to the location of the patient's lesion before surgery, and performs initial alignment to obtain the initial anteversion angle and initial valgus angle of the hip joint. After completing the initial alignment, the positioning device is removed from the reference reference device and installed on the acetabular cup impactor to navigate the acetabular cup prosthesis and realize the installation of the acetabular cup prosthesis in the acetabulum socket of the patient's pelvis.

[0086] The Total Hip Arthroplasty Navigation System, also known as the Total Hip Arthroplasty Accurate Navigation Device (THAAND), is a new intelligent technology method proposed to address the problems existing in the current total hip arthroplasty navigation methods. Figure 1 As shown, THAAND consists of an Accurate Orienting Device (AOD) and a Calibration Reference Device (CRD). AOD 2 and CRD 1 form the Initial Alignment Device (IAD). THAAND utilizes inertial navigation technology. The AOD, comprised of a 3-degree-of-freedom Inertial Measurement Unit (IMU), is mounted on an acetabular impactor for dynamic measurement. Using dual-vector positioning, the system calculates the real-time anteversion and valgus angles of the dynamic acetabular cup prosthesis in real time. Quaternion positioning is used to compensate for dynamic errors during installation, and real-time navigation is performed during surgery to ensure accurate positioning and installation of the acetabular cup prosthesis.

[0087] The present invention installs a reference reference device on the pelvis 5 of a supine patient 4 on an operating table 3, installs a positioning device on the reference reference device, powers on for initial alignment, and uses a three-axis accelerometer to detect the initial acceleration of the hip joint; based on the initial acceleration of the hip joint, the initial anteversion angle and initial valgus angle of the hip joint are calculated using a dual-vector attitude determination method; and based on the initial anteversion angle and initial valgus angle of the hip joint, the target anteversion angle and target valgus angle for installation of the acetabular cup prosthesis are set according to the initial anteversion angle and initial valgus angle of the hip joint as well as the patient's height, weight, and lesion location.

[0088] By removing the positioning device from the reference reference device and installing it on the acetabular cup impactor 7, a three-axis accelerometer is used to detect the dynamic acceleration of the acetabular cup prosthesis 6 during the installation process; based on the dynamic acceleration of the acetabular cup prosthesis during the installation process, the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are calculated using the dual-vector attitude determination method.

[0089] The dynamic angular velocity of the acetabular cup prosthesis when the acetabular cup striker is struck is detected by a three-axis gyroscope. Based on the dynamic angular velocity of the acetabular cup prosthesis when the acetabular cup striker is struck, the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis are obtained by the quaternion attitude determination method. Based on the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis, the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are compensated and corrected by weighted fusion to obtain the corrected real-time anteversion angle and real-time valgus angle when the acetabular cup prosthesis is installed.

[0090] The corrected real-time anteversion angle and real-time valgus angle are compared with the target anteversion angle and target valgus angle. When the real-time anteversion angle and real-time valgus angle are inconsistent with the target anteversion angle and target valgus angle, the striking direction of the acetabular cup striker is adjusted. The corrected real-time anteversion angle and real-time valgus angle approach the target anteversion angle and target valgus angle through continuous iteration, so that the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are consistent with the target anteversion angle and target valgus angle, so that the acetabular cup prosthesis can be installed in the acetabulum of the patient's pelvis. Figure 5 shown.

[0091] The THAAND system and method have the following advantages: (1) The system has different surgical plans and parameter settings for different patients, demonstrating personalized design; (2) The system fully considers the dynamic environment and interference during the operation to ensure the positioning accuracy of the acetabular cup prosthesis; (3) The system is simple in design, easy to operate, and quick to calibrate, with low requirements for doctors; (4) The system provides real-time navigation and does not require multiple CT / MRI imaging data, which will not cause secondary harm to the patient; (5) The system is an intelligent device with a wide range of applications. In particular, the AOD is a single-use device, and the CRD equipment has very low maintenance costs; (6) The system has laid a solid foundation for minimally invasive DAA (direct anterior access) total hip replacement surgery.

[0092] Coordinate system definition:

[0093] (1)O n X n Y n Z n is the pelvic coordinate system. In hip replacement surgery, the pelvic coordinate system is consistent with the geographic coordinate system. n The axis pointing in the abduction direction along the coronal plane is positive, n The axis pointing toward the head along the coronal plane is positive, and Zn Conforms to the right-hand rule.

[0094] (2)O h X h Y h Z h is the hip joint coordinate system, the Xh axis is positive when it points to the abduction direction along the coronal plane, the Yh axis is positive when it points to the head along the coronal plane, and the Zh axis conforms to the right-hand rule.

[0095] (3) O b X b Y b Z b It is the acetabular cup prosthesis coordinate system, which is the action coordinate system fixedly connected to the acetabular cup impactor. Its static state is consistent with the hip joint coordinate system.

[0096] (3) Double vector attitude determination method:

[0097] There are two rectangular coordinate systems in three-dimensional space Department and System, n is the pelvic coordinate system, b is the acetabular cup prosthesis coordinate system, and two non-collinear reference vectors are known. and , the projection coordinates in the two coordinates are recorded as , and , , solved by known projection coordinates The orientation relationship between the two coordinate systems is described by the direction cosine matrix (attitude matrix), which is recorded as Obviously, the two vector coordinates have the following conversion relationship in different coordinate systems:

[0098] (1)

[0099] (2)

[0100] The above two equations contain 6 scalar equations in total. , and then construct a vector equation (including 3 scalar equations) by cross-multiplying equation (1) by equation (2) to obtain the vector equation

[0101] (3)

[0102] Write the three vector expressions in matrix form

[0103]

[0104] The attitude angle from system b to system n can be calculated by equation (4), which is called dual-vector attitude determination.

[0105] in, and for and The coordinate representation in the n system is: and for and The coordinate representation in the b system is: They are and The coordinate representation of the cross product vector in the n-system and the b-system.

[0106] THAAND uses a dual-vector positioning method to obtain the real-time anteversion and valgus angles of the acetabular cup prosthesis:

[0107] ; (5)

[0108] In the formula It is the real-time anteversion angle and real-time valgus angle, are the accelerations of the x-axis, y-axis, and z-axis respectively.

[0109] The calculation method of the initial anteversion angle and initial valgus angle of the hip joint is the same as above, except that the pelvic coordinate system and the hip joint coordinate system are used.

[0110] (2) Quaternion posture determination method

[0111] Assume that the space is a vector Expressed in quaternion form:

[0112]

[0113] in, is the real part, 、 and are the coefficients of the imaginary parts i, j and k respectively,

[0114] Vector Rotate an angle to another coordinate system The vector representation is: , so the transformation relationship between the two coordinate systems is

[0115]

[0116] in:

[0117]

[0118]

[0119]

[0120] In this system, when the pelvic coordinate system is converted to the acetabular cup prosthesis coordinate system using quaternion, its direction cosine matrix is:

[0121]

[0122] The direction cosine matrix parameters are expressed as quaternion differential equations:

[0123]

[0124] in , is the angular velocity of the acetabular cup prosthesis coordinate system relative to the pelvic coordinate system, is the angular velocity in the x direction in the acetabular cup prosthesis coordinate system, is the angular velocity in the y direction of the acetabular cup prosthesis coordinate system, is the angular velocity in the z direction of the acetabular cup prosthesis coordinate system, from which the dynamic anteversion angle of the acetabular cup prosthesis is calculated and dynamic valgus angle They are:

[0125]

[0126] .

[0127] (3) Weighted fusion method

[0128] (12)

[0129] (13)

[0130] in, is the anteversion angle of the acetabular cup prosthesis, is the valgus angle of the acetabular cup prosthesis; , They are the real-time anteversion angle and real-time valgus angle of the acetabular cup obtained by dual-vector positioning; , The dynamic anteversion and valgus angles of the acetabular cup obtained for quaternion pose determination; is the weighting coefficient.

[0131] Dynamic interference suppression

[0132] Once the acetabular cup prosthesis is positioned, it is installed in the acetabular socket using a striking device. This process generates impact and vibration, which can introduce additional errors to the attitude angle. To eliminate this interference, the system uses a gyroscope to detect the angular velocity of the acetabular cup prosthesis and, using quaternion methods, calculates the dynamic attitude angle of the acetabular cup prosthesis and compensates for the dual-vector attitude determination results.

[0133] The RCD consists of three adjustable positioning columns and an adjustable stand. Figure 6 The RCD includes three height-adjustable positioning columns, two of which are fixed on either side of the patient's pelvis and are located in the same straight line, and the other is fixed between the patient's legs;

[0134] The platform is adjustable in length and is arranged on three positioning columns. The length can be adjusted according to the patient's body shape and position. The positioning device is arranged on the mounting frame.

[0135] IAD is composed of RCD and AOD. Figure 1 and Figure 7 Before the operation, according to the patient's supine position on the operating table, the RCD is stably placed on the operating table as shown in Figure 7, keeping the patient and the RCD closely connected and motionless.

[0136] Working principle and process

[0137] (1) Press CRD Figure 1 The AOD is stably mounted on the pelvis of a supine patient. According to the patient's surgical plan, the AOD is mounted on the reference device (forming the IAD) and the device is powered on for a few seconds for initial alignment. Using the system accelerometer information, the attitude angle between the hip joint coordinate system Ohxhyhzh and the pelvic coordinate system Onxnynzn is calculated using the dual-vector method to determine the initial anteversion angle of the patient's hip joint. and initial valgus angle .

[0138] (2) Based on the initial anteversion angle of the hip joint and initial valgus angle The target anteversion angle of the acetabular cup prosthesis is set on the AOD according to the patient's height, weight and lesion location. and target valgus angle .

[0139] (3) Remove the AOD from the CRD and stably install it on the acetabular cup impactor. Place the acetabular cup prosthesis on the edge of the patient's acetabulum and install it on the front end of the acetabular cup impactor. Adjust the handle of the acetabular cup impactor and adjust the target anteversion angle under the guidance of the AOD. and target valgus angle At different positions, dual-vector attitude solution is performed through accelerometer information, and search, tracking and locking are implemented. After the target position is locked, the navigation doctor installs the acetabular cup prosthesis. During the installation of the acetabular cup prosthesis, the impact and vibration generated by hitting the acetabular cup impactor will cause deviation in the attitude solution. The system introduces a three-axis gyroscope to measure angular velocity information, performs dynamic attitude solution through the quaternion algorithm, and compensates and corrects the dual-vector solution results. The THAAND process is shown in Figure 8.

[0140] The present invention relates to the field of medical auxiliary treatment technology and discloses a precise navigation system for total hip replacement.

[0141] The navigation system includes a reference device, a positioning device and an acetabular cup impactor.

[0142] The reference device is fixedly placed on the patient's pelvis to measure the initial state of the patient's hip joint before surgery;

[0143] The positioning device is composed of an inertial sensor unit and a display unit. 1. The anteversion angle and valgus angle of the patient's hip joint before surgery are determined by dual-vector positioning using its three-axis accelerometer information. 2. When installing the acetabular cup prosthesis, the positioning device is connected to the acetabular cup prosthesis impactor. The anteversion angle and valgus angle of the acetabular cup prosthesis are solved in real time using the dual-vector method based on its accelerometer information. At the same time, the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis under the vibration and impact interference of the impactor are solved using quaternions based on the three-axis gyroscope information, and the results are used to compensate and correct the angles solved using the dual-vector solution using the accelerometer information; the acetabular cup impactor is a tool for installing the acetabular cup prosthesis, and the accurate installation of the acetabular cup prosthesis is achieved under the navigation of the precise positioning device, such as Figure 1-Figure 4 shown.

[0144] The present invention can formulate different surgical plans and parameter settings according to different patients, showing personalized design; the present invention fully considers the dynamic environment and interference during the operation to ensure the positioning accuracy of the acetabular cup prosthesis; the present invention has a simple design, easy operation, fast calibration, and low requirements for doctors; the present invention provides real-time navigation and does not require multiple CT / MRI imaging data, so it will not cause secondary harm to the patient; the present invention is an intelligent device with a wide range of uses; the AOD of the present invention is single-use, and the maintenance cost of the CRD equipment is very low; the present invention lays a solid foundation for minimally invasive DAA (direct anterior access) total hip replacement surgery.

[0145] The present invention improves the positioning accuracy of the acetabular cup prosthesis, which is of great help to the patient's postoperative recovery; the present invention performs personalized surgery based on the patient's characteristics, which greatly improves the success rate of the surgery; the device of the present invention is simple to set up, easy to operate, and has low requirements for the doctor's experience accumulation; the present invention is suitable for widespread promotion and use in qualified hospitals; the present invention is a key device for the currently popular DAA minimally invasive surgery.

[0146] The above disclosures are only a few specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the scope of protection of the present invention.

Claims

1. A total hip replacement navigation system, characterized in that: It includes a reference device fixed on the pelvis of a patient in a supine position on an operating table; an acetabular cup impactor for adjusting the installation position of the acetabular cup prosthesis; A positioning device is detachably mounted on the reference device and the acetabular cup impactor in a time-sharing manner, wherein the positioning device comprises: A data acquisition module is used to obtain the initial acceleration of the patient's hip joint; and to obtain the real-time acceleration and dynamic angular velocity of the acetabular cup prosthesis during the installation process of the acetabular cup prosthesis; A dual-vector positioning module is used to obtain the initial anteversion angle and initial valgus angle of the hip joint through the dual-vector positioning method based on the initial acceleration of the hip joint; and is used to obtain the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis during the installation process of the acetabular cup prosthesis through the dual-vector positioning method based on the real-time acceleration of the acetabular cup prosthesis; A quaternion posture determination module is used to obtain the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis through the quaternion posture determination method according to the dynamic angular velocity of the acetabular cup prosthesis; The data processing module is used to compensate and correct the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis according to the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis; compare the corrected real-time anteversion angle and real-time valgus angle with the target anteversion angle and target valgus angle. When the corrected real-time anteversion angle and real-time valgus angle are inconsistent with the target anteversion angle and target valgus angle, as the striking direction of the external acetabular cup impactor is adjusted, the corrected real-time anteversion angle and real-time valgus angle approach the target anteversion angle and target valgus angle through continuous iteration, so that the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are consistent with the target anteversion angle and target valgus angle, thereby realizing the positioning and installation of the acetabular cup prosthesis.

2. A total hip replacement navigation system according to claim 1, characterized in that: According to the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis, the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are compensated and corrected by a weighted fusion method.

3. The total hip replacement navigation system according to claim 1, wherein: The target anteversion angle and target valgus angle are determined based on the initial anteversion angle and initial valgus angle of the hip joint as well as the patient's height, weight and lesion location. The positioning device also includes: a display unit connected to the data processing module to send the target anteversion angle and target valgus angle to the data processing module.

4. The total hip replacement navigation system according to claim 1, wherein: The data acquisition module includes: A triaxial accelerometer is used to measure the initial acceleration of the hip joint and the dynamic acceleration of the acetabular cup prosthesis during the installation process of the acetabular cup prosthesis; A three-axis gyroscope is used to measure the dynamic angular velocity during the installation of the acetabular cup prosthesis.

5. The total hip replacement navigation system according to claim 1, wherein: The positioning device is preoperatively installed on the left or right side of the reference device according to the patient's lesion location to perform initial alignment and obtain the initial anteversion angle and initial valgus angle of the hip joint; After the initial alignment is completed, the positioning device is removed from the reference datum device and installed on the acetabular cup impactor.

6. The total hip replacement navigation system according to claim 1, wherein: The method of use includes the following steps: A reference device is mounted on the pelvis of a supine patient, and a positioning device is mounted on the reference device for initial alignment to detect the initial acceleration of the hip joint; based on the initial acceleration of the hip joint, the initial anteversion angle and initial valgus angle of the hip joint are obtained using a dual-vector positioning method; and based on the initial anteversion angle and initial valgus angle of the hip joint, the target anteversion angle and target valgus angle are determined; After the initial alignment is completed, the positioning device is removed from the reference device and installed on the acetabular cup impactor to detect the real-time acceleration information and dynamic angular velocity of the acetabular cup prosthesis; According to the real-time acceleration of the acetabular cup prosthesis, the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are obtained by the double-vector positioning method; According to the dynamic angular velocity of the acetabular cup prosthesis when the acetabular cup striker is struck to adjust the installation position of the acetabular cup prosthesis, the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis are obtained by the quaternion posture determination method; According to the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis, the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are compensated and corrected; the corrected real-time anteversion angle and real-time valgus angle are compared with the target anteversion angle and target valgus angle. When the corrected real-time anteversion angle and real-time valgus angle are inconsistent with the target anteversion angle and target valgus angle, as the striking direction of the external acetabular cup impactor is adjusted, the corrected real-time anteversion angle and real-time valgus angle approach the target anteversion angle and target valgus angle through continuous iteration, so that the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis are consistent with the target anteversion angle and target valgus angle, thereby achieving the positioning and installation of the acetabular cup prosthesis.

7. The total hip replacement navigation system according to claim 6, wherein: The specific method of obtaining the real-time anteversion angle and real-time valgus angle of the acetabular cup prosthesis by the dual-vector positioning method includes: There are two rectangular coordinate systems in three-dimensional space Department and System, n is the pelvic coordinate system, b is the acetabular cup prosthesis coordinate system, and two non-collinear reference vectors are known. and , the projection coordinates in the two coordinate systems are recorded as , and , , solved by known projection coordinates Department and The azimuth relationship between the two coordinate systems is described by the direction cosine matrix, which is recorded as , reference vector and exist Department and The following conversion relationship exists under the system: (1) (2) In order to solve , and then construct a vector equation by cross-multiplying equation (1) by equation (2) to obtain the vector equation: (3) According to formula (1), formula (2) and formula (3), the matrix form is as follows: in, and for and The coordinate representation in the n system is: and for and The coordinate representation in the b system is: They are and Coordinate representation of the cross product vector in n-system and b-system; The attitude angle from system b to system n is obtained by equation (4), which is called dual-vector attitude determination. The real-time anteversion and valgus angles of the acetabular cup prosthesis are obtained by using the dual-vector positioning method: ； (5) In formula (5) It is the real-time anteversion angle and real-time valgus angle, are the accelerations of the x-axis, y-axis, and z-axis respectively.

8. The total hip replacement navigation system according to claim 6, wherein: According to the dynamic angular velocity of the acetabular cup prosthesis when the acetabular cup striker is struck, the specific method for obtaining the dynamic anteversion angle and dynamic valgus angle of the acetabular cup prosthesis by the quaternion posture determination method includes: Assume that the space is a vector Expressed in quaternion form: in, is the real part, 、 and are the coefficients of the imaginary parts i, j and k respectively, Vector Rotate an angle to another coordinate system The vector representation is: , so the transformation relationship between the two coordinate systems is: in: ; ； ； In this system, when the pelvic coordinate system is converted to the acetabular cup prosthesis coordinate system using quaternion, the transformation matrix is: The quaternion differential equation is expressed as: In formula (9) , is the angular velocity of the acetabular cup prosthesis coordinate system relative to the pelvic coordinate system, is the angular velocity in the x direction in the acetabular cup prosthesis coordinate system, is the angular velocity in the y direction of the acetabular cup prosthesis coordinate system, is the angular velocity in the z direction of the acetabular cup prosthesis coordinate system, from which the dynamic anteversion angle of the acetabular cup prosthesis is calculated and dynamic valgus angle They are: 。

Images