A Real-Time Three-Dimensional Angle Measurement Device and Calibration Method for Acetabular Grinding Drilling Based on Inertial Navigation

Abstract

This invention discloses a real-time three-dimensional angle measurement device and calibration method for acetabular grinding drilling based on inertial navigation, belonging to the technical field of medical electronic equipment. It includes a rigid housing, a clamping interface for rigid connection with a surgical drill or acetabular grinder, a circuit board, an inertial measurement unit, a data processing unit, a display and prompting unit, a zero-trigger unit, and a power management unit. Under intraoperative reference posture, the zero-trigger unit records the baseline posture, and then real-time acquisition of three-axis angular velocity and three-axis acceleration is performed to calculate the change in the current posture relative to the baseline posture. The forward tilt angle and abduction angle are extracted based on the instrument's working axis vector. The measurement device suppresses the influence of roll angle generated by rotation around the instrument's working axis on the clinical angle output, allowing the surgeon to focus primarily on angle deviations related to the drilling or grinding axis direction. This invention eliminates the need for external optical cameras and complex registration, enabling continuous, relative, and intuitive intraoperative angle feedback with miniaturized hardware.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical electronic equipment, and in particular to a real-time measurement device and calibration method for three-dimensional angles of acetabular drilling and polishing based on inertial navigation. BACKGROUND

[0002] At present, in the process of total hip arthroplasty, revision and related acetabular side bone surface treatment, the direction of acetabular polishing, drilling or guide needle placement will affect the acetabular cup placement angle, bone bed stress distribution and postoperative joint stability. In actual surgery, the doctor usually needs to observe the surgical field, the posture of the handheld instrument and the patient's bone markers at the same time, so that the real-time feedback of the instrument axis angle is required.

[0003] The existing auxiliary methods mainly include mechanical guides, optical navigation systems, preoperative custom-made guides and simple level type angle meters. The mechanical guide is intuitive in structure, but the reading depends on the visual angle and experience of the surgeon, and it is difficult to continuously feedback the dynamic angle; the optical navigation system can provide spatial pose, but the device cost is high, the arrangement is complex, and the reflective markers are easily blocked by the surgeon, the instrument or the sterile drape; the preoperative custom-made guide depends on image planning and bone surface fitting, and if bone spurs, soft tissue obstruction or bone surface treatment changes occur during the operation, the position deviation of the guide will directly transfer to the angle error.

[0004] For ordinary electronic inclinometers installed on surgical electric drills or polishing handles, the output is usually the absolute angle relative to the direction of gravity or geographic coordinates, which cannot effectively eliminate the interference caused by the instrument clamping direction, screen installation direction and electric drill rotation around its own axis. In the acetabular drilling or polishing scene, the clinician is really concerned about the changes in the forward tilt and abduction of the drill rod or polishing rod axis relative to the intraoperative reference posture, while the self-rotation angle around the axis usually does not change the direction of the hole or grinding axis. If the horizontal roll self-rotation is displayed together, it will increase the understanding burden of the surgeon.

[0005] In view of the above related technologies, it is necessary to provide a handheld measurement device which is low in cost, free of obstruction, can be quickly clamped, can be relatively zeroed and can directly output the clinically concerned angle. SUMMARY

[0006] The present application provides a real-time measurement device and calibration method for three-dimensional angles of acetabular drilling and polishing based on inertial navigation, which can use an inertial measurement unit to obtain real-time attitude changes, use a microcontroller to complete axis angle calculation and horizontal roll redundancy filtering, and provide continuous feedback to the surgeon through a screen or a prompt signal, while having a power supply, charging, button and circuit integration structure suitable for surgical instruments.

[0007] The technical solution of the present application to solve the above technical problems is as follows:

[0008] The application discloses a device for real-time measurement of three-dimensional angles of a hip reamer based on inertial navigation, which comprises a rigid shell, a clamping interface and a circuit carrier plate.

[0009] The circuit carrier plate is arranged in the rigid shell, and the circuit carrier plate is provided with an inertial measurement unit, a data processing unit, a display and prompting unit, a zero-reset triggering unit and a power management unit.

[0010] The inertial measurement unit is used for collecting three-axis angular velocity data and three-axis acceleration data.

[0011] The data processing unit is electrically connected with the inertial measurement unit, and the data processing unit is configured to perform the following operations: in response to a zero-reset instruction, recording current attitude information as a reference attitude; updating the current attitude according to the data collected by the inertial measurement unit in real time; calculating the relative rotation of the current attitude relative to the reference attitude; based on the fixed transformation relationship between the measurement coordinate system and the working shaft of the instrument, extracting the direction vector of the working shaft of the instrument in the current space; projecting the direction vector to a preset clinical reference plane to calculate the anteversion angle and the abduction angle, and suppressing the roll angle component generated by the self-rotation of the working shaft of the instrument;

[0012] The display and prompting unit is arranged on the surface of the rigid shell and located on the visual side of the operator, and the display and prompting unit is used for displaying the anteversion angle and the abduction angle calculated by the data processing unit.

[0013] The zero-reset triggering unit is used for receiving the operation of a user to generate the zero-reset instruction.

[0014] The power management unit is used for supplying power to the device and managing the electric energy.

[0015] Further, the data processing unit is configured to:

[0016] define a reference coordinate system, wherein the front-rear direction is an anteversion reference axis, the inside-outside direction is an abduction reference axis, and the vertical direction is a gravity axis; project the direction vector of the working shaft of the instrument to a sagittal plane formed by the anteversion reference axis and the vertical axis, and to a coronal plane formed by the abduction reference axis and the vertical axis; determine the anteversion angle according to the projection included angle in the sagittal plane, and determine the abduction angle according to the projection included angle in the coronal plane.

[0017] Further, the data processing unit is further configured to:

[0018] The static state detection is performed after the system is started, the gyro zero bias is estimated based on the angular velocity data in the static state, and the zero bias compensation is performed on the real-time collected angular velocity data; the complementary filtering, extended Kalman filtering or gradient descent algorithm is used to perform attitude fusion on the angular velocity data and the acceleration data after the zero bias compensation, so as to obtain the current attitude.

[0019] Further, the clamping interface is one or more of a ring sleeve, a half-ring clamping jaw, a threaded locking sleeve ring, a quick-release buckle or a special adapter seat, and a fixed relative relationship is maintained between the measurement coordinate system of the inertial measurement unit and the instrument working shaft.

[0020] Further, the power management unit includes one or more of a USB interface, a charging management circuit, a battery interface, a voltage stabilizing circuit, a key-on circuit, an under-voltage protection circuit and a power detection circuit.

[0021] A calibration method of a hip acetabulum polishing and drilling three-dimensional angle real-time measurement device based on inertial navigation, adopts a hip acetabulum polishing and drilling three-dimensional angle real-time measurement device based on inertial navigation, and the method comprises the following steps:

[0022] S1 clamping and fixing: the measurement device is rigidly connected to a surgical electric drill, an acetabulum polisher or a guide rod through a clamping interface, and a fixed transformation relationship between the measurement coordinate system and the instrument working shaft is established;

[0023] S2 initialization: starting the measurement device, estimating the static zero bias of the inertial measurement unit, and obtaining the gyro zero bias compensation parameter;

[0024] S3 relative zeroing: adjusting the instrument to an intraoperative reference direction, triggering a zeroing instruction, and recording the attitude information at this time as a reference attitude;

[0025] S4 real-time attitude solving: real-time collection of three-axis angular velocity and three-axis acceleration data, attitude fusion combined with the zero bias compensation parameter, and obtaining the current attitude quaternion or rotation matrix;

[0026] S5 relative rotation calculation: calculating the relative rotation amount of the current attitude relative to the reference attitude;

[0027] S6 axis projection and angle extraction: determining the real-time direction vector of the instrument working shaft based on the relative rotation amount and the fixed transformation relationship; projecting the real-time direction vector to a preset clinical reference plane to calculate the anteversion angle and the abduction angle, and filtering out the roll angle component generated by the self-rotation around the instrument working shaft in the calculation process;

[0028] S7 feedback output: real-time output of the anteversion angle and the abduction angle to a display and prompt unit for visual display.

[0029] Further, the specific process of the roll angle component in step S6 comprises:

[0030] Constructing an instrument coordinate system, wherein the Z-axis is along the instrument working axis direction;

[0031] Obtaining the direction vector of the Z-axis in the world coordinate system or the reference coordinate system under the current posture;

[0032] Ignoring the Euler angle component (roll angle) of rotation around the Z-axis;

[0033] Only according to the projection components of the Z-axis vector on the sagittal plane and the coronal plane, respectively, the anteversion angle and the abduction angle are calculated.

[0034] Further, the relative zeroing in step S3 includes a single-point zeroing mode or a double-plane calibration mode:

[0035] In the single-point zeroing mode, the current posture is directly collected as the reference;

[0036] In the double-plane calibration mode, two sets of inertial data are collected in turn when the instrument is in the first reference posture and the second reference posture, the installation deviation matrix between the measurement coordinate system and the instrument coordinate system is solved by using two non-parallel posture vectors, and the deviation matrix is introduced for correction in subsequent step S6.

[0037] Further, after step S7, there is also step S8 deviation monitoring:

[0038] Setting the target anteversion angle, the target abduction angle and the tolerance threshold; real-time calculating the first deviation of the current anteversion angle and the target anteversion angle, and the second deviation of the current abduction angle and the target abduction angle;

[0039] If the first deviation and the second deviation are both within the tolerance threshold, the control display and prompt unit is prompted to reach the position; otherwise, the deviation direction and size are output.

[0040] Further, after step S8, there is also step S9 abnormality processing:

[0041] During the measurement process, whether the angular velocity is out of limit, whether the acceleration data is saturated, whether the zeroing state is valid and whether the battery power is lower than the threshold value are monitored in real time;

[0042] When any abnormality is detected, the control display and prompt unit outputs the re-zeroing prompt, the slow operation prompt or the charging maintenance prompt, and can freeze the current angle according to the preset strategy.

[0043] In summary, compared with the prior art, the beneficial effects of the above technical solutions are:

[0044] 1、The application has the effects of no occlusion and high degree of freedom, adopts the principle of inertial navigation, breaks away from the dependence on external optical tracking equipment, avoids the intraoperative occlusion problem, and allows the doctor to freely operate in the narrow space in the deep part of the acetabulum.

[0045] 2、The application has the effects of de-redundancy and strong correlation, and through axis projection solution and roll redundancy suppression algorithm, only the anteversion angle and abduction angle of clinical concern are output, the interference data generated by the instrument spin is shielded, and the visual recognition difficulty and misoperation risk of the operator are significantly reduced.

[0046] 3、The application has the effects of fast calibration and high efficiency, based on the relative measurement mode of one-key zeroing, the complex registration process of traditional navigation is simplified, the reference coordinate system can be reset at any time during the operation, and the operation preparation time is greatly shortened.

[0047] 4、The application has the effects of miniaturization and anti-interference, high integration circuit design is adopted on the hardware, and the anti-vibration performance of the IMU is optimized through specific PCB layout, forming a small-sized auxiliary tool suitable for the operation environment. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 The structure diagram of the measuring device of the application Figure 1 ;

[0049] Figure 2 The structure diagram of the measuring device of the application Figure 2 ;

[0050] Figure 3 The structure diagram of the measuring device of the application Figure 3 ;

[0051] Figure 4 The structure diagram of the measuring device of the application Figure 4 ;

[0052] Figure 5 The physical object of the measuring device of the application Figure 1 ;

[0053] Figure 6 The physical object of the measuring device of the application Figure 2 ;

[0054] Figure 7 The circuit principle diagram of the measuring device of the application

[0055] Figure 8 The control board PCB layout diagram of the measuring device of the application

[0056] Figure 9 The flow chart of the posture acquisition, zeroing calibration and angle display in the measuring device of the application

[0057] Figure 10 The flow chart of the axis angle solution and redundant roll filtering in the measuring device of the application

[0058] Figure 11Flow chart for power start, charge management and low power consumption control in the measuring device of the present application.

[0059] Figure 12 Flow chart for clinical use of the measuring device of the present application in acetabular side polishing and drilling operation. DETAILED DESCRIPTION

[0060] The principles and features of the present application are described below in conjunction with all the drawings, and the examples are only used to explain the present application and not to limit the scope of the present application.

[0061] The embodiment of the present application discloses a three-dimensional angle real-time measuring device and calibration method for acetabular polishing and drilling based on inertial navigation. The present application belongs to the technical field of orthopedic surgery auxiliary navigation, inertial attitude measurement, handheld surgical instrument angle feedback and medical electronic equipment, and specifically relates to a three-dimensional angle real-time measuring device that can be installed on an acetabular polisher or a surgical electric drill, and a calibration and measurement method based on relative zeroing, axis attitude solving and redundant spin suppression.

[0062] Referring to Figures 1 to 8 As shown in the figure, a three-dimensional angle real-time measuring device for acetabular polishing and drilling based on inertial navigation includes a rigid shell, a clamping interface, an inertial measurement unit, a data processing unit, a display and prompting unit, a zeroing trigger unit and a power management unit.

[0063] The clamping interface is used to form a detachable rigid connection between the rigid shell and the surgical electric drill, the acetabular polisher, the drill rod sheath or the guide rod. The inertial measurement unit is used to collect three-axis angular velocity and three-axis acceleration. The data processing unit is used to record the reference attitude based on the zeroing instruction generated by the zeroing trigger unit, and to calculate the anteversion angle and abduction angle of the instrument working shaft according to the change of the current attitude relative to the reference attitude. The display and prompting unit is used to output the anteversion angle and abduction angle.

[0064] The clamping interface is one or more of a ring sleeve, a half-ring clamping jaw, a threaded locking sleeve, a quick-release buckle or a special adapter seat, and keeps the measurement coordinate system of the inertial measurement unit in a fixed relative relationship with the instrument working shaft. The inertial measurement unit is a six-axis MEMS inertial chip, which is connected with the data processing unit through an SPI or I2C bus. The data processing unit is configured to perform stillness detection and gyro zero offset estimation after system startup, and update the zero offset compensation parameters within a time window that meets the stillness condition. The data processing unit is configured to record the attitude at the zeroing moment as a reference quaternion, a reference rotation matrix or a reference axis vector, and obtain the direction change of the instrument working shaft according to the relative rotation of the current attitude and the reference attitude. The data processing unit is configured to calculate the anteversion angle and the abduction angle based on the plane projection of the instrument working shaft vector, and suppress the influence of the roll angle component generated by the self-rotation of the instrument working shaft on the display output. The zeroing trigger unit includes a button, a touch area or an external trigger interface arranged on the surface of the rigid shell, and the data processing unit averages, moving averages or robustly averages the attitude data within a preset time window after the zeroing trigger.

[0065] It also includes a target angle setting module for setting a target anteversion angle, a target abduction angle and a tolerance range, and a display and prompting unit outputs a positioning prompt or a deviation prompt according to the deviation between the current angle and the target angle.

[0066] The power management unit includes one or more of a USB interface, a charging management circuit, a battery interface, a voltage stabilizing circuit, a key-on circuit, an under-voltage protection circuit and a power detection circuit.

[0067] It also includes a circuit carrier board on which the data processing unit, the inertial measurement unit, the display and prompting unit, the zeroing trigger unit, the key interface, the clamping interface and the power management unit are integrated, and the inertial measurement unit is arranged away from the large-current charging path and the switching power supply inductor.

[0068] The clamping interface is arranged at one end or side of the rigid shell, and is used to form a detachable rigid connection with a surgical drill, a polishing handle, a drill rod sheath or a guide rod, so that the preset measurement axis of the measurement device keeps a fixed relative relationship with the instrument working shaft.

[0069] The inertial measurement unit is arranged inside the rigid shell and keeps a known mounting relationship with the instrument working shaft, and is used to collect three-axis angular velocity and three-axis acceleration data. The data processing unit is electrically connected with the inertial measurement unit, and is used to perform sensor initialization, zero offset estimation, attitude fusion, relative attitude calculation, axis projection, angle mapping and display refreshing. The display and prompting unit is arranged on the side easily observed by the operator, and is used to display the current anteversion angle, the abduction angle, the target angle deviation, the zeroing state and the power state. The zeroing trigger unit is used to record the reference attitude when the instrument is in the intraoperative reference attitude.

[0070] The present application aims at the problems of discontinuous mechanical reading, easy shielding of optical navigation, difficulty in adapting intraoperative relative coordinates for absolute inclinometer and interference caused by roll angle display in the prior art, and provides a three-dimensional angle real-time measurement device for acetabular polishing drilling based on inertial navigation.

[0071] The present application provides a hardware implementation. The data processing unit can adopt a microcontroller with wireless communication capability, the inertial measurement unit can adopt a six-axis MEMS inertial chip, the display unit can adopt an OLED / LCD display screen with I2C or SPI interface, and the power management unit can include a USB interface, a charging management chip, a battery interface, a voltage reduction or voltage increase stabilizing circuit, a switch button and an electric quantity detection circuit. The circuit carrier board can integrate the microcontroller, the inertial measurement unit, the display interface, the button interface, the power management chip and the external connector on the same rigid or rigid-flexible combined circuit carrier board.

[0072] The present application can also include a target angle setting and tolerance prompting function. The doctor can set the desired anteversion and abduction angles according to the preoperative plan or experience, and the system can calculate the deviation between the current angle and the target angle in real time. When the deviation is within the preset tolerance range, the display and prompting unit outputs an in-place prompt; when the deviation exceeds the tolerance range, the display unit gives a directional deviation or a numerical deviation.

[0073] Compared with the prior art, the present application has at least the following beneficial effects:

[0074] I. The device is based on inertial measurement and does not rely on external cameras and visual markers, which can avoid intraoperative shielding;

[0075] II. The relative coordinate system is established by one-key zeroing during surgery, which reduces the complexity of preoperative registration;

[0076] III. The instrument axis is calculated and the roll redundancy is suppressed, which focuses the attention of the doctor on the key angles such as anteversion and abduction;

[0077] IV. The display module is integrated with the clamping structure, which is convenient for the operator to continuously observe during the operation;

[0078] V. The hardware circuit integrates the microcontroller, the IMU, the display interface and the power management, which can form a rechargeable and reusable small-sized surgical auxiliary tool.

[0079] Embodiment I: device structure

[0080] In one embodiment, the measurement device comprises a rigid housing, a clamping interface, a display window, a key area, a circuit board and a battery compartment. The rigid housing can be made of sterilizable material or covered with a disposable sterile protective cover. The housing can be cylindrical, box-shaped or attached to the drill. The clamping interface can be a ring sleeve, a half-ring clamp, a quick-release buckle, a screw locking ring or a special adapter seat matched with the drill shell.

[0081] The clamping interface is used to form a stable rigid connection between the measurement device and the instrument body. The connection does not require the measurement device and the drill rod to be completely coaxial in geometry, but a fixed transformation relationship between the measurement coordinate system and the instrument working axis should be obtained during factory calibration or preoperative calibration. Through this transformation relationship, the data processing unit can convert the attitude change of the inertial measurement unit into the attitude change of the drill bit, polishing head or guide rod axis.

[0082] The display window is located on the surface of the housing that is easy to observe when the operator holds it. The display content can include the anteversion angle, the abduction angle, the zeroing prompt, the target deviation, the system stable state, the battery power and the abnormal alarm. The key area includes at least a zeroing key, and can further include a target angle plus / minus key, a mode switching key, a power on / off key and a confirmation key.

[0083] The circuit board is arranged inside the rigid housing. The circuit board can be mounted with a microcontroller, an inertial measurement unit, a display and prompt unit, a power management chip, a charging interface, a battery connection terminal, a status indicator light and necessary filter capacitors. Figure 3 A hardware schematic diagram is shown, which includes a microcontroller, an IMU, a display interface and a power management circuit, Figure 4 A PCB layout of the above-mentioned devices on the control board is shown.

[0084] Embodiment two: hardware circuit connection

[0085] In one embodiment, the data processing unit uses an ESP32-S3 series microcontroller, and the inertial measurement unit uses an ICM42688-P or other six-axis inertial chip. The inertial measurement unit is connected to the microcontroller through an SPI bus to obtain a higher sampling rate and lower communication delay; the display unit can be connected to the microcontroller through an I2C bus; the zeroing key, the power on / off key and the interrupt signal are connected to the general input / output pins of the microcontroller, respectively.

[0086] The hardware circuit further includes a USB interface and a power management circuit. The USB interface can be used for charging, firmware download or debugging; the power management chip can realize battery charging, system power path selection, voltage stabilization output, key power on, undervoltage protection and power detection. The decoupling capacitor on the circuit board is arranged close to the microcontroller, the IMU and the voltage stabilizing chip to reduce the influence of power supply ripple on the stability of the inertial measurement.

[0087] In terms of PCB layout, the IMU region is preferably far away from large current charging path, switching power supply inductance and high-speed USB differential line, and is located at a position rigidly connected with the shell as much as possible. The microcontroller, display and prompt unit and the key connector are arranged according to the assembly direction, so as to shorten the cable and improve the assembly reliability. The above layout enables the measurement device to integrate the functions of attitude acquisition, data processing, display and power supply on a small size control board.

[0088] Example three: zeroing calibration

[0089] Before the surgical use, the surgeon or the assistant fixes the measurement device on the electric drill, the acetabular reamer handle or the guide rod, and confirms the locking of the clamping mechanism. After the system is started, the data processing unit reads the acceleration and angular velocity data output by the inertial measurement unit, and estimates the gyro zero offset in the static window. The static window can be judged by the angular velocity threshold, the acceleration change threshold and the duration.

[0090] When the drill bit or the polishing head reaches the reference direction selected by the surgeon, the surgeon presses the zeroing key. The data processing unit performs sliding average or robust average on the attitude data within a preset time window, and records the reference attitude. The reference attitude can be represented as a quaternion q0, a rotation matrix R0 or a reference axis vector a0. After zeroing is completed, the display unit displays the anteversion angle and the abduction angle as zero values or displays the target relative deviation.

[0091] In order to reduce the single artificial zeroing error, the system can provide secondary confirmation or double plane calibration mode. The double plane calibration mode includes first reference direction acquisition and second reference direction acquisition, and the data processing unit estimates the installation deviation between the measurement coordinate system and the instrument axis coordinate system according to two known attitudes or two anatomical reference planes. For the instrument adapter that needs to be repeatedly used, the installation deviation calibration can be completed at the factory or maintenance stage and stored in the microcontroller nonvolatile memory.

[0092] Example four: angle calculation and roll redundancy filtering

[0093] During the measurement process, the inertial measurement unit outputs three-axis angular velocity and three-axis acceleration at a set sampling frequency. The data processing unit compensates the angular velocity for zero offset, and combines the acceleration direction to perform complementary filtering, extended Kalman filtering, gradient descent attitude fusion or other attitude estimation algorithms, so as to obtain the current attitude qt or Rt.

[0094] The data processing unit calculates the relative rotation of the current attitude relative to the reference attitude. Taking the quaternion as an example, the relative rotation can be represented as qrel equal to the inverse of q0 multiplied by qt. Subsequently, the system does not directly convert the relative rotation into complete Euler angles and display all of them, but first calculates the direction change of the current instrument axis in the reference coordinate system according to the known instrument working axis vector.

[0095] When the instrument rotates around its own working axis, the rotation will change the roll angle of the housing or display screen, but will not change the spatial orientation of the drill bit, the polishing head or the guide rod. The present application uses axis vector projection to extract the anteversion and abduction direction components and suppress the influence of the spin around the axis on the clinical angle output. Thus, the doctor does not need to deliberately maintain the screen orientation or the electric drill roll posture, but only needs to adjust the instrument axis according to the displayed anteversion and abduction deviation.

[0096] In an implementation manner, the system defines the front-back direction, the in-out direction and the vertical direction in the reference coordinate system as the clinical coordinate base. When the instrument axis is projected onto the sagittal plane and the coronal plane respectively, the included angles after the projection are mapped as the anteversion angle and the abduction angle respectively. If the angle change exceeds the preset limit value or the sensor is saturated, the system can freeze the display, prompt to re-zero or require re-acquisition.

[0097] Embodiment five: display, prompt and data recording

[0098] The display unit can adopt a digital display mode, a two-axis scale mode or a target deviation mode. The digital display mode directly displays the current anteversion angle and the abduction angle; the two-axis scale mode indicates the size of the deviation of the instrument axis from the target direction with a horizontal and vertical deviation bar; the target deviation mode displays the difference between the current angle and the preoperative planned angle or the doctor set angle.

[0099] The prompt unit can include a buzzer, a vibration motor, an indicator light or a screen color change. When the current angle enters the target tolerance range, the system outputs a prompt that is in place; when the angle deviation is too large, the zeroing state is invalid, the power is insufficient or the sensor is abnormal, the system outputs an alarm prompt. For a sterile use scene, the prompt signal should be simple to avoid the operator making complex menu selections during critical operations.

[0100] The data processing unit can also record the zeroing time, the measurement time, the maximum angle deviation, the target angle, the actual stable angle and the abnormal events. The recorded data can be sent to an external terminal through USB or wireless communication for postoperative quality traceability, training evaluation or equipment maintenance. The wireless communication function is not a necessary condition to achieve the core purpose of the present application, but can be used as an extended function.

[0101] Embodiment six: surgical cooperation process

[0102] Before the acetabular side polishing or drilling, the assistant completes the device clamping and self-checking. The doctor adjusts the instrument to the intraoperative reference direction and triggers the zeroing. Then, during the polishing, drilling or guide needle placement process, the doctor observes the anteversion angle and the abduction angle shown by the display unit, and adjusts the wrist and the instrument axis according to the target value. When the angle is stable within the target range, the doctor continues to perform the polishing or drilling operation.

[0103] If the drill, drill bit or clamping position needs to be changed during the operation, the system prompts to re-zero. If the patient's position, pelvic reference direction or surgical target changes, the doctor can reselect the reference attitude and trigger zero again. Through the above process, the present application provides relative, continuous and readable digital angle feedback for the acetabular side instrument axis without relying on large navigation equipment.

[0104] Referring to Figures 9 to 12 The calibration method of the real-time measurement device for three-dimensional angles of acetabular reaming and drilling based on inertial navigation includes:

[0105] Fix the measurement device to the surgical drill, acetabular reamer or guide rod; start the measurement device and estimate the zero bias of the inertial measurement unit; trigger zero and record the reference attitude when the instrument is in the intraoperative reference direction; real-time acquisition of inertial data and update of the current attitude; calculation of the relative rotation of the current attitude relative to the reference attitude; calculation of the anteversion angle and abduction angle according to the change of the instrument working shaft direction; and output of the anteversion angle and abduction angle through the display and prompt unit.

[0106] The calculation of the anteversion angle and abduction angle includes projecting the instrument working shaft vector to the preset clinical coordinate plane, and obtaining the anteversion angle and abduction angle according to the projection angle, while not outputting the roll spin angle around the instrument working shaft as a clinical angle.

[0107] Zeroing includes single-point zeroing or double-plane calibration; double-plane calibration estimates the installation deviation between the measurement coordinate system and the instrument working shaft coordinate system by acquiring two reference attitudes.

[0108] During the measurement process, when the sensor data is saturated, the angular velocity exceeds the threshold, the zeroing state is invalid or the battery power is lower than the threshold, the display and prompt unit outputs the re-zeroing, slow operation or charging maintenance prompt.

[0109] A calibration method of a real-time measurement device for three-dimensional angles of acetabular reaming and drilling based on inertial navigation includes the following steps:

[0110] S1 clamping and fixing: rigidly connect the measurement device to the surgical drill, acetabular reamer or guide rod through the clamping interface, and establish a fixed transformation relationship between the measurement coordinate system and the instrument working shaft;

[0111] S2 initialization: start the measurement device, estimate the static zero bias of the inertial measurement unit, and obtain the gyro zero bias compensation parameters;

[0112] S3 relative zeroing: adjust the instrument to the intraoperative reference direction, trigger the zeroing instruction, and record the attitude information at this time as the reference attitude;

[0113] Relative zeroing includes single-point zeroing mode or double-plane calibration mode:

[0114] In the single-point zeroing mode, the current posture is directly collected as the reference;

[0115] In the dual-plane calibration mode, two sets of inertial data are collected in sequence when the instrument is in the first reference posture and the second reference posture, the installation deviation matrix between the measurement coordinate system and the instrument coordinate system is solved by using two non-parallel posture vectors, and the deviation matrix is introduced for correction in the subsequent step S6.

[0116] S4 Real-time posture solving: real-time collection of three-axis angular velocity and three-axis acceleration data, combination of zero offset compensation parameters for posture fusion, and obtaining of current posture quaternion or rotation matrix;

[0117] S5 Relative rotation calculation: calculation of the relative rotation amount of the current posture relative to the reference posture;

[0118] S6 Axis projection and angle extraction: based on the relative rotation amount and the fixed transformation relationship, the real-time direction vector of the instrument working axis is determined; the real-time direction vector is projected to the preset clinical reference plane, and the anteversion angle and the abduction angle are calculated, and the roll angle component generated by the self-rotation around the instrument working axis is filtered out in the calculation process;

[0119] The specific process of the roll angle component includes:

[0120] An instrument coordinate system is constructed, wherein the Z-axis is along the direction of the instrument working axis;

[0121] The direction vector of the Z-axis in the world coordinate system or the reference coordinate system under the current posture is obtained;

[0122] The Euler angle component (roll angle) of the rotation around the Z-axis is ignored;

[0123] Only according to the projection components of the Z-axis vector on the sagittal plane and the coronal plane, the anteversion angle and the abduction angle are calculated respectively.

[0124] S7 Feedback output: the anteversion angle and the abduction angle are output in real time to the display and prompting unit for visual display.

[0125] S8 Deviation monitoring: setting the target anteversion angle, the target abduction angle and the tolerance threshold; real-time calculation of the first deviation of the current anteversion angle from the target anteversion angle and the second deviation of the current abduction angle from the target abduction angle;

[0126] If the first deviation and the second deviation are both within the tolerance threshold, the display and prompting unit is controlled to issue a positioning prompt; otherwise, the deviation direction and size are output.

[0127] S9 Abnormal handling: in the measurement process, whether the angular velocity is out of limit, whether the acceleration data is saturated, whether the zeroing state is valid and whether the battery power is lower than the threshold are monitored in real time;

[0128] When any abnormality is detected, the control displays and outputs a re-zeroing prompt, a slow operation prompt or a charging maintenance prompt to the prompting unit, and can freeze the current angle according to a preset strategy.

[0129] The implementation principle of the real-time measurement device and calibration method for three-dimensional angles of a hip reamer based on inertial navigation is as follows:

[0130] The measurement device is fixed to a surgical electric drill or a hip reamer; after being started, the inertial measurement unit is estimated for static zero offset; the zeroing is triggered when the drill bit, the reamer head or the guide rod is in the intraoperative reference direction; the data processing unit records the reference attitude quaternion, the reference axis vector or the equivalent attitude matrix; the inertial data are collected in real time and the current attitude is updated; the relative rotation is calculated according to the current attitude and the reference attitude; the changes in the anteversion and abduction directions are extracted based on the instrument working axis vector; the roll spin around the instrument working axis is not output as a clinical angle; and the processed angle is output in the form of a number, a symbol, a scale or a prompt signal.

[0131] The above only describes the preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A real-time three-dimensional angle measurement device for acetabular grinding drilling based on inertial navigation, characterized in that: It includes a rigid housing, a clamping interface, and a circuit board. The clamping interface is installed on one side of the rigid housing and is used to form a detachable rigid connection between the rigid housing and a surgical drill, an acetabular grinder, or a guide rod, so that the measurement coordinate system inside the rigid housing maintains a fixed relative transformation relationship with the working axis of the instrument. The circuit board is placed inside a rigid housing, and the circuit board is equipped with an inertial measurement unit, a data processing unit, a display and prompt unit, a zero-trigger unit, and a power management unit. The inertial measurement unit is used to acquire triaxial angular velocity data and triaxial acceleration data; The data processing unit is electrically connected to the inertial measurement unit and is configured to perform the following operations: in response to a zeroing command, record the current attitude information as a reference attitude; The current attitude is updated based on data collected in real time by the inertial measurement unit; Calculate the relative rotation of the current posture relative to the reference posture; based on the relative rotation and the fixed transformation relationship between the measurement coordinate system and the instrument working axis, extract the direction vector of the instrument working axis in the current space; project the direction vector onto the preset clinical reference plane, calculate the forward tilt angle and abduction angle, and suppress the roll angle component generated by the spin around the instrument working axis; The display and prompting unit is mounted on the surface of the rigid housing and located on the surgeon's visible side. The display and prompting unit is used to display the anteversion angle and abduction angle calculated by the data processing unit. The zero-reset trigger unit is used to receive user operations to generate a zero-reset instruction; The power management unit is used to supply power to the device and manage electrical energy.

2. The real-time three-dimensional angle measurement device for acetabular grinding and drilling based on inertial navigation according to claim 1, characterized in that: The data processing unit is configured as follows: Define a reference coordinate system, where the anterior-posterior direction is the anteversion reference axis, the lateral-interior direction is the abduction reference axis, and the vertical direction is the gravity axis; project the direction vector of the instrument's working axis onto the sagittal plane formed by the anteversion reference axis and the vertical axis, and the coronal plane formed by the abduction reference axis and the vertical axis, respectively; determine the anteversion angle based on the projection angle in the sagittal plane, and determine the abduction angle based on the projection angle in the coronal plane.

3. The real-time three-dimensional angle measurement device for acetabular grinding and drilling based on inertial navigation according to claim 1, characterized in that: The data processing unit is further configured to: After the system starts up, static detection is performed. The gyroscope bias is estimated based on the angular velocity data in the static state, and the bias is compensated for the real-time acquired angular velocity data. The bias-compensated angular velocity data and acceleration data are fused using complementary filtering, extended Kalman filtering, or gradient descent algorithm to obtain the current attitude.

4. The real-time three-dimensional angle measurement device for acetabular grinding and drilling based on inertial navigation according to claim 1, characterized in that: The clamping interface is one or more of the following: annular sleeve, semi-annular jaw, threaded locking collar, quick-release buckle, or special adapter seat, and maintains a fixed relative relationship between the measurement coordinate system of the inertial measurement unit and the working axis of the instrument.

5. The real-time three-dimensional angle measurement device for acetabular grinding and drilling based on inertial navigation according to claim 1, characterized in that: The power management unit includes one or more of the following: a USB interface, a charging management circuit, a battery interface, a voltage regulator circuit, a button power-on circuit, an undervoltage protection circuit, and a power detection circuit.

6. A calibration method for a real-time three-dimensional angle measurement device for acetabular grinding and drilling based on inertial navigation, characterized in that, The method of using the inertial navigation-based three-dimensional angle real-time measurement device for acetabular grinding drilling as described in any one of claims 1 to 5 includes the following steps: S1 clamping and fixing: The measuring device is rigidly connected to the surgical drill, acetabular grinder or guide rod through the clamping interface to establish a fixed transformation relationship between the measuring coordinate system and the working axis of the instrument; S2 Initialization: Start the measurement device, perform static zero bias estimation on the inertial measurement unit, and obtain the gyroscope zero bias compensation parameters; S3 Relative Zeroing: Adjust the instrument to the intraoperative reference direction, trigger the zeroing command, and record the posture information at this time as the reference posture; S4 Real-time Attitude Calculation: Real-time acquisition of three-axis angular velocity and three-axis acceleration data, combined with zero bias compensation parameters for attitude fusion, to obtain the current attitude quaternion or rotation matrix; S5 Relative Rotation Calculation: Calculates the relative rotation of the current attitude with respect to the reference attitude; S6 Axis Projection and Angle Extraction: Based on the relative rotation amount and fixed transformation relationship, the real-time direction vector of the instrument working axis is determined; the real-time direction vector is projected onto the preset clinical reference plane, and the forward tilt angle and abduction angle are calculated. During the calculation process, the roll angle component generated by the spin around the instrument working axis is filtered out. S7 Feedback Output: The forward tilt angle and abduction angle are output to the display and prompt unit in real time for visualization.

7. The real-time three-dimensional angle measurement device and calibration method for acetabular grinding drilling based on inertial navigation according to claim 6, characterized in that: The specific process of the roll angle component in step S6 includes: Construct an instrument coordinate system, where the Z-axis is along the working axis of the instrument; Obtain the direction vector of the Z-axis in the world coordinate system or the reference coordinate system under the current attitude; Ignore the Euler angle component (roll angle) of rotation about the Z-axis; The anteversion angle and abduction angle are calculated based solely on the projection components of the Z-axis vector in the sagittal and coronal planes, respectively.

8. The real-time three-dimensional angle measurement device and calibration method for acetabular grinding drilling based on inertial navigation according to claim 6, characterized in that: In step S3, relative zeroing includes single-point zeroing mode or dual-plane calibration mode: In single-point zeroing mode, the current attitude is directly collected as the reference. In the dual-plane calibration mode, two sets of inertial data of the instrument in the first reference attitude and the second reference attitude are collected in sequence. The installation deviation matrix between the measurement coordinate system and the instrument coordinate system is solved by using two non-parallel attitude vectors, and the deviation matrix is ​​introduced for correction in the subsequent step S6.

9. The real-time three-dimensional angle measurement device and calibration method for acetabular grinding drilling based on inertial navigation according to claim 6, characterized in that: Step S7 is followed by step S8, deviation monitoring: Set the target pitch angle, target flare angle, and tolerance threshold; calculate in real time the first deviation between the current pitch angle and the target pitch angle, and the second deviation between the current flare angle and the target flare angle; If both the first and second deviations fall within the tolerance threshold, the control display and prompting unit will issue a positioning prompt; otherwise, it will output the direction and magnitude of the deviation.

10. The real-time three-dimensional angle measurement device and calibration method for acetabular grinding drilling based on inertial navigation according to claim 9, characterized in that: Step S8 is followed by step S9, which involves exception handling. During the measurement process, real-time monitoring is conducted to check whether the angular velocity exceeds the limit, whether the acceleration data is saturated, whether the zeroing state is valid, and whether the battery power is below the threshold. When any abnormality is detected, the control display and prompt unit outputs a zeroing prompt, a slowdown operation prompt, or a charging maintenance prompt, and can freeze the current angle according to a preset strategy.

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