Biography
Enrollment Date: 2014
Graduation Date：2017
Degree：M.S.
Defense Date：2017.05.25
Advisors：Hong Chen
Department：Institute of Microelectronics，Tsinghua University
Title of Dissertation/Thesis：Study on the Detection System of Pelvic Pose and Prosthesis Implantation Aangles in Hip Replacement Surgery
Abstract:
With the increase population and the aging of the population, the demand for joint surgery increased year by year. Hip surgery and knee surgery are the most common surgeries among them. Hip replacement surgery is a procedure for the replacement of diseased hip joint with the prosthesis, such as the acetabulum and the femoral head, to restore the normal function of the hip joint. In hip replacement surgery, accurate implantation of prosthesis is the key to improve the success rate of operation. At the same time, the pose of the pelvis should be a reference for the implantation of prosthesis. Therefore, during hip replacement surgery, we must ensure that the pose of pelvis can be measured in real time, and then determine the implantation angle of prosthesis relative to the pelvis.
In this study, we discuss and design the pelvic pose and prosthesis implantation angle detection system, and focus on the two aspects of pelvic pose estimation and prosthesis implantation angles in hip replacement surgery. Using the data collected by the inertial sensors and the data fusion algorithm to acquire the attitude information. Based on the obtained attitude information, combined with the algorithm designed for the pose estimation of pelvis and implantation angles of the prosthesis, the pelvic pose and the prosthesis implantation angles could be determined.
First of all, we use the data collected by inertial sensors, including three axis acceleration, three axis angular velocity and three axis magnetic force, according to the complementary characteristics between them, the attitude information of the sensor module could be obtained. The data fusion algorithm for attitude determination used here is Quaternion based Extended Kalman Filter (Q-EKF). Then, according to the definition of the Anterior Pelvic Plane (APP) in the medical field, the vector value of each axis of the pelvis in the reference coordinate system could be determined by using the sensor model. Based on the relationship between the attitude of module fixed on the pelvis and the initial pose of the pelvis, the real-time attitude of the pelvis can be obtained from the inversion of the fixed module. Finally, according to the definition of the prosthesis implantation angles in medicine, namely inclination angle and anteversion angle. The implantation angles could be obtained by calculating the angle between the axis of sensor module, which is fixed on prosthesis, and the axis of pelvis.
In summary, this study focus on detection system for determination of the pose of the pelvis and implantation angles of prosthesis in hip replacement surgery, through the test of pose calculation method，the accuracy could be determined. At the same time, the research methods and results of this paper are analyzed by comparing the pelvic pose calculated based on the algorithm designed in this paper and the measured attitude of pelvis, and comparing the resolving implantation angles of prosthesis and the angle measured by protractor. The results of this study have important reference value for clinical operation.