Biography
Enrollment Date: 2007
Graduation Date：2010
Degree：M.S.
Defense Date：2010.06.04
Advisors：Chun Zhang
Department：Institute of Microelectronics，Tsinghua University
Title of Dissertation/Thesis：Design and Implementation of the Gauge System of Strain Balance in the Operation of Total Knee Replacement
Abstract:
With the development of social economic and technology, health and life quality is paid more and more attention and healthy bone is the premise for a high quality life. In China, there are ten percents of the population who have the problems of the arthritis, some of who have to undergo the operations of the total knee replacement (TKR) to live normally as the result of the ageing and physical damage of the knee joint. So artificial joint is becoming an important tool to make the patients exercise normally. Currently, the operation of the bone structure is well developed, but the strain balance between the prosthesis and the spacer is usually judged by the doctors’ skills and experience. This problem is paid more and more attention. Unsuccessful TKR operation is usually due to that improper implanted prosthesis makes the pressure not in balance so that some interfaces have to bear more pressure and accelerate the process of abrasion and damage. Implanted prosthesis will be affected by many kinds of pressure in the body so that it will have the problems of osteolysis, dislocation, loosening and etc. A system to gauge the strain between the prosthesis and the spacer in the medical operation of Total Knee Replacement is proposed, with which the doctors can know the strain distribution in the knee and the success ratio will be improved.. Two schemes are proposed by the paper. In the first scheme the load cells are used to gauge the strain, the ADC is used to convert the analogue signal to digital one, the embedded micro CPU based on FPGA is used to control the system and process the figures, Bluetooth is used as the transmission way and the results are displayed visually and in real-time by the software of Matlab. The structure and the working ways of the system are introduced, and the test scheme and test results are given too. The result shows the system has the features of low power assumption, fast speed, wireless transitions, high stability and high scalability. In the second scheme, the load cells are used to gauge the strain, UTI is used to convert the analogue signal to digital one, the micro CPU is used to control the system and process the figures, the wireless is used as the transmission way and the results are displayed visually and in real-time. The errors are analyzed theoretically, the test scheme and test results are given too and results are processed to improve the precision. The result shows the system has the features of efficiency, reliability, high precision, which verify the feasibility of the design.