Biography
Enrollment Date: 2009
Graduation Date：2012
Degree：M.S.
Defense Date：2012.05.25
Advisors：Hong Chen
Department：Institute of Microelectronics，Tsinghua University
Title of Dissertation/Thesis：Design and Implementation of a Pressure Measurement System in Total Knee Arthroplasty
Abstract:
The number of osteoarthritis patient is increasing with more and more old-age population in China. The knee is the largest flexure joint in human body and it is easy to be damaged because its structure is complex. Total Knee Arthroplasty(TKA) is an appropriate method of treatment to the patient who is still suffering pain of osteoarthritis after other cleaning up surgery.The TKA is an operation to replace the damaged section of knee joint with artificial knee implant. The key point of this surgery is to make sure that the implant is in proper position where its two sides bare balanced pressure, because imbalance of the knee implant will lead to unnecessary abrasion, looseness and dislocation. The dislocation or the looseness will bring new pain to the patient, and will subsequently cause a revision surgery to reduce the pain. So it is important to have a successful one-off operation to avoid the revision surgery, and the key factor of a successful operation is the balance of artificial knee implant.However, doctors rely on experience to place the implants during TKA present, and it is impossible to get the pressure value. A force measurement system is proposed in this paper to meet doctors’ need. This system, applied in the TKA, can measure the pressure and display the pressure in 3D, and assist doctors to adjust the position of implant to make the implant bear balanced pressure and thus enhance the surgery effect.Two kinds of measurement system are proposed in this article. The first kind is called wired system, in which data is transmitted in wired way. Many pressure sensors are adopted to compose sensor array to gather pressure data, and the analog signal of sensor is converted to digital signal. A MCU is used to control the conversion and transmit the data to PC to display the pressure in real time. Test result proved the system has excellent precision and high working speed, and its performance can meet doctors’ need. The second kind is called wireless system, in which data is transmitted in wireless way. This system is designed based on the first kind of system. It adopts the same pressure sensor and ADC. A chip with controller and RF module is used to control the process of data converting and transmitting in wireless way. A receiver is designed to receive the data and convey the received data to PC for demonstration. Test result shows the circuit performance is outstanding. The precision and the speed all meet doctors’ demand. The power is low-power, and can be powered by battery. Transmission data in wireless way can avoid the wire causing influence on doctor’s operation. The distribution of procedure can be displayed in 3D and real-time. The doctor can review the process of the TKA with pressure data saved during the operation by the system. The wireless system makes substantial optimization compared to the wired system, and takes a solid step on the way towards final production.