Positron Emission Tomography Scanner (pet) In Electrical And Mechanical Control System

Positron emission tomography (PET) is the functional imaging equipment with good specificity among the modern nuclear medicine instruments. It can make the noninvasive diagnosis of coronary artery disease (CAD), brain disease and tumor in their early changes. Therefore, it plays a very important role in the field of modern medicine. Based on the introduction of the systematic structure and working principle of PET, the thesis mainly described the realization of the partial function in the mechanical and electrical control system. Furthermore, the thesis referred the design of a new circuit of fan-out of high frequency clock.In the first and second parts of this thesis, the characteristics, working principle and mode designs of the PET system were described with the emphasis on the special functions of PET comparing with other nuclear imaging equipment.The third part stressed on the design of gantry control print circuit, especially on how to use AM85C30 to expand serial port and to realize the master-slave mode multi-point bus serial communication system with the principle gantry control circuit and other subordinate circuits using RS-485 bus standard. We developed an idea of more tasks and non-occupancy in programming to make sure that the circuit can complete the communication between the gantry control circuit and other circuits within the permissible minimum time in the system.A new circuit of fan-out of high frequency clock was designed to providea reference clock for the front electrical mode of PET system in the fourth' part of the thesis. The circuit performed the division and fan-out of highfrequency clock by using FPGA, and transformed the clock in LVDA stylewith least disturbance as possible. At the same time, it reduced the delay difference between clocks.In the last part of this thesis, various electrical noises generated in the system were analyzed and the efficient measurements to improve the anti-interference feature on both hardware and software were employed to keep the stable operation of the system.