Online Self Adaptive Calibration Front-end Electric Design for a high resolution MicroPET

An Online Self Adaptive Calibration Front-end Electric Design Front-end Electronics Design was presented. For our complex electric system, we need deal with many tasks, such as pileup event calibration, baseline calibration, uniform PMT outputs, etc. A finite state machine(FSM) design describes such different tasks relationships is not an archipelago either, but rather a tightly coupled structure of classes or class hierarchies, which significantly decrease complication of electronic design; Under the help of circuit modeling, an online closed-loop feedback baseline calibration method has been established, which would overcome the disturbance caused by the system temperature changes, and the pre-amplifier’s input bias current or output voltage offset; To avoid to degradation image quality and image distortions caused by pileup events, A pileup calibration method is used to solve the pileup problem and recover the events at very high count-rate; by adjusting the preamp gain at real-time, it becomes easier to uniform the output from photomultiplier tubes. Such design is being applied to our animal PET. Our preliminary results showed: application of FSM design tool to our MicroPET electric design could significantly decrease complication of electronic design. And finally increase the adaptable and robust ability of our MicroPET. With the temperature range from 32.9°C to 47.9°C, the gain of amplifier does not show any significant variation with temperature, such variable gain range is below 1%, which is a sufficiency proof of good stability with temperature for our Front-end Electronics; The energy resolution of
¹³⁷
Cs improved from 31.4% to 19.8% by adaptive self-calibration.