高分辨小型伽玛相机的数据采集触发电路

摘要

A novel trigger circuit of signal sampling was designed for developing modularized high-resolution compact gamma camera.The design idea is to transfer the peak position detection of the signal of gamma camera into high-precision measurement of pole-zero timing.The unipolar input signal is shaped by a full-pass filter into a bipolar signal.The peak position of signal is determined by measuring the polar-zero position while a trigger pulse is generated corresponding to the peak position.The width and delay of the trigger pulse are adjustable by mono-stable trigger circuits.The pulse is used to trigger the data acquisition system.The experimental results show that the performance of the trigger circuit is stable and reliable.It can provide a high-precision determination of the peak position and well meet the requirements of the high-resolution compact gamma camera.%本文设计了一个数据采集触发电路,把伽玛相机位置读出信号的峰位检测转化为精度高的过零定时测量.该采集触发电路将输入信号全通滤波成形为一个有过零点的双极性信号,检测其过零点的位置检测峰位,产生触发脉冲,由单稳态触发器调节脉冲的脉宽和延时,用于后端数据采集系统的启动信号.实验证明:该触发电路性能稳定,对信号峰位的定时精度高,适用于高分辨小型伽玛相机的模块化开发.