剂量电离室数字滤波器设计

摘要

为满足上海先进质子治疗装置治疗头中剂量电离室电子学A／D转换后的数据率和降噪要求，提出一种多级级联的数字滤波器结构。本文中设计LMS自适应滤波器来滤除50 Hz的工频噪音，相比于传统数字陷波器，不会对有用信号造成损失。通过MATLAB软件仿真对信号处理结果表明，电子学延时减少到170μs，数据率50 kHz，基本符合量化后的剂量数据处理要求。%In order to reduce the data rate and noise after the A /D converter in the electronic system of beam flux ionization chambers , this paper designs a implementation scheme of poly -stage-decimation filter .Com-pared with traditional digital band -stop filter, LMS adaptive filter is used to eliminate the interference of 50 Hz.The benefit of this is to cause no loss of the useful signal .The theoretical simulation with MATLAB show that the delay time of electronic system is reduced to 170 microsecond , at the same time , the data rate is 50 kHz .