微波激励热声信号采集系统

Microwave-induced thermoacoustic signals acquisition system

为了能够成功采集和提取微波脉冲照射生物组织所产生的微弱热声信号,实现对组织的微波热声成像,开发出了一种热声信号数据采集系统。制作了增益105dB、带宽3MHz的可调增益信号预处理器,结合软件设计解决了四通道大数据量保存问题;通过对LabVIEW和C语言进行混合编程实现数字式平均计算,对强噪声背景中的信号进行消噪处理,解决了平均计算过程中的数据漂移问题,这种方法还能够去除奇异信号从而获得更为准确的结果;最后通过实验对微波激励的信号进行采集和分析。实验结果证明本采集系统完全可以满足微波热声成像中热声信号采集的要求,达到预期效果。

In order to acquire the weak thermoacoustic signals that were induced by microwave pulse and realize microwave-induced thermoacoustic tomography of the animal tissue, a new kind of data acquisition system of thermoacoustic signals was developed. The changing gain preprocessor with bandwidth 3MHz and gain 105dB was designed. Combined with a software design the massive data-recording problem of four channels acquisition was resolved. The arithmetic of digital multipoint average was realized through the mix programming both LabVIEW and C language. According to this arithmetic the signals with strong noise background can be de-noised and the results will more precise after removing the singular signal. The data shift problem was also solved successfully in the progress of digital muhipoiut average. Finally, this system was employed to acquire and process the microwave-induced thermoacoustic signals. The experimental results indicate that the signals acquisition system can fulfill the needs of microwave-induced thermoaeoustie tomography very well and meet the anticipation.