It is a technological difficulty to acquire data from ultrasound with ultra-band in the study of microwave-induced thermoacoustic tomography. A high-speed data acquisition system for the ultrasonic signal with a frequency fewer than 500 MHz is designed in the paper. The result obtained demonstrates that the system holds good for microwave-induced thermoacoustic tomography.

The instrument is com posed of such components as SCM,pressure sensor,electric pump,magnetic valve and sleeve-type gasbag.It can control the hemostatic pressure,hemostatic time and slack time automatically.So the ischemic necrosis can be avoided thoroughly thr ough it.With the small volume,light weight,low power consumption and convenient operation,the instrument is fit for emergency treatment of mass casualties.

In this experiment, the complex-permittivities at 2 450 MHz of distilled water and various NaCl solutions were measured separately, and acquired data were analyzed and amended. The system develooped on the basis of this experiment is of great significance to studying the measurement of complex-permittivities of high-loss biologic tissues by perturbational method.
Chemistry Techniques, Analytical ; Sodium Chloride ; chemistry ; Solutions ; Water ; chemistry