Technical Note: Compact thermoacoustic imaging system based on a low-cost and miniaturized microwave generator for invivo biomedical imaging.

Abstract

Most of existing thermoacoustic imaging (TAI) studies generally utilized a linear modulator-based high peak power magnetron generator (MG) for efficient TA signal excitation. However, a linear modulator-based MG is bulky and expensive. Here we present a low-cost and compact thermoacoustic imaging (TAI) system based on a miniaturized MG. The MG is based on solid-state modulator and operates at 3.05±0.025GHz, with a peak power of up to 60kW and adjustable pulse duration from 70 to 600ns. The dimensions and weight of this MG are 350×210×70mm3 (Width×Length×Height) and 7.5kg, respectively. The spatial resolution of the miniaturized MG-based TAI system is determined to be from 0.3 to 1.4mm using controlled phantom experiments. The system is further evaluated using invivo experiments where the finger joints and vasculature in the forearm and opisthenar of human participants are successfully imaged. This study suggests that the miniaturized MG based TAI systems can be used for invivo joint and vascular imaging with multiscale resolutions (0.3-1.4mm).