Microwave Acoustic Imaging for Medical Applications

This paper presents an experimental setup of a microwave induced thermoelastic imaging system for medical applications. This system shows unique features that permit noninvasive imaging of biological tissue characteristics which are not sensed by other techniques. Experimental work is reported that demonstrates how the structure of irradiated inhomogeneous media can be identified by detection of the acoustic signal amplitudes induced and their corresponding time delays. This method should be usable down to the VHF region with the advantage of high depth of penetration without decrease in spatial resolution, since the power of resolution depends on acoustic wavelength only. Model measurements at S-band frequencies show a resolution of better than 10 mm and a sensitivity of about 3 mm by applying analog signal averaging (Boxcar integration).