Experimental study of magneto-acousto-electrical tomography based on laser-generated ultrasound technology

In this work, a magneto-acousto-electrial tomography (MAET) method based on laser-generated ultrasound excitation was proposed for high-spatial-resolution images of the impedance of conductive media. Optically generated ultrasound is reported with broad bandwidth and insensitive to electromagnetic interference (EMI). Composite films were used as the optoacoustic sources, which composed of candle soot (CS) and elastomeric polymers. To characterize the laser-generated ultrasonic waves, laser Doppler vibrometer was adopted as the detecting device making the system totally optical while maintaining millimeter-level resolution and detective depths of several centimeter. Photoacoustic waves were then introduced to a sample of different conductivity distribution by laser-generated ultrasound transmitter at one point and detected by a pair of electrodes on the surface of the sample. Due to the absence of EMI between acoustic excitation and magnetic field, the combination of non-electronic ultrasound generator and low-cost, non-invasive MAET have shown its great capacity for effective early tumor assessment.