A Light-Adjustable Hand-Held Probe for Photoacoustic Tomography in vivo

A light-adjustable illumination scheme for hand-held probe for photoacoustic tomography is presented in this paper. The overall size of the probe is 120 × 60 × 40 mm
³
, which is easy to be held. Compared with traditional photoacoustic probe design, it has the following advantages: (1) Different excitation modes, that is, the different relative position between laser illumination area and ultrasonic detection area, can be selected as needed by tuning control parameters. (2) The spot-adjustable unit (SAU) specifically designed for beam expansion. (3) Angle Adjustment Unit (AAU) based on gear drive is proposed with single power input and bilateral output. Just by adjusting the motor parameters, the purpose of adjusting the incident angle can be precisely achieved. We built a PAT system based on our newly designed apparatus. Phantom and in vivo experimental results show that a variety of lighting schemes can be quickly generated according to requirements without changing the external settings, compared with the conventional probe.