In vivo photoacoustic imaging of vasculature with a low-cost miniature light emitting diode excitation

In this Letter, we present a photoacoustic imaging ( PAI) system based on a low- cost high- power miniature light emitting diode ( LED) that is capable of in vivo mapping vasculature networks in biological tissue. Overdriving with 200 ns pulses and operating at a repetition rate of 40 kHz, a 1.2 W 405 nm LED with a radiation area of 1000 mu m x 1000 mu m and a size of 3.5 mm x 3.5 mm was used to excite photoacoustic signals in tissue. Phantoms including black stripes, lead, and hair were used to validate the system in which a volumetric PAI image was obtained by scanning the transducer and the light beam in a two- dimensional x-y plane over the object. In vivo imaging of the vasculature of a mouse ear shows that LED- based PAI could have great potential for label- free biomedical imaging applications where the use of bulky and expensive pulsed lasers is impractical. (C) 2017 Optical Society of America