Low cost and high-power LED’s are replacing highly expensive and bulky Lasers in photoacoustic imaging (PAI) technology. LEDs bring the opportunity to image samples at a higher repetition rate (in kHz) compared to the conventional Q switched lasers (typically upto 20 Hz) and thus offer high frame rate and averaging power while maintain real-time imaging capability. In order to make a complete switch from Laser to LEDs, a proper understanding of this newly emerging class of LED arrays is important, for e.g., beam divergence, beam focus, coherence, time-dependent power and wavelength stability, penetration depth and sensitivity, etc. We performed characterization and optimization experiments on different tissue mimicking phantoms with various optical scattering and absorbing properties using a commercially available AcousticX PAI system with customized 3D printed holders for the LED array. The axial and lateral positions of LED arrays with respect to the acoustic probe to image deep lesions upto 1.5 cm were optimized. We also report the sensitivity of the system and Signal-to-noise-ratio (SNR) dependency of the LED arrays’ axial and lateral positions. Finally, we also demonstrate the adaptability of our custom designed, 3D printed variable angle and distance holder to perform deep tissue ultrasound and photoacoustic imaging probe on phantoms of with absorbers at different depth and in subcutaneous tumors and compare it with traditional laser based photoacoustic imaging systems.
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