3D photoacoustic imaging using Hadamard-bias encoding with a crossed electrode relaxor array.

A novel 3D photoacoustic imaging technique is experimentally demonstrated using a 64×64 element bias-sensitive crossed-electrode relaxor array. This technique allows for large 2D arrays to receive across all elements while using minimal channel counts. Hadamard-bias patterns are applied to column electrodes while signals are measured from row electrodes. Photoacoustic signals are measured from a crossed-wire phantom in an intralipid scattering medium. The Hadamard-bias-encoded imaging scheme showed a signal-to-noise (SNR) of 25.3 dB, while the single-column biasing strategy (or identity-matrix-bias pattern) showed a SNR of 8.8 dB.