Real-time processing of coded photoacoustic signals

Abstract

Photoacoustic imaging (PAI) combines the contrast of optical imaging methods with ultrasound resolution. For inexpensive and small PAI systems, laser diodes are beneficial. Photoacoustic coded excitation (PACE) was demonstrated to enhance the signal-to-noise ratio in certain laser-diode-based settings. These settings were constructed for offline use. Here, we present an approach to laser diode based imaging with up to one frame per second employing three different PACE code sequences in an online setting: Golay codes, Legendre sequences, and difference set codes. The system performance is characterized for different code lengths, pulse repetition frequencies, and imaging depths. The performance for the three PACE code sequences is compared. © 2012 by Walter de Gruyter Berlin Boston.