Fast 3-D Opto-Acoustic Simulation for Linear Array With Rectangular Elements

Simulation involves predicting the responses of a physical system. In this article, we simulate opto-acoustic signals generated in a 3-D volume due to the absorption of an optical pulse. A separable computational model is developed, which splits processing into two steps, permitting an order-of-magnitude improvement in computational efficiency over a nonseparable model. The simulated signals represent acoustic waves, measured by a probe with a linear transducer array, in a rotated and translated coordinate frame. Light is delivered by an optical source that moves with the probe's frame. Spatiotemporal impulse response for rectangular-element transducer geometry is derived using Green's function solution to the acoustic wave equation. The approach permits fast and accurate simulation for a probe with an arbitrary trajectory, which is useful for modeling freehand acquisitions. For a 3-D volume of n
³
voxels, computation is accelerated by a factor of n. This may potentially have application in opto-acoustic imaging, where clinicians visualize structural and functional features of biological tissue for assessment of cancer and other diseases.