Accurate prediction of transmission through a lensed row-column addressed array

Using a diverging lens on a row-column array (RCA) can increase the size of its volumetric image and thus significantly improve its clinical value. Here, a ray tracing method is presented to predict the position of the transmitted wave so that it can be used to make beamformed images. The usable transmitted field-of-view (FOV) is evaluated for a lensed 128 + 128 element RCA by comparing the theoretic prediction of the emitted wavefront position with three-dimensional (3D) finite element simulation of the emitted field. The FOV of the array is found to be 122 +/- 2 in the direction orthogonal to the emitting elements and 28.5 degrees-51.2 degrees, depending on depth and element position, for the direction lying along the element. Moreover, the proposed ray tracing method is compared with a simpler thin lens model, and it is shown that the improved accuracy of the proposed method can increase the usable transmitted FOV up to 25.1 degrees. (c) 2022 Acoustical Society of America.

Automated summary

A ray tracing method is proposed to predict the position of the transmitted wave in order to improve the usable transmitted field-of-view (FOV) of a row-column array (RCA) with a diverging lens. The method is compared with a simpler thin lens model and shown to increase the usable transmitted FOV.