Design and Simulation of Heating Transducer Arrays for Ultrasound-Induced Thermal Strain Imaging

Ultrasound-induced thermal strain imaging (US-TSI) has been proposed as an effective diagnostic modality for atherosclerosis plaque detection. The main challenge of current US-TSI for human subjects is the demand for a very fast temperature rise in a relatively large volume, with appropriate acoustic power that is under the Food and Drug Administration (FDA) safety limit, to cover a major artery such as carotid, and to avoid any physiologic motion artifacts. Therefore, we aim to develop heating transducer arrays with satisfied capabilities in terms of heating volume and speed for US-TSI. By virtue of using symmetrical 3.5 MHz dual 1.5D arrays and applying the dual-focus beamforming approach, the acoustic and thermal simulation results demonstrated that the designed dual heating arrays can induce a 2.1 °C temperature rise within 50 ms in a volume of 2 × 10 × 10 mm
³
(in terms of full width at half maximum, FWHM). The transmitting sensitivity and power conversion efficiency for a single element was estimated to be 14.1 kPa/V and 72.43%, respectively. It showed that the designed dual 1.5D heating transducer arrays can be promising for US-TSI applications.