A Novel Method for Performance Evaluation of Focused Ultrasonic Transducers

The characteristic information about an ultrasonic transducer is generally described by the ultrasonic R/F signal back from a reflector and its frequency characteristics in the data sheet. The information can, however, hardly assure that the focused ultrasonic transducer would produce well-focused sound fields which the performance of the transducer absolutely depend on. Therefore, we propose the measured size of focal spot and the reconstructed shape of effective focal zone in the focused sound field as novel measures for the performance evaluation of the focused ultrasonic transducers. The process of getting the both of the transducers is conducted by the implemented software including sound field scanning and virtual 3D reconstruction functions which requires the echo of a point reflector. The proposed method could effectively distinguish superior ones among many transducers made in the same specification and be also used to detect the performance degradation due to the aging of the transducers.