Dual-frequency ultrasound transducer

Abstract

A dual-frequency ultrasound transducer, comprising a piezo-electric element bonded to a substrate, has two resonant vibration modes: a low frequency mechanical bending resonance mode and a relatively high frequency thickness resonance mode. The low frequency bending resonance mode occurs when the piezo-electric element is excited, in use, by a voltage which includes a low frequency oscillating component. The high frequency thickness resonance mode occurs when the piezo-electric element is excited, in use, by a voltage which includes a relatively high frequency oscillating component. The transducer may include a mounting arrangement, such as a support ring securing the periphery of the substrate to an underlying base layer that enhances the depth of penetration and focus of the ultrasound.

Dependencies are inferred from the claim text.