A human ear-inspired ultrasonic transducer (HEUT) for 3D localization of sub-wavelength scatterers

Abstract

The proposed technology aims to enable 3-D localization of scatterers using single-element ultrasonic transducers, which are traditionally limited to 1-D measurements. This is achieved by designing a bespoke acoustic lens with a spiral-shaped pattern similar to the human outer ear, a shape that has evolved for sound source localization. This lens breaks the surface symmetry of the transducer, allowing ultrasonic waves arriving from different directions to be encoded in a certain way that can later be decoded to extract directional information. By employing the mechanism of spatial-encoding of the received signals and decoding via signal processing, the location of sub-wavelength scatterers can be detected in 3-D with a single measurement for sparsely distributed scatterers. The proposed technology is first verified through a simulation study, and then 3-D printed acoustic lenses are used to demonstrate the 3-D encoding functionality of the Human Ear-inspired Ultrasonic Transducer (HEUT) experimentally. A framework is created to localize scatterers in 3-D by processing received signals acquired by a HEUT prototype. With this technology, a single transducer can obtain multi-dimensional information with a single pulse-echo measurement, reducing the number of elements required for performing 3-D ultrasound localization. The proposed spatial-encoding and –decoding technology can be applied to other wave-based imaging methods to develop affordable, practical and compact sensing devices.

Sevan Harput

Associate Professor in Electrical and Electronic Engineering

Sevan is a Associate Professor in the at Division of Electrical and Electronic Engineering, London South Bank University, where he leads the SPEED Ultrasound Lab. The ultrasound researchlab aims to develop new imaging and sensing technologies using acoustic waves at ultrasonic frequencies.