Development of a Handheld Scanning Transducer Probe for Ultrasound Imaging

Abstract

The scanning transducer technique is a simple and cost effective approach to achieve ultrasound imaging. By mechanically scanning a single-element transducer with a motor stage, the time-variant ultrasound field at an array of locations can be recorded for image reconstruction. When compared with the use of conventional transducer arrays, the scanning transducer approach requires much less data acquisition electronics. However, conventional x-y motor stages used for scanning the transducer are complex, bulky and slow. As a result, the scanning transducer technique for image acquisition has been mainly limited for lab use and is not suitable for handheld imaging applications.

The goal of this research is to achieve a new 2-axis scanning transducer probe for handheld ultrasound imaging operations, which is compact and light-weight. The approach is to develop and capitalize upon a miniaturized water-immersible 2-axis electromagnetic actuator to enable fast and agile scanning of a single-element transducer in a liquid filled probe case.

The design and fabrication of a water-immersible 2-axis electromagnetic actuator has been achieved and its mechanical scanning performance has been characterized and optimized with finite-element simulation. Preliminary pulse-echo imaging experiments were performed to verify its ultrasound imaging capability with scanning in B-scan mode in multiple directions. The scan system built can be dynamically reconfigured to either 1D- B-Scan or even 2D C-Scan formats for conventional 2D as well as 3D ultrasound imaging. In addition, integrated optical light delivery with optic fiber cables was also investigated to extend its capability for photoacoustic imaging.