Ultrafast Orthogonal Row–Column Electronic Scanning (uFORCES) With Bias-Switchable Top-Orthogonal-to-Bottom Electrode 2-D Arrays

Abstract

Top-orthogonal-to-bottom electrode (TOBE) arrays, also known as row-column arrays, have shown great promise as an alternative to fully-wired 2D arrays, owing to a considerable reduction in channels. Novel imaging schemes with bias-switchable TOBE arrays were previously shown to offer promise compared to previous non-bias-switchable row-column imaging schemes and compared to previously-developed Explososcan methods, however, they required significant coherent compounding. Here we introduce Ultra-Fast Orthogonal Row-Column Electronic Scanning (uFORCES), an ultrafast coded synthetic aperture imaging method. Unlike its FORCES predecessor, uFORCES can achieve coherent compounding with only a few transmit events and may thus be more robust to tissue motion. We demonstrate through simulations that uFORCES can potentially offer improved resolution compared to the matrix probes having beamformers constrained by the paraxial approximation. Also, unlike current matrix probe technology incorporating microbeamforming, uFORCES with bias-switchable TOBE arrays can achieve ultrafast imaging at thousands of frames per second using only row-and column addressing. We also demonstrate experimental implementation of uFORCES using a fabricated 128×128 electrostrictive TOBE array on a crossed 25 µm gold wire phantom and a tissue mimicking phantom. The potential for improved resolution and ultrafast imaging with uFORCES could enable new essential imaging capabilities for clinical and pre-clinical ultrasound.

High-Voltage Bias-Switching Electronics for Volumetric Imaging Using Electrostrictive Row–Column Arrays

“…Future work should also aim to improve B-scan imaging frame rates with sparse synthetic aperture schemes. Finally, our ultra-fast FORCES methods have the potential to outperform state-of-the-art MATRIX probes with integrated micro-beamformers since our approach can achieve transmit and receive focusing everywhere in the scan plane, whereas MATRIX probes cannot [7]. Future work should further explore these opportunities.…”

“…As shown in [7], there is potential for our technology to outperform matrix probes with microbeamformers. Our TOBE arrays can achieve synthetic aperture imaging with focusing in transmit and receive everywhere in-plane, while matrix probes often use weakly focused or unfocused transmissions and thus compromise resolution.…”

“…Wiring becomes unwieldy for fully-connected 2D arrays with large channel counts. Matrix probes with integrated micro-beamformers represent state-of-the-art but these use beamforming approximations that can result in degraded inplane performance [4]- [7]. Moreover, these Matrix probes are complex, may require active cooling, are not easily scalable, and are not yet capable of advanced ultrafast imaging modes.…”

Optimal Design of Sparse Matrix Phased Array Using Simulated Annealing for Volumetric Ultrasonic Imaging with Total Focusing Method

“…Similar to the 2D ultrasonic TFM imaging with linear phased arrays, the application of sparse probes can be considered for the volumetric case. Although sparse matrix phased array configuration determination is a hot topic in medical imaging [ 17 , 18 , 19 , 20 , 21 ], it has not been considered in the field of nondestructive testing and TFM imaging. Determination of the sparse array configuration can be regarded as the optimization problem, which can be solved using stochastic optimization methods.…”

Transparent Dual-Frequency CMUT Arrays for Photoacoustic Imaging

“…Capacitive micromachined ultrasound transducers (CMUT) are another type of ultrasound transduction devices which demonstrate wider bandwidth with similar sensitivity compared to their piezoelectric counterparts. Unlike piezoelectric transducers, CMUT are bias-sensitive and bias-switchable, which can enable bias-coded imaging schemes [16], [17], [18], [19]. CMUTs also offer more flexibility in terms of design and material selection, making them a great candidate for developing transparent ultrasound transducers.…”