Wearable ultrasound enables faster switches between imaging modes
Open-Source Live-Reconfigurable Multi-Mode Wearable Ultrasound
Hardware Architecture
Summary
Wearable ultrasound devices can look inside the body continuously, but switching between different ways of imaging (like measuring blood flow or tissue structure) usually takes time and slows things down. The authors created a software control system that helps the device change settings much faster during use by remembering what’s needed for each mode and updating only the differences. They tested this on a small ultrasound probe and showed it can switch modes almost three times faster than before, allowing smoother mixed imaging during monitoring.
What this means in practice
- •For medical device engineers: Design wearable ultrasound tools that switch imaging modes quickly during patient monitoring without long delays.
- •For portable health monitoring teams: Enable continuous, mixed-mode ultrasound monitoring of blood flow and tissue structure with minimal latency on compact devices.
Authors
Cédric Hirschi, Federico Villani, Luca Benini, Andrea Cossettini
Abstract
Wearable ultrasound enables continuous deep-tissue monitoring, and a single programmable probe can operate in multiple complementary modes, such as structural A-mode and Doppler flow measurement. However, each operating mode requires dedicated measurement parameters and peripheral states, with no single configuration serving all modes on resource-constrained devices. Time multiplexing of operating modes introduces reconfiguration latency that lowers the effective mode repetition rate. To address this limitation, we present an open-source, transition-aware control stack for low-latency, in-session reconfiguration of the 32-channel TinyProbe wearable platform. Operating modes are described as hardware configurations, and host-side shadow registers track the peripheral states, enabling transition-specific register updates. Transition sequences are executed either by the host (over Wi-Fi 6) or by a firmware loop on the probe MCU. We validate the stack on a pulsatile-flow phantom by interleaving blocks of 25 to 100 pulsed-wave Doppler shots at 1.43 kHz PRF with single 16-channel A-mode acquisitions, changing channel configurations at every transition. Compared to full reconfiguration, the overhead per transition decreases from 30.2 ms to 11.6 ms (host-scheduled) and 3.1 ms (MCU-scheduled). For 75-shot Doppler blocks, the multi-mode repetition rate reaches 16.0 Hz (MCU-scheduled), 90.1% of the theoretical maximum of 17.7 Hz. Concurrent reconstruction of a Doppler spectrogram and a lumen-diameter trace demonstrates the functionality of time-multiplexed flow and structural monitoring.