Open-Source Live-Reconfigurable Multi-Mode Wearable Ultrasound

2026-10-01

AI Summary

This study addresses the high switching latency in multimodal wearable ultrasound and the difficulty of real-time reconfiguration on resource-constrained devices by proposing an open-source sensing transition control stack. By introducing hardware configuration descriptors and shadow register mechanisms to minimize peripheral state update overhead, combined with Wi-Fi 6 host scheduling or MCU firmware loop execution for transition sequences, low-latency online reconfiguration of a 32-channel probe is achieved. Pulsatile flow phantom validation demonstrates that single-switching overhead is reduced to 3.1 ms, with a multimodal repetition rate reaching the theoretical maximum of 90.1%. The system successfully enables concurrent reconstruction of blood flow and structural signals, providing an efficient solution for continuous monitoring applications.

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.

Problem

• wearable ultrasound
• multi-mode reconfiguration
• reconfiguration latency
• time multiplexing
• resource-constrained devices

Innovation

• Wearable Ultrasound
• Live-Reconfigurable
• Transition-Aware Control
• Shadow Registers
• Time-Multiplexing