Continuous ambulatory monitoring of peripheral vascular perfusion could enable earlier detection of vascular dysfunction in individuals with diabetes mellitus and more timely management of cardiovascular disease. Clinical imaging modalities provide high-fidelity vascular information but are impractical for ambulatory use, whereas most wearable devices are limited to single-modality sensing and do not provide imaging. Electrical bioimpedance has the potential to bridge this gap by enabling rapid spatial and temporal imaging while remaining sensitive to hemodynamic changes. Here, we introduce a wearable ring with 8 electrodes and 32-channel bioimpedance sensing for finger blood flow imaging. In 96 healthy participants measured at rest and during autonomic maneuvers, we resolve conductivity images in the digital arteries associated with pulsatile blood flow and train neural network models for continuous cuffless blood pressure waveform estimation. We demonstrate the feasibility of bioimpedance imaging in a ring form factor, supporting its potential for ambulatory cuffless hemodynamic monitoring.
@article{arxiv.2604.14494,
title = {A wearable electrical hemodynamic imaging ring},
author = {Gia-Bao Ha and Lucas Takanori Sanchez Shiromizu and Jaehyeon Song and Zhuyun Xie and Henry Crandall and Dinali Assylbek and Alexandra Boyadzhiev and Huanan Zhang and Fernando Guevara Vasquez and Ramakrishna Mukkamala and Michael Widlansky and Shamim Nemati and Jesse Capecelatro and C. Alberto Figueroa and Benjamin Sanchez},
journal= {arXiv preprint arXiv:2604.14494},
year = {2026}
}