Breakthrough wearable device enables practical blood-flow monitoring

Most traditional blood flow monitors use optical fibers to collect the data. These require large lenses and cables, which make the devices fragile and, moreover, introduce subtle vibrations that add noise to the measurements.

To eliminate the need for optical fibers and address the challenges they bring, ICFO researchers Dr. Andrés Quiroga, Dr. Lorenzo Cortese, Dr. Manish Verma, led by ICREA Prof. at ICFO Turgut Durduran, in collaboration with the Fraunhofer Institute for Applied Optics and Precision Engineering IOF and the University College of London, have taken a novel approach by designing a tiny array of micro-objectives that can be mounted directly on a commercial camera chip. This innovation shrinks the entire system while still capturing the same kind of high-quality information as traditional, fiber-based monitors.

The final design, reported in Biomedical Optics Express, is smaller, lighter, and more practical, as it can be placed directly on the skin. As a result, the device is more wearable and easier to use, and could thus be employed to examine the capillary circulation in patients with vascular disease, ensure tissue safety during surgery, or track brain blood flow in newborns more conveniently.

The team tested the apparatus on both lab models and on people, confirming that it works reliably and with high precision. “The system is able to pick up capillary blood flow signals in real time, even detecting the subtle rhythms of the heartbeat,” shares Dr. Andrés Quiroga, first author of the article. In addition, the device can measure tissue blood flow at multiple tissue depths simultaneously, providing a richer picture of circulation. This opens the door to tracking oxygen levels in tissue, an especially valuable insight for clinical care.

With further refinement, the researchers believe their approach could move blood-flow monitoring in tissues beyond the hospital. For instance, the device could be used in sports and wellness for real-time feedback on muscle performance and recovery, or even at home for remote patient monitoring. “Imagine simply putting on a patch or watch-like apparatus that tracks your capillary circulation throughout the day. Doctors could then evaluate remotely whether you are at risk of a stroke due to poor autoregulation,” adds Quiroga. While this application is still hypothetical, the team is now focused on making the technology truly wearable, so it can be used comfortably over long periods and by patients with more complex circulatory conditions.

Reference:

Andres Quiroga, Lorenzo Cortese, Manish Verma, Peter Dannberg, Ilias Tachtsidis, Norbert Danz, and Turgut Durduran, "On-skin, micro-objective enabled camera module for speckle contrast optical spectroscopy/tomography," Biomed. Opt. Express 16, 4091-4103 (2025).

DOI: https://doi.org/10.1364/BOE.571276

Acknowledgements:

Horizon 2020 Framework Programme (688303, 871124, 101016087, 101017113, 101099291, 101099093); European Social Fund Plus; European Regional Development Fund (EFRE-OP 2014-2020 - Project no. 2021 FE 9032); Fundación Cellex; FUNDACIÓ Privada MIR-PUIG; Agencia Estatal de Investigación (PID2019-106481RB-C31/10.13039/501100011033, PID2023-151973OB-I00 PHOTOSHOCK, PID2023-147553OB-I00 SCOSWear, LUX4MED/MEDLUX, PHOTOMETABO); Fundación Carmen y Severo Ochoa (CEX2019-000910-S); Centres de Recerca de Catalunya; Agència de Gestió d'Ajuts Universitaris i de Recerca (2019-FIB-00968, 2022-SGR-01457); Institució Catalana de Recerca i Estudis Avançats (RIS3CAT-001-P-001682 CECH); Departament d'Empresa i Coneixement, Generalitat de Catalunya; National Institutes of Health (R21EB031261).