Associate professor of Biomedical Engineering and Ophthalmology at the University of California, Davis
Human Brain Interferometers for Better Blood Flow Monitoring
Steady cerebral blood flow (CBF) is needed for normal brain function, but continuous monitoring of CBF in humans is currently challenging. Here, by leveraging a low-cost sensor technology, we introduce a class of novel near-infrared optical devices that monitor CBF continuously and non-invasively in adult humans. We achieve this by replacing expensive single photon counting detectors, currently used for optical CBF monitors, with complementary metal–oxide–semiconductor (CMOS) arrays. We maintain performance by employing an additional optical “trick” known as interferometry, which transforms each CMOS pixel into a sensitive detector for fluctuations of coherent light that probes blood flow in the brain. Our method is called interferometric Diffusing Wave Spectroscopy (iDWS). Since CMOS camera pixels are cheap and numerous, iDWS both improves the performance and reduces the cost of optical CBF monitoring, enabling record brain-to-scalp sensitivity. By liberating CBF monitoring from photon counting, iDWS enables measuring CBF continuously in a new environments. In this talk we describe technical advantages of iDWS relative to conventional methods, and broadly envisage how interferometry can help to advance the field of diffuse optics.
Vivek Srinivasan is Associate Professor of Biomedical Engineering and Ophthalmology and Chancellor’s Fellow at UC Davis. His group develops new light-based technologies for in vivo imaging and sensing of the brain and eye. Starting with a firm grounding in neurophysiology and biomedical engineering, his group employ ideas novel photonic technologies and approaches to accomplish this goal.
For more information or to schedule a meeting with the speaker, please contact Xandra Dvornikova.
Sponsored by the Berns Family Laser and Microbeam Program
Hosted by: Dr. Bernard Choi