报告题目：Interferometric diffusing-wave spectroscopy for cerebral blood flow monitoring
报告人：Wenjun Zhou 博士
摘要：Though cerebral blood flow (CBF) is a target parameter in neurocritical care, a non-invasive and continuous CBF monitor has remained elusive.Conventional imaging modalities such as Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) are impractical for continuous monitoring, while Transcranial Doppler (TCD) Ultrasound measures velocity, not flow, and can be technically challenging.Near-infrared light technologies to measure CBF in adult humans face a unique challenge; they must sense light fluxes that are both coherent and very weak, returning from deep beneath the surface.The most successful optical CBF technology for the human brain, Diffuse Correlation Spectroscopy (DCS), uses one or more single/few mode photon counting channels, making DCS systems either expensive, or restricted in terms of speed and photon counts.Here, by leveraging a low-cost sensor technology, we built and validated a novel near-infrared light-based (optical) device, called “interferometric diffusing-wave spectroscopy (iDWS)”, which monitors CBF continuously and non-invasively.We achieved this by replacing expensive detectors, currently used for optical CBF monitors, with complementary metal–oxide–semiconductor (CMOS) arrays, widely found in cell phone cameras and other mass-produced devices.This innovation is enabled by an additional optical “trick” known as interferometry, which transforms each CMOS camera pixel into a sensitive detector for fluctuations of weak light that probe blood flow in the deep brain.Since CMOS camera pixels are cheap and numerous, this invention of iDWS can both improve the performance and reduce the cost of optical CBF monitoring.Finally, we believe that iDWS would implicate a potential paradigm shift for optical CBF monitoring and the field of diffuse optics in general.
报告人简介：Dr. Wenjun Zhou received his B.Sc. and M.Sc. degrees from China Jiliang University in 2008 and 2011, respectively, and Ph.D. degree from Carleton University in 2015. He has been working as a postdoctoral fellow in Department of Biomedical Engineering in University of California Davis since 2016.His main research interests include biomedical optics, fiber optics, and plasmonics.He has published 14 first author papers in journals, including Optica, Laser & Photonics Reviews, and Optics Letters.