title: Speckle contrast optical spectroscopy, a non-invasive, diffuse optical method for measuring microvascular blood flow in tissue.
abstract: We introduce a new, non-invasive, diffuse optical technique, speckle contrast optical spectroscopy (SCOS), for probing deep tissue blood flow using the statistical properties of laser speckle contrast and the photon diffusion model for a point source. The feasibility of the method is tested using liquid phantoms which demonstrate that SCOS is capable of measuring the dynamic properties of turbid media non-invasively. We further present an in vivo measurement in a human forearm muscle using SCOS in two modalities: one with the dependence of the speckle contrast on the source-detector separation and another on the exposure time. In doing so, we also introduce crucial corrections to the speckle contrast that account for the variance of the shot and sensor dark noises.
authors.affiliation: ICFO-Institut de Ciències Fotòniques, Av. Carl Friedrich Gauss, 3, 08860, Castelldefels, Barcelona, Spain ; These authors contributed equally to this work.
authors.forename: Claudia P
authors.initials: CP
authors.lastname: Valdes
authors.affiliation: ICFO-Institut de Ciències Fotòniques, Av. Carl Friedrich Gauss, 3, 08860, Castelldefels, Barcelona, Spain ; These authors contributed equally to this work.
authors.forename: Hari M
authors.initials: HM
authors.lastname: Varma
authors.affiliation: ICFO-Institut de Ciències Fotòniques, Av. Carl Friedrich Gauss, 3, 08860, Castelldefels, Barcelona, Spain.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Kristoffersen
authors.affiliation: ICFO-Institut de Ciències Fotòniques, Av. Carl Friedrich Gauss, 3, 08860, Castelldefels, Barcelona, Spain.
authors.forename: Tanja
authors.initials: T
authors.lastname: Dragojevic
authors.affiliation: Department of Radiology, Washington University School of Medicine, St. Louis, MO 63130, USA ; Department of Physics, Washington University, St. Louis, MO 63130, USA.
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Culver
authors.affiliation: ICFO-Institut de Ciències Fotòniques, Av. Carl Friedrich Gauss, 3, 08860, Castelldefels, Barcelona, Spain.
authors.forename: Turgut
authors.initials: T
authors.lastname: Durduran
keywords: (170.1470) Blood or tissue constituent monitoring; (170.6480) Spectroscopy, speckle; (170.7050) Turbid media