Fig. 1.
Conceptual illustration of mDCS measurement. Coherent light is coupled into a scattering medium (a), and collected by one or more single-photon detectors. The photon statistics of the speckle pattern (b) are stored for the duration of an integration time, and analyzed to produce a temporal correlation curve (c). After fitting the data to an expected behavioral model, the average correlation time τc is estimated. Changes to τc can be directly attributed to, for example, a change in blood flow. Note that (b) represents a speckle pattern from a multipixel array, whereas DCS systems have conventionally utilized one detector.