Spatial and temporal-based diffusive correlation spectroscopy systems and methods

A system comprising:

• a wearable assembly configured to be positioned on a body and comprising:
• a K by L photodetector array comprising a plurality of photodetectors and configured to
• detect light that exits the body at a second location after the light enters the body at a first location different than the second location and scatters within the body, and
• output a plurality of electronic signals representative of the detected light as a function of time, where each photodetector included in the photodetector array is configured to output a different one of the electronic signals;
• an optical spacer attached to a front surface of the photodetector array;
• a pinhole array attached to a front surface of the optical spacer, the pinhole array having a K by L array of pinholes configured to be aligned with the photodetectors, the pinhole array configured to be in physical contact with the body and allow a certain amount of light to be incident upon each of the photodetectors;
• and
• a processor coupled to an output of the photodetector array and configured to
• sample the electronic signals output by the photodetector array at a plurality of delay times during a predetermined time period to generate a sequence of frames each corresponding to a different delay time in the plurality of delay times, where each of the frames includes K times L digital sample values at K by L pixel locations that correspond to locations of the photodetectors within the photodetector array,
• apply a plurality of temporal-based and spatial-based correlation measurement operations to the sample values in each of the frames,
• generate, based on the application of the temporal-based and spatial-based correlation measurement operations to the sample values in each of the frames, a plurality of spatiotemporal correlation measure values for the light detected by the photodetector array, and
• include the plurality of spatiotemporal correlation measure values in a correlation map that corresponds to a predetermined delay time interval that represents a difference between two delay times within the plurality of delay times.