Integrated-Circuit Node for Time-Domain Near-infrared Diffuse Optical Tomography Imaging Arrays with On-chip Histogramming and Integrated VCSELs

Next-generation brain-computer interfaces (BCI) for healthy individuals largely rely on non-invasive functional imaging methods to record cortex-wide neural activity because of the risk associated with surgically implanted devices. Near-infrared (NIR) time-domain diffuse optical tomography (TD-DOT) is a promising non-invasive imaging approach which relies on reduced optical scattering and absorption of the human skull and brain tissue in the NIR spectrum [1]. In TD-DOT imaging, the time-of-flight (ToF) of scattered photons is measured, improving on continuous-wave approaches. This method has the potential to allow for direct sensing of intracellular neural activity and hemodynamics at higher spatial resolutions than electroencephalogram (EEG) and at higher temporal resolution than functional magnetic resonance imaging (fMRI), while supporting more compact and cost-effective form factors.