Flow uses infrared light to measure localized changes in blood oxygenation of the cortex. Our spatial resolution is in-line with other optical systems, which brings it in around 1cm [reference: White BR, Culver JP. Quantitative evaluation of high-density diffuse optical tomography: in vivo resolution and mapping performance. J Biomed Opt. 2010;15(2):026006. doi:10.1117/1.3368999]. We are working to complete a phantom study to answer this using a standardized method. We'll publish full details of our analyses early next year. As for time resolution, we collect histogram measurements at 200 Hz. Time multiplexing considerations to avoid cross-talk will determine the update rate for imaging the whole head.