A recent Medgadget article discussed new wearable technology that provides non-invasive optical brain imaging. The device is a helmet called Kernal Flow, and it performs time domain functional near-infrared spectroscopy (aka TD-fNIRS) in a less expensive and complex way than traditional systems. The helmet uses near-infrared light to quantify hemoglobin concentration in several regions of the brain to assess brain activity.
Weighing just 4.4 lbs, the Kernal contains four plates with 52 modules that envelope the cranium. Each module contains two laser sources that create rapid pulses that pass through the scalp and skull to a series of six detectors that record photon arrival times. The helmet still needs some tweaking to account for different hair and skin types, but early tests have been promising. A video demonstration of the Kernal Flow can be seen here.