An anonymous reader writes: Grad students at UC Irvine have built a spatial frequency domain imaging system using parts from a cheap LCD projector and a digital camera. The system can be used to check the level of bruising or oxygenation in layers of tissue that aren't visible to the naked eye, according to an article in Chemical and Engineering News. An accompanying video shows the series of patterned pulses that the improvised imaging system makes in order to read hemoglobin and fat levels below the surface of the skin. A more sophisticated version of the imaging system is being commercialized by a startup within UC Irvine, called Modulated Imaging. The article and video also describe infrared brain scanners that can non-invasively check for brain bleeds, and multiphoton microscopes that produce stunning images of live skin cells.