The non-invasive device named Diffuse Optical Spectroscopy developed at the Beckman Laser Institute is to be used to measure various physiological parameters. Since mitochondria produce most of the energy necessary for cellular function, their efficacy is most important for systems with a high energy demand like the brain, heart, skeletal muscle, kidney, liver, and endocrine tissues. As a result, mitochondria diseases usually manifest as complex, multi-organ disorders, requiring multispecialty investigations.