In medical practice the monitoring of organ and tissue vitality is a critical need in operating rooms as well as in intensive care units (ICUs). The concept of multiparametric monitoring of tissue vitality was described in details in our previous publication. The device, called "Tissue Spectroscope" (TiSpec), contained a single light source (325nm) used as an excitation light. The emitted-reflected light from the tissue was analyzed to provide real-time information on the following three parameters: microcirculatory tissue blood flow, mitochondrial NADH redox state and tissue reflectance. Those 3 parameters represent the main components of tissue O2 balance under in vivo conditions. The 325nm He:Cd laser used was a large bulky and expensive to operate as a critical component in a modern medical device unit. The development of an ultraviolet laser diode by Nichia, Japan, enabled us to replace the light source of the TiSpec with a 390nm laser diode, stabilized by a system developed by Toptica Photonics AG. This change in light source permitted the construction of a second model of the TiSpec, having the following advantages: 1. Smaller in dimensions, 2. Safer in terms of UV radiation effects, 3. Better stabilized for long term monitoring. The new TiSpec was tested in various animal studies as well as in various clinical applications. In order to monitor the brain during neurosurgical procedures, two special fiber optic probes were developed and used. Preliminary studies have shown that the 390nm based TiSpec could be used in monitoring of various organs.