The Near-infrared spectroscopy (NIRS) is a technology widely used in clinical investigation as an index of brain and tissue oxygenation. The INVOS© Cerebral/Somatic Oximetry is used in high-risk patients or surgeries to provide continuous, real-time, regional oxygen saturation (rSO2. The monitoring parameters, excluding the INVOS©, will be continuously recorded on the software program RugloopII© Waves (Demed, Genk, Belgium).