For the evaluation of the blood flow will be used the Laser Doppler Fluxometer (LDF) equipped with an infrared emitting diode laser (VMS-LDF2 DUAL CHANNEL- Laser Doppler Blood Flow and Temperature Monitor, trademark Moor instruments- FAPESP process number is 2012 / 13331-2). The maximum power of the diode laser is 2.5mW, emitting wavelengths in the order of 785nm ± 10nm. The time constant will be set to 0.1s and the bandwidth to 15kHz. It will be used 2 probes composed of 2 optical fibers of 0.25mm each, conditioned in an all steel of 1.5mm. The probes will be calibrated monthly in a solution that comes with the equipment kit.