Intraoperative functional brain imaging - hemodynamic response visualization using Laser Doppler

By using an 808nm laser as illumination, oxyand deoxy-hemoglobin are sampled equally and so, by collecting the Doppler shifted light we obtain information on all the red cells moving in the illuminated tissue, hence we can visualize: Perfusion, Concentration of moving cells and their Speed distribution. At 808nm the light penetration depth is in the millimetre range and so is highly appropriate for imaging the active cortical surface.