Venous saturation and blood flow behavior during laser-induced photodissociation of oxyhemoglobin

The value of relative oxyhemoglobin concentration (saturation) in arterial (SаO 2 ) and venous blood (SvO 2 ) plays a significant role in the oxygen exchange in tissue and is used as criterion of delivery of oxygen adequate to the needs of tissue cells. Reduction of the volume of blood flows as well as reduction of oxygen concentration in arterial blood causes hypoxia - deficit of oxygen in tissue. One of the main mechanisms of elimination of hypoxia is based on compensation of the oxygen deficit by increasing the oxygen extraction from arterial blood, which leads to reduction of oxygen in the venous blood 1 . In this report two optical techniques for measurement of venous blood saturation are presented. The first one is based on the pulseoximetry with artificial mechanical modulation of the tissue volume and the second one on the spectrophotometry of human respiratory rhythm. Good correlation between the results obtained with both techniques is observed.