NONINVASIVE MEASUREMENT OF FOREARM BLOOD-FLOW AND OXYGEN-CONSUMPTION BY NEAR-INFRARED SPECTROSCOPY

We applied near-infrared spectroscopy (NIRS) for the simultaneous meas urement of forearm blood flow (FBF) and oxygen consumption (VO2) in th e human by inducing a 50-mmHg venous occlusion. Eleven healthy subject s were studied both at rest and after hand exercise during vascular oc clusion. FBF was also measured by strain-gauge plethysmography. FBF me asured by NIRS was 1.9 +/- 0.8 ml.100 ml(-l).min(-1) at rest and 8.2 /- 2.9 ml.100 ml-l min-l after hand exercise. These values showed a co rrelation (r = 0.94) with those obtained by the plethysmography. ire, values were 4.6 +/- 1.3 mu M O-2 100 ml(-l).min(-1) at rest and 24.9 /- 11.2 mu M O-2.100 ml(-l).min(-1) after hand exercise. The scatter o f the FBF and ire, values showed a good correlation between the two va riables (r = 0.93). The results demonstrate that NIRS provides the par ticular advantage of obtaining the contemporary evaluation of blood fl ow and VO2, allowing correlation of these two variables by a single ma neuver without discomfort for the subject.