[Measurements of cerebral hemodynamic and metabolic changes by near-infrared spectroscopy]

Near-infrared spectroscopy, a new non-invasive technique, measures changes in the hemoglobin oxygenation state, blood volume, and redox state of cytochrome oxidase (cyt. ox.) in tissues. This technique now finds wide clinical applications, while the specificity and accuracy of the measurement of the redox state of cyt. ox. is still controversial. Recently, we have developed a new approach to measure the redox state of cyt. ox. This method has overcome several technological problems such as difficulty in determination of the in vivo absorption coefficient for cyt. ox. We describe here this new method briefly and the significance of the measurement of the redox state of cyt. ox. in the clinical medicine.