A process is disclosed for non-invasively measuring cerebral blood flow by simultaneously determining a blood flow index which is directly proportional to the blood flow. For that purpose, the cerebral flooding dynamics of an intravenously injected indicator dye with absorption properties in the near-infrared spectrum is sensed by near-infrared spectrocopy and the arterial flooding dynamics is sensed by pulse densitometry. A device used to carry out this process consists of a multiple channel apparatus with at least two near-infrared spectroscopes which have two pulsed monochromatic light sources each (with a measurement and a reference wavelength) in the range of the near-infrared spectrum, at least one or several light receivers connected to a photomultiplier, and a non-invasive measurement apparatus for the pulse densitometric determination of the tracer concentration in the arterial blood of the systemic blood circulation.
PROCESS AND DEVICE FOR NON-INVASIVELY DETERMINING CEREBRAL BLOOD FLOW BY NEAR-INFRARED SPECTROSCOPY