Device for non-invasive measurement of a dye concentration

摘要

A device for non-invasive determination of the extinction of radiation emitted by at least one radiation source into a peripheral vessel section of a circulatory system, having a radiation detector which receives the radiation and delivers a measurement signal proportional to the radiation intensity, is intended to be improved in that the concentration of a dye introduced into the circulatory system is possible. In order to achieve the object, provision is made that a phase detector (6) and a differentiating component (7) are connected downstream of the radiation detector (5), and the differentiating component (7) delivers as output quantity the gradient of the measurement signal at a predeterminable phase relation, existing between two sequential relative extrema of the measurement signal and resulting from the pulsation, the output quantity being stored in the evaluation unit (8) as a characteristic blood quantity (15) and the associated measurement signal being stored in the evaluation unit (8) as a measured blood value (13) and that, after introducing a predetermined volume of a dye into the circulatory system, a characteristic dye quantity (16) and a measured dye value (14) with the same phase relation with respect to the characteristic blood quantity (15) and with respect to the measured blood value (13) in the evaluation unit (8) are registered, and that a quantity proportional to the concentration CF1 of the dye is formed in the evaluation unit (8) from the ratio of the product of the characteristic dye quantity (16) with the measured blood value (13) and the product of the characteristic blood quantity (15) and the measured dye value (14).