Method and apparatus for detecting hemolysis or for determining a correction factor to correct the influence of hemolysis on a measurement of hematocrit
A method and an apparatus for detecting hemolysis or for determining a correction factor for correcting the influence of hemolysis on the hematocrit measurement, and an extracorporeal blood treatment apparatus with a device for detecting hemolysis. The invention is based on the implementation of two different optical measuring methods for determining hematocrit, wherein the hemolysis or the correction factor is established on the basis of the hematocrit values as detected by the two measuring methods. It has been found that the hematocrit values detected by the different measuring methods show that they are influenced with different intensity by the increasing concentrations of free hemoglobin in plasma consequent to hemolysis. A preferred embodiment envisions a reflection measurement as a first measuring method and a transmission measurement as a second measuring method. Detecting the hemolysis or establishing the correction factor is then achieved on the basis of forming the difference between the hematocrit values in the reflection and the transmission measurements. The apparatus includes a computing and analyzer unit 16 that is configured such that the hemolysis or the correction factor is established on the basis of the value as detected for hematocrit according to the first and the second measuring methods.
