A Study on Estimation Method of Red Blood Cell Aggregation during Extracorporeal Circulation Based on Image Correlation

Abstract

Measurement of blood viscosity is highly desired during extracorporeal circulation treatment. Extracorporeal circulation treatment is considered to be an opportunity for estimating the aggregation degree of red blood cells, which strongly corresponds to blood viscosity, because flow channels have known materials and dimensions. In a flow situation, single red blood cells would easily change their relative positions to each other; however, the relative positions among the red blood cells inside an aggregation would be highly maintained. These phenomena can be optically observed over a transparent blood circuit tube, thus, the aggregation degree of the red blood cells is expected to be obtained by conducting a cross-correlation process between time difference images. The increase of the image-correlation level in accordance with the increase of the aggregation degree was confirmed through experiments.