Abstract
This paper discusses a real time measurement of the rigidity of the red blood cell in the microchannel using a high speed vision system. We focus on the passing time and the length of the cell in the narrow channel as indexes of the rigidity of the cell. The most important advantage utilizing a high speed vision system is that we can see and confirm what is happening in the microchannel while a red blood cell is passing. In the algorithm of the measurement, we check whether a red blood cell is recognized correctly in the channel, and save the only successful data.