Optical Blood Clotting Sensor for an Artificial Circulation Apparatus

This paper reports a newly developed micro optical sensor for detecting blood clotting in an artificial circulation apparatus, such as a blood pump. The sensor comprises three LEDs, CMOS chip, which has monolithically-fabricated photodiodes, and amplifier circuits. The small sensor size (2.8×2.8×0.4 mm
³
, after packaging with epoxy resin: 5.5×5.5×1.2 mm
³
) allowed it to be mounted and measure various points of the artificial circulation apparatus. We have evaluated the blood clotting detection performance using porcine blood. Then, we detected blood clotting in a blood pump by analyzing the change in the optical characteristics of blood that lead to clotting using the developed sensor. The micro optical sensor contributes to the development of a blood clotting monitoring system for artificial circulation apparatus.