The Measurement of Blood Coagulation Process in Extracorporeal Circuit Using LED Photoacoustic Imaging

Blood coagulation is measured by using a pressure sensor in a blood circuit, but it is not quick responsive because it is detected by pressure rise caused by coagulation. In this study, we have investigated a method to detect blood clotting at an early stage using photoacoustic imaging, which is thought to be more sensitive. The LED with a wavelength of 850 nm was used as a photoacoustic light source. An ultrasonic wave generated by thermal expansion of mouse blood sealed in a microtube was observed, and also many ripples were observed with time and the coagulation of blood progressed. It was also observed that the waveform considered to correspond to coagulation of blood broadens with time. It was found from the above that there is a possibility that the state of blood clotting can be observed from outside the circuit of the extracorporeal circulation device by using the LED as a light source