Simultaneous Measurement of a Blood Flow and a Contact Pressure

Although a number of laser Doppler blood flow sensors have been developed over the past few decades, they remain uncommon in practice. This is because the contact pressure between the skin and the sensor is not measured simultaneously with blood flow, despite the fact that blood flow is greatly affected by contact pressure. Thus, reliable and highly reproducible measurement of blood flow could not yet be realized. In addition, changes in beam conditions or body temperature also have an effect on blood flow measurement. Therefore, we fabricated a micro electro mechanical system (MEMS) blood flow sensor which can measure contact pressure, beam power, and body temperature, for reliable and highly reproducible measurement.