Human Pulse Detection Using Multiple Silicon Microphones toward Estimation of Physical Condition

An Electret Condenser Microphone (ECM) fabricated by Micro Electro Mechanical System (MEMS) technology, or a silicon microphone chip, was integrated into a multiple sensor apparatus to detect human pulse wave towards the estimation of physical condition of the body. A number of ten MEMS-ECMs were placed at the forearm of a subject with multi-channel signal amplifier and recorder. As a developing result, it is successfully demonstrated that MEMS-ECM sensors are sensitive enough to detect human pulse wave. Moreover, it is suggested that an internal physical condition in relation to an activity of sympathetic/parasympathetic nervous system might be estimated by comparing pulse signals derived by this multiple MEMS-ECM sensors.