Detection of periodic micro movements of the head using a flat sensors system

A device for the frequency measurement of micromovements of the head is described. The system uses two flat eddy current proximity sensors. They are included in oscillators whose frequencies are a function of target sensor distance. The first sensor realizes the head micromovements measurement. The second one eliminates the breathing movement. A set of about one hundred tests on healthy subjects shows that a periodic micromovement of a mean frequency of 9.7 cycles a minute is detected.<
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