Разработка бесконтактного монитора жизненных показателей человека

Monitoring of heart and lung activity is of vital importance for elderly people and people at risk especially when they are sleeping. Changes in body impedance reflect vital parameters. A measurement system based on electromagnetic induction can monitor these changes. The important benefit is such system requires no contact with human body. A sinusoidal signal (0,1 - 10 MHz) from the signal generator is amplified and feeds the excitation coils and thus generats the excitation field. This field penetrates the body and induces an eddy current. This eddy current leads to a re-induced magnetic field, which superimposes the excitation field. The resulting field is measured by the receiver coils. In this paper the two variants of sensor construction are presented: a transformer and a plain coil. Both of them combine excitation and measurement, and both of them can be used as wearable electronics. The parameters of coils are optimized by resonance frequency and factor of merit. The signal from coil is processed using electronics and microcontroller. The variations of signal are detected with synchronous demodulator and then passed through the low-pass filter. The result of measurement is visualized using computer application. The development should be continued to improve noise rejection and to delete motion artefacts.