EFFECT OF VIBRATIONS WITH 2 DIFFERENT AMPLITUDES ON THE ECG

The ECG response of a human body exposed to vertical vibrations was in vestigated. The per cent normalized difference (PND) between the R-wav e amplitude before and after vibrations was monitored. Results obtaine d from a representative subject show an oscillatory decay of the PND b ehaviour with time. This behaviour can be modelled as a linear second order damped system. The natural frequency, damping ratio and the reco very time of the cardiac system can be measured.