Abstract
An unconstrained ECG and heart rate monitor is designed using ECG measured at bathtub. The apparatus is consisted of an analog and a digital parts. In the analog part the ECG wave from electrodes which are fixed inside bathtub is amplified approximately 4000 times. In the digital part the heart rates are calculated from the R-R interval of ECG pulse and the calculated data are stored in random access memory. The stored data in this apparatus are transferred to a personal computer by the RS-232C interface and analyzed by the personal computer. The heart rates obtained from bathtub ECG agreed with those obtained from body surface ECG. In measurement of bathing water with several concentrations of sodium chloride solution, the amplitude of ECG wave form decreased as an increase of electrical conductivity. Using this apparatus the heart rate can be obtained easily and noninvasively. Thus this developed monitor can be used as a home health monitor.
