[R-wave selector recognizing signals by geometric characteristics]

Many up-to-date cardiologic units show poor information reliability when the subject moves. The noise immunity of the units can be considerably improved by means of the R-wave selector that discriminates signals by rate and duration of the pulse decay (RS-slope). Two versions of the circuitry for such units are possible, parallel and series. The noise immunity of both versions is similar, but the series one may be easier realized. The optimum threshold values for this selector are as follows: 12 ms in the rate and 14 ms in the duration.