A New Method of Measuring Stimulation Threshold

Abstract Louis Lapicque introduced the hyperbolic stimulation law with the key parameters “rheobase” and “chronaxie” that were obtained with rectangular current pulses. With rectangular pulses rheobase cannot be measured. It was found recently that hyperbolic stimulation rules are also valid for non-rectangular pulses and that their rheobase or chronaxie values are identical with that of their rectangular counterparts. Threshold measuring with exponential pulses allow for determining rheobase directly and chronaxie by calculation with only two measurements. The measuring procedure is described in detail.