Rheobase
The rheobase (from ancient Greek ῥεῖν rhein , German 'flow' ) is the lowest electrical stimulus strength, both the voltage and the current strength proportional to this in long-term stimuli, in which a nerve or a muscle triggers an action potential . A long stimulus impulse (for example 1000 ms) is used to determine it, which compared to the duration of an action potential can be regarded as direct voltage and direct current.
The minimum time that a stimulus with twice the rheobase strength has to last in order to still have an exciting effect is called chronaxia .