System and method to automatically maintain electrical stimulation intensity

A method, comprising:

• delivering electrical current to at least one electrode that is in contact with tissue of a patient to provide an effect, wherein:
• the delivered electrical current is representable using a current-time curve;
• and
• adjustable stimulation parameters are used to define the delivered electrical current including an area under the current-time curve that reflects a total charge transfer over a time period which causes the effect of the delivered electrical current;
• adjusting at least a first one of the stimulation parameters, and automatically adjusting at least a second of the stimulation parameters in response to adjusting the least the first of the stimulation parameters, wherein the least the second of the stimulation parameters is automatically adjusted to maintain the total charge transfer by maintaining the area under the current-time curve over the time period.

A method, comprising:

• applying an electrical stimulus to at least one electrode that is in contact with tissue of a patient to provide an effect, the applied electrical stimulus comprising a plurality of pulses defined by a pulse width value and an amplitude value;
• adjusting one of the amplitude value or the pulse width value;
• automatically adjusting the other of the amplitude value and the pulse width value in response to the adjustment of the one of the amplitude value or the pulse width value, wherein the automatically adjusting is based on a calculation that includes a chronaxie value;
• determining that the effect of the electrical stimulus changes as a result of the automatic adjustment;
• and
• adjusting the chronaxie value.