Patent ID: 6909917

Claim:
An implantable pulse generator for use with an array of electrodes implantable within a patient so as to lie adjacent selected nerve tissue, the implantable pulse generator being characterized by having current-steering capability, the implantable pulse generator comprising: a pulse generator responsive to programming signals for generating stimulation currents; means responsive to the programming signals for selectively applying the stimulation currents to at least two electrodes within the array of electrodes, said at least two electrodes comprising a first group of electrodes; and current steering means responsive to directional signals for steering the stimulation currents from the first group of electrodes to a second group of electrodes; wherein stimulation currents flowing between electrodes within the first group of electrodes are steered to electrodes within the second group of electrodes as controlled by the directional signals; wherein the current steering means includes means for redistributing the stimulation currents from the electrodes within the first group of electrodes to the electrodes within the second group of electrodes in a manner that is perceived as a smooth redistribution; and wherein the redistributing means includes a formula-based algorithm means for redistributing stimulation current from one of the electrodes included within the array of electrodes to another of the electrodes included within the array of electrodes.