Patent ID: 8571667
Filing Date: 2013-10-29
Classification: A61N

Abstract:
1. A neurostimulation medical system, comprising: a controller circuit configured to generate control signals in response to external programming signals; a stimulation circuit configured to generate stimulation signals in response to the control signals; a plurality of implantable electrodes; a plurality of conductors configured to deliver the stimulation signals from the stimulation circuit to the electrodes; and an enclosure that houses the controller circuit and the stimulation circuit therein, the enclosure containing an area that is electrically conductive, wherein the controller circuit and the stimulation circuit are configured to ramp up a current at the enclosure during an initial calibration stage and determine therefrom a first current level corresponding to a perception threshold at the enclosure and a second current level corresponding to a pain threshold at the enclosure; wherein the stimulation circuit is configured to activate a first subset of the electrodes to a first polarity, a second subset of the electrodes to a second polarity, and the enclosure to one of the first and second polarities, so as to cause a first stimulation path to be formed between at least one of the electrodes in the first subset and at least one of the electrodes in the second subset, and a second stimulation path to be formed between the enclosure and at least one of the electrodes in the first and second subsets, and wherein the activated enclosure is programmed by the controller circuit to actively sink or source an amount of electrical current that is capped at one of: the first current level corresponding to the perception threshold, and the second current level corresponding to the pain threshold.