Devices and Methods to Provide Stimulation Therapy in the Presence of External Conditions that Induce Undesirable Perturbations

摘要

Devices and methods compensate for perturbations in a stimulation signal caused by external conditions such as a magnetic field of an MRI machine so that stimulation therapy may continue in the presence of the external condition. Compensation for the perturbations during a stimulation pulse of a stimulation phase may be provided by using feedback within a stimulation current source. Perturbations during a recharge phase may be addressed by utilizing an active recharge at least when the external condition is present. Furthermore, compensation for perturbations during a recharge pulse of the active recharge phase may be provided by using feedback within a recharge current source. Passive recharge may be used instead of active recharge when the external condition is not present to preserve battery life of the stimulation device. The stimulation device may include a sensor to detect the external condition so that an appropriate mode of recharge may be chosen.

主权项

1. A method of providing stimulation to a body, comprising:
setting a first reference voltage; generating a stimulation current in a first direction through a first output transistor, a coupling capacitor, and a first electrode during a stimulation phase; utilizing a difference between the first reference voltage and a voltage proportional to the stimulation current to control the stimulation current through the first output transistor during the stimulation phase; and generating a recharge current in a second direction through a second output transistor, the recharge current passing through the coupling capacitor and the first electrode in a direction opposite the first direction during a recharge phase occurring at a time other than during the stimulation phase.