Neurostimulation method and system for active emulation of passive discharge in presence of mri/emi interference

Abstract

A neurostimulation (NS) system and method are provided. The NS system includes an array of electrodes positioned within a patient. The array of electrodes includes an active electrode. The active electrode is configured to be a cathode electrode located proximate to neural tissue of interest that is associated with a target region. The NS system includes an anode electrode and an electromagnetic interference (EMI) antenna. A control circuit is configured to control delivery of a NS therapy during a therapy delivery interval. The NS therapy is to be delivered between the anode electrode and the active electrode. The NS system develops a residual voltage between the anode electrode and the active electrode over the therapy delivery interval. A current regulator (CR) circuit is connected to the cathode electrode. The CR circuit is configured to control current flow through the cathode electrodes. During a discharge operation, the control circuit is configured to manage the CR circuit to control a discharge current flow over the discharge operation to discharge the residual voltage after therapy delivery in a manner that follows an actively emulated passive discharge (AEPD) profile. During the discharge operation, the CR circuit is connected to the inactive electrode. The CR circuit receives, as a first input, an EMI feedback signal from the EMI antenna. The CR circuit is configured to regulate the discharge current flow through the active electrode based on the EMI feedback signal, to maintain the AEPD profile over the discharge operation while in a presence of an EMI event.