Multipolar Stimulator for DBS Application with Concurrent Imbalance Compensation.

Deep brain stimulation systems which consist of recording, stimulation, and detection functions play a key role in the treatment of neurological disorders such as Parkinson’s, Epilepsy, etc. In this paper, a multipolar biphasic current stimulation system is presented. The system includes 5 stimulators on each side of the brain, four of which are connected locally in the brain, and the fifth is connected to the body of the implantable pulse generator for monopolar stimulation. This stimulator can also be used as a voltage stimulator. The maximum current that can be supplied by the stimulator is 12.75 mA, with 8-bit resolution. Passive charge balancing is used, and due to safety concerns, a DC blocking capacitor is used for electrical isolation and negligible DC current flow even at system failure. In the proposed architecture, the mismatch among the total stimulation current sinks can be compensated up to ±45% by current sources, and the current errors are distributed with the ideal ratio of the adjusted currents. The stimulator voltage can be varied up to 30V. The efficiency of this stimulator at the mid-high load is 55% without considering the digital control core.