Towards a Switched-Capacitor Based Stimulator for Efficient Deep-Brain Stimulation Jose Vidal Jr. [Student Member, IEEE] and Electrical and Computer Engineering Department, Georgia Institute of Technology, Atlanta, GA 30308 USA (phone: 256-627-1123) Maysam Ghovanloo [Senior Member, IEEE] Electrical and Computer Engineering Department, Georgia Institute of Technology, Atlanta, GA 30308 USA Jose Vidal: jose.vidal@gatech.edu; Maysam Ghovanloo: mgh@gatech.edu Abstract We have developed a novel 4-channel prototype stimulation circuit for implantable neurological stimulators (INS). This Switched-Capacitor based Stimulator (SCS) aims to utilize charge storage and charge injection techniques to take advantage of both the efficiency of conventional voltage- controlled stimulators (VCS) and the safety and controllability of current-controlled stimulators (CCS). The discrete SCS prototype offers fine control over stimulation parameters such as voltage, current, pulse width, frequency, and active electrode channel via a LabVIEW graphical user interface (GUI) when connected to a PC through USB. Furthermore, the prototype utilizes a floating current sensor to provide charge-balanced biphasic stimulation and ensure safety. The stimulator was analyzed using an electrode-electrolyte interface (EEI) model as well as with a pair of pacing electrodes in saline. The primary motivation of this research is to test the feasibility and functionality of a safe, effective, and power-efficient switched-capacitor based stimulator for use in Deep Brain Stimulation. I. Introduction Integrated medical stimulators have been around for almost six decades, beginning with the development of the implantable cardiac pacemaker and gaining momentum with the miniaturization of integrated circuit technologies [1]. Year by year, devices are becoming smaller, more accurate, and more capable while consuming less power. Such advances in technology have allowed engineers and physicians to push the state of art and utilize implantable neurostimulators to treat deafness, pain, blindness, Parkinson’s and numerous other illnesses [2]. To ensure wide acceptance of these new treatments, it is essential that these devices be designed to be minimally invasive, safe, and extensively autonomous. As a result, wireless power and efficient stimulation techniques have been popular topics of research [3]. As the field of medical devices has grown, many new techniques and therapies using electrical stimulation have come to the forefront of research. Namely, Deep Brain Stimulation (DBS), which has recently been proven as an effective therapy for treating Parkinson’s disease, Essential Tremor and Dystonia, is a therapy in need of miniaturization and sophisticated stimulation techniques [4]. Current DBS implants consist of a battery powered device, implanted under the skin in the chest area, with four leads that run across the neck to reach electrodes that are implanted in the inner regions of the brain from the top of the head. By eliminating the implanted battery and reducing the number of components, NIH Public Access Author Manuscript Conf Proc IEEE Eng Med Biol Soc. Author manuscript; available in PMC 2013 February 25. Published in final edited form as: Conf Proc IEEE Eng Med Biol Soc. 2010 ; 2010: 2927–2930. doi:10.1109/IEMBS.2010.5626290. NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript