title: Influence of system integration and packaging on its inductive power link for an integrated wireless neural interface.
abstract: In an integrated wireless neural interface based on the Utah electrode array, the implanted electronics are supplied with power through inductive coupling between two coils. This inductive link is affected by conductive and dielectric materials and media surrounding the implant coil. In this study, the influences of the integration of an implant coil on a silicon-based IC and electrode array, thin-film Parylene-C encapsulation, and physiological medium surrounding the coil were investigated systematically and quantitatively by empirical measurements. A few embodiments of implant coils with different geometrical parameters were made with a diameter of approximately 5.5 mm by winding fine wire with a diameter of approximately 50 mum. The parasitic influences affecting the inductive link were empirically investigated by measuring the electrical properties of coils in different configurations and in different media. The distance of power transmission between the transmit and receive coils was measured when the receive coil was in air and immersed in phosphate buffered saline solution to simulate an implanted physiological environment. The results from this study quantitatively address the influences of factors such as device integration, encapsulation, and implantation on its inductive power link, and suggest how to maximize the efficiency in power transmission for such neural interface devices powered inductively.
authors.affiliation: Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT 84112, USA. soheekim@gist.ac.kr
authors.forename: Sohee
authors.initials: S
authors.lastname: Kim
authors.forename: Reid R
authors.initials: RR
authors.lastname: Harrison
authors.forename: Florian
authors.initials: F
authors.lastname: Solzbacher
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D017076:Computer-Aided Design; D011211:Electric Power Supplies; D004567:Electrodes, Implanted; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D010525:Peripheral Nerves / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018511:Systems Integration; D013686:Telemetry / Q000295:instrumentation* / Q000379:methods