title: Electrical performance of penetrating microelectrodes chronically implanted in cat cortex.
abstract: Penetrating multielectrode arrays with electrode coatings of sputtered iridium oxide (SIROF) have been implanted chronically in cat cortex for periods over 300 days. The ability of these electrodes to inject charge at levels above expected thresholds for neural excitation has been examined in vivo by measurements of voltage transients in response to current-controlled, cathodal stimulation pulsing. The effect of current pulse width from 150 μs to 500 μs and voltage biasing of the electrodes in the interpulse period at two levels, 0.0 V and 0.6 V vs. Ag|AgCl, were also investigated. The results of in vivo characterization of the electrodes by open-circuit potential measurements, cyclic voltammetry and impedance spectroscopy are also reported.
authors.affiliation: EIC Laboratories, Inc Norwood, MA 02062, USA. skane@eiclabs.com
authors.forename: Sheryl R
authors.initials: SR
authors.lastname: Kane
authors.forename: Stuart F
authors.initials: SF
authors.lastname: Cogan
authors.forename: Julia
authors.initials: J
authors.lastname: Ehrlich
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Plante
authors.forename: Douglas B
authors.initials: DB
authors.lastname: McCreery
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D002415:Cats; D017097:Electric Impedance; D004558:Electric Stimulation / Q000295:instrumentation*; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007495:Iridium / Q000737:chemistry*; D008839:Microelectrodes; D009044:Motor Cortex / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology*
chemical_list: D001672:Biocompatible Materials; D007495:Iridium