title: A miniaturized system for spike-triggered intracortical microstimulation in an ambulatory rat.
abstract: This paper reports on a miniaturized system for spike-triggered intracortical microstimulation (ICMS) in an ambulatory rat. The head-mounted microdevice comprises a previously developed application-specific integrated circuit fabricated in 0.35-μm two-poly four-metal complementary metal-oxide-semiconductor technology, which is assembled and packaged on a miniature rigid-flex substrate together with a few external components for programming, supply regulation, and wireless operation. The microdevice operates autonomously from a single 1.55-V battery, measures 3.6  cm × 1.3  cm × 0.6  cm, weighs 1.7  g (including the battery), and is capable of stimulating as well as recording the neural response to ICMS in biological experiments with anesthetized laboratory rats. Moreover, it has been interfaced with silicon microelectrodes chronically implanted in the cerebral cortex of an ambulatory rat and successfully delivers electrical stimuli to the second somatosensory area when triggered by neural activity from the rostral forelimb area with a user-adjustable spike-stimulus time delay. The spike-triggered ICMS is further shown to modulate the neuronal firing rate, indicating that it is physiologically effective.
authors.affiliation: Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, OH 44106, USA. mxa208@cwru.edu
authors.forename: Meysam
authors.initials: M
authors.lastname: Azin
authors.forename: David J
authors.initials: DJ
authors.lastname: Guggenmos
authors.forename: Scott
authors.initials: S
authors.lastname: Barbay
authors.forename: Randolph J
authors.initials: RJ
authors.lastname: Nudo
authors.forename: Pedram
authors.initials: P
authors.lastname: Mohseni
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology* / Q000601:surgery; D004558:Electric Stimulation / Q000295:instrumentation* / Q000379:methods; D004567:Electrodes, Implanted; D006257:Head / Q000601:surgery; D008839:Microelectrodes; D055616:Microtechnology / Q000295:instrumentation*; D058117:Neural Prostheses; D051381:Rats; D020318:Rats, Long-Evans; D016138:Walking; D059015:Wireless Technology