title: Designing a thalamic somatosensory neural prosthesis: consistency and persistence of percepts evoked by electrical stimulation.
abstract: Intuitive somatosensory feedback is required for fine motor control. Here we explored whether thalamic electrical stimulation could provide the necessary durations and consistency of percepts for a human somatosensory neural prosthetic. Continuous and cycling high-frequency (185 Hz, 0.21 ms pulse duration charge balanced square wave) electrical pulses with the cycling patterns varying between 7% and 67% of duty cycle were applied in five patients with chronically implanted deep brain stimulators. Stimulation produced similar percepts to those elicited immediately after surgery. While consecutive continuous stimuli produced decreasing durations of sensation, the amplitude and type of percept did not change. Cycling stimulation with shorter duty cycles produced more persisting percepts. These features suggest that the thalamus could provide a site for stable and enduring sensations necessary for a long term somatosensory neural prosthesis.
authors.affiliation: Department of Clinical Neurosciences, University of Calgary, Calgary, T2N 4N1 AB, Canada.
authors.forename: Ethan A
authors.initials: EA
authors.lastname: Heming
authors.forename: Ryan
authors.initials: R
authors.lastname: Choo
authors.forename: Jonathan N
authors.initials: JN
authors.lastname: Davies
authors.forename: Zelma H T
authors.initials: ZH
authors.lastname: Kiss
mesh_terms: D000328:Adult; D046690:Deep Brain Stimulation; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D005260:Female; D006801:Humans; D008297:Male; D058117:Neural Prostheses; D011474:Prosthesis Design / Q000379:methods*; D011601:Psychophysics; D015203:Reproducibility of Results; D012677:Sensation / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology*; D013788:Thalamus / Q000502:physiology*