title: Interleaved, multisite electrical stimulation of cat sciatic nerve produces fatigue-resistant, ripple-free motor responses.
abstract: We studied the use of physiologically based, multisite, intrafascicular electrical stimulation of the sciatic nerve to achieve ripple-free contractions and sustained, fatigue-resistant forces over a physiological range of forces in cat gastrocnemius muscle. Electrode arrays containing 100, 0.5-1.5-mm-long penetrating microelectrodes were inserted into the sciatic nerves of cats, and forces generated by gastrocnemius muscles in response to stimulation of the nerves were monitored via a force transducer attached to the tendons. In single-electrode stimulation, responses evoked by low-frequency [15 pulses/second, (p/s)] stimulation exhibited greater fatigue resistance than did responses evoked by higher frequency stimulation (30 and 60 p/s), but showed far more ripple within each response. We compared interleaved 15 p/s stimulation of four electrodes (100 micros biphasic pulses, 750-ms pulse trains) that produced a net stimulation frequency of 60 p/s with multielectrode 60 p/s quasi-simultaneous stimulation protocols. Across a broad range of forces (10% to 80% of maximum), responses evoked by multielectrode 15 p/s interleaved stimulation exhibited substantially less fatigue than did responses evoked by 60 p/s quasi-simultaneous stimulation, and less ripple than responses evoked by single-electrode 15 p/s stimulation. The effectiveness of this physiologically based stimulation paradigm encourages its application in the field of motor neuroprosthetics.
authors.affiliation: Department of Bioengineering, University of Utah, Salt Lake City, UT 84112, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: McDonnall
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Clark
authors.forename: Richard A
authors.initials: RA
authors.lastname: Normann
mesh_terms: D000818:Animals; D002415:Cats; D004558:Electric Stimulation / Q000295:instrumentation* / Q000379:methods; D004567:Electrodes, Implanted; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008839:Microelectrodes; D009119:Muscle Contraction / Q000502:physiology*; D018763:Muscle Fatigue / Q000502:physiology; D018482:Muscle, Skeletal / Q000294:innervation* / Q000502:physiology*; D012584:Sciatic Nerve / Q000502:physiology*; D013314:Stress, Mechanical