DocumentCode :
1338866
Title :
Asymmetric Versus Symmetric Pulses for Cortical Microstimulation
Author :
Koivuniemi, Andrew S. ; Otto, Kevin J.
Author_Institution :
Weldon Sch. of Biomed. Eng., Purdue Univ., West Lafayette, IN, USA
Volume :
19
Issue :
5
fYear :
2011
Firstpage :
468
Lastpage :
476
Abstract :
Intracortical microstimulation (ICMS), which has shown promise in the visual, auditory and somatosensory systems as a platform for sensory prostheses, typically relies on charged balanced, symmetric, biphasic stimulation. However, neural stimulation models as well as experiments conducted in cochlear implant users have suggested that charge balanced asymmetric pulses could generate lower detection thresholds for stimulation in terms of charge per phase. For this study, rats were chronically implanted with microelectrode arrays unilaterally in their right auditory cortex and then trained to detect ICMS delivered through a single electrode site in order to determine their behavioral threshold. This model was used in two experiments. The first experiment addressed the effect of lead phase direction, asymmetry, and phase duration on detection threshold. The second experiment fixed the cathode phase duration at 123 μs and varied only the phase asymmetry and lead phase direction. Taken together, the results of these experiments suggest that, for ICMS, the primary determinant of threshold level is cathode phase duration, and that asymmetry provides no significant advantage when compared to symmetric, cathode leading pulses. However, symmetric anode leading pulses of less than or equal to 205 μs per phase consistently showed higher thresholds when compared to all other pulses of equal cathode phase duration.
Keywords :
bioMEMS; bioelectric phenomena; biomedical electrodes; cochlear implants; microelectrodes; neurophysiology; ICMS detection; asymmetric pulses; asymmetry effects; auditory system; biphasic stimulation; cathode phase duration; charged balanced stimulation; chronically implanted microelectrode arrays; cochlear implant users; detection threshold; intracortical microstimulation; lead phase direction effects; neural stimulation models; phase duration effects; right auditory cortex; sensory prosthesis platform; somatosensory system; symmetric anode leading pulse; symmetric pulses; symmetric stimulation; time 123 mus; visual system; Anodes; Cathodes; Implants; Rats; Surgery; Animal behavior; detection threshold; interface engineering; neuroprostheses; waveforms; Acoustic Stimulation; Algorithms; Animals; Auditory Cortex; Behavior, Animal; Electric Stimulation; Electrodes; Electrodes, Implanted; Functional Laterality; Male; Microelectrodes; Psychomotor Performance; Rats; Rats, Sprague-Dawley; User-Computer Interface;
fLanguage :
English
Journal_Title :
Neural Systems and Rehabilitation Engineering, IEEE Transactions on
Publisher :
ieee
ISSN :
1534-4320
Type :
jour
DOI :
10.1109/TNSRE.2011.2166563
Filename :
6033047
Link To Document :
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