Electron transfer processes occurring on platinum neural stimulating electrodes: pulsing experiments for cathodic-first, charge-balanced, biphasic pulses for 0.566 ⩽ k ⩽ 2.3 in rat subcutaneous tissues
| Autor: | Eric M Hudak, Doe Kumsa, Narendra Bhadra, J. Thomas Mortimer |
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| Rok vydání: | 2017 |
| Předmět: |
020209 energy
Inorganic chemistry Biomedical Engineering chemistry.chemical_element 02 engineering and technology Electrochemistry Rats Sprague-Dawley 03 medical and health sciences Cellular and Molecular Neuroscience Electron transfer 0302 clinical medicine Subcutaneous Tissue Phase (matter) 0202 electrical engineering electronic engineering information engineering Animals Dissolution Electrodes Platinum Neurons Chemistry Electric Stimulation Anode Electrodes Implanted Rats Electrode 030217 neurology & neurosurgery Electrode potential |
| Zdroj: | Journal of neural engineering. 14(5) |
| ISSN: | 1741-2552 |
| Popis: | OBJECTIVE Charge injection through platinum neural stimulation electrodes is often constrained by the Shannon limit (Shannon 1992 IEEE Trans. Biomed. Eng. 39 424-6) of k = 1.75. By leveraging the tools of electrochemistry to better understand the reactions at electrode-tissue interface, we endeavor to find a way to safely inject more charge than allowed if the traditional Shannon limit were followed. APPROACH In previous studies on platinum electrodes using charge-balanced, cathodic-first, biphasic pulses, we noted that during the secondary anodic phase, the electrode potential moves into a range where platinum dissolution is possible when charge injection is greater than k = 1.75. Platinum dissolution products are known to be toxic to brain tissues. We hypothesize that by injecting less charge in the anodic phase than the cathodic phase, the anodic potential excursions will decrease, thereby avoiding potentials where platinum dissolution is more likely. MAIN RESULTS Our findings show that using these charge-imbalanced pulses decreases the anodic potential excursions to a level where platinum oxidation and dissolution are less likely, and aligns the anodic potentials with those observed with charge-balanced stimulation at k |
| Databáze: | OpenAIRE |
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