IEEE transactions on bio-medical engineering
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IEEE Trans Biomed Eng · Oct 1990
Charge density and charge per phase as cofactors in neural injury induced by electrical stimulation.
The possibility of neural injury during prolonged electrical stimulation of the brain imposes some constraints on the use of this technique for therapeutic and experimental applications. Stimulating electrodes of various sizes were used to investigate the interactions of two stimulus parameters, charge density and charge per phase, in determining the threshold of neural injury induced by electrical stimulation. Platinum electrodes ranging in size from 0.002 to 0.5 cm2 were implanted over the parietal cortex of adult cats. ⋯ The results show that charge density (as measured at the surface of the stimulating electrode), and charge per phase, interact in a synergistic manner to determine the threshold of stimulation-induced neural injury. This interaction occurs over a wide range of both parameters; for charge density from at least 10 to 800 microC/cm2 and, for charge per phase, from at least 0.05 to 5.0 microC per phase. The significance of these findings in elucidating the mechanisms underlying stimulation-induced injury is discussed.