An EIT electrode protocol for obtaining optimal current density in the primary visual cortex

摘要: We are developing a new imaging modality, which may be capable of small impedance changes in the human head due to neuronal depolarization. As skull is irregular shape and less conductive, key issue at present know current density distribution specific regions brain through electrodes can injected for optimum results. have developed realistic Finite Element Method (FEM) head, includes our region interest, primary visual cortex (V1) simulated physiological change variation conductivity V1 when neurons firing during evoked response. A near DC 100 μA was driven possible pairs 31 using EIT techniques. The resulting surface potentials were calculated whole remained unperturbed, or changed by 1%. greatest mean 0.020 ± 0.005 μAmm, occurred with injection two positioned occipital cortex. corresponding maximum potential from baseline about 0.02%. Saline tank experiments confirmed accuracy estimated standing potentials. This has permitted us estimate electrode positions most likely permit recording suggests that changes, although tiny, just discernible noise.