Electrical stimulus artifact cancellation and neural spike detection on large multi-electrode arrays
Fig 7
Filtering (Eq 10) leads to a better, less spike-corrupted artifact estimate in our simulations.
A effect of filtering on traces for two non-stimulating electrodes, at a fixed amplitude of stimulation (2.2μA). A1,A3 raw traces, A2,A4 filtered traces. Notice the two main features of the filter: first, it principally affects traces containing spikes, a consequence of the localized nature of the kernel in Eq 2. Second, it helps eliminate high-frequency noise. B through simulations, we showed that filtering leads to improved results in challenging situations. Two filters—only smoothing and localization + smoothing—were compared to the omission of filtering. In all cases, to rule out that performance changes were due to the extrapolation estimator, extrapolation was done with the naive estimator. B1 results in a less challenging situation. B2 results in the heavily subsampled (nj = 1) case. B3 results in the high-noise variance (σ2 = 10) case.