1. A system comprising: a plurality of electrodes to measure electrical signals corresponding to input channel data from a patient, each of the plurality of electrodes corresponding to a node that defines a respective input channel; and a processor to access memory comprising instructions executable by the processor, the instructions comprising: a first spatial similarity measurement function to compute a measure of similarity between the input channel data for each node and a set of neighboring nodes to identify a spatial correlated set of channels having an integrity that is considered one of bad or good; an amplitude analyzer programmed to determine a subset of channels meeting amplitude criteria; a second spatial similarity measurement function to compute, for each channel in the subset of channels meeting the amplitude criteria, a measure of similarity between the input channel data for each node and a set of neighboring nodes to identify an amplitude correlated set of channels having an integrity that is considered one of bad or good; and a combiner programmed to generate output data representing the integrity of the plurality of input channels based on the spatial correlated set of channels and the amplitude correlated set of channels; and a display device to provide a graphical representation of the output data that includes an indication of the integrity of the plurality of input channels, wherein the one or more channels with low integrity are selectively included or excluded from further processing according to a user input.