ELIMINATING ACQUISITION-RELATED ARTIFACTS IN ELECTROPHYSIOLOGICAL RECORDING

An alternating recording electrode to eliminate acquisition related artifacts in electro-physiological recording. In order to eliminate artifacts in neural response recordings, a pair of recordings is made with, respectively, inverted and non-inverted polarity at one pair of electrodes. One component of the recording artifact is introduced by the electronics of the acquisition system itself. This is mainly the switch on or acquisitional artifact. Rather than eliminate this by subtracting the result of a recording without stimulus from the actual recording, two recordings based on an alternation of the polarities of the active and reference electrode are used. This alternates the polarity of the external signal but not the internal electrical artifact. Hence the average of the two recordings will eliminate the acquisition artifact without the need for an extra recording of, say, a baseline. A principal benefit of the technology described herein is a marked improvement in overall recording speed because the total number of measurements that need to be made is reduced. Furthermore, since each measurement increases the levels of noise, a reduction in the number of measurements has a beneficial effect on the overall signal-to-noise ratio.