A Continuous Multichannel Automatic Curve Reader

Details of construction and characteristics of performance for a multichannel analog curve reader are described. This system is intended primarily for automatic transcription of bioelectric-data recordings such as electroencephalograms, and employs the principle of phase-modulated analog sampling. It utilizes electro-encephalographs, polygraphs, or similar devices through which the original recordings are rerun for transcription; the usual ink-writing pens of these devices are replaced by self-contained photoelectric scanning pens. The system is versatile in its operation, permitting either the slow-speed exact duplication of ink-written traces or similar data, or high-speed transcriptions (within the limits of the sampling theorem) for computer analysis, either directly, or via the intermediary of magnetic-tape recordings. The number of channels is optional and readily expandable; an 8-channel system has been constructed.