Electroencephalographic technique from an engineer's point of view

A fairly recent medical usage of electronic equipment is in the recording of the electrical activity of the brain. High-gain, high-fidelity amplifying equipment is used to record 50-microvolt, 2- to 40-cycle-per-second impulses from the brain. A brief summary of interpretation is made, particularly in reference to artifact. A new type of electrode is described which fulfills the criteria for good leads. Suggestions on the improvement of existing equipment are made, such as to improve calibration accuracy and recorder performance.