Electroencephalograph having meter probe movable in a calvarium-shaped liquid filled tank and method of use

Claim 1

An electroencephalograph apparatus, comprising a hollow calvarium-shaped member of an electrical insulating material, a plurality of fixed electrodes distributed over and attached to said member, each fixed electrode having an end portion exposed to the hollow interior in said member, a plurality of movable electrodes providing a movable electrode for each said fixed electrode, negative feedback and voltage signal averaging means connected to said fixed electrodes, voltage signal amplifying means electrically connecting each movable electrode to the corresponding fixed electrode therefor and connected to said voltage signal averaging means, such that differences only in signals applied to each movable electrode relative to the average of the voltage signals applied to all the movable electrodes will be amplified to a detectable magnitude and applied to the corresponding fixed electrode, an electrically conducting liquid in said member and covering said exposed end portions of said electrodes, a sensing probe movable within said hollow interior, for detecting voltage differences in said electrically conducting liquid in said member, said voltage differences being produced therein by said fixed electrodes, and means for indicating said voltage differences detected by said probe, whereby each said movable electrode may be electrically connected to the corresponding position on the scalp of a living body to the position of the corresponding fixed electrode thereto on said member, said probe may be moved within said liquid to detect a substantially equivalent voltage field therein to that of a brain within said scalp, and differences in said field may be indicated by said means for indicating said voltage differences.

Claim 5

A method of obtaining electroencephalograh readings, comprising providing a hollow calvarium-shaped member filled with an electrically conducting liquid and with electrodes fixed at several spaced locations, applying movable electrodes to the scalp of a living body, at positions corresponding to the fixed electrodes, to obtain voltage signals therefrom, obtaining the average voltage of all of said voltage signals, comparing each said voltage signal with the average, amplifying differences only in said voltage signals to said average, applying said amplified differences to the corresponding one of said fixed electrodes, inserting a probe in said liquid in said member, detecting voltage differences in said liquid, and measuring said voltage differences.

Claim 6

A method of obtaining electroencephalograh readings, comprising providing a hollow calvarium-shaped member filled with an electrically conducting liquid and with electrodes fixed at several spaced locations, applying movable electrodes to the scalp of a living body, at positions corresponding to the fixed electrodes, to obtain voltage signals therefrom, obtaining the average voltage of all of said voltage signals, comparing each said voltage signal with the average, amplifying differences only in said voltage signals to said average, applying said amplified differences to the corresponding one of said fixed electrodes, inserting a probe in said liquid in said member, detecting voltage differences in said liquid, and measuring said voltage differences.