Walter D Freeman

US Patent:

47532467, Jun 28, 1988

Filed:

Mar 28, 1986

Appl. No.:

6/845564

Inventors:

Walter J. Freeman - Berkeley CA

Assignee:

The Regents of the University of California

International Classification:

A61B 504

US Classification:

128731

Abstract:

Method and apparatus for producing enhanced EEG or MEG information related to a selected brain activity in a subject. The apparatus includes a two-dimensional array of at least about 16 sensors for recording EEG or MEG traces from the subject. Control and test traces recorded before and during an interval in which the brain activity is occurring, respectively, are each decomposed into a series of basis functions which may be analytic components such as temporal frequency components, generated by spectral decomposition of an ensemble average of the recorded traces, or principal components determined by principal component analysis. The control and test traces are then represented as a sum of the products of the individual basis functions times a spatial domain matrix which represents the spatial pattern of amplitudes of that basis function, as measured by the individual sensors in the array. The signals can be extracted by filtering spatially and/or temporally to remove basis function components which are not related to the selected brain activity (clutter), and to remove spatial frequencies inherent in the spatial domain matrices to optimize the contrast between control and and corresponding test matrices, for each selected basis function.

US Patent:

47486740, May 31, 1988

Filed:

Oct 7, 1986

Appl. No.:

6/916187

Inventors:

Walter J. Freeman - Berkeley CA

Assignee:

The Regents of the University of Calif. - Berkeley CA

International Classification:

G06K 962

US Classification:

382 14

Abstract:

A pattern learning and recognition device. The device includes a parallel processing network for receiving and processing an N-dimensional vector input, and a control system for calculating, and storing output signal correlation information during the learning mode of the device, and for distributing the learned information to the network, in the form of feedback gain, during the pattern-recognition mode of the device. The network is preferably composed of an array of N oscillatory units designed to bifurcate from a rest to an active state when stimulated with a threshold input voltage surge.

US Patent:

44162880, Nov 22, 1983

Filed:

Aug 14, 1980

Appl. No.:

6/178170

Inventors:

Walter J. Freeman - Berkeley CA

Assignee:

The Regents of the University of California - Berkeley CA

International Classification:

A61B 504

US Classification:

128731

Abstract:

Signals representative of electric potentials generated by cells of a given depth in the cerebral cortex or in other organs of a living body are detected at the surface thereof by an array of electrodes. These signals are amplified, digitized, and then spatially deconvoluted, to remove distortions introduced by the physical properties of the organ, to recover the desired pattern of electric potential within the living body.