Abstract: A dry electrode, which is a single-plate capacitor, is particularly adapted to be placed on a patient's scalp to detect brain waves in an EEG system. The electrode comprises a metal disk sandwiched between very thin and relatively thicker layers of ceramic. The metal disk is attached to a small disk printed circuit board that carries an amplifier to amplify the brain waves detected by the electrode. The quality of contact of the electrode with the patient is measured by applying a pulse or voltage step through the ground electrode.

Abstract: An efficient, objective testing method and system for evaluating mental acuity and changes in mental acuity is described. The method and system are based on measuring an individual's behavioral responses and brain function during a brief test of working memory and passive control condition. The method and system is designed to assess an individual's overall cognitive ability (“general intelligence”), and whether that overall cognitive ability has been significantly affected by a variety of factors such as progressive disease processes, medication, stress, fatigue or training. The method and system can be used to determine whether drugs being evaluated to treat diseases or conditions affecting higher cognitive brain function have a significant positive effect on delaying or improving the symptoms of such a disease or condition, especially during clinical trials for drug approval and subsequent marketing.

Abstract: A method which is accurate and yet relatively simple, rapid and inexpensive for estimating 3-D coordinates of EEG (electroencephalograph) electrode positions on the head. The electrode positions of any number of scalp electrodes placed according to the standard 10/10 electrode position system are computed by a computer system based on 14 manually measured inter-electrode distances and 9 electrode-to-skull landmark straight-line distances. The measurements are made manually using digital calipers.

Abstract: The spatial resolution of electroencephalograph (EEG) medical images is improved using "Deblurring" based on a digital computer based analysis using volumetric finite elements and a biophysical model of the passive electrical conductivity of a subject's head.

Abstract: In an EEG (electroencephalogram) system to detect brain waves from a subject, the adverse effect on the EEG recording of artifact due to head, body and eye movements is reduced. A head and body movement reference signal can be provided by an accelerometer, motion detector or, alternatively, spatial average of EEG channels. Eye motion sensors are used as a reference for eye movement artifacts. A composite reference signal consists of the head, body and eye movement reference signals. The contaminated EEG is the primary input to the adaptive movement and eye artifact canceler, in which an adaptive filter estimates the contaminants in the measured EEG data, and then subtracts them from the primary signal to obtain the corrected EEG data.

Abstract: A human-computer interface uses neuroelectric signals recorded from the user's scalp i.e. electroencephalograms (EEGs) to alter the program being run by the computer, for example to present less or more difficult material to the user, depending on the user's neurocognitive on-line workload score. Each user is tested with a standard battery of tasks, while wearing an EEG hat, to calibrate a neurocognitive workload function. The calibrated function is user-specific and is obtained by modifying a neural network pattern analyzer which has been previously trained to index neurocognitive workload using data from a group of subjects performing the same battery of tasks.

Abstract: An injector system to inject a bolus of electrolyte into EEG electrodes includes a pressure pump containing electrolyte and a pen-like injector which is filled from the pump for the injection of a bolus for each EEG electrode. The injector includes a finger-operated plunger having a piston, an electrolyte chamber, a hollow shaft portion of the plunger, and a flexible bottom portion having flaps which are spread open by the injector head (end of the plunger).

Abstract: In an electroencephalographic (EEG) system and method the subject's brain waves are recorded using electrodes removably connected to the scalp. The spatial resolution may be improved, in one embodiment, by "Deblurring", based on digital computer processing measurements of the positions of the electrodes; measurements of the subject's head size, shape, scalp thickness, skull thickness and brain shape; and estimates of the conductivity of the skull, scalp and cerebral spinal fluid.

Abstract: A testing method and system for testing the mental performance capability of a human subject includes a digital computer workstation which presents a test to the subject, such as visumotor memory task. Simultaneously, a physiological sensing and amplification device amplifies and analyzes the subject's brain waves, eye activity, scalp and facial muscle activity, heart activity, respiration and/or skin conductance. The subject's test scores and physiological activity are compared, by the workstation, with previously collected normative measurements for that subject to determine if the test was passed with a passing score and, if so, whether the subject, in order to pass the test, exceeded a standard based upon the subject's normal mental effort in taking the same or similar tests.

Abstract: A computer system utilizes a parallel data broadcast architecture, called "PDB" is adapted to be connected to a host computer system. In one digital embodiment, the PDB system includes an interface and global memory which is connected to the host computer system and to three common buses. The buses, in parallel, are, respectively, a data broadcast bus, an instruction bus and an output bus, each bus being connected to a plurality of computational units. Each computational unit includes an arithmetic processor, which preferably, in this embodiment, is a digital signal processor (a special-purpose integrated circuit microprocessor), a local memory and a local program memory. The computational units receive the input data simultaneously and in parallel; transform the data, depending on the parameters received from the instruction bus; and communicate their results, by multiplexing, to the output bus.

Abstract: An improved brain wave electroencephalograph (EEG) method measures the physical positions of EEG electrodes applied to the subject's scalp. A set of standard cross-directional lines are obtained to provide measurements of the subject's head and a computer system automatically defines the subject's head shape according to predetermined head shape classes. The position of the electrode on the subject's scalp is then determined by scaling the measurements of the subject's head to a head model of the same head shape class.

Abstract: In a brain wave detecting system, in one embodiment, a flexible hat is placed on the head of the patient. The hat contains a plurality of electrodes conforming to the hat. A circuit board having a low-noise integrated circuit amplifier may be mounted thereon. Each electrode uses a plurality of metal conductive fingers which protrude through the hair to the scalp and provide multi-contact sites on the scalp for each electrode. The tips of each electrode contact the user's scalp to provide a redundancy of contacts for each electrode.

Abstract: A magnetoencaphalogram (MEG) detects the neuromagnetic brain signals of a subject by bringing a set of magnetic sensors, preferably SQUIDs (superconducting quantum interference device), close to the scalp of the subject. The adverse effect of environmental magnetic noise is reduced by using a second set of magnetic sensors which are placed near the subject. The system includes a bandpass filter, to divide the signals from the various sensors into predetermined frequency bands, and a computer to provide a least squares noise component estimate of the noise from each brain wave sensor and to calculate therefrom a filtered brain wave signal having reduced noise.

Abstract: A method and system in Nuclear Magnetic Resonance (NMR) medical imaging systems corrects for three-dimensional distortions arising from the apparatus and patient specific distortions using a phantom and a helmet, both of which have fiducial markers in a three-dimensional matrix. The positions of the phantom and helmet fiducial markers are automatically detected and compared in a computer system which uses image transform algorithms to correct for the various distortions.

Abstract: In a medical electroencephalographic EEG system, a hat is placed on the head of the patient. The hat contains a plurality of electrodes conforming to the hat. A circuit board having a low-noise integrated circuit amplifiers may be mounted thereon. In one embodiment each of the electrodes has a number of flexible and elastic fingers, for example 2-16 gum rubber fingers, having a conductive tip at the end of each finger, or flexible fingers made entirely of conductive material. In another embodiment the multi-contact electrode uses fingers which are rigid and connected to a spring-loaded plate. The tips contact the patient's scalp, without conductive gel or liquid, to provide a redundancy of contacts.

Abstract: A method and system is provided for the analysis of a human subject's brain wave activity on a statistical basis using a digital computer. The location of portions of the subject's brain and the location of at least 32, and for example 265, external scalp sensors are digitally recorded and stored in computer memory. The subject receives a set of stimuli which evoke brain waves (evoked potential EP or evoked magnetic fields EF) which, along with the location data, are statistically analyzed to indicate the brain sites giving rise to the activity. The brain site activity, and the time interrelationships of brain waves as they progress between brain sites, are displayed on a three-dimensional model or other three-dimensional perspective display.