Abstract: A reusable appliance for acquisition from a patient of EEG signals comprising a micro-miniature, micro-power, low noise multi-channel data-acquisition system powered by a fiber optic illuminator and photovoltaic cell thus eliminating the need for inductively coupled power converters. The appliance also uses disposable EEG electrodes which are similar in size and very low cost.

Abstract: A patient module comprising an 8 channel EEG pre-amplifier whose signal acquisition and processing characteristics are optimized for use in the operating room and intensive care unit. This patient module comprises at least an optimized multistage input filter, an optimized input stage circuit topography, ultra-isolation, oversampling, a multiplexer inter-sample charge dump, and high performance low-frequency-enhanced shielding.

Abstract: A system which classifies patients according to their level of awareness or consciousness using measures derived solely from electroencephalograph (EEG) signals. The system comprises multiple observes of characteristics of signals, including artifact detectors, especially magnitude artifact detectors, eye blink detectors, stationarity/RMS detectors, slew rate detectors, and burst suppression detectors, and determination of power in certain frequency bands. The system produces a single derived probabilistic measure of conscious awareness called the patient state index (PSI) and displays values of trends in that index and values of an artifact index, an EMG index, and a suppression ratio in order to give the operator current information on the quality of the signal input. The PSI is derived from a statistical analysis using empirically derived population norms and other parameters.

Abstract: A medical appliance for acquiring EEG signals from a patient's head applied solely to the patient's forehead comprising a frontal array of hydrogel electrodes. The appliance also comprises a clear dielectric layer, an electromagnetic shield layer, and signal traces from the electrodes to an appliance connector. The electrodes are generally rectangular in shape and are located at frontal positions according to the International 10-20 System. The electrodes further comprise a retaining mechanism and internal volcano tips to abrade the outer layers of the dermis for improved electrical contact and lower contact impedance.

Abstract: A system which classifies patients according to their level of awareness or consciousness using measures derived solely from electroencephalograph (EEG) signals. The system comprises multiple observers of characteristics of signals, including artifact detectors, especially magnitude artifact detectors, eye blink detectors, stationarity/RMS detectors, slew rate detectors, and burst suppression detectors, and determination of power in certain frequency bands. The system produces a single derived probabilistic measure of conscious awareness called the patient state index (PSI) and displays values of trends in that index and values of an artifact index, an EMG index, and a suppression ratio in order to give the operator current information on the quality of the signal input. The PSI is derived from a statistical analysis using empirically derived population norms and other parameters.

Abstract: This invention defines a system for monitoring the brain activity of a human patient under anesthesia in order to determine the patient's level of consciousness. The system uses a plurality of receptors which are mounted in predetermined anatomical positions on the patient's head. The receptors are secured by adhesive foam patches. The appliance fits snugly to the head with the aid of self-adjusting strip that carry imbedded electrical circuitry for the receptors. Electrical connectivity in locations where scalp hair is most likely to be present is improved by the use of braille-tip electrodes fitted with large gel reservoirs.

Abstract: This invention defines a system for monitoring the brain activity of a human patient in order to monitor a patient's brain electrical activity. The system uses a plurality of receptors which are mounted in predetermined anatomical positions on the patient's head. The receptors are secured by adhesive foam patches. The appliance fits snugly to the head with the aid of self-adjusting strap that carry imbedded electrical circuitry for the receptors. Electrical connectivity in locations where scalp hair is most likely to be present is improved by the use of braille-tip electrodes fitted with large gel reservoirs.