Some sequential, distribution free pattern classification procedures with applications
Sequential, distribution-free pattern classification procedures tested on Gaussian and EEG patterns
Poage, J. L.↗
SEARCH · Engineering Papers
Results for “EEG”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Analysis of 10 minutes of physiological data from the Biosatellite III from lift-off to orbital insertion
Monkey physiological responses from lift-off to orbital insertion, showing EEG and EMG arousal reactions, motion sickness development, cardiovascular and respiratory changes
Adey, W. R.↗
Sleep and wake states in the Biosatellite III monkey - Visual and computer analysis of telemetered electroencephalographic data from earth orbital flight
Biosatellite 3 monkey sleep and wake states based on visual and computer analysis of telemetered EEG data from earth orbital flight
Adey, W. R.↗
Digital computer analysis of neurophysiological data from Biosatellite III
Biosatellite 3 neurophysiological data analysis by digital computer presenting maps of parietal cortex spectra, responsive states transient changes, circadian rhythms and EEG activity
Adey, W. R.↗
Learning from the biological viewpoint
Biological learning, considering EEG wave activity association with structural change underlying information storage in cerebral tissue
Adey, W. R.↗
Tracking variations in the alpha activity in an electroencephalogram
The problem of tracking Alpha voltage variations in an electroencephalogram is discussed. This problem is important in encephalographic studies of sleep and effects of different stimuli on the brain. Very often the Alpha voltage is tracked by passing the EEG signal through a bandpass filter centered at the Alpha frequency, which hopefully will filter out unwanted noise from the Alpha activity. Some alternative digital techniques are suggested and their performance is compared with the standard technique. These digital techniques can be used in an environment where an electroencephalograph is interfaced with a small digital computer via an A/D convertor. They have the advantage that statistical statements about their variability can sometimes be made so that the effect sought can be assessed correctly in the presence of random fluctuations.
Prabhu, K. S.↗
Research program for experiment M133
The development of the automatic data-acquisition and sleep-analysis system is reported. The purpose was consultation and evaluation in the transition of the Skylab M133 Sleep-Monitoring Experiment equipment from prototype of flight status; review of problems associated with acquisition and on-line display of data in near-real time via spacecraft telemetry; and development of laboratory facilities and design of equipment to assure reliable playback and analysis of analog data. The existing prototype system modified, and the changes improve the performance of the analysis circuitry and increase its reliability. These modifications are useful for pre- and postflight analysis, but are not now proposed for the inflight system. There were improvements in the EEG recording cap, some of which will be incorporated into the flight hardware.
Frost, J. D., Jr.↗
Acquisition of electroencephalographic data in a large regional hospital - Bringing the brain waves to the computer.
This paper describes a complete electroencephalographic acquisition and transmission system, designed to meet the needs of a large hospital with multiple critical care patient monitoring units. The system provides rapid and prolonged access to a centralized recording and computing area from remote locations within the hospital complex, and from locations in other hospitals and other cities. The system includes quick-on electrode caps, amplifier units and cable transmission for access from within the hospital, and EEG digitization and telephone transmission for access from other hospitals or cities.
Low, M. D.↗
Sleep-wake cycle of an unrestrained isolated chimpanzee under entrained and free running conditions.
Biorhythmic patterns of EEG activity - the sleep-wake cycle and the sleep cycle - were investigated in an unrestrained chimpanzee subjected to 30 days of isolation in a 4-ft cubical cage placed in a high performance sound isolation chamber. The animal received 10 days of 12 hours of light and 12 hours of dark, then 10 days of continuous light, followed by 10 more days of 12 hours of light and 12 hours of dark. The circadian sleep-wake rhythm and the wake and sleep phases of this rhythm during entrained and free running conditions were analyzed in terms of duration. The awake and nonREM sleep and REM sleep stages were also analyzed. In addition, the mean duration of the sleep cycle of the sleep phase was computed.
Mcnew, J. J.↗
Electroencephalographic and behavioral effects of nocturnally occurring jet aircraft sounds.
The present research presents data relative to the objective evaluation of the effects of a specific complex auditory stimulus presented during sleep. The auditory stimulus was a jet aircraft flyover of approximately 20-sec duration and a peak intensity level of approximately 80 dB (A). Our specific interests were in terms of how this stimulus would interact with the frequency pattern of the sleeping EEG and whether there would be any carry-over effects of the nocturnally presented stimuli to the waking state. The results indicated that the physiological effects (changes in electroencephalographic activity) produced by the jet aircraft stimuli outlasted the physical presence of the auditory stimuli by a considerable degree. Further, it was possible to note both behavioral and electroencephalographic changes during waking performances subsequent to nights disturbed by the jet aircraft flyovers which were not apparent during performances subsequent to undisturbed nights.
Levere, T. E.↗
Biotelemetry and computer analysis of sleep processes on earth and in space.
Developments in biomedical engineering now permit study of states of sleep, wakefulness, and focused attention in man exposed to rigorous environments, including aerospace flight. These new sensing devices, data acquisition systems, and computational methods have also been extensively applied to clinical problems of disordered sleep. A 'library' of EEG data has been prepared for sleep in normal man, and characterized for its group features by computational analysis. Sleep in an astronaut in space flight has been examined for the first and second 'nights' of space flight. Normal 90-min cycles were detected during the second night. Sleep patterns in quadriplegic patients deprived of all sensory inputs below the neck have indicated major deviations.
Adey, W. R.↗
Assistance to NASA in biomedical areas of the technology utilization program
The applications of aerospace technology to biomedical research are reported. The medical institutions participating in the Biomedical Applications Program are listed along with the institutions currently utilizing the services of the Southwest Research Institute Biomedical Applications Team. Significant accomplishments during this period include: ultra-low bandpass amplifier for gastro-intestinal electric potentials; non-encumbering EEG electrode assembly suitable for long term sleep research; accurate cardiac telemetry system for active subjects; warning system for the deaf; tracking cane for the blind; and an improved control mechanism to expand the self-sufficiency of quadriplegics.
Culclasure, D. F.↗
Application of frequency discrimination technique to the analysis of electroencephalographic signals.
A frequency discrimination technique is described which has proved to be effective in measuring the entrainment phenomenon in EEG signals. The validity of a narrow-band-process model used to characterize the signals is demonstrated. The technique (realized by an inexpensive device described elsewhere) is shown to provide a means of studying the synchronization phenomenon as related to alertness.
Lai, D. C.↗
Sleep mechanisms: Sleep deprivation and detection of changing levels of consciousness
An attempt was made to obtain information relevant to assessing the need to sleep and make up for lost sleep. Physiological and behavioral parameters were used as measuring parameters. Sleep deprivation in a restricted environment, derivation of data relevant to determining sleepiness from EEG, and the development of the Sanford Sleepiness Scale were discussed.
Dement, W. C.↗
Correlation of hippocampal theta rhythm with changes in cutaneous temperature
A possible role for the hippocampus in alerting an animal to changes in cutaneous temperature was examined. Following local warming or cooling of the ears of unanesthetized, loosely restrained rabbits, theta waves (4-7 Hz EEG waves) were recorded from electrodes straddling the hippocampus. The onset of the hippocampal theta rhythm was correlated with changes in cutaneous temperature, an observation consistent with studies indicating that the theta rhythm is a nonspecific response evoked by stimulation of several sensory modalities. Additional data from cats and rabbits were correlated with specific neurons within the hippocampus, namely pyramidal cells. Post stimulus time histograms obtained by excitation of the dorsal fornix were interpreted in terms of excitatory and inhibitory inputs to pyramidal cells. Thus, the theta rhythm, which appears to be evoked by changes in cutaneous temperature, can be related to a specific type of hippocampal neuron which is in turn connected with other areas of the brain involved in temperature regulation.
Horowitz, J. M.↗
On hemispheric differences in evoked potentials to speech stimuli
Confirmation is provided for the belief that evoked potentials may reflect differences in hemispheric functioning that are marginal at best. Subjects were right-handed and audiologically normal men and women, and responses were recorded using standard EEG techniques. Subjects were instructed to listen for the targets while laying in a darkened sound booth. Different stimuli, speech and tone signals, were used. Speech sounds were shown to evoke a response pattern that resembles that to tone or clicks. Analysis of variances on peak amplitude and latency measures showed no significant differences between hemispheres, however, a Wilcoxon test showed significant differences in hemispheres for certain target tasks.
Galambos, R.↗
A sequential nonparametric pattern classification algorithm based on the Wald SPRT
A sequential nonparametric pattern classification procedure is presented. The method presented is an estimated version of the Wald sequential probability ratio test (SPRT). This method utilizes density function estimates, and the density estimate used is discussed, including a proof of convergence in probability of the estimate to the true density function. The classification procedure proposed makes use of the theory of order statistics, and estimates of the probabilities of misclassification are given. The procedure was tested on discriminating between two classes of Gaussian samples and on discriminating between two kinds of electroencephalogram (EEG) responses.
Poage, J. L.↗
Short-range biotelemetry system
Compact VHF transmitter relays EKG, EEG, and EMG data to receiver located over twenty-five feet away. Device can be used to monitor postoperative patients without cumbersome wires.
Lorentz, R.↗