PubMed Health⌕ Search

Biomedical subjects

V V Dementienko

Publications and source records attributed to V V Dementienko.

9 recordsLinked to original sources
PubMed2001

Automatic checkout systems to monitor driver's vigilance.

A concept for designing automatic checkout systems to prevent drivers from falling asleep is presented. It is shown that such systems should use the frequency of electrodermal reactions (EDR), which is governed by changes in skin resistance. Such changes have a time constant of several seconds. To detect these reactions, a special technique was developed. Experimental investigations yielded the quantitative characteristics of EDR changes associated with decreased vigilance. It was found that, when a person started to fall asleep, the EDR frequency diminished. An EDR-based system was developed to assess the alertness level. Such a system may be employed to prevent drivers from falling asleep.

Accidents, Traffic↗
PubMed1989

[Dynamic radiothermography of the human liver].

In the experiments on the volunteers it has been shown that the method of dynamic radiothermography is quite sensitive for measurement of temperature fluctuations in human body. This method makes it possible to register the changes of the temperature in inner organs using the probes placed on body surface. Some volunteers drank hot or cold water, some volunteers drank glucose solution, others got the dose of low laser radiation upon the liver. In the case of cold water liver temperature fell, in all other cases liver temperature rose. The results of the dynamic radiothermography of human liver allow us to suppose that low laser radiation of this organ leads to the stimulation of liver blood flow.

Adult↗
PubMedDate not supplied

[The characteristics of the electrodermal activity during changes in the level of human wakefulness].

The wake-drowsiness transition during the performance of a monotonous psychomotor test was studied using polygraphic recording, with particular emphasis on changes in the electrodermal activity (EDA) and occurrence of electrodermal reactions (EDR). It was found that decrease in wakefulness was accompanied by a drop of the EDA. The EDR gradually disappeared for several minutes and did not reappear without activation; their dependence on sex and individual features of a subject significantly increased. It is suggested that discrepancies in the experimental results of psychophysiological studies with EDA may be explained by an insufficient control of the subject's alertness throughout the experiment. Examples of such discrepancies are given: disagreement of sex differences in the EDA, differentiation between EDA-labile and EDA-stable persons, on a possibility of recording the "emotional" EDA from different parts of human body etc. The ways of reproducibility of the results are discussed including the recording of several wake-drowsiness transitions and better recognition of the EDR.

Adolescent↗
PubMedDate not supplied

[The electrodermal indices of the subjective perception of performance errors during drowsy changes in consciousness].

The study was aimed at searching for objective criteria of subject's perception of errors in performance due to drowsiness and estimating the time between the onset of errors and the moment of their awareness. Healthy subjects (n = 64) with the pronounced EEG alpha were examined under conditions without sleep deprivation. Experiments (n = 280) lasted for 40 min. During the experiments, the EEG, EOG, EDR, EKG, and button pressings were recorded and subject's reports were registered. The subjects were waken up after the onset of errors or 20 min after the beginning of the performance independently of errors. The error onset was shown to be preceded by the EEG "drowsy pattern" and decrease in the rate of spontaneous EDR. The performance reappearance after the error was accomplished by alpha-rhythm independently from error awareness. The interrogation of subjects after the error and activity revival demonstrated a correlation between the error subjective perception and appearance of the EDR. The interval between the error and the first following EDR (mean 10.1 s) was significantly (p < 0.001, t-test for dependent samples) shorter than the interval between the error and the last preceding EDR (mean 69.8 s). It is suggested that the subjective perception of an error is a significant endogenous stimulus, which evokes the orienting response and accompanying sympathetic activation.

Adolescent↗