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Biomedical subjects

A Janocha

Publications and source records attributed to A Janocha.

8 recordsLinked to original sources
PubMed2001

[The effects of work in an air-conditioned cabin and stay in a resting chamber on blood pressure and heart rate of operators employed in deep copper mines].

This paper is part of a wider comparative study of the heart rate, blood pressure, external and core temperature in operators of self-propelled mining machines with and without air-conditioning cabins. Two groups, each of ten operators, characterised by the similar age and duration of employment, stayed for 20 min a specially prepared resting chamber with much more advantageous microclimatic conditions. The results of our examinations (Holter heart rate and continuous blood pressure recordings, external and core temperature measurements) revealed that during the work (particularly during the increased work-load) all parameters recorded were significantly lower in air-conditioning cabins as compared with the group working without air-condition. In both groups, a complete restitution of the heart rate and blood pressure was observed after a 20-min stay in the resting chamber. During the work, a statistically significant increase in the external temperature was found in both groups of operators, whereas the increase in the core temperature was observed only in operators working without air-condition. After a 20-min stay in the resting chamber, a complete return to the normal temperature was noted only in operators working in air-conditioned cabins.

Adult↗
PubMed1998

[The effect of the gender of the examined subjects on the course of the visual potentials evoked by the checker board pattern stimulation].

A goal of the present work was to analyze the correlation between a course of visual potentials elicited with the pattern stimulation and gender of the examined subjects. VEPs (Visual Evoked Potentials) recordings were performed using STELLA system in a group of 65 healthy adult subjects, with the age ranging from 18 to 70 years, consisting of the age-matched subgroups of 37 females and 28 males, applying a checkerboard as the pattern-reversal stimulation. In result of the analysis of the individual VEPs parameters, no effect of gender on the P100 latency was found. The discrepancies in the course of VEPs concerned P100 amplitudes, likewise a difference of the maximum and minimum amplitude, which proved to be significantly greater in the recordings collected from the left hemisphere in women than in men. Moreover, there was the appreciably greater symmetry between the responses registered over the both cerebral hemispheres, reflected by the higher correlation coefficients, in the male subgroup compared to the female subjects. The herein reported differences in the VEPs characteristics recorded in the male and female subjects can be elucidated on the ground of the documented discrepancies regarding the structural and functional cerebral organisation in women and men with regards to visual perception.

Adult↗
PubMed1997

[The influence of computer work on reaction time and accuracy in VDT operators].

The study of simple reaction to light and sound, and differential reaction was carried out on the group of VDT operators (n = 62) and the group of persons not involved in VDT operation (n = 38). Concentration ability was tested with Couve's test twice a day, i.e. before and after work. In the analysis of the results, reaction time and the accuracy of psychomotor trials measured by the number of errors committed were considered. None of the research models disclosed statistically significant differences between the average figures calculated for the VDT operators and the other group. The figures registered before and after work in each group were not significant either. Both group also failed to show the influence of age on the duration of reaction. The ability to concentrate was lower among operators than among those not involved in VDT operation, and it decreased after work, especially in the oldest subgroup.

Adult↗
PubMed1991

[Evaluation of the reliability of freight elevator operators].

The study involved 58 workers employed at winding machines. Their reliability was estimated from the results of psychomotoric test precision, condition of the vegetative nervous system, and from the results of psychological tests. The tests were carried out at the laboratory and at the workplaces, with all distractive factors and functional connection of the work process present. We have found that the reliability of the workers may be affected by a variety of factors. Among the winding machine operators, work monotony can lead to "monotony syndrome". Among the signalists , the appreciation of great responsibility can lead to unpredictable and non-adequate reactions. From both groups, persons displaying a lower-than-average precision were isolated. All those persons demonstrated a reckless attitude and the opinion of their superiors about them was poor. Those persons constitute potential risk for the reliable operation of the discussed team.

Adult↗
PubMedDate not supplied

[Exercise test in the neurotic patients].

While testing neurotic patients it was noted that almost all of their complaints concerned physical weakness, easy tiredness, chest pain, heart beating and palpitation. In order to evaluate objectively their physical efficiency, the patients were subjected to exercise test on a treadmill, their ECG, HR and blood pressure being monitored. The exercise test was carried out twice, i.e. before and after 3-month psychotherapy. The average physical efficiency coefficient before treatment was significantly lower than after the treatment, but repolarization disorders were significantly higher before the treatment. ECG analysis proved non-specific repolarization changes induced by excitability of sympathetic system. 8 patients showed changes in ST-T before the treatment and 4 persons after it. Another kind of changes (that appeared in 14 cases before the treatment) were extrasystoles mainly supraventricular. After psychotherapy they were noted only in 1 case. The analysis of HR and blood pressure proved a significantly higher HR and lower blood pressure before the treatment. The obtained results may become an argument supporting the functional character of the changes mentioned.

Adult↗
PubMedDate not supplied

[The evaluation of central visual fatigue in computer terminal users by visual evoked potentials].

Visual evoked potentials (VEPs) were recorded in a group of 20 operators aged 25-45 years during two sessions, before and after a 5-hour work at computer terminals, in order to assess visual system fatigue. The outcomes were referred to the norms established for the age-matched population of 30 subjects not exposed to professional contact with computers. Most of the examined operators suffered various complaints concerning not only the organ of vision but the central nervous system as well. VEPs were elicited by means of monocular stimulation using the reversal checkerboard pattern and recorded simultaneously from the scalp electrodes placed over the right and the left cerebral hemisphere. Only recording acquired after finishing of a working day demonstrated significant statistically abnormalities of the VEPs waveforms, which suggests their transient character. The changes mentioned above included prolongation of peaks P100 and N2 latency with concomitant attenuation of their amplitudes and a decrease of the correlation coefficient values for the recordings from the hemispheres. The preliminary findings presented in this paper seem to justify a conclusion that the non-invasive VEPs method can be considered as the objective indicator of the central visual fatigue induced by the workload at computer terminals.

Accommodation, Ocular↗