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Biomedical subjects

H Luczak

Publications and source records attributed to H Luczak.

At least 19 recordsLinked to original sources
PubMed2001

Ergonomics as integrating constituent in occupational safety and health--past, present, and future.

Ergonomics as a discipline was in the past, is in the present, and will be in the future, an integrating constituent in occupational safety and health (OSH). This statement is based on the self-conception of ergonomics and the level concept of human work. It is further supported by the results of about 120 interviews with German experts involved in research projects of the last 2 decades and the results of a quantitative analysis of international literature. The most important themes of past research are compiled and a prognosis of research themes of the future is given. The future role of ergonomics is exemplified by its contributions to the further development of OSH management systems.

Ergonomics↗
PubMed2001

International comparison of occupational safety and health research--a review based on published articles.

A comparison of international literature in occupational safety and health (OSH) research over the years from 1980 to 1998 was conducted. The comparison is based on the different languages of the over 35,000 articles, which were collected from different databases. The distribution of languages in the analyzed data has to be considered carefully with respect to the original purpose of the data collection and the specific role of the international publication language, English. The comparison shows that in several aspects OSH research does not differ in different publication languages. In some methodological aspects, and in specific objects of research, differences between articles published in different languages can be found.

Accidents, Occupational↗
PubMed1991

Work under extreme conditions.

Extreme conditions are defined in terms of deviation from the norm, and the mismatch between capacity and demand. Analysis of ergonomic job description data revealed the predominance, through their frequent occurrence, of extreme conditions. Extreme work environment conditions, such as climate, acceleration, and air pressure, are discussed. Task and error-concepts for workers operating under extreme workload are investigated, with reference to Chernobyl, stress-strain concepts for ATC, college examinations and shiphandling.

Acceleration↗
PubMed1988

Cloning of two chloramphenicol acetyltransferase genes from Clostridium butyricum and their expression in Escherichia coli and Bacillus subtilis.

Two non-homologous chloramphenicol (Cm) acetyltransferase (CAT) genes, designated catA and catB, were cloned from Clostridium butyricum type strains and characterized by restriction mapping. Both genes are efficiently expressed in Escherichia coli and Bacillus subtilis. In contrast to analogous genes from staphylococci and bacilli, gene expression is not dependent on induction by Cm. The genes are considered as chromosomal, since no association with endogenous plasmids was detectable. Southern hybridization revealed a homology between catA and the staphylococcal Cm resistance plasmid, pC194. The subunit size of the clostridial CAT enzymes expressed in E. coli was determined as 22.5 kDa (catA) and 24 kDa (catB), respectively. The C. butyricum cat genes provide potentially useful selection markers for the construction of cloning vectors from cryptic clostridial plasmids.

Bacillus subtilis↗
PubMed1985

Improved "active" electrodes for recording bioelectric signals in work physiology.

Conventional recording techniques of bioelectric signals using surface electrodes are often very sensitive to artefacts, in particular when carrying out physiological investigations in ergonomics and sports. An "active" electrode, by means of impedance-converting-amplification, was developed to reduce motion artefacts in recording of bioelectrical signals. The application of these electrodes on the skin surface does not differ from that of conventional electrodes. The circuit elements of the impedance-converting-preamplifier, including a power-supply, are placed in a small portable housing. A qualitative comparison between conventional Ag/AgCl electrodes and "active" electrodes in ECG and EMG recordings with artefact simulation shows a high degree of artefact suppression for the "active" electrodes.

Electrocardiography↗
PubMed1984

[Objectivity, validity and reliability of determination of recovery times following exhaustion trials in heavy dynamic muscle work from time series of heart rate].

Records of heart rate after 152 experiments with exhaustion of three male subjects were rated by three experts to determine the end of the recovery phase. Inter-rater-reliability of recovery times vary between 0.87-0.97 according to the method of calculation. An algorithm for the identification of the end of recovery is developed by approximation of the expert-ratings. The corresponding rater-reliability of the algorithm is 0.9. A stepwise multiple regression shows, that most of the variance of recovery times is explained by heart rate at the end of the working phase (63.8%) and by the conditions of the rest phase (18.9%), whereas the stress conditions in the working phase, as type (10.6%), level (20%) and duration (0%) of stressors are concerned, have less explanatory value. These results differ from the literature. The differences are discussed with respect to different criteria for "fatigue" and "recovery".

Adult↗
PubMed1982

Ergonomics investigations of work-places in a police command-control centre equipped with TV displays.

Ergonomics experiments were performed in a police command-control centre using computer controlled text processing systems with three alternative input devices: function keys, a light pen and a touch panel. A group of 14 operators was examined while using the alternative devices. Significant differences were found between the devices in terms of the following: sensory and motor activities, local muscular strain, transgressions of tolerance limits for 4-hour work sessions, and increases in heart rate. Suggestions for redesigning the control centre are given using anthropometric analysis. The paper also shows the relation between the sub-optimal design of a work system and the resulting strain.

Journal Article↗
PubMed1979

[Ergonomical studies about the superposition of control activity and mechanical vibration (author's transl)].

The effects of combined stresses due to control activity and vertical mechanical vibration on man are analysed. In the first part, the processes in the human being at those superposed stresses are shown in a deterministic way, starting from morphological and physiological facts, which leads to a division of the organismic data processing in the fields of information reception, central information processing and information output. Hypothesis of the effects of vibration in the parts of information reception and information output as well as indications to measurable variables at laboratory experiments can be deduced from the model formulation. In the experimental part about factorized laboratory experiments with combined stresses consisting of an ideal-typical compensatory-tracking-task and mechanical vibration is reported, which can be divided into short-time experiments with measurement of the statistical control-factor and perseverance experiments with additional measurements of physiological variables. As established in the first part, influences of vibration in the regions of information reception and information output were found as well as thresholds for the performance-reducing effects of mechanical vibrations. The magnitudes of the thresholds are dependent on the task difficulty.

Ergonomics↗
PubMed1978

Ergonomics in the design and evaluation of a system for "postal video letter coding".

In co-operation with the German Central Post Office for Technological Development, the authors designed and investigated the task of and workplace for "Postal video-letter-coding". Experiments including measures of performance, errors, heart rate, arrhythmia, EMG's, and EOG's were used to experiment with variations in the design of displays, codes, keyboards, shifts and rest pauses. As a result of this work the following recommendations have been made by the authors and accepted by the authorities: An optimal display configuration has been developed with two vertically arranged tv displays. Coding-rules are to be simplified by modifications of the postcode. The usual flat keyboard has been replaced by an inclined and angular keyboard. Night-shifts must be avoided because of the tedious nature of the task. A work-rest-schedule of 50 min work and 10 min rest is proposed. In 1978 the complete work-system-design will be introduced in the standard postal service.

Journal Article↗
PubMed1976

[Adaption of subjects in field studies of informatory working conditions (author's transl)].

Processes of adaption in measurements of performance - cycle-times, variance of cycle-times, informatory component of time and errors - and of physiological strain - electromyograms of musculus extensor digitorum and musculus rhomboideus, horizontal and vertical electrooculogram, heart rate and heart rate variability - are presented and described in type and frequency. Simultaneous reactions and successive reactions of measured variables in dependance of shift-time and of days are described. They are classified according to the causes "exercise" and "emotional habituation" and discussed in a model "experimenter - experimental situation".

Adaptation, Physiological↗