Search PubMed⌕ Search

Biomedical subjects

J Hasan

Publications and source records attributed to J Hasan.

At least 55 records · Page 3Linked to original sources
PubMed1987

Trunk muscle function and low back disorders: a ten-year follow-up study.

Low back disorders and trunk muscle function were studied by questionnaire, interview, clinical examination, and performance tests in 902 employees in the metal industry. The survey was repeated after a 10-yr interval for 654 persons. For those who were allowed to participate in the muscle function tests, the prevalences of clinical findings in the low back and of chronic lumbosacral disease were inversely associated with muscle function in both cross-sectional studies. This association seems not to be explained by the interference of pain with muscle function tests. There was no association between muscle function at baseline and either the 10-yr incidence of chronic low back disease or the development of low back symptoms. Men with poor muscle function at baseline had a slightly elevated risk for the appearance of clinical findings at follow-up. There was an inverse association between the clinical findings at baseline and muscle function at follow-up. The association between low back disorder and trunk muscle function seems to result from an effect of the former on the latter, but poor muscle function may also contribute to the risk of disorder.

Back Pain↗
PubMed1987

A study of sleep patterns on two Finnish icebreakers, ambulatory recording and automatic analysis.

The effects of noise and vibration on sleep in Finnish ice-breaking ships were studied in healthy volunteer workers and a control group. EEG, EOG and EMG were recorded by means of portable tape recorders. The recordings were analysed by an automatic hybrid system. Both sleep stage parameters and the quantities of single EEG waveforms were used for the evaluation of the sleep quality. Measurements were made before, during and after the ice-breaking season in the winter. Higher amounts of wakefulness and sleep stage 1, and lower amounts of delta and theta activity were found on a night during the ice-breaking season, compared with a night after the season. This was interpreted as indicating a "lightening" of sleep, caused by noise and vibration. No differences between the nights before and during the ice-breaking season were observed. The crew members had an appr. 1 h shorter Time In Bed and Sleep Period Time than the controls also on the nights studied ashore. Because of the small number of subjects the results are not conclusive, even though statistically significant differences were obtained. The delta activity in seconds/minute seems to be a more informative measure than the percentages of the sleep stages S3 and S4. The possibility of using the theta activity as a measure of the length of sleep should be further investigated.

Adult↗
PubMed1987

Occupational class, psychosocial stress and morbidity.

The association between stress and morbidity was studied in an industrial population, which consisted of both white-collar and blue-collar workers (n = 902). Information about living and working conditions, health behaviour, mental well-being and morbidity were obtained by questionnaires, interviews, clinical examinations, and physiological and biochemical measurements. The same cohort was re-examined after five and ten years. Comparison of occupational classes showed consistently that living and working conditions, psychosocial stress, and health and sickness behaviour were more deleterious among blue-collar workers and their morbidity and mortality rates were higher than among white-collar workers. The effect of stress on health was examined both cross-sectionally and longitudinally. Psychosocial stressors at work were related to mental strain, perceived health, and absenteeism. Stress symptoms were strongly associated with perceived health, locomotor symptoms, smoking, drinking, and absenteeism. None of the stress indicators were related to blood pressure. In the follow-up the baseline indicators of stress predicted future chronic illness and angina pectoris, but not hypertension or myocardial infarction. Blood pressure changes were not related to psychosocial factors. Stress did not predict mortality in the ten year follow-up. The study suggests that psychosocial stress is mostly related and may be causally linked to such indicators of morbidity as perceived health, bodily symptoms and sickness behaviour. The aetiological contribution of stress to biologically defined morbidity may be weak.

Attitude to Health↗
PubMed1983

Differentiation of normal and disturbed sleep by automatic analysis.

The main purpose of the present study was to develop an automatic hybrid system and evaluate its performance in the differentiation of normal and disturbed sleep. The study was carried out in roughly the following steps: At the beginning the quantity of five EEG waveforms, delta, theta, alpha, sigma and beta were examined with respect to sleep stages and their temporal distributions and inter-relationships throughout the nights in young 20-22 year-old, healthy individuals. These data were used as a basis for the choice of parameters for a sleep stage scoring program. Secondly, the sleep stage scoring software was developed using as test material three subject groups: about 10 years older controls, anonymous alcoholics and chronic alcoholics in the withdrawal phase. The last group was examined on two occasions, first in the initial withdrawal and then after two weeks' abstinence between the recordings. The sleep stage scoring program was evaluated in comparison with a visual sleep stage determination and its performance was also tested on the young normals. Attention was paid to three main points: First, how well does an automatic system imitate the visual classification of a human subject, when both the human and the computer classifications are compared side by side at a 20 s epoch level? Second, even if this comparison did not show a satisfactory agreement, could the computer classification still replace the visual sleep stage scoring when the objective is to describe the neurophysiological characteristics of the human whole-night sleep process or differentiate between normal and disturbed sleep. For this purpose it was examined, whether the values for the sleep stage parameters obtained by visual classification corresponded to those obtained by computer scoring and whether the differences found between the groups by manual methods could also be obtained by computer classification. The third goal was to see whether other measures than parameters received by sleep stage classification could be used for the differentiation between normal and disturbed sleep. In the present work only EEG waveform parameters and body movement activity were studied with this in mind. It was found that sleep can satisfactorily be classified in stages by automatic analysis if it is not markedly disturbed. The percentage agreement obtained for the three groups having practically normal sleep (young normals appr. 80%, older normals 77% and anonymous alcoholics 75%) was satisfactory and sufficient for clinical and experimental work.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMedDate not supplied

A computerized analysis system for vigilance studies.

A digital signal analysis system for vigilance studies is presented. The analysis is based on adaptive segmentation, band pass filtering, nonlinear eye movement detection and rule-based decision making. A preliminary evaluation of seven subjects falling asleep showed that the system is able to detect small vigilance fluctuations reliably.

Artifacts↗