PubMed Health⌕ Search

Biomedical subjects

K W Müller

Publications and source records attributed to K W Müller.

7 recordsLinked to original sources

[Application of the Isler and Ganz classification of pelvic ring fractures in clinical practice].

The classification of pelvic fractures proposed by Isler and Ganz was applied to 152 patients. On the basis of this experience, the following conclusion were drawn. 1. It is possible to classify all pelvic ring injuries by dividing them in lesions of the anterior and of the posterior ring segment. 2. The classification requires a thorough examination; often a CT scan is needed. The original classification of 9 out of 18 patients based on X-ray morphology had to be revised after CT examination. 3. Once the pelvic injury is definitely classified the mode of therapy is determined as well.

Adult↗

Local muscular strain dependent on the direction of horizontal arm movements.

Manual material handling still plays an important role in assembly work as well as in the service industry. By means of an ergonomic layout of working places, the effects of disadvantageous working conditions, especially static load resulting from unfavourable postures of the body as well as unnecessary physiological cost arising from body movements may be avoided. In this context knowledge about the optimum directions of horizontal arm movements is fundamental. Therefore by means of advanced methods of multi-channel electromyography (EMG) and applying computer assisted evaluation methods, physiological responses to one-handed horizontal material handling in a sitting position were recorded. In order to obtain myoelectric signals from the most important task-relevant muscles out of more than 40 muscle groups of the hand-arm-shoulder-system, preceding research was done also aiming at standardized lead positions for surface EMG. Groups of five young females each participated in a series of successive experiments, in which the direction of movements of the left arm was varied. The subjects worked without and with an external load imposed by weights of 0, 1, 2 and 4 kg. The movements between 20 degrees and 230 degrees--measured from the frontal plane of the subjects--included working from ahead and from behind. The lifting distance was 38 cm starting from different outward points within the reach to a fixed point near the body. Also in one test series the handling frequency was varied between 12, 24 and 48 lifts per minute. Assessment of the physiological cost by electromyographic activities (EA), especially the determination of the most stressful and least expensive directions of repetitive horizontal movements, was more effective when differentiating static and dynamic portions of muscular strain than common means of EA.

Adult↗

A concept for detecting unexpected changes in the environment early.

A project was established under the auspices of the German Federal Ministry of Research and Technology with the task of developing a concept for the early recognition of signals for unexpected deleterious changes in the environment. Predictive assessments of products (e.g., chemicals) and technologies as regards their potential environmental impacts contain numerous sources of error and uncertainties. Therefore, appropriate observation systems are needed in order to detect unexpected developments in the environment and in human health. Long-term storage of samples (environmental specimen banking) is the third basic activity that must be undertaken within an early warning system. When monitoring the environment for unwanted changes, it is not sufficient to trace some individual agents, preselected for their well-known capacity to inflict harm. The following avenues of identifying symptoms of change in the environment were identified: development and deployment of "key indicators"; acquisition and correlative treatment of conventional monitoring data from different sources; and execution of concise studies in environmental problem areas. Key indicators are defined as scientific measurement and observation methods which respond to early stages of anthropogenically induced environmental changes and are capable of responding to a multitude of simultaneously present agents. A series of examples is discussed. Approaches concerning how the statistical evaluation of available sets of environment-related data could reveal unexpected developments are presented.

Biosensing Techniques↗

[Alterations of sleep stage pattern in human beings and hang-over effects under the influence of estazolam/2nd Comm.: Studies on the hang-over effect in psycho-physiological performance (author's transl)].

10 healthy male and female subjects spent 7 nights both with a quiet surrounding and defined noise of subsonic jet fly-overs in a sleep laboratory. During the last 4 nights they were medicated in a double-blind cross-over test design with the benzodiazepine 8-chloro-6-phenyl-4H-s-triazolo (4,3-a)-(1,4)benzodiazepine (estazolam, BAY k 4200) at a dosage of 2 mg and placebo. On each following morning they passed a tracking test and an apparative mental arithmetic calculation test in order to evaluate a potential hangover. Simultaneously heart rate was registered continuously. The results were as follows: About 10 h after medication significant hang-over effects of estazolam in psycho-physiological performance could still be seen. Statistically significant differences between the conditions with estazolam and placebo in the range of 5 to 15% were found. Hang-over is not restricted to tracking and mental performance but can also be seen in slightly lowered heart rate.

Anti-Anxiety Agents↗

[Experimental study on the tracking behaviour with a view to differentiating the effects of an antidepressant in various doses compared to placebo (author's transl)].

In a double-blind cross-over study 15 highly motivated, healthy male subjects (Ss), aged from 23 to 29 years, were given 200 mg and 400 mg p-methoxy-phenoxyaceticacid-diethylaminoethylamide-hydrochloride (mefexamide) and a placebo. On each of the three days the Ss were tested in different tracking devices and the integrated absolute error was measured in the tests of a duration of three hours each. Influences of practice, leading to unwanted and disturbing effects were excluded by a preceding period of four training sessions on different days. The main result of the investigation was that performance in tracking was ambivalent. The single dosage (200 mg mefexamide) caused small improvements in tracking in the range of about 5%. These differences from placebo partly could be determined to be significant at the level of 5% compared to placebo. The double dosage (400 mg mefexamide) deteriorated tracking performance significantly (5%-and partly 1%-level, two-tailed test) in the range of about 10% on the average. Differences in performance between the two dosages were correspondingly larger and could be determined at a higher level of significance, too.

Adult↗