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Biomedical subjects

W Brockmann

Publications and source records attributed to W Brockmann.

9 recordsLinked to original sources
PubMed2002

[Mobile autonomous robots-Possibilities and limits].

Besides industrial robots, which today are firmly established in production processes, service robots are becoming more and more important. They shall provide services for humans in different areas of their professional and everyday environment including medicine. Most of these service robots are mobile which requires an intelligent autonomous behaviour. After characterising the different kinds of robots the relevant paradigms of intelligent autonomous behaviour for mobile robots are critically discussed in this paper and illustrated by three concrete examples of robots realized in Lübeck. In addition a short survey of actual kinds of surgical robots as well as an outlook to future developments is given.

Artificial Intelligence↗
PubMed2001

Quantum mechanical quantitative structure activity relationships to avoid mutagenicity in dental monomers.

The objective of this study was to identify through quantum mechanical quantitative structure activity relationships (Q-QSARs) chemical structures in dental monomers that influence their mutagenicity. AMPAC, a semiempirical computer program that provides quantum mechanical information for chemical structures, was applied to three series of reference chemicals: a set of methacrylates, a set of aromatic and a set of aliphatic epoxy compounds. QSAR models were developed using this chemical information together with mutagenicity data (Salmonella TA 100, Ames Test). CODESSA, a QSAR program that calculates quantum chemical descriptors from information generated by AMPAC and statistically matches these descriptors with observed biological properties was used. QSARs were developed which had r2 values exceeding 0.90 for each study series. These QSARs were used to accurately predict the mutagenicity of BISGMA. a monomer commonly used in dentistry, and two epoxy monomers with developing use in dentistry, GY-281 and UVR-6105. The Q-QSAR quantum mechanical descriptors correctly predicted the level of mutagenicity for all three compounds. The descriptors in the correlation equation pointed to components of structure that may contribute to mutagenesis. The QSARs also provided 'dose windows' for testing mutagenicity, circumventing the need for extensive dose exploration in the laboratory. The Q-QSAR method promises an approach for biomaterials scientists to predict and avoid mutagenicity from the chemicals used in new biomaterial designs.

Dental Enamel↗
PubMed1993

[The layers of the gallbladder wall: an ultrasound-anatomic comparative study].

In a sonographic-histological comparative test, operatively withdrawn gallbladders in native and formol-fixed states were examined. The thickness of the gallbladder wall and of its layers was measured sonographically. Afterwards the gallbladders were reexamined microscopically in the sonographic sectional plane and the measurement was repeated. By removal of the single layers of the wall and by repeated sonographic measuring, sonographic and microscopic measurements of the parietal layers could be correlated. Both gallbladder wall thickness and thickness of the single anatomic layers can be evaluated sonographically. The correlation between sonographic and histological measurements is fairly to highly significant. The sonographically measurable layers can be related to the following anatomical layers (when measuring from outwards to inwards): 1. echogenic layer = initial echo and subserosa; 2. echo-poor layer = muscularis; 3. echogenic layer = lamina propria; 4. echo-poor layer = mucosal epithelium; 5. echogenic layer = exit echo.

Cholecystectomy↗
PubMed1991

Tumors of the urinary bladder in painters: a case-control study.

In a case-control study, 403 male patients with a diagnosis of "bladder tumor" and (as controls) 426 patients suffering from prostate disease were investigated. The results of this study indicate that past employment as a painter was associated with an excess risk of bladder tumor. The relative risk of bladder tumor estimated for painters was 2.76. The possible role of benzidine-based azodyes (or azodyes based on substituted benzidines) as a carcinogenic risk factor for painters is discussed.

Adult↗
PubMed1988

Comparison of two analytical procedures for the determination of free urinary catecholamines under the demands of shiftwork experiments.

A typical shiftwork experiment was chosen to prove the validity of an automated procedure for the analysis of free noradrenaline and adrenaline in urine. The method consists of a column switching technique with an adsorption/elution clean-up and a reversed phase high performance liquid chromatography followed by chemical reaction detection based on the trihydroxyindole method. The analysis of variance was performed using a second data set obtained by a semi-automated procedure for which the accuracy had already been confirmed. The analysis of covariance showed that for field studies, as well as for laboratory experiments in which the variances contributed by the experiments themselves are greater than 10% rel., the data sets of the two methods provide the same information.

Autoanalysis↗
PubMed1986

Algorithms for the computerised construction of shift systems which meet ergonomic criteria.

A search algorithm is presented to generate all shift systems according to a given set of constraints, including physiological and social requirements. The generated shift systems are weighted according to such criteria as the time distribution of the shifts, the length of the weekend leisure time and the regularity of the shift system. The use of this algorithm is restricted to the construction of shift systems for a maximum of five crews, as is usual in industry. A heuristic algorithm for the construction of more complex shift systems, as used in the services sector, is also described. The user of the program may consider all criteria simultaneously. He must assign priorities to the criteria according to his wishes.

Journal Article↗
PubMed1984

Influence of coffee on the excretion of noradrenaline and adrenaline in urine. A pilot study for the comparison of two methodical models.

In field studies, the excretion rate of urinary catecholamines is very often used as an indicator of strain. Interfering effects which are due to caffeine, for example, can only be quantified if the influence of coffee consumption on the excretion of catecholamines is known quantitatively. This was the aim of our study with five subjects, on five consecutive working days, and with a strict standardization of nutrition. The urine samples were specified with respect to the following parameters: sampling period, volume, urine status, density, creatinine, noradrenaline, and adrenaline. Adrenaline showed a significant correlation with coffee consumption, whereas noradrenaline did not. Moreover, it could be demonstrated that relating the concentration of catecholamines to the creatinine excretion is insufficient for work physiology studies, especially if the urine sampling periods are as short as 2h.

Adult↗
PubMed1980

[Occupational health studies on airport transport workers. I. Results of ergonomic time and motion studies (author's transl)].

Loading and unloading of aircrafts involves lifting, moving, and carrying of heavy cargo in unfavourable body positions and in narrow spaces. This transport work was subjected to an investigation in a big airport. Forty-three male transport workers and foremen were studied during 46 total shifts. The type of activity was recorded by using the standardized procedure, the so-called "Arbeitswissenschaftliches Erhebungsverfahren zur Tätigkeitsanalyse" (AET). For time and motion analysis, body positions were recorded by continuous observation during the total shift. For typical activities the energy expenditure was determined. The strain caused by transport work was estimated by recording the heart rate with a portable cardiocorder during the total shift. The results show that both dynamic and static work are involved in the loading and unloading of aircrafts. The heart rate varied characteristically according to the body position and to type of activity. The body position was mainly determined by the height of the bellies (from 0.61-1.97 m) of different aircrafts. An additional influence due to weight carrying could be observed only in body positions with low energy expenditure. Recommendations for changing the height of the bellies or to the appropriate selection of workers were made.

Adult↗