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Biomedical subjects

H G Adelmann

Publications and source records attributed to H G Adelmann.

4 recordsLinked to original sources
PubMed1999

Design of a PC-based system for time-domain and spectral analysis of heart rate variability.

Investigation of heart rate variability is the subject of considerable interest in physiology, clinical medicine, and clinical pharmacology. The functional assessment of the autonomic nerve system by observation of its main actors, the sympathetic and parasympathetic branch, is emphasizing the importance of autonomic regulation under different physiological circumstances, in several disease states, and under drug therapy. This paper describes a PC-based system designed with LabView that performs time-domain and frequency-domain analyses of heart rate variability as suggested by the guidelines of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Examples for heart rate variability are given for different physiological states along with an analysis and evaluation by the system described.

Algorithms↗
PubMed1999

The effect of ketoconazole on the pharmacokinetics, pharmacodynamics and safety of nisoldipine.

OBJECTIVE: The primary aim of the present study was to investigate the effect of ketoconazole on the pharmacokinetics of nisoldipine. METHODS: A single dose of nisoldipine 5 mg immediate-release tablet was administered either alone or in combination with ketoconazole 200 mg (4 days pretreatment and concomitant administration) in a randomized crossover trial in seven healthy male Caucasian volunteers. Plasma concentration-versus-time profiles of nisoldipine and its metabolite M9 were determined. RESULTS: Pre-treatment with and concomitant administration of ketoconazole resulted in a 24-fold and 11-fold, increase in mean AUC and Cmax of nisoldipine, respectively, compared with treatment with nisoldipine 5 mg alone. The ketoconazole-induced increase in plasma concentration of the metabolite M9 was of similar magnitude. CONCLUSION: The interaction is attributed to inhibition of cytochrome 3A4-mediated first-pass metabolism. Ketoconazole and other antifungal drugs of the substituted imidazole type as well as other potent inhibitors of cytochrome 3A4 should not be used concomitantly with nisoldipine.

Adult↗
PubMed1998

Butterworth equations for homomorphic filtering of images.

In digital image processing, the homomorphic filtering approach is derived from an illumination-reflectance model of the image. Homomorphic filtering can perform simultaneous dynamic range compression and contrast enhancement. Crucial for the success of the homomorphic approach is the selection of an appropriate frequency-domain filter function in order to modify the illumination and reflectance components of an image differently. The author found Butterworth type highpass equations far superior to other frequency-domain filter functions, including Gaussian equations, making the Butterworth highpass suitable for use with the homomorphic filtering approach. The program was written in Microsoft (MS) Visual C++ (filter) as well as MS Visual Basic (user interface) to run as a module under the image processing software package Image-Pro Plus.

Blood Cells↗