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Biomedical subjects

B Trus

Publications and source records attributed to B Trus.

8 recordsLinked to original sources
PubMed1995

Quantitative analysis of retroillumination images.

We have developed a semi-automated image processing system for analysis and evaluation of retroillumination images. This paper describes methods used to compensate for illumination variations in the images, separation of data into cataractous and non-cataractous portions, how quantitative measurements are made and how they assess the pathological condition. In addition to the traditional area measurement, this system computes the net integral of density and several measurements involving the location of the opacity in relation to the pupillary margin. The computer measures of area, integral of density, area centrality, weighted area, density centrality and weighted density provide more data than previously described systems. Data produced by this interactive and automated system can be used in studies of posterior subcapsular and cortical cataracts, and to study the effect of these opacities on vision.

Cataract↗
PubMed1993

Development of a Scheimpflug slit lamp camera system for quantitative densitometric analysis.

We have developed a computerised video system for accurate quantification of lens opacities from Scheimpflug images. Using a modified Zeiss Scheimpflug camera and Macintosh computer, the system software can warn of improper exposure and can provide immediate results of cataract progression on individual patients. These results are obtained from a novel technique which automatically divides the lens into anatomical regions and computes regional densities in the standard optical density unit. Because of the system's speed, the operator can properly capture and analyse a cataract in seconds, compare results with past patient records and give feedback to the patient on the results of the analysis. The system provides the appropriate data integrity and formats for documenting and monitoring lens opacities. Such a system will be useful in longitudinal studies of cataracts (i.e. for natural history and anti-cataract drug trials).

Cataract↗
PubMed1991

Computerized methods for analyzing two-dimensional agarose gel electropherograms.

Previous methods interpret zonal or polydisperse gel patterns of two-dimensional Serwer-type gels in terms of size and free mobility (surface net charge density). These two parameters have been determined for each component without quantitatively measuring the abundance of the components. The present study advances these previous methods by determining the relative concentration of each component by computer evaluation of densitometrically analyzed gel patterns. Suitable procedures and their underlying algorithms are presented. The mathematical routines are implemented in a user-friendly software package, called GelFit and designed for a Macintosh personal computer. The program input consists of digitized images of gel staining patterns exemplified by those obtained from electrophoresis of native subcellular-sized particles. The data are processed through the following steps: (i) Noise reduction and calibration. (ii) Geometrical transformation of the pattern onto a rectangular size/free mobility coordinate system using rationales of the extended Ogston model. (iii) Analysis of the transformed image to determine density maxima, density profiles along iso-free-mobility or iso-size lines, curve fitting of one-dimensional profiles or two-dimensional surfaces using Gaussian functions and curve stripping of surfaces to determine the possible number of particle populations.

Algorithms↗