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Biomedical subjects

J L Cambier

Publications and source records attributed to J L Cambier.

10 recordsLinked to original sources
PubMed1988

An EPROM-based programmable contour generator for use in flow cytometry.

An erasable programmable read-only memory (EPROM) contour generator has been fabricated to produce contours for use in flow cytometry. Contours are analog waveforms representing the fluorescence or light-scatter intensity distribution along a cell or object. The generator has particular utility in the development and testing of slit-scan instrumentation and analysis algorithms. Contours are generated without the requirement of specimens or full operation of the flow instrumentation. The generator provides control of contour height, width, offset, and rate. The EPROM may be custom programmed to produce contours for specific test applications or for reproducing "real" contour events. The generator is useful in situations where constant repetitive contours of predetermined characteristics are required.

Electronic Data Processing↗
PubMed1979

A multidimensional slit-scan flow system.

A new slit-scan type flow system is described which provides three (X, Y, and Z) orthogonal one-dimensional projections of cell fluorescence. A photomultiplier tube and two semiconductor array detectors are used to obtain the three slit-scan contours from cells traversing a single fluorescence excitation beam. A high speed, dedicated preprocessor analyzes the three contours in parallel, extracting certain features useful for rejecting cells from which an accurate measurement of nuclear fluorescence cannot be obtain. Contour data is buffered and transferred to a PDP-11/40 computer where nuclear fluorescence is measured and cells are classified. It is anticipated that this new instrument will provide a significant reduction in false alarm rate when applied to prescreening of gynecologic cytology specimens.

Computers↗
PubMed1979

Predicted performance of single- versus multiple-slit flow systems.

Flow systems utilizing multiple orthogonal excitation slits have been proposed as a means of reducing some types of false alarms in prescreening systems for gynecologic cytology. Such false alarms include those caused by orientation-dependent events, such as passage of binucleate or overlapping cells through the measurement region with both nuclei entering the excitation slit simultaneously. This paper presents distributions of optimal projection angles for randomly oriented nuclei passing through one, two, and three slit excitation regions. The results are used to compute observed nuclear spacing of binucleate cells and to compare performance of one, two, and three slit systems in recognition of binucleate and overlapping cells.

Cell Nucleus↗
PubMed1979

Imaging in flow.

Imaging in flow has been valuable in investigating discrepancies in flow cell measurements due to cell orientation and flow dynamics. This paper discusses optical consideration in flow imaging, slit and full field imaging systems and various cell motion arresting techniques from the standpoint of image plane exposure and suitable detector choices. It concludes with an explanation of the slit-imaging techniques employed in a multidimensional slit-scan flow system and slit-scan correlation system.

Cell Nucleus↗
PubMed1979

False alarms in a slit-scan flow system: causes and occurrence rates. Implications and potential solutions.

A slit-scan technique was developed as a basis for an automated prescreening system for gynecologic cytology. A flow system based on this technique was fabricated and tested and results indicated that false alarms (misclassification of objects or events from normal specimens as abnormal) are the greatest remaining obstacle to development of an automated prescreening instrument. A dual view correlation system was fabricated to provide exact image-contour correlation in flow and permit precise determination of causes and occurrence rates of false alarms. This paper presents data from correlation analyses of 23 normal cytologic specimens. Major causes of false alarms and their implications to automated prescreening are discussed. A technique that would eliminate the majority of false alarms in flow is presented.

Cervix Uteri↗
PubMed1977

Imaging systems for correlation of false alarms in flow.

False alarms, arising from a variety of sources, are the greatest remaining obstacle to development of an automated prescreening system for gynecologic cytology. This paper describes two correlation systems under development at the University of Rochester and discusses their utilization in the study of false alarms in slit-scan cytofluorometry. Both systems permit imaging of objects in flow and correlation between images and corresponding slit-scan contours. Correlation systems will permit a detailed study of false alarm causes and aid in the search for new features to assist in their recognition.

Autoanalysis↗
PubMedDate not supplied

The binucleate cell: implications for automated cytopathology.

A study of occurrence rates of binucleate cells in human femal gynecological specimens is described. Data is presented on probability of occurrence, nuclear spacing, and nuclear fluorescence of binucleate cells. Allowable binucleate recognition error rates for automated cytopathology are presented. Recognition techniques employing slit-scan cytofluorometry are discussed.

Cell Count↗
PubMedDate not supplied

Binucleate cell recognition in automated gynecologic cytopathology.

Medium resolution two dimensional image analysis techniques were applied to a large number of abnormal and binucleate cells from the uterine cervix. Techniques were developed for the extraction of nuclear boundary information from fluorescence images and two new nuclear shape descriptors were applied to the binucleate cell recognition problem. The descriptors were a contextual measure of concavity location and size on the nuclear boundary, and mean area of the two largest concavities. These features were superior both to total convex deficiency and to ratio of perimeter squared to area when applied to binucleate cell recognition. Classification based on the second feature, mean convex deficiency, provided lowest error rates. These were approximately 10% false positive and false negative single cells, and occurred with an effective two micron spot size. Higher false negative rates were observed with a one micron spot size.

Autoanalysis↗