PubMed Health⌕ Search

Biomedical subjects

J H Tucker

Publications and source records attributed to J H Tucker.

13 recordsLinked to original sources
PubMed1992

HOME: highly optimized microscope environment.

The Highly Optimized Microscope Environment (HOME) is a computerized microscope designed to assist pathologists and cytotechnicians in clinical routine tasks. The prototype system consists of a IBM-PC compatible computer and a light microscope in which a built-in high-resolution computer display image is superimposed on the optical image of the specimen. Also, a manually operated encoding stage and objective turret encoder are used to provide continuous monitoring of the stage coordinates and microscope magnification to the computer. This allows any position on a slide to be uniquely defined and makes it possible to measure interactively lengths and areas larger than the size of the microscope field. Software, written in the C language and operating under the MS-DOS/MS-Windows environment, is controlled by means of a mouse-driven cursor moving over menu light-buttons displayed on the microscope image. The HOME microscope workstation is potentially useful in a wide range of applications such as i) tagging information on particular cells and tissue structures that can thus be accurately located and relocated, ii) performing morphometric measurement, differential counting, and stereological assessment of biological specimens, and iii) training and educating laboratory personnel. Finally, HOME will offer in the near future a user-friendly interface for automatic image processing of cells and tissue entities in interactively selected specimen areas.

Animals↗
PubMed1992

Automation in cervical cytology: an overview.

Cancer of the uterine cervix is one of the more common female cancers and a major source of premature female mortality. UK deaths in 1987 exceeded 2000. To reduce these rates, national screening programmes have been introduced using the Papanicolaou method. In screening for cancer, the examination of specimens is an intensive and expensive task. Its high cost has led to a number of attempts to automate the process, either fully or partially. Over the last 30 years, various experimental prescreening systems have been developed for the diagnosis of cytological samples including the use of image processing techniques. This paper presents a historical overview of automation in cervical cytology and the status of current developments for automated cytological diagnosis.

Automation↗
PubMed1991

Analysis of rare high-DNA cell populations in serous effusions using continuous-motion imaging.

The rare high-DNA cell sub-populations in a series of serous effusion specimens were analysed to determine whether such measurements could provide a basis for the improved diagnosis of malignancy. Monolayer specimens stained with gallocyanin chrome-alum were scanned with the CERVIFIP continuous-motion image analyser to locate and measure the highest-DNA cells in the sample. Two types of features were obtained for the detected sub-populations; firstly, 'percentile ploidy' values which characterise the ploidy levels above which specified proportions of the total cells are found; and secondly 'percentage abnormal' values which characterise the proportion of the cells diagnosed as malignant during examination by a cytopathologist. The classification accuracy for one or both of these features was then obtained by comparison with the clinical outcome of each patient. The results gave a classification error of 9/44 (20%) using the 0.01% percentile ploidy alone, 6/44 (14%) using the 75% percentage abnormal feature alone, but only 2/44 (5%) from a box discriminant using both features. It was therefore concluded that the analysis of the high-DNA cell population could be of value in the diagnosis of malignancy in serous effusion specimens.

Adenocarcinoma↗
PubMed1988

Interval-coded texture features for artifact rejection in automated cervical cytology.

In order to improve the separation between abnormal cells and noncellular artifacts in the CERVIFIP automated cervical cytology prescreening system, 22 different object texture features were investigated. The features were all statistical parameters of the pixel density histograms or one-dimensional filtered values of central and border regions of the object images. The features were calculated for 231 images (100 cells and 131 artifacts) detected as Suspect Cells by the current CERVIFIP and were then tested in hierarchical and linear discriminant classifiers. After selecting the two best features for use in a hierarchical classifier, 83% correct classification was achieved. One of these features was specifically designed to remove poorly focused objects. With maximum likelihood discrimination using all 22 features, an overall correct classification rate of 90% was obtained.

Cell Division↗
PubMed1979

An image analysis system for cervical cytology automation using nuclear DNA content.

An experimental computer/image analysis system has been used to investigate cytology automation techniques based on nuclear DNA measurement and morphological artefact rejector tests. The system automatically measures and normalizes the integrated optical density of cell nuclei in specially prepared cervical cytology specimens, and selects any objects with abnormally high values for further analysis. These are then analyzed by morphological and densitometric tests designed to eliminate false positive signals caused by non-nuclear artefacts. The coordinates of the remaining abnormal nuclei are recorded so that they can subsequently be relocated and examined by a cytotechnician. Preliminary results are given showing the measurement accuracy of the system and the performance of the artefact rejection tests.

Cell Nucleus↗
PubMed1979

The preparation of cervical scrape material for automated cytology using gallocyanin chrome-alum stain.

A method is described for preparing cervical scrape specimens for automated analysis on the Cerviscan prescreening system. In order to reduce the cellular clumping found in cervical scrape material, cells are collected in suspension, syringed to disaggregate the cell clumps, and then pipetted onto a glass to give a monolayer of cells. The cells are then stained with gallocyanin chrome-alum to give the required quantitation of nucleic acid content, using a rapid staining procedure. Experimental results are given which show that specimens prepared by this method are more suitable for automated analysis than the conventional Papanicolaou stained preparation.

Cell Separation↗
PubMed1976

Effects of selected water toxicants on the in vitro activity of fish carbonic anhydrase.

Carbonic anhydrase (CA, carbonate hydro-lyase EC 4.2.1.1) from lysed red blood cells of the channel catfish (Ictalurus punctatus) was studied to determine physico-chemical kinetic properties and relative sensitivity to 56 chemicals of significance in water quality research. In general, enzyme activity was strongly reduced by heavy metal inorganic cations; less strongly by organometallic cations, some anions, and certain pesticides; and weakly inhibited by light metal cations and organometallic and organic compounds. Dose--response curves were qualitatively similar in most cases.

Animals↗
PubMed1976

A real time TV to computer image input system using run coding.

Run coding applied to the digitized video signal from a TV scan of cell preparations can effect a substantial reduction in the total amount of data, sufficient to permit a moderate size of store to be loaded within one frame time with a representation of the field adequate for computer analysis. This paper describes the design of a run coding interface between a TV scanner and a computer store which also allows control of scan domain, spatial resolution and density resolution. Results are presented showing its efficiency when dealing with cervical smear preparations.

Autoanalysis↗
PubMed1976

Automation in cervical cancer screening. Part 1: fixed cell scanning systems.

Cytology automation is highly desirable if a mass cancer screening system is to be effective, and has been the subject of widespread research and development effort. Several experimental systems have been developed based on fixed cell scanning or flow techniques, but clinical trials have produced disappointing results. The major problem with these early systems has been that of false positive "abnormal cell" signals caused by cell overlaps and artifacts. Most current research is devoted to the development of better techniques for cell presentation, to the improvement of pattern recognition techniques, and to the exploitation of novel cell parameters in flow systems.

Automation↗
PubMedDate not supplied

Ellipse test for the reduction of false positive signals in automated cytology.

One of the major problems in automated cytology is the elimination of false positive 'abnormal cell' alarms caused by objects such as overlapping cell pairs, leukocyte clusters, etc. The paper describes an algorithm for the separation of images of abnormal cell nuclei and non=nuclear objects in computer image analysis systems for automated cytology. The algorithm involves the measurement of the agreement between the object outline and a computer ellipse of equal area, aspect ratio and orientation. Results obtained with the CERVISCAN experimental computer image analysis system show that the algorithm gives good discrimination between abnormal cell nuclei and typical non-nuclear objects found in cervical scrape specimens prepared specially for automated analysis.

Cell Nucleus↗