First person account: schizophrenia.
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Adult↗
Biomedical subjects
R Bayley
Publications and source records attributed to R Bayley.
Radiation dosimetry by automatic image analysis of dicentric chromosomes.
A system for scoring dicentric chromosomes by image analysis comprised fully automatic location of mitotic cells, automatic retrieval, focus and digitization at high resolution, automatic rejection of nuclei and debris and detection and segmentation of chromosome clusters, automatic centromere location, and subsequent rapid interactive visual review of potential dicentric chromosomes to confirm positives and reject false positives. A calibration set of about 15,000 cells was used to establish the quadratic dose response for 60Co gamma-irradiation. The dose-response function parameters were established by a maximum likelihood technique, and confidence limits in the dose response and in the corresponding inverse curve, of estimated dose for observed dicentric frequency, were established by Monte Carlo techniques. The system was validated in a blind trial by analysing a test set comprising a total of about 8000 cells irradiated to 1 of 10 dose levels, and estimating the doses from the observed dicentric frequency. There was a close correspondence between the estimated and true doses. The overall sensitivity of the system in terms of the proportion of the total population of dicentrics present in the cells analysed that were detected by the system was measured to be about 40%. This implies that about 2.5 times more cells must be analysed by machine than by visual analysis. Taking this factor into account, the measured review time and false positive rates imply that analysis by the system of sufficient cells to provide the equivalent of a visual analysis of 500 cells would require about 1 h for operator review.
Cells, Cultured↗
A fast interval processor (FIP) for cervical prescreening.
A cervical prescreening device (FIP: fast interval processor) designed to scan and classify a slide-mounted specimen within two minutes is described. The image analysis techniques are based directly on the MRC Cerviscan equipment with the minimal conversion needed to adapt these techniques for interval processing. A high scanning rate is achieved by scanning with a charge-coupled diode linear image sensor along one axis and by stepping the microscope stage continuously along the other axis. High processing rates are achieved using an asynchronous pipeline approach. Operations on pixels are carried out by parallel dedicated hardware units, while operations on intervals (segments) are carrie out using a dual microprocessing configuration. A determined attempt has been made to minimize the cost of the components required. Preliminary results showing scanning and processing performance are given.
Cervix Uteri↗
A cytogeneticist's microscope.
It is demonstrated that there are a number of advantages in using a mechanised microscope for scoring a large number of metaphase cells from human blood lymphocyte preparations. Following the development of an automatic metaphase spread finding machine based upon a large motorised microscope and a synchronous closed circuit television camera and flashing light source, a much smaller machine which is more appropriate to the cytogenetics laboratory, but with a similar metaphase finding performance has been constructed. The new machine which consists of a Cambridge Instruments 1 micron stepping microscope stage, a linear diode array scanner and a computer is described in detail. Metaphase finding performance figures for various orcein stained human blood lymphocyte preparations are given.
Cytogenetics↗