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Biomedical subjects

P W Walton

Publications and source records attributed to P W Walton.

10 recordsLinked to original sources
PubMed1977

A simple isodose plotter using a rectilinear radioisotope scanner.

An inexpensive isodose plotter is described which uses major items already present in most radiology departments. A rectilinear scanner provides scanning motions and plotting table and two electrometers are used to measure the currents from silicon diodes used as reference adn probe detectors. A simple box of electronics, incorporating an integrated ratio circuit and 13 integrated circuit comparators, interfaces the electrometers to the scanner's printing mechanism. The device worked very satisfactorily and took between 30 and 60 minutes for each plot.

Humans↗
PubMedDate not supplied

Dynamic nuclear-medicine image display system using standard multiformatter images.

There is much interest in visualizing dynamic physiological function using nuclear-medicine techniques. In particular, these methods are used in cardiac studies, but it is likely that many other functions will be better visualized with cinematographic-type displays. A new instrument is described which takes a sequence of images, records on a single sheet of film by standard formatting devices and, by means of digitally controlled mirrors, projects them in rapid sequence onto a screen to produce the dynamic movie display.

Analog-Digital Conversion↗
PubMedDate not supplied

Evaluation of optically projected x-ray images from an elastomer-based ionographic system.

In ionographic imaging, the ions produced in a high-pressure, high-Z gas are normally collected on an insulating foil. If a deformable dielectric gel is used as a collecting electrode, then the electrostatic image can be visualized by optically projecting the gel deformation onto a screen. In the present work, we have evaluated the imaging performance of such an ionographic system in terms of its sensitivity and resolution capabilities. X-ray images of a sharp lead edge formed on a thin silicone elastomer were optically projected and recorded on x-ray films. The edge profiles were obtained at different values of x-ray exposure, elastomer thickness, gas pressure, and collecting voltage across the chamber. These profiles were processed to obtain the sensitivity and resolution of the system at different operating conditions. Images of some test objects are shown using this system in order to demonstrate its clinical potential.

Chlorofluorocarbons, Methane↗