Isp Investments Inc.

J Michael Donahue

David F Lewis

Carl A Listl

Henry Seiwatz

Moshe Gershenson

Sotiri A Papoulias

John Dragasevich

In a method for manufacturing a calibrated radiation dosimeter, a layer of radiation sensitive material is applied to a substrate, the radiation sensitive material having an optical density which varies in accordance with a degree of radiation exposure. A pre-exposure optical density of the layer of radiation sensitive material is optically measured and subsequently the layer of radiation sensitive material is exposed to a known dose of radiation. Thereafter, a post-exposure optical density of the layer of radiation sensitive material is optically measured. Using at least the pre-exposure optical density, the post-exposure optical density, and the known dose of radiation, one computes mathematical parameters defining a predetermined mathematical function. The computed mathematical parameters are applied in encoded form to the substrate (e.g., printed in bar code form on the substrate or a holder card).

Method for manufacturing calibrated radiation dosimeter

A method for determining a level of exposure to radiation utilizes a radiation dosimeter comprising a substrate provided with a radiation sensitive layer or patch having an optical density which varies in accordance with the degree of radiation exposure. In addition, the substrate is provided with optically readable coding which identifies one or more encoded mathematical parameters for enabling an automated calculation of dosage from a detected optical density change of the radiation sensitive material. In the method, the coding on the dosimeter substrate is scanned to automatically determine the encoded mathematical parameters, and a plurality of pre-exposure optical densities and a plurality of post-exposure optical densities of the layer of radiation sensitive material in a plurality of wavelength bands are optically measured. From these quantities, a quantitative radiation dose to which the layer of radiation sensitive material was exposed is automatically computed in accordance with a predetermined mathematical algorithm. Each dosimeter is provided with a unique identification code encoded in the bar coding on the dosimeter substrate, to enable memory storage of pre-exposure optical densities for multiple dosimeters.

Radiation dosimetry method and apparatus

A method for determining a level of exposure to radiation utilizes a radiation dosimeter comprising a substrate provided with a radiation sensitive layer or patch having an optical density which varies in accordance with the degree of radiation exposure. In addition, the substrate is provided with optically readable coding which identifies encoded mathematical parameters for enabling an automated calculation of dosage from a detected post-exposure optical density of the radiation sensitive material. The method comprises the step of optically measuring the optical density of the layer of radiation sensitive material prior to exposure thereof to radiation. In addition, the coding on the dosimeter substrate is scanned to automatically determine the encoded mathematical parameters. The method further comprises the steps of exposing the radiation sensitive layer to radiation and optically measuring a post-exposure optical density of the layer of radiation sensitive material. Subsequently, from the pre-exposure optical density, the post-exposure optical density, and the mathematical parameters and in accordance with a predetermined mathematical algorithm, a quantitative radiation dose to which the layer of radiation sensitive material was exposed is automatically computed. Preferably, the computed quantitative radiation dose is automatically indicated on a display. Each dosimeter may be provided with a unique identification code encoded in the bar coding on the dosimeter substrate, to enable memory storage of pre-exposure optical densities for multiple dosimeters. A look-up table may be stored in memory for enabling correction of computed optical densities where the post-exposure densities are measured at different times intervals after exposure.

A radiation dosimeter for preparing a dosage map of a specific rotary canister of a blood radiating machine. This dosimeter includes a sandwich assembly of a first panel and a second panel and a gamma ray-sensitive film disposed therebetween, for mounting temporarily in the canister during gamma ray dosage and canister rotation.

Radiation dosimeter

A filter apparatus having a bag filter subassembly for collecting contaminating material. The bag filter subassembly includes a bag filter having a top end portion and an integral collar. The collar has a lower portion fixedly connected to the bag filter, and has a middle portion to be supported within a vessel, and has a top lip portion to engage a cover plate of the vessel. The collar has a pivotal web portion disposed between the middle portion and the top lip portion, and has an inner surface with a groove having sidewalls, whereby internal pressure on the sidewalls pivot the top lip portion causing a sealing ring bearing area on the cover plate.

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Oakland, NJ, United States of America

J Michael Donahue