IP Library Granted Patent US 7,405,412
Granted Patent B2
US 7,405,412 · App. 11/408,234 · Granted Jul 29, 2008

Method for calibrating a radiation detection medium

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Quick Facts
Patent No.
US 7,405,412
App. No.
11/408,234
Granted
Jul 29, 2008
Kind
B2
Abstract

A method for calibrating a radiation detection medium by exposing arbitrary locations of a radiation detection medium to a plurality of known radiation dose levels is described. One particular aspect of the method includes the steps of automatically determining the location of each arbitrary exposed location, measuring the density of each of the arbitrary exposed locations, matching each measurement for the arbitrary exposed locations with the corresponding radiation dose level thereby generating an array of paired data values for radiation dose level and measured density and calculating a calibration based on the array of paired data values.

Claims (26)

1. A method for calibrating a radiation detection medium comprising:

exposing arbitrary areas of a radiation detection medium to a plurality of known radiation dose levels wherein each exposed arbitrary area is in a location and corresponds to a known radiation dose level,

scanning the exposed detection medium and automatically determining the location for each exposed arbitrary area,

measuring each of the exposed arbitrary areas,

matching each measurement for the exposed arbitrary areas with the corresponding radiation dose level, thereby generating an array of paired data values for radiation dose level and measured exposure, and

calculating a calibration based on the array of paired data values.

2. The method of claim 1 wherein the exposed arbitrary areas containing the plurality of known dose levels form a spatial pattern of doses.

3. The method of claim 2 wherein the spatial pattern of dose levels is comprised of a plurality of discrete areas within each of which the dose level is substantially uniform.

4. The method of claim 3 , wherein said plurality of known radiation dose levels comprises from about 3 to about 25 different dose levels.

5. The method of claim 3 , wherein said known radiation dose levels fall within the range of from about 1 cGy to about 1000 cGy.

6. The method of claim 3 , wherein the step of automatically determining a location for each exposed arbitrary area comprises identifying areas of a specified dimension with a uniformity of plus or minus 10%.

7. The method of claim 6 , wherein said uniformity is plus or minus 5%.

8. The method of claim 2 wherein the spatial pattern of dose levels is a pattern of continuously varying dose levels.

9. The method of claim 1 , wherein said radiation-sensitive medium is a radiochromic self-developing film.

10. The radiation-sensitive medium of claim 9 , wherein said radiochromic self-developing film includes a substantially crystalline image receptive polyacetylenic compound having the structure:

A-(CH 2 ) n —C═C—C═C—(CH 2 ) m —B

wherein m and n are both independently an integer from 6 to 14 and A and B are independent from one another and are selected from the group consisting of methyl, carboxyl, hydroxy, amido, lower alkyl substituted amido, aliphatic or aromatic carboxylate ester group having up to 10 carbon atoms, mono- or di-valent carboxylate metal salt group, halo, carbamyl, lower alkyl substituted carbamyl or tosyl, triyn or tetrayne products of the above polyacetylenes having from 20 to 60 carbon atoms and a conjugated structure, and combinations thereof.

11. A method for calibrating a radiation detection medium comprising:

irradiating a radiation detection medium with at least three different radiation dose levels, each dose level being applied to an arbitrary area on the detection medium to produce an exposed detection medium comprising random irradiated areas,

capturing an image of the exposed detection medium to form a scanned image,

analyzing the scanned image to detect each of the irradiated areas on the detection medium,

determining the dose level corresponding to each irradiated area, and

calculating a calibration for the detection medium based on density as a function of dose level.

12. The method of claim 11 , wherein the step of analyzing the scanned image to detect each of the irradiated areas on the detection medium comprises measuring density of each of the irradiated areas.

13. The method of claim 12 , wherein the irradiated areas are selected based on predetermined criteria for image size and uniformity.

14. The method of claim 11 , wherein said radiation sensitive medium is a radiochromic self-developing film.

Assignments (7)
RELEASE OF SECURITY INTEREST Recorded Jan 10, 2020
From: THE BANK OF NOVA SCOTIA
To: AVOCA LLC; HERCULES LLC; ISP INVESTMENTS LLC; PHARMACHEM LABORATORIES LLC
Reel/Frame 051557/0504 →
SECURITY AGREEMENT Recorded Jul 3, 2017
From: AVOCA, INC.; HERCULES LLC; ISP INVESTMENTS LLC; PHARMACHEM LABORATORIES, INC.
To: THE BANK OF NOVA SCOTIA, AS ADMINISTRATIVE AGENT
Reel/Frame 043084/0753 →
CONVERSION Recorded Jan 30, 2017
From: ISP INVESTMENTS INC.
To: ISP INVESTMENTS LLC
Reel/Frame 041556/0499 →
RELEASE OF PATENT SECURITY AGREEMENT Recorded Mar 18, 2013
From: THE BANK OF NOVA SCOTIA
To: ASHLAND LICENSING AND INTELLECTUAL PROPERTY LLC; AQUALON COMPANY; ISP INVESTMENTS INC.; HERCULES INCORPORATED
Reel/Frame 030025/0320 →
PATENT RELEASE Recorded Sep 19, 2011
From: JPMORGAN CHASE BANK, N.A. (F/K/A THE CHASE MANHATTAN BANK)
To: ISP CAPITAL, INC.; ISP CHEMICAL PRODUCTS, INC.; VERONA, INC.
Reel/Frame 026930/0774 →
SECURITY AGREEMENT Recorded Sep 16, 2011
From: ASHLAND LICENSING AND INTELLECTUAL PROPERTY LLC; HERCULES INCORPORATED; AQUALON COMPANY; ISP INVESTMENT INC.
To: THE BANK OF NOVA SCOTIA, AS ADMINISTRATIVE AGENT
Reel/Frame 026918/0052 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 20, 2006
From: LEWIS, DAVID F.
To: ISP INVESTMENTS INC.
Reel/Frame 017787/0666 →