US4568828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rapid determination of linearity in a dose calibrator
Assignee: Individual
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Filing: 1981-04-20
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Granted: 1986-02-04
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Expires: 2001-04-20
Abstract
Abstract A method of testing dose calibrator linearity comprising the steps of serially interposing a plurality of shields between the sample and detector, each shield having a given thickness to absorb a desired fraction of the radiation; measuring the activity of the sample as attenuated by the shields; calculating the actual activity of the sample at each level of attenuation; and comparing the measured activities with the calculated activities. For carrying out the method several embodiments of shields are described.
Inventors
- 👤 Carl J. Collica
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:08
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
87 words
A test method for evaluating response of a dose calibrator for measuring the amount of radiation produced by a radioactive source subject to decay, said method comprising the steps of: (a) disposing the source for continuous measurement by the dose calibrator during the test; (b) simulating different amounts of source decay by successively differingly and incompletely shielding the source during a single test; (c) monitoring the response of the dose calibrator to the shielded source at each of the differing shieldings, and (d) comparing said monitored responses.
Claim 2
Dependent Claim
87 words
A test method for evaluating response of a dose calibrator for measuring the amount of radiation produced by a radioactive source subject to decay, said method comprising the steps of: (a) disposing the source for continuous measurement by the dose calibrator during the test; (b) simulating different amounts of source decay by successively differingly and incompletely shielding the source during a single test; (c) monitoring the response of the dose calibrator to the shielded source at each of the differing shieldings, and (d) comparing said monitored responses.
Claim 3
Dependent Claim
112 words
A test process of evaluating uniformity over time of response linearity of a radioisotope dose calibrator, said process comprising the steps of: (a) testing the dose calibrator to assure that its degree of linearity of response is initially within a predetermined standard; (b) placing a quantity of isotope in the dose calibrator for measurement; (c) shielding the radioisotope in a succession of different and incomplete degrees during a single test procedure; (d) measuring and recording the response of the dose calibrator during each of said successive shielding steps; (e) later repeating steps (c) and (d), and (f) comparing the two steps of measurements derived from the performance of steps (d) and (e).
Claim 4
Dependent Claim
112 words
A test process of evaluating uniformity over time of response linearity of a radioisotope dose calibrator, said process comprising the steps of: (a) testing the dose calibrator to assure that its degree of linearity of response is initially within a predetermined standard; (b) placing a quantity of isotope in the dose calibrator for measurement; (c) shielding the radioisotope in a succession of different and incomplete degrees during a single test procedure; (d) measuring and recording the response of the dose calibrator during each of said successive shielding steps; (e) later repeating steps (c) and (d), and (f) comparing the two steps of measurements derived from the performance of steps (d) and (e).
Claim 5
Dependent Claim
81 words
A test method for evaluating the response linearity of a radiopharmaceutical dose calibrator, said method comprising the steps of: (a) placing a reference dose in the calibrator; (b) successively shielding the reference dose to different known and incomplete degrees during a single test procedure; (c) recording a calibrator measurement reading for each degree of shielding; (d) multiplying each reading by a factor which is a function of the degree of shielding corresponding to that reading, and (e) comparing the resulting products.
Claim 6
Dependent Claim
81 words
A test method for evaluating the response linearity of a radiopharmaceutical dose calibrator, said method comprising the steps of: (a) placing a reference dose in the calibrator; (b) successively shielding the reference dose to different known and incomplete degrees during a single test procedure; (c) recording a calibrator measurement reading for each degree of shielding; (d) multiplying each reading by a factor which is a function of the degree of shielding corresponding to that reading, and (e) comparing the resulting products.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-02-03 | 1989-08-05 | 1990-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-03 | 1993-08-05 | 1994-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-03 | 1997-08-05 | 1998-02-04 | $7700.00 | Window Closed / Lapsed |