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US4344183A
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Measuring tool for computer assisted tomographic scanner
Assignee: PHYSCIS ASSOCIATES Ltd MILWAUKEE COUNTY WISCONSIN A WISCONSIN CORP
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Filing: 1980-04-14
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Granted: 1982-08-10
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Expires: 2000-04-14
Abstract
Abstract A measuring tool (10) for determining the thickness and position of the X-ray beam of a computer is disclosed which allows the information about the X-ray beam to be derived by analysis of a tomographic image taken of the measuring tool. The measuring tool (10) includes a phantom (12) which has formed therein a plurality of receptacles (14) which receive inserts (16). At least two of the inserts (16) each include therein an image creating pattern (20) including a helical pattern (22) and a center indicator (24) so that both thickness and positioning information can be obtained from the computer-generated tomographic image taken of the tool by examining the images created of the helical patterns (22) and center indicators (24) in the inserts (16).
Inventors
- 👤 Donald R. Jacobson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:11
CPC Classifications
G; G21; G21K; G21K1/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
251 words
A measuring tool for determining the thickness and positioning of the X-ray beam of a computer assisted tomographic scanner comprising: a phantom (12) constructed of a material having low attenuation to X-rays and having at least two receptacles (14) formed therein; reference line means (19) on the exterior of the phantom (12) for defining a reference plane extending therethrough; at least two inserts (16) also formed of a material having low attenuation to X-rays and each shaped so as to fit into a one of the receptacles (14) in the phantom (12); an image creating means for measuring the thickness and position of the X-ray beam including at least one image creating pattern (20) formed of a material having high attenuation to X-rays embedded in one of the inserts (16), the image creating pattern (20) including a center indicator (24) positioned in the reference plane and a helical pattern (22) of a preselected pitch so that the thickness and position of the X-ray beam can be measured from a tomographic image taken of the tool; and tilt detection means for detecting any tilt of the reference plane relative to the plane of the X-ray beam, including at least one other image creating pattern (20) in an insert (16), the image creating pattern (20) including a center indicator (24) and a helical pattern (22) so that any tilt in the beam can be detected by comparing the images of the two image creating patterns (20) in a tomographic image of the tool.
Claim 2
Dependent Claim
251 words
A measuring tool for determining the thickness and positioning of the X-ray beam of a computer assisted tomographic scanner comprising: a phantom (12) constructed of a material having low attenuation to X-rays and having at least two receptacles (14) formed therein; reference line means (19) on the exterior of the phantom (12) for defining a reference plane extending therethrough; at least two inserts (16) also formed of a material having low attenuation to X-rays and each shaped so as to fit into a one of the receptacles (14) in the phantom (12); an image creating means for measuring the thickness and position of the X-ray beam including at least one image creating pattern (20) formed of a material having high attenuation to X-rays embedded in one of the inserts (16), the image creating pattern (20) including a center indicator (24) positioned in the reference plane and a helical pattern (22) of a preselected pitch so that the thickness and position of the X-ray beam can be measured from a tomographic image taken of the tool; and tilt detection means for detecting any tilt of the reference plane relative to the plane of the X-ray beam, including at least one other image creating pattern (20) in an insert (16), the image creating pattern (20) including a center indicator (24) and a helical pattern (22) so that any tilt in the beam can be detected by comparing the images of the two image creating patterns (20) in a tomographic image of the tool.
Claim 3
Dependent Claim
24 words
A measuring tool as claims in claim 1 wherein each of the helical patterns (22) is a continuous wire formed into a helical pattern.
Claim 4
Dependent Claim
26 words
A measuring tool as claimed in claim 1 wherein each of the helical patterns (122) is a series of discrete balls positioned in a helical pattern.
Claim 5
Dependent Claim
40 words
A measuring tool as claimed in claim 1 wherein each of the image creating patterns (220) includes two helical patterns (222A, 222B) of different pre-selected pitch so that beam thickness information can be derived over a broad range of values.
Claim 6
Dependent Claim
22 words
A measuring tool as claimed in claim 1 wherein the phantom (12) and the inserts (16) are formed of a thermoplastic material.
Claim 7
Dependent Claim
30 words
A measuring tool as claim in claim 1 wherein the phantom (12) has formed about its periphery a reference band (18) formed of material having a high attenuation to X-rays.
Claim 8
Dependent Claim
18 words
A measuring tool as claimed in claim 1 wherein the image creating pattern (20) is formed of metal.
Claim 9
Dependent Claim
27 words
A measuring tool as claimed in claim 1 wherein the inserts (16) are frusto-conically shaped and the receptacles (14) in the phantom (12) are correspondingly frusto-conically shaped.
Claim 10
Dependent Claim
22 words
A measuring tool as claimed in claim 1 wherein the center indicator (24) is a ball adjacent to the helical pattern (22).
Claim 11
Dependent Claim
205 words
A measuring tool for determining the thickness and positioning of the X-ray beam of a computer assisted tomographic scanner comprising: a phantom (12) constructed of a material having low attenuation to X-rays; reference line means (19) on the exterior of the phantom (12) for defining a reference plane extending therethrough; at least two inserts (16) in the phantom (12); and image creating means for measuring the thickness and position of the X-ray beam including at least one image creating pattern (20) formed of a material having high attenuation to X-rays embedded in one of the inserts (16), the image creating pattern (20) including a center indicator (24) positioned on the reference plane and a helical pattern (22) of a preselected pitch so that the thickness and position of the X-ray beam can be measured from a tomographic image taken of the tool; and tilt detection means for detecting any tilt of the reference plane relative to the X-ray beam including at least one other image creating pattern (20), the two image creating patterns (20) being separated by a sufficient distance so that tilts of the X-ray beam relative to the reference plane can be detected by comparing the images of the two image creating patterns.
Claim 12
Dependent Claim
205 words
A measuring tool for determining the thickness and positioning of the X-ray beam of a computer assisted tomographic scanner comprising: a phantom (12) constructed of a material having low attenuation to X-rays; reference line means (19) on the exterior of the phantom (12) for defining a reference plane extending therethrough; at least two inserts (16) in the phantom (12); and image creating means for measuring the thickness and position of the X-ray beam including at least one image creating pattern (20) formed of a material having high attenuation to X-rays embedded in one of the inserts (16), the image creating pattern (20) including a center indicator (24) positioned on the reference plane and a helical pattern (22) of a preselected pitch so that the thickness and position of the X-ray beam can be measured from a tomographic image taken of the tool; and tilt detection means for detecting any tilt of the reference plane relative to the X-ray beam including at least one other image creating pattern (20), the two image creating patterns (20) being separated by a sufficient distance so that tilts of the X-ray beam relative to the reference plane can be detected by comparing the images of the two image creating patterns.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-08-09 | 1986-02-08 | 1986-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-09 | 1990-02-08 | 1990-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-09 | 1994-02-08 | 1994-08-10 | $7700.00 | Window Closed / Lapsed |