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Patent US4670657A successfully refreshed from Google Patents.
US4670657A
Expired / Lapsed
US
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Astigmatic collimator
Assignee: Siemens Medical Solutions USA Inc
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Filing: 1985-03-29
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Granted: 1987-06-02
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Expires: 2005-03-29
Abstract
Abstract A collimator collimates radiation so that each beam passes through two focal lines. One of the lines is in a transaxial plane and the other line is in an axial plane. The focal length in the transaxial plane is longer than is the focal length in the axial plane. In the preferred embodiment, the focal lines are perpendicular, whereby an anamorphic collimator is produced. Alternatively, the focal lines are nonparallel, producing an astigmatic collimator.
Inventors
- 👤 Eric G. Hawman
- 👤 Jiang Hsieh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 07:48
CPC Classifications
G; G21; G21K; G21K1/00; G21K1/02; G21K1/025; G01; G01T; G01T1/00; G01T1/29; G01T1/2914; G01T1/2985; A; A61; A61B; A61B6/00; A61B6/02; A61B6/03; A61B6/037
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
3 words
An astigmatic collimator.
Claim 2
Dependent Claim
3 words
An astigmatic collimator.
Claim 3
Dependent Claim
13 words
The collimator of claim 1, wherein the collimator has two directions of focus.
Claim 4
Dependent Claim
11 words
The collimator of claim 2, wherein said directions are mutually perpendicular.
Claim 5
Dependent Claim
58 words
The collimator of claim 3, wherein one of said directions is in an axial plane when the collimator is used in SPECT and another of said directions is in a transaxial plane when the collimator is used in SPECT, and wherein the focal length in said axial plane is shorter than the focal length in said transaxial plane.
Claim 6
Dependent Claim
16 words
The collimator of claim 1, wherein the collimatro is of a type which collimator non-visible radiation.
Claim 7
Dependent Claim
46 words
An astigmatic collimator for use in SPECT cranial examinations, comprising a radiation-absorbing material arranged to have a first focal length in an axial SPECT plane and a second focal length in a transaxial SPECT plane, said first focal length being shorter than said second focal length.
Claim 8
Dependent Claim
46 words
An astigmatic collimator for use in SPECT cranial examinations, comprising a radiation-absorbing material arranged to have a first focal length in an axial SPECT plane and a second focal length in a transaxial SPECT plane, said first focal length being shorter than said second focal length.
Claim 9
Dependent Claim
3 words
An anamorphic collimator.
Claim 10
Dependent Claim
3 words
An anamorphic collimator.
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) | 1990-06-01 | 1990-12-01 | 1991-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-01 | 1994-12-01 | 1995-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-01 | 1998-12-01 | 1999-06-02 | $7700.00 | Window Closed / Lapsed |