US4289969A
Expired / Lapsed
US
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Radiation imaging apparatus
Assignee: SCAN TECH Inc A CORP OF MA
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Filing: 1978-07-10
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Granted: 1981-09-15
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Expires: 1998-07-10
Abstract
Abstract Radiation imaging apparatus especially suited for use in a computerized tomographic (CT) scanner employs an array of discrete X-ray sources, each being a cold cathode diode and an adjacent fixed array of closely packed radiation detectors to produce images of rapidly moving body organs such as the beating heart. A variety of alternative X-ray source embodiments are also disclosed.
Inventors
- 👤 Gerald Cooperstein
- 👤 Richard C. Lanza
- 👤 A. Robert Sohval
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:51
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/42; A61B6/4275; A61B6/02; A61B6/03; A61B6/032; A61B6/40; A61B6/4007; H; H01; H01J; H01J35/00; H01J35/02; H01J35/04; H01J35/22; H05; H05G; H05G1/00; H05G1/08; H05G1/10; H05G1/20; H05G1/70
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
115 words
In a computerized tomographic scanner: A. a fixed array of cold cathode diodes each said diode being characterized by an impedance in excess of about 100 ohms; B. a fixed array of radiation detectors juxtaposed to the diode array; C. means for applying greater than 100 ns duration and less than 200 kv voltage pulses sequentially to the diodes in the array so as to cause said diodes to emit successive substantially constant amplitude X-ray pulses, said radiation being detected by the detectors in the detector array, and D. means responsive to the output signals from said detectors for producing a reconstruction image of a selected body slice illuminated by radiation from the diode array.
Claim 2
Dependent Claim
115 words
In a computerized tomographic scanner: A. a fixed array of cold cathode diodes each said diode being characterized by an impedance in excess of about 100 ohms; B. a fixed array of radiation detectors juxtaposed to the diode array; C. means for applying greater than 100 ns duration and less than 200 kv voltage pulses sequentially to the diodes in the array so as to cause said diodes to emit successive substantially constant amplitude X-ray pulses, said radiation being detected by the detectors in the detector array, and D. means responsive to the output signals from said detectors for producing a reconstruction image of a selected body slice illuminated by radiation from the diode array.
Claim 3
Dependent Claim
24 words
The scanner defined in claim 1 wherein the source and detector arrays are circular with a common axis and are positioned adjacent one another.
Claim 4
Dependent Claim
30 words
The scanner defined in claim 2 wherein each diode in the source array is arranged radially with respect to said axis so as to constitute a point source of X-rays.
Claim 5
Dependent Claim
28 words
The scanner defined in claim 2 wherein each diode in the source array is arranged parallel to said axis so as to constitute a line source of X-rays.
Claim 6
Dependent Claim
24 words
The scanner defined in claim 1 wherein each diode comprises: A. a rod-like anode, B. a generally cylindrical cathode arranged concentrically to the anode.
Claim 7
Dependent Claim
25 words
The scanner defined in claim 1 wherein the diodes comprise electrically conductive plates spaced adjacent one another, adjacent pairs of plates constituting a separate diode.
Claim 8
Dependent Claim
28 words
The diode defined in claim 6 and further including one or more electrically conductive field enhancement blades projecting from one plate toward the other in each plate pair.
Claim 9
Dependent Claim
25 words
The scanner defined in claim 5 and further including one or more electrically conductive annular field enhancement blades projecting from the cathode toward the anode.
Claim 10
Dependent Claim
17 words
The scanner defined in claim 5 wherein said cathode and anode are both comprised primarily of carbon.
Claim 11
Dependent Claim
18 words
The scanner defined in claim 9 and further including a thin coating of tungsten metal on said anode.
Claim 12
Dependent Claim
18 words
The scanner defined in claim 10 and further including a thin coating of carbon covering said tungsten coating.
Claim 13
Dependent Claim
13 words
The scanner defined in claim 5 wherein said diode anode comprises tungsten metal.
Claim 14
Dependent Claim
39 words
The scanner defined in claim 1 wherein the diodes in the array comprise A. a pair of spaced-apart cathode plates, and B. a set of anode wires spaced parallel to one another in a common plane between said plates.
Claim 15
Dependent Claim
36 words
The scanner defined in claim 13 and further including one or more field enhancement blades projecting from said cathode plate toward said wires, said cathode plates being oriented more or less perpendicular to said anode wires.
Claim 16
Dependent Claim
17 words
The scanner defined in claim 5 wherein a lengthwise end segment of said anode is inwardly tapered.
Claim 17
Dependent Claim
41 words
The scanner defined in claim 1 and further including means for pre-pulsing each diode prior to the application of said pulse to said diode with one or more no greater duration pulses to drive off desorbed gases from said diode anode.
Claim 18
Dependent Claim
33 words
The scanner defined in claim 1 wherein each said low voltage pulse is on the order of 120 to 130 KV. and has a duration on the order of 150 to 160 ns.
Claim 19
Dependent Claim
27 words
The scanner defined in claim 1 wherein each said diode has an initial impedance in excess of 2.8 times the output impedance of said pulse applying means.
Claim 20
Dependent Claim
28 words
The scanner defined in claim 18 wherein each said diode has an initial impedance that is 4 to 5 times the output impedance of the pulse applying means.
References Cited (Backward Citations)
US4129783A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-14 | 1985-03-16 | 1985-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-14 | 1989-03-16 | 1989-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-14 | 1993-03-16 | 1993-09-15 | $7700.00 | Window Closed / Lapsed |