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US4150293A Expired / Lapsed US ⏱️ 0.0 years remaining

Tomographic apparatus for producing transverse layer images

Assignee: Siemens AG
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Filing: 1977-03-21
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Granted: 1979-04-17
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Expires: 1997-03-21
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Abstract

Abstract In an illustrated embodiment a plurality of x-ray sources are arranged at equal angles about a rotating frame. Each source and detector arrangement may provide the desired number of measurements such as 240, so that the required angular movement for scanning is reduced by a factor corresponding to the number of sources. In one embodiment with three sources and 240 detectors for each source, the desired number of measured values may be obtained by rotation through 120 degrees instead of 360 degrees. In another illustrative embodiment, the narrow beam from the x-ray source covers about 30 detectors, the beam and detectors being linearly scanned so as to generate about 240 measurements, there being three source-detector arrangements separated by 60 degrees, so that scanning is carried out by rotation through 60 degrees rather than 180 degrees.

Inventors

  • 👤 Kurt Franke

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 19:48
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/02; A61B6/03; A61B6/032; A61B6/06; A61B6/40; A61B6/4007; A61B6/4014

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 315 words
A tomographic apparatus for producing transversal layer images of a subject, consisting of an x-ray measuring arrangement with a transmitting arrangement for emitting x-rays and with radiation receivers which determine the intensity of radiation behind the subject by scanning the x-rays, and of a drive system for the measuring arrangement with a rotating frame for producing rotational movements of the x-ray measuring arrangement, the transmitting arrangement comprising a plurality of x-ray tubes with their focuses lying substantially on a common circle, and arranged offset at predetermined angles relative to one another, one ray receiver being provided for each x-ray tube, the x-ray tubes being fixedly mounted on the rotating frame and having pinhole diaphragms for condensing the x-ray beam in such a way that it impinges on the ray receivers, said diaphragms being mounted for movement parallel to a tangent of the circle of rotation of the x-ray tubes and the radiation receivers being mounted for movement parallel to the path of the diaphragm such that the x-ray beam always strikes the ray receivers during movement thereof in the scanning of the subject, the ray receivers each consisting of a row of detectors movable as a group parallel to a tangent of the circle of rotation of the x-ray tubes, all of the detectors of each row being simultaneously impinged by the respective x-ray beam in each position of the respective diaphragm during each cycle of tangential movement of the diaphragms, and the rows of detectors all moving tangentially synchronously with the movement of the respective pinhole diaphragms during each cycle of tangential movement of the diaphragms, whereby all the detectors of all of the rows are used substantially simultaneously while the rows of detectors each cover only a fraction of the length of the tangential path along which the respective x-ray beam is moved during each cycle of tangential movement of the respective diaphragm.
Claim 2
Dependent Claim 315 words
A tomographic apparatus for producing transversal layer images of a subject, consisting of an x-ray measuring arrangement with a transmitting arrangement for emitting x-rays and with radiation receivers which determine the intensity of radiation behind the subject by scanning the x-rays, and of a drive system for the measuring arrangement with a rotating frame for producing rotational movements of the x-ray measuring arrangement, the transmitting arrangement comprising a plurality of x-ray tubes with their focuses lying substantially on a common circle, and arranged offset at predetermined angles relative to one another, one ray receiver being provided for each x-ray tube, the x-ray tubes being fixedly mounted on the rotating frame and having pinhole diaphragms for condensing the x-ray beam in such a way that it impinges on the ray receivers, said diaphragms being mounted for movement parallel to a tangent of the circle of rotation of the x-ray tubes and the radiation receivers being mounted for movement parallel to the path of the diaphragm such that the x-ray beam always strikes the ray receivers during movement thereof in the scanning of the subject, the ray receivers each consisting of a row of detectors movable as a group parallel to a tangent of the circle of rotation of the x-ray tubes, all of the detectors of each row being simultaneously impinged by the respective x-ray beam in each position of the respective diaphragm during each cycle of tangential movement of the diaphragms, and the rows of detectors all moving tangentially synchronously with the movement of the respective pinhole diaphragms during each cycle of tangential movement of the diaphragms, whereby all the detectors of all of the rows are used substantially simultaneously while the rows of detectors each cover only a fraction of the length of the tangential path along which the respective x-ray beam is moved during each cycle of tangential movement of the respective diaphragm.
Claim 3
Dependent Claim 15 words
Apparatus according to claim 1, wherein each row of detectors comprises about thirty individual detectors.

References Cited (Backward Citations)

US3141972A Cited
US3549885A Cited
US3944833A Cited
US4057725A Cited
US4031395A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-04-16 1982-10-16 1983-04-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-04-16 1986-10-16 1987-04-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-04-16 1990-10-16 1991-04-17 $7700.00 Window Closed / Lapsed

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