← Back to Patent Explorer
US3840747A Expired / Lapsed US ⏱️ 0.0 years remaining

Gamma ray imaging system

Assignee: Individual
•
Filing: 1973-04-09
•
Granted: 1974-10-08
•
Expires: 1993-04-09
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A multi-aperture plate is placed between a radioactive source and a gamma ray camera. This creates a sum of images, each seen through a different aperture position. Each aperture image is cyclically modulated with a moving shutter. On reconstruction the individual images are demodulated by using their carrier signals. The individual images are translated and combined to view any section of the radioactive source.

Inventors

  • 👤 A Macovski

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 19:14
CPC Classifications
G; G21; G21K; G21K1/00; G21K1/02; G21K1/04; G01; G01T; G01T1/00; G01T1/29; G01T1/2914; G01T1/2921; G01T1/295; G01T1/2985; G21K1/043; A; A61; A61B; A61B6/00; A61B6/42; A61B6/4208; A61B6/4258

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 107 words
Apparatus for imaging a source of gamma rays comprising: detector means for generating a position signal indicating the position of gamma rays emitted from the source; an aperture plate positioned between the source and the detector having a plurality of apertures; a plurality of shutters for modulating the plurality of apertures with a plurality of orthogonal functions; means for deriving a plurality of shutter signals synchronous with the plurality of orthogonal functions; means for processing the position signal, using the plurality of shutter signals, to derive information about the intensity distribution of the source; and means for displaying the information about the intensity distribution of the source.
Claim 2
Dependent Claim 107 words
Apparatus for imaging a source of gamma rays comprising: detector means for generating a position signal indicating the position of gamma rays emitted from the source; an aperture plate positioned between the source and the detector having a plurality of apertures; a plurality of shutters for modulating the plurality of apertures with a plurality of orthogonal functions; means for deriving a plurality of shutter signals synchronous with the plurality of orthogonal functions; means for processing the position signal, using the plurality of shutter signals, to derive information about the intensity distribution of the source; and means for displaying the information about the intensity distribution of the source.
Claim 3
Dependent Claim 94 words
Apparatus as recited in claim 1 wherein the means for processing the position signal includes: a plurality of storage devices for storing the images as seen from each aperture; means for adding counts from the position signal to the corresponding position in each storage device when the shutter signal corresponding to that storage device indicates that the appropriate aperture is open; and means for subtracting counts from the position signal from the corresponding position in the storage device when the shutter signal corresponding to that storage device indicates that the appropriate aperture is closed.
Claim 4
Dependent Claim 70 words
Apparatus as recited in claim 2 including a summing storage device for storing information about a selected depth plane; means for translating the images of each of the plurality of storage devices an amount determined by the position of the corresponding aperture and the selected depth plane; means for adding all of the translated images in the summing storage device whereby the image of the selected depth plane is formed.
Claim 5
Dependent Claim 29 words
Apparatus as recited in claim 2 wherein the means for displaying the information includes a stereoscopic viewer for viewing pairs of stored images as seen from two different apertures.
Claim 6
Dependent Claim 53 words
Apparatus as recited in claim 2 wherein the means for displaying the information is an integral photography system including an array of spherical lenses adjacent to a photographic film with each of the stored images photographed in their correct relative position whereby the developed integral photograph provides a three-dimensional image of the source.
Claim 7
Dependent Claim 57 words
Apparatus as recited in claim 2 wherein the means for displaying the information is a holographic system including a transparency on which each stored image has been recorded in its correct relative position as an interference pattern with a coherent reference beam whereby the transparency, when illuminated with coherent light, provides a three-dimensional image of the source.
Claim 8
Dependent Claim 120 words
Apparatus as recitd in claim 1 wherein the means for processing the position signal comprises: a summing storage device for storing information about a selected depth plane; means for generating a plurality of translated signals by translating the coordinates of the position signal an amount corresponding to the position of each of the plurality of apertures and the selected depth plane; means for adding counts from each of the plurality of translated signals to the corresponding position in the summing storage device when the shutter signal corresponding to that aperture is open; and means for subtracting counts from each of the plurality of translated signals in the summing storage device when the shutter signal corresponding to that aperture is closed.
Claim 9
Dependent Claim 22 words
Apparatus as recited in claim 7 including means for storing the position signal whereby any selected depth plane may subsequently be derived.
Claim 10
Dependent Claim 17 words
Apparatus as recited in claim 1 wherein the plurality of orthogonal functions includes waveforms of different frequencies.
Claim 11
Dependent Claim 22 words
Apparatus as recited in claim 9 wherein the plurality of orthogonal functions includes waveforms of the same frequency in quadrature phase relationship.
Claim 12
Dependent Claim 26 words
Apparatus as recited in claim 9 wherein the total time for collecting gamma rays contains an integral number of cycles of every waveform of different frequency.
Claim 13
Dependent Claim 24 words
Apparatus as recited in claim 9 wherein every waveform is symmetrical, having an open shutter interval with the same duration as the closed interval.
Claim 14
Dependent Claim 48 words
Apparatus as recited in claim 1 wherein the plurality of shutters for modulating the plurality of apertures comprises: a shutter plate having a plurality of slots; and means for moving the shutter plate with respect to the aperture plate so that the slots periodically coincide with the apertures.
Claim 15
Dependent Claim 39 words
Apparatus as recited in claim 13 wherein the shutter plate is a rotatable disc and the plurality of slots are positioned uniformly on concentric circles of the disc, with the slots of each circle having a different angular frequency.
Claim 16
Dependent Claim 28 words
Apparatus as recited in claim 14 wherein the aperture plate contains two apertures on each concentric circle corresponding to quadrature phases of the frequency generated by the slots.
Claim 17
Dependent Claim 50 words
Apparatus as recited in claim 1 wherein the plurality of shutters for modulating the plurality of apertures includes a plurality of rotatable members each containing an integral number of vanes mounted adjacent to the aperture plate whereby the rotating vanes periodically interrupt the transmission of gamma rays through the apertures.
Claim 18
Dependent Claim 27 words
Apparatus as recited in claim 16 wherein two apertures, corresponding to quadrature phases of the frequency generated by the rotating vanes, are used with each rotating member.
Claim 19
Dependent Claim 48 words
Apparatus as recited in claim 1 wherein the plurality of apertures in the aperture plate are arranged so that when an image of the aperture plate is translated with respect to the aperture plate in any direction; not more than one aperture will coincide at any translated position.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-10-07 1978-04-08 1978-10-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-10-07 1982-04-08 1982-10-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-10-07 1986-04-08 1986-10-08 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag