Patent US5109397A successfully refreshed from Google Patents.
US5109397A
Expired / Lapsed
US
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X-ray tomography apparatus with lateral movement compensation
Assignee: Analogic Corp
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Filing: 1991-01-22
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Granted: 1992-04-28
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Expires: 2011-01-22
Abstract
Abstract An improved X-ray tomography system includes means for providing error information at each incremental angular position of the 360° rotation of each scan, indicative of any mechanical lateral movements of the various tomography components during a scan, and means for compensating the data derived from the analog information signals representative of X-ray flux detected by the detectors during each projection view as a function of the error information during the back projection process so as to provide accurate scan data.
Inventors
- 👤 Bernard M. Gordon
- 👤 Daniel Abenaim
- 👤 Leopold Neumann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:39
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/52; A61B6/5258; A61B6/5264; A61B6/527; A61B6/02; A61B6/03; A61B6/032; A61B6/035; A61B6/58; A61B6/582; A61B6/583
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
213 words
In an improved X-ray tomography system of the type comprising: (a) X-ray source means, (b) X-ray detection means, and (c) support means for rotationally supporting said source means and detection means so that (i) said source means and detection means rotate about an axis of rotation through a plurality of angular positions in a scanning plane, (ii) X-rays, emitted by said source means and detected by said detection means, are projected within said scanning plane as the support means rotates about the rotation axis, and (iii) a tomographic image of the portion of an object disposed within said scanning plane can be created from data derived as a function of the X-rays received by the detection means at said plurality of positions, wherein the improvement comprises: reference means, fixed so that said scanning plane extends through said reference means and said source means and detection means rotate about said reference means through said plurality of positions, for providing error information indicative of any lateral movement of said source means and said detection means relative to said reference means as said support means rotates about said rotation axis; and means for compensating said data as a function of the error information so that said tomographic image is created substantially free of said error information.
Claim 2
Dependent Claim
213 words
In an improved X-ray tomography system of the type comprising: (a) X-ray source means, (b) X-ray detection means, and (c) support means for rotationally supporting said source means and detection means so that (i) said source means and detection means rotate about an axis of rotation through a plurality of angular positions in a scanning plane, (ii) X-rays, emitted by said source means and detected by said detection means, are projected within said scanning plane as the support means rotates about the rotation axis, and (iii) a tomographic image of the portion of an object disposed within said scanning plane can be created from data derived as a function of the X-rays received by the detection means at said plurality of positions, wherein the improvement comprises: reference means, fixed so that said scanning plane extends through said reference means and said source means and detection means rotate about said reference means through said plurality of positions, for providing error information indicative of any lateral movement of said source means and said detection means relative to said reference means as said support means rotates about said rotation axis; and means for compensating said data as a function of the error information so that said tomographic image is created substantially free of said error information.
Claim 3
Dependent Claim
41 words
The apparatus according to claim 1, wherein said means for compensating said data includes means for sensing the relative position between said reference means and said support means, and for generating said error information as a function of said relative position.
Claim 4
Dependent Claim
46 words
The apparatus according to claim 2, wherein said means for sensing the relative position between said reference means and said support means includes means for sensing the relative position between said reference means and said support means in at least two directions within said scanning plane.
Claim 5
Dependent Claim
34 words
The apparatus according to claim 3, wherein said means for sensing the relative position between said reference means and said support means senses said relative position in two perpendicular directions within said scanning plane.
Claim 6
Dependent Claim
46 words
The apparatus according to claim 3, wherein said means for sensing the relative position between said reference means and said support means further includes means for sensing the relative position between said reference means and said support means in a direction normal to said scanning plane.
Claim 7
Dependent Claim
64 words
The apparatus according to claim 5, wherein said means for sensing the relative position between said reference means and said support means in a direction normal to said scanning plane includes at least three sensors positioned at three locations for sensing the relative position between said reference means and said support means in a direction normal to said scanning plane at said three locations.
Claim 8
Dependent Claim
51 words
The apparatus according to claim 2, wherein said means for sensing the relative position between said reference means and said support means includes proximity detector means for providing a signal representative of the relative distance between the reference means and said support means at the location of said proximity detector means.
Claim 9
Dependent Claim
15 words
The apparatus according to claim 7, wherein said proximity detector means includes a non-contacting sensor.
Claim 10
Dependent Claim
23 words
The apparatus according to claim 8, wherein said non-contacting sensor includes a source of reflective energy and a detector of said reflective energy.
Claim 11
Dependent Claim
15 words
The apparatus according to claim 7, wherein said proximity detector means includes a contacting sensor.
Claim 12
Dependent Claim
14 words
The apparatus according to claim 10, wherein said contacting sensor includes a cam follower.
Claim 13
Dependent Claim
108 words
The apparatus according to claim 2, wherein a portion of said reference means disposed within said plane is shaped so as to intersect at least some of the X-ray paths between said source means and said detection means at each of said positions, and said means for sensing the relative position between said reference means and said support means includes at least two spaced apart X-ray detectors supported by and secured to rotate with said support means so as to receive X-rays (i) emitted by said source means at each of said positions and (ii) representative of the relative position between said reference means and said support means.
Claim 14
Dependent Claim
46 words
The apparatus according to claim 12, wherein said two spaced apart X-ray detectors are positioned on said support means so as to receive X-rays emitted by said source means and passing on opposite sides of said reference means as said support means rotates through said positions.
Claim 15
Dependent Claim
24 words
The apparatus according to claim 2, wherein said reference means includes a ring and said plane intersects said ring so as define a circle.
Claim 16
Dependent Claim
17 words
The apparatus according to claim 1, wherein said reference means includes a material that is X-ray translucent.
Claim 17
Dependent Claim
24 words
The apparatus according to claim 1, wherein said reference means includes means disposed within said plane for indicating the scan quality of said image.
Claim 18
Dependent Claim
28 words
The apparatus according to claim 16, wherein said means for indicating the scan quality of said image includes a target disposed within said plane having a predetermined shape.
Claim 19
Dependent Claim
19 words
The apparatus according to claim 17, wherein said target is made of a material having a known X-ray density.
Claim 20
Dependent Claim
100 words
The apparatus according to claim 1, wherein said reference means defines a reference plane coplanar with said scanning plane when said reference means is properly positioned relative to said support means, wherein said apparatus further includes means for pivotably mounting said reference means relative to said support means so that said reference plane is pivotable relative to said scanning plane about a common pivot axis, and means for moving said support means and said reference means relative to one another about said common pivot axis so that said reference and scanning planes can be properly positioned coplanar with one another.
Claim 21
Dependent Claim
57 words
The apparatus according to claim 19, further including means for sensing the angle of said reference means relative to said support means about said pivot axis, and means responsive to said sensed angle for moving said mounting means and reference means relative to one another so as to maintain said reference plane coplanar with said scanning plane.
Claim 22
Dependent Claim
29 words
The apparatus according to claim 20, wherein said support means includes a patient table for supporting said subject, and said reference means is a ring affixed to said table.
Claim 23
Dependent Claim
53 words
The apparatus according to claim 1, wherein said reference means includes means for defining the angular position of said source means and said detection means relative to said reference means within said scanning plane so that the X-rays received by said detection means include information indicative of each of said plurality of positions.
Claim 24
Dependent Claim
32 words
The apparatus according to claim 22, wherein said reference means defines a reference plane, and said apparatus further includes means for sensing the displacement of said reference plane and said scanning plane.
Claim 25
Dependent Claim
87 words
In an X-Ray apparatus of the type comprising (1) rotatable means for supporting at least an X-ray source so that said X-ray source rotates about an axis of rotation during X-ray operations, (2) means for sensing X-rays, and (3) means for rotating the rotatable means about the axis of rotation during X-ray operations, wherein the improvement comprises: means for sensing any lateral displacement of said rotatable means as said rotatable means rotates about the axis of rotation so as to provide position error data during X-ray operations.
Claim 26
Dependent Claim
87 words
In an X-Ray apparatus of the type comprising (1) rotatable means for supporting at least an X-ray source so that said X-ray source rotates about an axis of rotation during X-ray operations, (2) means for sensing X-rays, and (3) means for rotating the rotatable means about the axis of rotation during X-ray operations, wherein the improvement comprises: means for sensing any lateral displacement of said rotatable means as said rotatable means rotates about the axis of rotation so as to provide position error data during X-ray operations.
Claim 27
Dependent Claim
118 words
In an X-ray apparatus of the type comprising (1) rotatable means for supporting at least X-ray source means so that said X-ray source means rotates about an axis of rotation during X-ray operations, (2) means for sensing X-rays, and (3) means for rotating the rotatable means about the axis of rotation during X-ray operations, wherein the improvement comprises: stationary means positioned relative to said rotatable means so as to remain stationary as said rotatable means rotates about the axis of rotation; and means for determining the relative lateral positional relationship between the rotatable means and the stationary means as said rotatable means rotates about the axis of rotation so as to provide position error data during X-ray operations.
Claim 28
Dependent Claim
118 words
In an X-ray apparatus of the type comprising (1) rotatable means for supporting at least X-ray source means so that said X-ray source means rotates about an axis of rotation during X-ray operations, (2) means for sensing X-rays, and (3) means for rotating the rotatable means about the axis of rotation during X-ray operations, wherein the improvement comprises: stationary means positioned relative to said rotatable means so as to remain stationary as said rotatable means rotates about the axis of rotation; and means for determining the relative lateral positional relationship between the rotatable means and the stationary means as said rotatable means rotates about the axis of rotation so as to provide position error data during X-ray operations.
Claim 29
Dependent Claim
33 words
The apparatus of claim 25, wherein the rotatable means defines a plane of rotation, and further wherein the relative lateral positional relationship is determined in two orthogonal directions within the plane of rotation.
Claim 30
Dependent Claim
48 words
The apparatus of claim 25, wherein the means for determining includes a circularly shaped reference means coaxially located with respect to the axis of rotation and means for detecting the relative lateral position of the guide means with respect to either the rotatable means of the stationary means.
Claim 31
Dependent Claim
12 words
The apparatus of claim 27, wherein the reference means is a ring.
Claim 32
Dependent Claim
52 words
The apparatus of claim 28, wherein the rotatable means is a rotatable collar which defines a first plane of rotation, and further wherein the ring is positioned during X-ray operations so as to lie within a second plane substantially parallel to or coplanar with the first plane of rotation of the collar.
Claim 33
Dependent Claim
32 words
The apparatus of claim 29, wherein the means for detecting includes a pair of position detecting means for detecting the position of the ring within the second plane in two othogonal dimensions.
Claim 34
Dependent Claim
32 words
The apparatus of claim 30, wherein the means for detecting includes a third position detecting means for detecting the position of the ring in the dimension substantially perpendicular to the second plane.
Claim 35
Dependent Claim
33 words
The apparatus of claim 31, further comprising means for determining positioning of the collar in the dimension substantially perpendicular to the first plane of rotation in response to the third position detecting means.
Claim 36
Dependent Claim
52 words
The apparatus of claim 30, wherein the position detecting means include X-ray detectors affixed to the collar and adapted to sense X-rays from the X-ray source means during X-ray operations such that the sensed X-rays contain data which can be used to determine the relative position of the ring and the collar.
Claim 37
Dependent Claim
35 words
The apparatus of claim 33, wherein the ring is made of an X-ray translucent material and includes means for enabling observation of scan quality from a resulting image derived from X-ray operations of said apparatus.
Claim 38
Dependent Claim
21 words
The apparatus of claim 34, wherein the means for enabling observation of scan quality includes target means having a known shape.
Claim 39
Dependent Claim
22 words
The apparatus of claim 34, wherein the means for enabling observation of scan quality includes target means having a known X-ray density.
Claim 40
Dependent Claim
38 words
The apparatus of claim 30, wherein the position detecting means include a pair of mechanical position detectors comprising means for providing electrical signals in response to the mechanically detected lateral position of the ring relative to the collar.
Claim 41
Dependent Claim
24 words
The apparatus of claim 37, wherein the mechanical position detectors are affixed to the collar and the ring is affixed to the stationary means.
Claim 42
Dependent Claim
27 words
The apparatus of claim 30, wherein the means for detecting includes a fourth means for detecting the angular position of the collar with respect to the ring.
Claim 43
Dependent Claim
24 words
The apparatus of claim 28, wherein the stationary means includes a patient table means and the ring is affixed to the patient table means.
Claim 44
Dependent Claim
27 words
The apparatus of claim 27, wherein the means for detecting includes at least one source of reflective energy and at least one detector for the reflective energy.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-04-28 | 1995-10-28 | 1996-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-04-28 | 1999-10-28 | 2000-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-04-28 | 2003-10-28 | 2004-04-28 | $7700.00 | Window Closed / Lapsed |