Patent US3673394A successfully refreshed from Google Patents.
US3673394A
Expired / Lapsed
US
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Measuring method and apparatus
Assignee: Boeing North American Inc
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Filing: 1969-02-18
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Granted: 1972-06-27
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Expires: 1989-02-18
Abstract
Abstract Measurement of the shape, location, and density of a hidden object is provided by passing energy such as X-rays through the object in two mutually angulated directions and measuring the changes in energy. The measured changes in the two directions are then combined to reconstruct the shape of the hidden object. Details of a number of reconstruction techniques are set forth. There is disclosed a reconstruction by hand; the basis for reconstruction by a general purpose computer; a special purpose computer for shape reconstruction; and an alternative solution which may be by hand or by computer.
Inventors
- 👤 Frederick Hartmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:57
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/02; G01N23/04; A; A61; A61B; A61B6/00; A61B6/02; A61B6/12
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
237 words
A method of generating sets of data from which the shape of a cross-section of an object may be determined comprising the steps of: passing X-rays through the object in a first direction; passing X-rays through the object in a second direction; passing X-rays through a standard of known absorption; measuring X-ray intensity after passing through said standard for correlating X-ray intensity and absorption; measuring changes in X-ray intensity after passing through the object in the first direction along a plane parallel to the first and second directions for determining thickness of the object within the plane in the first direction; measuring changes in X-ray intensity after passing through the object in the second direction along said plane for determining thickness of the object within said plane in the second direction; and said standard of known absorption comprises: a first wedge having a first absorptivity, a substantially rectangular base, a pair of substantially rectangular faces intersecting at a first edge, and a pair of triangular faces; a second wedge having a second absorptivity, a substantially rectangular base, a pair of substantially rectangular faces intersecting at a second edge, and a pair of triangular faces, one of the substantially rectangular faces of said second wedge being substantially coterminous with one of the substantially rectangular faces of said first wedge and with said second edge lying along an edge of one of the triangular faces of said first wedge.
Claim 2
Independent Claim
237 words
A method of generating sets of data from which the shape of a cross-section of an object may be determined comprising the steps of: passing X-rays through the object in a first direction; passing X-rays through the object in a second direction; passing X-rays through a standard of known absorption; measuring X-ray intensity after passing through said standard for correlating X-ray intensity and absorption; measuring changes in X-ray intensity after passing through the object in the first direction along a plane parallel to the first and second directions for determining thickness of the object within the plane in the first direction; measuring changes in X-ray intensity after passing through the object in the second direction along said plane for determining thickness of the object within said plane in the second direction; and said standard of known absorption comprises: a first wedge having a first absorptivity, a substantially rectangular base, a pair of substantially rectangular faces intersecting at a first edge, and a pair of triangular faces; a second wedge having a second absorptivity, a substantially rectangular base, a pair of substantially rectangular faces intersecting at a second edge, and a pair of triangular faces, one of the substantially rectangular faces of said second wedge being substantially coterminous with one of the substantially rectangular faces of said first wedge and with said second edge lying along an edge of one of the triangular faces of said first wedge.
Claim 3
Independent Claim
524 words
A method of generating sets of data from which the shape of a cross-section of an object may be determined comprising the steps of: passing a first X-ray beam through the object in a first direction and through a first wedge of material having a known absorption; passing a second X-ray beam through the object in a second direction, and through a second wedge of material having a known absorption; photographically recording the X-ray intensity after passing through said object and said first wedge in said first direction; photographically recording the X-ray intensity after passing through said object and said second wedge in said second direction measuring in movements photographic density as formed by said object on both recording and respective lines that lie within the same plane; measuring in movements photographic density as formed by said respective wedges in a direction of varying thickness of said wedge for for correlating photographic density and absorption; digitizing the changes in energy in increments along the first one of said lines in Ax values representative of breadth of the object in the first direction; digitizing the changes in energy to increments along the second one of said lines in Ay values representative of breadth of the object in the second direction; identifying at least one region bounded by a closed curve in a two dimensional matrix having a breadth in the first direction of m and a breadth in the second direction of n, said region having first and second breadth values corresponding to the digitized values representative of object breadth; designating elements Axy of the matrix with the region by 1''s; designating elements Axy of the matrix without the region by 0''s; inserting a 1 in each element Axy where (n - Ay + 1) < or = x < or = Ay; inserting a 1 in each element Axy where (m - Ax + 1) < or = y < or = Ax; inserting a 0 in each element Axy where 1 < or = x < or = (xmax - Ay), where xmax is the x coordinate of the highest matrix element occupied by a 1; inserting an 0 in each element Axy where 1 < or = y < or = (ymax - Ax), where ymax is the y coordinate of the furthest matrix element occupied by a 1; inserting a 0 in each element Axy where (ymin + Ay) < or = y < or = m, where ymin is the y coordinate of the nearest matrix element occupied by a 1; inserting a 1 in each element Axy where (n'' - Ay + 1) < or = x < or = Ay, where n'' equals n less the number of matrix elements in a matrix line occupied by a 0; inserting a 1 in each element Axy where (m'' - Ax + 1) < or = y < or = Ax, where m'' equals m less the number of matrix elements in a matrix line occupied by a 0; and repeating said inserting steps until substantially all of the matrix elements Axy are occupied by either 1 or a 0.
Claim 4
Independent Claim
524 words
A method of generating sets of data from which the shape of a cross-section of an object may be determined comprising the steps of: passing a first X-ray beam through the object in a first direction and through a first wedge of material having a known absorption; passing a second X-ray beam through the object in a second direction, and through a second wedge of material having a known absorption; photographically recording the X-ray intensity after passing through said object and said first wedge in said first direction; photographically recording the X-ray intensity after passing through said object and said second wedge in said second direction measuring in movements photographic density as formed by said object on both recording and respective lines that lie within the same plane; measuring in movements photographic density as formed by said respective wedges in a direction of varying thickness of said wedge for for correlating photographic density and absorption; digitizing the changes in energy in increments along the first one of said lines in Ax values representative of breadth of the object in the first direction; digitizing the changes in energy to increments along the second one of said lines in Ay values representative of breadth of the object in the second direction; identifying at least one region bounded by a closed curve in a two dimensional matrix having a breadth in the first direction of m and a breadth in the second direction of n, said region having first and second breadth values corresponding to the digitized values representative of object breadth; designating elements Axy of the matrix with the region by 1''s; designating elements Axy of the matrix without the region by 0''s; inserting a 1 in each element Axy where (n - Ay + 1) < or = x < or = Ay; inserting a 1 in each element Axy where (m - Ax + 1) < or = y < or = Ax; inserting a 0 in each element Axy where 1 < or = x < or = (xmax - Ay), where xmax is the x coordinate of the highest matrix element occupied by a 1; inserting an 0 in each element Axy where 1 < or = y < or = (ymax - Ax), where ymax is the y coordinate of the furthest matrix element occupied by a 1; inserting a 0 in each element Axy where (ymin + Ay) < or = y < or = m, where ymin is the y coordinate of the nearest matrix element occupied by a 1; inserting a 1 in each element Axy where (n'' - Ay + 1) < or = x < or = Ay, where n'' equals n less the number of matrix elements in a matrix line occupied by a 0; inserting a 1 in each element Axy where (m'' - Ax + 1) < or = y < or = Ax, where m'' equals m less the number of matrix elements in a matrix line occupied by a 0; and repeating said inserting steps until substantially all of the matrix elements Axy are occupied by either 1 or a 0.
Claim 5
Dependent Claim
147 words
A process for measuring the shape of an object comprising the steps of: passing energy through the object in a first direction whereby the energy transmitted through the object is related to the thickness at the region of transmission; passing energy in a second direction whereby the energy transmitted through the object is related to the thickness at the region of transmission; measuring along a first line the amount of energy transmitted through said object along a plane parallel to the radiating energy which is radiating along said first direction; measuring along a second line said first and second directions the amount of energy transmitted through said object also along said plane which energy is radiating along said second direction said first and second lines both lying in said plane; reconstructing the cross-sectional shape of the object in the said plane from both of said measuring steps.
Claim 6
Dependent Claim
147 words
A process for measuring the shape of an object comprising the steps of: passing energy through the object in a first direction whereby the energy transmitted through the object is related to the thickness at the region of transmission; passing energy in a second direction whereby the energy transmitted through the object is related to the thickness at the region of transmission; measuring along a first line the amount of energy transmitted through said object along a plane parallel to the radiating energy which is radiating along said first direction; measuring along a second line said first and second directions the amount of energy transmitted through said object also along said plane which energy is radiating along said second direction said first and second lines both lying in said plane; reconstructing the cross-sectional shape of the object in the said plane from both of said measuring steps.
Claim 7
Dependent Claim
37 words
A process as defined in claim 3 whereby said passing steps each comprise passing a beam of X-rays through said object; and said measuring steps each comprise measuring the transmitted X-ray intensity after passing through said object.
Claim 8
Dependent Claim
61 words
A process as defined in claim 4 each of said measuring steps further comprises: photographically recording separately X-ray intensity after passing through said object from both directions; measuring photographic density in increments along said respective lines, recordings; and said reconstructing step further comprises: converting photographic density to breadth of said object in both said first and second directions within said plane.
Claim 9
Dependent Claim
100 words
A process as defined in claim 3 wherein said reconstructing step further comprises: digitizing the changes in energy in increments along the first line in values representative of breadth of the object in the first direction in the common plane; digitizing the changes in energy in increments along the second line in values representative of breadth of the object in the second direction in the common plane; and identifying at least one region bounded by a closed curve in a two dimensional matrix, said region having first and second breadth values corresponding to the digitized values representative of object breadth.
Claim 10
Dependent Claim
96 words
A process as defined in claim 6 wherein said identifying step comprises: repetitively tentatively placing the digitized values of change in the first direction as first contiguous sets of elements in rows of the matrix, each of said sets having a number of elements corresponding to a digitized value; repetitively comparing the tentative row position with digitized values of change in the second direction considered as second contiguous sets of elements in columns of the matrix to establish acceptablE locations of contiguous sets in both rows and columns within the region bounded by a closed curve.
Claim 11
Dependent Claim
40 words
A process as defined in claim 7 wherein said placing steps successively place the first sets in all feasible positions in successive rows; and said comparing steps comprise eliminating unacceptable locations of first contiguous sets from further tentative placing steps.
Claim 12
Dependent Claim
51 words
A process as defined in claim 8 wherein said comparing step comprises: reducing the number of elements in the second sets an amount corresponding to locations in columns occupied by elements of the first contiguous sets, and eliminating locations as unacceptable when the reduced value is less than a preselected minimum.
Claim 13
Dependent Claim
48 words
A process as defined in claim 6 wherein said identifying step comprises: identifying a first sub-region within the matrix necessarily within said region; identifying a second sub-region within the matrix necessarily without said region; and iterating the identifying steps alternately until the intersection of subregions determines said region.
Claim 14
Dependent Claim
57 words
A process as defined in claim 10 wherein said step of identifying the first sub-region comprises: arraying the digitized values as parallel contiguous sets of elements adjacent opposite margins of the matrix; and combining said sets of elements for identifying a sub-region wherein elements of sets adjacent one margin overlap elements of sets adjacent the opposite margin.
Claim 15
Dependent Claim
72 words
A process as defined in claim 11 wherein said steps of identifying the second sub-region comprises: overlapping contiguous sets of elements with the first sub-region necessarily within said region so that one end of a contiguous set of elements in a line coincides with an edge of the first sub-region; and identifying matrix elements beyond the opposite end of the contiguous set of elements as the second sub-region necessarily without said region.
Claim 16
Dependent Claim
152 words
A process as defined in claim 6 wherein elements of the matrix within the region are designated by proven 1''s, elements of the matrix without the region are designated by proven 0''s and the digitized values representative of breadth of the object of each matrix line are designated by a contiguous set of 1''s, and wherein the identifying step comprises: inserting proven 1''s in those spaces where the set of 1''s in the respective line adjacent one margin overlaps the same set of 1''s adjacent the opposite margin at the center of all lines in which more than half the length is occupied by the set of 1''s; and inserting proven 0''s at the ends of those lines where proven 1''s have been inserted by a previous inserting step, and the set of 1''s in the respective line cannot extend to the margin from the most remote proven 1 in that line.
Claim 17
Dependent Claim
103 words
A process as defined in claim 13 further comprising: inserting proven 1''s in those spaces where the set of 1''s in a respective line plus the sum of all proven 0''s in the same line, adjacent one margin overlaps the same set of 1''s and sum of all proven 0''s, adjacent the opposite margin on all lines in which more than half of the length is occupied by the sum of all proven 0''s in the line plus the set of 1''s in the line; and iterating the latter two inserting steps alternately until no further proven 0''s or proven 1''s are obtained.
Claim 18
Dependent Claim
134 words
A process as defined in claim 14 further comprising: inserting proven 1''s in those unoccupied spaces occurring in the same line between spaces occupied by proven 1''s; inserting proven 0''s in those unoccupied spaces that occur between the margin of the matrix and a space occupied by a proven 0, or between two proven 0''s in the same line if the number of unoccupied spaces therebetween is insufficient to accomodate the set of 1''s occurring in that line; inserting prOven 0''s in all unoccupied spaces in a line if the number of proven 1''s equals the set of 1''s for that line; and inserting proven 1''s in all unoccupied spaces in a line if the number of proven 0''s in the line equals the matrix breadth less the set of 1''s in the line.
Claim 19
Dependent Claim
53 words
A process as defined in claim 3 further including the steps of: measuring the amount of energy transmitted through said object along a plurality of planes parallel to said plane; reconstructing more than one of said cross-sectional shapes in respective parallel planes; and combining said cross-sectional shapes to reconstruct the three dimensional shape.
Claim 20
Independent Claim
176 words
A method of generating sets of data from which the shape of a cross-section of an object may be determined comprising the steps of: passing energy through the object in a first direction, at the same time passing the energy through a first wedge wherein the wedge is disposed so that the energy passes through different thicknesses thereof; comparing changes in energy that passed through the object in the first direction with the changes in energy passed through the first wedge for determining thickness of the object in the first direction along a plane parallel to the first direction; passing energy through the object in a second direction that is also parallel to the plane and at the same time passing therethrough a second wedge wherein the second wedge is disposed so that the energy passes through different thicknesses thereof; and comparing changes in energy passed in the second direction through the object with changes in energy passed through the second wedge for determining thickness of the object in the second direction also along said plane.
Claim 21
Independent Claim
176 words
A method of generating sets of data from which the shape of a cross-section of an object may be determined comprising the steps of: passing energy through the object in a first direction, at the same time passing the energy through a first wedge wherein the wedge is disposed so that the energy passes through different thicknesses thereof; comparing changes in energy that passed through the object in the first direction with the changes in energy passed through the first wedge for determining thickness of the object in the first direction along a plane parallel to the first direction; passing energy through the object in a second direction that is also parallel to the plane and at the same time passing therethrough a second wedge wherein the second wedge is disposed so that the energy passes through different thicknesses thereof; and comparing changes in energy passed in the second direction through the object with changes in energy passed through the second wedge for determining thickness of the object in the second direction also along said plane.
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) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |