US4903203A
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US
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Bone evaluation method
Assignee: Teijin Ltd
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Filing: 1986-11-12
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Granted: 1990-02-20
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Expires: 2006-11-12
Abstract
Abstract A method for evaluating cancellous bone from a density pattern of the cancellous bone obtained by irradiating the cancellous bone with a radiation wherein trabeculae of the cancellous bone are analyzed based on a power spectrum obtained by a Fourier transformation of the density pattern is provided. Furthermore, a method for evaluating cancellous bone from the density pattern of the cancellous bone obtained by irradiating the cancellous bone with radiation, wherein the density pattern is determined by irradiating the radiation substantially vertically against the main trabecula of the cancellous bone and the degree of the bone atrophy of the cancellous bone is evaluated by using the area (ΣGS) of the density pattern and/or the value (ΣGS/D) obtained by dividing the area (ΣGS) by the bone width (D) of the cancellous bone.
Inventors
- 👤 Gentaro Yamashita
- 👤 Yasuhiro Uotani
- 👤 Yoshio Hirano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:24
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/02; G01N23/04
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
74 words
A method for evaluating cancellous bone comprising the steps of: (a) irradiating cancellous bone with radiation; (b) measuring the transmitted radiation to form a bone density pattern; (c) directly transforming the density pattern by a Fourier transformation as a periodic function of f(x) to a Fourier series: ##EQU4## to determine the Fourier factors An and Bn followed by determining a power spectrum Cn as follows: ##EQU5## and plotting the power spectrum C n .
Claim 2
Independent Claim
74 words
A method for evaluating cancellous bone comprising the steps of: (a) irradiating cancellous bone with radiation; (b) measuring the transmitted radiation to form a bone density pattern; (c) directly transforming the density pattern by a Fourier transformation as a periodic function of f(x) to a Fourier series: ##EQU4## to determine the Fourier factors An and Bn followed by determining a power spectrum Cn as follows: ##EQU5## and plotting the power spectrum C n .
Claim 3
Dependent Claim
23 words
A method according to claim 1, wherein the radiation is a photon beam and the beam density pattern is formed by direct monitoring.
Claim 4
Dependent Claim
28 words
A method according to claim 1, wherein the radiation is X-ray and the density pattern is based on densitometric measurement of an X-ray photograph of the cancellous bone.
Claim 5
Dependent Claim
20 words
A method as in claim 1, wherein the radiation is passed perpendicularly through the main trabeculae of the cancellous bone.
Claim 6
Dependent Claim
21 words
A method according to claim 1, further comprising subtracting a direct current component from the density pattern prior to Fourier transformation.
Claim 7
Dependent Claim
21 words
A method according to claim 5, wherein the direct current component stands for a straight line approximating the bone density pattern.
Claim 8
Dependent Claim
21 words
A method according to claim 5, wherein the direct current component stands for a broad curve approximating the bone density pattern.
Claim 9
Dependent Claim
36 words
A method according to claim 1, wherein the cancellous bone is at least one member selected from the group consisting of a calcaneus, spine, carpal bone, tarsal bone, talus, and an epiphsial portion of long bone.
Claim 10
Dependent Claim
29 words
A method according to claim 1 wherein density measurements are made over at least 10 different 10 millimeter segments of cancellous bone, and the Power Spectra value is averaged.
Claim 11
Dependent Claim
44 words
A method for evaluating cancellous bone according to claim 1 further comprising obtaining the first and second sums of the power spectra at a first and second regions of the power spectra and comparing the first and second sums to obtain a ratio thereof.
Claim 12
Dependent Claim
42 words
A method for evaluating cancellous bone as claimed in claim 10, wherein the first and second regions are a region of from n=5 to n=20 of the power spectra and a region of from n=40 to n=127 of the power spectra, respectively.
Claim 13
Independent Claim
78 words
A method for evaluating a calcaneus comprising the steps of: (a) irradiating the calcaneus substantially perpendicularly against the principle trabeculae of the calcaneus with radiation to obtain a density pattern; (b) calculating the area (ΣGS) of the density pattern; (c) evaluating the degree of the bone atrophy by using the area (ΣGS); (d) transforming the density pattern by Fourier transformation to obtain a power spectrum; and (e) evaluating the trabeculae of the calcaneus based on the power spectrum.
Claim 14
Independent Claim
78 words
A method for evaluating a calcaneus comprising the steps of: (a) irradiating the calcaneus substantially perpendicularly against the principle trabeculae of the calcaneus with radiation to obtain a density pattern; (b) calculating the area (ΣGS) of the density pattern; (c) evaluating the degree of the bone atrophy by using the area (ΣGS); (d) transforming the density pattern by Fourier transformation to obtain a power spectrum; and (e) evaluating the trabeculae of the calcaneus based on the power spectrum.
Claim 15
Dependent Claim
56 words
A method according to claim 12 wherein the Fourier transformation is effected directly from the density pattern as a periodic function of f(x) to a Fourier series: ##EQU6## to determine the Fourier factors An and Bn, followed by determining a power spectrum Cn as follows: ##EQU7## and further comprising plotting the power spectrum C n .
Claim 16
Independent Claim
104 words
A method for evaluating a calcaneus comprising the steps of: (a) irradiating the calcaneus substantially perpendicularly against the principle trabeculae of the calcaneus with radiation to obtain a density pattern; (b) measuring the bone width (D); (c) calculating the area (ΣGS) of the density pattern corresponding to the bone width (D); (d) evaluating the degree of the bone atrophy by using the value (ΣGS/D) obtained by dividing the area (ΣGS) by the bone width (D) of the calcaneus; (e) transforming the density pattern by Fourier transformation to obtain a power spectrum; and (f) evaluating the trabeculae of the calcaneus based on the power spectrum.
Claim 17
Independent Claim
104 words
A method for evaluating a calcaneus comprising the steps of: (a) irradiating the calcaneus substantially perpendicularly against the principle trabeculae of the calcaneus with radiation to obtain a density pattern; (b) measuring the bone width (D); (c) calculating the area (ΣGS) of the density pattern corresponding to the bone width (D); (d) evaluating the degree of the bone atrophy by using the value (ΣGS/D) obtained by dividing the area (ΣGS) by the bone width (D) of the calcaneus; (e) transforming the density pattern by Fourier transformation to obtain a power spectrum; and (f) evaluating the trabeculae of the calcaneus based on the power spectrum.
Claim 18
Dependent Claim
56 words
A method according to claim 14, wherein the Fourier transformation is effected directly from the density pattern as a periodic function of f(x) to a Fourier series: ##EQU8## to determine the Fourier factors An and Bn, followed by determining a power spectrum Cn as follows: ##EQU9## and further comprising plotting the power spectrum C n .
Claim 19
Independent Claim
108 words
A method for evaluating a calcaneus comprising the steps of: (a) irradiating the calcaneus substantially perpendicularly against the principle trabeculae of the calcaneus with radiation to obtain a density pattern; (b) measuring the bone width (D); (c) calculating the area (ΣGS) of the density pattern corresponding to the bone width (D); (d) evaluating the degree of the bone atrophy by using the area (ΣGS/D) and the value (ΣGS/D) obtained by dividing the area (ΣGS) by the bone width (D) of the calcaneus; (e) transforming the density pattern by Fourier transformation to obtain a power spectrum, and (f) evaluating the trabeculae of the calcaneus based on the power spectrum.
Claim 20
Independent Claim
108 words
A method for evaluating a calcaneus comprising the steps of: (a) irradiating the calcaneus substantially perpendicularly against the principle trabeculae of the calcaneus with radiation to obtain a density pattern; (b) measuring the bone width (D); (c) calculating the area (ΣGS) of the density pattern corresponding to the bone width (D); (d) evaluating the degree of the bone atrophy by using the area (ΣGS/D) and the value (ΣGS/D) obtained by dividing the area (ΣGS) by the bone width (D) of the calcaneus; (e) transforming the density pattern by Fourier transformation to obtain a power spectrum, and (f) evaluating the trabeculae of the calcaneus based on the power spectrum.
Claim 21
Dependent Claim
56 words
A method according to claim 16 wherein the Fourier transformation is effected directly from the density pattern as a periodic function of f(x) to a Fourier series: ##EQU10## to determine the Fourier factors An and Bn, followed by determining a power spectrum Cn as follows: ##EQU11## and further comprising plotting the power spectrum C n .
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| 3.5 Years (Year 4) | 1993-02-19 | 1993-08-21 | 1994-02-20 | $2000.00 | Window Closed / Lapsed |
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