Patent EP0299906A2 successfully refreshed from Google Patents.
EP0299906A2
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EP
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In-vivo bone quality measurement
Assignee: University of Melbourne
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Filing: 1988-07-14
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Granted: —
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Expires: 2008-07-14
Abstract
Abstract A method of determining in-vivo an estimate of the modulus of elasticity of a bone, comprising the steps of: (a) applying an ultrasound beam to a limb from a transmitting transducer to a receiving transducer; (b) measuring the flight times for an ultrasound beam along a first path T s through the cortex of the bone, and along a second path T m through the cortex and medulla of said bone; (c) calculating the diameter X of the bone from the external diameter of the limb less a predetermined constant allowing for skin and flesh; (d) calculating the apparent velocity C a from X divided by T s ; (e) calculating the mean velocity V from X divided by T m ; (f) calculating the cortical bone velocity C bE from a predetermined function f multiplied by C a ; (g) determining the ratio R of the diameter of the medulla to the diameter of the cortex; (h) estimating the cross-sectional area CSA E of the bone from the values of the diameter X, the ratio R and from predetermined constants; (i) determining the bone mineral content BMC; (j) determining the estimated compact bone density CBD E , and (k) determining an estimate of the modulus of elasticity from the product of CBD E and C bE .
Inventors
- 👤 Leo Broof Jeffcott
- 👤 Ronald Norman Mccartney
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 10:33
CPC Classifications
A; A61; A61B; A61B8/00; A61B8/08; A61B8/0858; A61B8/0875
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
175 words
A method of determining in-vivo an estimate of the modulus of elasticity of a bone, comprising the steps of passing a beam of ultrasound from a transmitting transducer through the bone to a receiving transducer, determining the distance between said transducers and correcting that distance to obtain a measure of the diameter of said bone, measuring the time of transmission of ultrasound beam along a first path through the cortex of said bone and along a second path through the cortex and medulla of said bone, calculating the velocity of said beam along said first path and along said second path and using said velocity values to calculate an estimate of the transverse cortical bone velocity and the ratio of the diameter of the medulla to the diameter of the cortex, calculating an estimate of the cross sectional area of the cortex, measuring the bone mineral content of the bone and using said estimated cross sectional area and said measured bone mineral content to calculate an estimate of the modulus of elasticity of the bone.
Claim 2
Independent Claim
175 words
A method of determining in-vivo an estimate of the modulus of elasticity of a bone, comprising the steps of passing a beam of ultrasound from a transmitting transducer through the bone to a receiving transducer, determining the distance between said transducers and correcting that distance to obtain a measure of the diameter of said bone, measuring the time of transmission of ultrasound beam along a first path through the cortex of said bone and along a second path through the cortex and medulla of said bone, calculating the velocity of said beam along said first path and along said second path and using said velocity values to calculate an estimate of the transverse cortical bone velocity and the ratio of the diameter of the medulla to the diameter of the cortex, calculating an estimate of the cross sectional area of the cortex, measuring the bone mineral content of the bone and using said estimated cross sectional area and said measured bone mineral content to calculate an estimate of the modulus of elasticity of the bone.
Claim 3
Independent Claim
218 words
A method of determining in-vivo an estimate of the modulus of elasticity of a bone, comprising the steps of: (a) applying an ultrasound beam to a limb from a transmitting transducer to a receiving transducer; (b) measuring the flight times for an ultrasound beam along a first path T s through the cortex of the bone, and along a second path T m through the cortex and medulla of said bone; (c) calculating the diameter X of the bone from the external diameter of the limb less a predetermined constant allowing for skin and flesh; (d) calculating the apparent velocity C a from X divided by T a ; (e) calculating the mean velocity V from X divided by T m ; (f) calculating the cortical bone velocity C bE from a predetermined function f multiplied by C a ; (g) determining the ratio R of the diameter of the medulla to the diameter of the cortex; (h) estimating the cross-sectional area CSA E of the bone from the values of the diameter X, the ratio R and from predetermined constants; (i) determining the bone mineral content BMC; (j) determining the estimated compact bone density CBD E , and (k) determining an estimate of the modulus of elasticity from the product of CBD E and C bE .
Claim 4
Independent Claim
218 words
A method of determining in-vivo an estimate of the modulus of elasticity of a bone, comprising the steps of: (a) applying an ultrasound beam to a limb from a transmitting transducer to a receiving transducer; (b) measuring the flight times for an ultrasound beam along a first path T s through the cortex of the bone, and along a second path T m through the cortex and medulla of said bone; (c) calculating the diameter X of the bone from the external diameter of the limb less a predetermined constant allowing for skin and flesh; (d) calculating the apparent velocity C a from X divided by T a ; (e) calculating the mean velocity V from X divided by T m ; (f) calculating the cortical bone velocity C bE from a predetermined function f multiplied by C a ; (g) determining the ratio R of the diameter of the medulla to the diameter of the cortex; (h) estimating the cross-sectional area CSA E of the bone from the values of the diameter X, the ratio R and from predetermined constants; (i) determining the bone mineral content BMC; (j) determining the estimated compact bone density CBD E , and (k) determining an estimate of the modulus of elasticity from the product of CBD E and C bE .
Claim 5
Dependent Claim
30 words
The method of claim 2, wherein said predetermined constant for determining the diameter X is experimentally determined from examination of skin and flesh thicknesses of a multiplicity of said limbs.
Claim 6
Dependent Claim
92 words
The method of claim 3 wherein said function f being empirically determined from 1 - R c ² + R c . arsin R c , said estimated cross sectional area CSA E being determined from M .π/4 . X² (K - L . R²), where K is an ovality factor for the external cortical bone cross section, L is an ovality factor for the medulla and M is a factor to take account of the area of the splint bones (MC2 and MC4), each of said factors being experimentally determined constants.
Claim 7
Dependent Claim
17 words
The method of claim 4, wherein said bone mineral content BMC is determined using a bone densitometer.
Claim 8
Independent Claim
165 words
An apparatus for determining in-vivo an estimate of the modulus of elasticity of a bone comprising a pair of transducers for transmitting an ultrasound beam through the bone along a first path through the cortex of said bone and along a second path through the cortex and medulla of said bone, means for determining the distance between said transducers and for correcting that distance to obtain a measure of the diameter of said bone, means for determining the time of transmission of said ultrasound beam along said first and second paths, means for calculating the velocity of said beam along said first and second paths and for calculating an estimate of the transverse cortical bone velocity and the ratio of the diameter of the medulla to the diameter of the cortex, and means for calculating an estimate of the cross-sectional area of the cortex and for calculating from this information and from separately derived information an estimate of the modulus of elasticity of the bone.
Claim 9
Independent Claim
165 words
An apparatus for determining in-vivo an estimate of the modulus of elasticity of a bone comprising a pair of transducers for transmitting an ultrasound beam through the bone along a first path through the cortex of said bone and along a second path through the cortex and medulla of said bone, means for determining the distance between said transducers and for correcting that distance to obtain a measure of the diameter of said bone, means for determining the time of transmission of said ultrasound beam along said first and second paths, means for calculating the velocity of said beam along said first and second paths and for calculating an estimate of the transverse cortical bone velocity and the ratio of the diameter of the medulla to the diameter of the cortex, and means for calculating an estimate of the cross-sectional area of the cortex and for calculating from this information and from separately derived information an estimate of the modulus of elasticity of the bone.
References Cited (Backward Citations)
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