X-ray or gamma ray systems or devices – Specific application – Absorption
Reexamination Certificate
1999-03-19
2001-06-19
Kim, Robert H. (Department: 2882)
X-ray or gamma ray systems or devices
Specific application
Absorption
C378S054000, C378S037000
Reexamination Certificate
active
06249564
ABSTRACT:
BACKGROUND OF THE INVENTION
Dual photon (or x-ray) energy absorptionmetry projection techniques—also referred to as DPA, DPX or DEXA—have been used for the measurement of bone mineral density and total body composition in patients. Most commonly, total body bone mineral is calculated with full body scans to measure the effects of osteoporosis, for example. Although DEXA enables some level of soft tissue discrimination, the photon energies used are generally too high for doing non mineralogical types of body analysis.
SUMMARY OF THE INVENTION
The problem with existing techniques is the fact that they are not well suited to perform soft tissue, body composition measurements outside the laboratory environment. The systems generally require large scanning beds for total body analysis.
They also employ x-rays of high enough energy to be able to penetrate even the thickest bone in the body. This requirement seriously compromises their ability to analyze soft tissue, because the photon energies used are too high to discriminate well between fat and fat-free soft tissue.
The present invention is directed to a body composition measurement device and method, particularly for soft tissue. As such, it is useful to determine levels of hydration or percent body fat, for example. It relies on the X-ray absorption analysis at a single energy or two or more energies. If only a single energy is used, then it is preferred to measure the length of the x-ray path through the soft tissue of the patient.
In contrast to the prior art, analysis is not performed for the whole body in a total body scan or even a partial body scan. Instead, path length attenuation at only a few discrete locations is taken. Moreover, these locations are selected to avoid any bone along the path. The information on the X-ray absorption is then used to determine the body composition along the path.
Also, in contrast to the conventional approaches, with the present invention, the photon energies used are selected to be low enough to allow good soft tissue analysis, not bone.
In general, according to another aspect, the invention also features a body composition measurement device. This device comprises anthropometry measurement calipers. This can be any appropriate device for measuring the thickness of a skin fold, but large enough to measure the total thickness of a thigh or upper arm. An X-ray source is provided that emits radiation along a measurement path of the calipers and an X-ray detector is used to measure the levels of irradiation that have passed along the path. As a result, this device is most applicable to measurement at only a single energy. The calipers determine the path length. As such, a controller either in the calipers or external to it can combine the information from the calipers and the detector to provide an indication of the body composition along the path.
The above and other features of the invention including various novel details of construction and combinations of parts, and other advantages, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular method and device embodying the invention are shown by way of illustration and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.
REFERENCES:
patent: Re. 33634 (1991-07-01), Yanaki
patent: 4090084 (1978-05-01), Epstein et al.
patent: 4097997 (1978-07-01), Bjornson
patent: 5335257 (1994-08-01), Stunberg
patent: 5459769 (1995-10-01), Brown
patent: 5526394 (1996-06-01), Siczek et al.
patent: 5715820 (1998-02-01), Stein et al.
patent: 6151379 (2000-11-01), Kullenberg et al.
Ken Carr-Brion. X-ray Analysers in Process Control (New York: Elsevier, 1989), p. 8-12.*
B. D. Cullity. Elements of X-ray Diffraction, second edition (Reading, MA: Addison-Wesley, 1978), p. 509-510.*
Huber et al. Nuclear Instruments and Methods in Physics Research B 99, 665 (1995).*
R.B. Mazess, et al., “Total Body Bone Mineral and Lean Body Mass by Dual-Photon Absorptiometry,”Calcif. Tissue Int. 33, pp. 361-363 (1981).
“X-Ray and Gamma Ray Detector High Resolution CZT Cadmium Zinc Telluride,”AMPTEK, Inc., 6 De Angelo Drive, Bedford, Ma 01730-2204 (Advertisement).
R.B. Mazess, et al., “Dual-Energy X-Ray Absorptiometry for Total-Body and Regional Bone-Mineral and Soft-Tissue Composition,”Am J Clin Nutr 51, pp. 1106-1112 (1990).
Hamilton Brook Smith & Reynolds P.C.
Ho Allen C.
Kim Robert H.
Trustees of Tufts College
LandOfFree
Method and system for body composition analysis using x-ray... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and system for body composition analysis using x-ray..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and system for body composition analysis using x-ray... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2495307