US 5,204,888 AGranted

Bone mineral content measuring apparatus

AssigneeAloka Co., Ltd.

InventorsToshiaki Tamegai, Kazuyuki Tamura, Shigeo Kimura, Koichi Kawamura, Shizuo Ninomiya

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Abstract

A bone mineral content measuring apparatus for obtaining the bone mineral content of an object to be examined by irradiating X-rays onto the object and measuring the X-rays which have passed through the object. An X-ray generating device generates X-rays having a continuous spectrum. The X-rays generated pass through an X-ray filter before the irradiation of the object or after the transmission of the object. The X-ray filter is composed of a substance having an X-ray absorbing characteristic with the K-absorption edge at a predetermined energy value. The X-rays which have passed through the X-ray filter and the object are detected by the X-ray detector. A data analyzer inputs the detected X-ray detection data and analyzes the bone mineral content of the object on the basis of the X-ray absorbing characteristic of the X-ray filter.

Claims11

Dependent claims

A bone mineral content measuring apparatus comprising:

(a) an X-ray generating device for generating X-rays having a continuous spectrum;
(b) an X-ray detecting device for detecting the X-rays which have passed through an object to be examined;
(c) a filtering device including at least one pair of X-ray filters which are switched over each other and provided in an X-ray beam path between said X-ray generating device and said X-ray detecting device, and a filter switching device for switching said X-ray filters, said pair of X-ray filters being composed of substances having different X-ray absorbing characteristics with K-absorption edges at different energy values which are approximately equal to each other;
(d) a data analyzer for inputting the X-ray detection data from said X-ray detecting device and analyzing said data, said data analyzer including a spectrum subtracter and a bone mineral content analyzing circuit, said spectrum subtracter calculating the difference data between the X-ray detection data obtained by using one of said pair of X-ray filters and the X-ray detection data obtained by using the other of said pair of X-ray filters, said difference data being equivalent to data obtained by using a monochromatic spectrum, and said bone mineral content analyzing circuit providing the bone mineral content of said object on the basis of said difference data;
and
(e) a display unit for displaying the result of analysis of said data analyzer.

3 more elements

Dependencies are inferred from the claim text.