Patent ID: 6687532
Filing Date: 2004-02-03
Classification: A61B,B29K,B29L

Abstract:
An optical CT apparatus for measuring optical characteristics of a part of an object having a predetermined optical characteristic, the apparatus comprising:a container for storing a light-transparent medium having an optical characteristic substantially identical, in at least one of a scattering and an absorption coefficient, to an average value of the optical characteristic of the part of the object being measured; light-projecting means for projecting light into said container; light-detecting means for detecting to light protected by said light projecting means; and arithmetic means receiving a projection signal relating to the light projected by said light projecting means and a detection signal relating to the light detected by said light-detecting means, for determining a first characteristic amount relating to an optical characteristic of a scattered light that is transmitted through the medium and measured by use of said light projection means and said light detecting means in a state where the medium is stored within said container, for determining a second characteristic amount relating to an optical characteristic of a scattered light that is transmitted through the medium, and/or the part of the object being measured, and measured by use of said light projection means and said light detecting means in a state where the medium is at least partly replaced by the part of object to be measured, and for calculating a spatial distribution of a characteristic amount of the next of the object to be measured according to a comparison of the first characteristic amount with the second characteristic amount; wherein said arithmetic means comprises: first arithmetic means for assuming the inside of said container to be an assembly model divided into a plurality of volume elements and calculating a degree of influence of a change in a characteristic amount relating to an optical characteristic of each volume element upon a characteristic amount relating to an optical characteristic of the transmitted light detected by said light-detecting means in a case where said light-projecting means and said light-detecting means are used; second arithmetic means for calculating an amount obtained when an optical amount concerning an optical characteristic of the light transmitted through the medium and measured by use of said light-projecting means and said light-detecting means in a state where the medium is accommodated within said container and an optical amount concerning an optical characteristic of the light transmitted through the medium and/or the part of object to be measured and measured by use of said light-projecting means and said light-detecting means in a state where the medium is partly replaced by the part of the object being measured are compared with each other; and third arithmetic means for calculating a spatial distribution of a characteristic amount relating to an optical characteristic of the part of object being measured by calculating a characteristic amount relating to an optical characteristic of each volume element from the degree of influence determined by said first arithmetic means and the amount determined by said second arithmetic means from the comparison of the characteristic amounts relating to optical characteristics.