Does anyone know if this is related to Photonics Corp???
United States Patent --- 5,835,617
Ohta, et. al. Nov. 10, 1998
Optical computer tomographic apparatus and image reconstruction method using optical computer tomography
Abstract
An arithmetic control mechanism of the present optical CT apparatus calculates first light densities in output portions of an
object on the basis of a numerical analysis method, when it is assumed that the object is divided into fine segments and all
segments have the same value as an absorption coefficient under predetermined conditions equivalent to an actual
measurements; and calculates second light densities in the output portions on the basis of the method, when it is assumed that
sequentially selected one of the segments has a specific value as an absorption coefficient under the predetermined conditions.
Further, the mechanism calculates, as influences of the segments, ratios of the first to the second light densities, thereby
obtaining an influence matrix corresponding to an arrangement of the segments; calculates relative ratios of the third light
densities in the output portions on the basis of the actual measurements to the fitst light densities, thereby obtaining a relative ratio matrix corresponding to arrangements of input and output portions of the object; and performs a matrix calculation by
using the influence matrix and the relative ratio matrix, thereby obtaining feature data of the segments for reconstructing a
tomographic image of the object.
Inventors: Ohta; Kazuyoshi (Hamamatsu, JP); Ueda; Yukio (Hamamatsu, JP).
Assignee: Hamamatsu Photonics K.K. (Hamamatsu, JP).
Appl. No.: 785,225
Filed: Jan. 17, 1997
Foreign Application Priority Data
Jan. 18, 1996 [JP]
8-006619
Intl. Cl. : G06K 9/00, A61B 6/00
Current U.S. Cl.: 382/131; 378/4; 378/901; 382/128
Field of Search: 382/131, 128, 130, 154, 282, 284; 378/901, 4, 21, 74, 86, 87,89; 364/751, 736.01, 468.25; 356/379, 377, 325
References Cited | [Referenced By]
U.S. Patent Documents
4,375,695 Mar., 1983 Harding et al. 378/6
4,672,651 Jun., 1987 Horiba et al. 378/9
5,070,455 Dec., 1991 Singer et al. 364/413.14
5,137,355 Aug., 1992 Barbour et al. 356/342
Foreign Patent Documents
0 561 643 Sept., 1993 EP 378/4
0 614 645 Sept., 1994 EP 378/4
Other References
Pogue et al, "Forward and Inverse Calculations for 3-D Frequency-Domain Diffuse Optical Tomography", SPIE, vol.
2389, pp. 328-339.
Schotland et al, "Photon Hitting Density", Applied Optics, vol. 32, No. 4, Feb. 1, 1993, pp. 448-453.
Dolne et al, "Analysis of Time-Resolved Data for Tomographical Image Reconstruction of Opague Phantoms and Finite Absorbers in Diffusive Media", SPIE, vol. 2389, pp. 16-29.
Primary Examiner: Couso; Jose L.
Assistant Examiner: Dang; Duy M.
Attorney, Agent or Firm: Pillsbury Madison & Sutro LLP
24 Claims, 23 Drawing Figures |
