Examination apparatus

• US 5,090,415 A
• Filed: 01/11/1991
• Issued: 02/25/1992
• Est. Priority Date: 02/14/1989
• Status: Expired due to Term

• Current Assignee: Hamamatsu Photonics KK
• Original Assignee: Hamamatsu Photonics KK
• Inventors: Yamashita, Yutaka, Yamashita, Takaji
• Primary Examiner(s): JAWORSKI, FRANCIS J
• Application Number:
  US07/639,377
• Time in Patent Office: 410 Days
• Field of Search: 128/633, 128/634, 128/665
• US Class Current: 600/476
• CPC Class Codes: A61B 5/14553 specially adapted for cerebral tissue
• CPC Class Codes: A61B 5/6814 Head
• CPC Class Codes: G01N 2021/178 Methods for obtaining spatial resolution of the property being measured
• CPC Class Codes: G01N 2021/1791 stroboscopic; pulse gated; time range gated
• CPC Class Codes: G01N 2021/4709 Backscatter
• CPC Class Codes: G01N 21/4795 spatially resolved investigating of object in scattering medium in vivo A61B
• CPC Class Codes: G01N 2201/08 Optical fibres; light guides

Abstract

An examination apparatus for examining with transmission photometry an object of interest. The apparatus comprises: light launching means for successively launching an incidence light beam to the object at an incidence site; and light pickup means for picking up, in synchronism with launching of the incidence light beam, light beams scattered in the object from a plurality of output sites as light intensity data, and performing mathematical processing on the light intensity data for every launching of said incidence light beam to obtain absorption data representing a light absorption quantity at the incidence site.

Claims

1. An examination apparatus for examining an object composed of tissue employing transmission photometry, comprising:

light launching means for successively launching an incidence light beam to said object composed of tissue, said incidence light beam having a predetermined wavelength, and said light launching means comprising means for cyclically launching incidence light beams to said object at a plurality of incidence sites;

means, comprising a plurality of light-receiving means positioned at least adjacent a plurality of output sites, for picking up, in synchronism with each successive launching of said incidence light beam, light beams of said predetermined wavelength scattered in said object from said plurality of output sites as light intensity data, and for performing mathematical processing on said light intensity data for each successive launching of said incidence light beam to obtain absorption data representing a light absorption quantity at said incidence site;

wherein said means for picking up light beams and for mathematical processing picks up, in synchronism with each launching of said incidence light beam at any incidence site, said light beams scattered in said object from said plurality of output sites as said light intensity data, and performs said mathematical processing on said light intensity data for each launching of said incidence light beam at any incidence site to obtain total absorption data representing light absorption quantities at said plurality of incidence sites; and

wherein said means for performing mathematical processing adds said light intensity data picked up from said plurality of output sites.

2. An examination apparatus according to claim 1, wherein said means for picking up light beams and for performing mathematical processing comprises a single photodetector which adds said light intensity data.

3. An examination apparatus according to claim 2, wherein said means for picking up light beams and for mathematical processing further comprises an integrator for integrating outputs of said photodetector at predetermined times of launching of said incidence light beam.

4. An examination apparatus according to claim 1, wherein said means for picking up light beams and for mathematical processing comprises:

a plurality of photodetectors for detecting said respective light beams scattered in said object to produce said light intensity; and

computing means for adding said light intensity data.

5. An examination apparatus according to claim 1, wherein said means for picking up light beams and performing mathematical processing adds said light intensity data from each launching of said incidence light beam to obtain said absorption data and integrates said absorption data from launching said incidence light beams at each of said plurality of incidence sites to obtain said total absorption data.

6. An examination apparatus according to claim 1, wherein said light launching means is for launching an incidence light beam of a second wavelength for each launching of said incidence light beam of said predetermined wavelength and said means for picking up light beams of said predetermined wavelength and for mathematical processing further comprises means for picking up said light beams of said second wavelength scattered in said object from said plurality of output sites as second light intensity data, and for performing mathematical processing on said second light intensity data for each launching of said incident light beam of said second wavelength to obtain second absorption data representing a second light absorption quantity at said incidence site.

7. An examination apparatus according to claim 1, wherein said means for performing mathematical processing by adding calculates M_i where

said light intensity data at an output site j is represented as M_ij ;

said absorption data at said incidence site i is represented as M_i ; and

##EQU2## wherein there are m output sites; and

P_o ;

the intensity of light launched into the incident site i;

S_i ;

the light transmittance in the vicinity of the incident site i;

I_k ;

the light transmittance in an internal part of the object; and

S_j ;

the light transmittance in the vicinity of the output site j where j is a number from one to m.