Apparatus for tissue examination using bidirectional transirradiation with light

• US 5,787,887 A
• Filed: 05/21/1996
• Issued: 08/04/1998
• Est. Priority Date: 11/24/1993
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Klingenbeck-Regn, Klaus
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): MANTIS MERCADER, ELENI M
• Application Number:
  US08/648,179
• Time in Patent Office: 805 Days
• Field of Search: 128/664, 128/665, 128/633, 356/39, 356/40, 356/41, 356/398, 250/339.01, 250/345, 250/349, 250/341.7
• US Class Current: 600/407
• CPC Class Codes: A61B 5/0091 for mammography
• CPC Class Codes: A61B 5/4312 Breast evaluation or disorder diagnosis A61B5/0091 takes precedence
• CPC Class Codes: G01N 21/4795 spatially resolved investigating of object in scattering medium in vivo A61B

Abstract

An apparatus for examining tissue with light, for identifying inhomogeneities, such as tumors, in the tissue, bidirectionally transirradiates the tissue with light, and detects the light emerging from the tissue in the two directions, thereby providing different images of the tissue with the inhomogeneities therein represented with different contrast, thereby making identification of the inhomogeneity easier.

Claims

1. An apparatus for examining tissue with light, comprising:

means for bidirectionally transirradiating tissue with light from different transirradiation directions;

means for detecting light passing through said tissue in each transirradiation direction upon said light emerging from said tissue,

said means for detecting comprising a single detector, and first and second detector light guide means having respective light entry faces disposed for receiving said light emerging from said tissue in said two directions, and means for alternatingly supplying said light from said respective entry faces to said single detector.

2. An apparatus as claimed in claim 1, wherein said first and second detector light guide means comprise fiber-optic detector light guide means.

3. An apparatus as claimed in claim 1, wherein said first and second light guide means comprise fiber-optic light guide means and wherein said first and second detector light guide means comprise fiber-optic light guide means, each fiber-optic light guide means containing an optical fiber bundle having at least one light guide fiber which conducts light in a first of said transirradiation directions and at least one other light guide fiber which conducts light in a second of said transirradiation directions.

4. An apparatus for examining tissue with light, comprising;

means for bidirectionally transirradiating tissue with light;

scan means for moving said means for bidirectionally transirradiating said tissue with light relative to said tissue at a plurality of different scan positions; and

means for detecting light passing through said tissue in each transirradiation direction upon said light emerging from said tissue.

5. An apparatus as claimed in claim 4, wherein said means for bidirectionally transirradiating tissue comprise means for quasi-simultaneously bidirectionally transirradiating tissue with light.

6. An apparatus as claimed in claim 4, wherein said means bidirectionally transirradiating tissue with light comprise means for simultaneously irradiating tissue in two transirradiation directions.

7. An apparatus as claimed in claim 6, further comprising means for differently modulating the light respectively transmitted in said two transirradiation directions using a first modulation in a first of said two directions and a second modulation in a second of said two directions.

8. An apparatus as claimed in claim 7, wherein said means for differently modulating comprise means for amplitude-modulating the light in said first direction with a modulation frequency and for modulating the light in said second direction with a second modulation frequency.

9. An apparatus as claimed in claim 4, further comprising diaphragm means for alternatingly blocking light from said respective transirradiation directions from reaching said means for detecting.

10. An apparatus as claimed in claim 4, wherein said means for bidirectionally transirradiating tissue with light comprise a first light source and a second light source, wherein said means for detecting comprise a first detector and a second detector, and wherein light in a first of said transirradiation directions emanates from said first light source and is detected by said first detector and light in a second of said transirradiation directions emanates from said second light source and is detected by said second detector.

11. An apparatus as claimed in claim 10 comprising means for simultaneously activating said first light source and said first detector and said second light source and said second detector.

12. An apparatus as claimed in claim 10 further comprising means for simultaneously activating only said first light source and said first detector and subsequently simultaneously activating only said second light source and said second detector.

13. An apparatus as claimed in claim 4, wherein said means for bidirectionally transirradiating tissue comprise a single light source connected to first and second light guides, said light guides having respective light exit faces from which light from said single light source respectively emerges in one of two transirradiation directions.

14. An apparatus as claimed in claim 13, wherein said first and second light guide means comprise fiber-optic light guide means.

15. An apparatus for examining tissue with light, comprising:

means for bidirectionally transirradiating tissue with light from different transirradiation directions;

means for detecting light passing through said tissue in each transirradiation direction upon said light emerging from said tissue and for emitting detector output signals; and

evaluation means, supplied with said detector output signals for analyzing said detector output signals.

16. An apparatus as claimed in claim 15, wherein said bidirectional transirradiation directions have respective optical axes which are offset relative to each other, and wherein said evaluation means comprises means for eliminating said offset.

17. An apparatus as claimed in claim 16 further comprising scan means for moving said means for bidirectionally transirradiating said tissue with light relative to said tissue for bidirectionally transirradiating said tissue with light from a plurality of different scan positions and wherein said means for bidirectionally transirradiating said tissue comprise means for bidirectionally transirradiating said tissue along respective optical axes having an offset which is equal in magnitude and direction for two neighboring scan positions.

18. An apparatus as claimed in claim 16 further comprising scan means for moving said means for bidirectionally transirradiating said tissue with light relative to said tissue for bidirectionally transirradiating said tissue with light from a plurality of different scan positions and wherein said means for bidirectionally transirradiating said tissue comprise means for bidirectionally transirradiating said tissue along respective optical axes having an offset in a scan position which is a whole multiple in terms of magnitude and direction to an offset in a neighboring scan position.

19. An apparatus for examining tissue with light, comprising:

means for bidirectionally transirradiating tissue from different transirradiation directions simultaneously with light, the light from said different directions being of respectively different wavelengths;

means for detecting light passing through said tissue in each transirradiation direction upon said light emerging from said tissue and for emitting a respective detector output signal for light of each of said wavelengths; and

signal processing means, supplied with said detector output signals, for identifying light of each of said different wavelengths in the light detected by said means for detecting.