Scanning module for imaging through scattering media

• US 6,332,093 B1
• Filed: 08/06/1998
• Issued: 12/18/2001
• Est. Priority Date: 08/06/1998
• Status: Expired due to Fees

• Current Assignee: Softscan Healthcare Group Limited
• Original Assignee: Art Recherches et Technologies Avancees Incorporated /ART Advanced Research Technologies Incorporated
• Inventors: Painchaud, Yves, Mailloux, Alain
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): SHAW, SHAWNA JEANNINE
• Application Number:
  US09/129,886
• Time in Patent Office: 1,230 Days
• Field of Search: 600/473, 600/476, 600/310, 356/337, 356/338, 356/342, 356/345, 250/339.11
• US Class Current: 600/476
• 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

A scanning module for imaging through scattering media is provided. The scanning module image through scattering media while alleviating adverse effects of the weak transmission through highly scattering media. The injection of photons is optimized so that the overall transmission is increased compared to the conventional art. Cross-talk effects in a multi-port geometry are eliminated thereby increasing parallelism.

Claims

1. An apparatus for imaging through scattering media, comprising:

an ultra short light pulse source disposed on a first side of said scattering media;

at least one detector disposed on a second side of said scattering media; and

a reflector disposed adjacent to said first side of said scattering media to reflect back into said scattering media part of photons injected into said scattering media from said ultra short light pulse source;

said part of photons being reflected back to said first side of said scattering media by scattering;

wherein said ultra short light pulse is transmitted into said scattering media through a hole in said reflector, and said at least one detector receives light transmitted through said scattering media from said source.

2. An apparatus for imaging through scattering media as recited in claim 1, further comprising an optical fiber for carrying said ultra short light pulse from said source to said first side of said scattering media through said reflector.

3. An apparatus for imaging through scattering media as recited in claim 2, wherein said source moves in a scanning direction perpendicular to said first side of said scattering media.

4. An apparatus for imaging through scattering media as recited in claim 3, wherein said detector moves in a direction parallel to said scanning direction.

5. An apparatus for imaging through scattering media as recited in claim 1, further comprising a transparent medium disposed on said first side of said scattering media to maintain a shape of said scattering media.

6. An apparatus for imaging through scattering media as recited in claim 1, wherein said source moves in a scanning direction perpendicular to said first side of said scattering media.

7. An apparatus for imaging through scattering media as recited in claim 6, wherein said detector moves in a direction parallel to said scanning direction.

8. An apparatus for imaging through scattering media as recited in claim 1, further comprising a circular re-injection reflector disposed around said detector to increase an effective surface of said detector.

9. An apparatus for imaging through scattering media as recited in claim 1, further comprising a transparent medium disposed on said second side of said scattering media to maintain a shape of said scattering media.

10. An apparatus for imaging through scattering media, comprising:

an ultra short light pulse source disposed on a first side of said scattering media;

at least one detector disposed on a second side of said scattering media; and

a circular re-injection reflector disposed around said at least one detector to increase an effective surface of said at least one detector.

11. An apparatus for imaging through scattering media as recited in claim 10, further comprising an optical fiber for carrying said ultra short light pulse from said source to said first side of said scattering media.

12. An apparatus for imaging through scattering media as recited in claim 11, wherein said source moves in a scanning direction perpendicular to said first side of said scattering media.

13. An apparatus for imaging through scattering media as recited in claim 12, wherein said detector moves in a direction parallel to said scanning direction.

14. An apparatus for imaging through scattering media as recited in claim 10, further comprising a transparent medium disposed on said first side of said scattering media to maintain a shape of said scattering media.

15. An apparatus for imaging through scattering media as recited in claim 10, wherein said source moves in a scanning direction perpendicular to said first side of said scattering media.

16. An apparatus for imaging through scattering media as recited in claim 15, wherein said detector moves in a direction parallel to said scanning direction.

17. An apparatus for imaging through scattering media as recited in claim 10, further comprising a transparent medium disposed on said second side of said scattering media to maintain a shape of said scattering media.

18. An apparatus for imaging through scattering media, comprising:

an ultra short light pulse source disposed on a first side of said scattering media;

at least two detectors disposed on a second side of said scattering media;

a divider which splits said ultra short light pulse into at least two equal optical pulses;

at least two first optical fibers, disposed between said divider and said scattering media, said at least two optical fibers receiving and transmitting said at least two optical pulses to said scattering media; and

at least two second optical fiber s disposed on said second side of said scattering media for transmitting said received light to said at least two detectors, wherein any cross-talk arrives at said at least two detectors before or after two useful signals from said two first optical fibers.

19. An apparatus for imaging through scattering media as recited in claim 18, wherein a length of a first one of said first optical fibers plus a length of a first one of said second optical fibers is equal to a length of a second one of said first optical fibers plus a length of a second one of said second optical fibers.

20. An apparatus for imaging through scattering media as recited in claim 19, wherein said at least two first optical fibers are of unequal length, and said at least two second optical fibers are of unequal length.

21. An apparatus for imaging through scattering media as recited in claim 18, wherein a repetition rate of said ultra short pulses is small so that time intervals between said ultra short pulses are large enough to accommodate delayed cross-talk.

22. An apparatus for imaging through scattering media as recited in claim 18, wherein a first total pathlength comprising a first one of said at least two first optical fibers and a first one of said at least two second optical fibers is equal to a second total pathlength comprising a second one of said at least two first optical fibers and a second one of said at least two second optical fibers for useful signals.

23. An apparatus for imaging through scattering media as recited in claim 22, wherein cross-talk arrives at said at least to detectors before or after two useful signals from said two first optical fibers.

24. An apparatus for imaging through scattering media, comprising:

an ultra short light pulse source disposed on a first side of said scattering media;

at least two detectors disposed on a second side of said scattering media, said second side being opposite said first side;

a reflector disposed adjacent to said first side of said scattering media to reflect back into said scattering media part of photons injected into said scattering media from said ultra short light pulse source;

said part of photons being reflected back to said first side of said scattering media by scattering;

wherein said ultra short light pulse is transmitted into said scattering media through a hole in said reflector, and said at least two detectors receive light transmitted through said scattering media from said source;

an optical fiber for carrying said ultra short light pulse from said source to said first side of said scattering media;

a transparent medium disposed on said first side of said scattering media to maintain a shape of said scattering media, and a transparent medium disposed on said second side of said scattering media to maintain a shape of said scattering media; and

a circular re-injection reflector disposed around said detector to increase an effective surface of said at least two detectors;

a divider which splits said ultra short light pulse into at least two equal optical pulses;

at least two first optical fibers, disposed between said divider and said scattering media, said at least two optical fibers receiving and transmitting said at least two optical pulses to said scattering media; and

at least two second optical fibers disposed on said second side of said scattering media for transmitting said received light to said at least two detectors;

wherein said source moves in a scanning direction perpendicular to said first side of said scattering media, and said detector moves in a direction parallel to said scanning direction

wherein a length of a first one of said first optical fibers plus a length of a first one of said second optical fibers is equal to a length of a second one of said first optical fibers plus a length of a second one of said second optical fibers, and

wherein said at least two first optical fibers are of unequal length, and said at least two second optical fibers are of unequal length.