Polarimetric accessory for colposcope

Patent metadata

Field	Value
Publication number	US-9801536-B2
Application number	US-201314390354-A
Country	US
Kind code	B2
Filing date	Apr 4, 2013
Priority date	Apr 4, 2012
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A polarization-based colposcopy apparatus includes a polarization exchanging beam splitter pair oriented so that s- and p-polarizations are exchanged. An optical flux from a specimen is directed through the pair, and orthogonal components thereof are alternately or selectively coupled to an array detector. The detected images are processed based on image correlations to reveal specimen structures.

First claim

We claim:

1. An apparatus, comprising:
a binocular viewing head that defines a first imaging optical path and a second imaging optical path; and
a polarization exchanging beam splitter pair (PEBSP), the PEBSP including a pair of non-polarizing beam splitters configured so that a first non-polarizing beam splitter is situated to reflect an s-component or a p-component of an incident optical flux and a second non-polarizing beam splitter situated to reflect the s-component and the p-component of the reflected incident optical flux at the first non-polarizing beam splitter as a p-component or an s-component, respectively, at the second non-polarizing beam splitter,
a variable waveplate, and a polarizer situated in the second optical path and configured to selectively direct specimen imaging fluxes corresponding to a first polarization state and a second polarization state to an imaging optical system associated with the second optical path.

2. The apparatus of claim 1 , further comprising a first eyepiece and a second eyepiece situated on the first and second imaging optical paths, respectively, and configured to produce a viewable binocular image.

3. The apparatus of claim 1 , wherein the variable waveplate is a half waveplate that is variable so that the first and second polarization states are linear, orthogonal polarization states.

4. The apparatus of claim 3 , wherein the imaging optical system includes an array detector configured to receive specimen images associated with the first polarization state and second polarization state.

5. The apparatus of claim 4 , further comprising an image processor configured to store the specimen images in a memory.

6. The apparatus of claim 2 , further comprising an optical attenuator situated in the first imaging optical path and configured to compensate insertion loss in the second imaging optical path associated with the PEBSP.

7. The apparatus of claim 6 , wherein the optical attenuator is configured so that that viewable images associated with the first imaging optical path and the second imaging optical path have substantially the same intensity.

8. The apparatus of claim 5 , further comprising an image processor configured to produce a correlation image based on specimen images associated with at least one of the first and second states of polarization.

9. A method, comprising:
obtaining at least a first specimen image and a second specimen image based on an optical flux received from an image through a polarization exchanging beam splitter pair (PEBSP), the PEBSP including a pair of non-polarizing beam splitters configured so that a first non-polarizing beam splitter is situated to reflect an s-component or a p-component of the optical flux and a second non-polarizing beam splitter is situated to reflect the s-component and the p-component of the reflected optical flux at the first non-polarizing beam splitter as a p-component or an s-component, respectively, at the second non-polarizing beam splitter, wherein the first and second specimen images are associated with different states of polarization; and
processing the first image and the second image to identify polarization dependent image portions and produce an associated polarization based images.

10. The method of claim 9 , further comprising displaying at least one of the polarization based images.

11. The method of claim 9 , wherein the first specimen image and the second specimen image are associated with orthogonal linear states of polarization.

12. The method of claim 11 , further comprising selectively detecting imaging optical flux portions associated with the orthogonal linear states of polarization to produce the specimen images.

13. The method of claim 12 , further comprising transmitting the imaging optical flux through a variable retarder and a linear polarizer to an image detector so as to produce the selectively detected imaging optical flux portions.

14. The method of claim 13 , wherein the variable retarder is selectively varied to produce substantially 0 or ½ wave retardance to produce the selectively detected imaging optical flux portions.

15. An apparatus, comprising:
an optical flux source configured to deliver an optical flux to a specimen in a selected state of polarization;
an objective lens configured to form an image of the specimen based on the delivered optical flux;
a polarization exchanging beam splitter pair (PEBSP) configured to receive the optical flux, the PEBSP including a pair of non-polarizing beam splitters configured so that a first non-polarizing beam splitter is situated to reflect an s-component or a p-component of the optical flux and a second non-polarizing beam splitter is situated to reflect the s-component and the p-component of the reflected optical flux at the first non-polarizing beam splitter as a p-component or an s-component, respectively, at the second non-polarizing beam splitter;
a variable waveplate situated to receive the optical flux from the PEBSP and deliver the optical flux to a polarizer;
an image sensor situated to receive the image; and
an image processor configured to stores the received image as a recorded image.

16. The apparatus of claim 15 , wherein the polarizer is a linear polarizer.

17. The apparatus of claim 15 , wherein the variable waveplate has an axis at 45 degrees with respect to the linear polarizer and is switchable to have retardation values of about 0 and about 180 degrees.

18. The apparatus of claim 15 , further comprising a processor configured to produce a correlation image of the specimen based on recorded images associated with at least one of the first and second retardation values of the variable retarder.

19. The apparatus of claim 18 , wherein the processor is configured to produce a correlation image of the specimen based on recorded images associated with the first and second retardation values of the variable retarder.

20. The apparatus of claim 18 , wherein the first and second retardation values differ by about one half wave.

21. The apparatus of claim 18 , wherein the correlation image is based on a Pearson's correlation analysis.

Assignees

• Us Health

Inventors

• Gandjbakhche Amir
• Chernomordik Victor
• Hassan Moinuddin
• Sviridov Alexander
• Ulissi Zachary
• Smith Paul D
• Boccara Albert C

Classifications

• A61B1/000096

  using artificial intelligence · CPC title

• A61B1/303 Primary

  for the vagina, i.e. vaginoscopes · CPC title

• A61B1/0646

  with illumination filters · CPC title

• A61B1/00197

  characterised by multiple eyepieces · CPC title

• A61B1/00193

  adapted for stereoscopic vision · CPC title