Hyperspectral imaging calibration device

• US 6,810,279 B2
• Filed: 11/07/2001
• Issued: 10/26/2004
• Est. Priority Date: 11/07/2000
• Status: Active Grant

• Current Assignee: Hypermed, Inc. (Hypermed Imaging Incorporated)
• Original Assignee: Hypermed, Inc. (Hypermed Imaging Incorporated)
• Inventors: Freeman, Jenny E., Mansfield, James R., Leventon, Michael E., Brand, Derek, Hopmeier, Michael J.
• Primary Examiner(s): IMAM, ALI M
• Application Number:
  US09/986,105
• Publication Number:
  US 20020154300A1
• Time in Patent Office: 1,084 Days
• Field of Search: 600/407-450, 382/103, 382/115, 382/165, 345/39, 345/51, 345/300-334, 345/450-458
• US Class Current: 600/407
• CPC Class Codes: G01J 2003/2866 Markers; Calibrating of scan
• CPC Class Codes: G01J 3/28 Investigating the spectrum using colour filters G01J3/51
• CPC Class Codes: G01J 3/2823 Imaging spectrometer

Abstract

Hyperspectral imaging calibration devices and methods for their use are described that generate images of three dimensional samples. A calibration device may assume the shape of a desired imaging sample such as a body part and may be sterile prior to placement. The calibration device may include openings or may be modified to expose a region of the sample during use. Spectral images, typically obtained at multiple wavelengths, are made of the calibration device. Algorithms are provided that utilize the spectral images of the calibration device to determine the effects of lighting conditions and sample shape on the sample image to form a calibrated image. Calibrated images produced by these devices and methods can provide information, including clinical data that are less sensitive to lighting and sample shape compared to alternative technologies.

Claims

1. A hyperspectral image calibration pad that has at least one surface exterior to a body part with the following optical properties:

a. at least 95% opaque to electromagnetic radiation over a predetermined wavelength range of at least 50 nanometers;

b. a predetermined reflectance of at least 1 percent to wavelengths of light over said wavelength range;

c. a reflectance value for at least a first wavelength within said 50 nanometer wavelength range that varies less than 10% over a desirable image region; and

d. a reflectance value for at least a second wavelength within said 50 nanometer wavelength range that varies less than 10% over a desirable image region.

2. The calibration pad of claim 1 wherein the pad is form fitting to a sample to assume the shape of that sample.

3. The calibration pad of claim 1 wherein the pad conforms to said at least one surface with minimal deformation that would effect imaging.

4. The calibration pad of claim 1 wherein the pad is form fitting to approximate surface contours of at least one surface to be imaged.

5. The calibration pad of claim 1 prepared by a process comprising:

a. bathing the pad in a solution; and

b. packaging the pad from step a.

6. The calibration pad of claim 1 comprising a hydrogel pack.

7. The calibration pad of claim 1 wherein the at least 50 nanometer wavelength range is at least 100 nanometers.

8. The calibration pad of claim 1 wherein the at least 50 nanometer wavelength range is at least 200 nanometers.

9. The calibration pad of claim 1 wherein the at least 50 nanometer wavelength range is at least 400 nanometers.

10. The calibration pad of claim 1 wherein the at least 50 nanometer wavelength range is at least 700 nanometers.

11. The calibration pad of claim 1 wherein the predetermined reflectance is at least 5 percent.

12. The calibration pad of claim 1 wherein the predetermined reflectance is at least 10 percent.

13. The calibration pad of claim 1 wherein the predetermined reflectance is at least 25 percent.

14. The calibration pad of claim 1 wherein reflectance properties of the exterior surface change as a function of temperature.

15. The calibration pad of claim 1 wherein reflectance properties of the exterior surface change as a function of humidity.

16. The calibration pad of claim 1 wherein the pad is polarized to electromagnetic radiation over said predetermined wavelength range.

17. The calibration pad of claim 1 wherein the pad becomes transparent or translucent upon contact with an aqueous solution.

18. The calibration pad of claim 1 wherein the pad becomes opaque upon contact with an aqueous solution.

19. The calibration pad of claim 1 further comprising one or more fiducial markers for spatial registration useful for imaging.

20. The calibration pad of claim 1 further comprising one or more fiducial markers with a predetermined geometric relationship for spatial registration between image acquisitions.

21. The calibration pad of claim 1 further comprising one or more transferable fiducial marks that are transferred from the calibration pad onto a sample where they remain following removal of the calibration pad.

22. The calibration pad of claim 21 wherein the one or more transferable fiducial marks comprise an ink.

23. The calibration pad of claim 22 wherein the ink is a non-indelible ink.

24. The calibration pad of claim 1 comprising one or more markings on the exterior surface, wherein at least one of the one or more markings has a defined size and shape that allows for the determination of at least one spatial dimension of an acquired hyperspectral image.

25. The calibration pad of claim 24 wherein the one or more markings on the calibration pad provide a contour suitable for three dimensional stereoscopic referencing.

26. The calibration pad of claim 1 further comprising a removable interior section, which, upon removal provides optical access to a sample surface.

27. The calibration pad of claim 1 further comprising a portion that can become transparent to wavelengths of interest.

28. The calibration pad of claim 1 further comprising a portion that can become opaque to wavelengths of interest.

29. The calibration pad of claim 1 wherein the pad is a two dimensional grid of strips that provide geometric holes to image a subject.

30. The calibration pad of claim 29 wherein the geometric holes are circular or rectangular.

31. The calibration pad of claim 1 wherein the pad is formed on a sample by spraying.

32. The calibration pad of claim 31 wherein a sheet is placed over the sample before formation of the pad by spraying.

33. The calibration pad of claim 1 wherein the pad is sterile.

34. The calibration pad of claim 1 wherein the wavelength range is selected from the group consisting of 400 to 700 nanometers, 400 to 1100 nanometers, and 400 to 1800 nanometers.