Methods and apparatus for coaxial imaging of multiple wavelengths

• US 10,448,836 B2
• Filed: 04/29/2016
• Issued: 10/22/2019
• Est. Priority Date: 06/05/2012
• Status: Active Grant

• Current Assignee: Hypermed Imaging Incorporated
• Original Assignee: Hypermed Imaging Incorporated
• Inventors: Darty, Mark Anthony
• Primary Examiner(s): Amara, Mohamed K
• Application Number:
  US15/143,399
• Publication Number:
  US 20160345835A1
• Time in Patent Office: 1,271 Days
• CPC Class Codes: A61B 2090/309 using white LEDs
• CPC Class Codes: A61B 2090/3618 with a mirror
• CPC Class Codes: A61B 2560/0425 Ergonomically shaped housings A61B2560/0418 takes precedence
• CPC Class Codes: A61B 2562/0233 Special features of optical sensors or probes classified in A61B5/00
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 5/0075 by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy A61B5/0071 takes precedence
• CPC Class Codes: A61B 5/443 Evaluating skin constituents, e.g. elastin, melanin, water
• CPC Class Codes: A61B 5/447 specially adapted for aiding the prevention of ulcer or pressure sore development, i.e. before the ulcer or sore has developed
• CPC Class Codes: A61B 5/4869 Determining body composition
• CPC Class Codes: A61B 90/30 Devices for illuminating a surgical field, the devices having an interrelation with other surgical devices or with a surgical procedure
• CPC Class Codes: A61B 90/361 Image-producing devices, e.g. surgical cameras
• CPC Class Codes: G01J 2003/1213 Filters in general, e.g. dichroic, band
• CPC Class Codes: G01J 2003/2826 Multispectral imaging, e.g. filter imaging
• CPC Class Codes: G01J 3/0208 using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• CPC Class Codes: G01J 3/021 using plane or convex mirrors, parallel phase plates, or particular reflectors
• CPC Class Codes: G01J 3/0224 using polarising or depolarising elements
• CPC Class Codes: G01J 3/0291 Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements
• CPC Class Codes: G01J 3/10 Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01J 3/12 Generating the spectrum; Monochromators
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G01J 3/2823 : Imaging spectrometer
• CPC Class Codes: G01J 3/36 : Investigating two or more bands of a spectrum by separate detectors
• CPC Class Codes: G01J 3/447 : Polarisation spectrometry
• CPC Class Codes: G01N 2021/4709 : Backscatter
• CPC Class Codes: G01N 21/255 : Details, e.g. use of specially adapted sources, lighting or optical systems
• CPC Class Codes: G01N 21/31 : Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry G01N21/72 takes precedence
• CPC Class Codes: G01N 21/47 : Scattering, i.e. diffuse reflection G01N21/25, G01N21/41 take precedence G01N21/55 takes precedence
• CPC Class Codes: G06F 18/2135 : based on approximation criteria, e.g. principal component analysis
• CPC Class Codes: G06T 2207/10036 : Multispectral image; Hyperspectral image
• CPC Class Codes: G06T 2207/30064 : Lung nodule
• CPC Class Codes: G16H 50/50 : for simulation or modelling of medical disorders

Abstract

A hyperspectral/multispectral imager comprising a housing is provided. At least one light source is attached to the housing. An objective lens, in an optical communication path comprising originating and terminating ends, is further attached to the housing and causes light to (i) be backscattered by the tissue of a subject at the originating end and then (ii) pass through the objective lens to a beam steering element at the terminating end of the communication path inside the housing. The beam steering element has a plurality of operating modes each of which causes the element to be in optical communication with a different optical detector in a plurality of optical detectors offset from the optical communication path. Each respective detector filter in a plurality of detector filters covers a corresponding optical detector in the plurality of optical detectors thereby filtering light received by the corresponding detector from the beam steering element.

Claims

1. A method for forming a hyperspectral/multispectral image of a region of a tissue using an imaging system having a plurality of 2-dimensional optical detectors, the hyperspectral/multispectral image comprising a plurality of sub-images, wherein each respective sub-image in the plurality of sub-images is acquired of the region of the tissue at a corresponding wavelength band in a plurality of wavelength bands, the method comprising:

acquiring, using a first 2-dimensional optical detector in the plurality of 2-dimensional optical detectors of the imaging system, a first sub-image in the plurality of sub-images of the region of the tissue at a first wavelength band in the plurality of wavelength bands at a corresponding first minimum exposure time in a plurality of minimum exposure times; and

acquiring, using a second 2-dimensional optical detector in the plurality of 2-dimensional optical detectors of the imaging system, a second sub-image in the plurality of sub-images of the region of the tissue at a second wavelength band in the plurality of wavelength bands at a corresponding second minimum exposure time, wherein,

the first and second 2-dimensional optical detectors in the plurality of 2-dimensional optical detectors of the imaging system are discrete optical detectors that are independent from each other and spatially separated from each other,

the first and second sub-images are acquired of the same region of the tissue,

the plurality of minimum exposure times is determined by identifying baseline minimum exposure times for resolving the plurality of sub-images and adjusting the baseline minimum exposure times based on the plurality of wavelength bands, wherein

the first minimum exposure time is determined by adjusting, based on the first wavelength band in the plurality of wavelength bands, a first baseline minimum exposure time identified for resolving the first sub-image in the plurality of sub-images, and

the second minimum exposure time is determined by adjusting, based on the second wavelength band in the plurality of wavelength bands, a second baseline minimum exposure time identified for resolving the second sub-image in the plurality of sub-images,

the second wavelength band is different than the first wavelength band in the plurality of wavelength bands, and

the second minimum exposure time is different than the first minimum exposure time.

2. The method of claim 1, further comprising:

acquiring a third sub-image in the plurality of sub-images at a third wavelength band in the plurality of wavelength bands at a corresponding third minimum exposure time in a plurality of minimum exposure times, wherein the third minimum exposure time is different than the first minimum exposure time and the second minimum exposure time.

3. The method of claim 1, wherein the plurality of minimum exposure times is further determined by:

identifying at least one factor affecting one or more minimum baseline exposure times; and

adjusting the baseline minimum exposure times based on the identified factors, thereby determining the plurality of minimum exposure times.

4. The method of claim 3, wherein the at least one factor affecting one or more baseline minimum exposure times includes illumination provided by a device used to acquire the hyperspectral/multispectral image.

5. The method of claim 3, wherein the at least one factor affecting one or more baseline minimum exposure times includes ambient light.

6. The method of claim 3, wherein the at least one factor affecting one or more minimum exposure times includes a concentration of melanin in the tissue.

7. The method of claim 1, wherein the baseline minimum exposure times are based on baseline illumination of the tissue.

8. The method of claim 1, wherein the baseline minimum exposure times are based on the sensitivity of an optical detector acquiring the image.

9. The method of claim 1, wherein the plurality of optical detectors comprises at least four optical detectors.

10. The method of claim 1, wherein each optical detector in the plurality of optical detectors is used for detecting a different wavelength band of light.

11. The method of claim 1, wherein each optical detector in the plurality of optical detectors is covered with a different band-pass filter.

12. A non-transitory computer-readable storage medium storing one or more programs executable by an imaging system with one or more processing units to execute the one or more programs and an optical acquisition system to acquire a hyperspectral/multispectral image of a region of a tissue, the hyperspectral/multispectral image comprising a plurality of sub-images, wherein each respective sub-image in the plurality of sub-images is acquired of the region of the tissue at a corresponding wavelength band in a plurality of wavelength bands, the optical acquisition system comprising a plurality of 2-dimensional optical detectors including a first 2-dimensional optical detector and a second 2-dimensional optical detector, the one or more programs comprising instructions to cause the imaging system to:

acquire a first sub-image in the plurality of sub-images at a first wavelength band in the plurality of wavelength bands at a corresponding first minimum exposure time in a plurality of minimum exposure times using the first 2-dimensional optical detector in the plurality of 2-dimensional optical detectors; and

acquire a second sub-image in the plurality of sub-images at a second wavelength band in the plurality of wavelength bands at a corresponding second minimum exposure time using the second 2-dimensional optical detector in the plurality of 2-dimensional optical detectors, wherein

the first and second 2-dimensional optical detectors in the plurality of 2-dimensional optical detectors of the imaging system are discrete optical detectors that are independent from each other and spatially separated from each other,

the first and second sub-images are acquired of the same region of the tissue,

the plurality of minimum exposure times is determined by identifying baseline minimum exposure times for resolving the plurality of sub-images and adjusting the baseline minimum exposure times based on the plurality of wavelength bands, wherein

the first minimum exposure time is determined by adjusting, based on the first wavelength band in the plurality of wavelength bands, a first baseline minimum exposure time identified for resolving the first sub-image in the plurality of sub-images, and

the second minimum exposure time is determined by adjusting, based on the second wavelength band in the plurality of wavelength bands, a second baseline minimum exposure time identified for resolving the second sub-image in the plurality of sub-images,

the second wavelength band is different than the first wavelength band in the plurality of wavelength bands, and

the second minimum exposure time is different than the first minimum exposure time.

13. The non-transitory computer readable storage medium of claim 12, the one or more programs comprising instructions further cause the imaging system to:

acquire a third sub-image in the plurality of sub-images at a third wavelength band in the plurality of wavelength bands at a corresponding third minimum exposure time, wherein the third minimum exposure time is different than the first minimum exposure time and the second minimum exposure time.

14. The non-transitory computer readable storage medium of claim 12, the one or more programs comprising instructions further cause the imaging system to:

further determine the plurality of minimum exposure times by;

identifying at least one factor affecting one or more minimum baseline exposure times; and

adjusting the baseline exposure times based on the identified factors, thereby determining the plurality of minimum exposure times.

15. The non-transitory computer-readable storage medium of claim 14, wherein the at least one factor affecting one or more baseline minimum exposure times includes illumination provided by a device used to acquire the hyperspectral/multispectral image.

16. The non-transitory computer-readable storage medium of claim 14, wherein the at least one factor affecting one or more baseline minimum exposure times includes ambient light.

17. The non-transitory computer-readable storage medium of claim 14, wherein the at least one factor affecting one or more baseline minimum exposure times includes a concentration of melanin in the tissue.

18. The non-transitory computer-readable storage medium of claim 12, wherein the baseline minimum exposure times are based on baseline illumination of the tissue.

19. The non-transitory computer-readable storage medium of claim 12, wherein the baseline minimum exposure times are based on the sensitivity of an optical detector acquiring the image.

20. The non-transitory computer-readable storage medium of claim 12, wherein the plurality of optical detectors comprises at least four optical detectors.

21. The non-transitory computer-readable storage medium of claim 12, wherein each optical detector in the plurality of optical detectors is used for detecting a different wavelength band of light.

22. The non-transitory computer-readable storage medium of claim 12, wherein each optical detector in the plurality of optical detectors is covered with a different band-pass filter.