IMAGING SYSTEM FOR COMBINED FULL-COLOR REFLECTANCE AND NEAR-INFRARED IMAGING

• US 20110063427A1
• Filed: 03/18/2009
• Published: 03/17/2011
• Est. Priority Date: 03/18/2008
• Status: Active Grant

• Current Assignee: Stryker Corporation
• Original Assignee: Novadaq Technologies, Inc. (Stryker Corporation)
• Inventors: Fengler, John, Cottle, Paul, Westwick, Paul, Bailey, Arthur E.
• Granted Patent: US 9,173,554 B2
• Time in Patent Office: Days
• US Class Current: 348/65
• CPC Class Codes: A61B 1/00009 of image signals during a use of endoscope
• CPC Class Codes: A61B 1/00043 provided with output arrangements
• CPC Class Codes: A61B 1/00045 Display arrangement
• CPC Class Codes: A61B 1/0005 combining images e.g. side-by-side, superimposed or tiled
• CPC Class Codes: A61B 1/00163 Optical arrangements A61B1/002, A61B1/06 take precedence
• CPC Class Codes: A61B 1/00186 with imaging filters
• CPC Class Codes: A61B 1/04 combined with photographic or television appliances
• CPC Class Codes: A61B 1/042 characterised by a proximal camera, e.g. a CCD camera
• CPC Class Codes: A61B 1/043 for fluorescence imaging
• CPC Class Codes: A61B 1/045 Control thereof
• CPC Class Codes: A61B 1/046 for infrared imaging
• CPC Class Codes: A61B 1/06 with illuminating arrangements
• CPC Class Codes: A61B 1/0638 providing two or more wavelengths
• CPC Class Codes: A61B 1/0646 with illumination filters
• CPC Class Codes: A61B 1/0655 Control therefor
• CPC Class Codes: A61B 1/0669 at proximal end of an endoscope
• CPC Class Codes: A61B 5/0062 Arrangements for scanning
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• 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 5/0086 using infrared radiation
• CPC Class Codes: A61B 5/418 : lymph vessels, ducts or nodes
• CPC Class Codes: A61B 5/7425 : Displaying combinations of multiple images regardless of image source, e.g. displaying a reference anatomical image with a live image geometric transforms for image registration G06T3/14; enhancement using image fusion G06T5/50; algorithms for registration of images G06T7/30
• CPC Class Codes: G02B 27/1013 : for colour or multispectral image sensors, e.g. splitting an image into monochromatic image components on respective sensors spectral imaging systems G01J
• CPC Class Codes: G06T 2207/10048 : Infrared image
• CPC Class Codes: H04N 23/11 : for generating image signals from visible and infrared light wavelengths
• CPC Class Codes: H04N 23/21 : from near infrared [NIR] radiation
• CPC Class Codes: H04N 5/33 : Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

An imaging system for acquisition of NIR and full-color images includes a light source providing visible light and NIR light to an area under observation, such as living tissue, a camera having one or more image sensors configured to separately detect blue reflectance light, green reflectance light, and combined red reflectance light/detected NIR light returned from the area under observation. A controller in signal communication with the light source and the camera is configured to control the light source to continuously illuminate area under observation with temporally continuous blue/green illumination light and with red illumination light and NIR excitation light. At least one of the red illumination light and NIR excitation light are switched on and off periodically in synchronism with the acquisition of red and NIR light images in the camera.

Claims

1. A method for acquisition of NIR and full-color images, comprising the steps of:

continuously illuminating an area under observation with blue/green light,

illuminating the area under observation with red light and NIR light, wherein at least one of the red light and NIR light are switched on and off periodically,

directing blue and green reflectance light and combined red reflectance light/detected NIR light to one or more sensors configured to separately detect the blue reflectance light, the green reflectance light, and the red reflectance light/detected NIR light, wherein the red reflectance light/detected NIR light is detected in synchronism with the switched red light and NIR light,

determining from image signals of the combined red reflectance light/detected NIR light separately the red reflectance light spectral component and the detected NIR light spectral component,

displaying a full-color image of the area under observation from the blue and green reflectance light and the separately determined red light spectral component, and

displaying an NIR image from the detected NIR light spectral component.

2. The method of claim 1, wherein the area under observation is alternatingly illuminated with red light and NIR light.

3. The method of claim 2, wherein a time duration of red light illumination is different from a time duration of NIR light illumination.

4. The method of claim 3, wherein the time duration of red light illumination is longer than the time duration of NIR light illumination.

5. The method of claim 2, wherein a time duration of red light illumination is substantially identical to a time duration of NIR light illumination.

6. The method of claim 1, wherein the area under observation is continuously illuminated with red light and periodically illuminated with NIR light.

7. The method of claim 1, wherein the area under observation is continuously illuminated with NIR light and periodically illuminated with red light.

8. The method of claim 1, wherein the red light or NIR light, or both, are switched at video rates.

9. The method of claim 2, wherein image fields lacking the red reflectance light spectral component or the detected NIR light spectral component are interpolated from temporally adjacent image fields that include a corresponding red reflectance light spectral component or detected NIR light spectral component.

10. The method of claim 7, wherein the NIR light spectral component obtained in the absence of red light illumination is subtracted from the combined red reflectance light/detected NIR light to obtain the separate red reflectance light spectral component.

11. The method of claim 1, wherein spatial information of the area under observation is primarily derived from the blue reflectance light and the green reflectance light.

12. The method of claim 1, wherein the detected NIR light is fluorescence light.

13. An imaging system for acquisition of NIR images and full-color images comprising:

a light source providing visible light and NIR light to an area under observation,

a camera having one or more image sensors configured to separately detect blue reflectance light, green reflectance light, and combined red reflectance light/detected NIR light returned from the area under observation,

a controller in signal communication with the light source and the camera for

continuously illuminating area under observation with blue/green light,

illuminating the area under observation with red light and NIR light, wherein at least one of the red light and NIR light are switched on and off periodically, and

determining from the combined red reflectance light/detected NIR light separately the red reflectance light spectral component and the detected NIR light spectral component in synchronism with the switched red and NIR light, and

a display receiving image signals corresponding to the blue reflectance light, the green reflectance light, and the separately determined red reflectance light spectral component and rendering therefrom a full-color reflectance image of the area under observation, the display further receiving the separately determined NIR fluorescence light spectral component and rendering therefrom an NIR image of the area under observation.

14. The imaging system of claim 13, wherein the area under observation is alternatingly illuminated by the light source with red light and NIR light.

15. The imaging system of claim 13, wherein the light source comprises

an illuminator emitting a substantially constant intensity of visible light and NIR light over a continuous spectral range, and

a plurality of filters disposed between the illuminator and the area under observation for transmitting temporally continuous blue/green light and temporally discontinuous red light and discontinuous NIR light.

16. The imaging system of claim 13, wherein the light source comprises

an illuminator emitting a substantially constant intensity of visible light and NIR light over a continuous spectral range,

first dichroic means for separating the visible light and NIR light into blue/green and red light and NIR light,

shutter means for transforming the separated red light and NIR light into temporally discontinuous red light and discontinuous NIR light, and

second dichroic means for combining the blue/green light, the temporally discontinuous red light and the temporally discontinuous NIR light for transmission to the area under observation.

17. The imaging system of claim 13, wherein the light source comprises

a first illuminator emitting a substantially constant intensity of green and blue light,

a second illuminator producing switched red light,

a third illuminator producing switched NIR light, and

dichroic means for combining the switched red light and the switched NIR light with the green and blue light for transmission to the area under observation.

18. The imaging system of claim 17, wherein the switched red light and the NIR light are produced by interrupting a continuous intensity light beam of the red light and the NIR light by a shutter or chopper.

19. The imaging system of claim 17, wherein the switched red light and the NIR light are produced by electrically switching the second illuminator and the third illuminator on and off.

20. The imaging system of claim 13, wherein the image sensors employ an interlaced scan.

21. The imaging system of claim 13, wherein the image sensors employ a progressive scan.

22. The imaging system of claim 13, further comprising a dichroic prism assembly spectrally separating the blue reflectance light, the green reflectance light and the combined red reflectance light/detected NIR light returned from the area under observation and directing the separated light to different exit faces of the dichroic prism assembly, wherein the one or more image sensors comprise three image sensors, each mounted on a different exit face.

23. The imaging system of claim 13, wherein the one or more image sensors comprise a single image sensor having pixels, each pixel responsive to one of the blue reflectance light, the green reflectance light and the combined red reflectance light/detected NIR light returned from the area under observation.

24. The imaging system of claim 23, wherein the single image sensor comprises a mosaic blue/green/red-NIR filter array disposed before the sensor pixels.

25. The imaging system of claim 13, wherein the one or more image sensors comprise a single image sensor having a plurality of stacked layers, each layer having pixels responsive to one of the blue reflectance light, the green reflectance light and the combined red reflectance light/detected NIR light returned from the area under observation.

26. The imaging system of claim 13, wherein the imaging system is configured as an endoscope.

27. The imaging system of claim 13, wherein the detected NIR light is fluorescence light.