APPARATUS AND METHODS RELATING TO EXPANDED DYNAMIC RANGE IMAGING ENDOSCOPE SYSTEMS

• US 20100004513A1
• Filed: 04/30/2009
• Published: 01/07/2010
• Est. Priority Date: 09/26/2003
• Status: Active Grant

• Current Assignee: Tidal Photonics Incorporated
• Original Assignee: Tidal Photonics Incorporated
• Inventors: Stange, Ulrich, MacKinnon, Nicholas B.
• Granted Patent: US 8,100,826 B2
• Time in Patent Office: Days
• US Class Current: 600/180
• CPC Class Codes: A61B 1/00186 with imaging filters
• CPC Class Codes: A61B 1/05 characterised by the image sensor, e.g. camera, being in the distal end portion
• CPC Class Codes: A61B 1/0638 providing two or more wavelengths
• CPC Class Codes: A61B 1/0655 Control therefor
• CPC Class Codes: A61B 1/227 for ears, i.e. otoscopes
• CPC Class Codes: G01J 1/32 adapted for automatic variation of the measured or reference value regulation of light intensity G05D25/00
• CPC Class Codes: G01J 3/0216 using light concentrators or collectors or condensers
• CPC Class Codes: G01J 3/0229 using masks, aperture plates, spatial light modulators or spatial filters, e.g. reflective filters
• CPC Class Codes: G01J 3/0286 Constructional arrangements for compensating for fluctuations caused by temperature, humidity or pressure, or using cooling or temperature stabilization of parts of the device; Controlling the atmosphere inside a spectrometer, e.g. vacuum
• CPC Class Codes: G01J 3/10 Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01J 3/28 Investigating the spectrum using colour filters G01J3/51
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G01J 3/2823 Imaging spectrometer
• CPC Class Codes: G01N 2021/6471 Special filters, filter wheel
• CPC Class Codes: G01N 2021/6484 Optical fibres
• CPC Class Codes: G01N 21/6456 Spatial resolved fluorescence measurements; Imaging
• CPC Class Codes: G02B 23/2461 Illumination
• CPC Class Codes: G02B 23/2469 using optical fibres
• CPC Class Codes: H04N 23/555 for picking-up images in sites, inaccessible due to their dimensions or hazardous conditions, e.g. endoscopes or borescopes
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means
• CPC Class Codes: H04N 23/84 : for processing colour signals

Abstract

The apparatus and methods herein provide light sources and endoscopy systems that can improve the quality of images and the ability of users to distinguish desired features when viewing tissues by providing methods and apparatus that improve the dynamic range of images from endoscopes, in particular endoscopes that have dynamic range limited because of small image sensors and small pixel electron well capacity, and other optical systems.

Claims

1-32. -32. (canceled)

33. A method of obtaining an image of a target having good dynamic range comprising:

a) emitting illumination light from a tunable light source configured to emit illumination light comprising a variable selected spectral output and a variable wavelength dependent intensity distribution, wherein the light source is configured to independently increase or decrease the variable selected spectral output and the variable wavelength dependent intensity distribution as desired, to illuminate a target;

b) sensing emanating light from the target via an image sensor configured to detect light emanating from a target and transmit an image of the target to a processor; and

,

c) determining whether the emanating light saturates, overexposes or underexposes sensing elements of the image sensor;

d) where the emanating light saturates, overexposes or underexposes sensing elements of the image sensor, selectively adjusting the selected spectral output and wavelength dependent intensity distribution of the illumination light to provide a compensatory illumination light configured to compensate for the oversaturation or underexposure in a specific wavelength distribution in the signal without substantially changing acceptable wavelengths; and

,

e) combining data about the adjusting of the light source with data from the image to provide an enhanced dynamic range compared to the image sensor alone.

34. The method of claim 33 wherein the target is a target tissue and the method is implemented via an endoscope.

35. The method of claim 33 wherein the tunable light source comprises:

a) a source of light,

b) a tunable filter comprising;

a spectrum former able to provide a spectrum from a light beam traveling along a light path from the source of light,

a pixelated spatial light modulator (SLM) located downstream from and optically connected to the spectrum former, the pixelated SLM configured to pass substantially only the selected spectral output and wavelength dependent intensity distribution of the compensatory illumination light to compensate for oversaturation or underexposure in a specific wavelength distribution in the signal without substantially changing acceptable wavelength distributions, the pixelated SLM operably connected to a controller that contains computer-implemented programming that controls an on/off pattern of pixels in the pixelated SLM to pass substantially only the desired wavelength distributions of illumination light.

36. The method of claim 35 wherein the pixelated SLM is a reflective pixelated SLM.

37. The method of claim 36 wherein the reflective surface of the reflective pixelated SLM is configured to provide first and second pixelated SLM regions disposed substantially side-by-side with a light blocking barrier therebetween, and the tunable light source further comprises at least one optical element located and configured to transmit light from the first pixelated SLM region to the second pixelated SLM region.

39. The method of claim 34 wherein the tunable light source comprises at least two tunable filters configured in series to eliminate virtually all unwanted light.

40. The method of claim 34 wherein the image sensor is disposed at the distal end.

41. The method of claim 34 wherein the image sensor is a monochromatic image sensor

42. The method of claim 41 wherein the method further comprises using computer-implemented programming configured to coordinate the light source, image sensor and processor such that the light source provides over time a plurality of different desired wavelength distributions of illumination light each having a selected, substantially pure, variable distribution and intensity, the monochromatic image sensor detects light intensity emanating from the target to provide a detected light intensity for each of the desired wavelength distributions, and the processor associates the detected light intensity for each of the bands with a selected color suitable for display on a display device.

43. The method of claim 34 wherein the compensatory illumination light is attenuated in substantially only a single wavelength band compared to the illumination light.

45. The method of claim 34 wherein the compensatory illumination light is attenuated in a plurality of wavelength bands compared to the illumination light.

46. The method of claim 34 wherein the illumination light comprises at least one band of fluorescence excitation illumination light and at least one long pass filter blocks substantially all of the fluorescence excitation illumination band that reflects back to the image sensor.

48. The method of claim 34 wherein the optical imaging system is a surgical microscope or an otoscope.

49. The method of claim 34 wherein the method further comprises a displaying the high dynamic range image on a display device.

50. The method of claim 34 wherein the body of the endoscope is non-flexible.

51. The method of claim 34 wherein the body of the endoscope is flexible.

55. The method of claim 34 further comprising providing different intensities for at least one wavelength distribution of illumination light by varying the amount of time the different desired wavelength distributions are emitted from the endoscope.

56. The method of claim 34 further comprising providing different intensities for at least one wavelength distribution of illumination light by attenuating the amount of light emitted for the different desired wavelength distributions.

57. The method of claim 34 wherein computer implemented programming selectively also provides a spectral output and a wavelength dependent intensity distribution that substantially mimics a spectral output and a wavelength dependent intensity distribution of output energy for disease treatment.

58. The method of claim 34 wherein the computer implemented programming selectively also provides a spectral output and a wavelength dependent intensity distribution that substantially mimics a spectral output and a wavelength dependent intensity distribution of output energy for photodynamic therapy.

60. The method of claim 34 wherein the computer implemented programming selectively also provides a spectral output and a wavelength dependent intensity distribution that substantially mimics a spectral output and a wavelength dependent intensity distribution of output energy to enhance contrast for detection or discrimination of a desired object in the target.

38. (canceled)

44. (canceled)

47. (canceled)

52-54. -54. (canceled)

58-1. The method of claim 34 wherein the computer implemented programming selectively also provides a spectral output and a wavelength dependent intensity distribution that substantially mimics a spectral output and a wavelength dependent intensity distribution of output energy for disease diagnosis.

61-62. -62. (canceled)