SYSTEMS AND METHODS FOR RAPID WIDE FIELD ILLUMINATION SCANNING FOR IN VIVO SMALL ANIMAL FLUORESCENCE TOMOGRAPHIC IMAGING

• US 20190021602A1
• Filed: 07/19/2017
• Published: 01/24/2019
• Est. Priority Date: 07/19/2017
• Status: Active Grant

• Current Assignee: Revvity Health Sciences Incorporated (Revvity, Inc.)
• Original Assignee: Perkinelmer Health Sciences Incorporated (Perkinelmer Incorporated)
• Inventors: Hurley, William, Behrooz, Ali, Meltzer, Michael, Wilson, Andrew
• Granted Patent: US 11,141,064 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 2503/40 Animals
• CPC Class Codes: A61B 5/0062 Arrangements for scanning
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/0073 by tomography, i.e. reconstruction of 3D images from 2D projections A61B5/0066 takes precedence
• CPC Class Codes: G01N 21/4795 spatially resolved investigating of object in scattering medium in vivo A61B
• CPC Class Codes: G01N 21/6456 Spatial resolved fluorescence measurements; Imaging
• CPC Class Codes: G01N 2201/10 Scanning
• CPC Class Codes: G02B 19/0014 at least one surface having optical power
• CPC Class Codes: G02B 19/0052 the light source comprising a laser diode coupling into light guides using intermediate optical elements G02B6/4204; semiconductor lasers having optical devices external to the laser cavity H01S5/005
• CPC Class Codes: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129
• CPC Class Codes: G02B 26/105 with one or more pivoting mirrors or galvano-mirrors G02B26/101 takes precedence
• CPC Class Codes: G06T 11/003 Reconstruction from projections, e.g. tomography
• CPC Class Codes: G06T 7/0012 Biomedical image inspection

Abstract

Presented herein are systems and methods for tomographic imaging that provide for rapid illumination of multiple excitation locations across a large field of view by one or more beams of excitation light from one or more excitation sources. The approaches described herein utilize a galvanometer optical scanner to scan a beam of excitation light through a plurality of locations across a scan region corresponding to the field of view to be imaged. In certain embodiments, the systems and methods described herein utilize beams of excitation light with specifically tailored shapes to maintain small spot sizes across the large scan region. The ability to scan over a large region while still maintaining small spot sizes provided by the approaches described herein allows for accurate, high-resolution tomographic imaging of large or multiple subjects, thereby expanding the capabilities of tomographic imaging systems.

Claims

1. A system for fast scanning of excitation light over a wide field of view for tomographic imaging of one or more subjects positioned across an object plane, the system comprising:

(a) an excitation source operable to emit a beam of excitation light, wherein the excitation source is aligned to direct the beam of excitation light along an optical path from an output of the excitation source to a galvanometer optical scanner comprising one or more rotating galvanometer mirrors;

(b) the galvanometer optical scanner, wherein the galvanometer optical scanner is aligned and operable to direct the beam of excitation light to a plurality of locations within a scan region of the object plane via reflection by the one or more rotating galvanometer mirrors, such that as the one or more galvanometer mirrors is/are rotated, the beam of excitation light is scanned across the scan region, thereby providing for illumination of the one or more subjects positioned across the object plane;

(c) one or more detectors aligned and operable to detect fluorescent light emitted from one or more fluorescent species within the one or more subjects as a result of excitation by the excitation light;

(d) a processor; and

(e) a memory having instructions stored thereon, wherein the instructions, when executed by the processor cause the processor to;

receive and/or access data corresponding to the detected fluorescent light; and

obtain one or more tomographic images of the one or more subjects using the data corresponding to the detected fluorescent light.

2. The system of claim 1, wherein the galvanometer optical scanner is positioned a specific distance, measured along a minimal length optical path from the galvanometer optical scanner to a location within the scan region, to produce a scan region of a desired size, based on one or more maximal rotational angles of the one or more galvanometer mirrors.

3. The system of claim 2, wherein the desired size of the scan region along a first dimension and/or a second dimension is at least 100 mm.

5. The system of claim 1, wherein a minimal distance along a minimal length optical path from the galvanometer optical scanner to a location within the scan region is from 150 to 250 mm.

6. The system of claim 1, wherein the excitation source is operable to emit the beam of excitation light from its output as a focused beam that converges as it travels (i) towards the galvanometer optical scanner and (ii) from the galvanometer optical scanner to the object plane.

7. The system of claim 6, wherein the focused beam of excitation light emitted from the output of the excitation source has a spot size less than or approximately equal to 1 mm at all locations within the scan region.

8. The system of claim 6, wherein the focused beam of excitation light emitted from the output of the excitation source has a half-angle divergence, φ

, such that

9. The system of claim 7, wherein a half-angle divergence of the focused beam of excitation light emitted from the output of the excitation source is less than or equal to 25 mrad.

14. The system of claim 1, wherein the system comprises a beam shaping optic positioned in the optical path from the output of the excitation source to the galvanometer optical scanner, wherein the beam shaping optic is at least one of:

(A) a focusing optic, wherein the focusing optic is aligned such that after passing through the focusing optic, the beam of excitation light converges as it travels (i) towards the galvanometer optical scanner and (ii) from the galvanometer optical scanner to the object plane; and

(B) a collimating optic, wherein the collimating optic is aligned such that after passing through the collimating optic, the beam of excitation light diverges as it travels (i) towards the galvanometer optical scanner and (ii) from the galvanometer optical scanner to the object plane.

15. The system of claim 14, wherein the beam shaping optic is the focusing optic.

16. The system of claim 15, wherein the focusing optic is positioned such that a spot size of the beam of excitation light is less than or approximately equal to 1 mm in diameter at all locations within the scan region.

17. The system of claim 15, wherein a half-angle divergence, φ

, of the beam of excitation light after passing through the focusing optic is such that

18. The system of claim 15, wherein a half-angle divergence of the beam of excitation light after passing through the focusing optic is less than or equal to 25 mrad.

23. The system of claim 1, wherein a power of the excitation source is greater than or approximately equal to 100 mW.

24. The system of claim 1, wherein the excitation source is a fiber coupled laser or a fiber laser and the output of the excitation source from which the beam of excitation light is emitted is a distal end an optical fiber of the fiber coupled laser or fiber laser.

25. The system of claim 24, wherein a core diameter of the optical fiber of the fiber coupled laser or fiber laser is from 5 μ

m to 400 μ

m.

26. The system of claim 24, wherein a numerical aperture (NA) of the optical fiber is from 0.1 to 0.3.

30. The system of claim 1, wherein the one or more detectors are aligned and operable to detect the fluorescent light emitted from the fluorescent species in a transillumination geometry, wherein the beam of excitation light is directed towards the object plane from a first side of the object plane and the one or more detectors are aligned and operable to detect fluorescent light emitted in directions outwards from an opposite second side of the object plane.

36. The system of claim 1, wherein:

the one or more detectors are aligned and operable to detect excitation light transmitted through or reflected from the one or more subjects, and

the instructions cause the processor to;

receive and/or access data corresponding to the detected excitation light; and

obtain, one or more tomographic images of the one or more subjects using the data corresponding to the detected excitation light and the data corresponding to the detected fluorescent light.

37. The system of claim 1, wherein:

the galvanometer optical scanner is aligned and operable to scan the beam of excitation light across the scan region by directing the beam of excitation light to a plurality of discrete excitation locations within the scan region, wherein, for each discrete excitation location, a given subject of the one or more subjects that is positioned in the path of the beam of excitation light directed towards the discrete excitation location is illuminated by the beam of excitation light at a corresponding illumination location on a surface of the subject, such that the beam of excitation light is incident on the surface of the given subject at the corresponding illumination location and diffuses within the subject, thereby providing for excitation of a fluorescent species within the given subject,

the one or more detectors are aligned and operable to detect, for each discrete excitation location, a corresponding fluorescence emission image representing detected fluorescent light emitted by the fluorescent species within a given subject that is positioned in the path of the beam of excitation light directed to the discrete excitation location, thereby providing for detection of a plurality of fluorescence emission images, each corresponding to a discrete excitation location, and

the instructions cause the processor to;

receive and/or access data corresponding to the detected fluorescent light, the data corresponding to the detected fluorescent light comprising the plurality of fluorescence emission images; and

obtain the one or more tomographic images of the one or more subjects using the plurality of fluorescence emission images.

38. The system of claim 37, wherein:

the one or more detectors are aligned and operable to detect, for each discrete excitation location, a corresponding excitation image representing excitation light transmitted through or reflected by the given subject when the beam of excitation light incident on the surface of the given subject at the corresponding illumination location, such that a plurality of excitation images, each corresponding to a discrete excitation location, are detected, and

the instructions cause the processor to;

receive and/or access data corresponding to the detected excitation light, the data corresponding to the detected excitation light comprising the plurality of excitation images; and

obtain the one or more tomographic images of the one or more subjects using the plurality of fluorescence emission images and the plurality of excitation images.

39. The system of claim 1, wherein:

the galvanometer optical scanner is operable to scan the beam of excitation light across the scan region by directing it to a plurality of discrete excitation locations within the scan region, wherein;

the discrete excitation locations are arranged in sets, each set comprising a plurality of discrete excitation locations, each discrete excitation location of a given set corresponding to a different subject of the one or more subjects,

the galvanometer optical scanner is operable to scan the beam of excitation light one set at a time, directing the beam of excitation light to each discrete excitation location within a given set before proceeding on to a next set, and

the galvanometer optical scanner is operable to scan the beam of excitation light through all the discrete excitation locations of given set within a time corresponding to an exposure window of the one or more detectors, and

the one or more detectors are aligned and operable to detect, for each set of discrete excitation locations, a corresponding fluorescence emission image representing detected fluorescent light emitted during the exposure window of the one or more detectors as a result of excitation of the one or more fluorescent species within the one or more subjects by excitation light directed to each excitation location within a given set.

40. The system of claim 39, wherein:

the data corresponding to the detected fluorescent light comprises, for each set of discrete excitation locations, the corresponding fluorescence emission image, and

the instructions cause the processor to obtain a tomographic image for each subject of the one or more subjects using the fluorescence emission images.

41. The system of claim 40, wherein the instructions cause the processor to, for each subject of the one or more subjects:

for each fluorescence emission image corresponding to a set of discrete excitation locations, thereby determining a single subject fluorescence emission image associated with the subject and corresponding to the set of discrete excitation locations, determine a portion of the fluorescence emission image associated with the subject, thereby determining a plurality of single subject fluorescence emission images associated with the subject, wherein each single subject fluorescence image corresponds to a set of discrete excitation locations; and

obtain a tomographic image of the subject using the plurality of single subject fluorescence emission images associated with the subject.

42. The system of claim 39, wherein:

the one or more detectors are aligned and operable to detect, for each set of discrete excitation locations, a corresponding excitation image representing excitation light transmitted through or reflected by the one or more subjects detected during the exposure window of the one or more detectors as a result of illumination of the one or more subjects by the beam of excitation light directed to each excitation location within a given set, and

the instructions cause the processor to;

receive and/or access data corresponding to the detected excitation light, the data corresponding to the detected excitation light comprising, for each set of discrete excitation locations, the corresponding excitation image; and

obtain a tomographic image for each subject of the one or more subjects using the detected fluorescence emission images and the detected excitation images.

43. The system of claim 42, wherein the instructions cause the processor to, for each subject of the one or more subjects:

for each fluorescence emission image corresponding to a set of discrete excitation locations, determine a portion of the fluorescence emission image associated with the subject, thereby determining a single subject fluorescence emission image associated with the subject and corresponding to the set of discrete excitation locations, thereby determining a plurality of single subject fluorescence emission images associated with the subject, wherein each single subject fluorescence emission image corresponds to a set of discrete excitation locations; and

for each excitation image corresponding to a set of discrete excitation locations, determine a portion of the excitation image associated with the subject, thereby determining a single subject excitation image associated with the subject and corresponding to the set of discrete excitation locations, thereby determining a plurality of single subject excitation images associated with the subject, wherein each single subject excitation image corresponds to a set of discrete excitation locations; and

obtain a tomographic image of the subject using the plurality of single subject fluorescence emission images associated with the subject and the plurality of single subject excitation images associated with the subject.

4. (canceled)

10-13. -13. (canceled)

19-22. -22. (canceled)

27-29. -29. (canceled)

31-35. -35. (canceled)

44. A system for fast scanning of excitation light from a plurality of excitation sources over a wide field of view for tomographic imaging of one or more subjects positioned across an object plane, the system comprising:

(a) a plurality of excitation sources, wherein;

each excitation source is operable to emit a respective beam of excitation light,

a first excitation source is aligned to direct its respective beam of excitation light along a first optical path from an output of the first excitation source to a galvanometer optical scanner comprising one or more rotating galvanometer mirrors, and

each excitation source other than the first excitation source is aligned to direct its respective beam of excitation light along a respective optical path from its output to the galvanometer optical scanner at a corresponding offset angle with respect to the first optical path;

(b) the galvanometer optical scanner, wherein the galvanometer optical scanner is aligned and operable to, for each excitation source, direct the respective beam of excitation light emitted by the excitation source to a respective plurality of locations within a respective scan region of the object plane via reflection by the one or more rotating galvanometer mirrors, such that as the one or more galvanometer mirrors is/are rotated, the respective beam of excitation light emitted by the excitation source is scanned across the respective scan region, thereby providing for illumination of the one or more subjects positioned across the object plane;

(c) one or more detectors aligned and operable to detect fluorescence light emitted from one or more fluorescent species within the one or more subjects as a result of excitation by the excitation light from at least one of the plurality of excitation sources;

(d) a processor; and

(e) a memory having instructions stored thereon, wherein the instructions, when executed by the processor cause the processor to;

receive and/or access data corresponding to the detected fluorescent light; and

obtain one or more tomographic images of the one or more subjects using the data corresponding to the detected fluorescent light.

45. The system of claim 44, wherein each excitation source emits excitation light having a distinct excitation wavelength within an excitation band of a corresponding fluorescent species within the one or more subjects.

46. The system of claim 44, wherein the one or more detectors are aligned and operable to detect fluorescence light emitted from the one or more fluorescent species within the one or more subjects as a result of excitation by the excitation light from each of two or more excitation sources of the plurality of excitation sources.

47. The system of claim 44, wherein:

the data corresponding to the detected fluorescent light comprises, for each of two or more excitation sources of the plurality of excitation sources, a set of associated fluorescence emission signals detected following excitation by excitation light directed towards each of a plurality of excitation locations across the respective scan region of the excitation source, and

the instructions cause the processor to, for each of the two or more excitation sources, obtain a respective set of one or more tomographic images of the one or more subjects using the associated fluorescence emission signals, thereby obtaining a set of one or more tomographic images for each of the two or more excitation sources.

48. The system of claim 44, wherein at least a portion of each of the respective scan regions of each of the excitation sources overlap with each other to produce a shared scan region.

49. The system of claim 48, wherein the galvanometer optical scanner is positioned a specific distance, measured along a minimal length optical path from the galvanometer to a location within the shared scan region, to produce a shared scan region of a desired size, based on one or more maximal rotational angles of the one or more galvanometer mirrors.

50. The system of claim 49, wherein the desired size of the shared scan region along a first dimension and/or a second dimension is at least 100 mm.

51-90. -90. (canceled)

91. A method for fast scanning of excitation light over a wide field of view for tomographic imaging of one or more subjects positioned across an object plane, the method comprising:

(a) illuminating the one or more subjects with a beam of excitation light from an excitation source, wherein the excitation source is aligned to direct the beam of excitation light along an optical path from an output of the excitation source to a galvanometer optical scanner comprising one or more rotating galvanometer mirrors, wherein the galvanometer optical scanner is aligned and operable to direct the beam of excitation light to a plurality of locations within a scan region of the object plane via reflection by the one or more rotating galvanometer mirrors, such that as the one or more galvanometer mirrors is/are rotated, the beam of excitation light is scanned across the scan region, thereby providing for illumination of the one or more subjects positioned across the object plane, and

(b) detecting, with one or more detectors, fluorescent light emitted from a fluorescent species within the one or more subjects as a result of excitation by the excitation light;

(c) receiving and/or accessing, by a processor of a computing device, data corresponding to the detected fluorescent light; and

(d) obtaining, by the processor, one or more tomographic images of the one or more subjects using the data corresponding to the detected fluorescent light.

92-133. -133. (canceled)

134. A method for fast scanning of excitation light from a plurality of excitation sources over a wide field of view for tomographic imaging of one or more subjects positioned across an object plane, the method comprising:

(a) illuminating the one or more subjects with at least one beam of excitation light emitted by a respective one of a plurality of excitation sources, wherein;

(i) a first excitation source is aligned to direct its respective beam of excitation light along a first optical path from the first excitation source to a galvanometer optical scanner comprising one or more rotating galvanometer mirrors,

(ii) each excitation source other than the first excitation source is aligned to direct its respective beam of excitation light along an respective optical path towards the galvanometer optical scanner at a corresponding offset angle with respect to the first optical path from the first excitation source to the galvanometer optical scanner,

(iii) the galvanometer optical scanner is aligned and operable to, for each excitation source, direct the respective beam of excitation light emitted by the excitation source to a respective plurality of locations within a respective scan region of the object plane via reflection by the one or more rotating galvanometer mirrors, such that as the one or more galvanometer mirrors are rotated, the respective beam of excitation light emitted by the excitation source is scanned across the respective scan region, thereby providing for illumination of the one or more subjects positioned across the object plane;

(b) detecting, with one or more detectors, fluorescence light emitted from one or more fluorescent species within the one or more subjects as a result of excitation by the excitation light from at least one of the plurality of excitation sources;

(c) receiving and/or accessing, by a processor of a computing device, data corresponding to the detected fluorescent light; and

(d) obtaining, by the processor, one or more tomographic images of the one or more subjects using the data corresponding to the detected fluorescent light.

135-180. -180. (canceled)