Systems and methods for rapid wide field illumination scanning for in vivo small animal fluorescence tomographic imaging

Patent metadata

Field	Value
Publication number	US-2019021602-A1
Application number	US-201715654442-A
Country	US
Kind code	A1
Filing date	Jul 19, 2017
Priority date	Jul 19, 2017
Publication date	Jan 24, 2019
Grant date	—

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.

First claim

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.

4 . (canceled)

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

tan


(
ϕ
)

<

w

ma



x

-

w
bw

d
2

-

d
1

,

wherein:
w max is an upper bound for a desired spot size of the beam of excitation light within the scan region,
w bw is a spot size of the beam of excitation light at its beam waist location,
d 1 is a minimal distance measured along a minimal length optical path from the galvanometer optical scanner to a location within the scan region, and
d 2 is a maximal distance along a maximal length optical path from the galvanometer optical scanner to a location within the scan region.

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.

10 - 13 . (canceled)

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

tan


(
ϕ
)

<

w

ma



x

-

w
bw

d
2

-

d
1

,

wherein:
w max is an upper bound for a desired spot size of the beam of excitation light,
w bm is a spot size of the beam of excitation light at a beam waist,
d 1 is a minimal distance along a minimal length optical path from the galvanometer optical scanner to a location within the scan region, and
d 2 is a maximal distance along a maximal length optical path from the galvanometer optical scanner to a location within the scan region.

18 . The system of claim 15 , wherein a half-angle divergence of the

Assignees

• Perkinelmer Health Sci Inc

Inventors

• Hurley William
• Behrooz Ali
• Meltzer Michael
• Wilson Andrew

Classifications

• G06T12/00

  Tomographic reconstruction from projections · CPC title

• G02B19/0014

  at least one surface having optical power · CPC title

• G06T7/0012

  Biomedical image inspection · CPC title

• A61B5/0062

  Arrangements for scanning · CPC title

• G02B19/0052

  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 title