Variable-motion optical tomography of small objects

• US 7,197,355 B2
• Filed: 04/19/2002
• Issued: 03/27/2007
• Est. Priority Date: 04/19/2002
• Status: Expired due to Term

• Current Assignee: VisionGate, Inc.
• Original Assignee: VisionGate, Inc.
• Inventors: Nelson, Alan C.
• Primary Examiner(s): MANTIS MERCADER, ELENI M
• Application Number:
  US10/126,026
• Publication Number:
  US 20030199758A1
• Time in Patent Office: 1,803 Days
• Field of Search: 600473-476, 600/425, 600/427, 382/128, 382/133, 382/131, 356/432, 378/4, 378/8, 378/11, 378/21, 378/23, 378/25
• US Class Current: 600/425
• CPC Class Codes: G01N 15/1433 using image recognition
• CPC Class Codes: G01N 15/147 the analysis being performed on a sample stream
• CPC Class Codes: G01N 2015/1006 for cytology
• CPC Class Codes: G01N 2015/1027 Determining speed or velocity of a particle
• CPC Class Codes: G01N 2015/1445 Three-dimensional imaging, imaging in different image planes, e.g. under different angles or at different depths, e.g. by a relative motion of sample and detector, for instance by tomography
• CPC Class Codes: G01N 21/4795 spatially resolved investigating of object in scattering medium in vivo A61B
• CPC Class Codes: G01N 2201/0813 Arrangement of collimator tubes, glass or empty
• CPC Class Codes: G01N 2223/612 biological material
• CPC Class Codes: G06T 11/006 Inverse problem, transformation from projection-space into object-space, e.g. transform methods, back-projection, algebraic methods
• CPC Class Codes: G06T 2211/421 Filtered back projection [FBP]

Abstract

Motion of an object of interest, such as a cell, has a variable velocity that can be varied on a cell-by-cell basis. Cell velocity is controlled in one example by packing cells into a capillary tube, or any other linear substrate that provides optically equivalent 360 degree viewing access, so that the cells are stationary within the capillary tube, but the capillary tube is translated and rotated mechanically through a variable motion optical tomography reconstruction cylinder. The capillary tube motion may advantageously be controlled in a start-and-stop fashion and translated and rotated at any velocity for any motion interval, under the control of a computer program. As such, there are several configurations of the optical tomography system that take advantage of this controlled motion capability. Additionally, the use of polarization filters and phase plates to reduce light scatter and diffraction background noise is described.

Claims

1. A method for variable-motion optical tomography of an object of interest, comprising the steps of:

(a) packing a plurality of objects of interest into a tubular container so that the plurality of objects of interest remain stationary within the tubular container, the tubular container having a central axis;

(b) illuminating the plurality of objects of interest with at least one optical projection beam;

(c) translating the tubular container until at least one object of interest is located within a region of the at least one optical projection beam;

(d) centering the at least one object of interest as necessary;

(e) rotating the tubular container holding the at least one object of interest through a plurality of radial angles that are perpendicular to the central axis;

(f) generating a set of projection images onto at least one detector surface at each radial angle of the plurality of angles, where spaces between the at least one optical projection beam and the at least one object of interest and spaces between the at least one object of interest and the at least one detector surface are filled with a material whose index of refraction is matched with that of the tubular container; and

(g) repeating the steps (b) through (f) until the plurality of objects of interest have been radially scanned.

2. The method of claim 1, wherein the at least one object of interest is a cell or a cell nucleus.

3. The method of claim 1 wherein the optical projection beam is selected from the group consisting of fan beam projections and cone beam projections.

4. A method for three dimensional (3D) reconstruction of an object of interest, the method comprising the steps of:

(a) packing a plurality of objects of interest into a tubular container so that the plurality of objects of interest remain stationary within the tube, where an axis of rotation is aligned with a central axis of the tube;

(b) illuminating the plurality of objects of interest with a plurality of optical projection beams;

(c) translating the linear container until at least one object of interest is located within a region of the plurality of optical projection beams;

(d) centering the at least one object of interest as necessary;

(c) generating a set of projection images onto at least one detector surface at a plurality of radial angles that are perpendicular to the axis of rotation, where spaces between the plurality of optical projection beams and the at least one object of interest and spaces between the object and the at least one detector surface are filled with a material whose index of refraction is matched with that of the tabular container;

(f) repeating the steps (b) through (e) until the objects of interest have been radially scanned; and

(g) reconstructing a 3D image from the set of projection images.

5. A variable-motion optical tomography system comprising:

a tubular container for holding objects of interest having a tube wall and a tube axis, wherein the objects of interest are packed in the tube so as to remain stationary relatively to the tubular container;

a plurality of optical light sources arranged to project light round a circumference at the tube wall;

a plurality of opposing detector surfaces arranged on a wider circumference in the same plane as the light sources, to form a reconstruction zone, so that each light source projects a beam through the tubular container onto a detector area to form projection images, such that one of the projection images does not overlap another on any of the plurality of opposing detector surfaces, and a central axis of each beam intersects the central axes of the other beams within the tube, where spaces between the plurality of optical light sources and the objects of interest and spaces between the objects of interest and the plurality of opposing detector surfaces are filled with a material whose index of refraction is matched with that of the tube; and

means, coupled to the tube, for rotating and translating tubular container in a variable motion.

6. The system of claim 5 wherein the means for moving comprises a computer controlled motion apparatus.

7. The system of claim 5 wherein the means for moving comprises a means for rotating the tubular container such that a set of projections is collected each time the tube is rotated by a rotation displacement value.

8. The system of claim 5 wherein the plurality of optical light sources comprises two or more point sources.

9. The system of claim 5 wherein the plurality of optical light sources include a semicircle of spaced point sources that have opposing detector arrays positioned around an opposite semicircle, tho spaced point sources and the opposing detector arrays being positioned on the same central plane generally perpendicular to the tube axis.

10. The system of claim 5 wherein the plurality of optical light sources and the plurality of opposing detector surfaces lie in the same plane, and the plurality of optical light sources are interspersed between detector arrays.

11. The system of claim 5 wherein additional sets of optical light sources and detectors are positioned above and/or below the reconstruction zone to provide additional projection data.

12. The system of claim 5 wherein at least two polarization filters are positioned between the plurality of light sources and the plurality of opposing detector surfaces.

13. The system of claim 5 wherein at least one phase plate is positioned between the object and the plurality of opposing detector surfaces.