Distinguishing objects

• US 20080186488A1
• Filed: 02/05/2007
• Published: 08/07/2008
• Est. Priority Date: 02/05/2007
• Status: Active Grant

• Current Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Kiesel, Peter, Bassler, Michael, Schmidt, Oliver
• Granted Patent: US 7,817,276 B2
• Time in Patent Office: Days
• US Class Current: 356/335
• CPC Class Codes: G01N 2021/0346 Capillary cells; Microcells
• CPC Class Codes: G01N 2021/391 Intracavity sample
• CPC Class Codes: G01N 21/0303 Optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment G01N21/031 - G01N21/15 take precedence
• CPC Class Codes: G01N 21/39 using tunable lasers

Abstract

While objects travel through an optical cavity, the cavity provides output light that is affected by the objects, causing the output light to have a varying intensity function. The output light is photosensed to obtain sensing results that depend on the varying intensity function. The sensing results are used to distinguish at least one object, such as from its environment or from objects of other types. The objects can, for example, be particles or biological cells, and their optical characteristics, such as refractive index or absorption, can affect the output light, so that information about them is included in the output light. The output light can, for example, have a laterally varying intensity function with peaks whose features change due to the objects. The sensing results can also be used to track objects, together with other information, such as about the speed of a fluid that carries the objects through the cavity.

Claims

1. A method of using optical cavities;

the method comprising;

while objects travel through an optical cavity, illuminating the cavity to provide output light, the objects affecting the output light, the output light having a laterally varying intensity function that includes information about the objects while the objects travel through the cavity;

photosensing the output light to obtain sensing results that depend on the laterally varying intensity function; and

using the sensing results to distinguish at least one of the objects.

2. The method of claim 1, further comprising:

controlling the manner in which the objects travel through the optical cavity.

3. The method of claim 1 in which the act of photosensing the output light comprises:

receiving the output light on a photosensitive surface, the laterally varying intensity function affecting the output light'"'"'s position on the photosensitive surface;

the sensing results depending on the output light'"'"'s position.

4. The method of claim 1 in which the act of using the sensing results comprises at least one of locating, counting, sorting, selecting, directing, separating, and determining paths of objects.

5. The method of claim 1 in which the objects include two or more types and objects of each type affect the output light differently than objects of other types affect it;

the act of using the sensing results comprising;

distinguishing at least one of the objects from one or more objects of other types.

6. The method of claim 5 in which the objects include biological cells.

7. The method of claim 6 in which the two or more types include a type of cancer cells and a type of non-cancer cells;

the method further comprising distinguishing cancer cells from non-cancer cells.

8. The method of claim 6 in which the two or more types include a type of rare cells;

the method further comprising distinguishing rare cells.

9. The method of claim 5, further comprising:

measuring sizes of objects that travel through the optical cavity;

the act of using the sensing results comprising;

using the sensing results and the measured sizes to distinguish at least one of the objects from one or more objects of other types.

10. The method of claim 1 in which the act of using the sensing results comprises:

using the sensing results to obtain information about at least one of refractive index and absorption of an object.

11. The method of claim 1 in which the laterally varying intensity function includes one or more peaks, the act of using the sensing results comprises:

using the sensing results to detect a change in a feature of the laterally varying intensity function.

12. The method of claim 11 in which the feature is one of a central value, a maximum intensity, a contrast, and an intermediate intensity width of at least one of the peaks.

13. The method of claim 1 in which the act of using the sensing results comprises:

tracking one or more of the objects by using the sensing results to obtain position data indicating the tracked object'"'"'s position.

14. The method of claim 13 in which the act of tracking one or more of the objects comprises:

measuring a flow velocity of a medium through the cavity;

using the sensing results and the measured flow velocity to track one or more of the objects.

15. A system comprising:

an optical cavity component that includes an optical cavity through which objects travel, the optical cavity being operable to provide output light in response to illumination, the objects affecting the output light, the output light having a laterally varying intensity function that includes information about the objects while the objects travel through the cavity;

a light source component that illuminates the optical cavity;

a photosensing component that photosenses the output light to obtain sensing results that depend on the laterally varying intensity function; and

an object distinguishing component that uses the sensing results to distinguish at least one of the objects.

16. The system of claim 15 in which the optical cavity is one of a homogeneous or inhomogeneous transmissive cavity.

17. The system of claim 15 in which the optical cavity provides output light in a mode with the mode'"'"'s respective intensity function having a respective intensity peak.

18. The system of claim 17 in which the cavity is a transmissive cavity;

the modes being transmission modes or reflection modes.

19. The system of claim 18 in which the intensity function of each of the at least one of the modes includes information about an optical characteristic of one or more objects traveling through the optical cavity.

20. The system of claim 15 in which the photosensing component is one of a photosensing array or a position-sensitive detector.

21. The system of claim 20 in which the photosensing component includes one or more arrays that include photosensing cells, the photosensing cells of at least one of the arrays being sized so that output light that includes information about one of the objects is concurrently photosensed by a set of two or more of the photosensing cells of one of the arrays.

22. The system of claim 15 in which the object distinguishing component includes processing circuitry connected to receive the sensing results from the photosensing component.

23. A method of using optical cavities;

the method comprising;

while objects travel through an optical cavity in a medium, operating the cavity to provide-output light;

objects of one or more trackable types affecting output light provided by the cavity so that it is different than the cavity would provide if no objects were in the medium;

the output light having a varying intensity function while the objects travel through the cavity;

photosensing the output light to obtain sensing results that depend on the varying intensity function; and

using the sensing results to track a set of the objects of the trackable types and to distinguish at least one of the tracked objects.

24. The method of claim 23 in which the objects include biological cells.

25. The method of claim 24 in which the one or more types include a type of cancer cells and a type of non-cancer cells.

26. The method of claim 23, further comprising:

measuring sizes of objects in the set;

the act of using the sensing results comprising;

using the sensing results and the measured sizes to distinguish at least one of the tracked objects.

27. The method of claim 23 in which the act of using the sensing results comprises:

using the sensing results to obtain information about at least one of refractive index and absorption of a tracked object.

28. The method of claim 23 in which the act of using the sensing results comprises:

using the sensing results to detect a photon energy shift.

29. The method of claim 23 in which the act of using the sensing results comprises:

tracking each tracked object by using the sensing results to obtain position data indicating the tracked object'"'"'s position.

30. The method of claim 23, further comprising:

measuring a flow velocity of the medium through the cavity;

the act of using the sensing results comprising;

using the sensing results and the measured flow velocity to track each tracked object.

31. The method of claim 23 in which the medium with the objects follows a path through the cavity, the act of photosensing the output light comprising:

photosensing at a series of positions along the path, with photosensing being performed at each position for a respective subrange of photon energies;

the act of using the sensing results comprising;

using the sensing results from each position to obtain information about an optical characteristic in the respective subrange of photon energies.

32. The method of claim 23 in which the medium with the objects concurrently follows two or more paths through the cavity, the act of photosensing the output light comprising:

concurrently photosensing along each path;

the act of using the sensing results comprising;

using the sensing results from more than one of the paths to distinguish at least one of the tracked objects.