Imaging and analyzing parameters of small moving objects such as cells in broad flat flow

• US 6,671,044 B2
• Filed: 11/16/2001
• Issued: 12/30/2003
• Est. Priority Date: 01/25/1999
• Status: Expired due to Term

• Current Assignee: Cytek Biosciences Inc
• Original Assignee: Amnis Corporation (DiaSorin S.p.A.)
• Inventors: Basiji, David A., Ortyn, William E.
• Primary Examiner(s): EVANS, FANNIE L
• Application Number:
  US09/989,031
• Publication Number:
  US 20020030812A1
• Time in Patent Office: 774 Days
• Field of Search: 356/73, 356/326, 356/328, 356/419, 356/417, 356/318, 250/458.1, 250/459.1, 250/461.1, 250/461.2
• US Class Current: 356/326
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G01J 3/2823 Imaging spectrometer
• CPC Class Codes: G01N 15/147 the analysis being performed on a sample stream
• CPC Class Codes: G01N 2015/0294 Particle shape
• CPC Class Codes: G01N 2015/1006 for cytology
• CPC Class Codes: G01N 2015/1472 with colour
• CPC Class Codes: G01N 2015/1477 Multiparameters
• CPC Class Codes: G01N 2015/1486 Counting the particles
• CPC Class Codes: G01N 2015/1497 Particle shape
• CPC Class Codes: G01N 2021/052 Tubular type; cavity type; multireflective
• CPC Class Codes: G01N 2021/058 Flat flow cell
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/6456 Spatial resolved fluorescence measurements; Imaging
• CPC Class Codes: G01N 21/85 Investigating moving fluids or granular solids
• CPC Class Codes: G02B 27/1013 for colour or multispectral image sensors, e.g. splitting an image into monochromatic image components on respective sensors spectral imaging systems G01J
• CPC Class Codes: G02B 27/126 The splitting element being a prism or prismatic array, including systems based on total internal reflection
• CPC Class Codes: G02B 27/144 using partially transparent surfaces without spectral selectivity G02B27/147 takes precedence
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: G02B 27/148 including stacked surfaces having at least one double-pass partially reflecting surface
• CPC Class Codes: G02B 7/28 Systems for automatic generation of focusing signals

Abstract

Light from an object such as a cell moving through an imaging system is collected and dispersed so that it can be imaged onto a time delay and integration (TDI) detector. The light can be emitted from a luminous object or can be light from a light source that has been scattered or not absorbed by the object or can include a light emission by one or more probes within or on the object. Multiple objects passing through the imaging system can be imaged, producing both scatter images and dispersed images at different locations on one or more TDI detectors.

Claims

1. An imaging system adapted to determine one or more characteristics of an object in a broad, flat flow, from an image of the object while there is relative movement between the object and the imaging system comprising:

(a) a collection lens having a field angle in an object space that is sufficiently large to collect light traveling from the object that is in the broad, flat flow so that the light passes through the collection lens and travels along a collection path;

(b) a dispersing component disposed in the collection path so as to receive the light from the object that has passed through the collection lens, dispersing the light into a plurality of separate light beams, each light beam being directed away from the dispersing component in a different predetermined direction;

(c) an imaging lens disposed to receive the light beams from the dispersing component, producing a plurality of images corresponding to each of the light beams, each image being projected by the imaging lens toward a different predetermined location; and

(d) a time delay integration (TDI) detector disposed to receive the plurality of images produced by the imaging lens, producing an output signal that is indicative of at least one characteristic of the object in the broad, flat flow, said TDI detector producing the output signal by integrating light from at least a portion of the object over time, while the relative movement between the object and the imaging system occurs.

2. The imaging system of claim 1, wherein the dispersing component comprises a spectral dispersing component including a plurality of beam splitters arranged to reflect light of predetermined spectral characteristics at different predefined angles, all light from each beam splitter corresponding to a separate light beam, each light beam leaving the spectral dispersing component at a different nominal angle.

3. The imaging system of claim 2, wherein the beam splitters are disposed in the collection path adjacent to one another so as to receive the light from the object in the broad, flat flow after said light has passed through the collection lens, and arranged so that light reflected by all but a first beam splitter in the spectral dispersing component passes through at least one preceding beam splitters a second time.

4. The imaging system of claim 3, wherein wedge-shaped substrates define an angular difference between each beam splitter, and wherein the beam splitters are sandwiched between the wedge-shaped substrates, forming a monolithic structure.

5. The imaging system of claim 2, wherein the beam splitters are disposed in the collection path so as to receive the light from the object in the broad, flat flow that has passed through the collection lens and separated from each other by a sufficient distance such that light reflected by any of the beam splitters does not pass through any other beam splitter within the spectral dispersing component a second time.

6. The imaging system of claim 2, further including a bandpass filter assembly disposed between the TDI detector and the imaging lens, said bandpass filter assembly comprising a plurality of adjacent filter segments, each filter segment being positioned to receive a different light beam from an associated beam splitter in the spectral dispersing component and having a spectral transmission characteristic such that light having a wavelength within a predefined waveband passes through the filter segment, while light having a wavelength outside of the waveband is attenuated by the filter segment.

7. The imaging system of claim 1, wherein the light from the object in the broad, flat flow that has passed through the collection lens is dispersed in a plane that is orthogonal to a direction of the relative movement between the object and the imaging system.

8. The imaging system of claim 1, wherein the image of the object produced by the imaging lens moves across the TDI detector in correspondence with the relative movement between the object and the imaging system.

9. The imaging system of claim 1, wherein the light from the object in the broad, flat flow comprises an unstimulated emission from the object.

10. The imaging system of claim 1, further comprising a light source that is disposed to provide an incident light that illuminates the object in the broad, flat flow.

11. The imaging system of claim 10, wherein the object in the broad, flat flow scatters the incident light producing scattered light, the scattered light at least in part passing through the collection lens.

12. The imaging system of claim 10, wherein the incident light illuminating the object in the broad, flat flow stimulates the object to emit light that at least in part passes through the collection lens.

13. The imaging system of claim 10, wherein the incident light is at least partially absorbed by the object in the broad, flat flow, so that the light passing through the collection lens does not include a portion of the light absorbed by the object.

14. The imaging system of claim 10, wherein the incident light is reflected from the object in the broad, flat flow toward the collection lens.

15. The imaging system of claim 10, wherein the light source comprises at least one of:

(a) a coherent light source;

(b) a non-coherent light source;

(c) a pulsed light source; and

(d) a continuous light source.

16. The imaging system of claim 1, wherein the object is entrained within a broad flat flow of a fluid stream that moves the object past the collection lens.

17. The imaging system of claim 1, wherein the TDI detector responds to the image of the object in the broad, flat flow by producing a signal that propagates through the TDI detector.

18. The imaging system of claim 17, wherein a propagation rate of the signal through the TDI detector is synchronized with a motion of the image of the object in the broad, flat flow on the TDI detector as a result of the relative movement between the object and the imaging system.

19. The imaging system of claim 17, wherein a propagation rate of the signal through the TDI detector is not synchronized with a motion of the image of the object in the broad, flat flow on the TDI detector as a result of the relative movement between the object and the imaging system.

20. The imaging system of claim 1, further comprising an objective lens disposed between the object in the broad flat flow and the collection lens, said objective lens having a focal point at which the object is imaged;

and an optical slit aligned with a direction of the relative movement between the object and the imaging system and disposed between the objective lens and the collection lens at the focal point of the objective lens, said slit substantially preventing extraneous light from reaching the collection lens by transmitting to the collection lens the light from the object that is focused on the slit by the objective lens.

21. The imaging system of claim 1, wherein the light from the object in the broad, flat flow is provided in a plurality of different modes, including light that is scattered by the object, light that is reflected by the object, light remaining after the object has absorbed a portion of light that is incident on the object, light produced as a stimulated emission from the object, and light produced as an unstimulated emission from the object, said imaging lens directing light so as to simultaneously produce images on the TDI detector derived from light provided by at least any two of said plurality of modes.

22. An imaging system adapted to determine one or more characteristics of an object in a broad, flat flow, from an image of the object while there is relative movement between the object and the imaging system, comprising:

(a) a collection lens having a field angle in an object space that is sufficiently large to collect light traveling from the object that is in the broad, flat flow so that the light passes through the collection lens and travels along a collection path;

(b) a light dispersing element disposed in the collection path so as to disperse the light that has passed through the collection lens, producing dispersed light;

(c) an imaging lens disposed to receive the dispersed light, producing an image from the dispersed light; and

(d) a time delay integration (TDI) detector disposed to receive the image produced by the imaging lens, producing an output signal that is indicative of at least one characteristic of the object in the broad, flat flow, said TDI detector producing the output signal by integrating light from at least a portion of the object over time, while the relative movement between the object and the imaging system occurs.

23. The imaging system of claim 22, wherein the light dispersing element spectrally disperses the light that has passed through the collection lens, and wherein the dispersed light is spectrally dispersed across the TDI detector.

24. The imaging system of claim 22, wherein the light that has passed through the collection lens is dispersed in a plane that is orthogonal to a direction of the relative movement between the object in the broad, flat flow and the imaging system.

25. The imaging system of claim 22, wherein the image of the object produced by the imaging lens moves across the TDI detector as the relative movement between the object and the imaging system occurs.

26. The imaging system of claim 22, wherein the light from the object in the broad, flat flow comprises an unstimulated emission from the object.

27. The imaging system of claim 22, further comprising a light source that is disposed to provide an incident light that illuminates the object.

28. The imaging system of claim 27, wherein the object in the broad, flat flow scatters the incident light, said light that is scattered from the object at least in part passing through the collection lens.

29. The imaging system of claim 27, wherein the incident light illuminating the object stimulates the object in the broad, flat flow to emit the light that passes through the collection lens.

30. The imaging system of claim 27, wherein the incident light is at least partially absorbed by the object in the broad, flat flow, so that the light passing through the collection lens does not include a portion of the light absorbed by the object.

31. The imaging system of claim 27, wherein the object is entrained within a broad flat flow of a fluid stream that moves the object past the collection lens.

32. The imaging system of claim 27, wherein the light source comprises at least one of:

(a) a coherent light source;

(b) a non-coherent light source;

(c) a pulsed light source; and

(d) a continuous light source.

33. The imaging system of claim 22, wherein the object is carried on a support past the collection lens.

34. The imaging system of claim 22, wherein the TDI detector responds to the image of the object by producing a signal that propagates through the TDI detector.

35. The imaging system of claim 34, wherein a propagation rate of the signal through the TDI detector is synchronized with a motion of the image of the object in the broad, flat flow on the TDI detector as a result of the relative movement between the object and the imaging system.

36. The imaging system of claim 34, wherein a propagation rate of the signal through the TDI detector is not synchronized with a motion of the image of the object in the broad, flat flow on the TDI detector as a result of the relative movement between the object and the imaging system.

37. The imaging system of claim 22, wherein the dispersing element comprises a prism.

38. The imaging system of claim 22, further comprising an objective lens disposed between the object and the collection lens, having a focal point at which the object in the broad, flat flow is imaged;

and an optical slit aligned with a direction of the relative movement between the object and the imaging system and disposed between the objective lens and the collection lens at the focal point of the objective lens, said slit substantially preventing extraneous light reaching the collection lens by transmitting to the collection lens the light from the object that is focused on the slit by the objective lens.

39. The imaging system of claim 22, wherein the light from the object in the broad, flat flow is provided in a plurality of different modes, including light that is scattered by the object, light that is reflected by the object, light remaining after the object has absorbed a portion of light that is incident on the object, light produced as a stimulated emission from the object, and light produced as an unstimulated emission from the object, said imaging lens directing the dispersed light so as to simultaneously produce images on the TDI detector derived from light provided by at least any two of said plurality of modes.