Device for the optical inspection of a fluid, especially for hematological analyses

• US 5,730,941 A
• Filed: 05/24/1996
• Issued: 03/24/1998
• Est. Priority Date: 05/24/1995
• Status: Expired due to Term

• Current Assignee: A B X
• Original Assignee: A B X
• Inventors: Lefevre, Didier, Kress, Bernard
• Primary Examiner(s): SNAY, JEFFREY R
• Application Number:
  US08/653,325
• Time in Patent Office: 669 Days
• Field of Search: 422/82.05, 422/82.08, 422/82.09, 422/73, 436/164, 436/172, 436/63, 356/72, 356/73, 356/336, 356/338
• US Class Current: 422/73
• CPC Class Codes: G01N 15/14 Optical investigation techniques, e.g. flow cytometry

Abstract

It includes a measuring space (8) comprising a constrained passage (15) for the fluid, a monochromatic light source (31) delivering a beam (F1) to optical elements (6, 32, 34) including a first diffractive optical element (32) having a diffractive network (38) predetermined as a function, on the one hand, of the characteristics of the source and, on the other hand, of chosen geometrical and spectral characteristics for the illumination of the constrained passage, and suitable for inducing fluorescence of at least part of the fluid, and first (19-20), second (34-36) and third (40) optoelectronic elements intended to collect, respectively, a transmitted beam, fluorescence and a diffracted beam, and suitable for delivering to an analysis unit (24) signals relating to the contents of the beams. At least one of the beams emanates from a second diffractive optical element (42) having a second diffractive optical network which is predetermined as a function of a frequential and geometrical transfer function of at least one of the optoelectronic elements.

Claims

1. Device for the optical inspection of a fluid, of the type which includes:

a measuring space (8) comprising a constrained passage (15) for the fluid,

a light source (31),

an analysis unit,

upstream optical means (6, 32,

     34) suitable for collecting the light (F1) emanating from the source (31) and for delivering said collected light (F1) at the level of the constrained passage (15) in the form of an upstream delivered light (FC) having chosen geometrical and spectral characteristics,

first sensor means (20) suitable for delivering to said analysis unit (24) first signals which are representative of first data conveyed by a collected light (FT),

first downstream optical means (18, 19,

     42) for collecting at least part of the light (FT) obtained after passage through the constrained passage (15) and delivering said collected light (FT) from the constrained passage to the first sensor means (20) in the form of a downstream delivered light (FTT, FTD) having chosen geometrical and spectral characteristics,

wherein at least one of the upstream optical means (32) and of the first downstream optical means (42) includes at least one first diffractive optical element (32;

     42) of which at least one of the surfaces (33;

     43), which interact with the light that they collect, has a first predetermined three-dimensional motif which is suitable for carrying out a predetermined interaction between the light that it collects (F1;

FT) and the light that it delivers (FC;

FTT, FTD).

2. Device according to claim 1, wherein the first diffractive optical element (32) is of the Fresnel type.

3. Device according to claim 1, wherein the first diffractive optical element (32) is of the Fourier type.

4. Device according to claim 1, wherein the geometrical and spectral characteristics chosen, which are required for the illumination of the constrained passage (15), include uniform illumination, at the wavelength chosen, of a substantially plane, closed surface having a given geometry.

5. Device according to claim 4, wherein the illuminated surface is a rectangle.

6. Device according to claim 1, wherein the light source (31) is a source having substantially monochromatic radiation, the emission wavelength of which is chosen in such a way that it induces fluorescence of at least part of the fluid passing through the constrained passage (15).

7. Device according to claim 6, wherein it includes second sensor means (36) which are intended to deliver to the analysis unit (24) second signals which are representative of second data conveyed by fluorescence emitted by the fluid at the time of its interaction with the light (FC) at the level of the constrained passage (15).

8. Device according to claim 7, wherein at least one of the diffractive optical elements has a predetermined three-dimensional motif suitable for ensuring filtering of the wavelength and of the geometrical distribution of fluorescence, and for delivering to the second sensor means (36) a fluorescence light having chosen geometrical and spectral characteristics.

9. Device according to claim 1, wherein it includes third sensor means (40) intended to deliver to the analysis unit (24) third signals which are representative of third data conveyed by the light (FTD) diffracted by the fluid at the time of its interaction with the light (FC) at the level of the constrained passage.

10. Device according to claim 9, wherein the first downstream optical means include at least one second diffractive optical element (42), of which at least one of the surfaces (43), which interact with the light (FT) obtained after passage through the constrained passage (15), has a second three-dimensional motif which is predetermined as a function of a frequential and geometrical transfer function of at least one of the first (20) and third (40) sensor means.

11. Device according to claim 10, wherein the second diffractive optical element (42) is of the Fourier type.

12. Device according to claim 10, wherein the second diffractive optical element (42) is of the Fresnel type.

13. Device according to claim 10, wherein the second diffractive optical element includes a single surface (43) comprising a diffracting motif of the Fourier type with sixteen levels.

14. Device according to claim 10, wherein at least one of the diffractive optical elements has a predetermined three-dimensional motif suitable for ensuring spatial separation of predetermined wavelengths.

15. Device according to claim 9, wherein the downstream optical means include the first diffractive optical element (42), of which at least one of the surfaces (43), which interact with the light (F1) delivered by the source (31), has the first three-dimensional motif which is predetermined as a function of a frequential and geometrical transfer function between at least one of the first (20) and third (40) sensor means.

16. Device according to claim 15, wherein the first three-dimensional motif is a first (48) diffractive network engraved in a transparent substrate (49) at the wavelengths of emission of the source and of fluorescence.

17. Device according to claim 1, wherein the upstream optical means include the first diffractive optical element (32), of which at least one of the surfaces (33), which interact with the light (F1) delivered by the source (31), has the first three-dimensional motif which is predetermined as a function of the characteristics of the source (31) and of the chosen characteristics required for the illumination (FC) of the constrained passage (15).

18. Device according to claim 17, wherein the first diffractive optical element (32) includes a single surface (33) comprising a diffracting motif of the Fresnel type with sixteen levels.

19. Device according to claim 17, wherein the first and second three-dimensional motifs are, respectively, first (38) and second (48) diffractive networks engraved in transparent substrates (39;

49) at the emission wavelength of the source and/or the fluorescence wavelength.

20. Device according to claim 19, wherein the first and second diffractive networks (38, 48) are of the digital type with relief modulation, the said modulation representing a predetermined function capable of coherent diffracting action on the phase and/or amplitude, respectively, of the light (F1) emitted by the source (31) and of the light (FT) obtained after passage through the constrained passage (15).

21. Device according to claim 20, wherein the first and second diffractive networks each possess relief modulation of at least two levels.