Patent US3975084A successfully refreshed from Google Patents.
US3975084A
Expired / Lapsed
US
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Particle detecting system
Assignee: Bio Rad Laboratories Inc
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Filing: 1974-08-19
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Granted: 1976-08-17
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Expires: 1994-08-19
Abstract
Abstract Submicron-sized particles are detected by a system which observes emission, as by scattering or by fluorescence from particles undergoing Brownian motion in a region of a fluid medium excited by an evanescent wave created adjacent an interface between the fluid medium and a multiple internal totally reflecting cell or light guide. The excited region can range in depth between several wavelengths and a fraction of the wavelength of the exciting beam, hence serves as an "aperture" having a dimension of about the same order of magnitude as the particles being detected. The particles can be classified according to size by examining the amplitude modulation arising out of the motion of the particles through the aperture.
Inventors
- 👤 Myron J. Block
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:19
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/02; G01N15/0205; G01N21/00; G01N21/17; G01N21/55; G01N21/552
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
76 words
Apparatus for detecting submicron dimensional particles in a fluid medium, said apparatus comprising, in combination: a totally internally reflecting cell bounded at least in part by an interface with said medium; and imaging optical means including means for focussing said optical means so that the first conjugate plane thereof is substantially coincident with the region of said medium traversed by an evanescent wave formed upon internal reflection of an exciting beam of radiation within said cell.
Claim 2
Dependent Claim
76 words
Apparatus for detecting submicron dimensional particles in a fluid medium, said apparatus comprising, in combination: a totally internally reflecting cell bounded at least in part by an interface with said medium; and imaging optical means including means for focussing said optical means so that the first conjugate plane thereof is substantially coincident with the region of said medium traversed by an evanescent wave formed upon internal reflection of an exciting beam of radiation within said cell.
Claim 3
Dependent Claim
16 words
Apparatus as defined in claim 1 wherein said first conjugate plane is coincident with said region.
Claim 4
Dependent Claim
32 words
Apparatus as defined in claim 1 including means for detecting, with respect to particles in Brownian motion in said region, intensity modulation of radiation emitted by said particles responsively to said wave.
Claim 5
Dependent Claim
13 words
Apparatus as defined in claim 3 including means for frequency analyzing said modulation.
Claim 6
Dependent Claim
106 words
Apparatus for detecting submicron-dimensioned particles in a fluid medium, and comprising in combination; a totally internally reflecting cell bounded at least in part by a surface for forming an interface with said medium, said cell being formed of a material having a higher refractive index than said medium; means for detecting radiant emission from particles in Brownian motion in the region of said medium adjacent said interface and traversed by evanescent waves formed upon passage of totally reflected illumination through said cell; and means for frequency analyzing the modulation of said radiant emission created by said motion of said particles across the boundary of said region.
Claim 7
Dependent Claim
106 words
Apparatus for detecting submicron-dimensioned particles in a fluid medium, and comprising in combination; a totally internally reflecting cell bounded at least in part by a surface for forming an interface with said medium, said cell being formed of a material having a higher refractive index than said medium; means for detecting radiant emission from particles in Brownian motion in the region of said medium adjacent said interface and traversed by evanescent waves formed upon passage of totally reflected illumination through said cell; and means for frequency analyzing the modulation of said radiant emission created by said motion of said particles across the boundary of said region.
Claim 8
Dependent Claim
14 words
Apparatus as defined in claim 5 wherein said means for detecting comprises a microscope.
Claim 9
Dependent Claim
27 words
Apparatus as defined in claim 5 including means for directing a beam of said illumination into said cell at an adjustable angle with respect to said interface.
Claim 10
Dependent Claim
19 words
Apparatus as defined in claim 5 wherein said cell is disposed between said means for detecting and said region.
Claim 11
Dependent Claim
19 words
Apparatus as defined in claim 5 wherein said region is disposed between said cell and said means for detecting.
Claim 12
Dependent Claim
21 words
Apparatus as defined in claim 5 including means for wavelength filtering radiant emission from said particles prior to detecting said emission.
Claim 13
Dependent Claim
12 words
Apparatus as defined in claim 5 including a source of said illumination.
Claim 14
Dependent Claim
13 words
Apparatus as defined in claim 11 wherein said source provides substantially monochromatic illumination.
Claim 15
Dependent Claim
99 words
Apparatus for providing modulated radiation emission from particles moving in a fluid medium, said apparatus comprising in combination, a totally internally reflecting cell bounded at least in part by a surface for forming an interface with said medium, and means for providing a pair of coplanar beams, each being temporally coherent and forming an angle with respect to one another in their common plane, said means being positioned with respect to said cell so that said beams can traverse said cell by total internal reflection, at least in part, from said surface at substantially the same angle of incidence.
Claim 16
Dependent Claim
99 words
Apparatus for providing modulated radiation emission from particles moving in a fluid medium, said apparatus comprising in combination, a totally internally reflecting cell bounded at least in part by a surface for forming an interface with said medium, and means for providing a pair of coplanar beams, each being temporally coherent and forming an angle with respect to one another in their common plane, said means being positioned with respect to said cell so that said beams can traverse said cell by total internal reflection, at least in part, from said surface at substantially the same angle of incidence.
Claim 17
Dependent Claim
26 words
Apparatus as defined in claim 13 including means for detecting radiant emission from particles in Brownian motion in the region of said medium adjacent said interface.
Claim 18
Dependent Claim
16 words
Apparatus as defined in claim 13 including means for variably adjusting the magnitude of said angle.
Claim 19
Dependent Claim
18 words
Apparatus as defined in claim 13 wherein said beams are both substantially monochromatic at substantially the same wavelengths.
Claim 20
Dependent Claim
34 words
Apparatus as defined in claim 13 wherein said means for providing said beams comprises a source of substantially monochromatic radiation and beam splitter means for splitting said monochromatic radiation into said pair of beams.
Claim 21
Dependent Claim
100 words
Method of detecting submicron-dimensional particles in a fluid medium, and comprising the steps of; illuminating said medium with evanescent waves arising in a region of said fluid medium adjacent an interface between said fluid medium and a surface bounding another medium of higher refractive index through which a beam of exciting radiation is propagating by total reflection from, at least in part, said interface, detecting radiation emitted responsively to said evanescent waves by particles in Brownian motion in said region, and frequency analyzing modulation of the radiant emission created by motion of said particles across the boundary of said region.
Claim 22
Dependent Claim
100 words
Method of detecting submicron-dimensional particles in a fluid medium, and comprising the steps of; illuminating said medium with evanescent waves arising in a region of said fluid medium adjacent an interface between said fluid medium and a surface bounding another medium of higher refractive index through which a beam of exciting radiation is propagating by total reflection from, at least in part, said interface, detecting radiation emitted responsively to said evanescent waves by particles in Brownian motion in said region, and frequency analyzing modulation of the radiant emission created by motion of said particles across the boundary of said region.
Claim 23
Dependent Claim
21 words
Method as defined in claim 18 wherein the step of detecting comprises detecting scattering of said evanescent waves from said particles.
Claim 24
Dependent Claim
26 words
Method as defined in claim 18 wherein said beam of exciting radiation is selected to include wavelengths which are capable of exciting fluorescence in said particles.
Claim 25
Dependent Claim
35 words
Method as defined in claim 18 including the steps of staining said particles with a fluorescent stain, said illuminating being with evanescent waves arising from propagation of exciting radiation having excitation wavelengths of said stain.
Claim 26
Dependent Claim
69 words
Method as defined in claim 18 including the steps of staining said particles with a plurality of fluorescent stains each of which has a different characteristic fluorescent emission band, said illuminating being with evanescent waves arising from propagation of exciting radiation having excitation wavelengths of said stains, and wavelength filtering the radiation emitted by said particles so as to distinguish between fluorescence arising from different ones of said stains.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-17 | 1980-02-16 | 1980-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-17 | 1984-02-16 | 1984-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-17 | 1988-02-16 | 1988-08-17 | $7700.00 | Window Closed / Lapsed |