US5073029A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multisource device for photometric analysis and associated chromogens
Assignee: EQM Res Inc
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Filing: 1990-02-16
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Granted: 1991-12-17
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Expires: 2010-02-16
Abstract
Abstract An optoelectronic device is provided which permits rapid sequential measurement of the optical density of multiple samples. The device employs a plurality of light-emitting diodes (LEDs) as light sources and a plurality of photodiodes as light detectors. In a preferred embodiment, arrays of LEDs paired with photodiodes are adapted to measure the optical density of samples contained in multiwell plastic plates (microplates) conventionally used for immunoassays.
Inventors
- 👤 James P. Eberly
- 👤 Ralph A. Magnotti, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:46
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/251; G01N21/253; G01N21/255; G01N2201/00; G01N2201/04; G01N2201/0407; G01N2201/0446; G01N2201/06; G01N2201/062; G01N2201/0621
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
223 words
An optoelectronic instrument for measuring the absorbance of a plurality of samples, comprising: a plurality of LED-photodetector pairs, each of the said pairs being internally aligned so that light emitted by the said LED member is directed toward the photoreceptive surface of the corresponding said photodetector member of said pair, the said plurality of LED-photodetector pairs being arranged to form a spatial array of adjacent pairs, means for removably positioning said plurality of samples so that each said sample is positioned between the said LED member and the said corresponding photodetector member of a said pair, so that the light from the LED member of such pair passes through the said sample before striking the said photodetector member of said pair, electronic means for sequentially pulsing the LED members of said array, said sequential pulsing occurring in a sequence such that when absorbance of any particular said sample is being measured, the particular said LED member which corresponds to the said particular sample emits light, while said LED members which correspond to samples adjacent to said particular sample do not emit light simultaneously with said particular LED member, and electronic means for sequentially measuring the signal from each said photodetector during the interval in which its corresponding said LED member is emitting light, and calculating the absorbance or transmittance of corresponding said sample.
Claim 2
Dependent Claim
223 words
An optoelectronic instrument for measuring the absorbance of a plurality of samples, comprising: a plurality of LED-photodetector pairs, each of the said pairs being internally aligned so that light emitted by the said LED member is directed toward the photoreceptive surface of the corresponding said photodetector member of said pair, the said plurality of LED-photodetector pairs being arranged to form a spatial array of adjacent pairs, means for removably positioning said plurality of samples so that each said sample is positioned between the said LED member and the said corresponding photodetector member of a said pair, so that the light from the LED member of such pair passes through the said sample before striking the said photodetector member of said pair, electronic means for sequentially pulsing the LED members of said array, said sequential pulsing occurring in a sequence such that when absorbance of any particular said sample is being measured, the particular said LED member which corresponds to the said particular sample emits light, while said LED members which correspond to samples adjacent to said particular sample do not emit light simultaneously with said particular LED member, and electronic means for sequentially measuring the signal from each said photodetector during the interval in which its corresponding said LED member is emitting light, and calculating the absorbance or transmittance of corresponding said sample.
Claim 3
Dependent Claim
29 words
The optoelectronic instrument of claim 1, wherein the said spatial array of adjacent LED-photodiode pairs is adapted to measure the said plurality of samples contained in a multiwell microplate.
Claim 4
Dependent Claim
34 words
The optoelectronic instrument of claim 2, wherein the light emitted from each LED member is collimated through a cylindrical aperture, each said aperture having a height-to-diameter ratio of between approximately 4 and approximately 7.5.
Claim 5
Dependent Claim
20 words
The optoelectronic instrument of claim 3, wherein each said aperture has a diameter of between approximately 0.05 and 0.07 inches.
Claim 6
Dependent Claim
31 words
The optoelectronic instrument of claim 2, comprising in addition a long-wavelength cutoff filter means adapted to minimizing polychromatic error, said filter means being interposed between the LED members and photodetector means.
Claim 7
Dependent Claim
55 words
The optoelectronic instrument of claim 5, wherein the plurality of LED embers are green LEDs exhibiting a dominant wavelength of between 550 nm and 570 nm, and the filter means is a (Roscolene) ROSCOLENE (TM) 874 or other filter having transmittance at 600 nm which is less than 5% of the transmittance at 550 nm.
Claim 8
Dependent Claim
20 words
An optoelectronic instrument as in claim 1, wherein said photodetectors are photodiodes having integral infrared filters covering their photoreceptive surfaces.
Claim 9
Dependent Claim
31 words
An optoelectronic instrument as in claim 2, wherein said plurality of LED members is mounted below said multiwell microplate and said plurality of photodetector members is mounted above said multiwell microplate.
Claim 10
Dependent Claim
111 words
An optoelectronic instrument as in claim 1, wherein said means for reversibly positioning said plurality of samples comprises a light-excluding door and an ejector mechanism, said door being a band of opaque flexible material adapted to slide in a channel, said channel extending partially around the lateral perimeter of said instrument and past an opening adapted to receive a sample plate containing said plurality of samples, said band being at least as long as said opening, said band having attached to its inner surface a means for contacting and activating said ejection mechanism when said door is opened, said ejection mechanism being adapted to eject said sample plate through said opening.
Claim 11
Dependent Claim
16 words
An optoelectronic instrument as in claim 9, wherein said opaque flexible material comprises fluorocarbon polymeric material.
Claim 12
Dependent Claim
219 words
An optoelectronic instrument as in claim 1, wherein the said signal in analog form from each said photodetector is attenuated by an attenuator device prior to being digitized by an analog-to-digital converter, said attenuation comprising the steps: a) obtaining the full scale analog current signal from each said LED-photodetector pair with said LED emitting light in the absence of sample; b) converting said full scale analog current signal to a full scale analog voltage signal by means of a current to voltage converter; c) applying said full scale analog voltage signal to said attenuator device; d) determining for each said LED-photodetector pair an attenuator constant such that the combination of said attenuator constant with said full scale analog voltage signal within said attenuator device produces a voltage output signal having a predetermined value less than but close to the maximum input signal for said analog to digital converter; e) storing each said attenuator constant corresponding to each said LED-photodetector pair in an attenuator table in a computer memory; f) restoring each said attenuator constant to said attenuator device when signal from said corresponding LED-photodetector pair is being measured; and g) combining each said signal with said corresponding restored attenuator constant within said attenuator device and passing the resulting output from said attenuator device to said analog to digital converter.
Claim 13
Dependent Claim
67 words
An optoelectronic instrument as in claim 1, wherein the light output from said LEDs is stabilized by applying a heating pulse at intervals between measuring pulses to each said LED to be stabilized, said heating pulses preferably having a power level, interval, and duration chosen such that the time average power of said heating pulses is approximately equal to the time average power of said measuring pulses.
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) | 1994-12-16 | 1995-06-17 | 1995-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-16 | 1999-06-17 | 1999-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-16 | 2003-06-17 | 2003-12-17 | $7700.00 | Window Closed / Lapsed |