DIGITAL DIRECT READING COLORIMETER
First Claim
1. In direct reading digital filter photometers for use in performing a plurality of chemical analyses of liquid samples, wherein the concentration of a specific constituent of a sample for each particular analysis is proportional to the intensity of radiant energy of a particular frequency range transmitted through a sample, the combination including:
- a source of radiant energy;
filter means for isolating a particular frequency range of radiant energy emitted from said source;
transducer means positioned to be responsive to said filtered radiant energy from said source and for generating a signal proportional to the intensity of said filtered radiant energy;
receptacle means for supporting a cuvette containing sample liquid to be analyzed in said path of radiant energy;
electrical digital readout means for providing a readout as a function of the intensity of said received radiant energy;
analog-digital computing circuit means for deriving and generating a signal proportional to the concentration of said constituent to be analyzed in said liquid;
assembly means comprising a plurality of electrical normalizing means comprising calibrated reference parameters for each constituent test, and a plurality of associated individual filter means;
each of said normalizing means being selectively electronically connectable with said computing circuit means for providing electrical reference parameters for said computing circuit means for constraining said readout means to provide a direct digital readout of the concentration of a specific constituent related to a particular analysis in response to the intensity of radiant intensity received from said source through a particular one of said filter means, each of said normalizing means being selectively connected with a particular one of said filter means; and
correlating means for selectively correlating said normalizing means with said readout means and said filter means for performing each said particular analysis. wherein said normalizing means include adjustable means for constraining said transducer means to respond to transmitted illumination through said individual filter means in the absence of said sample liquid in said path as if the total radiant energy transmitted by each said filter means is of substantially equal magnitude.
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Abstract
A combined blood constituent and prothrombin time analyzer is provided in which a plurality of removable and replaceable circuit modules are utilized to program the analyzer for appropriate light wavelength, reagent blank offset, scale factos and calibration parameters and which is self referencing to predetermined standards such that the results derived are all normalized for readout on a common digital readout device. The entire analyzer is contained in a compact console which includes controlled incubated storage for blood test samples together with insertion cavities for both constituent concentration and prothrombin time analysis. The results of each analysis are so normalized by the blood analyzer that a common digital counter can be used to convert these results to a numerical readout presentable on a common readout device and said results are substantially instantaneously displayed subsequent to initiation of any given test in the analyzer.
45 Citations
12 Claims
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1. In direct reading digital filter photometers for use in performing a plurality of chemical analyses of liquid samples, wherein the concentration of a specific constituent of a sample for each particular analysis is proportional to the intensity of radiant energy of a particular frequency range transmitted through a sample, the combination including:
- a source of radiant energy;
filter means for isolating a particular frequency range of radiant energy emitted from said source;
transducer means positioned to be responsive to said filtered radiant energy from said source and for generating a signal proportional to the intensity of said filtered radiant energy;
receptacle means for supporting a cuvette containing sample liquid to be analyzed in said path of radiant energy;
electrical digital readout means for providing a readout as a function of the intensity of said received radiant energy;
analog-digital computing circuit means for deriving and generating a signal proportional to the concentration of said constituent to be analyzed in said liquid;
assembly means comprising a plurality of electrical normalizing means comprising calibrated reference parameters for each constituent test, and a plurality of associated individual filter means;
each of said normalizing means being selectively electronically connectable with said computing circuit means for providing electrical reference parameters for said computing circuit means for constraining said readout means to provide a direct digital readout of the concentration of a specific constituent related to a particular analysis in response to the intensity of radiant intensity received from said source through a particular one of said filter means, each of said normalizing means being selectively connected with a particular one of said filter means; and
correlating means for selectively correlating said normalizing means with said readout means and said filter means for performing each said particular analysis. wherein said normalizing means include adjustable means for constraining said transducer means to respond to transmitted illumination through said individual filter means in the absence of said sample liquid in said path as if the total radiant energy transmitted by each said filter means is of substantially equal magnitude.
- a source of radiant energy;
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2. The invention defined in claim 1, wherein said normalizing means further includes compensating means selectively adjustable to vary said reference parameters to compensate for parametric variations in said sample liquids and variations in the spectral characteristics of said filter means.
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3. The invention defined in claim 1, wherein said normalizing means comprises a plurality of circuit modules, each including a given set of said reference parameters peculiar to a given analysis to be perFormed and selectively interconnected with said correlating means to effect a particular analysis;
- said adjustable means being comprised of at least one of said reference parameters in each said module the said one of said reference parameters being variable in magnitude.
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4. The invention defined in claim 3, wherein said normalizing means further includes compensating means selectively adjustable to vary other of said reference parameters to compensate for parametric variations in said sample liquids and variations in the spectral characteristics of said filter means.
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5. In a direct reading filter photometer for performing a plurality of chemical analyses of liquid samples irradiated by light of preselected wavelengths, including constituent concentration and prothrombin time analyses, the combination comprising:
- detector means responsive to the intensity of light transmitted through said samples and for providing outputs representative of said constituent concentration and prothrombin time values;
converter means for converting said outputs to digital signals representative thereof; and
display means for receiving said digital signals and converting same to direct numerical readouts of said constituent concentrations and prothrombin times; and
adjustable compensating means for selectively varying the response characteristics of said detector means to compensate for variations in the transmittance characteristics of said liquid samples, the spectral characteristics of said transmitted light and the total energy of said light irradiating said samples throughout the spectrum of said preselected wavelengths.
- detector means responsive to the intensity of light transmitted through said samples and for providing outputs representative of said constituent concentration and prothrombin time values;
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6. Testing means determining a particular constituent concentration in a liquid test sample irradiated by light of a preselected wave length comprising;
- a cavity for receiving a liquid test sample having a light path therethrough;
detector means for receiving light transmitted through said cavity with and without a liquid sample contained therein and providing first and second current signals proportional to the intensity of said transmitted light through an open and sample containing cavity, respectively;
amplifier means for receiving and converting said first current signal to a first output voltage representative of the light transmittance of said open cavity at a first conversion gain and receiving and converting said second current signal to a second output voltage representative of the light transmittance through said test sample at a second conversion gain, said gains having respective values such that said amplifier will produce equal output voltages for said open cavity and for the presence of a standard sample reagent blank in said cavity in place of said test sample;
converter means for receiving and converting said first and second output voltages to first and second time intervals, respectively, said time intervals being proportional to the respective logarithms of said first and second output voltages;
reference clock means;
counter means; and
control means interconnected with said converter means, said reference clock means and said counter means enabling said converter means to initiate said time intervals and gating said clock means into said counter means at the beginning of and throughout said time intervals;
said control means including selecting means for constraining said counter to count to opposite directions over said first and second time intervals, to subtract one count from the other, whereby the difference in the said counts is representative of the said particular constituent concentration in said test sample; and
wherein said amplifier means includes compensating means for selectively varying said first conversion gain to compensate for variations in the transmittance of total light energy through said open cavity at various preselected wavelengths to maintain said first output voltage substantially uniform throughout a spectrum of selected wavelengths.
- a cavity for receiving a liquid test sample having a light path therethrough;
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7. The invention defined in claim 6, wherein said amplifier means further includes second compensating means for selectively varying said second conversion gain to compensate for variations in the transmittance characteristics of said standard sample reagent blank.
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8. The invention defined in claim 6, wherein said reference clock means comprises a variable frequency oscillator;
- and wherein said testing means further comprises correlating means for constraining said oscillator to a particular clock frequency for each particular constituent concentration test performed by said testing means;
said correlating means further including frequency compensating means for selectively varying said particular clock frequency to compensate for spectral variations in said light transmitted through said cavity.
- and wherein said testing means further comprises correlating means for constraining said oscillator to a particular clock frequency for each particular constituent concentration test performed by said testing means;
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9. The invention defined in claim 7, wherein said reference clock means comprises a variable frequency oscillator;
- and wherein said testing means further comprises correlating means constraining said oscillator to a particular clock frequency for each particular constituent concentration test performed by said testing means;
said correlating means further including frequency compensating means selectively varying said particular clock frequency to compensate for spectral variations in said light transmitted through said cavity.
- and wherein said testing means further comprises correlating means constraining said oscillator to a particular clock frequency for each particular constituent concentration test performed by said testing means;
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10. Testing means determining a particular constituent concentration in a liquid test sample irradiated by light of a preselected wave length comprising:
- a cavity for receiving a liquid test sample having a light path therethrough;
detector means for receiving light transmitted through said cavity with and without a liquid sample contained therein and providing first and second current signals proportional to the intensity of said transmitted light through an open and sample containing cavity, respectively;
amplifier means for receiving and converting said first current signal to a first output voltage representative of the light transmittance of said open cavity at a first conversion gain and for receiving and converting said second current signal to a second output voltage representative of the light transmittance through said test sample at a second conversion gain, said gains having respective values such that said amplifier will produce equal output voltages for said open cavity and for the presence of a standard sample reagent blank in said cavity in place of said test sample;
converter means for receiving and converting said first and second output voltages to first and second digital signals, respectively; and
computer means for receiving and determining the difference in magnitude of said digital signals;
said difference representing the particular constituent concentration in said test sample; and
wherein said amplifier means includes manually adjustable compensating means selectively varying said first conversion gain to compensate for variations in the transmittance of total light energy through said open cavity at various preselected wavelengths to maintain said first output voltage substantially uniform throughout a spectrum of selected wavelengths.
- a cavity for receiving a liquid test sample having a light path therethrough;
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11. The invention defined in claim 10, wherein said amplifier means further includes second manually adjustable compensating means for selectively varying said second conversion gain to compensate for variations in the transmittance characteristics of said standard sample reagent blank.
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12. Testing means determining a particular constituent concentration in a liquid test sample irradiated by light of a preselected wave length comprising:
- a cavity for receiving a liquid test sample having a light path therethrough;
detector means for receiving light transmitted through said cavity with and without a liquid sample contained therein and providing first and second current signals proportional to the intensity of said transmitted light through an open and sample containing cavity, respectively;
amplifier means for receiving and converting said first current signal to a first output voltage representative of the light transmittance of said open cavity at a first conversion gain and for receiving and converting said second current signal to a second output voltage representative of the light transmittance through said test sample at a second conversion gain, said gains having respective values such that said amplifier will produce equal output voltages for said open cavity and for the presence of a standard sample reagent blank in said cavity in place of said test sample;
converter means for receiving and converting said first and second output voltages to first and second digital signals, respectively;
computer means for receiving and determining the difference in magnitude of said digital signals;
said difference representing the particular constituent concentration in said test sample;
said testing means further includes a reference circuit module for each test to be performed, each said module including circuit means for defining a plurality of standard reference parameters peculiar to the test to which said module relates; and
switching means selectively interconnecting said modules with said amplifier means and said converter means such that said standard reference parameters constrain said amplifier means and said converter means to modify said gain values and said digital signals and thereby normalize said testing means to the specific test being performed;
said standard reference parameters being selectively variable to compensate for variations in the spectral characteristics of said transmitted light and the transmittance characteristics of the said standard sample reagent blank for each said specific test and to provide substantially uniform response in each said test of said amplifier means to said open cavity over the spectrum of said preselected wavelengths.
- a cavity for receiving a liquid test sample having a light path therethrough;
Specification