Patent US3576558A successfully refreshed from Google Patents.
US3576558A
Expired / Lapsed
US
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Opacity comparison apparatus and method
Assignee: University of Utah
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Filing: 1968-05-14
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Granted: 1971-04-27
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Expires: 1988-05-14
Abstract
Abstract An apparatus and method for detecting the reduction of light transmitting capability of a fluid being monitored by passing radiation through both the monitored fluid and a reference fluid and comparing the intensity of the radiation emerging from each. When the relative opacity or transparency of the monitored fluid reaches a predetermined level, a signal is generated which is amplified and converted to a detectable warning.
Inventors
- 👤 Kenneth L Devries
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:11
CPC Classifications
A; A61; A61M; A61M1/00; A61M1/14; A61M1/16; A61M1/1692; G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/53; G01N21/534
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
245 words
In a device for detecting a predetermined concentration of relatively opaque particles in a test fluid comprising first means containing a reference fluid and second means containing a test fluid, means continuously displacing the test fluid through the second containing means, means to project radiation simultaneously through the reference fluid and the continuously flowing test fluid in the first and second containing means, respectively, means to continuously monitor the individual intensity of the radiation emerging from each fluid and convert the radiation to an electronic signal, said monitor means comprising spaced photosensitive means comprising one terminal at ground potential and another terminal at a negative potential, and the other photosensitive means comprising one terminal at ground potential and another terminal at a positive potential, the ground potential normally having a value such that the voltage difference between ground and the positive potential is essentially the same as the voltage difference between ground and the negative potential, the positive and negative potentials being supplied to a voltage summation point across resistors, at least one of which is adjustable to normally balance the opposed potentials the electronic signal emanating from the voltage summation point, circuit means responsive to the electronic signal to trigger an alarm circuit only when the intensity of the radiation emerging from the test fluid differs more than a threshold magnitude from the radiation emerging from the reference fluid, and alarm means responsive to the triggered alarm circuit to emit a detectable warning signal.
Claim 2
Dependent Claim
245 words
In a device for detecting a predetermined concentration of relatively opaque particles in a test fluid comprising first means containing a reference fluid and second means containing a test fluid, means continuously displacing the test fluid through the second containing means, means to project radiation simultaneously through the reference fluid and the continuously flowing test fluid in the first and second containing means, respectively, means to continuously monitor the individual intensity of the radiation emerging from each fluid and convert the radiation to an electronic signal, said monitor means comprising spaced photosensitive means comprising one terminal at ground potential and another terminal at a negative potential, and the other photosensitive means comprising one terminal at ground potential and another terminal at a positive potential, the ground potential normally having a value such that the voltage difference between ground and the positive potential is essentially the same as the voltage difference between ground and the negative potential, the positive and negative potentials being supplied to a voltage summation point across resistors, at least one of which is adjustable to normally balance the opposed potentials the electronic signal emanating from the voltage summation point, circuit means responsive to the electronic signal to trigger an alarm circuit only when the intensity of the radiation emerging from the test fluid differs more than a threshold magnitude from the radiation emerging from the reference fluid, and alarm means responsive to the triggered alarm circuit to emit a detectable warning signal.
Claim 3
Dependent Claim
21 words
In a device as defined in claim 1 wherein said test fluid comprises a dialysate solution circulated from an artificial kidney.
Claim 4
Dependent Claim
209 words
In a device for detecting a predetermined concentration of relatively opaque particles in a test fluid comprising first means containing a reference fluid and second means containing a test fluid, means continuously displacing the test fluid through the second containing means, means to project radiation simultaneously through the reference fluid and the continuously flowing test fluid in the first and second containing means, respectively, means to continuously monitor the individual intensity of the radiation emerging from each flUid and convert the radiation to an electronic signal, circuit means responsive to the electronic signal to trigger an alarm circuit only when the intensity of the radiation emerging from the test fluid differs more than a threshold magnitude from the radiation emerging from the reference fluid, and alarm means responsive to the triggered alarm circuit to emit a detectable warning signal, said circuit means comprise a solid state amplifier provided with (1) a signal inverting input means to receive signals from the detecting means and invert the signals to be amplified, and (1) signal noninverting input means to accommodate reamplification of the first amplified signals without again inverting the signals and time delay means interposed between the amplifier and the noninverting input means to inhibit inadvertent triggering of the alarm circuit.
Claim 5
Dependent Claim
209 words
In a device for detecting a predetermined concentration of relatively opaque particles in a test fluid comprising first means containing a reference fluid and second means containing a test fluid, means continuously displacing the test fluid through the second containing means, means to project radiation simultaneously through the reference fluid and the continuously flowing test fluid in the first and second containing means, respectively, means to continuously monitor the individual intensity of the radiation emerging from each flUid and convert the radiation to an electronic signal, circuit means responsive to the electronic signal to trigger an alarm circuit only when the intensity of the radiation emerging from the test fluid differs more than a threshold magnitude from the radiation emerging from the reference fluid, and alarm means responsive to the triggered alarm circuit to emit a detectable warning signal, said circuit means comprise a solid state amplifier provided with (1) a signal inverting input means to receive signals from the detecting means and invert the signals to be amplified, and (1) signal noninverting input means to accommodate reamplification of the first amplified signals without again inverting the signals and time delay means interposed between the amplifier and the noninverting input means to inhibit inadvertent triggering of the alarm circuit.
Claim 6
Dependent Claim
188 words
In an apparatus for detecting a critical relative opacity of a fluid comprising: a photoelectric cell situated to operatively detect radiation passing through a reference fluid of predetermined opacity such that a reference input signal having a predetermined polarity is developed; a photoelectric cell situated to operatively detect radiation passing through a volume of moving test fluid to generate a test input signal normally having a polarity opposite the reference input signal and a magnitude slightly greater than the reference input signal; circuit elements to combine the reference and test signals so that a single signal having the polarity of the test signal normally results; an amplifier adapted to amplify the resulting signal silicon controlled rectifier means receiving the resulting signal and issuing an output signal only after a turn on threshold voltage is received; and an alarm circuit electrically connected with the silicon controlled rectifier means and responsive exclusively to the output signal from the silicon controlled rectifier means to generate a detectable alarm only when the opacity of the test fluid is sufficiently greater than the opacity of the reference fluid that the reference signal dominates.
Claim 7
Dependent Claim
188 words
In an apparatus for detecting a critical relative opacity of a fluid comprising: a photoelectric cell situated to operatively detect radiation passing through a reference fluid of predetermined opacity such that a reference input signal having a predetermined polarity is developed; a photoelectric cell situated to operatively detect radiation passing through a volume of moving test fluid to generate a test input signal normally having a polarity opposite the reference input signal and a magnitude slightly greater than the reference input signal; circuit elements to combine the reference and test signals so that a single signal having the polarity of the test signal normally results; an amplifier adapted to amplify the resulting signal silicon controlled rectifier means receiving the resulting signal and issuing an output signal only after a turn on threshold voltage is received; and an alarm circuit electrically connected with the silicon controlled rectifier means and responsive exclusively to the output signal from the silicon controlled rectifier means to generate a detectable alarm only when the opacity of the test fluid is sufficiently greater than the opacity of the reference fluid that the reference signal dominates.
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) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |