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CA2000303A1
Expired / Lapsed
CA
⏱️ 0.0 years remaining
Oxygen sensor using phase shift
Assignee: Smiths Medical ASD Inc
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Filing: 1989-10-06
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Granted: —
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Expires: 2009-10-06
Abstract
Abstract Oxygen Sensor Using Phase-Shift Abstract of the Disclosure A phosphorescent sensor is subjected to a fluid containing oxygen. A light source modulated with a sine wave excites the sensor thereby producing an emitted light having a sine wave. The phase-shift between the exciting and emitted light source is compared, the phase-shift being a measure of the pressure of the oxygen.
Inventors
- 👤 Robert C. Davis
- 👤 Warren B. Nicholson
- 👤 Russell H. Barnes
Bibliographic Details
Application Number
—
Jurisdiction
CA
Data Source
google_patents
Last Synchronized
2026-11-03 20:00
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/6408; A; A61; A61B; A61B5/00; A61B5/145; A61B5/1455; A61B5/1459; A61B5/1495
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
78 words
Apparatue for measuring partial pressure of oxygen in a fluid comprising, a sensor which, when excited ted at a first wavelength, produces an emission at a second wave-length, means for exciting said sensor with a sine wave modulated light source to produce an emitted light, means for comparing the phase shift of said emitted light with respect to the references sine wave of said excitation light, the amount of phase-shift forming a measure of partial pressure of O2.
Claim 2
Dependent Claim
78 words
Apparatue for measuring partial pressure of oxygen in a fluid comprising, a sensor which, when excited ted at a first wavelength, produces an emission at a second wave-length, means for exciting said sensor with a sine wave modulated light source to produce an emitted light, means for comparing the phase shift of said emitted light with respect to the references sine wave of said excitation light, the amount of phase-shift forming a measure of partial pressure of O2.
Claim 3
Dependent Claim
141 words
Apparatus for measuring partial pressure of oxygen in blood comprising, an optical fiber having a sensor on one end thereof, a substantially monochromatic light source, means connected to said light source for modulating said light source with a sine wave, means for focusing said light source on the other end of said fiber, whereby said light source will excite said sensor to emit an emitted light modulated with said sine wave, a photodetector positioned to receive said emitted light for converting said light to a sine wave voltage, a phase comparator, means connecting said modulating means and said photodetector to said phase comparator to compare the phase shift of said emitted light to the modulat-ing wave, and display means connected to said phase comparator for receiving the output of said phase comparator and displaying said output as a partial oxygen pressure.
Claim 4
Dependent Claim
141 words
Apparatus for measuring partial pressure of oxygen in blood comprising, an optical fiber having a sensor on one end thereof, a substantially monochromatic light source, means connected to said light source for modulating said light source with a sine wave, means for focusing said light source on the other end of said fiber, whereby said light source will excite said sensor to emit an emitted light modulated with said sine wave, a photodetector positioned to receive said emitted light for converting said light to a sine wave voltage, a phase comparator, means connecting said modulating means and said photodetector to said phase comparator to compare the phase shift of said emitted light to the modulat-ing wave, and display means connected to said phase comparator for receiving the output of said phase comparator and displaying said output as a partial oxygen pressure.
Claim 5
Dependent Claim
21 words
Apparatus as in claim 2 further comprising, phase adjust means for providing a zero phase-shift when said sensor detects 100% oxygen.
Claim 6
Dependent Claim
12 words
Apparatus as in claim 1 in which said sensor is a phosphor.
Claim 7
Dependent Claim
22 words
Apparatus as in claim 1 in which said sensor is a phosphor and is excited at a frequency of about 1000 Hz.
Claim 8
Independent Claim
97 words
The method of measuring the pressure of oxygen in a fluid using a sensor that emits light of one frequency when excited by light of another fre-quency and whose emission is quenched by the presence of oxygen comprising the steps of, placing said sensor in said fluid, modulating a light source with a sine wave, exciting said sensor with said modulated light source, thereby generating an emitted light modulated by said sine wave, measuring the phase difference between the sine wave of said source light and said emitted light, and converting said phase different to oxygen pressure.
Claim 9
Independent Claim
97 words
The method of measuring the pressure of oxygen in a fluid using a sensor that emits light of one frequency when excited by light of another fre-quency and whose emission is quenched by the presence of oxygen comprising the steps of, placing said sensor in said fluid, modulating a light source with a sine wave, exciting said sensor with said modulated light source, thereby generating an emitted light modulated by said sine wave, measuring the phase difference between the sine wave of said source light and said emitted light, and converting said phase different to oxygen pressure.
References Cited (Backward Citations)
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