US4011859A
Expired / Lapsed
US
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Method for continuously measuring the CO2 content in breathing gases
Assignee: Draegerwerk AG and Co KGaA
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Filing: 1975-09-02
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Granted: 1977-03-15
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Expires: 1995-09-02
Abstract
Abstract A method of continuously measuring the CO 2 content in breathing gases during inspiration and exhalation phases of breathing using a luminous source to pass infrared light rays through an interference filter accorded to CO 2 and a conduit of the gas to a photodetector, comprises passing the breathing gas developed during the breathing phases through the conduit to influence the photodetector to transmit a measured value signal in accordance with the CO 2 content, directing the signal to a breathing air phase recognition unit, storing the maxima and the minima of the measured value signals in each breathing phase in a maximum storage and a minimum storage, dividing the stored values under the control of the recognition unit and directing the values to a computation unit to indicate the logarithm of the values so as to give an indication of the variations of the CO 2 content. The indicated value is then directed to an indicating unit to show the value of the CO 2 .
Inventors
- 👤 Horst Frankenberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:58
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/35; G01N21/3504; A; A61; A61B; A61B5/00; A61B5/08; A61B5/083; A61B5/0836; A61B5/087; A61B5/0873; A61B5/72; A61B5/7235; A61B5/7239
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
136 words
A gas measuring method on the principle of infrared absorption for continuous measuring of the CO 2 content in breathing gases while using a measuring cell along with a luminous source, an interference filter accorded to CO 2 , and a photodetector, wherein the measured values of the measuring cell which is placed in the breathing-air stream are processed in a signal processing unit which is controlled by a breathing-air phase recognition unit, the respective maxima and minima of the measured values in each breathing phase are stored in a maximum-value storage and a minimum-value storage, said values, controlled by the breathing-air phase recognition unit, are divided and the logarithm is taken thereof in a computation unit and, since ##EQU6##the CO 2 content at the end of the expiration phase is indicated in an indicating unit.
Claim 2
Dependent Claim
136 words
A gas measuring method on the principle of infrared absorption for continuous measuring of the CO 2 content in breathing gases while using a measuring cell along with a luminous source, an interference filter accorded to CO 2 , and a photodetector, wherein the measured values of the measuring cell which is placed in the breathing-air stream are processed in a signal processing unit which is controlled by a breathing-air phase recognition unit, the respective maxima and minima of the measured values in each breathing phase are stored in a maximum-value storage and a minimum-value storage, said values, controlled by the breathing-air phase recognition unit, are divided and the logarithm is taken thereof in a computation unit and, since ##EQU6##the CO 2 content at the end of the expiration phase is indicated in an indicating unit.
Claim 3
Independent Claim
152 words
A method of continuously measuring CO 2 content in a breathing gas during the inspiration and exhalation phases of breathing and using a luminous source to pass light rays through an interference filter accorded to CO 2 and a conduit of the gas to a photodetector, comprising continuously passing the breathing gas developed during the breathing phases through a conduit to influence the photodetector to transmit a measured value signal in accordance with the CO 2 content, directing the signal to a breathing-air phase recognition unit, storing the maxima and the minima of the measured value signals in each breathing phase in a maximum storage and a minimum storage, dividing the stored values under the control of recognition unit and directing the values to a computation unit to indicate the logarithm of the values so as to give an indication of the variations of the CO 2 content in the breathing gases.
Claim 4
Independent Claim
152 words
A method of continuously measuring CO 2 content in a breathing gas during the inspiration and exhalation phases of breathing and using a luminous source to pass light rays through an interference filter accorded to CO 2 and a conduit of the gas to a photodetector, comprising continuously passing the breathing gas developed during the breathing phases through a conduit to influence the photodetector to transmit a measured value signal in accordance with the CO 2 content, directing the signal to a breathing-air phase recognition unit, storing the maxima and the minima of the measured value signals in each breathing phase in a maximum storage and a minimum storage, dividing the stored values under the control of recognition unit and directing the values to a computation unit to indicate the logarithm of the values so as to give an indication of the variations of the CO 2 content in the breathing gases.
Claim 5
Dependent Claim
37 words
A method according to claim 2, including indicating the CO 2 content in each breathing phase in an output terminal after division by the minimum value and the minimum value storage and logarithmation in the computing unit.
References Cited (Backward Citations)
US3811777A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-03-14 | 1980-09-13 | 1981-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-14 | 1984-09-13 | 1985-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-14 | 1988-09-13 | 1989-03-15 | $7700.00 | Window Closed / Lapsed |