Method of correcting componential concentration in expiration and expiration analyzer
First Claim
1. A method of correcting componential concentration in expiration, comprising the steps of:
- analyzing an expiration sample of alveolar air, being mixed with at least one of air from a dead space and ambient air, for obtaining a measured value of a target component;
measuring at least one of O2 gas concentration and CO2 gas concentration as a standard gas concentration in said expiration sample; and
correcting said measured value of said target component by a measured value of said standard gas concentration in said expiration sample with reference to a standard gas concentration in end-tidal air.
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Accused Products
Abstract
A first sample measuring passage provided between a collection port and a suction pump has a sample gas measurer for measuring expiration components, while a second sample measuring passage which is provided in parallel with the first sample measuring passage has a standard gas measurer for measuring O2 gas. Assuming that [A] represents a measured value of a target component in an expiration sample and [b1 ] represents O2 concentration in the expiration sample, correction is made on the basis of:
[M]=f.sub.1 ·(21-[a.sub.1 ]) [A]/(21-[b.sub.1 ])
where [M] represents the corrected measured value of the target component, [a1 ] represents O2 concentration in end-tidal air which is supplied as a constant such as 15.3, for example, and f1 represents an experimentally prescribed coefficient such as 1.67, for example.
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Citations
10 Claims
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1. A method of correcting componential concentration in expiration, comprising the steps of:
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analyzing an expiration sample of alveolar air, being mixed with at least one of air from a dead space and ambient air, for obtaining a measured value of a target component; measuring at least one of O2 gas concentration and CO2 gas concentration as a standard gas concentration in said expiration sample; and correcting said measured value of said target component by a measured value of said standard gas concentration in said expiration sample with reference to a standard gas concentration in end-tidal air. - View Dependent Claims (2, 3, 4, 5)
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6. An expiration analyzer comprising:
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a first sample measuring passage means, having a sample gas measurer which measures at least one or two components in expiration, for receiving from a collection port an expiration sample of alveolar air being mixed with at least one of air from a dead space and ambient air; a second sample measuring passage means, having a standard gas measurer which measures at least one of O2 gas and CO2 gas as standard gas and being provided in parallel with said first sample measuring passage means, for receiving from said collection port said expiration sample being identical to that guided in said first sample measuring passage means; a heating means for heating passages between said collection port and said sample and standard gas measurers; and a computing means for correcting a componential measured value in said expiration sample, being measured by said sample gas measurer, by a measured value of said standard gas concentration in said expiration sample, being measured by said standard gas measurer, with reference to concentration of a standard gas in end-tidal air. - View Dependent Claims (7, 8, 9, 10)
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Specification