Cardiopulmonary exercise testing apparatus and method
First Claim
1. A method for calibrating a gas analysis apparatus having one or more gas analyzers, comprising the steps of:
- providing a compression bottle having at least one valve;
pressurizing the compression bottle with calibration gas of known composition;
opening the valve such that the calibration gas is abruptly expelled from the compression bottle with a flow rate and pressure profile over its outflow from the compression bottle similar to an exhaled human breath;
measuring the calibration gas with the one or more gas analyzers;
sensing the flow rate of the calibration gas out of the compression bottle; and
calculating a set of calibration constants; and
storing the calibration constants in a computing means.
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Accused Products
Abstract
A gas analysis apparatus, and a method for calibrating it and for compensating measurement errors, are disclosed. This method and apparatus are particularly suited for use during a cardiopulmonary exercise test by a test subject. The oxygen and carbon dioxide concentrations of the subject'"'"'s breath are measured, and errors are compensated based on the results of previous calibration. These compensated measurements, as well as other physiological data monitored during the cardiopulmonary exercise test and quantities calculated from these measurements, are presented as a series of graphs in a logical order to enhance their diagnostic and prognostic value. A facemask and headstraps are adapted for use with the gas analysis apparatus. The facemask possesses a plurality of pins fitting into corresponding holes in the headstraps, and the headstraps possess quick-release attachment means to provide for quickly securing the face mask to or removing it from a subject.
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Citations
7 Claims
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1. A method for calibrating a gas analysis apparatus having one or more gas analyzers, comprising the steps of:
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providing a compression bottle having at least one valve;
pressurizing the compression bottle with calibration gas of known composition;
opening the valve such that the calibration gas is abruptly expelled from the compression bottle with a flow rate and pressure profile over its outflow from the compression bottle similar to an exhaled human breath;
measuring the calibration gas with the one or more gas analyzers;
sensing the flow rate of the calibration gas out of the compression bottle; and
calculating a set of calibration constants; and
storing the calibration constants in a computing means. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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6. The method of claim 5, wherein the measuring the time t1 step occurs when the flow measurement means detects outflow from the compression bottle above a preset threshold level, wherein the measuring the time t2 step occurs for each gas analyzer when the concentration of calibration gas within it rises above a preset threshold level, and further comprising the step after the calculating a slope and offset step of interpolating the actual values of t1 and t2 for each gas analyzer utilizing the corresponding calculated SlopeGas value for that gas analyzer.
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7. The method of claim 1, further comprising the step before the opening step of purging the gas analysis apparatus with ambient air.
Specification