Dynamic metabolism monitoring system
First Claim
1. A metabolism monitor comprising:
- a chamber;
said chamber further comprisingan inlet connected to ambient air to allow said ambient air to enter the chamber,an outlet to allow the chamber air to leave the chamber to said ambient air,wherein the chamber is further adapted to connect to a respiration of a subject;
a gas analyzer configured to measure chamber air characteristics;
an air flow sensor connected to the inlet or the outlet to measure chamber air flow; and
an estimator including a predictor and a corrector, the estimator configured to initialize values of subject variables and of chamber variables,wherein the subject variables comprise a subject oxygen consumption flow rate and a subject carbon dioxide production flow rate, and the chamber variables comprise chamber air levels of oxygen and of carbon dioxide;
wherein at each of a plurality of times, the monitor;
measures chamber air characteristics, using the gas analyzer, to determine measurement variables, said measurement variables comprising measured chamber air levels of oxygen and of carbon dioxide;
measures chamber air flow, using the air flow sensor, to determine values of the air flow entering the chamber, when the air flow sensor is connected to the inlet, or the values of the air flow exiting the chamber, when the air flow sensor is connected to the outlet;
generates, using the predictor, the values of anticipated subject variables and of anticipated chamber variables in response to values of subject variables, values of chamber variables, and the measured chamber air flow; and
corrects, using the corrector, the values of the subject variables and of the chamber variables in response to the values of the measurement variables, the values of the anticipated subject variables, and the values of the anticipated chamber variables; and
whereupon a subject metabolism is monitored in response to the values of the corrected subject variables.
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Accused Products
Abstract
A metabolism monitoring system, data analyzer, and method is disclosed for processing data to very quickly estimate metabolic parameters. The analyzer of the invention uses a dynamic observer state estimator to estimate the parameters and tracks their values as they change with alterations in the patient metabolism or testing conditions. The state estimator does not use the conventional steady state solutions. The observer predicts the patient consumption of oxygen and exhalation of carbon dioxide at a subsequent point in time, corrects these values using measurements of air flow rate and chamber levels of oxygen and carbon dioxide taken at that subsequent time, and repeats for the next time. The corrected values are used for estimation of the metabolic parameters.
2 Citations
14 Claims
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1. A metabolism monitor comprising:
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a chamber;
said chamber further comprisingan inlet connected to ambient air to allow said ambient air to enter the chamber, an outlet to allow the chamber air to leave the chamber to said ambient air, wherein the chamber is further adapted to connect to a respiration of a subject; a gas analyzer configured to measure chamber air characteristics; an air flow sensor connected to the inlet or the outlet to measure chamber air flow; and an estimator including a predictor and a corrector, the estimator configured to initialize values of subject variables and of chamber variables, wherein the subject variables comprise a subject oxygen consumption flow rate and a subject carbon dioxide production flow rate, and the chamber variables comprise chamber air levels of oxygen and of carbon dioxide; wherein at each of a plurality of times, the monitor; measures chamber air characteristics, using the gas analyzer, to determine measurement variables, said measurement variables comprising measured chamber air levels of oxygen and of carbon dioxide; measures chamber air flow, using the air flow sensor, to determine values of the air flow entering the chamber, when the air flow sensor is connected to the inlet, or the values of the air flow exiting the chamber, when the air flow sensor is connected to the outlet; generates, using the predictor, the values of anticipated subject variables and of anticipated chamber variables in response to values of subject variables, values of chamber variables, and the measured chamber air flow; and corrects, using the corrector, the values of the subject variables and of the chamber variables in response to the values of the measurement variables, the values of the anticipated subject variables, and the values of the anticipated chamber variables; and whereupon a subject metabolism is monitored in response to the values of the corrected subject variables. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method to monitor a metabolism of a subject including the steps of:
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connecting, via an inlet, a chamber to ambient air to allow said ambient air to enter the chamber, and, via an outlet, the chamber to ambient air to allow chamber air to leave the chamber to said ambient air, wherein the chamber is further adapted to connect to a respiration of the subject; providing a gas analyzer configured to measure chamber air characteristics; providing an air flow sensor connected to the inlet or the outlet and configured to measure chamber air flow; and providing an estimator including a predictor and a corrector, the estimator configured to initialize values of subject variables and of chamber variables, wherein the subject variables comprise a subject oxygen consumption flow rate and a subject carbon dioxide production flow rate, and the chamber variables comprise chamber air levels of oxygen and of carbon dioxide wherein at each of a plurality of times the monitor goes through the steps of; measuring chamber air characteristics, using the gas analyzer, to determine measurement variables, said measurement variables comprising measured chamber air levels of oxygen and of carbon dioxide; measuring chamber air flow, using the air flow sensor, to determine values of the air flow entering the chamber, when the air flow sensor is connected to the inlet, or the values of the air flow exiting the chamber, when the air flow sensor is connected to the outlet; generating, using the predictor, the values of anticipated subject variables and of anticipated chamber variables in response to values of subject variables, values of chamber variables, and the measured chamber air flow; and correcting, using the corrector, the values of the subject variables and of the chamber variables in response to the values of the measurement variables, the values of the anticipated subject variables, and the values of the anticipated chamber variables; and whereupon a subject metabolism is monitored in response to the values of the corrected subject variables. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification