Nitric oxide measurements in patients using flowfeedback
First Claim
Patent Images
1. A method performed by a nitric oxide (NO) monitoring system of determining exhaled nitric oxide (FENO) from a patient, the method comprising:
- collecting, by a patient breathing circuit, exhaled gases from the patient;
measuring an exhalation flow rate of the exhaled gases as a function of time;
determining an average exhalation flow rate of the exhaled gases based on the measured exhalation flow rate as a function of time;
calculating a baseline correction factor that is a function of the measured FeNO concentration at the average exhalation flow rate and an FeNO concentration for a healthy person at the average exhalation flow rate;
normalizing the measured FeNO concentration using the baseline correction factor to obtain a normalized FeNO;
adjusting the normalized FeNO to a selected flow rate; and
scaling back the normalized FeNO using the baseline correction factor to determine the FeNO of the patient.
2 Assignments
0 Petitions
Accused Products
Abstract
The present invention provides a method for measuring FeNO in a subject, wherein the FeNO data derived from a subject patient is normalized to compensate for variations of FeNO with flow rate.
-
Citations
13 Claims
-
1. A method performed by a nitric oxide (NO) monitoring system of determining exhaled nitric oxide (FENO) from a patient, the method comprising:
-
collecting, by a patient breathing circuit, exhaled gases from the patient; measuring an exhalation flow rate of the exhaled gases as a function of time; determining an average exhalation flow rate of the exhaled gases based on the measured exhalation flow rate as a function of time; calculating a baseline correction factor that is a function of the measured FeNO concentration at the average exhalation flow rate and an FeNO concentration for a healthy person at the average exhalation flow rate; normalizing the measured FeNO concentration using the baseline correction factor to obtain a normalized FeNO; adjusting the normalized FeNO to a selected flow rate; and scaling back the normalized FeNO using the baseline correction factor to determine the FeNO of the patient. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A nitric oxide (NO) monitoring system comprising:
-
at least one processor; and at least one memory, communicatively coupled to the at least one processor and storing instructions that, when executed by the processor, cause the NO monitoring system to perform a method of determining exhaled nitric oxide (FeNO) for a subject, the method comprising; collecting exhaled gases from the subject; measuring FeNO in the collected exhaled gases; measuring a flow rate of the exhaled gases as a function of time; determining an average flow rate of the exhaled gases based on the measured flow rate of exhaled gases as a function of time; calculating a baseline correction factor “
X”
according to the formula;X=A/B where A is the measured FeNO at the average flow rate; and
B is FeNO for a normal subject at the average flow rate;normalizing the measured FeNO using the baseline correction factor X to obtain a normalized FeNO; adjusting the normalized FeNO to a selected flow rate; and scaling back the normalized FeNO using the baseline correction factor; thereby determining FeNO for the subject. - View Dependent Claims (10, 11, 12, 13)
-
Specification