Biomaterial Database

Computer analysis of the single-breath nitrogen washout curve. 1976

N Craven, and G Sidwall, and P West, and D S McCarthy, and R M Cherniack

A computerized system has been developed to analyze the parameters that can be derived from the nitrogen washout curve. Analog signals for air flow, volume, and nitrogen concentration are entered either on-line or off-line into a 24,000 mini-computer. The program calculates vital capacity, total lung capacity, and residual volume, as well as the slope of phase III, closing volume in liters, total lung capacity, residual volume, closing capacity, closing volume/vital capacity ratio, and closing capacity/total lung capacity ratio. Validation tests showed excellent correlation between hand- and computer-calculated values of closing volume(r=0.864), vital capacity (r=0.997), total lung capacity (r=0.991), and slope of phase III (R=0.926). We concluded that the computerized system for analysis of the expired nitrogen washout curve is as reliable as hand calculations and is immeasurably faster.

UI	MeSH Term	Description	Entries
D008176	Lung Volume Measurements	Measurement of the amount of air that the lungs may contain at various points in the respiratory cycle.	Lung Capacities,Lung Volumes,Capacity, Lung,Lung Capacity,Lung Volume,Lung Volume Measurement,Measurement, Lung Volume,Volume, Lung
D009584	Nitrogen	An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.
D012115	Residual Volume	The volume of air remaining in the LUNGS at the end of a maximal expiration. Common abbreviation is RV.	Residual Volumes,Volume, Residual,Volumes, Residual
D012123	Pulmonary Ventilation	The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.	Respiratory Airflow,Ventilation Tests,Ventilation, Pulmonary,Expiratory Airflow,Airflow, Expiratory,Airflow, Respiratory,Test, Ventilation,Tests, Ventilation,Ventilation Test
D003936	Diagnosis, Computer-Assisted	Application of computer programs designed to assist the physician in solving a diagnostic problem.	Computer-Assisted Diagnosis,Computer Assisted Diagnosis,Computer-Assisted Diagnoses,Diagnoses, Computer-Assisted,Diagnosis, Computer Assisted
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014797	Vital Capacity	The volume of air that is exhaled by a maximal expiration following a maximal inspiration.	Forced Vital Capacity,Capacities, Forced Vital,Capacities, Vital,Capacity, Forced Vital,Capacity, Vital,Forced Vital Capacities,Vital Capacities,Vital Capacities, Forced,Vital Capacity, Forced