Biomaterial Database

Expiratory flow limitation. 1983

R E Hyatt

The first major advance in understanding expiratory flow limitation of the lungs came with the description of isovolume pressure-flow curves. These curves documented the existence of a volume-dependent limit to maximal expiratory flow and led directly to the description of the maximal expiratory flow-volume (MEFV) curve. Definitive modeling of flow limitation awaited the description of a localized mechanism that dominated the flow-limiting process. The phenomenon of wave speed limitation of flow was shown to apply to the airways and provided the needed localized mechanism. Using this concept and recent data on airway mechanics and the frictional losses in the flow, a computational model of the MEFV curve has been developed. Further progress will require modeling of inhomogeneous emptying in diseased lungs, perfecting noninvasive techniques of estimating pertinent airway characteristics, and improving techniques for increasing the signal-to-noise ratio in MEFV curves.

UI	MeSH Term	Description	Entries
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D008171	Lung Diseases	Pathological processes involving any part of the LUNG.	Pulmonary Diseases,Disease, Pulmonary,Diseases, Pulmonary,Pulmonary Disease,Disease, Lung,Diseases, Lung,Lung Disease
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
D008449	Maximal Expiratory Flow-Volume Curves	Curves depicting MAXIMAL EXPIRATORY FLOW RATE, in liters/second, versus lung inflation, in liters or percentage of lung capacity, during a FORCED VITAL CAPACITY determination. Common abbreviation is MEFV.	Maximal Expiratory Flow Volume Curves
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
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
D005540	Forced Expiratory Flow Rates	The rate of airflow measured during a FORCED VITAL CAPACITY determination.	Expiratory Forced Flow Rates,Flow Rates, Expiratory Forced,Flow Rates, Forced Expiratory
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