Variability study of simulating plethysmographic measurements in pulmonary function studies

摘要

Chest wall mobility assessment is an important parameter in diagnosing pulmonary disorders. The purpose of this study is to examine and compare variations in thoracic and abdominal volumes based on changes in chest expansion that can be used as a clinical tool in pulmonary function studies. A newly proposed optical camera system utilizing a set of markers placed on subjects' thoracic and abdominal compartments is used to examine lung volume variations in these areas. This technique is complemented by body plethysmography and anthropometric measurement methods as a supplemental reference for comparative purposes to estimate lung volume variation in the thoraco-abdominal compartments. Extensive proprietary software code was developed to analyze captured video frames and track the changing shapes of the thoracic and abdominal compartments, which results in the differential lung volume variations. For the purpose of this study, lung volume variations are computed based on the cylindrical models of the thoracic and abdominal compartments. Ten test subjects, seven male and three female, participated in measurements for all three techniques. The photographic method of computing differential lung volume variations based on standard video images is non-invasive and inexpensive, and high-quality images are obtained under optimized lighting conditions.