A multiuser system for whole body plethysmographic measurements and interpretation

A multiuser system for whole body plethysmographic measurements and interpretation which has been developed under clinical conditions is described. The following measurements can be carried out in a rapid way and in one session with the patient: specific airway resistance during spontaneous breathing, determination of functional residual capacity, static lung volumes, and maximal forced expiratory data. Each section is normally measured twice and can be repeated up to ten times. The final results are displayed and printed together with a consistent system of normal reference values. All values and selected original curves are stored automatically in an integrated data base system. Obstructive patients are measured again after the inhalation of a bronchodilator. All results are evaluated by an automatic interpretation program. This analyzes and graduates airway obstruction, lung volumes, and pharmacological airway reversibility using standardized texts which are written below all numerical printouts and graphical plots. The interpretation algorithm is tree structured and uses the normal reference values as a knowledge base. The system supports up to four online laboratories with their own A/D converter and up to 20 video terminals, printers, plotters, and modems. Our laboratory performs 8,297 such complete measurements on 4,671 different patients per year with one body box.