Patent ID: 6306099
Filing Date: 2001-10-23
Classification: A61B

Abstract:
A method of measuring residual lung volume (RV) in an infant, comprising the steps of:(a) hyperventilating the infant by raising lung volume to a predetermined airway opening pressure until the respiratory drive is inhibited,(b) triggering rapid thoracoabdominal compression using an inflatable squeeze jacket on the infant before the end of the last passive expiration to induce a forced expiration down to the residual volume (RV),(c) maintaining thoracoabdominal compression during the pause in spontaneous respiration after the end of said last passive expiration while said respiratory drive is inhibited,(d) switching the infant's inspired air to 100% oxygen if using nitrogen washout or to a gaseous mixture containing a known concentration of an inert gas before the decline of the jacket pressure plateau and when the airflow and airway opening pressure are both zero,(e) terminating thoracoabdominal compression,(f) upon the resumption of spontaneous respiration by the infant, measuring the volume of the remaining gas in the infant's lungs by inert gas washout or dilution to calculate residual volume (RV).