Measuring Residual Lung Volume in Infants - Application: Assessments of lung volume in infants

An accurate assessment of lung volume in infants has been difficult to obtain. This discovery presents a novel, noninvasive technique to measure the residual lung volume (RV) by nitrogen (N2) washout with rapid thoracoabdominal compression in infants.

Despite being an unreliable volume landmark, the functional residual capacity (FRC) has remained the only lung volume that could be routinely measured in infants. This discovery has modified and validated the N2 washout technique and significantly increased its accuracy for measuring infant lung volumes. Using N2 washout, this discovery has for the first time, non-invasively measured, with a high precision and repeatability, the residual volume in infants. These studies also indicate that the RV will be an extremely reliable, routine and noninvasive quick measurement of this absolute lung volume and for defining lung growth in infants. Unlike the FRC, the RV is not influenced by dynamic events such as the infant's sleep state, airway caliber or the addition of dead space. Furthermore, this discovery is uniquely capable of precisely measuring the total lung capacity at V30 (TLC30) since it represents the sum of RV and FVC. Hence, as is the case in adults, RV/TLC30 ratio should be useful in evaluating diseases associated in its early stages with air trapping, such as asthma and cystic fibrosis.

The discovery can be used for routine clinical as well as research studies of lung function in infants from birth to three years of age. The nitrogen washout as well as similar other inert gases dilution/washout techniques such as SF6, Helium etc., will enhance 1) defining the normal development and growth of the lungs, 2) determining the efficacy of therapeutic interventions, and 3) evaluating the relation between lung injury in early life and chronic lung disease. Contrary to plethysmography, lung volume measurements by nitrogen washout can be done in sick or very small infants. Nitrogen washout is relatively simple and inexpensive to setup in the laboratory.

References:

"The open circuit nitrogen washout technique for measuring the lung volume in infants: methodological aspects", Thorax, September 1999.

"A novel non-invasive technique for measuring the residual lung volume by nitrogen washout with rapid thoracoabdominal compression in infants", Thorax, October 1999.

"The bias flow nitrogen washout technique for measuring the functional residual capacity in infants", Euro Respir J 2001; 17; 529-536

99-11

U.S. Patent #6,306,099

Related to 08-01 - U.S. Patent Application #11/985,416

Licensing Partner to commercialize this patented, medical invention

License Status: Available for Exclusive Licensing