Uneven Ventilation as a Continuous Distribution Function of Alveolar Dilution.
Interim rept. Jun 68-Dec 69,
SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TEX
Pagination or Media Count:
Replicate nitrogen washout curves recorded in 10 normal subjects were analyzed both by the classical Fowler model and by a model which treats the alveolar dilution ratio as being a continuously distributed variable. The majority of the curves could be satisfactorily fitted by assuming the distribution function to be single and Normal Gaussian less frequently a bimodal function was required which was composed of two Normal distributions. Pulmonary clearance delay PCD values were derived from each model and also by a method of calculation directly from the raw data. The values obtained by all three methods agreed very well, and the three methods may be regarded as equivalent and interchangeable. By any of the three methods, all subjects except one showed on at least one occasion a PCD less than 10, but frequently the second of the paired determinations was somewhat higher up to 30. One subject, although considered normal on the basis of routine clinical testing, showed values which ranged from 30-100 delay. Author
- Anatomy and Physiology