A statistical model of the VA/Q distribution.
A "blocks model" is proposed to model the distribution of the ventilation-perfusion ratio (VA/Q distribution). This model is developed from statistical principles and enables the estimated VA/Q distribution to be interpreted in a straightforward and intuitive manner. Estimation of parameters of the blocks model uses a constrained weighted least-squares procedure. Although developed initially to estimate VA/Q distributions from data generated by the multiple inert gas elimination technique (P. D. Wagner, H. A. Saltzman, and J. B. West, J. Appl. Physiol. 36: 588-599, 1974), the blocks method is applicable to any problem in which the unknown distribution is related to the data through an ill-posed integral equation and is particularly suited for problems in which the data are scarce. The method is illustrated with several examples--hypothetical data representing a wide range of VA/Q distributions as well as some real data.
Lim
L L
LL
Department of Applied Statistics, University of Reading, Berkshire, United Kingdom.
D003198:Computer Simulation; D006801:Humans; D008954:Models, Biological; D015233:Models, Statistical; D009010:Monte Carlo Method; D005741:Noble Gases; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012126:Respiratory Dead Space / Q000502:physiology; D014692:Ventilation-Perfusion Ratio / Q000502:physiology*
D005741:Noble Gases