Enforced Smoothing Techniques for Recovering VA/Q Distributions from Inert Gas Data

Enforced smoothing techniques for computing V_A/Q distributions from inert gas retentions were evaluated by recovering distributions from artificial data. The value of the smoothness parameter z was varied with smoothness constraints that minimized the area either under the square of the distribution or under the square of the second derivative of the distribution. The accuracy of the recovered distributions were quantified by the RMS difference between the original and the recovered distributions. Values of z outside of a certain range (typically, 0.01