Fig. 3From: Generalized estimation of the ventilatory distribution from the multiple-breath nitrogen washoutDistributions recovery flow chart. Nonnegative least squares are used either unconstrained or constrained (imposed values for tidal volume, end-expiratory lung volume and series dead space) considering a chosen weighting matrix, a Tikhonov gain and different number of breath cycles. Black dots indicate that flow chart continuation coincides with the correspondent at the same levelBack to article page