An anatomically approximate prosthetic heart valve includes dissimilar flexible leaflets, dissimilar commissures andor a non-circular flow orifice. A transformation function is then obtained based on the number of states to advance the PN code sequence. of from 5 to 50 mm2sec, a viscosity index of at least 60, and a water content of at most 300 ppm. The parameters used comprise the maximum cell transfer delay, the peak-to-peak Cell Delay Variation, the Available Cell Rate, the Maximum Cell Rate and the Cell Loss Ratio.