Statistically Based Decompression Tables 5: Haldane-Vann Models for Air Diving.

Abstract : This report continues the analysis of air decompression diving by probabilistic models evaluated using the statistical tool of maximum likelihood. Models based on the traditional deterministic calculations of Haldane have been placed in a probabilistic formalism by Vann. The ability of these models to fit data examined in the first and fourth reports in the present series were explored here. The computationally simpler Haldane-Vann (H-V) models achieved comparable success fitting relatively homogeneous data to the risk models used in the earlier reports in this series. However, H-V models were unable to deal successfully with larger and more diverse collections of data. It appears that the Vann definition of decompression 'dose' intrinsically cannot lead to simultaneously successful predictions of both short and long air dives. Keywords: Graphs; Formula mathematics; Decompression sickness; Mathematical models; Inert gas kinetics; Risk assessment. (kt)