[PATCH] Show MOD, EAD, END and EADD

[Lutz Vieweg]

On 01/14/2013 09:58 PM, Jan Schubert wrote:
> In my understanding it does not matter for tissue saturation limits
> (defined by Haldane/Bühlmann/whatsever) if you dive with Nitrox or
> Heliox or Trimix

Actually, I have read quite the opposite thing - that e.g. the unloading
of He from the tissues requires a much more conservative profile / slower
ascending than unloading N2 saturation.

> Desaturation means things goes the other way round, meaning you have
> (mainly) to consider the pN2 in your tissues not in the gas breathing.

Well, if it is a valid simplification of the model to assume that
during the saturation of all the tissues in the body those tissues
are all exposed to the same pN2 the breathing gas consists of, then
it would be plausible to also assume all tissues are exposed to the same
pN2 from the breathing gas also while de-saturating.

But there is good reason not to simplify the model that way: Quite obviously,
the partial pressures of dissolved gases in the vicincy of some forming
bubble in some extremety is much different from the partial pressures in the lung.

Thus, to me it also sounds plausible to not assume there's a simple
"equivalent air depth" for EAN, because the pN2/pO2 in the vicincy of
all saturating and de-saturating tissues will not be just the same
as in the breathing gas.

That's why I don't really trust the "Equivalent Air Depth"-model computations.

Regards,

Lutz Vieweg