> Bill Wolk wrote:
> >
> >The Buhlmann model is the best we have, but it's not perfect. It doesn't
> >take into account blood plasma transport of O2 -- among other things. In
> >that regard, it more closely models deco using 80/20 than 100% O2 which
> >means that I get out of the water with an extra margin of safety using
> >100% 02


> 
> Bill Wolk wrote:
> >
> >The Buhlmann model is the best we have, but it's not perfect. It doesn't
> >take into account blood plasma transport of O2 -- among other things. In
> >that regard, it more closely models deco using 80/20 than 100% O2 which
> >means that I get out of the water with an extra margin of safety using
> >100% 02


The Bühlmann- or any model which is calibrated to real dives , real
people, should be able to take this into account. If not by the pure
math, then by conservatism factors, allowed sursaturation or al.

Of course, the purely mathematical saturation model does not take into
account what you think of it should. 
It doesn't even take into account that you are a human being. It's
purely physics. 
It applies to any liquid/gas combination in a bowl, a pressure vessel,
what you like.

In this way , the model knows, of course, the fact of dissolved oxygen
in plasma. you could easyly calculate that. What it does not know, is
the fact that we diminish its partial pressure.
by consuming oxygen from this solution and by hemoglobin oxygenisation . 
It's weak point is, that is has to be calibrated to the fact, that
humans are not ideal bowls of olive oil and water, but have restrictions
like lungfiltering, circulation particularities , cavitational effects,
and others.

Any model needs to be calibrated to real life, that is in the
statistical mass it pretends to model, there we should find the
scenarios we do. Like switching to certain mixes at certain depths.
 
Switching to other gases at other depths, may even call for slightly
modified parameters.

Relying on beneficial effects of pure oxygen at 6m, seems to be somehow
crossing the border from decpmpression to hyperbaric treatment , if at
the same time these procedures are labeled "aggresive" decompression.
If this is something objectionable , I cannot say. The context in time
to bubble growth and its effects, which then are  cured by  oxygen, may
be short enough to leave no damage.
 Matthias
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