The last body part to reach full saturation

[sydney-diver]

Uwatec is a bit more complex to code due to changing time constants(work) and M-values change as a function of history, but it's not difficult.

I didn't think it was published? If it is do you have links to a paper?

 

[NiclasG]

Uwatec has not published the algorithm, but I worked there many years ago. The above sentences is what Uwatec has told in public.

 

[Dr Deco]

The "gas phase" I refer to is an actual gas bubble. It is at equilibrium with tissue except for a small addition by surface tension.

The slow decompressions from saturation are probably off gassing bubbles and not a true 600-minute tissue compartment.

 

[huwporter]

The "gas phase" I refer to is an actual gas bubble. It is at equilibrium with tissue except for a small addition by surface tension.

The slow decompressions from saturation are probably off gassing bubbles and not a true 600-minute tissue compartment.

Thanks very much for clarifying! I guess the critical question for saturation decompression then becomes the point at which these off-gassing bubbles cease to be symptomless and start causing symptoms.

Do you think that the series tissue concept (as per DCIEM) has any role in creating "virtual slow compartments" as well?

(Sloe compartments sound good though - is that what you are saturating when testing the Martini law? )

Cheers,
Huw

 

[Andy077]

I'd say its the part of the body with the least gas solubility, most distal to the heart, so, cartilage in the toes?

 

[kaerius]

One thing that strikes me about this thread and the talk of bones... when you're talking about the solid part of bones... I'm not sure they would absorb any gas at all(the marrow is another matter).

I mean, is there a law for solubility of gas in solids? We absorb gas because we're mostly made of water, and gas dissolves into liquid.

 

[DocVikingo]

... when you're talking about the solid part of bones... I'm not sure they would absorb any gas at all(the marrow is another matter).

Hi Kaerius,

Bone is living tissue and is perfused, some of it very well perfused. Blood supply varies depending upon type of bone and location within the bone. As you indicate, supply is especially rich in areas containing red bone marrow. On balance, bone probably receives 10-20% of cardiac output of blood.

Obviously bone is harder than say soft tissue, but it is not a near absolute "solid" such as diamond. Even very hard bone contains small spaces and is composed of molecules that have some degree of movement. Also, bone contains water and other liquids.

As such, bone proper does absorb additional gases during SCUBA at depth, although extremely slowly.

Regards,

DocVikingo

 

[DCBC]

Does anyone know what the last body part to reach full saturation?

I suspect that this would be the bones, as the joints & bones have the highest half-time (Edmonds, Lowry and Pennefather, 1991).

 

[Dr Deco]

Hello Kaerius:

If, academically, you are talking about the last tissue to absorbed gas, that would be bones and teeth. These do not play a role in joint-pain DCS; that is probably from connective tissue. Some tissues are very rapid, such as muscle or fat, but these do not play a role in joint-pain DCS. [These latter two are involved in other aspects of DCS, however.]

All tissues have numerous components. When I work at Ocean Systems, my chief, Dr Schreiner, would say that table “compartments” represent the different portions of tissues and even portions of cells themselves. These latter are composed of water, protein, and fats, for example.

Dr Deco :doctor: