Trimix Update - from Uemis.com

[iztok]

Keep in mind folks, this is the UEMIS forum. It is implementing a ZHL 8+ algorithm. If we are headed off on a discussion about the algorithms in the Galileo and soon to be implemented in the Galileo could you please take it over to the general dive computers or Scubapro forum? Thanks!

We know that Zurich now uses ZHL 8+, will this still be the case with Trimix?

 

[DiverLaura]

i believe so, but i will get confirmation.

a bit more regarding the ZHL 8+ for those who have not already read it elsewhere...

it takes more computing power as i understand it, so not being used as a function of the processor limitations like in the 'old days'

ZHL8+ is adaptive, its compartments adapt to workload, skin cooling and microbubbles in real time during the dive

ZHL8+ has infinite compartments due to the fact that the 8 compartments continuously change tissue half times and M-values according to workload, skin cooling and microbubbles during diving and surface interval

 

[iztok]

ZHL8+ has infinite compartments due to the fact that the 8 compartments continuously change tissue half times and M-values according to workload, skin cooling and microbubbles during diving and surface interval

While we are at the compartments topic. Can we remove the names of the compartments based on human tissues? It is simply wrong and bad science. There is no real correspondence of compartments to actual human tissues. However in Zuerich tissues are named (skin, muscles, fat, joints ...). It gives someone false impression that theoretical tissues match the named tissues.

 

[ianr33]

ZHL8+ is adaptive, its compartments adapt to workload, skin cooling and microbubbles in real time during the dive

How do you know the temperature of the divers skin?

 

[iztok]

How do you know the temperature of the divers skin?

Assumes from surrounding water temp w/o account for real exposure protection diver is wearing.

I.e. One diving in 50F might be wearing 7mm farmer john or dry suit

 

[DiverLaura]

While we are at the compartments topic. Can we remove the names of the compartments based on human tissues? It is simply wrong and bad science. There is no real correspondence of compartments to actual human tissues. However in Zuerich tissues are named (skin, muscles, fat, joints ...). It gives someone false impression that theoretical tissues match the named tissues.

I will forward this request on to Ernst, but as I understand it, the 'names' give recreational divers an idea of what is ongoing. are you saying that you do not agree that blood is a fast tissue and fat/cartilage is a slow tissue, hypothetically speaking, in this application?

 

[iztok]

I will forward this request on to Ernst, but as I understand it, the 'names' give recreational divers an idea of what is ongoing. are you saying that you do not agree that blood is a fast tissue and fat/cartilage is a slow tissue, hypothetically speaking, in this application?

Unless Ernst figured out proper model for CNS, fat, joints etc... it is simply irresponsible to name the compartments after body tissues.

I think it would be more appropriate to display half time number instead of naming the tissues that are hypothetical.

 

[iztok]

as I understand it, the 'names' give recreational divers an idea of what is ongoing

Are recreational divers under any agency actually told that model represents actual tissues vs. hypothetical? My instructors (PADI and SSI) specifically said these do not correspond to any real human tissue.

 

[iztok]

BTW: I complain because I care. I love the computer and it has awesome potential to be the market leader.

 

[ianr33]

Assumes from surrounding water temp w/o account for real exposure protection diver is wearing.

I.e. One diving in 50F might be wearing 7mm farmer john or dry suit

Exactly my point.

50F might leave a diver in a 3mm wetsuit hypothermic, whereas with a drysuit, good underwear and maybe even an electric heater, a diver could be toasty warm.
The computer has no way of knowing what a divers skin temperature actually is. Even if it did, what is the relationship between skin temperature and DCS risk? How is that modeled? My guess is they just take a WAG at it,triple the conservatism after discussion with lawyers then market it as a breakthrough in diver safety.

But then I'm a cynic.