UTD Decompression profile study results published

[Kevrumbo]

If the end result is the same then what's it matter?

As the practical solution is with any Bubble Model algorithm of which UTD's RD had the history of the longest & deepest deepstops, you're gonna have to extend & pad your O2 deco stops to effectively decompress the surfacing slow tissue tensions if you choose to use RD.

 

[boulderjohn]

I agree it shall be only used as backup, apparently it is used as the way to go by a few.

It is used as the only way to dive by UTD. I don't know anyone else who does that.

Technical instruction for most agencies still teaches divers to plan their dive using desktop software and then make contingency plans using that same software for dives that were reasonably close to the planned dive in case you strayed from that plan somewhat. You would then perform the dive using a bottom timer or a computer in gauge mode. If you did this often enough, you could pretty much predict what those contingency plans would look like, meaning that if you strayed from the plan a bit, you could make a reasonable approximation of a new plan without the software. My understanding is that this is essentially how ratio deco started, as a way to make those contingency plans on the fly. It made sense to do it that way.

Then AG decided that his version of RD was superior to the deco software programs, so that made the deco software programs unnecessary. You just followed his version of RD.

I experienced both of the above, first with the RD only and then with the deco software plus backups system. When I left UTD, that is what everyone I dived with was doing. Everyone on the boats I was on had their written plans, often printed off a computer and then covered with tape on a slate. Then I did some diving in which some people were using the three written plans PLUS having a computer with the same algorithm (VPM) as a backup. What was interesting is that when I dived with them this way, they would follow the written plan but wait on each stop for the computer "backup" to match them. That led me to wonder whether they were following the written plan with the computer as a backup, or whether they were following the computer with the written plans as backups.

When I dive today, I don't see anyone using a written plan as their primary plan. I don't claim to have surveyed everyone on the dive boats I have used, but I look around and observe carefully every time I dive. What I see is people either using computers to guide their dives with written plans as a backup (I assume they have backup somewhere--I just see them using the computers), or people using two computers.

I do not personally see people using Ratio Deco any more. I assume they exist, just not on the boats where I dive. I see almost everyone has gotten to the point that they either use a computer as their primary with a written backup or they use two computers. A Ratio Deco user would be someone who is still not willing to use a computer, so they will either use Ratio Deco as a backup or their only plan.

 

[Diver0001]

If the end result is the same then what's it matter?

It's not. That's the point.

George Irvine, one of the early "fathers" of DIR, used to refer to WKPP divers getting bent somewhat jokingly (this is going back some 20 years now). It is, of course, no laughing matter but the fact that a minor bend seemed (or was presented at the time) as some kind of coming of age within the DIR (or at least the WKPP) community seems odd now with the advent of good computers and the deeper understanding we have of deco theory.

The fact that some tek divers still use ratio deco at all seems as out of place in a modern context as following the "120 rule" that I learned in 1984. Some things just NEED to change as we learn to understand them.

However, as I said above there is a "hardend belief" (a paradigm) within the DIR community that makes it hard for some of the "hard core", especially the elite hard core who have built careers pushing this paradigm, to address issues openly and logically in the context of new technology and new insights. Don't forget that WKPP and DIR in general were early and fanatical adopters of Bruce Wienke's thoughts on deco and they have not let that go despite the overwhelming evidence that Buhlmann gets the job done better.

Hence the blanket statements in the video the OP posted more or less condemning Buhlmann and more or less "prescribing" the outcome of the study.

That's not science. That's religion. ... faith before logic ...

As it is, ratio deco is still part of the training and will probably remain so even though it is demonstrably inefficient and somewhat more risky than learning how to use a modern technical computer. I predict that it will be some time before DIR divers start to question this paradigm from the inside.

And THAT is the current state of affairs surrounding ratio deco.

R..

 

[Kevrumbo]

If the end result is the same then what's it matter?

What matters. . . As the practical solution is with any Bubble Model algorithm of which UTD's RD had the history of the longest & deepest deepstops, you're gonna have to extend & pad your O2 deco stops to effectively decompress the surfacing slow tissue tensions if you choose to use RD.

. . .Getting off the bottom (that is, skipping the deep stops) can reduce tissue loading in intermediate and slow tissues. No matter what is done at depth, prolonging shallow stop time is effective at reducing VGE in individuals predisposed to develop them. Other strategies might work, but I am most impressed by those based on credible evidence. I call prolonged shallow stops really cheap insurance.

Neal Pollock Ph.D

https://www.ccrexplorers.com/community/threads/diving-tooh-carefully.18348/page-18#post-178445

Objectively, I think just in general, the above advice is a practical option for any deco algorithm in use, and especially a solution for anyone still choosing to use RD.

 

[lowflyer]

My career dealt with inflammatory disorders, so I'm curious what these "inflammatory" or "immune" markers were in this study. Anyone know?

 

[tursiops]

My career dealt with inflammatory disorders, so I'm curious what these "inflammatory" or "immune" markers were in this study. Anyone know?

I guess reading the actual paper would provide some answers.

 

[Remy B.]

I car analogies: you do realise that airbags exist primarily because people wouldn't wear seatbelts, yes?

So far I know it was made to decelerate your body far more effectively than the seat belt which is barrier #1, Airbags #2, ABS #3, common sense priceless, so if you don't make good use of the last one the others will not safe your arsh

 

[victorzamora]

My career dealt with inflammatory disorders, so I'm curious what these "inflammatory" or "immune" markers were in this study. Anyone know?

Circulating chemokines CCL2 and CCL5, I believe.

 

[Kevrumbo]

My career dealt with inflammatory disorders, so I'm curious what these "inflammatory" or "immune" markers were in this study. Anyone know?

Circulating chemokines CCL2 and CCL5, I believe.

When my clinical labs were drawn in 2008 for DCS type 1 with possible DVT/PE, the panel D-dimers and creatine phosphokinase (CPK) levels were elevated. . .

 

[Remy B.]

If the end result is the same then what's it matter?

It works for you and for AG from UTD as well that VPM well work, but since every body have their differences, and scientific studies tells us that there are markers showing that it can be done better, I guess it is reasonable to follow what works for each one or follow the trend of the scientific indications.