bit of light reading
bit of light reading
I found this an interesting read, especially the use of inflammatory markers as an early warner for DCS. It does give an interesting idea of physiological stress caused by the gas loading, even with no clinical symptoms of DCS. This could be a good explanation for "unexpected" bends after multiple dives or other physiological stressor, even if within conservative limits.
only skim read so far but a 30/85 GF profile compared against a Ratio profile? Apart from the elongated stop at switch depth on the Ratio aren't these 2 very similar in terms of deep stops?
I know a bit about this study. It is included in an article I just co-authored with Simon Mitchell about the issue of deep stops. It will be published in the PADI Tech forum soon. The reference in the article to this study is brief, but there is a lot more that could have been said.
The study was initiated by (and I believe financed by) UTD. UTD owner Andrew Georgitsis published a video before it started raving about how the study was going to show the superiority of the UTD ratio deco program to a common Bühlmann algorithm. (This is, of course, not the way you are supposed to approach an objective scientific study.) When the intention to do the study was first announced, several people criticised it, arguing that it was set up to make the UTD system look good. They were especially critical of the GF high of 85, which made for a different length of total deco, with the RD group getting more time to decompress in the shallow stops. This should have given the RD group an advantage.
Since then, UTD changed to a new version of Ratio Deco, Ratio Deco 2.0. I am not totally familiar with it, but I believe it makes the first stop at 2/3 of average depth rather than 3/4, and I believe it also drops the S-curve from the middle ascent range.
Last edited by JohnAdsit; 12-04-2019 at 06:37 PM.
There is some interesting and related stuff on the SB Re-Evaluating my GF thread which demonstrates that holding the gas switch stop can lessen ISS but think it was mainly applicable to air/nitrox dives not trimix.
Still not sure a GF low of 30 was representative of a suitably dissimilar profile, but it does highlight the issue with deep stops.
The ultimate goal is to try to find the best possible ascent profile, which of course includes the most effective depth for the first stop. Finding that depth requires us to maintain an open mind and accept that because our understanding has not yet reached perfection, we must constantly seek and evaluate new information as it becomes available.
So how many ratio deco (not the UTD fucked us versions) compare with the profile investigated.
Do either GUE or UTD do air to 50m.
Should have done an ‘88 to this profile test.
Rebreathers are like women; they pretend to love you, whilst taking all your money and trying to kill you.