>...The basic problem is that we just don't understand as 
>much about "fizzyology" as we do about physiology.  The only prediction  
>we can make about DCI is that it will be a LONG time before we understand 
>it well enough to make any predicitons about DCI.  
>
>I think a more fruitful approach is to go out in the real world and see
>what people are actually doing, and what sorts of things get people bent
>less often than other sorts of things.  If you look at commercial diving
>fishermen in th tropical Pacific, you'll see that they are doing profiles
>that will keep you awake at night in a cold sweat...

Rich, you've got my vote on that one! (at least in my more bleary-eyed 
moments!) In pathology, we'll sometimes refer to collegues as being 
either "lumpers" or "splitters". Those that prefer to look at the 
overall, global disease process (they try to lump variants of tumors 
under broader catagories) and those that wish to take things apart, piece 
by piece like an old watch (they like to find sub-catagories to 
sub-catagories to sub-catagories...). (PS:med students that have to 
memorize lists hate these people for obvious reasons)

Don't misunderstand, there's a place for both, but the body's response 
and the changes in the various gas physics (fizz'iks?) seem so 
overwhelming at times (at least for me) that it sure is tempting to take 
the "practical" low-tech approach and treat the diver as a simple "black 
box"... make specified changes and then just see "what works" instead of 
trying to figure which exact steps are responsible for that result. Of 
course, if you don't understand the steps involved you've little hope of 
optimizing those results in the future.

In a previous correspondence to the list, I mentioned that the Navy's 
"NATOPS" (Naval Aviation Training & Operation Standards) were "written in 
blood". Over the years, data collected on what *didn't* work was used to 
make changes in aircraft design and safety procedures. In a sense, the 
dive tables were written the same way...in blood. 

Imagine back at some prehistoric dive site, Og and Charley made an 
ascent. Charley raced to the surface and turned into an Alka-Seltzer on 
the way. Og saw his bud Charley's demise and made a note not to do that! 
(chiseled on a stone slab as the first Mark 1 dive table). Appears like 
the Pacific divers have done the same.

In my *brief* studies on DCS, I'm beginning to wonder if predicting (and 
therefore avoiding) it is like predicting the weather. There are so many 
individual diver and environmental variables to track, that interact with 
each other, that the *best* you'll ever do is a decent first order 
approximation. With all the high tech equipment and our science of 
meteorology, we still end up just opening a window and looking outside ;-)

We dive much the same way. Anacdotally we see what works (then we go take 
our wetsuits off and put on white lab coats to "rationalize" why what we 
saw with our own eyes really happened!)

We see that aerobically conditioned athletes/aviators/divers do better in 
most every stressful activity you name, yet we all get on this list and 
pick it apart trying to devine the exact step in the membrane transport 
mechanism that "proves" that the field evidence was real. As Freud once 
said, "Sometimes a cigar is just a cigar!" If something works I'll take 
it on face value and use it...then worry about *why* later.

Hey, I'm a simple guy. When I go below the surface and draw a breath 
through my regulator I try not to clutter my head with thoughts like "I 
wonder what my cytochrome B levels are so I can handle terminal oxygen 
transport?" There more like "Where the @#$% is my octo if this sucker 
doesn't work?!!!"

So yes Rich, there is a place for your KISS approach to the study of dive 
"fizzyology" At least for me..it's the only one I can understand!
 
;-)
Take care.

Robb Wolov

Navigate by Author: [Previous] [Next] [Author Search Index]
Navigate by Subject: [Previous] [Next] [Subject Search Index]

[Send Reply] [Send Message with New Topic]

[Search Selection] [Mailing List Home] [Home]