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   Earnest and List Folks,



    Wanted to also add to my earlier comments about RGBM and/or VPM the
  following pertaining to operational (REAL) diving:

    7)  RGBM tables (NAUI Tec nitrox, heliox, trimix Tables), meters (Suunto,
        Plexus, HydroSpace, "new" ones), and commercial software (ABYSS
        and some Tim O'Leary and I will release) ABOUND (the past 3 - 4
        years), and collectively have logged many 10,000s of technical
        and recreational dives with only a 2 reported cases of DCS  So,
        RGBM DCS incidence rate is virtually zero, especially on the
        technical envelope where it matters most as a model test.
        NOT SO to my best knowledge for the VPM as far as validation,
        testing and use, though the crude dynamics are likely similar.

     8) RGBM successes span technical deco, altitude, and mixed gas diving,
        which are the real test of any model.  Recreational diving
        is a rather simple limit point for the RGBM -- albeit, an important
        one just considering diver numbers, but one that tests virtually
        nobody's deco or staging mode, except for repetitive and reverse
        profile diving maybe.

     9) the RGBM bootstraps parameters to diving data (DCS rate) using maximum
        likelihood, the VPM does NOT.

    10) NAUI RGBM Tables for the recreational diver on air, EAN32, EAN36,
        from sea level to 10,000 ft elevations have been tested over the
        past few years, and are being released as simple, no-calc, no
        group, no-bull tables with simple rules for repets, flying-after-
        diving, SIs, etc, etc.  Check with NAUI Hdqts, or NAUI Tec Ops

    11) NAUI RGBM Tec Tables have been forged over the past 8 yrs from
        operations of the LANL Countermeasures Team, NAUI Tec Instructor
        Training Courses, reported WKPP extreme diving profiles, and 100s of
        field reports graciously sent to me (us) by the technical community.
        (see TDID for more here).

    12) Deep stops are natural to both the RGBM and VPM, but RGBM deep
        stops have NAUI Tec tests and stamps of approval down to 300 fsw
        on trimix -- ditto for the LANL Team.

    13) RGBM modified Haldane meter algorithms are bubble folded schemes
        that exist in some deco meters, and have been used very
        successfully for repetitive, reverse profile, and multiday
       apps, but NOT so with the VPM.

   Thanks -- hope this is useful.

  BW


>Date: Mon, 18 Feb 2002 16:18:59 -0700
>To: "Ernest S Campbell, MD" <scubadoc@gu*.co*>
>From: "Bruce R. Wienke" <brw@la*.go*>
>Subject: RGBM vs VPM Deco Models
>Cc: Nauitec@ao*.co*, techdiver@aquanaut.com, deco@de*.or*
>Bcc:
>X-Attachments:
>
>
>   Earnest,
>
>     Just read your Newsletter Mailbox answer to question about
>  RGBM vs VPM.  There is quite a bit more all should know (major
>  differences) -- actually the RGBM abandons the gel physics of the VPM
>  as NOT applicable in toto to blood and tissue.  Consider comments:
>
>    1)  RGBM does NOT use (VPM) gel bubbles as model for tissue and blood
>        bubbles;
>
>    2)  RGBM deduces bubble persistence time scales (how long they hang
>        around) FROM seed skin structures (lipid or aqueous), not a-priori
>        weeks as ASSUMED in the VPM;
>
>    3)  RGBM bubbles are permeable to gas transfer DEPENDING on their
>        skin structure always, NOT at some cutoff pressure as in the
>        VPM gel studies;
>
>    4)  biophysical equations-of-state (EOS) for lipid and aqueous
>        substances relate seed pressure, temperature, diffusivities to
>        gas transfer, and skin structure in the RGBM, and, as such,
>        are OUTSIDE the VPM;
>
>    5)  the RGBM transfers gas across the bubble interfaces, the VPM
>        does NOT;
>
>    6)  See new book "Technical Diving In Depth" by Wienke
>        (Best) for more on same subject.
>
>      Thanks.
>
>      With all due respects to my friend and decreased colleague, David Yount,
>  I must go on record as NOT accepting that VPM gel dynamics apply routinely
>  to the body, nor the properties he studied.  Such VPM type bubble seeds
>  have NEVER been found in the body -- nor outside of "gel-like" media.
>  RGBM (EOS) bubbles do recover VPM bubbles in limiting circumstance of
>  material strength and pressure, but that is not important to the RGBM.
>  Naturally occuring bubble "seeds" in the atmosphere and oceans are
>  NOT akin to VPM gel bubbles -- NOR should they be.  The body, oceans,
>  and atmosphere are NOT gel.
>
>
>
>   BW
>
>
>


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