• New DCI Modelling

       " Researchers have created a new model for predicting decompression sickness after deep-sea dives that not only estimates the risk, but how severe the symptoms are likely to be.

        The US Navy Diving Manual may incorporate the model into its next update, as will commercial products intended to help recreational divers plan their ascents to avoid "the bends."

        The results appear online on March 15, 2017, in the journal PLOS ONE.

      "The current guidelines only give you a probability as to whether or not decompression sickness is likely to happen after a given dive," said Laurens Howle, professor of mechanical engineering and materials science at Duke, who has been working on these models with the Navy for a decade. "This is the first time we've been able to also address the likely severity of the potential sickness, helping divers determine acceptable risk."

        All risks have two components -- the likelihood of something bad happening and just how bad that something is likely to be. Having a model that accurately provides both aspects will allow divers to better plan safe depths and ascents to help their bodies adjust -- preventing painful and potentially fatal results."

    Link to new DCI modelling



    Scroll to the bottom of the page to download the document as well


    The link to the journal PLOS ONE article is below.


    1 person likes this

      Report Article

    User Feedback


    i don't understand this article. You can't predict where a bubble will end up and how painful it will be. Each dive and diver are different. Hence a neurological exam.

    1 person likes this

    Share this comment

    Link to comment
    Share on other sites

    Hi Derek - fascinating  (And NO, I did not follow the maths!).


    Basically used records of over 3,000 actual dives and applied a three state model to predict no DCI, mild DCI (Pain only) and Serious DCI (Cardio/neurological DCI)


    They used the 2008 (Rev 6) USN tables 'no decompression limit' to compare the US Navy's 'standard' of accepting up to a 2% risk of mild DCI and 0.1 % risk of serious DCI (I'm not sure many commercial diving people will accept a hit rate of 'one serious DCI per 1000 dives as normal)


    They concluded that the USN 2008 'no decompression limits' was conservative for mild DCI - ie you could - theoretically!!! - dive longer for the before you reach the 2% risk of mild DCS


    BUT they also noted that you had to 'vastly reduce' bottom times to keep within the 0.1 % risk of serious DCS


    To meet the 0.1% risk of serious DCI, the table they quoted was the French Navy NM90 table.


    Which kind of supports a lot of people's gut feeling that the old USN air tables are a tadge risky when used straight out of the box  - even the US Navy concluded they produced an unacceptably high rate of DCS in the deep air range - That's why they upgraded from Rev 6 to Rev 7 last yea (And why they upped from Rev 5 to Rev 6 in 2008).


    I believe - but am open to being corrected! - that the French Navy tables are based on a Haldanian model (derived from extrapolating data from actual dives) as opposed to Algorythms (bubble modelling maths) which kind of pushes one to think that science is good, but actual experience is better.


    It would be interesting if they re-ran the modelling using the NDL limits from USN Rev 7 to see if the new version is any safer.


    Thanks for posting the link!







    2 people like this

    Share this comment

    Link to comment
    Share on other sites

    Create an account or sign in to comment

    You need to be a member in order to leave a comment

    Create an account

    Sign up for a new account in our community. It's easy!

    Register a new account

    Sign in

    Already have an account? Sign in here.

    Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Pro Memoriam

    • John Webb
      John Webb
    • Joshua Rodriguez Marquez
      Joshua Rodriguez Marquez
    • Jose Joaquin Lopez Cruz
      Jose Joaquin Lopez Cruz
    • Rajesh Dabbas
      Rajesh Dabbas
    • Chris Hollifield
      Chris Hollifield
    • Thiago Matheus Coutinho
      Thiago Matheus Coutinho
    • Marko Knaps
      Marko Knaps
    • Brian Ernest
      Brian Ernest
    • Chris Wilson
      Chris Wilson
    • Christopher Whittaker
      Christopher Whittaker
    • Gerald Chia
      Gerald Chia
    • Leticia Castiglione
      Leticia Castiglione
    • Steve Acton
      Steve Acton
    • NK Sharma
      NK Sharma
    • Chandra
    • Tony Eke
      Tony Eke
    • Cristian Zarafu
      Cristian Zarafu
    • Louis Ricciarelli
      Louis Ricciarelli
    • Dave Courcoux
      Dave Courcoux
    • Ottavio Baumgartner
      Ottavio Baumgartner
    • Peter Small
      Peter Small
    • Earl Guidry
      Earl Guidry
    • Pierre Rossouw
      Pierre Rossouw
    • Kenny Kruckenberg
      Kenny Kruckenberg
    • Godwin Udoh
      Godwin Udoh
    • Miura Yusuke
      Miura Yusuke
    • Joseph Gould
      Joseph Gould
    • Brian Pilkington
      Brian Pilkington
    • Jean Christophe Casagrande
      Jean Christophe Casagrande
    • Marc Begnaud
      Marc Begnaud
    • Christopher Logan
      Christopher Logan
    • Russ Robinson
      Russ Robinson
    • Daniel Heres Ã�lvarez
      Daniel Heres �lvarez
    • Norlan Vásquez Rodríguez
      Norlan Vásquez Rodríguez
    • Radoslav Stoyanov
      Radoslav Stoyanov
    • Kevin George
      Kevin George
    • Matt Smock
      Matt Smock
    • Julio Dacosta Gallo
      Julio Dacosta Gallo
    • David Mato Garrido
      David Mato Garrido
    • David Scheinost
      David Scheinost
    • Edward Hayman
      Edward Hayman
    • S.S. Chauhan
      S.S. Chauhan
    • Richard Wilkinson-Lowe
      Richard Wilkinson-Lowe
    • Travis Muller
      Travis Muller
    • Rafael Santos Aragão
      Rafael Santos Aragão
    • Dhirendra Kadiyan
      Dhirendra Kadiyan
    • Javier Diaz Macias
      Javier Diaz Macias
    • David Mitchell
      David Mitchell
    • Ajesh Gaur
      Ajesh Gaur
    • Carlos Isaias Melipillan Coliboro
      Carlos Isaias Melipillan Coliboro
    • Stephen O'Malley
      Stephen O'Malley
    • Rob Holbrook
      Rob Holbrook
    • Pervinder Kadiyan
      Pervinder Kadiyan
    • Olivier Rouxhet
      Olivier Rouxhet
    • Jonathon Parker
      Jonathon Parker
    • Luke Rupping
      Luke Rupping
    • Sondre Birkeland
      Sondre Birkeland
    • Jarrod Hampton
      Jarrod Hampton
    • Fernando Robles Aller
      Fernando Robles Aller
    • Jamie York
      Jamie York
    • Chandon McGrath
      Chandon McGrath
    • David Sparks
      David Sparks
    • JS Padda
      JS Padda
    • Luke Seabrook
      Luke Seabrook
    • Paul De Waal
      Paul De Waal
    • Israel Franco Marino
      Israel Franco Marino
    • Mohammed Borhan Jamal
      Mohammed Borhan Jamal
  • Latest Incident Follow Up Posts

    •   Tony, Please keep us updated of any developments. I know it has to have been a hell of a struggle for you.
    • Thanks very much for posting this update Mark. We are very confident of safety improvement within this industry as a result of the inquest, and if not then we will continue to campaign. I am sure some employers do not appreciate the value of a life let alone an individuals right to a safe workplace.
    • Taken from this post:      Hello Hal, below a translation from the newspaper El Siglo:   Elmer Quintero Cedeño

      Sources said that divers were trapped and sucked by the current


      Two divers died after being sucked by a sewer at a time when they were cleaning a canal at the Gualaca Hydroelectric Power Plant of Celsia Centroamérica, S.A., in Gualaca, Chiriquí.

      The facts were recorded at approximately 12:40 pm yesterday afternoon.

      Citizens Roderick Araúz, 35, and Jose Garcia, 43, were hired by the hydroelectric company to carry out work as divers and clean the canal that reorients the waters of the River Estí and, while carrying out these tasks, were dragged by the Current through a sewer that I push them to another channel.

      Ambulances of the firemen of Gualaca and other security institutions were transferred to the place, and the staff performed cardiopulmonary resuscitation (CPR) maneuvers, but the effort was in vain.

      In the same way police units were presented, of the Sinaproc, Firemen, DIJ, Criminalistics and the Municipality of Gualaca.

      The Personería carried out the lifting of the corpses of these two people.

      Roderick Araúz was captain of the Volunteer Fire Department at Gualaca Station and worked as a firefighter at Enrique Malek Airport in David.

      According to a statement from the company Celsia Centroamérica, the two divers were hired by the contractor Interpa Holding Corporation, S.A, which was routinely called to carry out works on the canals.

      It was indicated that, as soon as the accident was known, the emergency plan was activated and representatives of Celsia Central America contacted the corresponding authorities to provide immediate attention.

      "At the moment the company is providing the necessary support both to the relatives of the deceased and to the authorities, in order to clarify the facts and determine the causes of this unfortunate accident," the company said in a statement. End of translation from El Siglo Newspaper.   Facts that I obtained: The divers were Scuba Divers, the "Contractor" company was owned by one of the divers. They were using scuba at the moment of the incident. One of the reasons this things happen here is because there is no law for dive operations. A group of professionals presented a law that will be discussed by senators in January 2017 (we been trying for years but politicians always find the way to block it). Will keep you updated on any advance regarding the dive law. Gabriel