Thalmann Algorithm
Encyclopedia
The Thalmann Algorithm is a deterministic decompression model originally designed in 1980 to produce a decompression schedule for divers
using the US Navy Mk15 rebreather
.
It was developed by Capt. Edward D. Thalmann
, M.D., USN, who did research into decompression
theory at the Naval Medical Research Institute, Navy Experimental Diving Unit
, the State University of New York at Buffalo and Duke University
. The algorithm forms the basis for the current U.S. Navy mixed gas and standard air dive tables.
) would offer advantages. This algorithm was initially designated "MK15 (VVAL 18) RTA", a real-time algorithm for use with the Mk15 rebreather.
Linear Exponential (NMRI LE1 PDA) data set for calculation of decompression schedules. Phase two testing of the US Navy Diving Computer produced an acceptable algorithm with an expected maximum incidence of decompression sickness less than 3.5% assuming that occurrence followed the binomial distribution at the 95% confidence level.
Scuba diving
Scuba diving is a form of underwater diving in which a diver uses a scuba set to breathe underwater....
using the US Navy Mk15 rebreather
Rebreather
A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycled exhaled gas. This recycling reduces the volume of breathing gas used, making a rebreather lighter and more compact than an open-circuit breathing set for the same duration in environments where...
.
It was developed by Capt. Edward D. Thalmann
Edward D. Thalmann
Capt. Edward Deforest Thalmann, USN was an American hyperbaric medicine specialist who was principally responsible for developing the current United States Navy dive tables for mixed-gas diving, which are based on his eponymous Thalmann Algorithm...
, M.D., USN, who did research into decompression
Decompression
Decompression has several meanings:* Decompression , the release of pressure and the opposition of physical compression* Decompression sickness, a condition arising from the precipitation of dissolved gases into bubbles inside the body on depressurization* Decompression , a procedure used to treat...
theory at the Naval Medical Research Institute, Navy Experimental Diving Unit
United States Navy Experimental Diving Unit
The United States Navy Experimental Diving Unit is the primary source of diving and hyperbaric operational guidance for the US Navy...
, the State University of New York at Buffalo and Duke University
Duke University
Duke University is a private research university located in Durham, North Carolina, United States. Founded by Methodists and Quakers in the present day town of Trinity in 1838, the school moved to Durham in 1892. In 1924, tobacco industrialist James B...
. The algorithm forms the basis for the current U.S. Navy mixed gas and standard air dive tables.
History
The Mk15 rebreather supplies a constant partial pressure of oxygen of 0.7 bar (70,000 Pa) with nitrogen as the inert gas. Prior to 1980 it was operated using schedules from printed tables. It was determined that an algorithm suitable for programming into an underwater decompression monitor (an early dive computerDive computer
A dive computer or decompression meter is a device used by a scuba diver to measure the time and depth of a dive so that a safe ascent profile can be calculated and displayed so that the diver can avoid decompression sickness.- Purpose :...
) would offer advantages. This algorithm was initially designated "MK15 (VVAL 18) RTA", a real-time algorithm for use with the Mk15 rebreather.
Description
VVAL 18 is a deterministic model that utilizes the Naval Medical Research InstituteNational Naval Medical Center
The National Naval Medical Center in Bethesda, Maryland, USA — commonly known as the Bethesda Naval Hospital — was for decades the flagship of the United States Navy's system of medical centers. A federal institution, it conducted medical and dental research as well as providing health care for...
Linear Exponential (NMRI LE1 PDA) data set for calculation of decompression schedules. Phase two testing of the US Navy Diving Computer produced an acceptable algorithm with an expected maximum incidence of decompression sickness less than 3.5% assuming that occurrence followed the binomial distribution at the 95% confidence level.