Not to be confused with Decompression practice or Decompression sickness.
Scuba diver decompressing at a planned stop during ascent from a dive
Decompression theory is the study and modelling of the transfer of the inert gas component of breathing gases from the gas in the lungs to the tissues and back during exposure to variations in ambient pressure. In the case of underwater diving and compressed air work, this mostly involves ambient pressures greater than the local surface pressure,[1] but astronauts, high altitude mountaineers, and travellers in aircraft which are not pressurised to sea level pressure,[2][3] are generally exposed to ambient pressures less than standard sea level atmospheric pressure. In all cases, the symptoms caused by decompression occur during or within a relatively short period of hours, or occasionally days, after a significant pressure reduction.[4]
The term "decompression" derives from the reduction in ambient pressure experienced by the organism and refers to both the reduction in pressure and the process of allowing dissolved inert gases to be eliminated from the tissues during and after this reduction in pressure. The uptake of gas by the tissues is in the dissolved state, and elimination also requires the gas to be dissolved, however a sufficient reduction in ambient pressure may cause bubble formation in the tissues, which can lead to tissue damage and the symptoms known as decompression sickness, and also delays the elimination of the gas.[1]
Decompression modeling attempts to explain and predict the mechanism of gas elimination and bubble formation within the organism during and after changes in ambient pressure,[5] and provides mathematical models which attempt to predict acceptably low risk and reasonably practicable procedures for decompression in the field.[6] Both deterministic and probabilistic models have been used, and are still in use.
Efficient decompression requires the diver to ascend fast enough to establish as high a decompression gradient, in as many tissues, as safely possible, without provoking the development of symptomatic bubbles. This is facilitated by the highest acceptably safe oxygen partial pressure in the breathing gas, and avoiding gas changes that could cause counterdiffusion bubble formation or growth. The development of schedules that are both safe and efficient has been complicated by the large number of variables and uncertainties, including personal variation in response under varying environmental conditions and workload.
^ abCite error: The named reference USNDM R6 3-9.3 was invoked but never defined (see the help page).
^Cite error: The named reference Van Liew and Conkin 2007 was invoked but never defined (see the help page).
^Cite error: The named reference FAA was invoked but never defined (see the help page).
^Cite error: The named reference USNDM R6 20-3.1 was invoked but never defined (see the help page).
^Cite error: The named reference Gorman was invoked but never defined (see the help page).
^Cite error: The named reference Wienke was invoked but never defined (see the help page).
and 26 Related for: Decompression theory information
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ambient pressures. Decompression obligation for a given dive profile must be calculated and monitored to ensure that the risk of decompression sickness is controlled...
bubbles inside the body tissues during decompression. DCS most commonly occurs during or soon after a decompression ascent from underwater diving, but can...
or fail to pressurize at all. Such decompression may be classed as explosive, rapid, or slow: Explosive decompression (ED) is violent and too fast for air...
tissues Decompression (diving) – Pressure reduction and its effects during ascent from depth Decompressiontheory – Theoretical modelling of decompression physiology...
University of Adelaide. His "thermodynamic decompression model" was one of the first models in which decompression is controlled by the volume of gas bubbles...
remaining decompression as surface decompression either after an ambient pressure ascent or after transfer under pressure from a dry bell. (decompression chambers)...
area. The current also did its work." The latest reference to the decompressiontheory of the missing bodies was made by Lieutenant General Valeri Kamenski...
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A dive computer, personal decompression computer or decompression meter is a device used by an underwater diver to measure the elapsed time and depth...
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The thermodynamic model was one of the first decompression models in which decompression is controlled by the volume of gas bubbles coming out of solution...
was the site of several serious incidents, most notably an explosive decompression in 1983 that killed four divers and one dive tender, as well as badly...
type of short, optional deep decompression stop performed by scuba divers at depths well below the first decompression stop mandated by a conventional...
scuba divers when ascending to the surface and is a potential cause of decompression sickness. The process has also been described as the basis for the cracking...
be decompression dives. The distinction is between dives for which there is no obligatory decompression stop, and dives for which the decompression planning...
by using decompression gases with high PO2 increases decompression efficiency and allows shorter decompression stops. Reducing decompression time can...
conservative decompression schedule the risk of decompression sickness is significantly reduced, and the total time spent decompressing is minimised....
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