Reduced gradient bubble model

The reduced gradient bubble model (RGBM) is an algorithm developed by Dr Bruce Wienke for calculating decompression stops needed for a particular dive profile. It is based on the Varying Permeability Model.^[1]

The full model is only used by the HS Explorer dive computer. ^[1] Approximations of the model are used in several dive computers, particularly those made by Suunto, Mares, and Underwater Technologies Center.^[2] It is characterised by the following assumptions: blood flow (perfusion) provides a limit for tissue gas penetration by diffusion; an exponential distribution of sizes of bubble seeds is always present, with many more small seeds than large ones; bubbles are permeable to gas transfer across surface boundaries under all pressures; the haldanean tissue compartments range in half time from 1 to 720 minutes, depending on gas mixture.^[1]

Manufacturers such as Suunto have also devised approximations of Wienke's model. Suunto uses a modified haldanean nine-compartment model with the assumption of reduced off-gassing caused by bubbles. This implementation offers both a depth ceiling and a depth floor for the decompression stops. The former maximises tissue off-gassing and the latter minimises bubble growth.^[3]

References

^ ^a ^b ^c Wienke, Bruce R; O’Leary (13 February 2002). "Reduced gradient bubble model: Diving algorithm, basis and comparisons" (PDF). Tampa, Florida: NAUI Technical Diving Operations. pp. 7–12. Retrieved 12 January 2010. {{cite web}}: Text "first2-Timothy R" ignored (help)
^ "Dive Computer". Retrieved 12 January 2010.
^ "Suunto Reduced Gradient Bubble Model" (PDF). Suunto. 24 July 2003. Retrieved 24 January 2010.

External links

Campbell, Ernest S (30 April 2009). "Reduced gradient bubble model". Scubadoc's Diving Medicine. Retrieved 12 January 2010. – Bruce Wienke describes the differences between RGBM and VPM

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[wienke2002-1] Wienke, Bruce R; O’Leary (13 February 2002). "Reduced gradient bubble model: Diving algorithm, basis and comparisons" (PDF). Tampa, Florida: NAUI Technical Diving Operations. pp. 7–12. Retrieved 12 January 2010. {{cite web}}: Text "first2-Timothy R" ignored (help)

[utc-2] "Dive Computer". Retrieved 12 January 2010.

[suunto2003-3] "Suunto Reduced Gradient Bubble Model" (PDF). Suunto. 24 July 2003. Retrieved 24 January 2010.

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v t e Diving decompression
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Algorithms	Bühlmann decompression algorithm Haldane's decompression model Reduced gradient bubble model Thalmann algorithm Thermodynamic model of decompression Varying Permeability Model
Diving	Deep diving Professional diving Recreational diving Saturation diving Scuba diving Technical diving Underwater diving
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Injury and treatment	Decompression sickness Diving chamber Hyperbaric medicine Hyperbaric treatment schedules In-water recompression
Procedures	Pyle stop Ratio decompression
Categories: Underwater diving decompression Commons: Category:Decompression