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]
It is used in several dive computers, particularly those made by Suunto, Mares, HydroSpace Engineering,[1] and Underwater Technologies Center. 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.[2]
|
||||||||||||||||||||