Reduced gradient bubble model

rdf:langString Reduced gradient bubble model

rdf:langString The reduced gradient bubble model (RGBM) is an algorithm developed by for calculating decompression stops needed for a particular dive profile. It is related to the Varying Permeability Model. but is conceptually different in that it rejects the gel-bubble model of the varying permeability model. It is used in several dive computers, particularly those made by Suunto, Aqwary, Mares, HydroSpace Engineering, 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. Some manufacturers such as Suunto have 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. The model has been correlated and validated in a number of published articles using collected dive profile data.