Risk of Central Nervous System Decompression Sickness in Air Diving to No-Stop Limits

摘要

Current U.S. Navy Air and N2-O2 decompression procedures are calculated by using the Thalmann Algorithm with the VVal-18 or VVal-18m parameter sets. Recent man-testing at the Navy Experimental Diving Unit (NEDU) of the VVal-18 air no-stop limits at 130, 150 and 190 feet of sea water resulted in incidents of severe central nervous system decompression sickness (CNSDCS). A logistic model of the probability of cnsDCS (P cnsDCS) in air no- stop dives from the recent NEDU man-testing and the USN primary n2-o2 data set was developed and used to produce a set of iso-risk air no-stop limits and estimated P cnsDCS of various air no-stop limits. A new parameter set (VVal-76) for the Thalmann Algorithm that produces air no-stop limits with P csnDCS near 0.002 was developed. Similar air no-stop limits are obtained by using the unmodified Navy Special Warfare version of the Navy Dive Computer (NSW III). The NSW III is recommended for no-stop air diving.