Decompression (diving) but in later experiments signs of what was later to become known as decompression sickness were observed. Later, when technological advances allowed the use of pressurization of mines and caissons to exclude water ingress, miners were observed to present symptoms of what would become known as caisson disease, compressed air illness, the bends, and decompression sickness. Once it was recognized that the symptoms were caused by gas bubbles, and that re-compression could relieve the symptoms, Paul Bert showed in 1878 that decompression sickness is caused by nitrogen bubbles released from tissues and blood during or after decompression, and showed the
Oxygen window in diving decompression at a shallower stop at the same risk, or at the same rate at the same depth at a lower risk, or at an intermediate rate at an intermediate depth at an intermediate risk. Use of 100% oxygen is limited by oxygen toxicity at deeper depths. Convulsions are more likely when the pO exceeds . Technical divers use gas mixes with high ppO in some sectors of the decompression schedule. As an example, a popular decompression gas is 50% nitrox on decompression stops starting at . Where to add the high ppO gas in the schedule depends on what limits