Where does decompression collide?

In diving physiology, decompression is the controlled reduction of ambient pressure during ascent, paced so that inert gas dissolved in the tissues under pressure can leave through the lungs without forming damaging bubbles. Boycott, Damant, and Haldane's 1908 The prevention of compressed-air illness founded the field by showing that a diver can tolerate a limited pressure-ratio drop and introducing staged, stop-based ascent schedules. The referent is the scheduled lowering of pressure to let a dissolved gas load dissipate: an act of letting pressure out, which shares only its name with reconstructing compressed data or relieving pressure on a nerve.[1]

Unit

The ascent schedule (stop depths and times) that keeps tissue gas tension safe

Recovery means

Tissues return to equilibrium as dissolved inert gas is eliminated without bubble formation

Measured by

Specified by decompression tables or algorithms giving stop depths and durations for a given exposure

In surgery, decompression is a procedure that relieves damaging mechanical pressure on a confined anatomical structure (opening the skull to let a swollen brain expand, freeing a trapped nerve, or widening a stenotic spinal canal). Cooper and colleagues' 2011 Decompressive craniectomy in diffuse traumatic brain injury is a paradigm trial of the approach, removing part of the skull to lower intracranial pressure after severe injury. The referent is the surgical release of pressure to protect tissue, measured by the pressure fall and clinical outcome achieved, unrelated to a dive ascent schedule or a data decoder apart from the common meaning of taking pressure off.[2]

Unit

The reduction in pressure on the structure and the clinical outcome it secures

Recovery means

The compressed structure recovers function as sustained pressure on it is relieved

Measured by

Judged by the measured pressure drop (e.g. intracranial pressure) and by functional outcome after the procedure