The pressure supply conduit communicates with {HEAD ~ an external source} of {TAIL ~ air}, or a detachable cartridge of a biologically compatible compressed gas 
of
The pressure supply conduit communicates with { HEAD ~ an external source } of { TAIL ~ air } , or a detachable cartridge of a biologically compatible compressed gas
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH