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