{HEAD ~ A part} of the signal processing circuit connected to the probe is isolated by {TAIL ~ an isolation circuit} to secure the safety 
is isolated by
{ HEAD ~ A part } of the signal processing circuit connected to the probe is isolated by { TAIL ~ an isolation circuit } to secure the safety
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH