The implantable drug pump 11, further comprising a user programmable control mechanism coupled to the drug pump and effective to selectively control {TAIL ~ movement} of {HEAD ~ the at least one valve} between the open and closed positions 
The implantable drug pump 11 , further comprising a user programmable control mechanism coupled to the drug pump and effective to selectively control { TAIL ~ movement } of { HEAD ~ the at least one valve } between the open and closed positions
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH