6Rapp R P,Bivins B A,Littrell R A.Patient-controlled analgesia:areview of effectiveness of therapy and an evaluation of currentlyavailable devices[J].DICP,1989,23(11):899-904.
7Chung I S,Cho H S,Kim J A,et al.The flow rate of the elastomericballoon infusor is influenced by the internal pressure of the infusor[J].J Korean Med Sci,2001,16:702-706.