Multi-reservoir implantable pump with variable flow rate capabilities

Abstract

A multiple reservoir or chambered implantable pumps is disclosed. The pump according to the present invention is particularly useful in allowing for multiple constant flow rates to be provided from an otherwise constant flow implantable pump. The pump is also useful in allowing for housing of multiple active substances. A multiple reservoir implantable pump is also disclosed, which has at least one chamber capable of providing a constant flow rate and at least one chamber capable of being utilized for patient controlled injections. Methods of providing active substances to patients utilizing such pumps are also disclosed.

1 . A method of providing different constant flow rates of an active substance to a patient comprising the steps of:
 providing an implantable device having at least first and second active substance chambers; and   filling at least one of said first and second chambers or both of said chambers with said active substance in order to provide a selected flow rate of said active substance to said patient,   wherein filling only said first chamber with said active substance provides a first flow rate of said active substance, filling only said second chamber with said active substance provides a second flow rate of said active substance, and filling both said first and second chambers with said active substance provides a third flow rate of said active substance.   
     
     
         2 . The method according to  claim 1 , wherein said implantable device further includes an outlet in fluid communication with said active substance chambers. 
     
     
         3 . The method according to  claim 2 , wherein said implantable device further includes a first resistor in fluid communication between said first chamber and said outlet, and a second resistor in fluid communication between said second chamber and said outlet. 
     
     
         4 . The method according to  claim 1 , wherein said filling step includes utilizing a syringe to pierce a septum located over a replenishment opening associated with one of said first or second active substance chambers. 
     
     
         5 . The method according to  claim 1 , further comprising the step of filling a bolus port with said active substance to directly apply said active substance to said patient. 
     
     
         6 . The method according to  claim 1 , wherein said first and second chambers are filled with the same active substance. 
     
     
         7 . The method according to  claim 1 , wherein said first and second chambers are capable of being filled with different active substances. 
     
     
         8 . The method according to  claim 1 , wherein said filling step includes filling said first and second active substance chambers with two different active substances.