Reduced size implantable pump

Abstract

A variable hydraulic resistor for use with implantable pumps is disclosed. The variable hydraulic resistor according to the present invention is particularly useful in varying the flow rate of a medication fluid from an otherwise constant flow implantable pump. An implantable pump is also disclosed, which does not require a complicated clinching system or the like, and which may include an undulating membrane and chamber design to reduce the height of the pump.

1 . A resistor for varying the flow rate of a fluid from a first point to a second point comprising:
 a capillary having an inner surface;   a flow control element received within said capillary, said element having an outer surface opposing said inner surface of said capillary defining therebetween a passage way for the flow of said fluid therethrough, said outer surface of said element moveable relative to said inner surface of said capillary to alter the flow of said fluid therethrough.   
     
     
         2 . The resistor according to  claim 1 , wherein movement of said inner surface of said capillary alters the size of said passageway. 
     
     
         3 . The resistor according to  claim 1 , wherein movement of said inner surface of said capillary alters the shape of said passageway. 
     
     
         4 . The resistor according to  claim 1 , wherein said flow control element is an elongated polymer filament having a cross sectional dimension, the filament capable of being elongated to reduce the cross sectional dimension. 
     
     
         5 . The resistor according to  claim 4 , wherein the filament is located centrally within said capillary. 
     
     
         6 . The resistor according to  claim 4 , wherein the filament is located eccentrically within said capillary. 
     
     
         7 . The resistor according to  claim 4 , wherein the filament has a uniform cross section along its length. 
     
     
         8 . The resistor according to  claim 7 , wherein the filament has a substantially circular cross section. 
     
     
         9 . The resistor according to  claim 4 , wherein the filament has a non-uniform cross section along its length. 
     
     
         10 . The resistor according to  claim 4 , further comprising means for elongating the filament. 
     
     
         11 . The resistor according to  claim 10 , wherein said means for elongating the filament includes at least two magnetic elements. 
     
     
         12 . The resistor according to  claim 10 , wherein said means for elongating the filament includes an axle. 
     
     
         13 . The resistor according to  claim 1 , wherein said flow control element is a first hollow cylinder having a threaded exterior surface and said capillary includes a threaded interior surface, said first hollow cylinder axially received within said capillary, wherein the threaded exterior surface of the first cylinder engages the threaded interior surface of the capillary. 
     
     
         14 . The resistor according to  claim 13 , wherein the axial movement of the first cylinder with respect to the capillary varies the flow rate of said active substance. 
     
     
         15 . The resistor according to  claim 1 , wherein said flow control element is a hollow tubular element having a cross section that is capable of being varied. 
     
     
         16 . The resistor according to  claim 15 , wherein the hollow tubular element is located centrally within said capillary. 
     
     
         17 . The resistor according to  claim 16 , wherein the hollow tubular element is located eccentrically within said capillary. 
     
     
         18 . The resistor according to  claim 1 , wherein said flow control element is an elongate insert having a longitudinally varying cross section along its length. 
     
     
         19 . The resistor according to  claim 1 , further comprising means for controlling the movement of said flow control element. 
     
     
         20 . The resistor according to  claim 19 , wherein the means for controlling are wireless. 
     
     
         21 . The resistor according to  claim 1 , wherein said resistor is adapted to be connected with an implantable device for dispensing an active substance to a patient.