Miniature implanted drug delivery devices and inserter systems for introducing such devices

Abstract

A system (10, 200) and corresponding method for introducing a drug delivery device (18, 218) through at least part of a biological barrier starts with the drug delivery device (18, 218) deployed within a channel of a hollow needle (12, 212). The hollow needle is inserted into the biological barrier and the drug delivery device is pushed forward by a suitable plunger. The drug delivery device is preferably anchored to the biological barrier through a radially expanding retention arrangement (36, 36′, 36a), and is preferably filled with a liquid drug after deployment via a filling needle (24, 222) extending within the channel of the hollow needle (12, 212).

What is claimed is: 
     
         1 . A method for introducing a drug delivery device, the method comprising the steps of:
 (a) inserting the drug delivery device via a channel of a hollow needle through at least part of at least one layer of a biological barrier; and   (b) subsequent to said inserting, filling the drug delivery device with a quantity of liquid drug via a filling needle extending within the channel of the hollow needle.   
     
     
         2 . The method of  claim 1 , wherein the drug delivery device comprises a reservoir and a proximal filling port deployed to allow introduction of a volume of a liquid drug into said reservoir to be released over a period of time, and wherein said inserting and filling are performed using a system comprising:
 (a) a hollow needle having a central channel and a tip, the drug delivery device being deployed within said central channel of said hollow needle;   (b) a plunger displaceable so as to push the drug delivery device along said central channel and beyond said tip of said hollow needle; and   (c) a liquid injection device including a filling needle extending within said central channel of said hollow needle for engaging said filling port so as to allow filling of said reservoir after at least part of said reservoir has been advanced beyond said hollow needle.   
     
     
         3 . The method of  claim 2 , wherein said reservoir is an inflatable reservoir sized for deployment within said central channel when substantially empty and inflatable by filling with a liquid drug to assume a deployed size greater than dimensions of said central channel. 
     
     
         4 . The method of  claim 2 , wherein said filling needle extends through at least part of said plunger such that said filling needle engages said filling port prior to said inserting of said drug delivery device. 
     
     
         5 . The method of  claim 2 , wherein said drug delivery device deployed within said hollow needle, said plunger, said filling needle and said liquid injection device pre-filled with a quantity of a liquid drug, are preassembled into a single integrated delivery system for implanting and filling said drug delivery device within the body. 
     
     
         6 . The method of  claim 2 , wherein said tip of said hollow needle is a beveled tip terminating at a point for introducing said drug delivery device into the biological barrier without formation of a prior incision. 
     
     
         7 . The method of  claim 2 , further comprising an abutment surface surrounding at least part of said hollow needle so as to define a depth of penetration, and wherein said plunger has a predefined fully-advanced position, such that, after penetration of said tip into or through the biological barrier and advancing of said plunger, said drug delivery device extends to a predefined depth into the body. 
     
     
         8 . The method of  claim 2 , wherein said drug delivery device includes a radially expandable retention configuration configured to anchor said drug delivery device relative to a layer or layers of the biological barrier. 
     
     
         9 . The method of  claim 2 , wherein said drug delivery device includes a resiliently compressible retention configuration configured to anchor said drug delivery device relative to a layer or layers of the biological barrier. 
     
     
         10 . The method of  claim 1 , wherein the biological barrier includes the ocular sclera. 
     
     
         11 . A system for filling an implanted drug delivery device with a liquid, the system comprising:
 (a) a syringe comprising a syringe body for receiving a quantity of the liquid, a filling needle and a plunger;   (b) a pressure measurement arrangement associated with the syringe for measuring a pressure of the liquid within the syringe; and   (c) a processing system comprising a processor, the processing system being associated with said pressure measurement arrangement so as to receive fluid pressure measurements, wherein said processing system is configured to process said fluid pressure measurements to monitor for at least one alarm criteria.   
     
     
         12 . The system of  claim 11 , wherein said at least one alarm criteria includes the measured pressure dropping below a threshold minimum value. 
     
     
         13 . The system of  claim 11 , wherein said at least one alarm criteria includes the measured pressure exceeding a threshold maximum allowed value. 
     
     
         14 . The system of  claim 11 , wherein said processing system is configured to generate a warning under conditions of said alarm criteria. 
     
     
         15 . The system of  claim 11 , further comprising a display associated with said processor, and wherein said processing system is configured to determine from the measured pressure a quantity of the liquid within the drug delivery device, and to display on said display an indication of the quantity of the liquid within the drug delivery device. 
     
     
         16 . A method for filling an implanted drug delivery device with a liquid, the method comprising:
 (a) providing the system of  claim 11  containing a quantity of the liquid;   (b) inserting the filling needle into the drug delivery device and advancing the plunger of the syringe; and   (c) monitoring an output of the processing system for an indication of the at least one alarm condition.   
     
     
         17 . The method of  claim 16 , further comprising interrupting advancing of the plunger to allow measurement of the liquid pressure under zero-flow conditions.