Device and method for determining analyte levels

Abstract

Devices and methods for determining analyte levels are described. The devices and methods allow for the implantation of analyte-monitoring devices, such as glucose monitoring devices that result in the delivery of a dependable flow of blood to deliver sample to the implanted device. The devices include unique architectural arrangement in the sensor region that allows accurate data to be obtained over long periods of time.

1 . An implantable device for measuring an analyte, the device comprising: 
 a sensor body comprising a sensor interface configured to measure an analyte;    an angiogenic layer disposed on at least a portion of the sensor interface; and    an anchoring material attached to the sensor body and configured for anchoring the sensor body to a host tissue,    wherein the angiogenic layer comprises a micro-geometry configured to create a new capillary bed in close proximity to the sensor interface.    
     
     
         2 . The device of  claim 1 , wherein the new capillary bed provides the sensor with an oxygen concentration comparable to that normally available to tissue comprised of living cells, and a glucose concentration comparable to that normally available to tissue comprised of living cells.  
     
     
         3 . The device of  claim 1 , wherein the anchoring material comprises at least one material selected from the group consisting of porous silicone, poly(ethylene terephthalate), surgical grade fabric, polyester, velour, expanded polytetrafluoroethylene, polytetrafluoroethylene felt, and polypropylene cloth.  
     
     
         4 . The device of  claim 1 , wherein the angiogenic layer comprises at least one material selected from the group consisting of polytetrafluoroethylene, hydrophilic polyvinylidene fluoride, mixed cellulose esters, polyvinylchloride, polypropylene, polysulfone, and polymethylmethacrylate.  
     
     
         5 . The device of  claim 4 , wherein the angiogenic layer comprises expanded polytetrafluoroethylene.  
     
     
         6 . The device of  claim 1 , further comprising an additional outermost layer, wherein the additional outermost layer comprises a woven material or a non-woven material.  
     
     
         7 . The device of  claim 6 , wherein the additional outermost layer comprises a low-density non-woven polyester.  
     
     
         8 . The device of  claim 1 , wherein the angiogenic layer comprises pores having pore sizes of from about 0.5 microns to about 20 microns.  
     
     
         9 . The device of  claim 8 , wherein the angiogenic layer comprises pores having pore sizes of from about 1.0 μm to about 10 μm.  
     
     
         10 . The device of  claim 8 , wherein the angiogenic layer comprises expanded polytetrafluoroethylene.  
     
     
         11 . The device of  claim 1 , wherein the angiogenic layer has a thickness of from about 10 microns to about 20 microns.  
     
     
         12 . The device of  claim 1 , wherein the sensor body is cylindrical.  
     
     
         13 . The device of  claim 1 , sensing interface comprises a dome.  
     
     
         14 . The device of  claim 1 , wherein the angiogenic layer and the anchoring material are the same.  
     
     
         15 . An implantable device for measuring an analyte, the device comprising: 
 a sensor body comprising a sensor configured to measure an analyte; and    a composite bilayer membrane comprising an angiogenic layer and a bioprotective membrane disposed on at least a portion of the sensor.    
     
     
         16 . The device of  claim 15 , wherein the bioprotective comprises pores having pore sizes of from about 0.1 microns to about 1.0 micron.  
     
     
         17 . The device of  claim 15 , wherein the bioprotective membrane comprises at least one material selected from the group consisting of polytetrafluoroethylene, polypropylene, polysulfone, and polyethylene terephthalate.  
     
     
         18 . The device of  claim 15 , wherein the angiogenic layer comprises expanded polytetrafluoroethylene.  
     
     
         19 . The device of  claim 15 , wherein the bioprotective layer comprises polyvinylpyrrolidone.  
     
     
         20 . The device of  claim 15 , wherein the bioprotective layer comprises a urethane hydrogel.  
     
     
         21 . An implantable device for measuring an analyte in a biological fluid, the device comprising: 
 a sensor body comprising a sensor interface;    an angiogenic layer disposed on at least a portion of the sensor interface; and    a material for anchoring the sensor body to a host tissue, wherein the implantable device comprises porous silicone.    
     
     
         22 . The device of  claim 21 , wherein the angiogenic layer and the material for anchoring the sensor body to a host tissue are the same.