Catheter-Free Implantable Needle Biosensor

Abstract

Electrochemical biosensors consisting of two or more needle-shaped electrodes for monitoring of molecules such as glucose in the subcutaneous tissue are provided. The two electrodes are parallel to each other, and are fixed perpendicularly to the planar side of a sensor base which provides skin fixation and electric connection. The needle electrodes are made of rigid conducting materials, capable of inserting into the skin without the need of catheters. One electrode is the sensing electrode and the other, the reference electrode. A compound sensing membrane is attached onto the sensing electrode surface to detect analyzed molecules.

1 . An catheter-free subcutaneously implantable apparatus for producing a signal reflecting the concentration of molecules, said apparatus comprising: at least one needle shaped anode, at least one needle shaped cathode, a supporting base for mounting the anodes and the cathodes, and a contact means for connecting the anodes and the cathodes with a signal reading system. 
     
     
         2 . The apparatus of  claim 1 , wherein the molecules are glucose. 
     
     
         3 . The apparatus of  claim 2 , wherein the anode comprises a anode core, a first anode cover layer, a second anode cover layer, a third anode cover layer; wherein the cathode comprises a cathode core, a first cathode cover layer, a second cathode cover layer, a third cathode cover layer. 
     
     
         4 . The apparatus of  claim 3 , wherein the anode core is a metal core; the first anode cover layer is a noble metal layer; the second anode cover layer is a platinum layer, the third anode cover layer is a sensing layer; wherein the cathode core is a metal core, the first cathode cover layer is a silver layer, the second cathode cover layer is a silver chloride layer, and the third cathode cover layer is a polymer layer. 
     
     
         5 . The apparatus of  claim 4 , wherein the sensing layer is a compound membrane, including enzyme and biocompatible polymer material. 
     
     
         6 . The apparatus of  claim 5 , wherein the polymer material is medical grade polydimethylsiloxane copolymer. 
     
     
         7 . The apparatus of  claim 1 , wherein the supporting base is a molded insulating plastic base. 
     
     
         8 . The apparatus of  claim 7 , further comprises a mold plastic cover. 
     
     
         9 . The apparatus of  claim 8 , further comprises conducting circuits. 
     
     
         10 . The apparatus of  claim 8 , further comprises a circular medical adhesive tape. 
     
     
         11 . The apparatus of  claim 8 , wherein the contact means is an electric receptacle. 
     
     
         12 . The apparatus of  claim 1 , wherein the molecules are Oxygen. 
     
     
         13 . The apparatus of  claim 12 , wherein the anode comprises a anode core, a first anode cover layer, a second anode cover layer; wherein the cathode comprises a cathode core, a first cathode cover layer, and a second cathode cover layer. 
     
     
         14 . The apparatus of  claim 13 , wherein the anode core is a metal core; the first anode cover layer is a silver layer; the second anode cover layer is a polymer layer; wherein the cathode core is a metal core, the first cathode cover layer is a platinum layer, the second cathode cover layer is a biosensing layer. 
     
     
         15 . The apparatus of  claim 14 , wherein the biosensing layer is a complex membrane, including enzyme and biocompatible polymer materials. 
     
     
         16 . A percutaneously implanted miniature sensor assembly, comprising a base, an anode, a cathode, a first contact plate, and a second contact plate; wherein the base further comprises a first mounting hole surface, a second mounting hole surface, a base top surface and a base bottom surface, wherein the first mounting hole surface defines a first mounting hole, and the second mounting hole surface defines a second mounting hole; wherein the first contact plate further comprises a first plate mounting surface defining a first plate mounting hole, and the second contact plate further comprises a second plate mounting surface defining a second plate mounting hole respectively; wherein the first contact plate and the second contact plate are set on the base on the base top surface, wherein the first plate mounting hole, the second plate mounting hole are in line with the first mounting hole and the second mounting hole respectively; wherein the anode and cathode are in needle shape and implantable in a body, wherein the anode body penetrate the first plate mounting hole and the first mounting hole, and the cathode body penetrate the second plate mounting hole and the second mounting hole, wherein the top of the anode and cathode are connected with the first contact plate and the second contact plate by electric conductive material, wherein the anode and the cathode are perpendicular to the base bottom surface. 
     
     
         17 . A percutaneously implanted miniature sensor assembly as claimed in  claim 16 , wherein the anode comprises a anode core, a first anode cover layer, a second anode cover layer, a third anode cover layer; wherein the cathode comprises a cathode core, a first cathode cover layer, a second cathode cover layer, a third cathode cover layer. 
     
     
         18 . A percutaneously implanted miniature sensor assembly as claimed in  claim 17 , wherein the anode core is a metal core; the first anode cover layer is a noble metal layer; the second anode cover layer is a platinum layer, the third anode cover layer is a sensing layer; wherein the cathode core is a metal core, the first cathode cover layer is a silver layer, the second cathode cover layer is a silver chloride layer, and the third cathode cover layer is a polymer layer. 
     
     
         19 . The apparatus of  claim 18 , wherein the biosensing layer is a complex membrane, including enzyme and biocompatible polymer materials.