Medical sensor system for detecting a feature in a body

Abstract

The invention relates to a medical sensor system ( 10 ) for detecting a feature ( 12 ), such as an analyte, in a human or animal body. The system ( 10 ) includes at least one sensor ( 14; 34 ) having a reservoir ( 18 ) with a cap ( 16 ) designed as a controllable organic membrane ( 20 ), wherein (for example) application of a voltage of a particular magnitude, or application of a voltage for a particular time, effects a change in the permeability of the membrane ( 20 ).

What is claimed is: 
     
         1 . A medical sensor system for detecting a feature of an analyte in a body, the system including:
 a. a reservoir having a reservoir interior sample volume bounded by a reservoir wall, the reservoir wall:
 (1) isolating the reservoir interior sample volume from a reservoir exterior, and 
 (2) including a reservoir cap defined by an organic membrane having pores therein, the pores having controllably adjustable pore sizes, whereby the pore sizes are adjustable to selectively allow or prohibit passage of the analyte through the pores from the reservoir exterior to the reservoir interior sample volume; 
   b. a sensor situated within the reservoir interior sample volume, the sensor being configured to detect the feature of the analyte.   
     
     
         2 . The medical sensor system of  claim 1  wherein the pore sizes are continuously adjustable between:
 a. a closed state wherein the pores are closed, and 
 b. a fully open state wherein the pores have maximum pore sizes. 
 
     
     
         3 . The medical sensor system of  claim 1  wherein the pore sizes are reversibly adjustable from:
 a. a closed state wherein the pores are closed, to 
 b. a fully open state wherein the pores have maximum pore sizes, and from the fully open state to the closed state. 
 
     
     
         4 . The medical sensor system of  claim 1  wherein the membrane is at least partially formed of a material having a changeable redox state. 
     
     
         5 . The medical sensor system of  claim 1  wherein the pore sizes of the membrane are electrically controllable. 
     
     
         6 . The medical sensor system of  claim 1  wherein the membrane includes a carrier structure having apertures of fixed size defined therein. 
     
     
         7 . The medical sensor system of  claim 6  wherein the carrier structure has a material with a changeable redox state thereon. 
     
     
         8 . The medical sensor system of  claim 6  wherein the carrier structure has an electroactive polymer thereon, the electroactive polymer having the pores defined therein. 
     
     
         9 . The medical sensor system of  claim 8  wherein the electroactive polymer includes one or more of:
 a. polypyrrole (PPy), and 
 b. dodecylbenzene sulfonic acid (DBS). 
 
     
     
         10 . The medical sensor system of  claim 6  wherein the carrier structure has titanium dioxide therein. 
     
     
         11 . The medical sensor system of  claim 6  wherein the apertures are defined by nanotubes. 
     
     
         12 . The medical sensor system of  claim 6  wherein:
 a. the apertures have inner surfaces bearing a conductor thereon, and 
 b. the inner surfaces and conductors have an electroactive polymer thereon, the electroactive polymer having the pores defined therein. 
 
     
     
         13 . The medical sensor system of  claim 1  in combination with one or more of the following implants:
 a. a drug delivery system, 
 b. a stent, 
 c. a pacemaker, 
 d. a defibrillator, 
 e. an artificial valve, 
 whereupon the medical sensor system is located. 
 
     
     
         14 . The medical sensor system of  claim 1  wherein the reservoir wall includes:
 a. the cap; 
 b. a reservoir base opposite the cap, whereupon the sensor is provided; and 
 c. reservoir sides extending between the cap and the reservoir base. 
 
     
     
         15 . The medical sensor system of  claim 14  in combination with a medical implant, wherein the medical sensor is provided on a surface of the medical implant with:
 a. the reservoir base situated adjacent the surface of the medical implant, and 
 b. the cap situated distant from the surface of the medical implant. 
 
     
     
         16 . The medical sensor system of  claim 15 , wherein the medical implant includes several of the medical sensor provided on the surface of the medical implant. 
     
     
         17 . A medical sensor system for detecting a feature of an analyte in a body, the system including:
 a. a reservoir having a reservoir cap thereon, wherein:
 (1) the reservoir and reservoir cap:
 (a) bound a reservoir interior sample volume, and 
 (b) isolate the reservoir interior sample volume from the reservoir exterior; 
 
 (2) the cap includes:
 (a) a carrier structure having apertures of fixed size defined therein; 
 (b) a conductor situated on the inner surfaces of the apertures; 
 (c) an electroactive material on the inner surfaces and conductors, the electroactive material having pores extending through the reservoir cap; 
 wherein application of electricity to the conductor induces a change in the sizes of the pores of the electroactive material between: 
 i. a closed state wherein the pores are closed, with the cap thereby separating the reservoir interior sample volume from the reservoir exterior, and 
 ii. a fully open state wherein the pores have maximum pore sizes, with the pores thereby exposing the reservoir interior sample volume to the reservoir exterior; and 
 
   b. a sensor situated within the reservoir interior sample volume.   
     
     
         18 . The medical sensor system of  claim 17  wherein the apertures of fixed size are defined by nanotubes. 
     
     
         19 . The medical sensor system of  claim 17  wherein the electroactive material is a polymer configured to change its redox state upon the application of electricity. 
     
     
         20 . The medical sensor system of  claim 17 :
 a. wherein the reservoir includes:
 (1) a reservoir base opposite the reservoir cap, with the sensor being provided on the reservoir base, and 
 (2) reservoir sides extending between the cap and the reservoir base; 
   b. in combination with a medical implant, wherein the medical sensor is provided on a surface of the medical implant with:
 (1) the reservoir base situated adjacent the surface of the medical implant, and 
 (2) the cap situated distant from the surface of the medical implant.