Continuous analyte measurement systems and systems and methods for implanting them

Abstract

Low profile continuous analyte measurement systems and systems and methods for implantation within the skin of a patient are provided.

What is claimed is: 
     
         1 . A glucose monitoring system comprising:
 a data processing unit configured to be mounted on a skin surface and including
 a processor, 
 a transmitter, and 
 one or more memories coupled to the processor; and 
 a glucose sensor including a proximal portion electrically coupled to the processor of the data processing unit and a distal portion configured to be inserted through the skin surface and in contact with an interstitial fluid, wherein the glucose sensor is configured to generate electrical signals indicative of levels of glucose in the interstitial fluid; 
   wherein the glucose monitoring system is configured to determine a glucose level using at least a drift correction factor associated with the glucose sensor, the drift correction factor determined by the glucose monitoring system based at least in part on a drift profile;   wherein the drift profile is programmed into the one or more memories of the glucose monitoring system prior to insertion of the distal portion of the glucose sensor through the skin surface; and   wherein the glucose monitoring system is configured to provide an alarm when a glucose condition is detected based at least in part on the determined glucose level, the alarm being a vibratory and visual alarm.   
     
     
         2 . The glucose monitoring system of  claim 1 , wherein the alarm further comprises an auditory alarm. 
     
     
         3 . The glucose monitoring system of  claim 1 , wherein the glucose condition comprises hypoglycemia. 
     
     
         4 . The glucose monitoring system of  claim 1 , wherein the glucose condition comprises hyperglycemia. 
     
     
         5 . The glucose monitoring system of  claim 1 , wherein the glucose condition comprises impending hypoglycemia. 
     
     
         6 . The glucose monitoring system of  claim 1 , wherein the glucose condition comprises impending hyperglycemia. 
     
     
         7 . The glucose monitoring system of  claim 1 , wherein the glucose condition comprises a rate of change of the glucose level. 
     
     
         8 . The glucose monitoring system of  claim 1 , wherein the glucose condition comprises an acceleration of a rate of change of the glucose level. 
     
     
         9 . The glucose monitoring system of  claim 1 , wherein the distal portion of the sensor comprises:
 a plurality of electrodes including a working electrode and a second electrode, wherein the second electrode comprises a reference electrode, and   an enzyme comprising glucose oxidase disposed proximate the working electrode.   
     
     
         10 . The glucose monitoring system of  claim 9 , wherein the second electrode further comprises a counter electrode. 
     
     
         11 . The glucose monitoring system of  claim 10 , wherein the distal portion of the glucose sensor further comprises a mass transport limiting layer configured to reduce a rate of mass transport of glucose into a region proximate the working electrode. 
     
     
         12 . The glucose monitoring system of  claim 11 , wherein the mass transport limiting layer comprises a zwitterionic moiety. 
     
     
         13 . The glucose monitoring system of  claim 12 , wherein the mass transport limiting layer comprises at least one of a poly(ethylene glycol), hydroxyl, and polyhydroxyl modifier. 
     
     
         14 . The glucose monitoring system of  claim 1 , where the distal portion of the glucose sensor further comprises an interferent eliminating layer disposed between the working electrode and the glucose oxidase. 
     
     
         15 . The glucose monitoring system of  claim 1 , wherein the distal portion of the glucose sensor comprises a first width of 0.15 mm or less. 
     
     
         16 . The glucose monitoring system of  claim 15 , wherein the proximal portion of the glucose sensor comprises a second width, wherein the first width and the second width are substantially the same. 
     
     
         17 . The glucose monitoring system of  claim 1 , wherein the data processing unit further comprises a temperature detection section operatively coupled to the processor. 
     
     
         18 . The glucose monitoring system of  claim 9 , wherein the instructions, when executed by the processor, determine the glucose level based further on a temperature measurement determined by the temperature detection section. 
     
     
         19 . The glucose monitoring system of  claim 1 , where in the data processing unit further comprises a clock configured to supply real time information to the processor. 
     
     
         20 . The glucose monitoring system of  claim 1 , further comprising an insertion device having an insertion needle having an opening configured to receive the distal portion of the glucose sensor. 
     
     
         21 . The glucose monitoring system of  claim 20 , wherein the opening comprises a longitudinal opening having a u-shaped cross-section. 
     
     
         22 . The glucose monitoring system of  claim 20 , wherein the opening comprises a longitudinal opening having a v-shaped cross section. 
     
     
         23 . The glucose monitoring system of  claim 20 , wherein the opening comprises a longitudinal opening having a c-shaped cross section. 
     
     
         24 . The glucose monitoring system of  claim 20 , wherein the insertion device further comprises a body having a distal base portion, the distal base portion including a bottom surface configured for placement on the skin surface. 
     
     
         25 . The glucose monitoring system of  claim 24 , where in the insertion device further comprises a plunger positioned within the body and movable perpendicular to the skin surface, the plunger coupled to the insertion needle. 
     
     
         26 . The glucose monitoring system of  claim 25 , wherein the insertion device further comprises a spring providing a bias on the plunger to retract the insertion needle after the sensor is inserted through the skin surface. 
     
     
         27 . The glucose monitoring system of  claim 26 , wherein the insertion device comprises a plastic. 
     
     
         28 . The glucose monitoring system of  claim 27 , wherein the insertion device is disposable. 
     
     
         29 . The glucose monitoring system of  claim 1 , wherein the drift profile provides an in vivo sensor sensitivity drift percentage over a period of time. 
     
     
         30 . The glucose monitoring system of  claim 1 , wherein the drift profile accounts for a change in sensitivity over an initial 12-14 hours of operation of the sensor.