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 including:
 one or more processors, 
 one or more memories coupled with the one or more processors, 
   a battery coupled to the one or more processors,
 an RF transmitter/receiver coupled to the one or more processors, and 
 a fixation element comprising an adhesive configured to secure the data processing unit to the skin surface; 
   a glucose sensor configured to generate electrical signals indicative of levels of glucose in an interstitial fluid, the glucose sensor including:
 a proximal portion electrically coupled to the one or more processors of the data processing unit, and 
 a distal portion configured to be inserted through the skin surface and in contact with the interstitial fluid, the distal portion including:
 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; 
 
   wherein the glucose sensor comprises a predictable in vivo sensitivity drift and the one or more memories have a drift profile stored thereon;   wherein the one or more memories store instructions which, when executed by the one or more processors determine a glucose level based on the electrical signals generated by the glucose sensor and the drift profile; and   wherein the glucose monitoring system does not require user-initiated calibration during a life of the glucose sensor extending between 3 and 14 days.   
     
     
         2 . The glucose monitoring system of  claim 1 , wherein the second electrode further comprises a counter electrode. 
     
     
         3 . The glucose monitoring system of  claim 1 , 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. 
     
     
         4 . The glucose monitoring system of  claim 3 , wherein the mass transport limiting layer comprises a zwitterionic moiety. 
     
     
         5 . The glucose monitoring system of  claim 3 , wherein the mass transport limiting layer comprises at least one of a poly(ethylene glycol) modifier, hydroxyl modifier, and polyhydroxyl modifier. 
     
     
         6 . 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. 
     
     
         7 . 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. 
     
     
         8 . The glucose monitoring system of  claim 7 , wherein the proximal portion of the glucose sensor comprises a second width, wherein the first width and the second width are substantially the same. 
     
     
         9 . The glucose monitoring system of  claim 1 , wherein the data processing unit further comprises a temperature detection section operatively coupled to the one or more processors. 
     
     
         10 . The glucose monitoring system of  claim 9 , wherein the instructions, when executed by the one or more processors, determine the glucose level based further on a temperature measurement determined by the temperature detection section. 
     
     
         11 . 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 one or more processors. 
     
     
         12 . The glucose monitoring system of  claim 1 , wherein the glucose sensor detects hydrogen peroxide to generate the electrical signals indicative of levels of glucose. 
     
     
         13 . The glucose monitoring system of  claim 1 , further comprising a receiver unit including:
 one or more receiver processors;   one or more receiver memories coupled with the one or more receiver processors;   a receiver RF receiver/transmitter coupled to the one or more receiver processors and configured to communicate with the RF receiver/transmitter of the data processing unit via a communication link; and   a battery coupled to the one or more receiver processors.   
     
     
         14 . The glucose monitoring system of  claim 13 , wherein the communication link uses a Bluetooth enabled communication protocol. 
     
     
         15 . The glucose monitoring system of  claim 13 , wherein the system is configured to provide an alarm when a glucose condition is detected based at least in part on the determined glucose level. 
     
     
         16 . The glucose monitoring system of  claim 15 , wherein the glucose condition comprises hypoglycemia. 
     
     
         17 . The glucose monitoring system of  claim 15 , wherein the glucose condition comprises hyperglycemia. 
     
     
         18 . The glucose monitoring system of  claim 15 , wherein the glucose condition comprises impending hypoglycemia. 
     
     
         19 . The glucose monitoring system of  claim 15 , wherein the glucose condition comprises impending hyperglycemia. 
     
     
         20 . The glucose monitoring system of  claim 15 , wherein the alarm comprises an auditory and visual alarm. 
     
     
         21 . The glucose monitoring system of  claim 14 , wherein the alarm comprises a vibratory and visual alarm. 
     
     
         22 . 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. 
     
     
         23 . The glucose monitoring system of  claim 22 , wherein the opening comprises a longitudinal opening having a u-shaped cross-section. 
     
     
         24 . The glucose monitoring system of  claim 22 , wherein the opening comprises a longitudinal opening having a v-shaped cross section. 
     
     
         25 . The glucose monitoring system of  claim 22 , wherein the opening comprises a longitudinal opening having a c-shaped cross section. 
     
     
         26 . The glucose monitoring system of  claim 22 , 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. 
     
     
         27 . The glucose monitoring system of  claim 26 , 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. 
     
     
         28 . The glucose monitoring system of  claim 27 , 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. 
     
     
         29 . The glucose monitoring system of  claim 28 , wherein the insertion device comprises a plastic. 
     
     
         30 . The glucose monitoring system of  claim 29 , wherein the insertion device is disposable.