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 method of determining a glucose level, comprising:
 providing glucose monitoring system including
 a data processing unit configured for mounting on a skin surface, the data processing unit including
 one or more processors, 
 one or more memories coupled with the one or more processors, 
 
 the one or more memories having a drift profile stored thereon, wherein the drift profile is time dependent,
 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 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 an interstitial fluid, 
 
 wherein the glucose sensor is configured to generate electrical signals indicative of levels of glucose in the interstitial fluid, and the glucose monitoring system does not require user-initiated calibration during a life of the glucose sensor extending between 3 and 14 days; 
   causing the glucose sensor to extend through the skin surface such that the distal portion placed in contact with the interstitial fluid;   receiving a signal from the glucose sensor;   determining a drift correction factor based on the drift profile;   determining a glucose level based on the signal from the glucose sensor and the drift correction factor; and   transmitting the glucose level to a receiving device for display to a user.   
     
     
         2 . The method of  claim 1 , further comprising
 detecting a glucose condition based at least in part on the determined glucose level; and   providing an alarm when the glucose condition is detected.   
     
     
         3 . The method of  claim 2 , wherein the glucose condition comprises hypoglycemia. 
     
     
         4 . The method of  claim 2 , wherein the glucose condition comprises hyperglycemia. 
     
     
         5 . The method of  claim 2 , wherein the glucose condition comprises impending hypoglycemia. 
     
     
         6 . The method of  claim 2 , wherein the glucose condition comprises impending hyperglycemia. 
     
     
         7 . The method of  claim 2 , wherein the alarm comprises an auditory and visual alarm. 
     
     
         8 . The method of  claim 2 , wherein the alarm comprises a vibratory and visual alarm. 
     
     
         9 . The method of  claim 1 , further comprising
 detecting a rate of change of glucose; and   providing an alert when the rate of change of glucose exceeds a threshold.   
     
     
         10 . The method of  claim 1 , further comprising
 detecting an acceleration of a rate of change of glucose; and   providing an alert when the acceleration of the rate of change of glucose exceeds a threshold.   
     
     
         11 . The method of  claim 1 , wherein determining a glucose level is further based on a relationship of blood to subcutaneous tissue glucose. 
     
     
         12 . The method of  claim 1 , wherein determining a glucose level is further based on a temperature measurement. 
     
     
         13 . The method of  claim 1 , wherein the drift profile provides an in vivo sensor sensitivity drift percentage over a period of time. 
     
     
         14 . The method of  claim 1 , wherein the drift profile corresponds to an algorithm. 
     
     
         15 . The method of  claim 1 , wherein the drift profile accounts for a change in sensitivity over an initial 12-14 hours of operation of the sensor after causing the glucose sensor to extend through the skin surface. 
     
     
         16 . The method of  claim 16 , wherein the drift profile accounts for early signal attenuation.