Closed loop/semi-closed loop therapy modification system

Abstract

A closed loop/semi-closed loop infusion system provides therapy modification and safeguards against the over-delivery or under-delivery of insulin. A glucose sensor system is configured to obtain a measured blood glucose value. A controller is operationally connected with the glucose sensor system and configured to trigger an alarm based on a measured blood glucose value or amount of insulin delivered, selectively perform calibration of the glucose sensor system when the alarm is triggered, and adjust a therapy delivery parameter when the alarm is triggered, wherein the adjusted therapy delivery parameter is limited to be within a boundary. Thereafter, a delivery system delivers therapy at the adjusted therapy delivery parameter.

1 . A method for providing therapy modification in an infusion system, the method comprising:
 triggering an alarm based on a measured blood glucose value or amount of insulin delivered;   selectively performing calibration of a glucose sensor system when the alarm is triggered; and   adjusting a therapy delivery parameter when the alarm is triggered, wherein the adjusted therapy delivery parameter is limited to be within a boundary.   
     
     
         2 . The method of  claim 1 , further comprising delivering therapy at the adjusted therapy delivery parameter. 
     
     
         3 . The method of  claim 1 , wherein the alarm is triggered when the measured blood glucose value is not consistent with a target blood glucose value. 
     
     
         4 . The method of  claim 1 , wherein the alarm is triggered when the amount of insulin delivered is not consistent with an expected amount of delivered insulin. 
     
     
         5 . The method of  claim 1 , wherein selectively performing calibration of the glucose sensor system comprises:
 informing a user that calibration needs to be performed;   prompting the user to decide whether the calibration is to be performed;   performing the calibration if the user decides to perform the calibration; and   proceeding to adjust the therapy delivery parameter if the user decides not to perform the calibration.   
     
     
         6 . The method of  claim 5 , wherein the therapy delivery parameter is adjusted according to a default basal pattern if the user decides not to perform the calibration. 
     
     
         7 . The method of  claim 6 , wherein adjusting the therapy delivery parameter comprises:
 suspending closed-loop therapy delivery; and   reverting to open-loop therapy delivery using the default basal pattern.   
     
     
         8 . The method of  claim 7 , further comprising:
 resuming closed-loop therapy delivery if a condition triggering the alarm is corrected; and   continuing open-loop therapy delivery if the condition triggering the alarm is not corrected.   
     
     
         9 . The method of  claim 5 , further comprising:
 obtaining a measured blood glucose value after performing the calibration; and   comparing the measured blood glucose value to a target blood glucose value.   
     
     
         10 . The method of  claim 5 , further comprising:
 determining that a calibrated measured blood glucose value is not consistent with a target blood glucose value after performing the calibration; and   proceeding to adjust the therapy delivery parameter if the calibrated measured blood glucose value is not consistent with the target blood glucose value.   
     
     
         11 . The method of  claim 5 , further comprising proceeding to adjust the therapy delivery parameter if the user decides to perform the calibration at a later time. 
     
     
         12 . The method of  claim 2 , further comprising prompting a patient to accept the adjusted therapy delivery parameter prior to delivering the therapy. 
     
     
         13 . The method of  claim 1 , further comprising performing a safety action if the adjusted therapy delivery parameter exceeds the boundary. 
     
     
         14 . The method of  claim 1 , wherein the therapy delivery parameter is a basal rate. 
     
     
         15 . The method of  claim 1 , further comprising logging the adjusted therapy delivery parameter. 
     
     
         16 . The method of  claim 1 , wherein selectively performing calibration of the glucose sensor system further comprises obtaining a calibration value from a glucose meter. 
     
     
         17 . The method of  claim 1 , wherein the boundary comprises 25% above or below a preset basal rate. 
     
     
         18 . The method of  claim 1 , wherein the boundary comprises a maximum allowed increase or decrease of a preset basal rate. 
     
     
         19 . The method of  claim 18 , wherein an absolute value of the maximum allowed increase does not equal an absolute value of the maximum allowed decrease. 
     
     
         20 . An infusion system for providing therapy modification, the system comprising:
 a glucose sensor system; and   a controller operationally connected with the glucose sensor system, wherein the controller triggers an alarm based on a measured blood glucose value or amount of insulin delivered, selectively performs calibration of the glucose sensor system when the alarm is triggered, and adjusts a therapy delivery parameter when the alarm is triggered, wherein the adjusted therapy delivery parameter is limited to be within a boundary.   
     
     
         21 . The system of  claim 20 , further comprising a delivery system operationally connected with the controller and configured to deliver therapy at the adjusted therapy delivery parameter. 
     
     
         22 . The system of  claim 20 , wherein the controller triggers the alarm when the measured blood glucose value is not consistent with a target blood glucose value. 
     
     
         23 . The system of  claim 20 , wherein the controller triggers the alarm when the amount of insulin delivered is not consistent with an expected amount of delivered insulin. 
     
     
         24 . The system of  claim 20 , wherein the controller selectively performs calibration of the glucose sensor system by:
 informing a user that calibration needs to be performed;   prompting the user to decide whether the calibration is to be performed;   performing the calibration if the user decides to perform the calibration; and   proceeding to adjust the therapy delivery parameter if the user decides not to perform the calibration.   
     
     
         25 . The system of  claim 24 , wherein the controller adjusts the therapy delivery parameter according to a default basal pattern if the user decides not to perform the calibration. 
     
     
         26 . The system of  claim 25 , wherein the controller adjusts the therapy delivery parameter by:
 suspending closed-loop therapy delivery; and   reverting to open-loop therapy delivery using the default basal pattern.   
     
     
         27 . The system of  claim 26 , wherein the controller:
 resumes closed-loop therapy delivery if a condition triggering the alarm is corrected; and   continues open-loop therapy delivery if the condition triggering the alarm is not corrected.   
     
     
         28 . The system of  claim 24 , wherein the controller obtains a measured blood glucose value after performing the calibration, and compares the measured blood glucose value to a target blood glucose value. 
     
     
         29 . The system of  claim 24 , wherein the controller determines that a calibrated measured blood glucose value is not consistent with a target blood glucose value after performing the calibration, and proceeds to adjust the therapy delivery parameter if the calibrated measured blood glucose value is not consistent with the target blood glucose value. 
     
     
         30 . The system of  claim 24 , wherein the controller proceeds to adjust the therapy delivery parameter if the user decides to perform the calibration at a later time. 
     
     
         31 . The system of  claim 21 , wherein the controller prompts a patient to accept the adjusted therapy delivery parameter prior to delivering the therapy. 
     
     
         32 . The system of  claim 20 , wherein the controller performs a safety action if the adjusted therapy delivery parameter exceeds the boundary. 
     
     
         33 . The system of  claim 20 , wherein the therapy delivery parameter is a basal rate. 
     
     
         34 . The system of  claim 20 , wherein the controller logs the adjusted therapy delivery parameter. 
     
     
         35 . The system of  claim 20 , wherein selectively performing calibration of the glucose sensor system further comprises obtaining a calibration value from a glucose meter. 
     
     
         36 . The system of  claim 20 , wherein the boundary comprises 25% above or below a preset basal rate. 
     
     
         37 . The system of  claim 20 , wherein the boundary comprises a maximum allowed increase or decrease of a preset basal rate. 
     
     
         38 . The system of  claim 37 , wherein an absolute value of the maximum allowed increase does not equal an absolute value of the maximum allowed decrease.