INSERTION SITE MONITORING METHODS AND RELATED INFUSION DEVICES AND SYSTEMS

• US 20180177946A1
• Filed: 12/22/2016
• Published: 06/28/2018
• Est. Priority Date: 12/22/2016
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Loutseiko, Mikhail, Roy, Anirban, Grosman, Benyamin, Wu, Di, Gottlieb, Rebecca K., Parikh, Neha J.
• Granted Patent: US 10,272,201 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61M 2005/14208 with a programmable infusion control system, characterised by the infusion program
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/52 with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: A61M 2230/201 Glucose concentration
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/16836 by sensing tissue properties at the infusion site, e.g. for detecting infiltration detecting tissue temperature for diagnostic purposes A61M39/0247
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: G16H 20/17 delivered via infusion or injection
• CPC Class Codes: G16H 40/63 for local operation

Abstract

Infusion systems, infusion devices, and related operating methods are provided. An exemplary method of operating an infusion device involves obtaining one or more measurement values of a physiological condition in the body of a user during an initial monitoring period and determining a fasting reference value for a metric based on the one or more measurement values. After the initial monitoring period, the method continues by obtaining an updated measurement value during a fasting period, determining a current value for the metric based at least in part on the updated measurement value, and generating a notification in response to a deviation between the current value and the fasting reference value exceeding a threshold indicative of insertion site loss or other loss of effectiveness.

Claims

1. A method of operating an infusion device operable to deliver a fluid influencing a physiological condition to a body of a user, the method comprising:

obtaining, from a sensing arrangement providing sensed measurements of the physiological condition in the body of the user, one or more measurement values during an initial monitoring period;

determining a fasting reference value for a metric based on the one or more measurement values; and

after the initial monitoring period;

obtaining, from the sensing arrangement, an updated measurement value during a fasting period;

determining a current value for the metric based at least in part on the updated measurement value; and

generating a notification in response to a deviation between the current value and the fasting reference value exceeding a threshold.

2. The method of claim 1, further comprising identifying one or more fasting periods during the initial monitoring period, wherein obtaining the one or more measurement values comprises obtaining the one or more measurement values of the sensed measurements corresponding to a respective one of the one or more fasting periods.

3. The method of claim 1, wherein:

determining the fasting reference value comprises;

determining a fasting value for the physiological condition based on the one or more measurement values; and

determining an estimated amount of the fluid for achieving a reference value for the physiological condition based at least in part on the fasting value;

determining the current value for the metric comprises determining a second estimated amount of the fluid for achieving the reference value for the physiological condition based at least in part on the updated measurement value; and

generating the notification comprises generating the notification when a difference between the second estimated amount and the estimated amount exceeds the threshold.

4. The method of claim 3, further comprising determining a current amount of the fluid in the body of the user during the fasting period coincident with the updated measurement value, wherein determining the second estimated amount comprises determining the second estimated amount of the fluid for achieving the reference value based at least in part on the updated measurement value and the current amount of the fluid.

5. The method of claim 4, further comprising determining an estimated fasting amount of the fluid active in the body of the user during the initial monitoring period coincident with the one or more measurement values, wherein determining the estimated amount of the fluid for achieving the reference value comprises determining the estimated amount based at least in part on the fasting value and the estimated fasting amount of the fluid.

6. The method of claim 1, wherein:

determining the fasting reference value comprises averaging the one or more measurement values to obtain an average measurement value; and

generating the notification comprises generating the notification when a difference between the current value and the average measurement value exceeds the threshold.

7. The method of claim 6, further comprising identifying one or more fasting periods during the initial monitoring period, wherein obtaining the one or more measurement values comprises obtaining the one or more measurement values of the sensed measurements corresponding to a respective one of the one or more fasting periods.

8. The method of claim 1, further comprising verifying deviations in the physiological condition in the body of the user are less than a second threshold prior to identifying the fasting period.

9. The method of claim 1, further comprising verifying normal operation of the infusion device prior to identifying the fasting period.

10. A computer-readable medium having computer-executable instructions stored thereon that, when executed by a processing system of an electronic device, cause the processing system to perform the method of claim 1.

11. A method of operating an infusion device operable to deliver insulin to a body of a patient, the method comprising:

obtaining, from a sensing arrangement, sensed glucose measurement values of a glucose level in the body of the patient during fasting periods during an initial period after initialization of an infusion set associated with the infusion device;

determining a fasting amount of insulin in the body of the patient during the fasting periods;

determining a reference insulin estimate for achieving a reference glucose value based at least in part on the fasting amount of insulin and the sensed glucose measurement values; and

after the initial period;

obtaining, from the sensing arrangement, an updated glucose measurement value during a subsequent fasting period;

determining a current amount of insulin in the body of the patient;

determining a current insulin estimate for achieving the reference glucose value based at least in part on the current amount of insulin and the updated glucose measurement value; and

generating an insertion site notification based on a relationship between the current insulin estimate and the reference insulin estimate.

12. The method of claim 11, further comprising determining the current amount of insulin based on historical delivery data corresponding to preceding operation of the infusion device to deliver the insulin to the body of the patient.

13. The method of claim 12, further comprising determining a total daily insulin value based on the historical delivery data, wherein determining the current insulin estimate comprises calculating the current insulin estimate based on the updated glucose measurement value, the reference glucose value, the current amount of insulin, and the total daily insulin value.

14. The method of claim 12, further comprising verifying the glucose level in the body of the patient is stable prior to obtaining the sensed glucose measurement values.

15. The method of claim 12, further comprising verifying normal operation of the infusion device prior to obtaining the sensed glucose measurement values.

16. The method of claim 12, further comprising verifying absence of a meal within a threshold time period prior to obtaining the sensed glucose measurement values.

17. The method of claim 16, further comprising verifying the glucose level in the body of the patient is stable prior to obtaining the sensed glucose measurement values.

18. The method of claim 16, further comprising verifying absence of a meal within the threshold time period prior to obtaining the updated glucose measurement value.

19. An infusion device comprising:

a communications interface to receive sensed measurements of a physiological condition in a body of a user;

a fluid interface providing fluid communication with an infusion set to deliver fluid influencing the physiological condition to the body of the user;

a user interface; and

a control module coupled to the communications interface and the user interface to;

obtain one or more fasting measurement values for the physiological condition from the sensed measurements corresponding to fasting periods during an initial period of a lifetime of the infusion set;

determine a fasting reference value for a metric based on the one or more fasting measurement values; and

after the initial period;

obtain an updated measurement value from the sensed measurements corresponding to a subsequent fasting period;

determine a current value for the metric based at least in part on the updated measurement value; and

provide a notification via the user interface based on a difference between the current value and the fasting reference value.

20. The infusion device of claim 19, further comprising a data storage element coupled to the control module to maintain the fasting reference value for the metric.