Method and/or system for multicompartment analyte monitoring

• US 9,854,998 B2
• Filed: 10/10/2014
• Issued: 01/02/2018
• Est. Priority Date: 10/26/2011
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Yang, Ning, Gottlieb, Rebecca K., Nogueira, Keith, Li, Xiaolong, Liang, Bradley, Kannard, Brian T.
• Primary Examiner(s): BERHANU, ETSUB D
• Application Number:
  US14/512,102
• Publication Number:
  US 20150031973A1
• Time in Patent Office: 1,180 Days
• Field of Search: None
• CPC Class Codes: A61B 5/1451 for interstitial fluid
• CPC Class Codes: A61B 5/14528 invasively
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61B 5/6849 in combination with a needle set
• CPC Class Codes: A61B 5/7242 using integration
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• 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: F04C 2270/0421 Controlled or regulated

Abstract

Subject matter disclosed herein relates to monitoring and/or controlling levels of an analyte in bodily fluid. In particular, estimation of a concentration of the analyte in a first physiological compartment based upon observations of a concentration of the analyte in a second physiological compartment may account for a latency in transporting the analyte between the first and second physiological compartments.

Claims

1. A method comprising:

estimating, using a controller of a glucose control system, a latency in transportation of an analyte between first and second physiological compartments, based, at least in part, upon at least one blood glucose reference sample;

compensating for the latency in estimating a concentration of the analyte in the first physiological compartment based, at least in part, on one or more observations of a concentration of the analyte in the second physiological compartment by;

accumulating over time a plurality of difference values between a sensor signal value and an offset value to provide an accumulation result;

combining a term with the accumulation result to provide a combined expression, wherein the term includes the estimated latency; and

determining the estimated concentration based, at least in part, on a computed rate of change in the combined expression; and

wherein the method further comprises generating, using the controller, a command to one or more infusion pumps based, at least in part, on the estimated concentration.

2. The method of claim 1, and further comprising applying a weight to the accumulation result according to the estimated latency.

3. The method of claim 1, wherein the analyte comprises glucose, the first physiological compartment comprises blood plasma, and the second physiological compartment comprises interstitial fluid.

4. The method of claim 1, wherein the sensor signal value comprises a measured current responsive to the concentration of the analyte in the second physiological compartment.

5. The method of claim 1, wherein the latency is based, at least in part, on a latency of a presence of glucose in a patient'"'"'s interstitial fluid to affect a blood glucose concentration in the patient.

6. The method of claim 5, wherein the latency is defined based, at least in part, on a time for 63% of glucose in the interstitial fluid to be absorbed by the patient'"'"'s blood.

7. An apparatus for use with at least one blood glucose reference sample and for use with one or more infusion pumps, the apparatus comprising:

a sensor configured to generate a signal responsive to a concentration of an analyte in a second physiological compartment; and

a processor configured to;

estimate a latency in transportation of the analyte between a first physiological compartment and the second physiological compartment, based, at least in part, upon the at least one blood glucose reference sample; and

compensate for the latency in estimating a concentration of the analyte in the first physiological compartment based, at least in part, on the signal responsive to the concentration of the analyte in the second physiological compartment by;

accumulating over time a plurality of difference values between the signal generated by the sensor and an offset value to provide an accumulation result;

combining a term with the accumulation result to provide a combined expression, wherein the term includes the estimated latency; and

determining the estimated concentration based, at least in part, on a computed rate of change in the combined expression,

wherein the processor is further configured to generate a command to the one or more infusion pumps based, at least in part, on the estimated concentration.

8. The apparatus of claim 7, wherein the signal generated by the sensor comprises a measured current responsive to the concentration of the analyte in the second physiological compartment.

9. The apparatus of claim 7, wherein the analyte comprises glucose, the first physiological compartment comprises blood plasma, and the second physiological compartment comprises interstitial fluid.

10. The apparatus of claim 7, wherein the processor is further configured to estimate the concentration of the analyte in the second physiological compartment by applying a weight to the accumulation result determined according to the estimated latency.

11. The apparatus of claim 7, wherein the latency is based, at least in part, on a latency of a presence of glucose in a patient'"'"'s interstitial fluid to affect a blood glucose concentration in the patient.

12. The apparatus of claim 11, wherein the latency is defined based, at least in part, on a time for 63% of glucose in the interstitial fluid to be absorbed by the patient'"'"'s blood.

13. An article for use with at least one blood glucose reference sample and for use with one or more infusion pumps, the article comprising:

a non-transitory storage medium having machine-readable instructions stored thereon which are executable by a special purpose computing apparatus to;

estimate a latency in transportation of an analyte between first and second physiological compartments, based, at least in part, upon the at least one blood glucose reference sample; and

compensate for the latency in estimating a concentration of the analyte in the first physiological compartment based, at least in part, on one or more measurements of a concentration of the analyte in the second physiological compartment by;

accumulating over time a plurality of difference values between a sensor signal value and an offset value to provide an accumulation result;

combining a term with the accumulation result to provide a combined expression, wherein the term includes the estimated latency; and

determining the estimated concentration based, at least in part, on a computed rate of change in the combined expression,

wherein the instructions are further executable by the special purpose computing apparatus to generate a command to the one or more infusion pumps based, at least in part, on the estimated concentration.

14. The article of claim 13, wherein the analyte comprises glucose, the first physiological compartment comprises blood plasma, and the second physiological compartment comprises interstitial fluid.

15. The article of claim 13, wherein the sensor signal value comprises a measured current responsive to the concentration of the analyte in the second physiological compartment.

16. The article of claim 13, wherein the latency is based, at least in part, on a latency of a presence of glucose in a patient'"'"'s interstitial fluid to affect a blood glucose concentration in the patient.