SYSTEMS AND METHODS FOR REPLACING SIGNAL ARTIFACTS IN A GLUCOSE SENSOR DATA STREAM

• US 20160302731A1
• Filed: 06/29/2016
• Published: 10/20/2016
• Est. Priority Date: 08/22/2003
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Kamath, Arpurv U., Goode, Paul V., Brauker, James H., Thrower, James Patrick, Carr-Brendel, Victoria
• Granted Patent: US 9,649,069 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 2562/0271 Thermal or temperature sensors
• CPC Class Codes: A61B 2562/08 Sensors provided with means for identification, e.g. barcodes or memory chips
• CPC Class Codes: A61B 5/0004 characterised by the type of physiological signal transmitted
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• 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 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/726 using Wavelet transforms
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 5/7475 User input or interface means, e.g. keyboard, pointing device, joystick

Abstract

Systems and methods for minimizing or eliminating transient non-glucose related signal noise due to non-glucose rate limiting phenomenon such as ischemia, pH changes, temperatures changes, and the like. The system monitors a data stream from a glucose sensor and detects signal artifacts that have higher amplitude than electronic or diffusion-related system noise. The system replaces some or the entire data stream continually or intermittently including signal estimation methods that particularly address transient signal artifacts. The system is also capable of detecting the severity of the signal artifacts and selectively applying one or more signal estimation algorithm factors responsive to the severity of the signal artifacts, which includes selectively applying distinct sets of parameters to a signal estimation algorithm or selectively applying distinct signal estimation algorithms.

Claims

1-20. -20. (canceled)

21. A method for processing data from a glucose sensor, the method comprising:

applying a voltage to an electrochemical glucose sensor configured to measure glucose concentration in a host;

performing at least one process selected from a group consisting of switching the voltage applied to the glucose sensor, cycling the voltage applied to the glucose sensor, and pulsing the voltage applied to the glucose sensor;

measuring a signal response of the glucose sensor to the at least one process;

detecting a signal artifact based on the signal response;

generating an estimated glucose value based at least in part on the measuring and the detecting; and

displaying on a display the estimated glucose value.

22. The method of claim 21, further comprising providing the glucose sensor operably connected to electronic circuitry.

23. The method of claim 22, wherein the electronic circuitry is housed within an electronics system configured to be physically coupled to the glucose sensor.

24. The method of claim 23, further comprising physically coupling the glucose sensor to the electronics system, and, upon physically coupling the glucose sensor to the electronics system, causing the electronics system to automatically read information representative of characteristics about the glucose sensor.

25. The method of claim 24, wherein the characteristics include one or both of calibration information associated with the glucose sensor and identification information associated with the glucose sensor.

26. The method of claim 25, wherein the reading comprises transmitting the information using one or more of radio frequency, infrared, optical, acoustic, and magnetic induction.

27. The method of claim 26, further comprising monitoring, using the electronic circuitry, an output of a first electrode of the glucose sensor and an output signal of a second electrode of the glucose sensor.

28. The method of claim 27, wherein the detecting comprises identifying a drop in the output signal of the second electrode to about zero and associating the output drop with the glucose value.

29. The method of claim 27, wherein the monitored signals are representative of characteristics of a biological sample applied to the glucose sensor.

30. The method of claim 21, wherein the at least one process is the periodically switching the voltage applied to the glucose sensor.

31. The method of claim 21, wherein the at least one process is the cycling the voltage applied to the glucose sensor.

32. The method of claim 21, wherein the at least one process is the pulsing the voltage applied to the glucose sensor.

33. The method of claim 21, wherein the signal artifact is associated with a change in a pH value of a biological sample applied to the glucose sensor.

34. The method of claim 21, wherein the signal artifact is associated with a change in a temperature value of a biological sample applied to the glucose sensor.

35. The method of claim 21, wherein the signal artifact is associated with a change in available surface area of at least one of electrode of the glucose sensor.

36. A system for processing data from a glucose sensor, the system comprising:

an electrochemical glucose sensor configured to measure glucose concentration in a host, wherein a voltage is applied to the glucose sensor; and

wherein the system is configured to;

perform at least one process selected from a group consisting of switching the voltage applied to the glucose sensor, cycling the voltage applied to the glucose sensor, and pulsing the voltage applied to the glucose sensor;

measure a signal response of the glucose sensor to the at least one process;

detect a signal artifact based on the signal response;

generate an estimated glucose value based at least in part on the measurement and the detection; and

display on a display the estimated glucose value.

37. The system of claim 36, further comprises an electronic circuitry configured to be operably connected to the glucose sensor.

38. The system of claim 37, further comprises an electronics system that includes the electronic circuitry and configured to be physically coupled to the glucose sensor.

39. The system of claim 38, wherein the electronics system is configured to automatically read information representative of characteristics about the glucose sensor when the electronics system is physically coupled to the glucose sensor.

40. The system of claim 39, wherein the characteristics include one or both of calibration information associated with the glucose sensor and identification information associated with the glucose sensor.

41. The system of claim 40, wherein the electronics system is further configured to transmit the information using one or more of radio frequency, infrared, optical, acoustic, and magnetic induction.

42. The system of claim 41, wherein the electronic circuitry is further configured to monitor an output of a first electrode of the glucose sensor and an output signal of a second electrode of the glucose sensor.

43. The system of claim 42, wherein the detection comprises identification of a drop in the output signal of the second electrode to about zero, and association of the drop in the output with the glucose value.

44. The system of claim 42, wherein the monitored signals are representative of characteristics of a biological sample applied to the glucose sensor.

45. The system of claim 36, wherein the at least one process is the periodic switching of the voltage applied to the glucose sensor.

46. The system of claim 36, wherein the at least one process is the cycling of the voltage applied to the glucose sensor.

47. The system of claim 36, wherein the at least one process is the pulsing of the voltage applied to the glucose sensor.

48. The system of claim 36, wherein the signal artifact is associated with a change in a pH value of a biological sample applied to the glucose sensor.

49. The system of claim 36, wherein the signal artifact is associated with a change in a temperature value of a biological sample applied to the glucose sensor.

50. The system of claim 36, wherein the signal artifact is associated with a change in available surface area of at least one of electrode of the glucose sensor.