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

• US 20080033254A1
• Filed: 06/13/2007
• Published: 02/07/2008
• Est. Priority Date: 07/25/2003
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Shariati, Mohammad, Boock, Robert, Brister, Mark, Brauker, James, Li, Ying, Kamath, Apurv, Mahalingam, Aarthi
• Granted Patent: US 8,260,393 B2
• Time in Patent Office: Days
• US Class Current: 600/300
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• 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 5/14865 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 5/6848 Needles
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/725 using specific filters therefor, e.g. Kalman or adaptive filters A61B5/316 take precedence
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/726 using Wavelet transforms
• CPC Class Codes: A61B 5/743 Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots
• CPC Class Codes: A61B 5/7475 User input or interface means, e.g. keyboard, pointing device, joystick
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

Systems and methods for detecting noise episodes and processing analyte sensor data responsive thereto. In some embodiments, processing analyte sensor data includes filtering the sensor data to reduce or eliminate the effects of the noise episode on the signal.

Claims

1-38. -38. (canceled)

39. A method for analyzing data from a continuous analyte sensor, the method comprising:

receiving data from an analyte sensor;

detecting an occurrence of a signal artifact event based at least in part on an amplitude of a signal artifact, including detecting a start and an end of a signal artifact event; and

processing the received data, wherein the processing is based at least in part upon whether the signal artifact event occurs.

40. The method of claim 39, wherein detecting the occurrence of a signal artifact event comprises determining an amplitude of sensor data and determining an amplitude of a signal artifact.

41. The method of claim 40, wherein detecting the occurrence of a signal artifact event comprises detecting a start of a signal artifact event when an amplitude of a signal artifact meets a first predetermined condition.

42. The method of claim 41, wherein detecting the occurrence of a signal artifact event comprises detecting an end of a signal artifact event when an amplitude of a signal artifact meets a second predetermined condition.

43. The method of claim 42, wherein the first predetermined condition is different from the second predetermined condition.

44. The method of claim 39, wherein detecting an occurrence of a signal artifact event comprises comparing received data with filtered data to obtain at least one residual.

45. The method of claim 44, wherein the first predetermined condition is a residual amplitude that is at least about 5% of a sensor data amplitude, and wherein the second predetermined condition is a residual amplitude that is no more than about 5% of a sensor data amplitude.

46. The method of claim 39, wherein detecting an occurrence of a signal artifact event comprises determining a differential between a first residual at a first time point and a second residual at a second time point.

47. The method of claim 46, wherein the first predetermined condition is a differential amplitude that is at least about 5% of a sensor data amplitude, and wherein the second predetermined condition is a differential amplitude that is no more than about 5% of a sensor data amplitude.

48. The method of claim 39, wherein processing the received data comprises displaying a graphical representation of filtered data responsive to a determination of a start of a signal artifact event.

49. The method of claim 39, wherein the received data comprises unfiltered data, and wherein processing the received data comprises displaying a graphical representation of the unfiltered data responsive to a determination of an end of a signal artifact event.

50. The method of claim 39, wherein processing the received data comprises displaying a graphical representation of the unfiltered data except when a signal artifact event occurs.

51. A method for displaying data from a continuous analyte sensor, the method comprising:

receiving data from an analyte sensor, including at least one of unfiltered data and filtered data;

detecting an occurrence of a signal artifact event based at least in part on an amplitude of a signal artifact, including detecting a start and an end of a signal artifact event; and

displaying a graphical representation of filtered data responsive to a determination of a start of a signal artifact event.

52. The method of claim 51, wherein the received data comprises unfiltered data, and wherein processing the received data comprises displaying a graphical representation of the unfiltered data responsive to a determination of an end of a signal artifact event.

53. The method of claim 51, wherein processing the received data comprises displaying a graphical representation of the unfiltered data except when a signal artifact event occurs.

54. A device comprising a computer readable memory, the computer readable memory containing code for analyzing data from a continuous analyte sensor, wherein the code comprises:

instructions for receiving data from an analyte sensor, the data comprising at least one sensor data point;

instructions for detecting an occurrence of a signal artifact event based at least in part on an amplitude of a signal artifact; and

instructions for processing the received data, wherein the processing is based at least in part upon whether a signal artifact event has occurred.

55. The device of claim 54, wherein the instructions for detecting an occurrence of a signal artifact event comprise instructions for determining an amplitude of the sensor data and instructions for determining an amplitude of a signal artifact.

56. The device of claim 55, wherein the instructions for detecting an occurrence of a signal artifact event comprise instructions for detecting a start of a signal artifact event when an amplitude of a signal artifact meets a first predetermined condition.

57. The device of claim 56, wherein the instructions for detecting an occurrence of a signal artifact event comprise instructions for detecting an end of a signal artifact event when an amplitude of a signal artifact meets a second predetermined condition.

58. The device of claim 57, wherein the first predetermined condition is different from the second predetermined condition.

59. The device of claim 56, wherein the instructions for detecting an occurrence of a signal artifact event comprise instructions for comparing the received data with filtered data to obtain at least one residual.

60. The device of claim 58, wherein the first predetermined condition is a residual amplitude that is at least about 5% of a sensor data amplitude, and wherein the second predetermined condition is a residual amplitude that is no more than about 5% of a sensor data amplitude.

61. The device of claim 54, wherein the instructions for detecting an occurrence of a signal artifact event comprise instructions for determining a differential between a first residual at a first time point and a second residual at a second time point.

62. The device of claim 60, wherein the first predetermined condition is a differential amplitude that is at least about 5% of a sensor data amplitude, and wherein the second predetermined condition is a differential amplitude that is no more than about 5% of a sensor data amplitude.

63. A device comprising a computer readable memory, the computer readable memory containing code for displaying data from a continuous analyte sensor, wherein the code comprises:

instructions for receiving data from an analyte sensor, the data comprising at least one unfiltered or filtered sensor data point;

instructions for detecting an occurrence of a signal artifact event based at least in part on an amplitude of a signal artifact event; and

instructions for displaying a graphical representation of filtered data responsive to a determination of a start of a signal artifact event.

64. The device of claim 63, wherein the received data comprises an unfiltered signal, and wherein the instructions for processing the received data comprise instructions for displaying a graphical representation of the unfiltered data responsive to a determination of an end of a signal artifact event.

65. The device of claim 63, wherein the received data comprises an unfiltered signal, and wherein the instructions for processing the received data comprise instructions for displaying a graphical representation of the unfiltered data except when a signal artifact event has occurred.

66. A system configured to continuously measure an analyte in a host, the system comprising:

an analyte sensor configured to provide sensor data indicative of an analyte concentration in a host;

electronics operably connected to the sensor and comprising programming configured to detect a signal artifact event based at least in part on an amplitude of a signal artifact, including detecting a start and an end of a signal artifact event, wherein the electronics further comprise programming configured to process the sensor data, wherein the processing is based at least in part upon whether the signal artifact event is detected.

67. The system of claim 66, wherein the programming configured to detect a signal artifact event comprises programming configured to determine an amplitude of the sensor data and programming configured to determine an amplitude of a signal artifact.

68. The system of claim 67, wherein the programming configured to detect a signal artifact event comprises programming configured to detect a start of a signal artifact event when then an amplitude of a signal artifact meets a first predetermined condition.

69. The system of claim 68, wherein the programming configured to detect a signal artifact event comprises programming configured to detect an end of a signal artifact event when an amplitude of a signal artifact meets a second predetermined condition.

70. A system configured to continuously measure an analyte in a host, the system comprising:

an analyte sensor configured to provide sensor data indicative of an analyte concentration in a host;

electronics operably connected to the sensor and comprising programming configured to detect a signal artifact event based at least in part on an amplitude of a signal artifact, and wherein the programming configured to process the sensor data comprises programming configured to display a graphical representation of filtered data responsive to a determination of a start of a signal artifact event.

71. The system of claim 70, wherein the sensor data comprises unfiltered data, and wherein the programming configured to process the sensor data comprises programming configured to display a graphical representation of the unfiltered data responsive to a determination of an end of a signal artifact event.

72. The system of claim 70, wherein the sensor data comprises unfiltered data, and wherein the programming configured to process the sensor data comprises programming configured to display a graphical representation of the unfiltered data except when a signal artifact event has occurred.