EP-3435867-B1 - SYSTEMS, DEVICES AND METHODS FOR ANALYTE MONITORING SYSTEM

EP3435867B1EP 3435867 B1EP3435867 B1EP 3435867B1EP-3435867-B1

Inventors

BURNETTE, Douglas, William
REICHERT, Stephen, Alan
HAMPAPURAM, HARI
KAMATH, APURV, ULLAS
LARVENZ, SHAWN
MANDAPAKA, Aditya
MCDANIEL, Zebediah
MILLER, TOM
WEDEKIND, Jeffrey, R.
ZENG, Yonghuang

Dates

Publication Date: 20260513
Application Date: 20170317

Claims (11)

A system comprising: an analyte sensor adapted to transmit analyte concentration data; a sensor electronics module adapted to receive analyte concentration data from the analyte sensor, wherein the sensor electronics module comprises a processor adapted to detect a change in the analyte concentration data, and wherein the processor is further adapted to compensate for a fluctuation exceeding a predetermined threshold in the analyte concentration data to accurately reflect analyte concentration in a host; wherein the sensor electronics module further comprises offset current circuitry adapted to generate a shifted signal by adding an offset current to a signal indicative of the analyte concentration data and a noise signal component associated with the fluctuation such that the signal indicative of the analyte concentration data and the noise signal component is shifted from below-zero levels to levels above zero, and such that the shifted signal includes the offset current in addition to the analyte concentration data and the noise signal component, wherein: the sensor electronics module is adapted to measure only positive signal values, the sensor electronics module is adapted to measure the shifted signal, and the addition of the offset current to shift the signal indicative of the analyte concentration data and the noise signal component to levels above the zero value ensures that any portion of the signal indicative of the analyte concentration data and the noise signal component that would have been clipped without the addition of the offset current can be captured.
The system of claim 1, further comprising at least one memory adapted to store information associated with the fluctuation in the analyte concentration data and a transmitter adapted to transmit the information associated with the fluctuation to at least one of a remote server and a display device adapted to display the information associated with the fluctuation or information derived therefrom.
The system of claims 1 or 2 comprising one or more environmental sensors to determine environmental conditions potentially causing the fluctuation in the analyte concentration data.
The system of claim 1, where the offset current circuitry is adapted to be triggered to add the offset current upon a determination that a zero-peak value associated with the noise signal component is greater than the signal indicative of the analyte concentration data.
They system of claim 1, wherein the offset current circuitry is adapted to be triggered to add the current upon a determination that a percentage of a zero-peak value associated with the noise signal component is greater than the signal indicative of the analyte concentration data.
The system of claim 1, wherein the offset current circuitry is adapted to add the offset current in accordance with one or more programmed offset currents.
The system of any preceding claim, wherein the processor is adapted to compensate for the fluctuation by averaging the measured shifted signal.
The system of claim 7, wherein the processor is adapted to subtract the added offset current after averaging the measured shifted signal.
The system of claim 1, further comprising a guard band having the same voltage differential as that existing between at least two electrodes of the analyte sensor to compensate for artifact-induced current flow across the voltage differential.
The system of claim 1, further comprising a processor adapted to directly adjust analyte concentration data by a predetermined adjustment amount based upon one or more factors causing the fluctuation.
A method of monitoring analyte concentration data using a system comprising an analyte sensor, and a sensor electronics module that comprises a processor and offset current circuitry, the method comprising: the analyte sensor transmitting analyte concentration data; the sensor electronics module receiving analyte concentration data from the analyte sensor, wherein the processor detects a change in the analyte concentration data and compensates for a fluctuation exceeding a predetermined threshold in the analyte concentration data to accurately reflect analyte concentration in a host, and the offset current circuitry generating a shifted signal by adding an offset current to a signal indicative of the analyte concentration data and a noise signal component associated with the fluctuation such that the signal indicative of the analyte concentration data and the noise signal component is shifted from below-zero levels to levels above zero, and such that the shifted signal includes the offset current in addition to the analyte concentration data and the noise signal component, wherein: the sensor electronics module measures only positive signal values, the sensor electronics module measures the shifted signal, and the addition of the offset current to shift the signal indicative of the analyte concentration data and the noise signal component to levels above the zero value ensures that any portion of the signal indicative of the analyte concentration data and the noise signal component that would have been clipped without the addition of the offset current can be captured.

Description

FIELD Various embodiments relate generally to continuous monitoring of analyte values received from an analyte sensor system, and in particular, to transmitter fault detection and responses to such faults. BACKGROUND Diabetes mellitus is a disorder in which the pancreas cannot create sufficient insulin (Type I or insulin dependent) and/or in which insulin is not effective (Type 2 or non-insulin dependent). In the diabetic state, the victim suffers from high blood sugar, which causes an array of physiological derangements (kidney failure, skin ulcers, or bleeding into the vitreous of the eye) associated with the deterioration of small blood vessels. A hypoglycemic reaction (low blood sugar) may be induced by an inadvertent overdose of insulin, or after a normal dose of insulin or glucose-lowering agent accompanied by extraordinary exercise or insufficient food intake. Conventionally, a diabetic person carries a self-monitoring blood glucose (SMBG) monitor, which typically requires uncomfortable finger pricking methods. Due to the lack of comfort and convenience, a diabetic person will normally only measure his or her glucose level two to four times per day. Unfortunately, these time intervals are spread so far apart that the diabetic person will likely find out too late, sometimes incurring dangerous side effects, of a hyperglycemic or hypoglycemic condition. In fact, it is not only unlikely that a diabetic person will take a timely SMBG value, but it is also unlikely that the diabetic will know if his or her blood glucose value is going up (higher) or down (lower) utilizing conventional monitoring systems and methods. Consequently, a variety of non-invasive, transdermal (e.g., transcutaneous) and/or implantable electrochemical sensors are being developed for continuously detecting and/or quantifying blood glucose values. These devices generally transmit raw or minimally processed data for subsequent analysis at a remote device, which can include a display. WO 2005/018443 A1 relates to microprocessors, devices, and methods useful for sweat and/or temperature detection that correlate more closely with changes in amperometric or charge signals related to analyte amount or concentration. The document also provides methods for the establishment of more accurate sweat and/or temperature thresholds and new methods of compensation, such as correcting for the effects of sweat and rapidly changing temperature on measured analyte values. The document relates to methods for reducing the number of skipped or unuseable readings provided by analyte monitoring devices during periods of sweating or changing temperatures. Further, the document further provides methods for improving the accuracy of reported readings of analyte amount or concentration. The document relates to passive collection reservoir/sensing devices used in combination with active collection reservoir/sensing devices for detection of sweat and/or temperature related parameters. WO 2013/184416 A2 relates to a diagnostic Electrochemical Impedance Spectroscopy (EIS) procedure that is applied to measure values of impedance-related parameters for one or more sensing electrodes. The parameters may include real impedance, imaginary impedance, impedance magnitude, and/or phase angle. The measured values of the impedance-related parameters are then used in performing sensor diagnostics, calculating a highly-reliable fused sensor glucose value based on signals from a plurality of redundant sensing electrodes, calibrating sensors, detecting interferents within close proximity of one or more sensing electrodes, and testing surface area characteristics of electroplated electrodes. Advantageously, impedance-related parameters can be defined that are substantially glucose-independent over specific ranges of frequencies. An Application Specific Integrated Circuit (ASIC) enables implementation of the EIS-based diagnostics, fusion algorithms, and other processes based on measurement of EIS-based parameters. US 2009/192751 A1 relates to systems and methods for processing sensor data. Systems and methods are provided for calibration of a continuous analyte sensor. Systems and methods are provided for classification of a level of noise on a sensor signal. Systems and methods are provided for determining a rate of change for analyte concentration based on a continuous sensor signal. In some embodiments, systems and methods for alerting or alarming a patient based on prediction of glucose concentration are provided. US 2015/0164371 A1 relates to electrochemical Impedance Spectroscopy (EIS) that is used in conjunction with continuous glucose monitors and continuous glucose monitoring (CGM) to enable in-vivo sensor calibration, gross (sensor) failure analysis, and intelligent sensor diagnostics and fault detection. An equivalent circuit model is defined, and circuit elements are used to characterize sensor behavior. US 2012/0262298 A1 relates to systems and methods for processing