Systems, devices and methods for analyte monitoring system

Abstract

To provide systems and methods for detecting changes or fluctuations in an analyte concentration signal that are abnormal, e.g., exceed a predetermined threshold, a current trend of analyte concentration measurements, etc.SOLUTION: Signals indicative of analyte concentration in a host may be received from an analyte sensor. The signals may be monitored, and a determination can be made as to whether there is a change in the signal. Upon detecting such a change, the change can be compensated such that a representation of the signal indicates the analyte concentration. Optionally, the cause of the detected changes or fluctuations can also be determined, and information regarding the detected changes or fluctuations can be recorded and analyzed for subsequent optimization of the systems and methods as well as for transmitting alerts, notifications, etc. to a user to take corrective action.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS All priority claims identified in the Application Data Sheet or any amendment thereto are hereby incorporated by reference under 37 CFR 1.57. This application claims the benefit of U.S. Provisional Application No. 62,315,539, filed March 30, 2016. The above applications are hereby incorporated by reference in their entirety and hereby expressly made a part of this specification.

[0002] Various embodiments relate generally to continuous monitoring of analyte values ​​received from an analyte sensor system, and more particularly to transmitter failure detection and response to such failures. [Background technology]

[0003] Diabetes mellitus is a disorder in which the pancreas cannot make enough insulin (type 1 or insulin-dependent) and / or insulin is not effective (type 2 or non-insulin-dependent). In the diabetic state, the victim suffers from high blood sugar, which leads to many physiological disturbances associated with the deterioration of small blood vessels (kidney failure, skin ulcers or bleeding into the vitreous of the eye). A hypoglycemic reaction (low blood sugar) can be induced by inadvertent overdosing of insulin or after regular intake of insulin or glucose-lowering drugs accompanied by excessive exercise or inadequate food intake.

[0004] Traditionally, people with diabetes carry self-monitoring blood glucose (SMBG) monitors, which generally require uncomfortable finger-cell prick techniques. Due to lack of comfort and convenience, people with diabetes usually measure their glucose levels only two to four times per day. Unfortunately, these time intervals are so far apart that it is often too late for a diabetic to realize that they are in a state of hyperglycemia or hypoglycemia, sometimes resulting in dangerous side effects. In fact, not only is it unlikely that a diabetic would ever take a timely SMBG reading, it is also unlikely that a diabetic would know if their blood glucose level is about to rise (higher) or fall (lower) utilizing conventional monitoring systems and methods.

[0005] Accordingly, a variety of non-invasive, transcutaneous (e.g., transdermal) and / or implantable electrochemical sensors have been developed to continuously detect and / or quantify blood glucose levels. These devices generally transmit raw or minimally processed data for subsequent analysis at a remote device, which may include a display. Summary of the Invention [Means for solving the problem]

[0006] The details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. Please note that the relative dimensions of the following figures may not be drawn to scale.

[0007] According to one embodiment, a computer-implemented method includes receiving a signal representative of an analyte concentration in a host from an analyte sensor and monitoring the signal, the computer-implemented method further includes determining whether there is a change in the signal and compensating for the change in the signal such that an indication of the signal reflects the analyte concentration in the host.

[0008] According to one embodiment, a method includes comparing a current clock time to a previously stored clock time after experiencing an interruption in operation of a sensor measurement circuit of an analyte sensor system, the method further includes synchronizing the current clock time with the previously stored clock time and incrementing a timestamp associated with the EGV data transfer based on the previously stored clock time.

[0009] According to one embodiment, a system includes an analyte sensor adapted to transmit analyte concentration data, the system further includes sensor measurement circuitry adapted to receive the analyte concentration data from the sensor and detect changes in the analyte concentration data, the sensor measurement circuitry compensating for fluctuations in the analyte concentration data that exceed a predetermined threshold.

[0010] According to one embodiment, the sensor electronics includes a processor and an offset circuit configured to apply an offset current to a received analyte concentration signal affected by noise upon the presence of noise determined by the processor.

[0011] According to one embodiment, a method includes receiving, at a processor of a system operating under power provided by the battery, one or more operating parameters associated with the battery. The method further includes monitoring a performance characteristic of the battery and determining whether the monitored performance characteristic deviates from a reference performance characteristic based on the one or more received operating parameters. The method still further includes wirelessly updating the one or more operating parameters upon determining that the monitored performance characteristic deviates from the reference performance characteristic.

[0012] According to one embodiment, a method includes receiving one or more operating parameters representative of a battery profile at a processor controlling the sensor measurement circuitry. The method further comprises receiving a boundary input based on the one or more operating parameters and determining whether the one or more received operating parameters fall within the received input boundary. The method further includes sending a notification to a user interface associated with the sensor measurement circuitry that the one or more operating parameters require an update upon determining that the one or more received operating parameters fall outside the received boundary input.

[0013] According to one embodiment, a method includes determining schedule information for an operation of an analyte sensor system and identifying payload information associated with the operation. The method further includes calculating an operating frequency of a charge pump according to the payload and the schedule information. The method further includes instructing the charge pump to operate at the calculated operating frequency during an occurrence of the operation.

[0014] Any of the features of an aspect specified herein is applicable to all other aspects and embodiments identified herein. Furthermore, any of the features of an aspect may be combined in any way, partially or fully, respectively, with other aspects described herein, for example, one, two, or more aspects may be combined in whole or in part. Furthermore, any of the features of an aspect may be optional with respect to other aspects. Any aspect of the method may be performed by a system or device of another aspect, and any aspect of the system may be configured to perform a method of another aspect.

[0015] The detailed description will be described with reference to the accompanying drawings, which are provided for illustrative purposes only and merely depict typical or example embodiments, which are provided to facilitate a reader's understanding of the systems and methods described herein, and are not to be considered limiting in breadth, scope, or applicability of the various embodiments. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram illustrating a particular embodiment of an exemplary continuous analyte sensor system in communication with at least one display device according to various technologies described in this disclosure. [Figure 2A] 2A is a block diagram of an example sensor electronics module of the example continuous analyte sensor system of FIG. [Figure 2B] FIG. 2B is a perspective view and a side view of the example sensor electronics module of FIG. 2A. [Figure 2C] FIG. 2C is a perspective view and a side view of the example sensor electronics module of FIG. 2A. [Diagram 3] FIG. 3 is a block diagram showing elements of an exemplary continuous analyte monitoring system and display device in communication with each other, according to various embodiments of the present disclosure. [Figure 4A] FIG. 4A is a flow chart illustrating example operations performed to compensate for variation in an analyte concentration signal according to various embodiments of the present disclosure. [Figure 4B] FIG. 4B is a flow chart illustrating example operations that may be performed to detect fluctuations in an analyte concentration signal, according to various embodiments of the present disclosure. [Figure 4C] FIG. 4C is a flow chart illustrating example operations that may be performed to determine a cause of variation in an analyte concentration signal, according to various embodiments of the present disclosure. [Figure 5A] FIG. 5A illustrates an analyte concentration signal and the addition of noise and offset currents according to various embodiments of the present disclosure. [Figure 5B] FIG. 5B illustrates an analyte concentration signal and the addition of noise and offset currents according to various embodiments of the present disclosure. [Figure 5C] FIG. 5C illustrates an analyte concentration signal and the addition of noise and offset currents according to various embodiments of the present disclosure. [Figure 5D]FIG. 5D illustrates an analyte concentration signal and the addition of noise and offset currents according to various embodiments of the present disclosure. [Figure 6] FIG. 6 is a flow chart illustrating example calibration operations performed according to various embodiments of the present disclosure. [Figure 7] FIG. 7 illustrates an implementation of a guard band according to various embodiments of the present disclosure. [Figure 8] FIG. 8 is a flow chart illustrating an example clock resynchronization operation performed by various embodiments of the present disclosure. [Figure 9A] FIG. 9A is a block diagram of battery-related aspects of the example sensor electronics module of FIG. 2A. [Figure 9B] FIG. 9B is a flow chart illustrating example operations performed to achieve battery configuration, according to various embodiments of the present disclosure. [Figure 9C] FIG. 9C is a flow chart illustrating example operations performed to utilize boundaries to determine a potential battery problem in which operating parameters have been entered incorrectly, according to various embodiments of the present disclosure. [Figure 9D] FIG. 9D is a circuit diagram showing the elements of an example charge pump. [Figure 9E] FIG. 9E illustrates an example output voltage with ripple associated with a charge pump, according to various embodiments of the present disclosure. [Figure 9F] FIG. 9F illustrates an example ripple-free output voltage associated with a charge pump, according to various embodiments of the present disclosure. [Figure 10] FIG. 10 is a block diagram of an example computing module that can be used to implement various features of the embodiments described in this disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The following description describes some exemplary embodiments of the disclosed technology in detail. Those skilled in the art will recognize that there are numerous variations and modifications of the disclosed embodiments that are encompassed by their scope. Therefore, the description of a specific exemplary embodiment should not be considered as limiting the scope of the present disclosure.

[0018] overview The above-described continuous detection or quantification of blood glucose levels can be accomplished using a continuous glucose monitor (CGM), which is one example of a continuous analyte sensor. In particular, the continuous analyte sensor measures the concentration of a given analyte (e.g., glucose) in the host, and a raw signal is generated by electronics (sometimes referred to as a sensor electronics module) associated with the continuous analyte sensor. The sensor electronics module can be physically connected to the continuous analyte sensor and includes electronics / sensor measurement circuitry configured to process a data stream associated with the analyte concentration measured by the continuous analyte sensor to generate sensor information including the raw signal / raw sensor data, converted sensor data, and / or any other sensor data derived therefrom, e.g., predictive or trend data. The sensor electronics module can be further configured to generate sensor information customized for each display device, such that different display devices can receive different sensor information for presentation to the host, host caregivers, etc. Furthermore, the sensor electronics module includes one or more communication modules, such as a wireless radio transmitter, for transmitting the sensor information to the display device. The display device may include one or more communication modules for transmitting sensor information or other data, such as fault or error information (described in more detail below), to a remote server or database.

[0019] In the above description, it is assumed that reliable and true raw signals are received by the sensor electronics module. However, in some cases, faults or errors may occur and the raw signals are no longer reliable and true. These faults or errors may be detectable by analysis of the signal, the clinical situation, or both. This allows identification to be performed to distinguish it from the actual measurement signal behavior and to the corresponding signal processing that may change according to the fault. Therefore, appropriate fault identification and corresponding processing techniques are used.

[0020] Faults or errors may occur in many ways, including whether they are related to the physiological activity of the host, e.g., metabolic reactions, and / or as the in vivo portion of the continuous analyte sensor becomes established in the host environment over time during use. They may be related to transient events within the patient's control, or to the external environment surrounding the continuous analyte sensor. Thus, various embodiments are directed to fault or error detection in a continuous analyte sensor system, and implementing one or more corrective / compensatory measures in response to the detected fault or error, such that a user of the analyte sensor system is provided with accurate analyte measurement data. For example, according to various embodiments, unusual or abnormal changes or fluctuations in a signal representative of an analyte concentration in a host may be detected. Once detected, the cause of the change in the signal may be determined, and the change in the signal may be accounted for such that the analyte concentration in the host is accurately represented.

[0021] The term "analyte" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art (and should not be limited to any special or customized meaning), and further refers to, but is not limited to, a substance or chemical component in a biological fluid (e.g., blood, interstitial fluid, cerebrospinal fluid, lymphatic fluid, or urine) that can be analyzed. Analytes can include naturally occurring substances, man-made substances, metabolites, and / or reaction products. In some embodiments, the analyte for measurement by the sensor head, device, and method is an analyte. However, other analytes are contemplated as well, including, but not limited to, the following: acarboxyprothrombin, acylcarnitine, adenine phosphoribosyl transferase, adenosine deaminase, albumin, alphafetoprotein, amino acid profiles (arginine (Krebs cycle), histidine / urocanic acid, homocysteine, phenylalanine / tyrosine, tryptophan), andrenostenedione, antipyrine, arabinitol enantiomers enantiomers, arginase, benzoylecgonine (cocaine), biotinidase, biopterin, C-reactive protein, carnitine, carnosinase, CD4, ceruloplasmin, chenodeoxycholic acid, chloroquine, cholesterol, cholinesterase, conjugated 1-β hydroxycholic acid, cortisol, creatine kinase, creatine kinase MM isoenzyme, cyclosporin AA), d-penicillamine, de-ethylchloroquine, dehydroepiandrosterone sulfate, DNA (acetylator polymorphism), alcohol dehydrogenase, alpha 1-antitrypsin, cystic fibrosis, Duchenne / Becker muscular dystrophy, analyte-6-phosphate dehydrogenase, hemoglobin A, hemoglobin S, hemoglobin C, hemoglobin D, hemoglobin E, hemoglobin F F), D-Punjab, beta-thalassemia, hepatitis B virus, HCMV, HIV-1, HTLV-1, Leber hereditary optic neuropathy, MCAD, RNA, PKU, Plasmodium vivax, sexual differentiation, 21-deoxycortisol, desbutylhalofantrine, dihydropteridine reductase, diptheria / tetanus antitoxin, erythrocyte arginase, erythrocyte protoporphyrin, esterase D, fatty acid / acylglycine acids / acylglycines, free β-human chorionic gonadotropinβ-human chorionic gonadotropin, free erythrocyte porphyrin, free thyroxine (FT4), free tri-iodothyronine (FT3), fumarylacetoacetase, galactose / gal-1-phosphate, galactose-1-phosphate uridyltransferase, gentamicin, analyte-6-phosphate dehydrogenase, glutathione, glutathione perioxidase, glycocholic acid, glycosylated hemoglobin hemoglobin, halofantrine, hemoglobin variants, hexosaminidase A, human erythrocyte carbonic anhydrase I, 17-alpha-hydroxyprogesterone, hypoxanthine phosphoribosyl transferase, immunoreactive trypsin, lactate, lead, lipoproteins ((a), B / A-1, 13), lysozyme, mefloquine, netilmicin, phenobarbitone, phenytoin, phytanic / pristanic acidacid, progesterone, prolactin, prolidase, purine nucleoside phosphorylase, quinine, reverse triiodothyronine (rT3), selenium, serum pancreatic lipase, sissomicin, somatomedin C, specific antibodies (adenovirus, anti-nuclear antibody, anti-zeta antibody, arbovirus, Aujeszky's disease virus, dengue virus, Dracunculus medinensis, Echinococcus granulosus, Entamoeba histolytica, enterovirus, Giardia duodenalisa, Helicobacter pylori, hepatitis B virus, herpes virus, HIV-1, IgE (atopic disease), influenza virus, Leishmania donovani, leptospira, measles / mumps / rubella, Mycobacterium leprae, Mycoplasma pneumomae, Myoglobin, Onchocerca volvulus, parainfluenza virus virus, Plasmodium falciparumfalciparum, poliovirus, Pseudomonas aeruginosa, respiratory syncytial virus, rickettsia (scrub typhus), Schistosoma mansoni, Toxoplasma gondii, Trepenoma pallidium, Trypanosoma cruzi / rangeli, vesicular stomatis virus, Wuchereria bancrofti, yellow fever virus), specific antigens (hepatitis B virus) virus, HIV-1), succinylacetone, sulfadoxine, theophylline, thyrotropin (TSH), thyroxine (T4), thyroxine-binding globulin, trace elements, transferrin, UDP-galactose-4-epimerase, urea, uroporphyrinogen I synthase, vitamin A, white blood cells, zinc protoporphyrinprotoporphyrin). Salts, sugars, proteins, fats, vitamins and hormones naturally present in blood or tissue fluids can also constitute analytes in certain embodiments. Analytes can be naturally present in biological fluids, such as metabolites, hormones, antigens, antibodies, etc. Alternatively, analytes can be introduced into the body, such as contrast agents for imaging, radioisotopes, chemical agents, fluorocarbon-based synthetic blood, or drugs or pharmaceutical compositions, including, but not limited to: Insulin, ethanol, cannabis (marijuana, tetrahydrocannabinol, hashish), inhalants (nitrous oxide, amyl nitrite, butyl nitrite, chlorohydrocarbons, hydrocarbons), cocaine (crack cocaine), cocaine), stimulants (amphetamines, methamphetamines, Ritalin, Cylert, Preludin, Didrex, PreState, Voranil, Sandrex, Plegine), depressants (barbiturates, methaqualone, tranquilizers such as Valium, Librium, Miltown, Serax, Equanil, Tranxene), hallucinogens (phencyclidine, lysergic acid, acid, mescaline, peyote, psilocybin), narcotics (heroin, codeine, morphine, opium, meperidine, Percocet, Percodan, Tussionex, Fentanyl, Darvon, Talwin, Lomotil), synthetic drugs (designerDrugs (fentanyl, meperidine, amphetamines, methamphetamines, and phencyclidine (e.g., analogs of Ecstasy), anabolic steroids, and nicotine. Metabolites of drugs and pharmaceutical compositions are also intended analytes. Analytes such as neurochemicals and other chemicals occurring within the body can also be analyzed, such as ascorbic acid, uric acid, dopamine, noradrenaline, 3-methoxytyramine (3MT), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 5-hydroxytryptamine (5HT), and 5-hydroxyindoleacetic acid (FHIAA).

[0022] In some embodiments, a system is provided for continuous measurement of a host analyte, the system including a continuous analyte sensor configured to continuously measure a concentration of a host analyte, and a sensor electronics module physically connected to the continuous analyte sensor for receiving the analyte concentration measurements and communicating them to a display device. In particular, the sensor electronics module includes electronics configured to process a data stream associated with the analyte concentration measured by the continuous analyte sensor and generate sensor information including raw sensor data, converted sensor data, and / or any other sensor data or data derived therefrom, e.g., predictive or trend data. The sensor electronics module can be further configured to generate sensor information customized for each display device, whereby different display devices can receive different sensor information for display to the host, host caregiver, etc. Furthermore, the sensor electronics module includes one or more communication modules, such as a wireless radio transmitter for transmitting the sensor information to the display device.

[0023] As used herein, the terms "raw data," "raw data stream," "raw data signal," "data signal," and "data stream" can refer to, but are not limited to, an analog or digital signal from a continuous analyte sensor related to a measured analyte. For example, the raw data stream provided by the continuous analyte sensor to the sensor electronics module may be digital data in "counts" converted by an A / D converter from an analog signal (e.g., voltage or current) representing the analyte concentration, which can include multiple time-spaced data points from a substantially continuous analyte sensor, each of which includes individual measurements taken at time intervals ranging from a fraction of a second to, for example, 1 minute, 2 minutes, 5 minutes, or more. In some embodiments, the raw data / counts may represent sensor information accumulated or averaged over a period of time (e.g., 5 minutes). Additionally, the term "counts" can refer to a unit of measure of a digital signal. For example, a raw data stream or raw data signal measured in counts can be related to a voltage (e.g., converted by an A / D converter), which is directly related to a current from a working electrode (described in more detail below).

[0024] In some embodiments, the sensor electronics module can be configured to search for and / or attempt to wirelessly communicate with a display device. In some embodiments, the search for and / or attempt to wirelessly communicate with a display device can occur in a predetermined and / or programmable order (e.g., gradually and / or in stages). It should be noted that the sensor electronics module is not necessarily tied to a single display device. Rather, the sensor electronics module can be configured to communicate with multiple different display devices, directly, systematically, simultaneously (e.g., via broadcast), periodically, periodically, randomly, on-demand, in response to a query, based on an alert or alarm, and / or the like.

[0025] Depending on the embodiment, the sensor electronics module receives sensor information from the continuous analyte sensor. This sensor information may be raw data that the display device receives and processes, for example, by one or more algorithms, to generate and / or display an estimated analyte value. In a continuous glucose monitoring context, the estimated analyte value may be estimated glucose value (EGV) data. For example, some display devices may include display instructions (software programming including instructions configured to display the sensor information and optionally query the sensor electronics module to obtain displayable sensor information) that include software configured to enable display of displayable sensor information thereon.

[0026] In other embodiments, processing of the raw data can be performed in the sensor electronics module. That is, the necessary algorithms, software and / or other processing functionality to convert the raw data to estimated analyte value data can occur in the sensor electronics module rather than in the display device. Converting the raw data in the sensor electronics module can avoid the possibility of inconsistent estimated analyte value data due to inconsistent calibrations, for example, between two or more display devices. Furthermore, implementing this functionality in the sensor electronics module can discourage third party display device / drug delivery device providers from tampering with or modifying the processing algorithms and software.

[0027] In some embodiments, a particular display device may be in direct wireless communication with the sensor electronics module, although intermediate network hardware, firmware and / or software may be included in the direct wireless communication. In some embodiments, a repeater (e.g., a Bluetooth® repeater) may be used to retransmit the transmitted sensor information to a location farther away than the adjacent range of the telemetry module of the sensor electronics module. In some embodiments, a receiver (e.g., a Bluetooth® receiver) may be used to retransmit the transmitted sensor information to a display device (e.g., a television screen), perhaps in a different format, such as a text message.

[0028] In some embodiments, one or more display devices are configured to query the sensor electronics module for sensor information, where the display device requests sensor information from the sensor electronics module in an "on-demand" manner, e.g., in response to a query. In some embodiments, the sensor electronics module is configured for periodic, systematic, periodic, non-periodic or aperiodic transmission of sensor information to one or more display devices (e.g., every 1, 2, 5, 10 or more minutes). In some embodiments, the sensor electronics module is configured to transmit data packages associated with an alert that has been triggered (e.g., triggered by one or more alert conditions). However, any combination of the above described states of data transfer can be performed by any combination of sensor electronics module and display device.

[0029] Exemplary Configurations of Continuous Analyte Monitoring Systems An analyte sensor, such as a glucose sensor, can be any device capable of measuring the concentration of an analyte. One exemplary embodiment is described below, which utilizes an implantable glucose sensor. However, it should be understood that the devices and methods described herein can be applied to any device capable of detecting a substance indicative of glucose concentration or the concentration or presence of another analyte and outputting an output signal indicative of the glucose concentration.

[0030] In some embodiments, the glucose sensor is a continuous device, such as a subcutaneous, transdermal, transcutaneous, non-invasive, intraocular, and / or intravascular (e.g., intravenous) device. In some embodiments, multiple intermittent blood samples can be analyzed. The glucose sensor can use any method of glucose measurement, including enzymatic, chemical, physical, electrochemical, optical, photochemical, fluorescence-based, spectrophotometric, spectroscopic (e.g., optical absorption spectroscopy, Raman spectroscopy, etc.), polarimetric, calorimetric, iontophoretic, radiometric, etc.

[0031] The glucose sensor can use any known detection method, including invasive, minimally invasive, and non-invasive sensing techniques, and provides a data stream representative of the concentration of an analyte in a host. The data stream, as described above, is generally a raw data signal used to provide a useful value of the analyte to a user, such as a patient or a medical professional (e.g., a physician) who may be using the sensor.

[0032] In one preferred embodiment, the analyte sensor is an implantable glucose sensor, such as those described in U.S. Patent Publication No. 6,001,067 and U.S. Patent Publication No. 2005 / 0027463. In another preferred embodiment, the analyte sensor is a transdermal glucose sensor, such as those described in U.S. Patent Publication No. 2006 / 0020187. In yet another embodiment, the sensor is configured to be implanted within the host's vasculature or body, such as those described in U.S. Patent Publication No. 2007 / 0027385, U.S. Patent Publication No. 2008 / 0119703, U.S. Patent Publication No. 2008 / 0108942, and U.S. Patent Publication No. 2007 / 0197890. In one alternative embodiment, the continuous glucose sensor comprises a transdermal sensor, such as those described in U.S. Patent Publication No. 6,565,509. In other alternative embodiments, the continuous glucose sensor includes a subcutaneous sensor, such as those described by U.S. Patent No. 6,579,690 or U.S. Patent No. 6,484,046. In other alternative embodiments, the continuous glucose sensor includes a refillable subcutaneous sensor, such as those described by U.S. Patent No. 6,512,939. In other alternative embodiments, the continuous glucose sensor includes an intravascular sensor, such as those described by U.S. Patent No. 6,477,395. In other alternative embodiments, the continuous glucose sensor includes an intravascular sensor, such as those described by U.S. Patent No. 6,424,847.

[0033] FIG. 1 is a diagram illustrating an example continuous analyte monitoring system 100 including an analyte sensor system 124 operatively connected to a host 120 and a plurality of display devices 134a-e in accordance with certain aspects of the present disclosure. It should be noted that the display device 134e may be a drug delivery device that may work in conjunction with the analyte sensor system 124 to deliver medicine to the host 120 instead of or in addition to being a display device. The analyte sensor system 124 may include a sensor electronics module 126 and a continuous analyte sensor 122 associated with the sensor electronics module 126. The sensor electronics module 126 may be in direct wireless communication with one or more of the plurality of display devices 134a-e via wireless communication signals. As described in more detail below, the display devices 134a-e may also communicate with the analyte sensor system 124 between and / or through each other. For ease of reference, the wireless communication signals from the analyte sensor system 124 to the display devices 134a-e may be referred to as "uplink" signals 128. For example, wireless communication signals from the display devices 134a-e to the analyte sensor system 124 may be referred to as “downlink” signals 130. Wireless communication signals between two or more display devices 134a-e may be referred to as “crosslink” signals 132. In addition, the wireless communication signals may include data transmitted by one or more display devices 134a-d to one or more remote servers 140 or network entities, such as cloud-based servers or databases, via “long-range” uplink signals 136 (e.g., cellular signals), and may receive long-range downlink signals 138 transmitted by the remote servers 140.

[0034] The sensor electronics module 126 includes sensor electronics configured to process the sensor information to generate transformed sensor information. In an embodiment, the sensor electronics module 126 includes electronic circuitry including prognostic algorithms associated with measuring and processing data from the continuous analyte sensor 122 and associated with processing and calibrating the continuous analyte sensor data. The sensor electronics module 126 can be integral (non-removably attached) or removably attached to the continuous analyte sensor 122, achieving a physical connection therebetween. The sensor electronics module 126 can include hardware, firmware, and / or software that enables the measurement of analyte levels. For example, the sensor electronics module 126 can include a potentiostat, a power supply for providing power to the continuous analyte sensor 122, other components useful for signal processing and data storage, and a telemetry module for transmitting data from itself to one or more display devices 134a-e. The electronics can be affixed to a printed circuit board (PCB), or the like, and can be in a variety of forms. For example, the electronic device may take the form of an integrated circuit (IC), such as an application specific integrated circuit (ASIC), a microcontroller and / or a processor. Examples of systems and methods for processing sensor analyte data are described in further detail herein and in U.S. Patent Nos. 7,310,544 and 6,931,327, and U.S. Patent Publication Nos. 2005 / 0043598, 2007 / 0032706, 2007 / 0016381, 2008 / 0033254, 2005 / 0203360, 2005 / 0154271, 2005 / 0192557, 2006 / 0222566, 2007 / 0203966, and 2007 / 0208245, all of which are incorporated herein by reference for all purposes.

[0035] The display devices 134a-e are configured to display drug delivery, communicate alarms, and / or base sensor information transmitted by the sensor electronics module 126 (e.g., in customized data packages transmitted to one or more display devices 134a-e based on their respective preferences). Each display device 134a-e can include a display, such as a touchscreen display, for presenting sensor information to a user (often the host 120 or a caregiver / healthcare professional) and / or receiving input from a user. In some embodiments, the display devices 134a-e can include other types of user interfaces, such as an audio user interface instead of or in addition to a touchscreen display, for conveying sensor information to a user of the display device 134a-e and / or receiving user input. In some embodiments, one, some, or all of the display devices 134a-e are configured to display or communicate sensor information as it is communicated from the sensor electronics module 126 (e.g., in data packages transmitted to the respective display devices 134a-e) without any additional prospective processing required for calibration and real-time display of the sensor information.

[0036] In the embodiment of FIG. 1, one of the plurality of display devices 134a-e may be a custom display device 134a specifically designed for showing a particular type of displayable sensor information (e.g., in some embodiments, numerical values ​​and arrows) associated with the analyte value received from the sensor electronics module 126. In some embodiments, one of the plurality of display devices 134a-e may be a portable device 134c, such as a mobile phone, palmtop computer, etc. based on the Android, iOS operating system, or other operating system, where the portable device 134c may be equipped with a relatively larger display and may be configured to show a graphical representation of the persistent sensor data (e.g., including current and historical data). Other display devices may include portable devices such as a tablet 134d, a smart watch 134b, a drug delivery device 134e, a blood glucose meter, and / or a desktop or laptop computer, etc.

[0037] As noted above, because the different display devices 134a-e provide different user interfaces, the contents of the data packages (e.g., the amount, format and / or type of data displayed, alarms, etc.) can be customized (e.g., programmed differently by manufacture and / or by an end user) for each particular display device and / or display device type. Thus, in the embodiment of FIG. 1, one or more of the display devices 134a-e can be in direct or indirect wireless communication with the sensor electronics module 126 to enable a number of different types and / or levels of display and / or functionality associated with the sensor information, as described in further detail elsewhere herein.

[0038] Continuous Analyte Sensors Typically, the continuous analyte sensor 122 may be an implantable analyte (e.g., glucose) sensor that utilizes amperometric electrochemical sensor technology to measure glucose concentration. The electrodes that comprise the continuous analyte sensor 122 may include a working electrode, a counter electrode, and a reference electrode. In an embodiment, a counter electrode is provided to balance the current generated by the species being measured at the working electrode. In the case of a glucose oxidase-based glucose sensor, the species being measured at the working electrode is H2O2. Glucose oxidase catalyzes the conversion of oxygen and glucose to hydrogen peroxide and gluconate according to the following reaction: Glucose + O2 Gluconate + H2O2

[0039] Since there is a proportional change in the product H2O2 for every glucose molecule metabolized, the change in H2O2 can be monitored to determine glucose concentration. The oxidation of H2O2 by the working electrode is balanced by the reduction of ambient oxygen, enzymatically generated H2O2, or other reducible species at the counter electrode. Further H2O2 produced from the glucose oxidase reaction reacts at the surface of the working electrode to produce two protons (2H+), two electrons (2e), and one oxygen molecule (O2).

[0040] In some alternative embodiments, additional electrodes may be included in the assembly, for example, in a three-electrode system (working, reference and counter electrodes) and an additional working electrode (e.g., an electrode that can be used to generate oxygen, configured as a basic subtraction electrode or configured to measure an additional analyte). U.S. Patent No. 7,081,195, U.S. Patent Publication No. 2005 / 0143635, and U.S. Patent Publication No. 2007 / 0027385, each of which is incorporated herein by reference, describe several systems and methods for implementing and using additional working, counter and reference electrodes. In some embodiments where more than one working electrode is provided, the second working electrode may be configured substantially similar to the first working electrode, but without the enzyme disposed thereon. In this manner, a baseline signal can be determined and subtracted from the first signal to generate a difference signal, i.e., a glucose-only signal that is substantially unaffected by fluctuations in the baseline or interfering species on the signal, as described, for example, in U.S. Patent Publication Nos. 2005 / 0143635, 2007 / 0027385, 2007 / 0213611, and 2008 / 0083617, which are incorporated herein by reference in their entireties.

[0041] Sensor Electronics Module 2A is a block diagram illustrating an embodiment of sensor electronics module 126 (FIG. 1). Sensor electronics module 126 may include an application specific integrated circuit (ASIC) 205, a user interface 222, a temperature sensor 252, a motion sensor 254, a body sensor 256, and a clock 258. ASIC 205 may also be coupled to a communication port 238 and a battery 234. Although FIG. 2A shows ASIC 205 including many of the electronic circuit components, ASIC 205 may be replaced with any suitable logic device, such as one or more of a field programmable gate array (FPGA), a microprocessor, analog circuitry, or other digital and / or analog circuitry. Additionally, the ASIC 205 may include one or more additional features of the sensor electronics module 126 described elsewhere herein, or one or more features illustrated in FIG. 2A as being part of the ASIC, such as the telemetry module 208, the potentiostat 210, the offset / calibration module 232, the data storage memory 220, and the clock 258, may be separate from the ASIC.

[0042] In this embodiment, potentiostat 210 (one example of an analog front end (AFE)) is coupled to continuous analyte sensor 122, for example, via data line 212, to receive sensor information acquired / measured by continuous analyte sensor 122. In some embodiments, potentiostat 210 provides a voltage to continuous analyte sensor 122 via data line 212 to bias continuous analyte sensor 122 to enable measurement of a current value representative of the analyte concentration in the host (also referred to as the analog portion). Potentiostat 210 can have one channel or multiple channels (and corresponding one or more data lines 212), for example, depending on the number of working electrodes. In some embodiments, potentiostat 210 includes a resistor (not shown) that converts current to voltage. In some embodiments, a current-to-frequency converter is provided that is configured to continuously integrate the measured current, for example, using a charge counting device. In some embodiments, an A / D converter digitizes the analog signal into "counts" (discussed above) for processing. Therefore, the counts in the resulting raw data stream can be directly related to the current measured by the potentiostat 210.

[0043] The processor 214 controls the operation of the sensor electronics module 126. In some embodiments, the processor 214 is formed as part of a custom chip such as an ASIC, however, computer systems other than an ASIC can be used to process data as described herein, for example, a microprocessor can be used for some or all of the sensor electronics module processing. The processor 214 typically provides a program memory 216, which provides semi-permanent storage of data, such as stored data, such as sensor identifiers (IDs), and programming for processing the data stream (e.g., filtering, calibration, fail-safe testing, etc.). The processor 214 can additionally be used for cache memory of the continuous analyte monitoring system 100, for example, to temporarily store recent sensor data. In some embodiments, the processor 214 includes memory storage components such as ROM, RAM, dynamic RAM, static RAM, non-static RAM, EEPROM, re-writable ROM, flash memory, etc. In one embodiment, the RAM 218 can be used for cache memory of the continuous analyte monitoring system 100, for example, to temporarily store recent sensor information.

[0044] In some embodiments, the processor 214 includes a digital filter, e.g., an infinite or finite impulse response (IIR or FIR) filter, configured to smooth the raw data stream from the AID converter. Typically, the digital filter is programmed to filter data sampled at predetermined time intervals (also referred to as a sample rate). In some embodiments, such as when the potentiostat 210 is configured to measure an analyte at discrete time intervals, these time intervals determine the sample rate of the digital filter. In some other embodiments, such as when the potentiostat 210 is configured to measure an analyte continuously, e.g., using a current-to-frequency converter, the processor 214 can be programmed to request digital values ​​from the integrator at predetermined time intervals, also referred to as an acquisition time. In these other embodiments, the values ​​obtained by the processor 214 can be averaged over the acquisition time, which should be given the continuity of the current measurements. Thus, the acquisition time determines the sample rate of the digital filter.

[0045] In one embodiment, the processor 214 can be further configured to generate data packages for transmission to one or more display devices. Furthermore, the processor 214 can generate data packets for transmission to these external sources, for example, via telemetry. As noted above, the data packages can be customizable for each display device 134a-e, for example, and can include any available data, such as customized sensor data and / or sensor information with converted sensor data, sensor / sensor electronics module ID codes, raw data, filtered data, calibrated data, rate of change information, trend information, error detection or correction, and / or the like.

[0046] The data storage memory 220 is operatively connected to the processor 214 and configured to store various sensor information. In some embodiments, the data storage memory stores persistent analyte sensor data, for example, for 1 day, 5 days, 9 days, 14 days, 15 days, 20 days, 30 days, or more. In some embodiments, the data storage memory 220 stores sensor information such as raw sensor data (one or more raw analyte concentration values), calibrated data, filtered data, converted sensor data, and / or any other displayable sensor information. Although separate data storage memory 220 and program memory 216 are shown in FIG. 2A, one skilled in the art will recognize various configurations including one or more memories that provide the necessary storage space to support the data processing and memory needs of the sensor electronics module 126.

[0047] The telemetry module 208 is operatively connected to the processor module 214 and provides hardware, firmware and / or software that enables wireless communication between the sensor electronics module 126 and one or more display devices 134a-e. Various wireless communication technologies that may be implemented by the telemetry module 208 include radio frequency (RF), infrared (IR), Bluetooth, Bluetooth Low Energy (BLE), spread spectrum communication, frequency hopping communication, ZigBee, IEEE 802.11 / 802.16, wireless (e.g., cellular) telecommunications, paging network communication, near field communication (NFC), radio frequency identification (RFID) magnetic induction, satellite data communication, GPRS, ANT, and / or the like. In one preferred embodiment, the telemetry module 208 includes a Bluetooth chip. In some embodiments, the Bluetooth technology is implemented by a combination of the telemetry module 208 and the processor 214.

[0048] The battery 234 is operatively connected to the processor 214 (and possibly other components of the sensor electronics module 126) and provides the necessary power to the sensor electronics module 126. In some embodiments, the battery is a lithium manganese dioxide battery, but any suitable size and power battery can be used (e.g., AAA, nickel cadmium, zinc carbon, alkaline, lithium, nickel metal hydride, lithium ion, zinc air, zinc mercury oxide, silver zinc, or hermetically sealed). In some embodiments, the battery 234 is rechargeable. In some embodiments, multiple batteries can be used to power the system. In some embodiments, the battery 234 can be a custom battery having one or more of a customized size, shape, and / or capacity optimized for the sensor electronics module 126, including a reduced capacity version if the sensor electronics module 126 has low energy requirements.

[0049] It should be noted that flexible electronics or flex circuit technology can be used to connect or incorporate the battery 234 to a printed circuit board assembly (PCBA) on which one or more components of the sensor electronics module 126 are placed. The use of flex circuit technology eliminates the need for rigid soldering of the battery 234 onto the PCBA as previously required, allowing for more freedom in the placement of the battery 234 thereon, which further allows for more flexibility in terms of the shape of the sensor electronics module 126 as well as reducing the size of the sensor electronics module 126. Furthermore, during conventional installation of the battery onto the PCBA, the battery is typically rigidly soldered and epoxied onto the PCBA. Because the battery may have different thermal properties than the surrounding circuitry, heating of the battery by the epoxy process can cause deflection of the PCBA and / or other components installed thereon. In contrast, the use of flex circuit technology allows the battery 234 to move during the epoxy curing process without affecting the surrounding circuitry.

[0050] The charger and / or regulator 236 can be configured to receive energy from an internal and / or external charger. In some embodiments, the battery regulator (or balancer) 236 regulates the charging process by bleeding off excess charge current to allow all cells or batteries 234 of the sensor electronics module 126 to be fully charged without overcharging other cells or batteries. In some embodiments, the battery (or batteries) 234 is configured to be charged via an inductive and / or wireless charging pad. Those skilled in the art will recognize various known methods of charging batteries that can be implemented in the systems described herein, including wired connections (cables / plugs) and wireless methods.

[0051] One or more communication ports 238 (also referred to as external connectors) are provided to allow communication with other devices, such as a PC communication (com) port to allow communication with systems separate or integrated with the sensor electronics module 126. The communication ports may include, for example, a serial (e.g., Universal Serial Bus or "USB") communication port to allow communication with another computer system (e.g., a PC, a smart phone, a personal digital assistant or "PDA", a server, or the like). In one embodiment, the sensor electronics module 126 is capable of transmitting to a separate computing device for retrospective analysis of historical data by the patient and / or physician.

[0052] Environmental sensors may also be utilized according to various embodiments. By way of example, a temperature sensor, such as temperature sensor 252, may be used to measure the temperature of the host 120 and / or the sensor electronics module 126. A motion sensor 254 may sense or determine changes in the host 120 in which the continuous analyte sensor 122 is implanted or operatively connected. A pressure sensor 256 may be used to detect pressure on the continuous analyte sensor 122 and / or pressure on adjacent tissue. It should be noted that more, e.g., other types of sensors or fewer sensors may be implemented in various embodiments to sense or detect changes associated with the host and / or the continuous analyte system that may cause one or more fluctuations or changes in a signal.

[0053] The clock 258 can control the rate at which the processor 214 executes instructions. As described below, the rate of the clock 258 can be set as desired. Additionally, the offset / calibration module 232 can be a circuit / logic component used to provide an offset current to shift the received signal at the potentiostat 210 when measuring current / counts, as well as to calibrate the potentiostat 210 for that additional offset current. In one embodiment, the offset current can also be adjusted by the offset / calibration module 232.

[0054] In conventional continuous analyte sensor systems, the epidermis-contacting portion of the sensor electronics is generally simplified to minimize the complexity and / or size of the electronics on the epidermis, and provides only raw, calibrated, and / or filtered data, for example, to a display device 134a-e that is configured to perform calibration and other algorithms required to display the sensor information. In contrast, the sensor electronics module 126 executes prognostic algorithms used to generate the converted sensor data and / or displayable sensor information, including, for example, algorithms to evaluate the clinical acceptability of the reference and / or sensor data, evaluate the calibration data for best calibration based on inclusion criteria, evaluate the quality of the calibration, compare estimated analyte values ​​to time-corresponding measured analyte values, analyze variability in estimated analyte values, evaluate stability of the sensors and / or sensor data, detect signal artifacts (noise), replace signal artifacts, determine rate of change and / or trends in the sensor data, perform dynamic and intelligent analyte value estimation, perform diagnostics on the sensors and / or sensor information, and set operational modes. , evaluating the data for deviations, and / or the like, as are described in more detail in U.S. Patent No. 7,310,544, U.S. Patent No. 6,931,327, U.S. Patent Publication No. 2005 / 0043598, U.S. Patent Publication No. 2007 / 0032706, U.S. Patent Publication No. 2007 / 0016381, U.S. Patent Publication No. 2008 / 0033254, U.S. Patent Publication No. 2005 / 0203360, U.S. Patent Publication No. 2005 / 0154271, U.S. Patent Publication No. 2005 / 0192557, U.S. Patent Publication No. 2006 / 0222566, U.S. Patent Publication No. 2007 / 0203966, and U.S. Patent Publication No. 2007 / 0208245, each of which is incorporated herein by reference in its entirety. Furthermore, the sensor electronics module 126 is configured to store the converted sensor data (eg, estimated analyte values, trend information) and communicate the sensor information to a number of different display devices 134a-e.In some embodiments, the display device is configured to show the sensor information as it is received from the sensor electronics module 126 without any additional sensor data processing.

[0055] The user interface 222 can include various interfaces, such as one or more buttons 224, a liquid crystal display (LCD) 226, a vibrator 228, an audio transducer (e.g., speaker) 230, a backlight (not shown), and / or the like. The components that comprise the user interface 222 can provide controls for interacting with a user (e.g., host). The one or more buttons 224 can enable, for example, toggle operations, menu selection, option selection, status selection, yes or no responses to on-screen questions, a "stop" function (e.g., for an alarm), an "acknowledge" function (e.g., for an alarm), a reset, and / or the like. The LCD 226 can provide, for example, visual data output to the user. The audio transducer 230 (e.g., speaker) can provide audible signals in response to activation of certain alerts, such as current and / or predicted hyperglycemic and hypoglycemic conditions.

[0056] 2B and 2C are perspective and side views of the analyte sensor system 124 including a mounting unit 240 and an attached sensor electronics module 126 in some embodiments, showing the functional position thereof, with the mounting unit and the sensor electronics module matingly engaged therein. In some embodiments, the mounting unit 240, also referred to as a housing or sensor pod, includes a base 242 adapted to be secured to the epidermis of a host. The base 242 can be formed from a variety of rigid or flexible materials, preferably including a low profile to minimize protrusion of the analyte sensor system 124 from the host 120 during use. In some embodiments, the base 242 is formed at least in part from a flexible material, which is believed to provide a number of advantages over conventional transcutaneous sensors, which can unfortunately suffer from motion-related artifacts associated with movement of the host 120 when the host 120 is using the analyte sensor system 124. The mounting unit 240 and / or sensor electronics module 126 can be placed over the sensor insertion site to protect the site and / or provide a minimal footprint (utilization of the host's epidermal surface area).

[0057] In some embodiments, a removable connection between the mounting unit 240 and the sensor electronics module 126 is provided, which can improve manufacturability, i.e., the relatively inexpensive mounting unit 240 can be discarded while the relatively more expensive sensor electronics module 126 can be reused when the continuous analyte sensor 122 is replaced after its useful life. In some preferred embodiments, the sensor electronics module 126 is configured with signal processing (programming) to, for example, filter, calibrate, and / or other algorithms that aid in calibrating and / or displaying sensor information as previously mentioned. However, an integrated (non-removable) sensor electronics module 126 can be configured according to other embodiments.

[0058] In some embodiments, the contacts 244 are mounted on or in a subassembly, hereinafter referred to as a contact subassembly 246, that is configured to fit into the base 242 of the mounting unit 240 and the hinge 248 that allows the contact subassembly 246 to pivot relative to the mounting unit 240 between a first position (for insertion) and a second position (for use). As used herein, the term "hinge" is a broad term and is used in its ordinary sense to refer to any variety of pivoting, articulation and / or hinge mechanisms (e.g., adhesive hinges, sliding joints, etc.), but is not limited thereto, and the term hinge does not necessarily refer to a fulcrum or fixed point at which articulation occurs. In some embodiments, the contacts 244 are formed from a conductive elastomeric material, such as a carbon black elastomer, by which the continuous analyte sensor 122 stretches.

[0059] In certain embodiments, the mounting unit 240 includes an adhesive pad 250 including a removable support layer disposed on the back surface of the mounting unit 240. In this manner, the mounting unit 240 is attached to the epidermis of the host 120 by removing the support layer and pressing the base portion 242 of the mounting unit 240 onto the epidermis of the host 120. Additionally or alternatively, the adhesive pad 240 can be placed over a portion or all of the analyte sensor system 124 after insertion of the continuous analyte sensor 122 is complete to ensure adhesion and, optionally, an air-tight or water-tight seal around the wound exit site (or insertion site) (not shown). A suitable adhesive pad can be selected or designed to stretch, stretch, conform, and / or ventilate the site (e.g., the epidermis of the host 120). The embodiments described with respect to Figures 2B and 2C are described in further detail with reference to U.S. Patent No. 7,310,544, which is incorporated herein by reference in its entirety.

[0060] Wireless communication 3 is a block diagram illustrating example components of the analyte sensor system 124 and at least one of the multiple display elements 134a, as well as communications therebetween. The analyte sensor system 124 may include an implantable persistent analyte sensor 312 (one embodiment of the persistent analyte sensor 122 of FIG. 1) coupled to a sensor measurement circuit 310 for processing and managing sensor data. The sensor measurement circuit 310 may be coupled to a processor 314 (part of the sensor electronics module 126 of FIG. 1). In some embodiments, the processor 314 may perform some or all of the functions of the sensor measurement circuit 310 for obtaining and processing sensor measurements from the implantable persistent sensor 312. The processor may further be coupled to a wireless unit or transceiver 316 (part of the sensor electronics module 126 of FIG. 1 of which the telemetry module 232 may be one embodiment) for transmitting sensor information to and receiving requests and commands from an external device, such as a display device 134a used to show or provide the sensor information to a user. As used herein, the terms "wireless unit" and "transceiver" are used interchangeably and generally refer to a device capable of wirelessly transmitting and receiving data. Such transmission and reception of data further includes the use of an antenna 324. It should be noted that multiple antennas may be utilized in the analyte sensor system 124. The analyte sensor system 124 may further include a memory 318 (also part of the sensor electronics module 126 of FIG. 1) for storing and tracking sensor information and a real-time clock (RTC) 320 (an exemplary embodiment of the clock 205 of FIG. 2A). In some embodiments, the analyte sensor system 124 further includes near field communication (NFC) capabilities. In some embodiments, an NFC tag 322 is implemented / integrated into the electronics of the analyte sensor system 124 or is incorporated into, for example, the housing or mounting unit 240. Although not explicitly illustrated, the NFC tag 322 may be included as part of the transceiver 316, making the transceiver 316 an "enhanced transceiver."

[0061] A wireless communication protocol can be used to transmit and receive data between the analyte sensor system 124 and the display device 134a. The wireless communication protocol used can be designed for use in a wireless sensor network optimized for periodic and small amounts of data transmission (which can be transmitted at a low rate if necessary) between multiple devices over a short distance (e.g., a personal area network (PAN)). For example, the wireless communication protocol can be optimized for periodic data transfers where the transceiver can transmit data for short intervals and then enter a low power mode for longer intervals. The wireless communication protocol can have low overhead requirements (e.g., by reducing header overhead) both for normal data transfers and for initially setting up the communication channel, reducing power consumption. In some embodiments, a burst broadcast scheme (e.g., one-way communication) can be used. This can eliminate the overhead required for acknowledgment signals and allow for periodic transmissions that consume little power.

[0062] The wireless communication protocol may be further configured to establish communication channels with multiple display devices, e.g., two or more display devices 134a-e, while implementing interference avoidance schemes. In some embodiments, the wireless communication protocol may utilize an adaptive isochronous network topology that defines various time slots and frequency bands for communication with some of the display devices 134a-e. The wireless communication protocol may thus modify transmission windows and frequencies in response to interference and to support communication with more than one of the display devices 134a-e. Thus, the wireless protocol may use a time and frequency division multiplexing (TDMA) based scheme. The wireless communication protocol may also use direct sequence spread spectrum (DSSS) and frequency hopping spread spectrum schemes. Various network topologies may be used to support short-range and / or low-power wireless communication, such as peer-to-peer, start, tree or mesh network topologies (e.g., WiFi, Bluetooth® and Bluetooth® Low Energy (BLE)). The wireless communication protocol may operate in various frequency bands, e.g., the open ISM band, such as 2.4 GHz. Furthermore, to reduce power usage, the wireless communication protocol can be optimally configured for data rate according to power consumption. Like the antenna 324 of the analyte sensor system 124, a corresponding antenna 340 is utilized in the display device 134a for transmitting / receiving data to / from the analyte sensor system 124. Also, one or more antennas in addition to the antenna 340 can be used to enable the various above-mentioned communication protocols to operate at their required frequencies / frequency ranges.

[0063] The display device 134a can be used to alert and provide sensor information to a user, such as the host 120, and can include a processor 330 for processing and managing the sensor information. The display device 134a can include a display 332, a memory 334, and a real-time clock 336 for displaying, storing, and tracking the sensor information, respectively. The display device 134a can further include a radio unit or transceiver 338 for receiving the sensor information and for transmitting requests, instructions, and data to the analyte sensor system 124. The transceiver 338 can further use a wireless communication protocol. The memory 334 can also be used to store an operating system and / or custom (e.g., proprietary) applications designed for wireless data communication between a transceiver, such as the transceiver 316, and the display device 134a, for example. The memory 334 can be a single memory device or multiple memory devices and can be a volatile or non-volatile memory for storing data and / or instructions for software programs and applications. The instructions may be executed by the processor 330 to control and manage the transceiver 338 .

[0064] In the case of the display device 134e, which may be a drug delivery device in addition to or instead of a display device, it should be understood that alerts and / or sensor information provided by the continuous analyte sensor 122 opposite the sensor electronics module 126 can be used to initiate and / or adjust delivery of medication to the host 120.

[0065] In some embodiments, when a standardized communication protocol is used, commercially available transceiver circuits may be available that incorporate processing circuitry to handle low level data communication functions such as data encoding, transmission frequency, and management of handshaking protocols. In these embodiments, the processors 314 and 330 do not have to manage these tasks, but rather provide the desired data values ​​for transmission and manage higher level functions such as increasing or decreasing power, the rate at which a message is transmitted, etc. Instructions and data values ​​for performing these high level functions may be provided to the transceiver circuits 316 and 338, respectively, via a data bus and transfer protocol established by the manufacturer of the transceiver circuits 316 and 338.

[0066] Components of the analyte sensor system 124 may require periodic replacement. For example, the implantable continuous analyte sensor 312, which may be attached to a sensor electronics module 126 that itself includes a sensor measurement circuit 310, a processor 314, a memory 318 and a transceiver 316, and a battery (not shown), may require periodic replacement (e.g., every 7-30 days). The sensor electronics module 126 may be configured to be powered on and operational for significantly longer (e.g., 3 months, 6 months or more) than the implantable continuous analyte sensor 312 before the battery requires replacement. Replacing these components may be difficult and require the assistance of trained personnel. Reducing the need to replace such components, including the battery if replaceable, greatly enhances the convenience of the analyte sensor system 124 to the host 120.

[0067] When the sensor electronics module 126 is used for the first time (or in some cases once the battery has been replaced and rebooted), it can connect to the implantable persistent analyte sensor 312. As described further below, there may be a way to initially establish communication between the display device 134a and the sensor electronics module 126 when it is used for the first time or rebooted (e.g., the battery has been replaced). Once the display device 134a and the sensor electronics module 126 have established communication, they may communicate periodically and / or persistently over the usable life of some implantable persistent analyte sensor 312, for example, until the battery or all of the sensor electronics module 126 needs to be replaced. Each time a persistent analyte sensor 312 is replaced, notification of the new persistent analyte sensor 312 may be sent / exchanged via the previously established communication between the sensor electronics module 126 and the display device 134a.

[0068] According to one embodiment, the analyte sensor system 124 collects and processes analyte measurements from the continuous analyte sensor 312 and periodically transmits sensor information representative of the analyte measurements to the display device 134a. Measurements are collected and transmitted throughout the usable life of the continuous analyte sensor 312 (e.g., ranging from 1 to 30 days or more). New measurements may need to be transmitted frequently enough to adequately monitor the analyte level. Rather than having the transmit and receive circuitry of each analyte sensor system 124 and display device 134a in continuous communication, the analyte sensor system 124 and display device 134a may periodically and periodically establish a communication channel between them. In this manner, the analyte sensor system 124 may wirelessly communicate with the display device 134a at predetermined time intervals. The length of the predetermined time interval can be selected to be long enough so that the analyte sensor system 124 does not consume too much power by transmitting data more frequently than necessary, yet is sufficient to provide substantially real-time sensor information (e.g., measured analyte values) to one or more display devices 134a-e for output (e.g., display) to a user. While the predetermined time interval is every five minutes in some embodiments, it is understood that this time interval can vary to be any desired length of time. It should be noted that other contemplated embodiments include irregular or non-periodic transmission of sensor information, for example, from the analyte sensor system 124 to one or more display devices 134a-e.

[0069] Fault Detection, Identification and Compensation As previously mentioned, various embodiments detect errors associated with measurements of the host analyte concentration and take corrective action so that the host analyte concentration is accurately represented. Inaccurate display of the analyte concentration value, particularly as presented to a user, may cause the user to take inappropriate action, impairing the performance of predictive or closed-loop algorithms and impairing the user's confidence in the continuous analyte system.

[0070] FIG. 4A is a flow chart illustrating operations performed according to example methods disclosed herein. At operation 400, a signal representative of a host analyte concentration is received from an analyte sensor. At operation 402, the signal is monitored, and at operation 403, it is determined whether there is a change in the signal. In other words, a fluctuation in the signal representative of the host analyte concentration is detected. At operation 410, a cause of the signal change or fluctuation is determined. At operation 420, the signal change is compensated for such that the host analyte concentration is accurately represented (i.e., in a display of a signal (e.g., a compensated signal) representative of the host analyte concentration free of noise). In another example, compensating for the fluctuation can include compensating for one or more types of fluctuation or noise, and the compensated signal can represent the analyte concentration free of one or more types of noise. It should be noted that the order of these steps can vary. For example, one or more of the sensors described above can detect an abnormal condition of the continuous analyte monitoring system 100 (e.g., a fluctuation exceeding a predetermined threshold), which can be associated with a subsequently detected fluctuation in the signal. Particular embodiments addressing fault detection and response are described in further detail below. It should be noted that operation 410 is represented by a dotted line indicating that it is an optional operation. That is, and as described in further detail below, fluctuations or noise can be compensated for without necessarily having to determine the source of the fluctuations or noise in advance. That is, particular embodiments can detect the fluctuations in the signal and compensate accordingly by adjusting the signal in some manner that produces a more accurate analyte concentration reading.

[0071] Fault Detection and Identification A measured analyte, e.g., glucose signal or data received by potentiostat 210, may be affected by a variety of factors. The effects of these various factors manifest themselves in anomalous fluctuations or changes, such as large spikes and / or increased noise, in the measured analyte signal or data. Various embodiments therefore detect and account for these anomalous fluctuations or changes. In some embodiments, the cause of the anomalous fluctuations or changes may also be identified and utilized as a basis for compensating for the anomalous fluctuations or changes and / or for collecting information, e.g., statistics, to optimize the operation of analyte sensor system 124.

[0072] For example, during an electrostatic discharge (ESD) event or due to normal physical activities / movements performed by a user, the measured glucose signal may undergo severe fluctuations or even be lost. In addition, the measured analyte signal may be affected due to issues with one or more elements of the sensor electronics module 126 (e.g., the transceiver 316). For example, the transceiver 316 may introduce noise into the measured analyte signal, thereby affecting the measured analyte signal captured by the working electrode during the measurement procedure. As another example, the sensor electronics module 126 may experience a power outage due to an unexpected depletion of the battery, which may result in an interruption of continuous analyte monitoring.

[0073] Regarding noise issues, the "internal" aspects of the analyte sensor system 124, such as circuitry such as the offset / calibration module 232, may by their very nature introduce noise into the measured analyte signal. That is, noise is a property of all electronic circuitry, and the introduction of additional circuitry such as the offset / calibration module 232 results in noise. For example, thermal noise may be introduced due to thermal motion of electrons, while shot noise may result due to random fluctuations in the current flowing through the circuitry. Still other noise may result from manufacturing defects or differing qualities (e.g., conductivity variations). Problems may also be caused by noise such as triboelectric noise and parasitic leakage, discussed below. In addition, "external" factors (external referring to factors originating / originating outside the analyte sensor system 124, such as the host 120), the movement or operation of the continuous analyte sensor 122 and / or the sensor electronics module 126 may also cause noise and / or otherwise inaccurate readings. In particular, if the sensor electronics module 126 is accidentally pressed or moved due to normal operation of the host 120, this can result in phase fluctuations (considered as noise) in the measured analyte signal / observed level.

[0074] FIG. 4B illustrates example operations (operations 400, 402, and 403 of FIG. 4A) performed to detect a fluctuation or change in a signal representative of a host analyte concentration. As previously described, in operation 402, the host signal (e.g., a measured glucose signal) is monitored. In operation 404, the presence of a fluctuation is based on a comparison (i.e., identification) of the host signal to reference information. As discussed above, the reference information may be some relevant predefined threshold, clinical status data, known glucose levels, etc. In operation 406, data regarding the fluctuation is captured. In some embodiments, capturing the fluctuation data may include reducing the sampling rate and / or overclocking the ASIC 205 (described in more detail below) to obtain more accurate fluctuation data.

[0075] Detection of abnormal variations or changes may be achieved by distinguishing between abnormal or unusual analyte concentration levels and "normal" or expected analyte concentration levels. The distinguishing may include determining whether the received signal or data matches or meets a predetermined criteria or performing a comparison between clinical context information corresponding to user data excluding the analyte concentration level / measurement. The distinguishing may include analyzing the signal using time series, frequency based or wavelet based techniques. The distinguishing may include raw signal analysis, residual signal analysis, pattern analysis and / or slow vs. fast sampling. The distinguishing may include projecting the received signal into a number of templates, each template corresponding to a failure mode. The distinguishing may include variation analysis or fuzzy logic analysis. The received clinical status data may be selected from the group consisting of age, anthropometric data, medications currently acting on the patient, temperature compared to a baseline, patient disorder history, patient activity level, patient exercise level, patient interaction level with the glucose monitor, pattern of glucose signal values, clinical glucose values ​​and derived values ​​thereof, range of patient glucose levels over time, duration of time that patient glucose levels are maintained within a range, patient glucose status, glycemic urgency index, time of day or blood pressure. The clinical status data may include time since implantation and the clinical status criteria may include range of time since implantation that subsidence and recovery failure are likely. The clinical status data may also include clinical glucose values ​​and data selected from the group consisting of age, anthropometric data, motion, exercise, clinical use of data or patient interaction with an analyte monitor. Exemplary systems and methods of identification that may be utilized in accordance with various embodiments herein are described in U.S. patent application Ser. No. 14 / 717,643.

[0076] 4C illustrates example operations that may be performed when determining the cause of the signal variation (operation 410 of FIG. 4A). Generally, an attempt is made to associate the detected variation with a detected condition or expression that may have caused the variation. Thus, in operation 412, one or more detectors, such as the temperature sensor 252, the motion sensor 254, etc. described above, may be interrogated to obtain information regarding at least one detected condition affecting the host and / or the continuous analyte sensor system that detected the signal variation.

[0077] For example, the pressure sensor 256 can detect pressure or compression using capacitive sensing. The pressure sensor 256 can include a metal foil embedded in the sensor electronics module 126 with an opposing metal plate on the bottom of the sensor electronics module 126 separated by a compressible membrane. In this manner, pressure on the sensor electronics module 126 compresses the membrane, thereby changing the capacitance detected by the opposing metal plate and foil.

[0078] The motion sensor 254 may be an accelerometer, such as a three-axis accelerometer, for detecting user activity / motion. The motion sensor 254 may also be used for compression detection, for example, sensing that the sensor electronics module 126 is in an inverted position. Analysis of this sensor data (as distinct from sensor information measured or determined by the continuous analyte sensor 122 related to analyte concentration) by the processor 214 may result in the processor 214 determining that the user is lying on the sensor electronics module 126. The processor 214 may then take steps (described in more detail below) to identify that the sensor electronics module 126 may give an erroneous reading of the measured analyte concentration because of a lack of oxygen, for example, because an area of ​​the user's tissue near the sensor electronics module 126 is being pressed or pinched. The motion sensor 254 may further include a three-axis compass that may be used in conjunction with the three-axis accelerometer to better determine the user's activity level.

[0079] Still other external factors, such as sensor drift, can result in signal variations. For example, sensor drift can occur in the continuous analyte sensor 122. Sensor drift can refer to an event in which sensitivity information (e.g., the relationship between measured current per unit time and glucose level) can be affected by changes in temperature. Because temperature can affect glucose metabolism, any change in temperature (whether caused by the user or the analyte sensor system 124) can alter the sensitivity of the continuous analyte sensor 122, which can result in an inaccurate glucose measurement or level being presented to the user.

[0080] The temperature fluctuations may be due to external factors (e.g., changes in the user's body temperature) and / or internal factors (e.g., changes in the temperature of the circuitry that includes the sensor electronics module 126 or the continuous analyte sensor 122 itself). Thus, the temperature sensor 252 may be used to detect whether a fault or fluctuation may be caused by sensor drift. In particular, predetermined knowledge of a particular amount of drift associated with a particular temperature or temperature range may be used as a basis for compensating for any fluctuations or noise (described in more detail below) upon detecting the presence or occurrence of that particular temperature or temperature range.

[0081] It should be noted that the temperature sensor 252 can measure the skin temperature of the host, tissue adjacent to the implantation site of the continuous analyte sensor 122, etc. Thus, the temperature sensor 252 can be implemented in a variety of ways and / or can refer to an array of sensors including, but not limited to, an infrared temperature sensor located underneath the sensor electronics module 126 (close to the host's epidermis) so as to be visible through the mounting unit 240, a thermocouple temperature sensor protruding from the bottom of the sensor electronics module 126 and allowing contact with the host's epidermis through the mounting unit 240, a semiconductor temperature sensor embedded in the mounting unit 240 allowing direct epidermal contact, etc. It should be further noted that any sensor itself or the data storage memory 220 can store sensor manufacturing and calibration information (whether it is the temperature sensor 252 or another sensor, such as, for example, the motion sensor 254, the pressure sensor 256, etc.). Such stored sensor manufacturing and calibration information can include, but is not limited to, factory calibration settings or information, sensor identification information, etc. Such information may be stored and used for comparison purposes or as a baseline or threshold upon which the sensor electronics module 126 may base, for example, sensor and / or temperature drift determinations, noise, disturbance, fluctuation determinations, etc. Furthermore, the temperature sensor 252 may be implemented as a subcutaneous temperature sensor for sensing the temperature proximate or at the tip of the continuous analyte sensor 122. The various temperature sensors described above may also be utilized to measure the temperature of other sensors and may be used in an effort to correlate and compensate for fluctuations and causes.

[0082] Problems such as spikes and / or noise in measured glucose values ​​can result from liquid ingress. That is, liquids such as water can inadvertently seep into the sensor electronics module 126, causing fluctuations and / or noise in the glucose signal. In particular, water leakage in / through / at the sensor electronics module 126 or the mounting unit 240 can, for example, temporarily cause the measured glucose signal to spike above a "normal" level, enough to introduce noise. For example, water infiltration can result in a large spike in the measured glucose value followed by severe noise. After drying, severe noise can reappear before a gradual normalization of the measured glucose value. It should be noted that a humidity sensor (not shown) capable of detecting moisture can be implemented within the sensor electronics module 126 and / or as part of the mounting unit 240 to detect the presence of liquid. It should be noted that the various sensors illustrated and described herein, such as the pressure sensor 256, the motion sensor 254, etc., can be implemented as separate sensors or as sensors with combined functionality.

[0083] At operation 414, the variation is associated with at least one detected condition based on at least one characteristic of the variation. For example, the time at which the variation occurs, as an example, can be used to associate the occurrence of some condition captured by the sensor with the variation. In addition, the type and / or amount of the variation (e.g., internal noise or external noise) or the frequency of the variation (e.g., large spikes due to sudden pushes or ESD) can provide a basis for the association. At operation 416, data representative of the variation is recorded. For example, data regarding when and how the variation was introduced can be captured and recorded and used to provide further understanding of the variation in glucose values ​​(or used later to compensate or better adjust for future variations). Recording can occur locally and / or may require wireless transfer to a remote server for use / analysis of the data by a technician, physician, caregiver, etc. Once a fluctuation or change is detected, the disturbance can be categorized based on the received signal, the clinical context information, or both, where categorizing the disturbance includes categorizing the disturbance as a sensor environment disturbance or as a system error / artifact disturbance, and / or subcategorizing the disturbance as, for example, a compression disturbance or an early wound response. In other words, the cause of the fluctuation or change can be determined. For example, the fluctuation occurs by determining the presence of some signal criteria measured by the processor 214 and follows some pattern that is not usually associated with a physiological change, e.g., a rate of change (a sudden drop) in the raw sensor signal. The processor 214 can have knowledge regarding the time of day and regarding sensor information indicating that the user may be asleep (e.g., from the motion sensor 254 sensing a general lack of motion over a period of time) and that the user may have rolled over the continuous analyte sensor 122 (e.g., from the pressure sensor 256).Upon receiving such sensor data and comparing the sensor data with that information known to the processor 214 (i.e., the time of day), the processor 214 can determine that the user was asleep and rolled over the continuous analyte sensor 122, and that this is what caused the sudden drop in glucose reading (i.e., due to a lack of oxygen at the implantation site of the continuous analyte sensor 122).

[0084] Upon determining the cause of the failure, the processor 214 can take one or more actions to notify the user of the cause and, for example, suggest a corrective response. For example, if a sudden drop in glucose reading occurs and is determined to be the result of the user rolling over the continuous analyte sensor 122 (as described above), the processor 214 can instruct the user interface 222 and / or one or more of the display devices 134a-e to activate an alert or notification. For example, the user interface 222 can activate the vibrator motor 228 to alert the user and / or simultaneously display a notification on the LCD 226 instructing the user to reposition. In this manner, the user can take corrective action. The processor 214 can further instruct the user interface and / or one or more of the display devices 134a-e to inform the user that they should wait for more accurate results before taking any corrective action. Furthermore, information can be gathered about the occurrence of a fault and / or the cause of such a fault so that the processor 214 can better predict or estimate a better or more optimal time to transmit EGV data to one or more display devices 134a-e. For example, the processor 214 can cause a delay before transmitting the current EGV data if the processor 214 determines that the user has rolled over the continuous analyte sensor 122.

[0085] Once a disturbance, e.g., an abnormal or anomalous fluctuation or change in the signal, is detected and the cause of the disturbance is determined, the fluctuation or change in the signal is accounted for to provide an accurate representation of the host analyte concentration.

[0086] compensation Noise Compensation As previously discussed, noise, whether from circuitry within the analyte sensor system 124 or from external sources, can affect the analyte concentration signal captured by the working electrode. Thus, various embodiments may utilize an offset to compensate for such noise.

[0087] The continuous analyte sensor 122 is typically configured to operate at very low currents (e.g., in the picoamp (pA) range). FIG. 5A is an example graph showing a glucose signal 500 (current I in pA) over time t. FIG. 5A shows an example analyte measurement at approximately 100 pA. The noise level caused by internal noise sources (e.g., the circuit and / or the triboelectric effect described above) can far exceed that of the glucose signal level and can even cause the glucose signal level to fall below zero. An example of this is illustrated in FIG. 5B, where the noise signal 502 oscillates between 200 pA and −200 pA. If the sensor electronics module 126 is configured to measure only positive signal values, any noise that causes the glucose signal level to fall below zero will not be observed and will not be compensated for.

[0088] In the embodiment illustrated in FIG. 5C, a measurement signal including an actual glucose signal (i.e., glucose signal 500 and noise signal 502) is shown (i.e., measurement signal=glucose signal+noise). Recalling the example glucose signal illustrated in FIG. 5A (glucose signal=100 pA) and the example noise signal illustrated in FIG. 5B (noise oscillating between 200 pA and −200 pA), the resulting signal 504 in FIG. 5C oscillates between 300 pA and −100 pA without any offset. The portion of the measurement signal between 0 pA and −100 pA is not observed or accounted for. Thus, a value obtained from averaging (e.g., filtering) a measurement signal (e.g., signal 504) may include errors. For example, the average value resulting from averaging (e.g., the negative portion is not accounted for therein) the measurement signal 504 may result in an erroneously higher (i.e., positively biased) value.

[0089] Thus, in some embodiments, an offset current is introduced so that in addition to the actual glucose signal and any noise, the measurement signal also contains an offset (i.e., measurement signal = glucose signal + noise + offset). Figure 5D illustrates an example of such a measurement signal 506, where adding an offset of, for example, 100 pA increases the measurement signal so that all noise can be captured (the measurement signal never drops below zero) and compensated for. In such an embodiment, the measurement signal is averaged to obtain an accurate value. In some embodiments, the offset value can be subtracted after averaging the measurement signal.

[0090] It should be noted that some embodiments utilize a filter mechanism in which the measurement signal is averaged. In some cases, as noise increases, the average value of the measurement signal may bias in the positive direction. Recalling the above example illustrated in FIG. 5C, any negative portion of the measurement signal is not accounted for. As indicated above, this causes averaging errors. Therefore, various embodiments may also compensate for the averaging errors by utilizing an offset circuit.

[0091] Triboelectric noise was mentioned earlier. The triboelectric effect is an event that occurs due to friction between materials with different electrical charges. In the case of triboelectric noise, the averaged sum can be zero. For example, by capturing all noise present in the measurement signal, triboelectric noise can be effectively cancelled. However, in some embodiments, the continuous analyte sensor 122 cannot capture the negative part of the measurement signal, thus leading to averaging errors. Since the measurement signal (current) is proportional to the glucose concentration, an incorrectly high reading can be problematic (especially if the user is hypoglycemic).

[0092] Implementing an offset current can be accomplished by using a programmable offset current (e.g., 0 nA, 10 nA, 20 nA, 40 nA). It should be noted that the offset current can be in the pico- to nano-amp order range, and the offset currents mentioned above are merely examples. Such a programmable offset current can be realized during the manufacturing stage by the offset / calibration module 232. Alternatively, based on noise measurements, for example, each time a new continuous analyte sensor 122 is used, or during real-time use of the analyte sensor system 126, an appropriate offset current can be selected / utilized by the offset / calibration module 232. It should be noted that in scenarios where the measurement signal, including the true glucose signal and the noise signal, oscillates between only positive values, an offset current does not need to be utilized. Thus, the above-mentioned option has an offset current of 0 nA. In one embodiment, the processor 214 can monitor the glucose and noise signal values ​​and predetermined thresholds for such signals, and the selection / utilization of the offset current occurs as described herein. In some embodiments, the processor 214 may monitor the measurement signal including the glucose and noise signals if the zero-peak value or a percentage of the zero-peak value (e.g., half of the zero-peak value) of the noise signal exceeds that of the glucose signal or glucose value. The processor 214 may monitor the measurement signal continuously, periodically according to some predetermined schedule, aperiodically, or by sampling the signal received by the potentiostat 210 from the continuous analyte sensor 122. Once the processor 214 analyzes the measurement signal and determines that the zero-peak value or a percentage of the zero-peak value of the noise signal exceeds that of the glucose signal or glucose value, the processor 214 instructs the offset / calibration module 232 to inject an appropriate offset current.

[0093] The offset current also shifts the glucose and noise signals (measurement signals) up above zero and can capture any portions of the measurement signals that would otherwise be truncated. The processor 214 or offset / calibration module 232 can then rely on appropriate software / algorithms to subtract the known offset from the measurement signals, and in some cases, the averaged measurement signals, to read out the true glucose signal level. In some embodiments, the processor 214 and / or offset / calibration module 232 can operate simply to add an offset current, while in other embodiments, the processor 214 and / or offset / calibration module 232 can be configured to both add an offset current and subtract any added offset current.

[0094] As mentioned above, electrical circuits inherently generate noise. Thus, the same is true for the offset / calibration module 232. That is, the use of the offset circuit of the offset / calibration module 232 adds another variable (offset current) to the measurement signal, which, if not compensated for, can result in, and of itself, the addition of further error / noise. In other words, the true offset value cannot be obtained from the offset circuit. Thus, some embodiments also compensate for the noise generated in the offset circuit.

[0095] In particular, the processor 214 relies on appropriate software / algorithms to "shut off" or inhibit operation of the working electrode. The potentiostat 210 (and / or the processor 214) can then be adjusted for a "true zero" (e.g., offset current). In some cases, the processor 214 and / or the calibration module 232 may provide a calibration procedure for determining the offset current. That is, the software / algorithm can disable the external connection (data line 212) to the working electrode so that it can calculate an offset current from the offset / calibration module 232 instead of the normally calculated current flow between the working and counter electrodes. It should be noted that the calibration can be initiated based on some predefined schedule after installation of a new continuous analyte sensor 122, etc. Another trigger for initiating the calibration can be a trend determined by the processor 214 indicating that more and more offset current is occurring over a certain threshold time. This can be determined by monitoring the number of times the offset / calibration module 232 is activated and / or recording the amount of offset current used in the data storage memory 220.

[0096] 6 illustrates example operations that may be performed to accomplish an offset current compensation calibration in accordance with various embodiments. In operation 600, operation of the working electrode is inhibited. As discussed above, the working electrode is essentially blocked or disabled so that a true zero current can be calculated from the offset / calibration module 232 in place of the normally calculated current flow between the working and counter electrodes. For example, ignoring noise, I(total, i.e., measured value) = I(working electrode, WE) + I(offset)

[0097] Once the working electrode is turned off, analyte measurements are no longer being taken and an offset value can be determined in operation 602. I(measurement) = I(offset)

[0098] Once calibrated, the working electrode can be enabled in operation 604. Once the average analyte concentration level has been calculated, the offset value can be subtracted from the averaged result as described above in operation 606 to read out the glucose signal level. That is, the processor 214 or offset / calibration module 232 can then rely on appropriate software / algorithms to subtract the known offset from the averaged measured signal to read out the actual glucose signal level.

[0099] It should be noted that calibration can be performed in a variety of ways. For example, calibration can be performed based on some predefined schedule. For example, if it is known that the applied current offset changes, but the variation of the current offset is to a particular amount over a particular time, calibration may be scheduled accordingly. Alternatively, a one-time calibration can be performed (e.g., during manufacturing). Alternatively, a real-time calibration can be performed. For example, if the offset current changes frequently, the processor 214 or the offset / calibration module 232 can perform additional calibration procedures.

[0100] In particular, in response to noise and / or spikes associated with a fluid ingress problem, a user-initiated calibration can be performed as a compensatory measure. When there is a large rise in the estimated glucose value (EGV) data after severe noise (which may result after water ingress, as described above), the user's confidence in the EGV should be considered low. Thus, the analyte sensor system 124 can prompt and / or alert the user to perform a calibration of the continuous analyte sensor 122, or can question the user regarding a current activity, for example, or confirm that there has been an accidental water leak occurrence. Additionally, the processor 214 can instruct the user interface 222 to prompt the user to input the blood glucose value obtained respectively. If the blood glucose value is very different from the EGV, the processor 214 can alert or warn the user of a potential failure and instruct the user interface 222 to wait a certain predetermined time during which a time calibration can be performed to ensure that the continuous analyte sensor 122 is in proper operating condition. It should be noted that in some embodiments, the alerts and / or questions discussed above may be transmitted to and / or provided by one or more of the display devices 134a-e. Accordingly, one or more of the display devices 134a-3 may have its own user interface, including one or more input mechanisms, displays, notification mechanisms, etc.

[0101] Another problem that can arise from the introduction of offset current is sensor (temperature) drift. As mentioned above, sensor drift can be experienced in the continuous analyte sensor 122 due to changes in temperature. Because temperature can affect glucose metabolism, any changes in temperature (whether caused by the user or the analyte sensor system 124) can alter the sensitivity of the continuous analyte sensor 122, which can result in inaccurate glucose measurements or levels being presented to the user. Therefore, a temperature calibration can be performed to compensate for temperature drift.

[0102] In this example, the introduction of additional (offset) currents may cause temperature drift to occur within the sensor electronics module 126, and the resulting temperature difference may adversely affect the offset value. Alternatively, the offset current may suffer from temperature drift that may occur due to temperature variations within the circuitry of the sensor electronics module 126 itself. To compensate, the offset / calibration module 232 may be used during manufacturing (e.g., factory calibration) to address variations in the offset value caused by the temperature of the sensor electronics module. That is, the temperature sensor 252 may be used to capture temperature variations, and upon detecting a predefined temperature variation threshold (e.g., as indicated in a look-up table, pre-programmed into an appropriate algorithm, etc.), the processor 214 may instruct the offset / calibration module 232 to perform a calibration procedure. In some embodiments, it may be the processor 214 that performs the calibration procedures, whether they are calibration procedures initiated due to offset current issues, temperature drift, etc. It should be noted that calibration as disclosed herein may refer to various types or methods of calibration. In some embodiments, calibration can refer to a one-point calibration process, a three-point calibration process, etc. For example, a three-point calibration can be performed for offsets that include different value ranges, while a one-point calibration can be performed for addressing temperature drift, for example, when the sensor electronics module 126 has a single operating temperature / range.

[0103] According to another type of compensation, the processor 214 can continuously detect the temperature (of the host, one or more components of the continuous analyte sensor system 124, etc.) and compensate for changes in the glucose information that may occur due to temperature fluctuations by referencing a lookup table or based on a real-time algorithm that links glucose levels and / or current values ​​to temperature. Alternatively, the processor 214 can refer to the temperature sensor 252 whenever there is a fluctuation in the measured glucose reading and compensate for the change according to a given fluctuation in temperature. That is, rather than (or in addition to) compensating for noise as a result of sensor drift, the processor 214 can "directly" compensate the measured analyte level based on the temperature measurement. For example, upon receiving information from the temperature sensor 252 that a particular temperature has been detected, the processor 214 can adjust the received glucose value in a manner commensurate with the sensed temperature until the temperature sensor 252 senses that the temperature has returned to a default value or range. In one embodiment, the processor 214 can access, for example, a lookup table to determine the amount by which the received glucose value should be adjusted based on the temperature or temperature range.

[0104] According to some embodiments, the temperature of the sensor electronics module 126 is correlated with the temperature of the continuous analyte sensor 122 and is used to correct / compensate for offset current temperature drift impairments in the analyte concentration readings. For example, the processor 214 can receive temperature information from the temperature sensor 252 regarding the current temperature of the sensor electronics module 126. The processor 214 or the offset / calibration module 232 can then update the continuous analyte sensor 122 calibration values ​​and adjust the continuous analyte sensor 122 calibration values ​​(which may be set for various temperature values). In other words, any changes or fluctuations in the glucose readings can be sensed and correlated with the temperature changes affecting the sensor electronics module 126.

[0105] Yet another method of compensation can rely on impedance measurements. Impedance can be utilized as a way to change the characteristics of the sensor. In other words, a change in impedance can be associated with some change in the sensor. Compensation measures can therefore be taken based on the impedance. The impedance can be determined based on additional electrodes or the working and reference electrodes themselves. For example, when the continuous analyte sensor is first implanted in the host 120, tissue damage occurs, so that physiological responses to tissue damage can affect sensor operation. Thus, the processor 214 can determine the impedance of the reference electrode. The processor 214 can further measure the wound response, for example, the temperature of the host 120, and thus correlate the wound response and the measured impedance. In this manner, the processor 214 can continue to measure, for example, the impedance of the reference electrode until the impedance returns to a normal or default impedance, at which time the processor 214 can continue to obtain analyte measurements from the continuous analyte sensor 122.

[0106] As an alternative or in combination with some embodiments that utilize an offset current to shift the measurement signal (including noise), the sensitivity of the continuous analyte sensor 122 can be effectively increased by enabling a higher current output. That is, by increasing the current range (i.e., measuring a higher output current), any noise that may be introduced into the measured (current) signal becomes a small percentage of the total current range. It should be noted that multiple ranges can be covered within one sensor design or by multiple generations of sensors. For example, multiple programmable current ranges, e.g., 50 nA, 80 nA, 170 nA, 240 nA, can be utilized instead of just one default current range, typically 16 nA, where the current range is the sum of the measured glucose signal and any added offset current values. Since the noise is a smaller percentage of the increased current range, the increased current range can proactively compensate for the noise. The implementation of these current ranges can be done with software controlled programming registers. In one embodiment, the processor 214 can detect the presence of a new analyte sensor 122 in the analyte sensor system 124. Based on the detection, an appropriate current range can be implemented. For example, the processor 214 can reference a data memory that includes information related to various types of sensors and current ranges for the corresponding types of sensors. Based on the reference, the processor 214 can implement an appropriate current range for the selected analyte sensor 122.

[0107] 4B includes capturing data regarding the fluctuation, which in the case of noise may include using a faster clock 258 or running the clock 258 faster to get a more accurate measurement of the noise causing the fluctuation. A more accurate measurement of the noise may be used not only to detect the fluctuation, but also to better compensate for the noise.

[0108] In some embodiments, the potentiostat 210 may not always or adequately capture noise details. Furthermore, larger noise signals are generally higher in frequency. In the case of non-triboelectric (non-transient) noise, for example, when a host is lying on the continuous analyte sensor 122 and not enough oxygen is received for the enzymes of the continuous analyte sensor 122 to be able to metabolize glucose, the measured glucose signal will be erratic.

[0109] To address these issues, faster sampling rates can be used to capture noise details, such as triboelectric noise details, non-triboelectric / non-transient noise details that do not tend to cancel themselves (notwithstanding the use of current offsets described above), allowing higher sampling (by reducing the sampling interval and / or overclocking) to determine noise trends / characteristics that would normally go unnoticed at slower sampling rates. These identified noise trends / characteristics can be used to better determine the cause / source of the noise, and appropriate corrective / compensatory measures can be implemented.

[0110] As described above, in operation 404, a determination that variation exists is made by processor 214 by comparing reference information, such as previous analyte measurement trends, to the current analyte measurement. Once processor 214 determines the presence of anomalous data or variation in data, processor 214 may adjust the measurement / sampling interval. That is, the measurement / sampling interval used by potentiostat 210 may be reduced, for example, from 30 seconds to 2 seconds. In addition, ASIC 205 may, for example, overclock clock 258 by running it faster. For example, with a signal frequency of 0.5 Hz, only one sample is received every 2 seconds. Overclocking may be used to increase the number of samples received, where the fundamental frequency (32 kHz) of clock 258 is increased, for example, by a factor of 2, 4, 8, etc.

[0111] Another internal noise source can come from some artifacts or particles (i.e., some resistance) that are left between the electrodes during the manufacturing process. Due to these artifacts, some current can flow across the potential difference (voltage) due to this resistance caused by the artifact. This current in turn introduces errors in the measured glucose signal. Thus, some embodiments reduce noise due to parasitic leakage.

[0112] As discussed above, the continuous analyte sensor 122 can have various electrodes, including, for example, reference and working / current electrodes. Similarly, sensors such as the temperature sensor 252, the motion sensor 254, and the pressure sensor 256 also have electrodes that connect to a PCB, for example, on which the ASIC 205 can be implemented. To reduce parasitic leakage currents, the working electrode signal can be surrounded by signals of the same voltage potential. That is, the sensor circuit can be surrounded by the same voltage potential (guard band) to eliminate leakage currents (e.g., current flow from the working electrode to the ground plane). In other words, potential voltage differences that may result in unwanted measurement current flow are eliminated. FIG. 7 illustrates an example implementation of such a guard band. FIG. 7 illustrates an electrode 700 with a guard band 702 implemented around it. In one embodiment, the processor 214 can monitor various voltage signal values, for example, on the sensor electronics module 126, on the electrode, and can compare the various monitored voltage signal values. The comparison can be performed periodically and / or when a signal fluctuation is detected. In one example, the appropriate entity of the processor 214 or ASIC 205 can then suitably cause the connection, disconnection and / or modification of the voltage potential of the guard bands 702. In some embodiments, the guard bands can be implemented in multiple layers of a PCB and can surround the working electrodes, where vias can be used to connect the multiple layers.

[0113] Timing and Battery Fault Compensation In addition to compensating for noise and / or fluctuations in the measured analyte / glucose signal, some embodiments are also directed to detecting and responding to timing errors, battery-related interruptions and failures, and the like.

[0114] Timing errors can occur when the sensor electronics module 126 loses its time due to a disruptive event. In response to such an event, steps can be taken to resynchronize the clock 258. For example, the sensor electronics module 126 can be hit by an ESD event. As a result, EGV data can be transmitted at the wrong time and / or associated with an incorrect timestamp. That is, the ESD event can result in a reset of the clock 258, such that EGV data transmitted after the occurrence of the ESD event is erroneously time-stamped based on a "reset" timestamp instead of an "actual" timestamp.

[0115] To address this type of timing error, and with reference to FIGS. 3 and 8, in operation 800, the processor 314 can compare the current clock time (i.e., the time from the real-time clock 320) to a previously stored clock time (i.e., the time stored in the memory 318) after an interruption in the operation of the sensor electronics module 126 occurs. If the sensor electronics module 126 loses time, for example, due to an ESD event, then in operation 802 the current clock time is synchronized to the previously stored clock time, and in operation 804 the timestamp associated with the EGV data transfer is incremented based on the previously stored clock time. That is, the processor 314 can read the stored time from the memory 318 and increment based on the stored time rather than the time of the real-time clock 320. In this way, for time stamping purposes, this value is used for the next EGV value. In addition, the processor 314 can reset the real-time clock 320 so that it is available again for time stamping of EGV data. It should be noted that the data storage memory 220 or some memory of the processor 314 may buffer the timestamps so that any clock resets can be determined by the processor 314, at which point the processor 314 can perform the comparison described above to obtain the "actual" clock / timestamp. The processor 314 may also recognize an ESD event due to another component analyte sensor system 124 being in a reset or "offline" state for a period of time. Additionally, some type of monitoring circuitry may be implemented to inform the processor 314 that the analyte sensor system 124 is operating properly. If the monitoring circuitry is not operating properly (e.g., via the clock 320), the processor 314 may assume that an event such as an ESD event has occurred.

[0116] With regard to battery-related errors, an ESD event may cause an error in the sensor electronics module 126 resulting in abnormally high glucose values ​​due to high current drain. Thus, some embodiments may detect such high current modes and the sensor electronics module 126 may take steps to exit the high current drain mode. In particular, some embodiments may monitor a general purpose input / output (GPIO) port / pin to detect the high current drain mode. In some embodiments, for example, a "suitable" battery life profile may be stored in the data storage memory 220 so that it can be compared to a sample battery life measurement using a comparison algorithm. A sample battery life measurement may be obtained and compared to a suitable battery life profile based on the expected battery life at a particular time (assuming normal or proper use). In some embodiments, the battery 234 may be disconnected from the sensor electronics module 406 and connected to a dummy load with known impedance or current draw characteristics to determine its current power level. In other embodiments, a coulomb counter may be used to provide a value representing the cumulative amount of charge drawn from the battery 234 to determine the current power level. It should be noted that the battery 234, like the sensor electronics module 126 or its components, may fall victim to a distorted battery life time prediction due to temperature. Thus, much like the embodiments described above, where a temperature sensor 252 is utilized to determine the temperature of the sensor electronics module 126, the continuous analyte sensor 122, etc., the temperature sensor 252 may also be used to determine the operating temperature of the battery 234, and the calculated battery life may be compensated or adjusted based on this operating temperature.

[0117] This comparison can enable the processor 214 to determine, for example, that the current battery life profile is indicative of faster decay than would be expected from a proper battery life profile, which can indicate that the sensor electronics module 126 is experiencing a high current drain mode. Once a high current drain mode is detected, the processor 214 can reset the sensor electronics module 126. It should be noted that this can also prompt a reset or resynchronization of the clock 258 based on a previously stored time, as described above. It should be further noted that for very low current devices such as the sensor electronics module 126, conventional battery monitoring equipment reduces battery life, and the comparison algorithm described above relies on logic for detection that does not significantly impact battery life. As described above, such an embodiment is also an improvement over using fuses / circuit breakers, as adding such circuitry can add noise that requires additional compensation.

[0118] During manufacturing, for example, for testing / quality control purposes, power can be drawn from the battery 234. Thus, before the sensor electronics module 126 is used by a host, it will have suffered a loss of battery power. Thus, some embodiments can switch between a wireless charging mode and a normal, hand-held power supply mode. In particular, and as illustrated in FIG. 9A, the sensor electronics module 126 can have an energy harvesting chip 280 and a charging chip 282 implemented, for example, as part of the ASIC 205. In this way, during a first mode (e.g., during manufacturing), the sensor electronics module 126 can be powered wirelessly using the wireless charger 286, thereby avoiding draining the battery 234. The energy harvesting chip 280 can collect power from the wireless charger 286 and via the charging chip 282, the ASIC 205. In a second mode (e.g., during normal use), the ASIC 205 can draw power from the battery 234. The mode selector 284 can be used to toggle from the first mode to the second mode. The mode selector 284 can be a non-permanent circuit such as a switch, a logical component or a trace that allows the battery 234 to be bypassed in the first mode and connected to the ASIC 205 in the second mode. In some embodiments, the battery 234 can be a rechargeable battery or a separate rechargeable battery 234' can be used as an additional power source. During the first mode, the mode selector 284 can enable wireless charging of the ASIC 205 and / or the rechargeable battery 234' that powers the ASIC 205. During this mode, the rechargeable battery 234' can also be recharged by wireless charging. In the second mode, the battery 234 and / or the rechargeable battery 234 can be used to power the ASIC 205.

[0119] Also, during manufacturing, there may be a lack of information or data logging, making it difficult to trace back battery malfunction issues during normal use (by the host). Thus, some embodiments use enhanced data logging to capture details about the sensor electronics module 126 and / or battery 234 during the manufacturing stage, so that these details can be investigated and / or possibly correlated with issues with the sensor electronics module 126 and / or battery 234 that occur during normal use. In particular, the processor 214 can log (in the data storage memory 220 or a special partition therein that persists throughout the life of the sensor electronics module 126) data regarding the contract manufacturing steps and the status of the sensor electronics module 126 and / or battery 234 (e.g., battery level, number of resets, mode switching, etc.) both before and after being placed into a storage mode prior to use by the host. Alternatively, such data can be transmitted to an external storage device, e.g., a cloud-based server, via the communication port 238, along with information identifying the particular sensor electronics module and / or battery, so as not to impact storage space on the data storage memory 220. Later testing of the sensor electronics module 126 and / or battery 234 can be correlated with this previously stored data. To this end, the battery 234 can have a battery integrated circuit (IC) that can provide identification information about the battery 234. This additional data logging does not adversely affect the lifespan of the battery 234 due to the above-mentioned first mode of wireless charging. In addition to logging the contract manufacturing steps, data can be collected, for example, from the temperature sensor 252 to obtain air temperature data indicative of the temperatures experienced at the sensor electronics module 126 and / or battery 234 during the manufacturing process. Additionally, and according to received sensor information, test analyte measurement signals, etc. during manufacturing, the processor 214 can perform normal pre-use offset, calibration, and other compensation measures as previously described.

[0120] Furthermore, the batteries may have different battery chemistries and may be manufactured or obtained from different manufacturers. Additionally, different models or versions of the sensor electronics module may be used with these different types of batteries. This variability in battery characteristics as well as the characteristics of the sensor electronics module often results in totally inconsistent performance characteristics. Thus, some embodiments allow for reconfiguration of variable parameters in the sensor electronics module 126.

[0121] In particular, each type or model or set of batteries may have their own unique battery performance characteristics or battery profile, which may include, but are not limited to, operating characteristics such as voltage range, sustained current rating, pulse current rating, voltage thresholds, etc. Such battery parameters are used in calculations performed by the firmware / processor of the sensor electronics module 126 over the course of the sensor electronics module's 126 life to enable the sensor electronics module 126 to predict when a given battery will run out of charge / how long the battery will last. As described below, in some embodiments, one or more battery operating parameters (e.g., for different types of batteries) may be transmitted from the server 138 to the sensor electronics module 126 (e.g., via one of the display devices).

[0122] To ensure optimal performance of the sensor electronics module 126, e.g., to avoid unexpected battery drain and potential interruption of transmission of sensor information to one or more display devices 134a-e, in some embodiments, the sensor electronics module 126 can be updated after battery installation. FIG. 9B illustrates example operations performed by the sensor electronics module 126 to achieve battery configuration. As previously mentioned, one or more operating parameters are received at operation 900. At operation 902, performance characteristics of a battery (e.g., battery 234) are monitored over time. At operation 904, the sensor electronics module 126 determines whether the monitored performance characteristics of the battery 234 deviate from a baseline performance (e.g., a known battery profile stored in data storage memory 220) based on the one or more received operating parameters. If so, at operation 906, the one or more operating parameters can be updated, e.g., wirelessly through communication port 238. In this manner, the operation of the sensor electronics module 126, such as EGV transmission characteristics, connection preferences to one or more of the display devices 134a-e, etc., can be configured to suit appropriate performance characteristics of the battery 234.

[0123] In some embodiments, if an operating parameter is entered incorrectly, the boundaries can be used to determine a potential battery problem. That is, and as shown in FIG. 9C at operation 910, one or more operating parameters representing a battery profile are received by the sensor electronics module 126. These operating parameters, examples of which are described above, can be used by firmware in the sensor electronics module 126 to characterize the battery profile. Additionally, boundaries are entered at operation 912 based on the one or more operating parameters. These boundaries can refer to minimum / maximum expected performance characteristics for one or more operating parameters associated with a particular battery. At operation 914, the sensor electronics module 126 determines whether the one or more operating parameters exceed the entered boundaries. If not, no action needs to be taken at 916. That is, if the determination is performed during manufacturing, the sensor electronics module 126 can go into a sleep or low power storage mode until it is powered on by a user. If the determination is performed when the sensor electronics module 126 is already operating, it can continue to operate. However, if the sensor electronics module 126 determines that one or more of the received operating parameters exceed the entered boundaries, the processor 214 may, at operation 918, direct the user interface 222 or the display devices 134a-e to display a notification, issue a warning, or alert a user or manufacturing personnel that the operating parameters require an update. In some embodiments, the sensor electronics module may determine when to provide an alert notification (e.g., for low voltage) based on one of the reconfigurable battery operating parameters (e.g., voltage thresholds) for different types of batteries.

[0124] In some embodiments, as shown in FIG. 9A, a charge pump 288 may be implemented in the analyte sensor system 124 that may increase (e.g., double) the battery voltage of a single battery (e.g., battery 234) for power intensive operations. Thus, in those embodiments, an additional battery may not be needed, thus advantageously saving physical space of the analyte sensor system 124 (i.e., by not installing an extra battery). The charge pump 288 may be internally coupled to the ASIC 205. Furthermore, FIG. 9D shows an embodiment of an equivalent model of the charge pump (voltage doubler) 920. For example, in the model 920, an equivalent resistor 926 has a resistance value Requiv=1 / Cext*Fclock, where Cext is the value of the capacitor 928 and Fclock (Hz) is the frequency of the clock. With a fixed capacitor value of Cext in one embodiment, the value of Fclock determines the equivalent resistance Requiv of the charge pump 288 or 920, which determines the output current capacity of the charge pump (i.e., how much load it can drive). In other words, Fclock and Requiv essentially determine the output voltage Vp.

[0125] In some implementations, the charge pump can be actuated via a feedback control network that can react to load spikes by increasing the Fclock frequency. However, due to the reactive nature of the control mechanism, the output voltage 930 can experience undesired ripples or glitches, as shown in FIG. 9E. In some implementations, the undesired ripples in the output voltage can be eliminated. In such implementations, the processor 214 can identify and determine the schedule or timing at which power-intensive operations (e.g., wireless transmission of sensor data and / or internal database access of sensor data) occur. In addition, the processor 214 can determine the payload of those operations (e.g., power or current consumption associated with wireless transmission of sensor data and / or internal database access of sensor data). Based on the schedule and payload information of the operations, the processor 214 can calculate and set the corresponding values ​​of the operating frequency of the charge pump 920, i.e., Fclock, for each operation at their scheduled times according to the payload information. In one embodiment, the processor 214 can access a database for schedule and payload information of a plurality of operations and can further store the corresponding calculated operating frequency Fclock for each operation. For example, the processor 214 can instruct the charge pump 288 to operate at one of the calculated frequencies (on a predetermined schedule based on the payload information) corresponding to one of the operations. Implementation of such a method minimizes, or in some cases eliminates, voltage ripple or glitches in the output voltage 932 (as shown in FIG. 9F) to ensure steady-state operation of the sensor analyte system 124.

[0126] It should also be noted that various combinations of the above-described embodiments / operational scenarios can be combined in different ways to achieve one or more desired operational characteristics in a continuous analyte measurement system. Although various embodiments have been described in the context of continuous analyte measurement, e.g., continuous glucose monitoring, various embodiments may be adapted for other situations, e.g., monitoring of vital signs.

[0127] As used herein, the term "module" may describe a given unit of functionality that may be performed by one or more embodiments of the present application. As used herein, a module may be implemented using any form of hardware, software, or combination thereof. For example, one or more processors, controllers, ASICs, PLAs, PALs, CPLDs, FPGAs, logic components, software routines, or other mechanisms may be implemented to form a module. Modules, circuits, processors, etc. may be fixed, such as on a printed circuit board (PCB), and may take a variety of forms. In implementation, the various modules described herein may be implemented as separate modules or functions, and the described features may be shared in part or in whole among one or more modules. In other words, as would be apparent to one of ordinary skill in the art after reading this description, the various features and functionality described herein may be implemented in any given application and may be implemented in one or more separate or shared modules in various combinations and permutations. Those skilled in the art will understand that even if various features or elements of functionality are described or claimed individually as separate modules, these features and functionality may be shared among one or more common software and hardware elements, and that such description does not require or imply that separate hardware or software components are used to implement such features or functionality.

[0128] Where components or modules of an application are implemented in whole or in part using software, in one embodiment, these software elements may be implemented to operate on computing or processing circuitry capable of performing the functionality described with respect thereto. One such exemplary computing module that may be used to implement various functions of the systems and methods disclosed herein is shown in FIG. 10. Various embodiments are described with respect to this example computing module 1000. After reading this description, it will become apparent to one skilled in the relevant art how to implement applications using other computing modules or architectures.

[0129] 10, the computing module 1000 may represent, for example, computing or processing capabilities found within a range of self-adjusting displays, desktop, laptop, notebook and tablet computers, portable computing devices (tablets, PDAs, smartphones, cell phones, palmtops, etc.), workstations or other devices with displays, servers, or any other type of special purpose or general purpose computing device that may be desirable or appropriate for a given application or environment. For example, the computing module 1000 may be an embodiment of one of the display devices 134a-e or the sensor electronics module 126. The computing module 1000 may also represent computing capabilities embedded or available within a given device. For example, the computing module may be found in other electronic devices, such as, by way of example, portable computing devices and other electronic devices that may include some form of processing capabilities.

[0130] Computing module 1000 may include one or more processors, controllers, control modules, or other processing devices, such as, for example, processor 1004. Processor 1004 may be implemented using a general-purpose or special-purpose processing engine, such as a microprocessor, controller, or other control logic. In the illustrated example, processor 1004 is connected to bus 1002, although any communication medium may be used to facilitate interaction with other components of computing module 1000 or to communicate externally.

[0131] The computing module 1000 may also include one or more memory modules, referred to herein simply as main memory 1008. For example, a random access memory (RAM) or other dynamic memory may preferably be used to store information and instructions to be executed by the processor 1004. The main memory 1008 may also be used to store temporary variables or other intermediate information during execution of instructions to be executed by the processor 1004. The computing module 1000 may also include a read only memory ("ROM") or other static storage device coupled to the bus 1002 for storing static information and instructions for the processor 1004.

[0132] The computing module 1000 may also include one or more various forms of information storage mechanisms 1010, which may include, for example, a media drive 1012 and a storage interface 1020. The media drive 1012 may include a drive or other mechanism for supporting a fixed or removable storage medium 1014. For example, a hard disk drive, a solid state drive, a magnetic tape drive, an optical disk drive, a compact disk (CD) or digital video disk (DVD) drive (R or RW), or other removable or fixed media drive may be provided. Thus, the storage medium 1014 may include, for example, a hard disk, an integrated circuit assembly, a magnetic tape, a cartridge, an optical disk, a CD or DVD, or other fixed or removable media that is read by, written to, or accessed by the media drive 1012. As these examples show, the storage medium 1014 may include a computer usable storage medium having computer software or data stored therein.

[0133] In alternative embodiments, information storage mechanism 1010 may include other similar means by which computer programs or other instructions or data can be loaded into computing module 1000. Such means may include, for example, fixed or removable storage devices 1022 and interfaces 1020. Examples of such storage devices 1022 and interfaces 1020 may include program cartridges and cartridge interfaces, removable memory (e.g., flash memory or other removable memory modules) and memory slots, PCMCIA slots and cards, and other fixed or removable storage units 1022 and interfaces 1020 by which software and data can be transferred from storage device 1022 to computing module 1000.

[0134] The computing module 1000 may also include a communications interface 1024. The communications interface 1024 may be used to allow software and data to be transferred between the computing module 1000 and an external device, such as a cloud-based server or other remotely located entity. Examples of the communications interface 1024 may include a modem or soft modem, a network interface (e.g., Ethernet, network interface card, WiMedia, IEEE 802.XXX or other interface), a communications port (e.g., USB port, IR port, RS232 port Bluetooth interface or other port) or other communications interface. The software and data transferred via the communications interface 1024 may typically be carried in signals, which may be electronic, electromagnetic (including optical) or other signals that can be exchanged by a given communications interface 1024. These signals may be provided to the communications interface 1024 via a channel 1028. This channel 1028 may carry signals and may be implemented using a wired or wireless communications medium. Some examples of a channel may include a phone line, a cellular link, an RF link, an optical link, a network interface, a local or wide area network, and other wired or wireless communications channels.

[0135] In this document, the terms "computer program medium" and "computer usable medium" are used generally to refer to transitory or non-transitory media (e.g., memory 1008, storage device 1020, medium 1014, and channel 1028). These and other various forms of computer program medium or computer usable medium may be involved in conveying one or more sequences of one or more instructions to a processing device for execution. Such instructions embodied in the medium are generally referred to as "computer program code" or a "computer program product" (which may be categorized in the form of a computer program or other grouping). When executed, such instructions may enable the computing module 1000 to perform the features or functions of the present application as described herein.

[0136] Methods and systems The following methods, sensor electronics and systems are provided.

[0137] Method 1: A computer-implemented method comprising receiving a signal representative of an analyte concentration in a host from an analyte sensor, monitoring the signal, determining whether there is a change in the signal, and compensating for the change in the signal such that an indication of the signal is at least representative of the analyte concentration in the host.

[0138] Method 2: An embodiment of method 1, further comprising determining a cause of said change in said signal.

[0139] Method 3: The embodiment of method 2, wherein determining the cause of the change in the signal includes relating the change in the signal to an event identified by one or more sensors of an analyte sensor system.

[0140] Method 4: An embodiment of method 2 or 3, further comprising at least one of recording and transmitting information regarding the cause of the change in the signal and at least one of the change in the signal to at least one of a remote server, a local data storage memory, and a display device.

[0141] Method 5: An embodiment of Method 1, wherein said change in said signal comprises a noise signal component that is added to said signal representative of said analyte concentration in said host.

[0142] Method 6: The embodiment of Method 5, wherein the source of the noise signal component is internal to an analyte sensor system in which the analyte concentration in the host is determined.

[0143] Method 7: The embodiment of Method 6, wherein the source of the noise signal component comprises circuitry internal to the analyte sensor system.

[0144] Method 8: An embodiment of Method 5, wherein accounting for the change in the signal comprises adding an offset current to the signal representative of the analyte concentration in the host and the noise signal component such that the signal representative of the analyte concentration in the host and the noise signal component are shifted by an amount commensurate with the offset current.

[0145] Method 9: An embodiment of Method 5, further comprising relatively reducing the noise signal component by increasing the sensitivity of an analyte sensor to measure the analyte concentration in the host.

[0146] Method 10: The embodiment of Method 9, wherein increasing the sensitivity of the analyte sensor comprises increasing the current range over which the analyte sensor operates.

[0147] Method 11: The embodiment of Method 8, wherein a source of the noise signal component includes the added offset current.

[0148] Method 12: The embodiment of method 11, further comprising determining the offset current by performing a calibration procedure to at least compensate for the noise signal component resulting from the addition of the offset current.

[0149] Method 13: The embodiment of Method 12, wherein the performing of the calibration procedure includes inhibiting operation of a working electrode of an analyte sensor to measure the analyte concentration in the host to allow measurement of only the offset current.

[0150] Method 14: The embodiment of Method 13, wherein the performing of the calibration procedure further comprises enabling operation of the working electrode, measuring the analyte concentration of the host including the offset current, and subtracting the measured offset current from the measured analyte concentration of the host.

[0151] Method 15: The embodiment of Method 14, wherein the calibration procedure is performed according to one of a predetermined schedule, on a one-time basis, or in real time.

[0152] Method 16: The embodiment of Method 1, wherein the change in the signal comprises a fluctuation caused by temperature drift of an analyte sensor for measuring the analyte concentration in the host.

[0153] Method 17: The embodiment of Method 16, further comprising performing a temperature calibration to compensate for variations in an offset current added to the signal representative of the analyte concentration in the host with temperature.

[0154] Method 18: The embodiment of Method 16, wherein the temperature drift of the analyte sensor is determined based on an impedance measurement of a reference electrode of the analyte sensor.

[0155] Method 19: The embodiment of Method 5, further comprising reducing at least one of the sampling intervals over which the analyte concentration in the host is measured to capture details of the noise signal component by overclocking circuitry of an analyte sensor for measuring the analyte concentration in the host.

[0156] Method 20: An embodiment of Method 5, wherein the source of the noise signal component comprises a current flow induced by an artifact of an overall voltage difference between at least two electrodes of an analyte sensor for measuring the analyte concentration in the host.

[0157] Method 21: An embodiment of Method 5, further comprising implementing a guard band with the same voltage difference to compensate for artifact induced current flow.

[0158] Method 22: The embodiment of Method 5, wherein a source of the noise signal component is external to an analyte sensor system in which the analyte concentration in the host is determined.

[0159] Method 23: Compensating for the noise signal component by at least one of: detecting the noise signal component external to the analyte sensor system via one or more sensors, adding an offset current to the signal representative of the analyte concentration in the host and the noise signal component, and determining the offset current by performing a calibration procedure to compensate for at least the noise signal component resulting from the adding of the offset current. The embodiment of method 22, further comprising:

[0160] Method 24: The embodiment of Method 1, wherein said change in said signal comprises a spike in the analyte concentration in said host.

[0161] Method 25: The embodiment of Method 24, further comprising directly adjusting the analyte concentration value by a predetermined adjustment amount based on one or more factors causing the spike.

[0162] Method 26: A method comprising: comparing a current clock time to a previously stored clock time after experiencing an interruption in operation of a sensor measurement circuit of an analyte sensor system; synchronizing the current clock time to the previously stored clock time; and incrementing a timestamp associated with an EGV data transfer based on the previously stored clock time.

[0163] Method 27: The embodiment of Method 26, wherein a real-time clock by which the current clock time is determined is reset upon the interruption of the operation of the sensor measurement circuitry, the interruption of the operation of the sensor measurement circuitry comprising an electrostatic breakdown event.

[0164] System 28: A system including an analyte sensor adapted to transmit analyte concentration data, and sensor measurement circuitry adapted to receive the analyte concentration data from the sensor and detect changes in the analyte concentration data, where the sensor measurement circuitry compensates for fluctuations in the analyte concentration data that exceed a predetermined threshold.

[0165] System 29: The embodiment of System 28 further including at least one of a memory adapted to store information related to the variation in the analyte concentration data, and a transmitter adapted to transmit information related to the variation to at least one of a remote server and a display device adapted to show the anomalous variation or information derived therefrom.

[0166] System 30: The embodiment of system 28 or 29 that includes one or more environmental sensors that determine environmental conditions potentially causing the variation in the analyte concentration data.

[0167] System 31: The embodiment of system 28 or 29 further comprising an offset current circuit adapted to add an offset current to a signal representing said analyte concentration data and a noise signal component associated with said fluctuation such that said analyte concentration data and said noise signal component are shifted to a level above a zero value.

[0168] System 32: The embodiment of system 31, wherein the offset current circuit is activated to add the offset current in response to a determination that a zero peak value associated with the noise signal component is greater than the signal representing the analyte concentration data.

[0169] System 33: An embodiment of system 31, wherein the offset current circuit adds the offset current according to one or more programmed offset currents.

[0170] System 34: The embodiment of system 33, further comprising a processor adapted to compensate for the noise signal component and subtract the added offset current from the received analyte concentration data to obtain analyte concentration data representative of an actual analyte concentration without the noise signal component.

[0171] System 35: An embodiment of System 34, wherein the processor is further adapted to reduce at least one of the sampling intervals at which the analyte concentration data is measured to capture details of the noise signal component by overclocking the circuitry of the analyte sensor.

[0172] System 36: An embodiment of system 28 further comprising a guard band having the same voltage difference that exists between at least two electrodes of the analyte sensor to compensate for current flow induced by artifacts of the overall voltage difference.

[0173] System 37: The embodiment of system 28, further comprising a processor adapted to directly adjust the analyte concentration data by a predetermined adjustment amount based on one or more factors causing the anomalous variation.

[0174] Sensor electronics 38: sensor electronics including a processor and an offset circuit configured to apply an offset current to a noise-affected received analyte concentration signal in response to the processor's determination of the presence of the noise.

[0175] Sensor Electronics 39: The embodiment of the sensor electronics 38 further comprising a calibration circuit that determines the offset current by compensating for noise caused by the offset circuit.

[0176] Sensor Electronics 40: An embodiment described in sensor electronics 39, wherein the processor or one of the calibration circuits inhibits operation of the working electrode of the analyte sensor to measure the analyte concentration in the host enabling measurement of only the offset current that results in the analyte concentration signal.

[0177] Sensor Electronics 41: An embodiment of sensor electronics 39 in which the processor or one of the calibration circuits enables operation of the working electrode to measure the analyte concentration of the host including the offset current and subtracts the measured offset current from the measured analyte concentration of the host.

[0178] Sensor Electronics 42: An embodiment of the sensor electronics 39 in which the processor or one of the calibration circuits performs a temperature calibration to compensate for variations in the offset current with temperature.

[0179] Sensor Electronics 43: The embodiment described in the sensor electronics 39, further including an energy harvesting chip, a charging chip and a mode selector for switching between wireless charging mode and battery power supply mode.

[0180] Sensor electronics 44: An embodiment described in sensor electronics 43 in which a wireless charger wirelessly powers the sensor electronics via the energy harvesting chip adapted to collect power from the charging chip during a first mode.

[0181] Sensor electronics 45: An embodiment of sensor electronics 44 in which a battery powers the sensor electronics in the second mode and the battery is bypassed in the first mode.

[0182] Method 46: A method comprising: receiving at a processor of a system operating under power provided by the battery one or more operating parameters associated with a battery; monitoring a performance characteristic of the battery; determining whether the monitored performance characteristic deviates from a reference performance characteristic based on the one or more received operating parameters; and wirelessly updating the one or more operating parameters in response to a determination that the monitored performance characteristic deviates from the reference performance characteristic.

[0183] Method 47: The embodiment of Method 46, wherein the reference performance characteristic comprises a known profile associated with the battery.

[0184] Method 48: The embodiment of method 46, further comprising adapting operation of a sensor electronics powered by the battery according to the updated performance characteristics of the battery.

[0185] Method 49: A method comprising: receiving, at a processor controlling a sensor measurement circuit, one or more operating parameters representative of a battery profile; receiving a boundary input based on the one or more operating parameters; determining whether the one or more received operating parameters are within a range of the received boundary input; and, when it is determined that the one or more received operating parameters fall outside of a range of the received boundary input, sending a notification to a user interface associated with the sensor measurement circuit that the one or more operating parameters require an update process.

[0186] Method 50: The embodiment of Method 49, wherein the boundary input comprises minimum and maximum expected performance characteristics associated with the one or more operating parameters.

[0187] Method 51: A method comprising determining schedule information for an operation of an analyte sensor system, identifying payload information associated with the operation, calculating an operating frequency of a charge pump according to the payload and schedule information, and instructing the charge pump to operate at the calculated operating frequency during occurrence of the operation.

[0188] Method 52: The embodiment of method 51, wherein the action includes transmitting sensor data from the analyte sensor system.

[0189] While the present disclosure has been illustrated and described in detail in the drawings and foregoing, such illustration and description should be considered as illustrative or exemplary and not restrictive. The present disclosure is not limited to the disclosed embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed disclosure, from a study of the drawings, the disclosure, and the appended claims.

[0190] All references cited herein are incorporated herein by reference in their entirety. To the extent that publications and patents or patent applications incorporated by reference conflict with disclosures contained in this specification, this specification is intended to supersede and / or take precedence over any such conflicting material.

[0191] Unless otherwise specified, all terms (including technical and scientific terms) should be given their ordinary and customary meaning to those skilled in the art and should not be limited to special or customized meanings unless expressly so specified herein. It should be noted that the use of a particular term when describing a particular feature or aspect of the present disclosure should not be interpreted as meaning that the term is redefined herein to be limited to include any specific feature of the function or aspect of the present disclosure to which the term relates. Terms and expressions used in this application and variations thereof should be interpreted as expansive as opposed to restrictive, unless expressly stated otherwise, particularly in the appended claims. As an example of the foregoing, the term "including" should be read as meaning "including, without limitation," "including but not limited to," and the like. As used herein, the term "comprising" is synonymous with "including," "containing," or "characterized by" and is inclusive or expansive and does not exclude additional, unrecited elements or method steps. The term "having" should be interpreted as "having at least." The term "includes" should be interpreted as "includes but is not limited to." The term "examples" is used to provide representative examples of the items under discussion and is not an exhaustive or limiting list thereof.Adjectives (e.g., adjectives such as "known," "normal," "standard," and words of similar import should not be construed as limiting the items described to those items available in a given period or at a given time, but instead should be read to embrace known, usual, or standard technology that may be available now or at any time in the future. And terms such as "preferably," "preferred," "desired," or "desirable" and similar imports should be used to indicate that a particular feature is critical, essential, or even important to the structure or function of the disclosure. It should not be understood to mean that the terms "and" and "subject matter" are used interchangeably, but instead should be understood as merely intended to highlight alternative or additional features that may or may not be utilized in a particular embodiment. Similarly, items of a group joined with the conjunction "and" should not be read as requiring that any one of those items be present in the group, but rather should be read as "and / or" unless expressly stated otherwise. Similarly, items of a group joined with the conjunction "or" should not be read as requiring mutual exclusivity between the group, but rather should be read as "and / or" unless expressly stated otherwise.

[0192] When a range of values ​​is given, it is understood that the upper and lower limits, as well as every value between the upper and lower limits of the range, are included within the embodiments.

[0193] With respect to the use of substantially any plural and / or singular term herein, those skilled in the art can convert from plural to singular and / or from singular to plural as appropriate to the context and / or application. Various singular / plural permutations may be expressly set forth herein for clarity. The indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain means are recited in mutually different dependent claims does not indicate that a combination of these means cannot be used to advantage. Any reference signs in the claims should not be interpreted as limiting the scope.

[0194] It will be further understood by those skilled in the art that when a specific number is intended in an introduced claim recitation, such intent is expressly stated in the claim, and in the absence of such recitation, no such intent exists. For example, as an aid to understanding, the following appended claims may include the use of the introductory phrases "at least one" and "one or more" to introduce a claim recitation. However, even when the same claim includes the introductory phrases "one or more" or "at least one" and an indefinite article such as "a" or "an", the use of such phrases should not be interpreted as meaning that the introduction of a claim recitation with the indefinite article "a" or "an" limits any particular claim that includes such an introduced claim recitation to an embodiment that includes only such recitation (e.g., "a" or "an" should be interpreted as meaning "at least one" or "one or more"). The same is true for the use of definite articles used to introduce claim recitations. In addition, even when a particular number of introduced claim recitations is explicitly recited, one of ordinary skill in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., a mere "two recitations" without other qualifiers typically means at least two recitations or more than two recitations). Furthermore, in instances where a notation similar to "at least one of A, B, and C, etc." is used, such structure is generally intended in the sense that one of ordinary skill in the art would understand the notation (e.g., "a system having at least one of A, B, and C" includes, but is not limited to, a system having only A, only B, only C, both A and B, both A and C, both B and C, and / or all of A, B, and C, etc.).In instances where notation like "at least one of A, B, or C, etc." is used, such structure is generally intended in the sense that one of ordinary skill in the art would understand the notation (e.g., "a system having at least one of A, B, or C" includes, but is not limited to, systems having only A, only B, only C, both A and B, both A and C, both B and C, and / or all of A, B, and C, etc.). One of ordinary skill in the art will further appreciate that substantially any disjunctive word and / or disjunctive phrase expressing two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibility of including one of the terms, either of the terms, or both of the terms. For example, the phrase "A or B" will be understood to include the possibilities of "A or B" or "A and B."

[0195] All numbers expressing amounts of ingredients, reaction conditions, and so forth used in the specifications are to be understood as being modified in all instances by the term "approximately." Accordingly, unless indicated to the contrary, the numerical parameters set forth herein are approximations that may vary depending upon the desired properties sought to be obtained. At the very least, and not as an attempt to limit the scope of the doctrine of equivalents to the scope of any claims in any application claiming priority to this application, each numerical parameter should be construed in light of the number of significant digits and ordinary rounding approaches.

[0196] Furthermore, although the foregoing has been described in some detail by way of illustration and example for purposes of clarity and understanding, it will be apparent to those skilled in the art that certain changes and modifications can be practiced. Therefore, the descriptions and examples should not be construed as limiting the scope of the disclosure to the specific embodiments and examples described herein, but rather are intended to cover all modifications and variations that come within the true scope and spirit of the disclosure. [Explanation of symbols]

[0197] 100 Continuous Analyte Monitoring System 122 Continuous Analyte Sensors 124 Analyte Sensor System 126 Sensor Electronics Module 128 "uplink" signal 138 Long Distance Downlink Signal 140 Remote Server

Claims

1. receiving a signal representative of an analyte concentration in the host from the analyte sensor; monitoring the signal; determining whether there is a change in the signal; and compensating for the change in the signal such that a representation of the signal is at least representative of the analyte concentration in the host.

2. The computer-implemented method of claim 1 , further comprising determining a cause of the change in the signal.

3. The computer-implemented method of claim 2 , wherein determining the cause of the change in the signal comprises relating the change in the signal to an event identified by one or more sensors of an analyte sensor system.

4. 4. The computer-implemented method of claim 2 or 3, further comprising at least one of recording and transmitting information regarding the cause of the change in the signal and at least one of the change in the signal to at least one of a remote server, a local data storage memory, and a display device.

5. The computer-implemented method of claim 1 , wherein the change in the signal comprises a noise signal component that is added to the signal representative of the analyte concentration in the host.

6. 6. The computer-implemented method of claim 5, wherein a source of the noise signal component is internal to an analyte sensor system in which the analyte concentration in the host is determined.

7. The computer-implemented method of claim 6 , wherein the source of the noise signal component comprises circuitry internal to the analyte sensor system.

8. 6. The computer-implemented method of claim 5, wherein accounting for the change in the signal comprises adding an offset current to the signal representative of the analyte concentration in the host and to the noise signal components such that the signal representative of the analyte concentration in the host and to the noise signal components are shifted by an amount commensurate with the offset current.

9. 6. The computer-implemented method of claim 5, further comprising relatively reducing the noise signal component by increasing a sensitivity of an analyte sensor to measure the analyte concentration in the host.

10. 10. The computer-implemented method of claim 9, wherein increasing the sensitivity of the analyte sensor comprises increasing a current range over which the analyte sensor operates.

11. The computer-implemented method of claim 8 , wherein a source of the noise signal component includes the added offset current.

12. 12. The computer-implemented method of claim 11, further comprising determining the offset current by performing a calibration procedure to at least compensate for the noise signal component resulting from the addition of the offset current.

13. 13. The computer-implemented method of claim 12, wherein the performing of the calibration procedure includes inhibiting operation of a working electrode of an analyte sensor to measure the analyte concentration in the host to allow measurement of only the offset current.

14. 14. The computer-implemented method of claim 13, wherein the performing of the calibration procedure further comprises enabling operation of the working electrode, measuring the analyte concentration in the host including the offset current, and subtracting the measured offset current from the measured analyte concentration in the host.

15. 15. The computer-implemented method of claim 14, wherein the calibration procedure is performed according to one of a predetermined schedule, on a one-time basis, or in real time.

16. 10. The computer-implemented method of claim 1, wherein the change in the signal comprises a fluctuation caused by temperature drift of an analyte sensor for measuring the analyte concentration in the host.

17. 17. The computer-implemented method of claim 16, further comprising performing a temperature calibration to compensate for variations in an offset current added to the signal representing the analyte concentration in the host with temperature.

18. 17. The computer-implemented method of claim 16, wherein the temperature drift of the analyte sensor is determined based on an impedance measurement of a reference electrode of the analyte sensor.

19. 6. The computer-implemented method of claim 5, further comprising reducing at least one of the sampling intervals at which the analyte concentration in the host is measured to capture details of the noise signal component by overclocking a circuit of an analyte sensor for measuring the analyte concentration in the host.

20. 6. The computer-implemented method of claim 5, wherein a source of the noise signal component comprises an artifact-induced current flow of an overall voltage difference between at least two electrodes of an analyte sensor for measuring the analyte concentration in the host.

21. The computer-implemented method of claim 5 , further comprising implementing a guard band having the same voltage difference to compensate for artifact induced current flow.

22. 6. The computer-implemented method of claim 5, wherein a source of the noise signal component is external to an analyte sensor system in which the analyte concentration in the host is determined.

23. 23. The computer-implemented method of claim 22, further comprising: detecting the noise signal component external to the analyte sensor system via one or more sensors and compensating for the noise signal component by at least one of: adding an offset current to the signal representative of the analyte concentration in the host and the noise signal component; and determining the offset current by performing a calibration procedure to compensate for at least the noise signal component resulting from the adding of the offset current.

24. The computer-implemented method of claim 1 , wherein the change in the signal comprises a spike in the analyte concentration in the host.

25. 25. The computer-implemented method of claim 24, further comprising directly adjusting the analyte concentration value by a predetermined adjustment amount based on one or more factors causing the spike.

26. comparing a current clock time to a previously stored clock time after experiencing an interruption in operation of the sensor measurement circuitry of the analyte sensor system; synchronizing said current clock time with said previously stored clock time; and incrementing a timestamp associated with the EGV data transfer based on the previously stored clock time.

27. 27. The method of claim 26, wherein a real-time clock by which the current clock time is determined is reset upon the interruption of the operation of the sensor measurement circuitry, the interruption of the operation of the sensor measurement circuitry comprising an electrostatic discharge event.

28. an analyte sensor adapted to transmit analyte concentration data; a sensor measurement circuit adapted to receive analyte concentration data from the sensor and detect changes in the analyte concentration data, the sensor measurement circuit compensating for fluctuations in the analyte concentration data that exceed a predetermined threshold; A system including:

29. 30. The system of claim 28, further comprising at least one of: a memory adapted to store information related to the variations in the analyte concentration data; and a transmitter adapted to transmit information related to the variations to at least one of a remote server and a display device adapted to show the abnormal variations or information derived therefrom.

30. 30. The system of claim 28 or 29, comprising one or more environmental sensors that determine environmental conditions potentially causing the variation in the analyte concentration data.

31. 30. The system of claim 28 or 29, further comprising an offset current circuit adapted to add an offset current to a signal representing the analyte concentration data and a noise signal component associated with the fluctuation such that the analyte concentration data and the noise signal component are shifted to a level above a zero value.

32. 32. The system of claim 31, wherein the offset current circuit is activated to add the offset current in response to determining that a zero peak value associated with the noise signal component is greater than the signal representing the analyte concentration data.

33. 32. The system of claim 31, wherein the offset current circuitry adds the offset current according to one or more programmed offset currents.

34. 34. The system of claim 33, further comprising a processor adapted to compensate for the noise signal component and subtract the added offset current from the received analyte concentration data to obtain analyte concentration data representative of an actual analyte concentration without the noise signal component.

35. 35. The system of claim 34, wherein the processor is further adapted to reduce at least one of a sampling interval at which the analyte concentration data is measured to capture details of the noise signal component by overclocking circuitry of the analyte sensor.

36. 30. The system of claim 28, further comprising a guard band having the same voltage difference that exists between at least two electrodes of the analyte sensor to compensate for current flow induced by artifacts of the overall voltage difference.

37. 30. The system of claim 28, further comprising a processor adapted to directly adjust the analyte concentration data by a predetermined adjustment amount based on one or more factors causing the anomalous variation.

38. A processor; and an offset circuit configured to apply an offset current to a noise-affected received analyte concentration signal in response to a determination by said processor of the presence of said noise.

39. 40. The sensor electronics of claim 38, further comprising a calibration circuit that determines the offset current by compensating for noise introduced by an offset circuit.

40. 40. The sensor electronics of claim 39, wherein one of the processor or the calibration circuitry inhibits operation of a working electrode of an analyte sensor to measure the analyte concentration of a host enabling measurement of only the offset current resulting in the analyte concentration signal.

41. 40. The sensor electronics of claim 39, wherein one of the processor or the calibration circuitry enables operation of a working electrode to measure the analyte concentration in a host including the offset current and subtracts the measured offset current from the measured analyte concentration in the host.

42. 40. The sensor electronics of claim 39, wherein one of the processor or the calibration circuitry performs a temperature calibration to compensate for variations in the offset current with temperature.

43. 40. The sensor electronics of claim 39, further comprising an energy harvesting chip, a charging chip and a mode selector for switching between a wireless charging mode and a battery power supply mode.

44. 44. The sensor electronics of claim 43, wherein a wireless charger wirelessly powers the sensor electronics during a first mode via the energy harvesting chip adapted to harvest power from the charging chip.

45. 45. The sensor electronics of claim 44, wherein a battery powers the sensor electronics in the second mode and the battery is bypassed in the first mode.

46. receiving, at a processor of a system operating under power provided by the battery, one or more operating parameters associated with the battery; monitoring performance characteristics of the battery; determining whether the monitored performance characteristic deviates from a reference performance characteristic based on the one or more received operating parameters; and wirelessly updating the one or more operating parameters in response to a determination that the monitored performance characteristic deviates from the reference performance characteristic.

47. 47. The method of claim 46, wherein the baseline performance characteristic comprises a known profile associated with the battery.

48. 47. The method of claim 46, further comprising adapting operation of sensor electronics powered by the battery according to the updated performance characteristics of the battery.

49. receiving, at a processor controlling the sensor measurement circuitry, one or more operating parameters representative of a battery profile; receiving a boundary input based on the one or more operating parameters; determining whether the one or more received operating parameters are within the range of the received boundary input; and when it is determined that the one or more received operating parameters fall outside of the received boundary inputs, sending a notification to a user interface associated with the sensor measurement circuitry that the one or more operating parameters require an update process.

50. 50. The method of claim 49, wherein the boundary inputs include minimum and maximum expected performance characteristics associated with the one or more operating parameters.

51. determining schedule information for operation of the analyte sensor system; identifying payload information associated with the operation; calculating an operating frequency of a charge pump according to the payload and schedule information; instructing said charge pump to operate at said calculated operating frequency during said occurrence of said operation.

52. 52. The method of claim 51, wherein the action comprises transmitting sensor data from the analyte sensor system.

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