Systems and methods for potentiometric-based analyte measurements

Abstract

Aspects of the present disclosure provide a wearable device for potentiometric-based analyte measurements. The wearable device includes a transcutaneous analyte sensor configured to perform potentiometric-based measurements of an analyte concentration level of a user. The transcutaneous analyte sensor includes a working electrode for receiving a first input signal and a reference electrode for receiving a second input signal. The wearable device also include one or more operational amplifiers configured to receive the first input signal and the second input signal and output an output signal representing a differential between the first input signal and second input signal. Additionally, the wearable device includes an analog to digital converter (ADC) configured to convert the output signal to a digital signal and one or more processors configured to receive the digital signal from the ADC and process the digital signal to determine the analyte concentration level of the user.

Description

SYSTEMS AND METHODS FOR POTENTIOMETRIC-BASED ANALYTE MEASUREMENTSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and benefit of U.S. Provisional Patent Application No. 63 / 666,042, filed June 28, 2024, which is hereby assigned to the assignee hereof and hereby expressly incorporated by reference herein in its entirety as if fully set forth below and for all applicable purposes.BACKGROUND

[0002] The present application relates generally to medical devices such as analyte sensors, and more particularly to systems, devices, and methods related to potentiometric-based analyte measurements.

[0003] In vivo analyte sensors can typically be configured to analyze a single analyte using an enzyme to provide specificity for the single analyte. Determining concentrations of multiple analytes of physiological relevance can be desirable in certain medical instances. For example, the concentration of an ion, such as sodium, potassium, magnesium, calcium, or ammonium, in a host’s biological fluid can provide important information about that host’s health status. Illustratively, the potassium ion (K+) is a biomarker of cardiovascular disease. In another example, the potassium ion (K+) is a biomarker of kidney disease. Indeed, in the US, about 14.8M individuals with diabetes are diagnosed with kidney disease, for example, impaired renal function; these patients may benefit from frequent measurement of blood potassium to assess kidney function and guide therapies, which may include oral medications, at one end of the spectrum, to dialysis on the other. In yet another example, the potassium ion (K+) is a biomarker of both cardiovascular disease and kidney disease.

[0004] This background is provided to introduce a brief context for the summary and detailed description that follow. This background is not intended to be an aid in determining the scope of the claimed subject matter nor be viewed as limiting the claimed subject matter to implementations that solve any or all of the disadvantages or problems presented above.SUMMARY

[0005] Certain embodiments of the present disclosure provide a wearable device for performing analyte measurements. The wearable device includes a transcutaneous analyte sensor configured to perform potentiometric-based measurements of an analyte concentration level of a user. In some embodiments, the transcutaneous analyte sensor includes a working electrode for receiving a first input signal and a reference electrode for receiving a second input signal. In some embodiments, the first input signal and the second input signal are associated with the analyte concentration level of the user. In some embodiments, the wearable device may also include an application specific integrated circuit (ASIC). The ASIC may include one or more operational amplifiers configured to receive the first input signal and the second input signal output an output signal representing a differential between the first input signal and second input signal. The ASIC may also include an analog to digital converter (ADC) configured to convert the output signal to a digital signal. The wearable device may also include one or more processors configured to receive the digital signal from the ADC and process the digital signal to determine the analyte concentration level of the user. The wearable device may also include a printed circuit board (PCB) configured to operatively connect at least the ASIC, the ADC, and the one or more processors.

[0006] Certain embodiments of the present disclosure provide a method for performing analyte measurements by a wearable device. The method includes performing, by a transcutaneous analyte sensor, at least one potentiometric-based measurement of an analyte concentration level of a user of the wearable device; receiving, at one or more operational amplifiers of an application specific integrated circuit (ASIC) of the wearable device, a first input signal from a working electrode of the transcutaneous analyte sensor based on performing the at least one potentiometric-based measurement; receiving, at the one or more operational amplifiers of the ASIC, a second input signal from a reference electrode of the transcutaneous analyte sensor based on performing the at least one potentiometric-based measurement, wherein the first input signal and the second input signal are associated with the analyte concentration level of the user; outputting, from the one or more operational amplifiers to an analog to digital converter (ADC) of the wearable device, an output signal representing a differential between the first input signal and second input signal; converting, by the ADC, the output signal to a digital signal; receiving, by one or more processors of the wearable device, the digital signal from the ADC and processing the digital signal to determine the analyteconcentration level of the user, wherein the ASIC, the ADC, and the one or more processors are operatively coupled by a printed circuit board (PCB).

[0007] Other aspects provide: an apparatus operable, configured, or otherwise adapted to perform the aforementioned methods as well as those described elsewhere herein; a non-transitory, computer-readable media comprising instructions that, when executed by one or more processors of an apparatus, cause the apparatus to perform the aforementioned methods as well as those described elsewhere herein; a computer program product embodied on a computer-readable storage medium comprising code for performing the aforementioned methods as well as those described elsewhere herein; and an apparatus comprising means for performing the aforementioned methods as well as those described elsewhere herein. By way of example, an apparatus may comprise a processing system, a device with a processing system, or processing systems cooperating over one or more networks.

[0008] The following description and the appended figures set forth certain features for purposes of illustration.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 illustrates an example diabetes management system, according to some embodiments disclosed herein.

[0010] FIG. 2 illustrates a more detailed view of a health management system including a display device that is communicatively coupled to an analyte sensor system, according to some embodiments disclosed herein.

[0011] FIG. 3A is an example analyte sensor system, in accordance with some embodiments.

[0012] FIG. 3B is an example analyte sensor system, in accordance with some embodiments.

[0013] FIG. 3C illustrates aspects of an example analyte sensor system, in accordance with some embodiments.

[0014] FIG. 4 illustrates an example application- specific integrated circuit (ASIC) for reduced leakage currents and noise, in accordance with some embodiments.

[0015] FIG. 5 illustrates an example ASIC for reduced leakage currents and noise, in accordance with some embodiments.

[0016] FIG. 6 illustrates an example wearable device including bonding wires, in accordance with some embodiments.

[0017] FIG. 7 illustrates an example wearable device including electrical traces on a printed circuit board (PCB) used to connect a working electrode and reference electrode of a continuous analyte sensor to an ASIC, in accordance with some embodiments.

[0018] FIGS. 8A, 8B, 8C, and 8D illustrate various views of an electrical trace, in accordance with some embodiments.

[0019] FIGS. 9A, 9B, and 9C illustrate a wearable device for continuous potentiometric-based analyte measurements of a user, in accordance with some embodiments.

[0020] FIG. 10 depicts a method for performing analyte measurements, according to some embodiments disclosed herein.

[0021] FIG. 11 depicts aspects of an example communications device, according to some embodiments disclosed herein.DETAILED DESCRIPTION

[0022] Aspects of the present disclosure provide techniques, including apparatuses, methods, processing systems, and computer-readable mediums, for reducing leakage currents and conserving battery power associated with potentiometric-based analyte measurements.Introduction to Health Management Systems

[0023] FIG. 1 depicts a health management system 100 including an example continuous analyte sensor system (SS) 8 having continuous analyte sensor(s) and sensor electronics, in accordance with certain aspects of the present disclosure. For example, SS 8 may be configured to continuously monitor one or more analytes of a user 50, in accordance with certain aspects of the present disclosure.

[0024] As shown, SS 8 includes sensor electronics module 12 and one or more analyte sensor(s) 10 (individually referred to herein as analyte sensor 10 and collectively referred to herein as analyte sensors 10) associated with sensor electronics module 12. In some embodiments, the one or more analyte sensor(s) 10 may comprise one or more continuous analyte sensors configured to provide continuous analyte concentration level measurements. Sensor electronics module 12 may be in wireless communication (e.g.,directly or indirectly) with one or more of display devices 110, 120, 130, and 140, and / or server system 134.

[0025] In certain embodiments, the analyte sensor(s) 10 may comprise one or more sensors for detecting and / or measuring analyte(s). The analyte sensor(s) 10 may be a multi-analyte sensor configured to continuously measure two or more analytes or a single analyte sensor configured to continuously measure a single analyte as a non-invasive device, a subcutaneous device, a transcutaneous device, a transdermal device, and / or an intravascular device. In certain embodiments, the analyte sensor(s) 10 may be configured to continuously measure analyte concentration levels of the user 50 using one or more techniques, such as enzymatic techniques, chemical techniques, physical techniques, electrochemical techniques, potentiostatic techniques, potentiometric techniques, impedimetric techniques, spectrophotometric techniques, polarimetric techniques, calorimetric techniques, iontophoretic techniques, radiometric techniques, immunochemical techniques, and the like. The term “continuous,” as used herein, can mean fully continuous, semi-continuous, periodic, etc. In certain aspects, the analyte sensor(s) 10 provides a data stream indicative of the concentration of one or more analytes of the user 50. The data stream may include raw data signals, which are then converted into a calibrated and / or filtered data stream used to provide estimated analyte value(s) to the user 50.

[0026] In certain embodiments, the analyte sensor(s) 10 may be a multi-analyte sensor, configured to continuously measure one or more analytes in a body of the user 50. In some embodiments, the one or more analytes may include at least one of sodium ions, potassium ions, hydrogen ions, lithium ions, magnesium ions, calcium ions, chloride ions, sulfite ions, sulfate ions, phosphate ions, ammonium ions, manganese ions, uric acid, urea, ketones, and / or glucose.

[0027] In certain embodiments, the analyte sensor(s) 10 may comprise a percutaneous wire that has a proximal portion coupled to the sensor electronics module 12 and a distal portion with several electrodes, such as a measurement electrode and a reference electrode. The measurement (or working) electrode may be coated, covered, treated, embedded, etc., with one or more chemical molecules that react with a particular analyte, and the reference electrode may provide a reference electrical voltage. The measurement electrode may generate the analog electrical signal, which is conveyed along a conductor that extends from the measurement electrode to the proximal portionof the percutaneous wire that is coupled to the sensor electronics module 12. After the SS 8 has been applied to epidermis of the user 50, analyte sensor(s) 10 penetrates the epidermis, and the distal portion extends into the dermis and / or subcutaneous tissue under epidermis. Other configurations of analyte sensor(s) 10 may also be used, such as a multianalyte sensor that includes multiple measurement electrodes, each generating an analog electrical signal that represents the concentration levels of a particular analyte.

[0028] Generally, a single-analyte sensor generates an analog electrical signal that is proportional to the concentration level of a particular analyte. Similarly, each multianalyte sensor generates multiple analog electrical signals, and each analog electrical signal is proportional to the concentration level of a particular analyte. As an illustrative example, analyte sensor(s) 10 may include a single- analyte sensor configured to measure glucose concentration levels, and another single-analyte sensor configured to measure concentration levels of another analyte of the user 50, such as at least one of a sodium ion concentration level, a potassium ion concentration level, a hydrogen ion concentration level, a lithium ion concentration level, a magnesium ion concentration level, a calcium ion concentration level, a chloride ion concentration level, a sulfite ion concentration level, a sulfate ion concentration level, a manganese concentration level, a phosphate ion concentration level, an ammonium ion concentration level, a uric acid concentration level, a urea concentration level, and / or a ketone concentration level. As another illustrative example, analyte sensor(s) 10 may include a single- analyte sensor configured to measure glucose concentration levels, and one or more multi-analyte sensors configured to measure a sodium ion concentration level, a potassium ion concentration level, a hydrogen ion concentration level, a lithium ion concentration level, a magnesium ion concentration level, a calcium ion concentration level, a chloride ion concentration level, a sulfite ion concentration level, a sulfate ion concentration level, a manganese concentration level, a manganese concentration level, a phosphate ion concentration level, an ammonium ion concentration level, a uric acid concentration level, a urea concentration level, a ketone concentration level, a concentration of lactate, a concentration level of creatinine, etc. As yet another illustrative example, analyte sensor(s) 10 may include a multi-analyte sensor configured to measure glucose concentration levels, a sodium ion concentration level, a potassium ion concentration level, a hydrogen ion concentration level, a lithium ion concentration level, a magnesium ion concentration level, a calcium ion concentration level, a chloride ion concentrationlevel, a sulfite ion concentration level, a sulfate ion concentration level, a manganese concentration level, a manganese concentration level, a phosphate ion concentration level, an ammonium ion concentration level, a uric acid concentration level, a urea concentration level, a ketone concentration level, a concentration of lactate, a concentration level of creatinine, etc.

[0029] Accordingly, analyte sensor(s) 10 is configured to generate at least one analog electrical signal that is proportional to the concentration level of a particular analyte, and sensor electronics module 12 is configured to convert the analog electrical signal into an analyte sensor count values, calibrate the analyte sensor count values based on the sensitivity profile of the analyte sensor(s) 10 to generate measured analyte concentration levels, and transmit the measured analyte concentration level data, including the measured analyte concentration levels, to a display device, such as display devices 210, 220, 230, and / or 240, via a wireless connection. For example, sensor electronics module 12 may be configured to sample the analog electrical signal at a particular sampling period (or rate), such as every 1 second (1 Hz), 5 seconds, 10 seconds, 30 seconds, 1 minute, 3 minutes, 5 minutes, etc., and to transmit the measured analyte concentration data to the display device at a particular transmission period (or rate), which may be the same as (or longer than) the sampling period, such as every 1 minute (0.016 Hz), 5 minutes, 10 minutes, 30 minutes, at the conclusion of the wear period, etc. Depending on the sampling and transmission periods, the measured analyte concentration data transmitted to the display device include at least one measured analyte concentration level having an associated time tag, sequence number, etc. Additional details regarding analyte concentration level measurement and the configuration of the analyte sensor(s) 10 and sensor electronics module 12 may be found in one or more of (1) U.S. NonProvisional Patent Application Serial No. 18 / 241,658 filed on September 1, 2023 and entitled, “DEVICES AND METHODS FOR MEASURING A CONCENTRATION OF A TARGET ANALYTE IN A BIOLOGICAL FLUID IN VIVO,” (2) U.S. Provisional Patent Application Serial No. 63 / 268,417 filed on February 23, 2022 and entitled, “SENSING SYSTEMS AND METHODS FOR PROVIDING DECISION SUPPORT AROUND KIDNEY DISEASE,” (3) U.S. Provisional Patent Application Serial No. 63 / 365,702 filed on June 1, 2022 and entitled, “DIAGNOSIS AND DECISION SUPPORT FOR DIABETES IN PATIENTS WITH KIDNEY DISEASE,” (4) U.S. Provisional Patent Application Serial No. 63 / 376,673 filed on September 22, 2022 andentitled, “SENSING SYSTEMS AND METHODS FOR DIAGNOSING KIDNEY DISEASE,” (5) U.S. Provisional Patent Application Serial No. 63 / 387,078 filed on December 12, 2022 and entitled, “DECISION SUPPORT TECHNIQUES USING PHYSIOLOGICAL PROFILES,” (6) U.S. Provisional Patent Application Serial No. 63 / 377,332 filed on September 27, 2022 and entitled, “SENSING SYSTEMS AND METHODS FOR PROVIDING DECISION SUPPORT AROUND KIDNEY DISEASE AND / OR DIABETES,” (7) U.S. Non-Provisional Patent Application Serial No. 18 / 173,753 filed on February 23, 2023 and entitled, “SENSING SYSTEMS AND METHODS FOR PROVIDING DECISION SUPPORT AROUND KIDNEY HEALTH and / or Diabetes,” (8) U.S. Non-Provisional Patent Application Serial No. 18 / 326,985 filed on May 31, 2023 and entitled, “SYSTEMS AND METHODS FOR MONITORING, DIAGNOSIS, AND DECISION SUPPORT FOR DIABETES IN PATIENTS WITH KIDNEY DISEASE,” (9) U.S. Non-Provisional Patent Application Serial No. 18 / 327,012 filed on May 31, 2023 and entitled, “SENSING SYSTEMS AND METHODS FOR DIAGNOSING KIDNEY DISEASE,” and (9) U.S. Non-Provisional Patent Application Serial No. 18 / 327,014 filed on May 31, 2023 and entitled, “SYSTEMS AND METHODS FOR OPTIMIZING TREATMENT USING PHYSIOLOGICAL PROFILES,” all of which are incorporated herein by reference in their entireties.

[0030] In certain embodiments, analyte sensor(s) 10 may incorporate a thermocouple within, or alongside, the percutaneous wire to provide an analog temperature signal to the sensor electronics module 12, which may be used to correct the analog electrical signal or the measured analyte data for temperature. In other embodiments, the thermocouple may be incorporated into the sensor electronics module 12 above the adhesive pad, or, alternatively, the thermocouple may contact the epidermis of the patient through openings in the adhesive pad.

[0031] In certain embodiments, sensor electronics module 12 includes electronic circuitry associated with measuring and processing the continuous analyte sensor data, including prospective algorithms associated with processing and calibration of the sensor data. Sensor electronics module 12 can be physically coupled to analyte sensor(s) 10 and can be integral with (non-releasably attached to) or releasably attachable to analyte sensor(s) 10. Sensor electronics module 12 may include hardware, firmware, and / or software that enable measurement of levels of analyte(s) via analyte sensor(s) 10. For example, sensor electronics module 12 can include an electrochemical analog front end(e.g., a potentiostat, galvanostat, coulostat, etc.), a power source for providing power to the sensor (including power switches and controlling logic), other components useful for signal processing and data storage, and a telemetry module for transmitting data from the sensor electronics module to, e.g., one or more display devices. Electronics can be affixed to a printed circuit board (PCB), or the like, and can take a variety of forms. For example, the electronics can take the form of an integrated circuit (IC), such as an Application- Specific Integrated Circuit (ASIC), a microcontroller, and / or a processor.

[0032] Display devices 110, 120, 130, and / or 140 are configured for displaying displayable sensor data, including analyte data, which may be transmitted by sensor electronics module 12. Each of display devices 110, 120, 130, and / or 140 may include a display such as a touchscreen display 112, 122, 132, and / or 142 for displaying sensor data to a patient and / or for receiving inputs from the patient. For example, a graphical user interface (GUI) may be presented to the patient for such purposes. In certain embodiments, the display devices may include other types of user interfaces such as a voice user interface instead of, or in addition to, a touchscreen display for communicating sensor data to the patient of the display device and / or for receiving patient inputs. In certain embodiments, one, some, or all of display devices 110, 120, 130, 140 may be configured to display or otherwise communicate the sensor information as it is communicated from sensor electronics module 12 (e.g., in a data package that is transmitted to respective display devices), without any additional prospective processing required for calibration and / or real-time display of the sensor data.

[0033] The plurality of display devices 110, 120, 130, 140 depicted in FIG. 1 may include a custom or proprietary display device, for example, display device 110, especially designed for displaying certain types of displayable sensor information associated with analyte data received from sensor electronics module 12 (e.g., a numerical value and / or an arrow, in certain embodiments). In certain embodiments, one of the plurality of display devices 110, 120, 130, 140 includes a smartphone, such as a mobile phone, based on an Android, iOS, or another operating system configured to display a graphical representation of the continuous sensor data (e.g., including current and / or historic data). In some embodiments, one of the plurality of display devices 110, 120, 130, 140 may include a home automation system display or speakers. In certain embodiments, health management system 100 further includes a medical delivery device (e.g., an insulin pump or pen). Sensor electronics module 12 may be configured totransmit sensor information and / or analyte data to medical delivery device. The medical delivery device (not shown) may be configured to administer a certain dosage of insulin or another medicament to the user based on the sensor information and / or analyte data (e.g., which may include a recommended insulin dosage) received from the sensor electronics module 12.

[0034] Server system 134 may be used to directly or indirectly collect analyte data from SS 8 and / or the plurality of display devices, for example, to perform analytics thereon, generate universal or individualized models for analyte concentration levels and profiles, provide services or feedback, including from individuals or systems remotely monitoring the analyte data, perform or assist SS 8 and the plurality of display devices with identification, authentication, etc., according to the embodiments described herein, so on. Note that, in certain embodiments, server system 134 may be representative of multiple systems or computing devices that perform the functions of server system 134 (e.g., in a distributed manner).

[0035] The term “analyte” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning), and refers without limitation to a substance or chemical constituent in a biological fluid (e.g., blood, interstitial fluid, cerebral spinal fluid, lymph fluid, urine, sweat, saliva, etc.) that can be analyzed. Analytes can include naturally occurring substances, artificial substances, metabolites, electrolytes, ions, gasses, hormones, proteins, enzymes, neurotransmitters, infectious agents, and / or reaction products. In some examples, the analyte measured by the sensing regions, devices, and methods is glucose. However, other analytes are contemplated as well, including but not limited to acarboxyprothrombin; acylcamitine; adenine phosphoribosyl transferase; adenosine deaminase; albumin; alpha-fetoprotein; amino acid profiles (arginine (Krebs cycle), histidine / urocanic acid, homocysteine, phenylalanine / tyrosine, tryptophan); andrenostenedione; antipyrine; arabinitol enantiomers; arginase; benzoylecgonine (cocaine); bilirubin, biotinidase; biopterin; c-reactive protein; carnitine; camosinase; CD4; ceruloplasmin; chenodeoxycholic acid; chloroquine; cholesterol; cholinesterase; conjugated 1-P hydroxy-cholic acid; cortisol; creatine; creatine kinase; creatine kinase MM isoenzyme; creatinine; cyclosporin A; d-penicillamine; de- ethylchloroquine; dehydroepiandrosterone sulfate; DNA (acetylator polymorphism, alcohol dehydrogenase, alpha 1 -antitrypsin, cystic fibrosis, Duchenne / Becker musculardystrophy, glucose-6-phosphate dehydrogenase, hemoglobin A, hemoglobin S, hemoglobin C, hemoglobin D, hemoglobin E, hemoglobin F, D-Punjab, beta-thalassemia, hepatitis B virus, HCMV, HIV-1, HTLV-1, Leber hereditary optic neuropathy, MCAD, RNA, PKU, Plasmodium vivax, 21 -deoxycortisol); desbutylhalofantrine; dihydropteridine reductase; diptheria / tetanus antitoxin; erythrocyte arginase; erythrocyte protoporphyrin; esterase D; fatty acids / acylglycines; free P-human chorionic gonadotropin; free erythrocyte porphyrin; free thyroxine (FT4); free tri-iodothyronine (FT3); fumarylacetoacetase; galactose / gal-1 -phosphate; galactose- 1 -phosphate uridyltransferase; gentamicin; glucose-6-phosphate dehydrogenase; glutathione; glutathione perioxidase; glycerol; glycocholic acid; glycosylated hemoglobin; halofantrine; hemoglobin variants; hexosaminidase A; human erythrocyte carbonic anhydrase I; 17-alpha-hydroxyprogesterone; hypoxanthine phosphoribosyl transferase; immunoreactive trypsin; beta-hydroxybutyrate; manganese; ketones; lactate; lead; lipoproteins ((a), B / A-l, P); lysozyme; mefloquine; netilmicin; oxygen; phenobarbitone; phenytoin; phytanic / pristanic acid; potassium, sodium, and / or other blood electrolytes; 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 pneumoniae, Myoglobin, Onchocerca volvulus, parainfluenza virus, Plasmodium falciparum, 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, HIV-1); succinylacetone; sulfadoxine; theophylline; thyrotropin (TSH); thyroxine (T4); thyroxine-binding globulin; trace elements; transferrin; UDP-galactose-4-epimerase; urea; uric acid; uroporphyrinogen I synthase; vitamin A; white blood cells; and zinc protoporphyrin. Salts, sugar, protein, fat, vitamins, and hormones naturally occurring in blood or interstitial fluids can also constitute analytes in certain examples. The analyte can be naturally present in the biological fluid, or endogenous, for example, a metabolic product, a hormone, an antigen, an antibody, and the like. Alternately, the analyte can be introduced into the body, orexogenous, for example, a contrast agent for imaging, a radioisotope, a chemical agent, a fluorocarbon-based synthetic blood, or a drug or pharmaceutical composition, including but not limited to insulin; ethanol; cannabis (marijuana, tetrahydrocannabinol, hashish); inhalants (nitrous oxide, amyl nitrite, butyl nitrite, chlorohydrocarbons, hydrocarbons); cocaine (crack 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, mescaline, peyote, psilocybin); narcotics (heroin, codeine, morphine, opium, meperidine, Percocet, Percodan, Tussionex, Fentanyl, Darvon, Talwin, Lomotil); designer drugs (analogs of fentanyl, meperidine, amphetamines, methamphetamines, and phencyclidine, for example, Ecstasy); anabolic steroids; and nicotine. The metabolic products of drugs and pharmaceutical compositions are also contemplated analytes. Analytes such as neurochemicals and other chemicals generated within the body can also be analyzed, such as, for example, ascorbic acid, uric acid, dopamine, noradrenaline, 3-methoxytyramine (3MT), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 5 -hydroxy tryptamine (5HT), 5- hydroxyindoleacetic acid (FHIAA), and histamine.

[0036] The term “ion” as used herein is a broad term, and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning), and refers without limitation to an atom or molecule with a net electric charge due to the loss or gain of one or more electrons. Ions in a biological fluid is referred to as “electrolytes.” Non-limiting examples of ions in biological fluids include sodium (Na+), potassium (K+), magnesium (Mg2+), calcium (Ca2+), hydrogen (H+), lithium (Li+), chloride (Cl-), sulfide (S2‘), sulfite (SO32’), sulfate (SO42’), phosphate (PO43'),and ammonium (NFLA). An ion is an example of an analyte.

[0037] FIG. 2 illustrates a more detailed view of health management system 100 including a display device 150 that is communicatively coupled to SS 8. In certain embodiments, display device 150 may be any one of display devices 110, 120, 130, and 140 of FIG. 1. In some embodiments, the display device 150 includes smartphone, such as a mobile phone, based on an Android, iOS, or another operating system configured to display a graphical representation of the continuous sensor data (e.g., including current and / or historic data). In some embodiments, the display device 150 may be a smartwatch or another type of device, such as an insulin pump or other type of pump.

[0038] The communication path between SS 8 and display device 150 is shown as wireless communication path 180. In certain embodiments, SS 8 and display device 150 are configured to wirelessly communicate over wireless communication path 180 using low range and / or distance wireless communication protocols. Examples of low range and / or distance wireless communication protocols include Bluetooth and Bluetooth Low Energy (BLE) protocols. In certain embodiments, other short range wireless communications may include Near Field Communications (NFC), radio frequency identification (RFID) communications, IR (infra-red) communications, optical communications. In certain embodiments, wireless communication protocols other than low range and / or distance wireless communication protocols may be used for wireless communication path 180, such as WiFi Direct. Display device 150 is also configured to connect to network 190 (e.g., local area network (LAN), wide area network (WAN), the Internet, etc.). For example, display device 150 may connect to network 190 via a wired (e.g., Ethernet) or wireless (e.g., WLAN, wireless WAN, cellular, Mesh network, personal area network (PAN) etc.) interface. Display device 150 is able to communicate with server system 134 through network 190. The communication path between display device 150 and server system 134 is shown as communication path 181 via network 190.

[0039] Note that, in certain embodiments, SS 8 may be able to independently (e.g., wirelessly) communicate with server system 134 through network 190. An independent communication path between SS 8 and server system 134 is shown as communication path 182. However, in certain other embodiments, SS 8 may not be configured with the necessary hardware / software to establish, for example, an independent wireless communication path with server system 134 through network 190. In such embodiments, SS 8 may communicate with server system 134 through display device 150. An indirect or pass-through communication path between SS 8 and server system 134 is shown as communication path 183.

[0040] In embodiments where display device 150 is a proprietary display device, such as display device 110 designed specifically for the communication of analyte data, display device 150 may not be configured with the necessary hardware / software for independently connecting to network 190. Instead, in certain such embodiments, display device 150 is configured to establish a wired or wireless communication path 184 (e.g., through a Universal System Bus (USB) connection) with computer device 103, which is configured to communicate with server system 134 through network 190. For example,computer device 103 may connect to network 190 via a wired (e.g., Ethernet) or wireless (e.g., WLAN, wireless WAN, cellular, etc.) interface. In some embodiments, the display device 150 may be capable of independently communicating with server system 134 through network 190, independent of computer device 103.

[0041] Health management system 100 additionally includes server system 134, which in turn includes server 135 that is coupled to storage 136 (e.g., one or more computer storage systems, cloud-based storage systems and / or services, etc.). In certain embodiments, server system 134 may be located or execute in a public or private cloud. In certain embodiments, server system 134 is located or executes on-premises (“on- prem”). As discussed, server system 134 is configured to receive, collect, and / or monitor information, including analyte data and related information, as well as encryption / authentication information from SS 8 and / or display device 150. Such information may include input responsive to the analyte data or input (e.g., the user’s analyte concentration measurements and other physiological / behavioral information) received in connection with an analyte monitoring or sensor application running on SS 8 or display device 150. This information may be stored in storage 136 and may be processed, such as by an analytics engine capable of performing analytics on the information. An example of an analyte sensor application that may be executable on display device 150 is analyte sensor application 121, as further described below.

[0042] In certain embodiments, server system 134 at least partially directs communications between SS 8 and display device 150, for example, for facilitating authentication therebetween. Such communications include messaging (e.g., advertisement, command, or other messaging), message delivery, and analyte data. For example, in certain embodiments, server system 134 may process and exchange messages between SS 8 and display device 150 related to frequency bands, timing of transmissions, security, alarms, and so on. In certain embodiments, server system 134 may also update information stored on SS 8 and / or display device 150. In certain embodiments, server system 134 may send / receive information to / from SS 8 and or display device 150 in realtime or sporadically. Further, in certain embodiments, server system 134 may implement cloud computing capabilities for SS 8 and / or display device 150.

[0043] FIG. 2 also illustrates the components of SS 8 in further detail. As shown, in certain embodiments, SS 8 includes analyte sensor 10 coupled to sensor electronics module 12. As shown, the sensor electronics module 12 includes one or more hardwarecomponents, such one or more processors 11, sensor measurement circuitry 13, memory 14, connectivity interface 15, and real time clock (RTC) 17. In some embodiments, the one or more hardware components of the sensor electronics module 12 may be implemented as ASIC on a printed circuit board (PCB).

[0044] As shown, sensor electronics module 12 includes the sensor measurement circuitry 13 that is coupled to analyte sensor 10 (such as a potentiostat) for processing and managing sensor data. Sensor measurement circuitry 13 may also be coupled to the one or more processors 11 of the sensor electronics module 12. In some embodiments, the one or more processors 11 may be a general-purpose or application-specific microprocessor, an ASIC, a field programmable gate array (FPGA), etc., that executes instructions to perform control, computation, input / output, etc. functions for the sensor electronics module 12. The one or more processors 11 may include a single integrated circuit, such as a micro processing device, or multiple integrated circuit devices and / or circuit boards working in cooperation to accomplish the appropriate functionality.

[0045] In some embodiments, the one or more processors 11 may be configured to sample an analog electrical signal received from the analyte sensor(s) 10 using the analog- to-digital (A / D) signal processing circuitry, such as the sensor measurement circuitry 13, at regular intervals (such as the sampling period) to generate analyte sensor count values based on the analog electrical signals received from the analyte sensor(s) 10, calibrate the analyte sensor count values based on the sensitivity profile of the analyte sensor(s) 10 to generate measured analyte concentration levels, and generate measured analyte data from the measured analyte concentration levels, generate sensor data packages that include, inter alia, the measured analyte concentration level data. The one or more processors 11 may store the measured analyte concentration level data in memory 14, and generate the sensor data packages at regular intervals (such as the transmission period) for transmission to the display device 150. The one or more processors 11 may also add additional data to the sensor data packages, such as supplemental sensor information that includes a sensor identifier, a sensor status, temperatures that correspond to the measured analyte data, etc. The sensor data packages are then wirelessly transmitted over a wireless connection to the display device 150. In certain embodiments, the wireless connection is a Bluetooth or Bluetooth Low Energy (BLE) connection. In such embodiments, the sensor data packages are transmitted in the form of Bluetooth or BLE data packets to the display device 150.

[0046] In some embodiments, the one or more processors 11 may perform part or all of the functions of the sensor measurement circuitry 13 for obtaining and processing sensor measurement values from analyte sensor 10. The one or more processors 11 may also be coupled to the memory 14 and the RTC 17 for storing and tracking sensor data. In addition, the one or more processors 11 may be further coupled to the connectivity interface 15, which includes a radio unit or transceiver (TRX) 16 for sending sensor data (e.g., measured analyte concentration levels) and receiving requests and commands from an external device, such as display device 150. As used herein, the term transceiver generally refers to a device or a collection of devices that enable SS 8 to (e.g., wirelessly) transmit and receive data. It is contemplated that, in some embodiments, the sensor measurement circuitry 13 may carry out all the functions of the one or more processors 11 or vice versa.

[0047] Transceiver 16 may be configured with the necessary hardware and wireless communications protocols for enabling wireless communications between SS 8 and other devices, such as display device 150 and / or server system 134. For example, as described above, transceiver 16 may be configured with the necessary hardware and communication protocols to establish a Bluetooth or BLE connection with display device 150. As one of ordinary skill in the art appreciates, in such an example, the necessary hardware may include a Bluetooth or BLE security manager and / or other Bluetooth or BLE related hardware / software modules configured for Bluetooth or BLE communications standards. In some embodiments where SS 8 is configured to establish an independent communication path with server system 134, transceiver 16 may be configured with the necessary hardware and communication protocols (e.g., long range wireless cellular communication protocol, such as, GSM, CDMA, LTE, VoLTE, 3G, 4G, 5G communication protocols) for establishing a wireless connection to network 190 to connect with server system 134. As discussed elsewhere, other short range protocols, may also be used for communication between display device 150 and a SS 8 such as NFC, RFID, etc.

[0048] FIG. 2 similarly illustrates the components of display device 150 in further detail. As shown, display device 150 includes connectivity interface 128, one or more processors 126, one or more memories 127, a real time clock (RTC) 163, a display 125 for presenting a graphical user interface (GUI), and a storage 123. Abus (not shown here) may be used to interconnect the various elements of display device 150 and transferdata between these elements. Connectivity interface 128 includes a transceiver (TRX) 129 used for receiving sensor data (e.g., measured analyte concentration levels) from SS 8 and for sending requests, instructions, and / or data to SS 8 as well as server system 134. Transceiver 129 is coupled to other elements of display device 150 via connectivity interface 128 and / or the bus. Transceiver 129 may include multiple transceiver modules operable on different wireless standards. For example, transceiver 129 may be configured with one or more communication protocols, such as wireless communication protocol(s) for establishing a wireless communication path with network 190 and / or low range wireless communication protocol(s) (e.g., Bluetooth or BLE) for establishing a wireless communication path 180 with SS 8. Additionally, connectivity interface 128 may in some cases include additional components for controlling radio and / or wired connections, such as baseband and / or Ethernet modems, audio / video codecs, and so on.

[0049] In some embodiments, when a standardized communication protocol is used between display device 150 and SS 8, commercially available transceiver circuits may be utilized that incorporate processing circuitry to handle low level data communication functions such as the management of data encoding, transmission frequencies, handshake protocols, security, and the like. In such embodiments, the one or more processors 126 of display device 150 and / or the one or more processors 11 of SS 8 may not need to manage these activities, but instead provide desired data values for transmission, and manage high level functions such as power up or down, set a rate at which messages are transmitted, and the like. Instructions and data values for performing these high level functions can be provided to the transceiver circuits via a data bus and transfer protocol established by the manufacturer of transceivers 129 and 16. However, in embodiments where a standardized communication protocol is not used between transceivers 129 and 16 (e.g., when non- standardized or modified protocols are used), the one or more processors 126 and 11 may be configured to execute instructions associated with proprietary communications protocols (e.g., one or more of the communications protocols described herein) to control and manage their respective transceivers. In addition, when non-standardized or modified protocols are used, customized circuitries may be used to service such protocols.

[0050] The one or more processors 126 may include processor sub-modules, including, by way of example, an applications processor that interfaces with and / or controls other elements of display device 150 (e.g., connectivity interface 128, analytesensor application 121 (hereinafter “sensor application 121”), display 125, RTC 163, one or more memories 127, storage 123, etc.). In certain embodiments, the one or more processors 126 is configured to perform functions related to device management, such as, for example, managing lists of available or previously paired devices, information related to network conditions (e.g., link quality and the like), information related to the timing, type, and / or structure of messaging exchanged between SS 8 and display device 150, and so on. The one or more processors 126 may further be configured to receive and process user input, such as, for example, a user's biometric information, such as the user’s finger print (e.g., to authorize the user's access to data or to be used for authorization / encryption of data, including analyte data), as well as analyte data.

[0051] The one or more processors 126 may include and / or be coupled to circuitry such as logic circuits, memory, a battery and power circuitry, and other circuitry drivers for periphery components and audio components. The one or more processors 126 and any sub-processors thereof may include logic circuits for receiving, processing, and / or storing data received and / or input to display device 150, and data to be transmitted or delivered by display device 150. As described above, the one or more processors 126 may be coupled by a bus to display 125, connectivity interface 128, storage 123, etc. Hence, the one or more processors 126 may receive and process electrical signals generated by these respective elements and thus perform various functions. By way of example, the one or more processors 126 may access stored content from storage 123 and one or more memories 127 at the direction of analyte sensor application 121, and process the stored content to be displayed by display 125. Additionally, the one or more processors 126 may process the stored content for transmission via connectivity interface 128 to SS 8 and / or server system 134. Display device 150 may include other peripheral components not shown in detail in FIG. 2.

[0052] In certain embodiments, the one or more memories 127 may include volatile memory, such as random access memory (RAM) for storing data and / or instructions for software programs and applications, such as analyte sensor application 121. Display 125 presents a GUI associated with operating system 162 and / or analyte sensor application 121. In various embodiments, a user may interact with analyte sensor application 121 via a corresponding GUI presented on display 125. By way of example, display 125 may be a touchscreen display that accepts touch input. Analyte sensor application 121 may process and / or present analyte -related data received by display device 150 and presentsuch data via display 125. Additionally, analyte sensor application 121 may be used to obtain, access, display, control, and / or interface with analyte data and related messaging and processes associated with SS 8 (e.g., and / or any other medical device (e.g., insulin pump or pen) that are communicatively coupled with display device 150), as is described in further detail herein.

[0053] Storage 123 may be a non-volatile storage for storing software programs, instructions, data, etc. For example, storage 123 may store analyte sensor application 121 that, when executed using the one or more processors 126, for example, receives input (e.g., by a conventional hard / soft key or a touch screen, voice detection, or other input mechanism), and allows a user to interact with the analyte data and related content via display 125. In various embodiments, storage 123 may also store user input data and / or other data collected by display device 150 (e.g., input from other users gathered via analyte sensor application 121). Storage 123 may further be used to store volumes of analyte data received from SS 8 (or any other medical data received from other medical devices (e.g., insulin pump, pen, etc.) for later retrieval and use, e.g., for determining trends and triggering alerts.

[0054] As described above, SS 8, in certain embodiments, gathers analyte data (e.g., measured analyte concentration levels) from analyte sensor 10 and transmits the same or a modified version of the collected data to display device 150. Data points regarding analyte values may be gathered and transmitted over the life of analyte sensor 10 (e.g., in the range of 1 to 30 days or more). New measurements may be transmitted often enough to adequately monitor analyte concentration levels. In certain embodiments, rather than having the transmission and receiving circuitry of each of SS 8 and display device 150 continuously communicate, SS 8 and display device 150 may regularly and / or periodically establish a communication channel among each other. Thus, in such embodiments, SS 8 may, for example, communicate with display device 150 at predetermined time intervals. The duration of the predetermined time interval can be selected to be long enough so that SS 8 does not consume too much power by transmitting data more frequently than needed, yet frequent enough to provide substantially real-time sensor information (e.g., measured glucose values or analyte data) to display device 150 for output (e.g., via display 125) to the user. While the predetermined time interval is every five minutes in some embodiments, it is appreciated that this time interval can be varied to be any desired length of time. In other embodiments, transceivers 129 and 16may be continuously communicating. For example, in certain embodiments, transceivers 129 and 16 may establish a session or connection there between and continue to communicate together until the connection is lost.

[0055] Analyte sensor application 121 may be downloaded, installed, and initially configured / setup on display device 150. For example, display device 150 may obtain analyte sensor application 121 from server system 134, or from another source, such as an application store or the like, via a network, e.g., network 190. Following installation and setup, analyte sensor application 121 may be configured to access, process, and / or interface with analyte data (e.g., whether stored on server system 134, locally from storage 123, from SS 8, or any other medical device). By way of example, analyte sensor application 121 may present a menu that includes various controls or commands that may be executed in connection with the operation of SS 8, display device 150, one or more other display devices (e.g., display device 110, 130, 140, etc.), and / or one or more other partner devices, such as an insulin pump. For example, analyte sensor application 121 may be used to interface with or control other display and / or partner devices, for example, to deliver or make available thereto analyte data, including for example by receiving / sending analyte data directly to the other display and / or partner device and / or by sending an instruction for SS 8 and the other display and / or partner device to be connected.

[0056] In certain embodiments, after downloading analyte sensor application 121, as one of the initial steps, the user may be directed by analyte sensor application 121 to establish a secure wireless connection between the display device 150 to the SS 8 of the user, which the user may have already placed on their body. A wireless communication path 180 between display device 150 and SS 8 allows SS 8 to transmit analyte measurements to display device 150 and for the two devices to engage in any of the other interactions described above.

[0057] FIG. 3A illustrates a perspective view of the SS 8 described with respect to FIGS. 1 and 2. As shown, the sensor electronics module 12 of the SS 8 may include an outer housing with a first, top portion 392 and a second, bottom portion 394. In embodiments, the outer housing may include a clamshell design.

[0058] As shown in FIG. 3A, the outer housing may feature a generally oblong shape. The outer housing may further include aperture 396 disposed substantially througha center portion of outer housing and adapted for analyte sensor(s) 10 and needle insertion through a bottom of SS 8. In embodiments, aperture 396 may be a channel or elongated slot. SS 8 may further include an adhesive patch 326 configured to secure SS 8 to epidermis of a user (e.g., user 50 described with respect to FIG. 1). In embodiments, adhesive patch 326 may include an adhesive suitable for skin adhesion, for example a pressure sensitive adhesive (e.g., acrylic, rubber-based, or other suitable type) bonded to a carrier substrate (e.g., spun lace polyester, polyurethane film, or other suitable type) for skin attachment, though any suitable type of adhesive is also contemplated. As shown, adhesive patch 326 may feature an aperture 398 aligned with aperture 396 such that analyte sensor(s) 10 may pass through a bottom of SS 8 and through adhesive patch 326.

[0059] FIG. 3B illustrates a bottom perspective view of SS 8 of FIG. 3A. FIG. 3B further illustrates aperture 396 disposed substantially in a center portion of a bottom of SS 8, and aperture 398, both adapted for analyte sensor(s) 10 and needle insertion.

[0060] FIG. 3C illustrates a cross-sectional view of SS 8 of FIGs. 3A and 3B. FIG. 3C illustrates the first, top portion 392 and the second, bottom portion 394 of the outer housing, adhesive patch 326, aperture 396 in the center portion of SS 8, aperture 398 in the center portion of adhesive patch 326, and analyte sensor(s) 10 passing through aperture 396. As sensor electronics module 12, previously described in connection with FIGS. 1 and 2, may further include a PCB 304 for communicatively coupling one or more hardware components of the sensor electronics module 12 of the SS 8, such as the analyte sensor(s) 10, the one or more processors 11, the sensor measurement circuitry 13, the memory 14, the connectivity interface 15, and the RTC 17. Additionally, as shown, the sensor electronics module 12 may include a battery 302, which may be electrically coupled to the PCB 304 and configured to provide power to the one or more hardware components of the SS.

[0061] Further, as shown, the analyte sensor(s) 10 includes one or more electrodes configured for sensing or measuring analyte concentration levels of a user (e.g., user 50). For example, as shown, the analyte sensor(s) 10 includes a working electrode 337 and a reference electrode 339. In some embodiments, while not shown in FIG. 3C, the working electrode 337 and reference electrode 339 may be electrically coupled to one or more other hardware components of the sensor electronics module 12 (e.g., the one or more processors 11 and / or the sensor measurement circuitry 13) via respective input pins on the PCB 304.

[0062] In some embodiments, the working electrode 337 may be coated, covered, treated, embedded, etc., with one or more chemical molecules that react with a particular analyte of a user and produce a measurable electrical analog signal proportional to a concentration of that particular analyte. The reference electrode 339 may be used to provide a stable, known potential or voltage, against which a potential of the working electrode 337 may be measured, ensuring precise control and accurate measurement of the concentration level of the analyte within the user. Additional details regarding working electrodes and reference electrodes may be found in one or more of (1) U.S. Non-Provisional Patent Application Serial No. 18 / 241,658 filed on September 1, 2023 and entitled, “DEVICES AND METHODS FOR MEASURING A CONCENTRATION OF A TARGET ANALYTE IN A BIOLOGICAL FLUID IN VIVO,” (2) U.S. Provisional Patent Application Serial No. 63 / 268,417 filed on February 23, 2022 and entitled, “SENSING SYSTEMS AND METHODS FOR PROVIDING DECISION SUPPORT AROUND KIDNEY DISEASE,” (3) U.S. Provisional Patent Application Serial No. 63 / 365,702 filed on June 1, 2022 and entitled, “DIAGNOSIS AND DECISION SUPPORT FOR DIABETES IN PATIENTS WITH KIDNEY DISEASE,” (4) U.S. Provisional Patent Application Serial No. 63 / 376,673 filed on September 22, 2022 and entitled, “SENSING SYSTEMS AND METHODS FOR DIAGNOSING KIDNEY DISEASE,” (5) U.S. Provisional Patent Application Serial No. 63 / 387,078 filed on December 12, 2022 and entitled, “DECISION SUPPORT TECHNIQUES USING PHYSIOLOGICAL PROFILES,” (6) U.S. Provisional Patent Application Serial No. 63 / 377,332 filed on September 27, 2022 and entitled, “SENSING SYSTEMS AND METHODS FOR PROVIDING DECISION SUPPORT AROUND KIDNEY DISEASE AND / OR DIABETES,” (7) U.S. Non-Provisional Patent Application Serial No. 18 / 173,753 filed on February 23, 2023 and entitled, “SENSING SYSTEMS AND METHODS FOR PROVIDING DECISION SUPPORT AROUND KIDNEY HEALTH and / or Diabetes,” (8) U.S. Non-Provisional Patent Application Serial No. 18 / 326,985 filed on May 31, 2023 and entitled, “SYSTEMS AND METHODS FOR MONITORING, DIAGNOSIS, AND DECISION SUPPORT FOR DIABETES IN PATIENTS WITH KIDNEY DISEASE,” (9) U.S. Non-Provisional Patent Application Serial No. 18 / 327,012 filed on May 31, 2023 and entitled, “SENSING SYSTEMS AND METHODS FOR DIAGNOSING KIDNEY DISEASE,” and (9) U.S. Non-Provisional Patent Application Serial No. 18 / 327,014 filed on May 31, 2023 and entitled, “SYSTEMS AND METHODS FOR OPTIMIZING TREATMENT USING PHYSIOLOGICAL PROFILES,” all ofwhich are incorporated herein by reference in their entireties.

[0063] As used herein, "noise" refers to any undesired electrical signal, fluctuation, or interference that is superimposed upon or coupled into the signal path of an analyte sensor circuit, and which may impair the accurate detection, measurement, or interpretation of an analyte-related signal. Such noise may originate from intrinsic sources, including thermal noise, flicker noise (1 / f noise), or leakage currents within sensor elements, amplifiers, or analog front-end circuitry. Noise may also arise from extrinsic sources, such as electromagnetic interference (EMI), radio frequency interference (RFI), capacitive or inductive coupling from adjacent circuitry, or power supply instability. The noise may further include environmental noise that may be random (e.g., a strong light shining on the analyte sensor system, nearby electronic equipment turning on, a phone or radio frequency (RF) signal coming too close to the analyte sensor system, etc.) and non-random noise (e.g., neighboring power lines carrying 50 / 60 Hertz alternating current (AC) signals). In the context of analyte sensing, noise may adversely affect signal-to-noise ratio (SNR), limit of detection (ROD), baseline stability, or calibration accuracy, thereby reducing the reliability or sensitivity of the sensor output. The term encompasses both random and deterministic disturbances across the frequency spectrum that interfere with the faithful transduction, amplification, or digitization of signals representative of analyte concentration or presence.Aspects Related to a Wearable Device for Potentiometric-Based Analyte Measurements

[0064] The continuous measurement of analytes (e.g., sodium, potassium, chloride, etc.) within individuals has remained a major challenge in medicine. The ability to measure analytes, in real time, would facilitate improved outcomes for those individuals with acute and chronic disease in disparate fields such as nephrology, hepatology, and cardiology. As an example, dialysis prolongs millions of lives for those with end-stage renal disease but results in substantial healthcare burden due to the need for frequent blood sampling to assess electrolyte balance or level(s). Indeed, bedside and point-of-care instrumentation for the assessment of electrolytes in whole blood samples have been commercially available for the past five decades. However, this point-of-care instrumentation only provides a single snapshot-in-time measurement, which has limited clinical utility.

[0065] Accordingly, there is a need to provide instrumentation that is capable ofmore frequent or continuous analyte measurements. Such instrumentation may include, for example, a wearable device, such as the SS 8 described with respect to FIGS. 1, 2, 3A, 3B, and 3C, which may be configured for continuous analyte sensing. In some cases, this continuous analyte sensing may be enabled through the use of a potentiometric analyte sensor configured to perform potentiometric -based analyte measurements, such as the analyte sensor(s) 10 depicted and described with respect to FIGS. 1, 2, 3A, 3B, and 3C.

[0066] In some cases, to ensure accuracy of the potentiometric -based analyte measurements, the potentiometric -based analyte measurements may be performed by the analyte sensor based on an open circuit potential (e.g., voltage) in which the analyte sensor has low output current and a very high output impedance. To perform the measurements, the wearable device receives or accesses a first signal on a working electrode (WE) of the analyte sensor (e.g., working electrode 337 described with respect to FIG. 3C) and a second signal on a reference electrode (RE) (e.g., reference electrode 339 described with respect to FIG. 3C) of the analyte sensor. Both signals may be input into a differential amplifier of the wearable device configured to output an output signal having an output voltage representing a differential between the first signal from the WE and the second signal from the RE. The output signal, which may represent an analyte concentration level of a user of the wearable device, may then be filtered by a low pass filter (LPF) to remove any high frequency noises before being input into an analog-to- digital converter (ADC) of the wearable device configured to convert the output signal to a digital signal. The digital signal may then be processed by one or more processors of the wearable device, which may be configured to convert the digital signal into an estimated analyte value, representing the analyte concentration level of the user. This estimated analyte value may then be sent by the wearable device to a display device for display to the user (e.g., via a wireless connection or transmission, for instance, Bluetooth).

[0067] A major challenge associated with performing potentiometric -based analyte measurements is leakage current and noise associated with a PCB (e.g., PCB 304) of the wearable device, each of which may significantly impact an accuracy of the potentiometric-based analyte measurements performed by the wearable device. Accordingly, as will be described in further detail below, to improve the accuracy of analyte measurements performed by the wearable device, aspects of the present disclosureprovide techniques for reducing leakage current and noise associated with the wearable device.Example Circuits for Potentiometric-Based Analyte Measurements

[0068] FIGS. 4 and 5 illustrate example ASICs for a wearable device, such as the SS 8, that may be used to perform high-impedance potentiometric-based measurements of analyte concentration levels of a user of the wearable device. In some embodiments the example amplifier circuits may be examples of the sensor measurement circuitry 13 of the SS 8 described with respect to FIG. 2. In some embodiments, the amplifier circuits illustrated in FIGS. 4 and 5 (e.g., the sensor measurement circuitry 13) may be part of an analog front end (AFE) of the SS 8.

[0069] For example, FIG. 4 illustrates a first example ASIC 400 having a high common mode rejection ratio, which may allow for reduced leakage current(s) and noise. As shown, the ASIC 400 may be disposed on a PCB 499 of the wearable device. Further, as shown, the ASIC 400 includes a plurality of pins for receiving signals from an analyte sensor, such as the analyte sensor 10 described with respect to FIG. 2. For example, as shown, the ASIC 400 includes a working electrode (WE) pin 402 to which the working electrode 337 of the analyte sensor 10 may be coupled via a first electrical trace 428. Additionally, the ASIC 400 may include a reference electrode (RE) pin 404 to which the reference electrode 339 of the analyte sensor 10 may be coupled via a second electrical trace 430.

[0070] As shown, the ASIC 400 of FIG. 4 includes three operational amplifiers, forming an instrumentation amplifier 490, which may be configured to amplify signals received from the analyte sensor 10. For example, as shown, the ASIC 400 includes a first operational amplifier 406 configured to receive a first input signal 401(e.g., VWE) from the working electrode 337 of the analyte sensor 10 via the first electrical trace 428 disposed on the PCB 499 to which the working electrode pin 402 is coupled. The first input signal 401 (e.g., VWE) may have a first noise component which may be caused by one or more aspects including, but not limited to, environmental noise, as described herein, or one or more leakage currents (e.g., from components of PCB 499). Additionally, as shown, the ASIC 400 includes a second operational amplifier 408 configured to receive a second input signal 403 (e.g., VRE) from the reference electrode 339 of the analyte sensor via the second electrical trace 430 disposed on the PCB 499 towhich the RE pin 404 is coupled. The first operational amplifier 406 and the second operational amplifier 408 form an input buffering stage 492 of the ASIC 400 configured to allow for configurations of variable gains. The first operational amplifier 406 may output a first output signal 410 based on the first input signal 401 received from the working electrode 337 of the analyte sensor 10. Similarly, the second operational amplifier 408 may output a second output signal at 412 based on the second input signal 403 received from the reference electrode 339 of the analyte sensor 10.

[0071] Thereafter, the first output signal 410 from the first operational amplifier 406 and the second output signal 412 from the second operational amplifier 408 may then be input into a third operational amplifier 414 in a differential amplification stage 494 of the ASIC 400. The third operational amplifier 414 may be a differential amplifier that is configured to output a third output signal 413 having an output voltage (Vout) representing a differential voltage between a first voltage of the first signal (e.g., VWE) received from the working electrode 337 of the analyte sensor 10 and a second voltage of the second signal (e.g., VRE) received from the reference electrode 339 of the analyte sensor 10 (e.g., VWE-VRE). In some embodiments, the third output signal 413 may be representative of an analyte concentration level of a user. In some embodiments, third output signal 413 may have a second noise component which is reduced or lower than the first noise level (e.g., of first input signal 401 (e.g., VWE)). Thereafter, the third output signal 413 may be provided to a low pass filter (LPF) 416. For example, the third output signal 413 may comprise a slow varying direct current (DC) signal, which may be prone to noise, such as noise introduced by neighboring power lines carrying 50 / 60 Hertz alternating current (AC) signals or other noises. As such, the EPF 416 may be configured to filter out this noise, improving a signal to noise ratio (SNR) of the third output signal 413. In some embodiments, EPF 416 includes a resistor (e.g., of 300 kilo-ohms (kQ) or within the range of 10 kilo-ohms (kQ) - 4 mega-ohms (MQ)) and a capacitor Cl (e.g., with a capacitance of 0.1 uF (microfarads) or in the range of 0.0047uF - 0.47uF). The output of EPF 416 may also have a third noise component which is reduced or lower than the first noise level (e.g., of first input signal 401 (e.g., VWE)). The third noise component of the output of EPF 416 may also be lower than a second noise component of third output signal 413. Thereafter, the filtered third output signal 413 may be provided to an analog-to-digital converter (ADC) 418 to be converted to a digital signal before being provided to one or more processors, such as the one or more processors 11 of the SS 8, for further processing.After or as part of the further processing, the digital signal may be converted to an analyte value which is communicated by analyte sensor 10 (e.g., via Bluetooth) to a display device (e.g., display device 120).

[0072] Additionally, as shown in FIG. 4, the ASIC 400 includes a fourth operational amplifier 424, forming a guard driver, which may be used to reduce noise on a PCB of the wearable device to which the ASIC 400 is coupled. For example, the fourth operational amplifier 424 may receive and buffer the third output signal 413. Thereafter, the fourth operational amplifier 424 may output the buffered third output signal 413 to a third electrical trace 426 on the PCB 499 that is positioned adjacent to, but does not touch, the first electrical trace 428 on the PCB 499 on which the first input signal 401 is received from the working electrode 337. In some embodiments, the third electrical trace 426 may comprise one or more guard bands that surround the first electrical trace 428, as explained further below. In some cases, the buffered third output signal 413 that is output to the third electrical trace 426 may have a same potential (e.g., voltage level) as, or substantially similar to that of, the first input signal 401 received on the first electrical trace 428. In some cases, outputting the buffered third output signal 413 to the third electrical trace 426 may help to prevent leakage current from flowing into or out of the first electrical trace 428 carrying the first input signal 401 from the working electrode 337. The first input signal 401 (e.g., VWE) may have a reduced noise level because of the potential or voltage of third electrical trace 426 (e.g., due to reduced leakage current). For example, the one or more guard bands may create a Faraday cage-like effect, aiming to neutralize external charge or otherwise ensure that conductors adjacent to first electrical trace 428 are maintained at equivalent or substantially equivalent potentials to eliminate voltage gradients, which would otherwise drive the transfer of electric charge in the form of leakage currents. The third output signal 413 may thus have a reduced or lower noise component than first input signal 401 as a result of the third electrical trace 426.

[0073] As shown in FIG. 4, the ASIC 400 includes one or more resistors. Instrumentation amplifier 490 may include resistors Ri-Re. In some embodiments, input buffering stage 492 includes resistors Rs and Re, differential amplification stage 494 includes resistors Ri and R2 and resistors R3 and R4. Resistors Ri is coupled to the output of the second operational amplifier 408 and the inverting input of the third operational amplifier 414 (and resistor R2). Resistor R3 is coupled to output of the first operational amplifier 406 and the non-inverting input of the third operational amplifier 414 (andresistor R4). Resistor R2 is coupled to the inventing input of the third operational amplifier 414, resistor Ri, and the output of the third operational amplifier 414. Resistor R4 is coupled to the non-inventing input of the third operational amplifier 414, resistor R3, RE pin 404, and switch 422. Resistor R5 is coupled to the inventing input of the second operational amplifier 408, resistor Ri, and the output of the second operational amplifier 408. Resistor R6 is coupled to the inventing input of the first operational amplifier 406, resistor R3, and the output of the first operational amplifier 406. Resistors Ri-Re function to set the gains of the operational amplifiers that make up the instrumentation amplifier 490. In some embodiments, each resistor may have a same or substantially similar resistance (e.g., 50 kilo-ohms (kQ), or in the range of 10 kilo-ohms (kQ) to 10 megaohms (MQ)), resulting in the input buffering stage 492 and the differential amplification stage 494 having a unity gain. The unity gain enables the third output signal 413 to be used to drive the third electrical trace 426 (via fourth operational amplifier 424) with a voltage that is the same or substantially similar voltage to first input signal 401 thereby reducing noise on PCB 499 and a noise component of third output signal 413 (e.g., by reducing leakage current from other components of PCB 499).

[0074] FIG. 5 illustrates a simplified example ASIC 500 using only a single operational amplifier, which may allow for reduced leakage currents and noise. The usage of a single operational amplifier may consume power as there are less operational amplifiers. Additionally, the single operational amplifier embodiment of FIG. 5 may allow for reduced implementation costs and complexity and may allow the ASIC 500 to use less real estate on the PCB 599 of the wearable device. Additionally, as shown, the ASIC 500 includes a plurality of pins for receiving signals from an analyte sensor, such as the analyte sensor 10 described with respect to FIG. 2. For example, as shown, the ASIC 500 includes a working electrode (WE) pin 502 to which a working electrode of the analyte sensor 10 (e.g., working electrode 337) may be coupled. Additionally, the ASIC 500 may include a reference electrode (RE) pin 504 to which a reference electrode of the analyte sensor 10 (e.g., reference electrode 339) may be coupled. The first input signal 501 (e.g., VWE) may have a first noise component or level which may be caused by one or more aspects including, but not limited to, environmental noise, as described herein, or one or more leakage currents (e.g., from components of PCB 599).

[0075] As shown, the ASIC 500 of FIG. 5 includes a single operational amplifier 506 configured to receive a first input signal 501 from the working electrode 337 of theanalyte sensor 10, for example, via the working electrode pin 502. In some embodiments, the operational amplifier 506 may then be configured to output an output signal 509 representative of an analyte concentration level of a user. In some embodiments, output signal 509 may have a second noise component or level which is reduced or lower than the first noise level (e.g., of first input signal 501 (e.g., VWE)). The output signal may then be filtered by an LPF 508. In some embodiments, LPF 508 includes a resistor (e.g., of 300 kilo-ohms (kQ) or within the range of 10 kilo-ohms (kQ) - 4 mega-ohms (MQ)) and a capacitor C2 (e.g., with a capacitance of 0.1 uF (microfarads) or in the range of 0.0047uF - 0.47uF) which in combination function as a low pass filter. The output of LPF 508 may also have a third noise component which is reduced or lower than the first noise level (e.g., of first input signal 501 (e.g., VWE)). The third noise component of the output of LPF 508 may also be lower than a second noise component of output signal 509. The filtered output signal may then be provided to an ADC 510 to be converted to a digital signal before being provided to one or more processors, such as the one or more processors 11 of the SS 8, for further processing. After or as part of the further processing, the digital signal may be converted to an analyte value which is communicated by analyte sensor 10 (e.g., via Bluetooth) to a display device (e.g., display device 120).

[0076] In some embodiments, the output signal output by the operational amplifier 506 may be based solely on the first input signal 501 received from the working electrode 337. Alternatively, in some embodiments, the output signal output by the operational amplifier 506 may be additionally based on a voltage offset shown at 520 that may be applied or added to the first input signal 501 (e.g., via selective coupling with switch 522, described in further detail below).

[0077] Additionally, while not shown in FIG. 5, it should be appreciated that the ASIC 500 may also include another operational amplifier, forming a guard driver, which may be used to reduce noises on the PCB 599, similar to the fourth operational amplifier 424 described with respect to FIG. 4. For example, the additional operational amplifier may receive and buffer the output signal 509. Thereafter, the additional operational amplifier may output the buffered output signal 509 to a first electrical trace that is positioned adjacent to, but does not touch, a second electrical trace on the PCB 599 on which the first input signal 501 is received from the working electrode 337. In some embodiments, the first electrical trace may comprise one or more guard bands that surround the second electrical trace, as explained further below. In some cases, thebuffered output signal 509 that is output to the first electrical trace may have a same or substantially similar potential (e.g., voltage level) as, or very close to that of, the first input signal 501 received on the second electrical trace. In some cases, outputting the buffered output signal 509 to the first electrical trace may help to prevent leakage current from flowing into or out of the second electrical trace carrying the first input signal 501 from the working electrode 337.

[0078] As noted above, the ASICs 400 and 500 may be used to perform potentiometric-based analyte measurements of a user of a wearable device. However, an accuracy of these potentiometric-based analyte measurements may be susceptible to leakage current and noise associated with a PCB (e.g., PCB 304) of the wearable device (e.g., on which the ASIC 400 and / or ASIC 500 are disposed). Accordingly, as will be described in greater detail below, to improve the accuracy of the potentiometric-based analyte measurements, the ASICs 400 and 500 may include additional features configured to reduce leakage currents and noise.Analyte Senor Calibration

[0079] Calibration of the potentiometric-based analyte sensor(s) 10 may be helpful to ensure accuracy and reliability in measuring analyte concentration levels of a user. For example, calibration may compensate for drift or other effects due to the materials of the PCB and other components of the wearable device and helps to ensures that the wearable device’s measurements accurately reflect the true concentration level of the analyte. More specifically, for example, without calibration, an output of the analyte sensor(s) 10 may drift or deviate from an actual value of the analyte concentration, leading to incorrect readings.

[0080] In some embodiments, calibration may involve inputting a first known input voltage (Vii) into the working electrode 337 of the analyte sensor(s) 10 and measuring a first output voltage (Voi) (e.g., a voltage at the junction between the resistor and the capacitor Cl of LPF 416 coupled to the input of the ADC 418 or the output of ADC 418) of the working electrode 337. In some embodiments, the first output voltage may be sampled a number of times and averaged. A second known input voltage (V12) may then be input into the working electrode 337 of the analyte sensor(s) 10 and one or more samples of a second output voltage (V02) of the working electrode 337 may be measured and averaged. A third known input voltage (Via) may then be input into the workingelectrode 337 of the analyte sensor(s) 10 and one or more samples of a third output voltage (V03) of the working electrode 337 may be measured and averaged.

[0081] Thereafter, linear regression may be performed based on the linear regression model y = mx + c to determine an equation of a line represented by the known input voltages and corresponding output voltages, where x equals the known input voltages (e.g., Vii, Vi2, and Via), y equals the measured output voltages (e.g., V01, V02, and V03 ), m is the slope of a line represented by the known input voltages and measured output voltages, and c is the y- intercept of the line represented by the known input voltages and measured output voltages. Accordingly, given the known input voltages (e.g., Vii, Vi2, and Via) and the measured output voltages (e.g., V01, V02, and V03), the slope m and y- intercept may be determined. Thereafter, based on the slope m and y-intercept, a gain and offset associated with the working electrode may be determined, where the gain (G) is equal to 1 / m and the offset is equal to -c. It should be appreciated that, while the techniques described above involve the use of three input voltages and three output voltages, these techniques may be equally applicable to the use of two input voltages (e.g., Vii and Vi2) and two output voltages (e.g., V01 and V02) or more than three input voltages and three output voltages.

[0082] The gain and offset may then be stored in memory of the wearable device (e.g., SS 8) and used to scale and adjust raw analyte measurements performed by the analyte sensor(s) 10. Scaling and adjusting the raw analyte measurements performed by the analyte sensor(s) 10 may allow for the wearable device to account for any deviations associated with the working electrode and for the wearable device to determine a true value of a measured analyte. For example, a raw analyte measurement performed by the analyte sensor(s) 10 (Ameas_raw) may first be adjusted based on the offset (c) or (-c) and then the adjusted analyte measurement may be scaled based on the gain (G) to determine the true value of the measured analyte (Ameas) according to Ameas= (Ameas raw— c) * GVoltage Offset for Improved SNR

[0083] Due to high-impedance characteristics of the potentiometric -based analyte sensor(s) 10, the potentiometric-based analyte measurements performed by the analyte sensor(s) 10 may be sensitive to environmental noise. If this noise is unable to be filtered out by an analog front end (AFE) of the wearable device, an integrity of thesepotentiometric-based analyte measurements may be compromised. For example, as shown at 417 in FIG. 4 and at 512 in FIG. 5, the reference electrode 339 of the analyte sensor(s) 10 may be tied to ground, which may affect potentiometric-based analyte measurements taken by the analyte sensor(s) 10. For example, the reference electrode 339 may be fixed at ground while the working electrode 337 may fluctuate up and down due to environmental noise, meaning that the third output signal 413 of the ASIC 400 and the output signal 509 of the ASIC 500 (e.g., representing a differential voltage between the first input signal 401, 501 received from the working electrode 337 and the second input signal 403, 503 received from the reference electrode) does not simply represent a measured analyte, but may also partially include noise, which may compromise the accuracy of the measured analyte.

[0084] For example, with reference to FIG. 4, in some cases, the first input signal 401 received from the working electrode 337 has a voltage (VWE) of about 500 millivolts. Additionally, in some cases, another 100 millivolts of noise (Vnoise) is added to first input signal 401 received from the working electrode 337 as well as that another 100 millivolts of noise (Vnoise) is added to the second input signal 403 received from the working electrode 337. In some cases, due to the randomness of this noise (Vnoise), this 100 millivolts of added noise may be a positive voltage while in some cases the 100 millivolts of added noise (Vnoise) may be a negative voltage, causing the first input signal 401 received on the working electrode 337 to fluctuate between 600 millivolts (e.g., 500 millivolts + 100 millivolts from noise) and 400 millivolts (e.g., 500 millivolts - 100 millivolts from noise). This fluctuation may cause issues in determining a true value of the first input signal 401 received on the working electrode 337 when the reference electrode 339 is fixed at ground.

[0085] For example, as noted above, when the added noise (Vnoise) is a positive voltage, this may result in the signal received on the working electrode 337 having a voltage of about 600 millivolts. Similarly, when a signal received on the reference electrode 339 is about 0 millivolts, the positive voltage of the added noise may result in this signal having a voltage of 100 millivolts. Accordingly, for positive noise voltages, a true value of the first signal received on the working electrode 337 may be determined by taking the difference between the voltage of the first signal received on the working electrode 337, including the positive voltage of the added noise, and the voltage of the second input signal 403 received on the reference electrode 339, including the positivevoltage of the added noise. In other words, the 100 millivolts from the second input signal 403 received on the reference electrode 339 (e.g., including the 100 millivolts from the added noise) may be subtracted from the 600 millivolts of the first input signal 401 received on the working electrode 337 to arrive at 500 millivolts, which is the true value of the first input signal 401 received on the working electrode 337.

[0086] However, when the voltage of the added noise is negative, the first input signal 401 received on the working electrode 337 may have a voltage of 400 millivolts (e.g., 500 millivolts - 100 millivolts from noise) while the second input signal 403 received on the reference electrode 339 may be clamped to 0 millivolts since it cannot have a negative voltage (e.g., the reference electrode 339 is clamped to ground potential, which cannot be negative). In this scenario, because the reference electrode 339 is clamped to ground or zero, taking the difference between the first input signal 401 received on the working electrode 337 (e.g., 400 millivolts) and the second input signal 403 received on the reference electrode 339 (e.g., 0 millivolts) may make it appear as if the true value of the first input signal 401 received on the working electrode 337 is 400 millivolts rather than its true value of 500 millivolts.

[0087] Accordingly, aspects of the present disclosure provide techniques to reduce the effects / impact of environmental or other noise, thereby improving the integrity of the analyte measurements performed by the sensor. For example, in some cases, these techniques may involve applying a voltage offset to the reference electrode 339. The voltage offset may result in the input signals received from the reference electrode 339 and the working electrode 337 “floating” on top of the noise, allowing a differential amplifier, such as the third operational amplifier 414 in FIG. 4, to effectively filter out the noise in the input signals and generate an output signal that more accurately represents a measured analyte.

[0088] For example, as shown in FIG. 4, the ASIC 400 is configured to receive the first input signal 401 from the working electrode 337 having a first voltage (VWE) representing a measured analyte of a user of the wearable device (e.g., SS 8). Additionally, as shown, the ASIC 400 is configured to receive the second input signal 403 from the reference electrode 339 having a second voltage (VRE), which may be used as a reference to determine a value of the measured analyte. In some cases, as discussed above due to certain environmental factors in which the wearable device operates, the first input signal 401 and the second input signal 403 may also include a certain amountof noise, which may negatively affect an accuracy of the measured analyte. In other words, the first input signal 401 may include the first voltage (VWE) representing a measured analyte as well as a certain amount of voltage attributed to the noise (Vnoise). Similarly, the second input signal 403 may include the second voltage (VRE) as well as a certain amount of voltage attributed to the noise (Vnoise). In some cases, the added noise may have a positive voltage or a negative voltage.

[0089] In some embodiments, to ensure that this added noise may be successfully or substantially removed and to improve the accuracy of the measured analyte, an offset voltage may be applied to the first input signal 401 from the working electrode 337 and the second input signal 403 from the reference electrode 339 to raise the voltages of the first input signal 401 and the second input signal 403 high enough so that, when the noise has a negative voltage, the second input signal 403 does not get clamped to zero, which may otherwise cause issues in determining a true value of the first input signal 401 received from the working electrode 337 as described above.

[0090] For example, as shown at 420 in FIG. 4, an offset voltage may be applied (e.g., added) to the second input signal 403 from the reference electrode 339, resulting in the second input signal 403 having a voltage represented by VRE + Vnoise + Voffset. Similarly, the offset voltage may also be applied (e.g., added) to the first input signal 401 from the working electrode 337, resulting in the first input signal 401 having a voltage represented by VWE + Vnoise + Voffset. Thereafter, as shown, the first input signal 401 from the working electrode 337 may be input into the first operational amplifier 406 configured to output the first output signal 410 based on the first input signal 401 from the working electrode 337. Similarly, the second input signal 403 from the reference electrode 339 may be input into the second operational amplifier 408 configured to output a second output signal 412 based on the second input signal 403 from the reference electrode 339. Thereafter, the first output signal 410 (e.g., corresponding to the first input signal 401 from the working electrode 337) and the second output signal 412 (e.g., corresponding to the first input signal 401 from the working electrode 337) may then be input into the third operational amplifier 414 (e.g., a differential amplifier). The third operational amplifier 414 is configured to effectively remove the noise (Vnoise) from the first signal and the second signal and output an output signal having an output voltage (Vout) representing a differential voltage between the first voltage of the first input signal 401 from the working electrode 337 and the second voltage of the second input signal 403 from the referenceelectrode 339 (e.g., VWE-VRE) and the added voltage offset (Voffset). In other words, the output voltage is equal to Vout = (VWE-VRE) + Voffset.

[0091] The output signal may then be provided to the ADC 418, which is configured to convert the third output signal 413 from an analog signal to a digital signal. Thereafter, the digital output signal may be provided to one or more processors (e.g., the one or more processors 11) for further processing. For example, in some embodiments, the one or more processors may be configured to subtract the voltage offset from the digital output signal to obtain a true value of the first input signal 401 from the working electrode 337 representing a measured analyte concentration level of the user of SS 8. The measured analyte concentration level the user of SS 8 may then be communicated by analyte sensor 10 (e.g., via Bluetooth) to a display device (e.g., display device 120).

[0092] In some embodiments, the offset voltage may also be converted to digital counts by the ADC 418. For example, in some embodiments, the ASIC 400 may include a multiplexer that may be configured to direct which signal (e.g., output from the third operational amplifier 414 or the offset voltage) may be converted to digital counts by the ADC 418 at certain times.

[0093] In some embodiments, a value of the offset voltage (Voffset) may be selected by the wearable device (e.g., using the one or more processors) to be high enough so that the reference electrode 339 is not clamped to ground, such as 100 millivolts. In some embodiments, the offset voltage may be in the range of 50 millivolts to 100 millivolts. In some embodiments, the offset voltage may be greater than 100 millivolts, such as within a range of 101 millivolts to 200 millivolts. In some embodiments, the offset voltage may also be selected to be low enough such that the third operational amplifier 414 or the first operational amplifier 406 is not clamped on the high side. In some embodiments, the offset voltage may be dynamically chosen depending on an analyte that is being measured. For example, the one or more processors of the wearable device may, in some embodiments, select a type of analyte to measure and thereafter select an offset voltage corresponding to the type of analyte to be measured. In some embodiments, the voltage offset may be selected based on an estimate or value of noise (e.g., Vnoise). For example, the one or more processors may determine an amount of noise based on one or more voltage measurements or value associated with one or more portions of ASIC 400 or ASIC 500 and then use that to select the voltage offset to be larger than Vnoise.

[0094] Additionally, in some embodiments, the ASIC 400 may include an additional switch 422 that may be used to selectively apply or not apply the voltage offset to the first input signal 401 from the working electrode 337 and the second input signal 403 from the reference electrode 339. For example, in some embodiments, the additional switch 422 may be used to connect the voltage offset to the working electrode 337 and the reference electrode 339 such that the voltage offset is added to the first input signal 401 and the second input signal 403 while in other embodiments, the additional switch 422 may be used to connect the reference electrode 339 to ground.

[0095] Similarly, as shown at 520 in FIG. 5, an offset voltage may be applied (e.g., added) to the first input signal 501 from the working electrode 337 and the second input signal 503 from the reference electrode 339. As a result of the added voltage offset, the first input signal 501 that is input into the operational amplifier 506 may have a voltage represented by VWE + Vnoise + Voffset. Similarly, as a result of the added voltage offset the second signal may have a voltage represented by VRE + Vnoise + Voffset. The voltage offset may be coupled to ground 514.

[0096] Additionally, in some embodiments, the ASIC 500 may include an additional switch 522 that may be used to selectively apply or not apply the voltage offset to the first input signal 501 from the working electrode 337 and the second input signal 503 from the reference electrode 339. For example, in some embodiments, the additional switch 522 may be used to connect the voltage offset to the working electrode 337 and the reference electrode 339 such that the voltage offset is added to the first input signal 501 and the second input signal 503 while, in other embodiments, the additional switch 522 may be used to connect the reference electrode 339 to ground.High Impedance Switches

[0097] In some cases, when the wearable device (e.g., SS 8) is in an idle mode and not performing measurements of an analyte concentration level (e.g., between measurements or during time when additional measurements may not be physiologically relevant or significant, for instance during a time period when an analyte level would not change significantly (e.g., 10 seconds)), charge may accumulate on the working electrode 337 and reference electrode 339 of the analyte sensor(s) 10, which may affect the accuracy of potentiometric -based analyte measurements (e.g., measurements of an analyte concentration level). For example, in some cases, during a first period in time, theanalyte sensor(s) 10 is charged up to 300 millivolts representing a normal concentration of potassium of the user of the wearable device. However, in some cases, during a second period in time, the potassium of the user may decrease rapidly, resulting in a potassium concentration corresponding to 200 millivolts. In this scenario, the charge that has built up on the analyte sensor(s) 10 due to the previous 300 millivolt potassium concentration may take a significant amount of time to dissipate (e.g., due to the high impedance of the analyte sensor(s) 10) in order for the analyte sensor(s) 10 to reach a new equilibrium. Accordingly, when the wearable device measures the potassium level at the second period of time, a portion of the additional accumulated charge from the previous 300 millivolt potassium concentration may remain, leading to an incorrect potassium measurement at the second period of time.

[0098] Additionally, in some cases, the accumulated charge may be due to leakage currents associated with an AFE of the wearable device. For example, while relatively low, there may be instances in which charge may leak out of the operational amplifiers of the AFE (e.g., operational amplifiers 406, 408, 414, and / or 506) and accumulate on the working electrode 337 and / or reference electrode 339 of the analyte sensor(s) 10 (e.g., due to the input bias current of the amplifiers), which may cause inaccurate analyte measurements.

[0099] Accordingly, to avoid the scenarios described above in which accumulated charge on the working electrode 337 and / or reference electrode 339 of the analyte sensor(s) 10 negatively affects an accuracy of analyte measurements performed by the wearable device, the ASICs 400 and 500 may include one or more high impedance switches. The one or more high impedance switches may be used to selectively short the working electrode 337 and / or reference electrode 339 of the analyte sensor(s) 10, removing the accumulated charge. The working electrode 337 and / or reference electrode 339 of the analyte sensor(s) 10 may then be un-shorted or coupled, allowing the analyte sensor(s) 10 to reach a new equilibrium more quickly and allow the wearable device (e.g., SS 8) to more accurately measure an analyte concentration of a user.

[0100] For example, as shown, the ASICs 400 and 500 of FIGS. 4 and 5, respectively, include one or more switches, such as switches SI, S2, S3, and S4. In some embodiments, the one or more switches may each have a significantly high open state impedance, such as greater than one tera-ohm (TQ). In some embodiments, the one or more switches may be located on a die of the ASICs 400 and 500, the analyte sensor(s)10, or anywhere located after the analyte sensor(s) 10 and before the operational amplifiers 406, 408, and 506.

[0101] In some embodiments, the one or more switches may be used to selectively short the working electrode 337 and the reference electrode 339 of the analyte sensor(s) 10 to remove any accumulated charge on the working electrode 337 and the reference electrode 339. Additionally, the one or more switches may be used to prevent any leakage current from the operational amplifiers of the ASICs 400 and 500 from accumulating on the working electrode 337 and the reference electrode 339.

[0102] For example, as shown in FIGS. 4 and 5, when analyte measurements are not needed or not being performed, the wearable device may be configured to maintain the one or more switches in an idle configuration. For example, as shown in FIGS. 4 and 5, when in the idle configuration, all switches (e.g., SI, S2, S3, and S4) may be maintained in an open position, isolating the working electrode 337 and the reference electrode 339 of the analyte sensor(s) 10 from the operational amplifiers of the ASICs 400 and 500.

[0103] Thereafter, prior to an analyte measurement being performed, the wearable device may be configured to close switch SI, shorting the working electrode 337 and the reference electrode 339 and equalizing any charge that has accumulated on the working electrode 337 and / or the reference electrode 339. In some embodiments, while switch SI is closed, the wearable device may be configured to maintain switches S2, S3, and S4 in an open position. In some embodiments, the shorting of the working electrode 337 and the reference electrode 339 may be performed according to a fixed cycle irrespective of an analyte measurement cycle.

[0104] Thereafter, with reference to FIG. 4, in order to perform the analyte measurement, the wearable device may open switch SI again (e.g., so that the working electrode 337 and the reference electrode 339 are not shorted) and close switches S2 and S3, electrically coupling the working electrode 337 and the reference electrode 339 to the first operational amplifier 406 and the second operational amplifier 408. Additionally, during the analyte measurements, the wearable device may be configured to maintain switch S4 in an open position.

[0105] Alternatively, with reference to FIG. 5, in order to perform the analyte measurement, the wearable device may first close switch SI and open switches S2, S3, and S4, shorting the working electrode 337 and the reference electrode 339 and equalizingany charge that has accumulated on the working electrode 337 and / or the reference electrode 339. Thereafter, the wearable device may close switches S2 and S3 and open switches SI and S4, allowing the first input signal 501 to be received by the operational amplifier 506. As discussed above, in some cases, the wearable device may operate the additional switch 522 to either fix a voltage of the reference electrode 339 (e.g., VRE) to the voltage offset as shown at 520 or to ground as shown at 512.

[0106] In some embodiments, the one or more switches may be used to establish a baseline for the operational amplifiers and ADC of the ASIC 400 shown in FIG. 4 at zero input, which may be subtracted from a subsequent analyte measurement. For example, in some embodiments, the wearable device may be configured to close switch S4 and open switches SI, S2, and S3, thereby shorting the inputs of the operational amplifiers 406 and 408. By shorting the inputs of the operational amplifiers 406 and 408, a baseline voltage measurement may be obtained at the ADC 418. In some embodiments, the wearable device may be configured to obtain the baseline voltage measurement (e.g., by shorting the inputs of the operational amplifiers 406 and 408) prior to every analyte measurement, or at preset intervals, such as every hour, or based on temperature change beyond some preset threshold.

[0107] Thereafter, when performing an analyte measurement, this baseline voltage measurement may then be subtracted from the filtered third output signal 413 (e.g., representing the differential between the first input signal 401 and the second input signal 403) at the ADC 418 in order to obtain a true value of an analyte concentration level being measured. In some embodiments, while calibrating, the wearable device may be configured to maintain switches SI, S2, and S3 in an open position.

[0108] In some cases, the sequence of events described above related to the one or more switches may be performed periodically according to an analyte measurement cycle or may be dynamically performed based on a certain event, such as detection of an anomaly in the measured analyte (e.g., a lot of noise). For example, the wearable device detects an anomaly in an analyte measurement, the wearable device may be configured to short the working electrode 337 and the reference electrode 339 (e.g., switch SI may be closed and switches S2, S3, and S4 may be opened) and then a new analyte measurement may be performed (e.g., after switches SI and S4 may be opened and switches S2 and S3 may be closed).

[0109] In some embodiments, the shorting of the working electrode 337 and the reference electrode 339 may be a “direct” short or may be a short through some amount of resistance depending on sensor behavior. For example, in some cases, a 100 kiloohm resistor may be added in series with switch SI to control a rate at which the accumulated charge is dissipated, which may reduce any negative impacts to the analyte sensor(s) 10.Wire Bonded. Analyte S ens or-to -Front End. Interface for Reduced. Leakage Currents

[0110] Hardware for potentiometric -based analyte measurements requires extremely high impedance at the AFE or ASIC. For example, the required impedance may be on the order of greater than 10 T to obtain clinically useful analyte measurements. In a traditional approach, where a printed circuit board assembly (PCBA) interfaces with the analyte sensor, this impedance would be comprised not only of the impedance of the electronics within the integrated circuit, but also the impedance of any electronics located on the PCB and any other outer housing materials where leakage currents may flow.

[0111] Traditionally, an ASIC for potentiometric-based analyte measurements may be electrically coupled (e.g., soldered) to a PCB of an analyte sensor system and the PCB would include electrical traces and electrical pads to which an analyte sensor of the analyte sensor system would be coupled. In order to ensure high impedance to isolate the analyte sensor from the leakage currents for obtaining accurate analyte measurements from the analyte sensor, the electrical traces would need to be insulated. However, traditional PCB materials (e.g., flame retardant 4 (FR4)) may not be sufficient to achieve a sufficiently high impedance. As such, different materials (e.g., Rogers 4350b material) would need to be used to ensure a sufficient amount of impedance, which may be costly and introduce other adverse manufacturing constraints. Additionally, when the analyte sensor is coupled to the PCB in this manner (e.g., soldered), the connection requires mechanical protection in the form of an epoxy encapsulant layer. However, traditional epoxy materials for this encapsulant layer may not have a high enough impedance, resulting in more costly materials having to be used.

[0112] Accordingly, aspects of the present disclosure provide techniques to avoid the need for costly materials while still helping to avoid leakage currents. For example, in some embodiments, to avoid the need for costly materials, analyte sensor may be bonded directly to electrical pads on the ASIC using a pair of insulated wires. Portions of the wires may be suspended above or be above the PCB with sufficient distance from thePCB to reduce or prevent interference and leakage current(s) from one or more PCB components. Accordingly, this may allow standard PCB materials to be used since, when using the wires, the input impedance seen by the sensor does not depend on the dielectric properties of the PCB or any propensity for current leakage pathways therein. Additionally, to further improve performance, the bond wires would be encapsulated in a high resistivity material to improve their insulating capabilities, resistance to moisture, as well as prevent movement that may lead to triboelectric effects.

[0113] For example, FIG. 6 illustrates an example wearable device 600 in which bonding wires may be used to electrically couple an analyte sensor to an ASIC. The wearable device 600 may be an example of the SS 8 described with respect to FIGS. 1, 2, 3A, 3B, and 3C and / or the wearable device described with respect to FIGS. 4 and 5.

[0114] As shown, the wearable device 600 includes an ASIC 602 that is electrically coupled (e.g., soldered) to a PCB 604. In some embodiments, the ASIC 602 may be an example of the ASIC 400 or ASIC 500. Additionally, in some embodiments, the PCB 604 may be an example of the PCB 499 or the PCB 599. Additionally, as shown, the wearable device 600 includes the analyte sensor(s) 10, which may be directly bonded to a plurality of electrical pads 606 (e.g., electrodes) on the ASIC 602 using a pair of bonding wires 608. For example, the pair of bonding wires 608 may include a first bonding wire that electrically couples the working electrode 337 to a first electrical pad of the pair of electrical pads 606. The pair of bonding wires may also include a second bonding wire that electrically couples the reference electrode 339 to a second electrical pad of the pair of electrical pads 606.

[0115] As noted above, the pair of bonding wires 608 may isolate the analyte sensor(s) 10 from dielectric properties of the PCB 604 and a propensity of the PCB 604 for leakage currents. The pair of bonding wires 608 may thus reduce the noise (e.g., due to leakage current) of signals received at the electrical pads 606 (e.g., relative to traces on a PCB). In some embodiments, the pair of bonding wires 608 may be positioned within the wearable device 600 such that they do not touch the PCB 604. For example, the pair of bonding wires 608 may be positioned such that there is an air gap 610 between the pair of bonding wires 608 and the PCB 604. Because a dielectric constant of air is low (e.g., approximately one), the air gap 610 provides for high impedance between the working electrode 337 and the PCB 604, reducing the chances that any leakage currents may affect the working electrode 337. Additionally, the bonding wires may also be encapsulatedusing a high resistivity material 612, such as integrated circuit molding materials and / or epoxies, to improve performance of the analyte sensor(s) 10. The high resistivity material 612 may also provide moisture protection and help to ensure that the pair of bonding wires 608 do not move, which may otherwise lead to triboelectric effects.

[0116] In some embodiments, rather than using the pair of bonding wires 608, the analyte sensor(s) 10 may be directly coupled to the pair of electrical pads 606 of the ASIC.Multi-Layer Guard Band, for Reduced. Leakage Currents

[0117] As shown in FIG. 7, rather than using a pair of bonding wires to couple the working electrode 337 and the reference electrode 339 of the analyte sensor(s) 10 to the ASIC 602 of the wearable device 600, the working electrode 337 and the reference electrode 339 may instead by coupled to the ASIC 602 using electrical traces disposed on the PCB 604 of the wearable device 600. For example, in some embodiments, the working electrode 337 may be electrically coupled to the ASIC 602 using the first electrical trace 428 disposed on the PCB 604 and the reference electrode 339 may be electrically coupled to the ASIC 602 using the second electrical trace 430 disposed on the PCB 604.

[0118] However, when using the first electrical trace 428 on the PCB 604 to couple the working electrode 337 to the ASIC 602, the working electrode 337 may be susceptible to leakage current since the materials of the PCB 604 do not traditionally provide for high impedance. As such, charge or current from an input signal received from the working electrode 337 (e.g., the first input signal 401, 501) may have the potential to leak out of the first electrical trace 428 to surrounding circuitry with different potentials on the PCB 604, which may cause inaccuracies in analyte measurements performed by the analyte sensor(s) 10. Similarly, charge or current from other electronic sources on the PCB 604 may also have the potential to leak into the first electrical trace 428 on the PCB 604, also causing inaccurate analyte measurements.

[0119] Accordingly, to help reduce leakage currents and associated noise when at least the working electrode 337 is coupled to the ASIC 602 using the first electrical trace 428, a guard driver and one or more guard bands may be used. For example, as discussed above with respect to FIG. 4, in some embodiments, the fourth operational amplifier 424 of the ASIC 400 may receive and buffer the third output signal 413. Thereafter, the fourth operational amplifier 424 outputs the buffered third output signal 413 to the third electrical trace 426 on the PCB 499 that is positioned adjacent to, but does not touch, thefirst electrical trace 428. In some cases, the buffered third output signal 413 output to the third electrical trace 426 may have a same or substantially similar potential (e.g., voltage level) as, or very close to that of, the first input signal 401 received on the first electrical trace 428. The potential or voltage of buffered third output signal 413 output to the third electrical trace 426 may thus reduce noise of a signal (e.g., voltage) received from working electrode 337.

[0120] In some embodiments, the third electrical trace 426 may comprise one or more guard bands that surround the first electrical trace 428. The guard bands of third electrical trace may be an electrically conductive material (e.g., copper, etc.). For example, FIG. 8A, 8B, 8C, and 8D illustrate various views of the third electrical trace 426. As shown, the third electrical trace 426 includes a plurality of guard bands 802, 804, 806, and 808, which are configured to surround the first electrical trace 428 on which the first input signal 401 or 501 is received from the working electrode 337. In some embodiments, the plurality of guard bands 802, 804, 806, and 808 may be disposed on or embedded into the PCB 604 of FIGS. 6 and 7.

[0121] FIG. 8A illustrates a top layer of the third electrical trace 426 including the guard band 802, which is disposed on top of or above the first electrical trace 428. FIG. 8B illustrates a middle layer of the third electrical trace 426 including the guard bands 804 and 808, which are disposed on either side of or next to the first electrical trace 428. FIG. 8C illustrates a bottom layer of the third electrical trace 426 including the guard band 806, which is disposed below the first electrical trace 428. FIG. 8D illustrates a cross section of the third electrical trace 426 and the first electrical trace 428, illustrating the guard bands 802, 804, 806, and 808 surrounding the first electrical trace 428. It is appreciated that each of guard bands 802, 804, 806, and 808 may be separated from the first electrical trace 428 by a material or layer (e.g., PCB material). The guard bands 802, 804, 806, and 808 may be traces or copper planes on the PCB.

[0122] In some embodiments, the buffered third output signal 413 that is output by the fourth operational amplifier 424 in FIG. 4 may be output to the guard bands 802, 804, 806, and 808 of the third electrical trace 426 surrounding the first electrical trace 428. In some embodiments, as described above, the buffered third output signal 413 that is output by the fourth operational amplifier 424 may have a same or substantially similar potential as the first input signal 401 received on the first electrical trace 428 from the working electrode 337, which may protect the first input signal 401 received on the first electricaltrace 428 from any leakage currents, thereby improving accuracy of an analyte measurement associated with the first input signal 401.

[0123] In some embodiments, with reference to FIG. 7, the guard bands 802, 804, 806, and 808 may extend the entire length of the first electrical trace 428 from a point on the PCB 604 (e.g., or PCB 499 or PCB 599) at which the working electrode 337 of the analyte sensor(s) 10 is coupled to the PCB 604 to a point at which the first electrical trace 428 connects to an input on the ASIC 602 (e.g., working electrode pin 402 of FIG. 4).

[0124] In some embodiments, the guard bands for reducing leakage current associated with the working electrode 337 may be used in combination with the wire bonding described above. For example, in some embodiments, the reference electrode 339 of the analyte sensor(s) 10 may be coupled to an electrical pad 606 on the ASIC 602 using a bonding wire while the working electrode 337 of the analyte sensor(s) 10 may be coupled to the ASIC 602 via the first electrical trace 428 on the PCB 604 that may be surrounded and protected by the guard bands 802, 804, 806, and 808.

[0125] In some embodiments, a gain of the fourth operational amplifier 424 of the guard driver in FIG. 4 may depend on a gain of the operational amplifiers 406, 408, and / or 414 in the instrumentation amplifier of FIG. 4. For example, a gain of the fourth operational amplifier 424 may be set such that a total gain of the ASIC 400 is 1. If the gain of the instrumentation amplifier (e.g., operational amplifiers 406, 408, and / or 414) is 2, then the gain of the fourth operational amplifier 424 may be set to 1 / 2 so that the gain of the buffered third output signal 413 from the fourth operational amplifier 424 is 1 to ensure guard potential (e.g., of third electrical trace 426) is the same or substantially similar to a potential of the first input signal 401 to minimize leakage current.Dynamic Power On / Off

[0126] A lifetime of wearable devices, such as the SS 8 described with respect to FIGS. 1, 2, 3A, 3B, and 3C and / or the wearable device described with respect to FIGS. 4, 5, and 6, is frequently limited by a capacity of a battery, such as the battery 302 of FIG. 3C. For potentiometric-based analyte sensors, in particular, high-powered operational amplifiers may often be necessary to achieve a high input impedance required for accurate analyte measurements. When these high-powered operational amplifiers are turned on, a significant amount of energy is consumed from the battery, which may reduce a lifespan of the wearable device.

[0127] Accordingly, to conserve energy of the battery and improve the lifespan of a wearable device, aspects of the present disclosure provide techniques for dynamically powering on and off an ASIC, including the high-powered operational amplifiers, of the wearable device. For example, as will be described in more detail below, an ASIC of the wearable device (e.g., ASIC 400, 500, and / or 602) may be dynamically powered down when analyte measurements are not being performed and may, thereafter, be powered on when the analyte measurements are being performed. After the analyte measurements are performed, the ASIC may then be powered off again.

[0128] For example, potentiometric -based analyte sensors (e.g., analyte sensor(s) 10), unlike amperometric -based analyte sensors, may be allowed to float without impacting future analyte measurements. As such, when analyte measurements are not needed, an ASIC or AFE of a wearable device, which interfaces with and controls the potentiometric-based analyte sensor, may be switched off to save power, including the high-power operational amplifiers and guard bands included therein.

[0129] For example, FIG. 9A illustrates a wearable device 900 for continuous potentiometric-based analyte measurements of a user. The wearable device 900 may be an example of the SS 8 described with respect to FIGS. 1, 2, 3A, 3B, and 3C and / or the wearable device described with respect to FIGS. 4, 5, and 6.

[0130] As shown, the wearable device 900 includes a controller 902, an ASIC 904, a potentiometric-based continuous analyte sensor(s) 906, a battery 908, a temperature sensor 910, and a force sensor or accelerometer 912. In some embodiments, the controller 902, the ASIC 904, the battery 908, the temperature sensor 910, and the force sensor or accelerometer 912 may be part of a sensor electronics module of the wearable device, such as the sensor electronic module 12 of the SS 8 described with respect to FIGS. 1 and2.

[0131] The ASIC 904 may be an example of the ASIC 400 described with respect to FIG. 4, the ASIC 500 described with respect to FIG. 5, and / or the ASIC 602 described with respect to FIG. 6. Accordingly, in some embodiments, the ASIC 904 may include one or more operational amplifiers for performing potentiometric -based analyte measurements, such as the operational amplifiers described with respect to FIGS. 4 and5.

[0132] In some embodiments, the controller 902 may include one or moreprocessors, such as the one or more processors 11. The controller 902 may be used to control the ASIC 904 and perform other processing functions, such as receiving and processing analyte measurements from the ASIC 904, transmitting analyte data corresponding to the analyte measurements to a display device for display to a user, and other functions described above with respect to the one or more processors 11. In some embodiments, the potentiometric-based analyte sensor(s) 906 may be an example of the analyte sensor(s) 10 and may include the working electrode 337 and reference electrode 339.

[0133] In some embodiments, the battery 908 may be used to supply power to the controller 902, the ASIC 904, the potentiometric -based analyte sensor(s) 906, the temperature sensor 910, and the force sensor or accelerometer 912. For example, as shown in FIG. 9A, power from the battery 908 may be received at an input 914 of the controller 902. As shown, the power received from the battery 908 may have a voltage Vdd. Additionally, as shown, power from the battery 908 may be output by the controller 902 on an output pin 916 and received on an input pin 918 of the ASIC 904. The power received on the input pin 918 may have a voltage Vdd and may be used to power the ASIC 904 and the potentiometric-based analyte sensor(s) 906.

[0134] As noted above, the ASIC 904 may include one or more operational amplifiers for performing analyte measurements, which may consume a significant amount of power from the battery 908. In some embodiments, to help conserve power of the battery 908 when analyte measurements are not being performed, the controller 902 may be configured to dynamically power down the ASIC 904. For example, in some embodiments, when analyte measurements are not being performed or not needed, the controller 902 may be configured to open a power switch 920, cutting off or uncoupling the power to the ASIC 904 and the potentiometric-based analyte sensor(s) 906 to conserve power of the battery 908. Thereafter, when analyte measurements are needed or are to be performed, the controller 902 may be configured to close the power switch 920, allowing for the power from the battery 908 to be supplied to the ASIC 904 and potentiometricbased analyte sensor(s) 906 for performing the analyte measurements. As shown in the embodiment illustrated in FIG. 9A, the power switch 920 may be included within the controller 902.

[0135] FIG. 9B illustrates another example embodiment of the wearable device 900 in which an external power switch may be used to control power supplied to the ASIC904. For example, as shown, rather than including the power switch 920 that is internal to the controller 902, the wearable device 900 may instead include a power switch 922 that is external to the controller 902. In this embodiment, when analyte measurements are not being performed or not needed, the controller 902 may be configured to output a first control signal on a control line 924 to the power switch 922, instructing the power switch 922 to open, thereby cutting off the power to the ASIC 904 and the potentiometric -based analyte sensor(s) 906 to conserve power of the battery 908. Thereafter, when analyte measurements are needed or are to be performed, the controller 902 may output a second control signal on the control line 924 to the power switch 922, instructing the power switch 922 to close, thereby allowing for the power from the battery 908 to be supplied to the ASIC 904 and potentiometric-based analyte sensor(s) 906 for performing the analyte measurements.

[0136] FIG. 9C illustrates another example embodiment of the wearable device 900 in which a low power mode associated with operational amplifiers included within the ASIC 904 may be used to conserve the power of the battery 908. For example, rather than completely shutting off the power to the ASIC 904, the controller 902 may be configured to output control signaling to the ASIC 904 to place the operational amplifiers included within the ASIC 904 into the low power mode to conserve power. For example, in the embodiment of FIG. 9C, when analyte measurements are not being performed or not needed, the controller 902 may be configured to output a first control signal on a control line 926 to the ASIC 904, instructing the operational amplifiers of the ASIC 904 to enter the low power mode. While in the low power mode, the operational amplifiers may consume significantly less power (e.g., 5 nano-amps) while still allowing the ASIC 904 to be powered. The low power mode may allow for a lower settling time when an analyte measurement is to be performed as compared to the full shutdown mode. Thereafter, when analyte measurements are needed or are to be performed, the controller 902 may output a second control message on the control line 926 to ASIC 904, instructing the operational amplifiers of the ASIC 904 to exit the low power mode.

[0137] In some embodiments, the controller 902 may be configured to dynamically supply power to the ASIC 904 (e.g., with respect to FIGS. 9A and 9B) or dynamically instruct the operational amplifiers to enter / exit the low power mode (e.g., with respect to FIG. 9C) according to a particular analyte measurement schedule or periodicity, or based on certain conditions. For example, in some embodiments, the analyte measurementschedule may evenly distribute the analyte measurements in type, having a constant period between each measurement. Accordingly, the controller may be configured to dynamically cut off the power to the ASIC 904 or instruct the operational amplifiers to enter the low power mode, based on the analyte measurement schedule, when the analyte measurements are not being performed. Thereafter, when analyte measurements are to be performed based on the analyte measurement schedule, the controller 902 may be configured to dynamically supply the power to the ASIC 904 or instruct the operational amplifiers to exit the low power mode.

[0138] In some cases, evenly distributing the analyte measurement according to the analyte measurement schedule may help to avoid any random noise. For example, by evenly distributing the measurements, there may be a higher likelihood that at least one of the measurements will not overlap with the random noise. In some cases, random noise could be caused by a variety of things, such as a strong light shining on the analyte sensor system, nearby electronic equipment turning on, a phone or RF signal coming too close to the analyte sensor system, etc.

[0139] In some cases, the periodicity (e.g., period between each measurement in the analyte measurement schedule) may be based on a typical rate of change of an analyte (e.g., potassium ions) in a human body. In some cases, the periodicity may be optimized such that an impact to analyte measurements associated with the dynamic powering on and off the ASIC 904 is minimized while the reduction in power consumption is maximized.

[0140] In some cases, where the wearable device 900 is experiencing a significant amount of noise (e.g., due to one or more of the sources of noise described above), the wearable device 900 may be configured to perform measurements more frequently to compensate for the noise. In such cases, the periodicity of the analyte measurements may be more frequent (e.g., periodicity dynamically adjusted). As such, the controller 902 may be configured to supply the power to the ASIC 904 (or instruct the operational amplifiers to exit the low power mode) more often to help compensate for the noise.

[0141] In some cases, the periodicity may depend on a type of analyte that is being measured. For example, potassium ion measurements may have one periodicity while magnesium ion measurements may have another periodicity.

[0142] In some cases, the periodicity may be based on a transmission schedule ofanalyte measurements or analyte data to a display device, such as display device 150. For example, the controller 902 may be configured to transmit the analyte measurements to the display device according to a particular schedule. Since these transmissions may be performed using wireless communications (e.g., RF, Bluetooth, etc.), which may cause noise to the measurements, the controller 902 may be configured to cut off power to the ASIC 904 whenever the wireless transmission of the analyte measurements or other data is occurring, which may reduce self-interference (e.g., interference caused to the analyte measurements due to the wireless transmissions by the wearable device).

[0143] In some cases, the conditions that may be taken into account when dynamically supplying power to the ASIC 904 or dynamically instructing the operational amplifiers to enter / exit the low power mode may include whether or not an analyte measurement is changing significantly between measurements. For example, if the controller 902 detects that an analyte measurement is changing significantly between measurements, the controller 902 may instruct the ASIC 904 to perform additional measurements to confirm whether the change in measurement is valid or is being affected by environmental noise. In such cases, the controller 902 may be configured to supply the power to the ASIC 904 (or instruct the operational amplifiers to remain out of the low power mode) to perform these additional measurements.

[0144] In some cases, large temperature changes may affect the analyte measurements. For example, as shown in FIGS. 9A, 9B, and 9C, the wearable device 900 includes the temperature sensor 910 that may be used to measure a temperature associated with the wearable device 900. As such, if the controller 902 detects a large temperature change, the controller 902 may instruct the ASIC 904 to perform additional measurements to ensure that the analyte measurements are accurate. In such cases, the controller 902 may be configured to supply the power to the ASIC 904 (or instruct the operational amplifiers to remain out of the low power mode) to perform these additional measurements.

[0145] In some embodiments, as shown in FIGS. 9A, 9B, and 9C, the wearable device 900 also includes the force sensor or accelerometer 912 that may be used to trigger the analyte measurements. For example, when a user presses or taps the force sensor or accelerometer, the controller 902 of the wearable device 900 may be configured to dynamically supply power to the ASIC 904 (or instruct the operational amplifiers of the ASIC 904 to exit the lower power mode) to perform an analyte measurement.

[0146] In some embodiments, a user of the wearable device 900 may trigger an analyte measurement using an application on the display device (e.g., analyte sensor application 121 on the display device 150) or an NFC scan of the display device on the wearable device 900. In such cases, when triggered, the controller 902 of the wearable device 900 may be configured to dynamically supply power to the ASIC 904 (or instruct the operational amplifiers of the ASIC 904 to exit the lower power mode) to perform an analyte measurement.Example Operations of a Wearable Device

[0147] FIG. 10 shows an example of a method 1000 for performing analyte measurements. The method 1000 may be performed by a wearable device, such as the SS 8 described with respect to FIGS. 1, 2, 3A, 3B, and 3C and / or the wearable device described with respect to FIGS. 4, 5, 6, 7, 9A, 9B, and / or 9C. In some embodiments, method 1000 may be performed by one or more processors of the wearable device, such as the one or more processors 11 , based on instructions stored in one or more memories. For example, in some embodiments, the wearable device may include one or more memories, such as the one or more memories 14, including instructions that, when executed by the one or more processors, cause the wearable device to perform the method 1000. As shown, method 1000 begins at 1002 receiving, at one or more operational amplifiers of an ASIC (e.g., ASIC 400) of the wearable device (e.g., first operational amplifier 406), a first input signal from a working electrode of a transcutaneous analyte sensor, the first input signal may have a first noise level.

[0148] At 1004, the wearable device receives, at the one or more operational amplifiers of the ASIC (e.g., second operational amplifier 408), a second input signal from a reference electrode of the analyte sensor.

[0149] At 1006, the wearable device outputs, from the one or more operational amplifiers (e.g., third operational amplifier 414) to an analog to digital converter (ADC) of the wearable device (e.g., ADC 418), an output signal representing a differential between the first input signal and second input signal. The output signal may have a second noise level that is less than the first noise level.

[0150] At 1008, the wearable device converts, by the ADC, the output signal to a digital signal.

[0151] At 1010, the wearable device receives, by one or more processors of thewearable device, the digital signal from the ADC and processing the digital signal to determine the analyte concentration level of the user, wherein the ASIC, the ADC, and the one or more processors are operatively coupled by a printed circuit board (PCB) (e.g., PCB 499).

[0152] In some embodiments, method 1000 further includes receiving and filtering, by a low pass filter (LPF) of the wearable device (e.g., LPF 416), the output signal and providing the output signal to the ADC after the filtering.

[0153] In some embodiments, method 1000 further includes applying an offset voltage to the second signal associated with the reference electrode. In some embodiments, the offset voltage comprises approximately 100 millivolts or more.

[0154] In some embodiments, the working electrode is coupled with a first input of a first operational amplifier. In some embodiments, the reference electrode is coupled with a first input of a second operational amplifier. In some embodiments, method 1000 further includes amplifying, by the first operational amplifier, the first input signal. In some embodiments, method 1000 further includes outputting, by the first operational amplifier, the amplified first input signal to a first input of a third operational amplifier. In some embodiments, method 1000 further includes amplifying, by the second operational amplifier, the second input signal. In some embodiments, method 1000 further includes outputting, by the second operational amplifier, the amplified second input signal to a second signal of the third operational amplifier.

[0155] In some embodiments, the ASIC includes a plurality of input switches electrically coupled between the analyte sensor and the first inputs of the first and second operational amplifiers.

[0156] In some embodiments, method 1000 further includes operating the plurality of switches. In some embodiments, operating the plurality of switches comprises, during a first period of time in which the analyte concentration level of the user is not being measured, maintaining the plurality of switches in an open position to electrically isolate the analyte sensor from the ASIC.

[0157] In some embodiments, operating the plurality of switches further comprises, during a second period of time in which the analyte sensor system is configured to measure the analyte concentration level of the user operating the plurality of switches such that the working electrode and reference electrode are shorted. In someembodiments, operating the plurality of switches further comprises, after a threshold amount of time that the working electrode and reference electrode have been shorted, operating the plurality of switches to: isolate the working electrode from the reference electrode, connect the working electrode to the first input of the first operational amplifier, and connect the reference electrode to the first input of the second operational amplifier.

[0158] In some embodiments, the working electrode of the analyte sensor is coupled with the first input of the first operational amplifier of the ASIC using a first bonding wire. In some embodiments, the reference electrode of the analyte sensor is coupled with the first input of the second operational amplifier of the ASIC using a second bonding wire.

[0159] In some embodiments, the working electrode of the analyte sensor is coupled with the first input of the first operational amplifier of the ASIC using a first electrical trace on the PCB. In some embodiments, the reference electrode of the analyte sensor is coupled with the first input of the second operational amplifier of the ASIC using a second electrical trace on the PCB.

[0160] In some embodiments, at least the first electrical trace is surrounded on four sides by one or more guard band electrical traces.

[0161] In some embodiments, method 1000 further includes outputting, by the one or more operational amplifiers, a second output signal, generated based on the first input signal, on the one or more guard band electrical traces. In some embodiments, the second output signal has a same gain as the first input signal.

[0162] In some embodiments, the one or more guard band electrical traces are configured to protect the first electrical trace from leakage currents.

[0163] In some embodiments, method 1000 further includes powering off the ASIC using one or more power switches during a first period of time in which the analyte concentration level of the user is not being measured.

[0164] In some embodiments, method 1000 further includes powering on the ASIC using the one or more power switches during a second period of time in which the analyte concentration level of the user are to be measured.

[0165] In some embodiments, method 1000 further includes powering on the ASIC using the one or more power switches based on a fixed periodicity or one or more triggerevents.

[0166] In some embodiments, the one or more trigger events are based on a temperature change or based on user input from a force sensor or accelerometer.

[0167] In some embodiments, method 1000 further includes powering off the ASIC using the one or more power switches after the analyte concentration level of the user has been measured.Example Communications Device

[0168] FIG. 11 depicts aspects of an example communications device 1100. In some aspects, communications device 1100 is a wearable device, such as the SS 8 described with respect to FIGS. 1, 2, 3A, 3B, and 3C and / or the wearable device described with respect to FIGS. 4, 5, 6, 7, 9A, 9B, and / or 9C.

[0169] The communications device 1100 includes a processing system 1105 coupled to the transceiver 1155 (e.g., a transmitter and / or a receiver). The transceiver 1155 is configured to transmit and receive signals for the communications device 1100 via the antenna 1160, such as the various signals and messages as described herein. The processing system 1105 may be configured to perform processing functions for the communications device 1100, including processing signals received and / or to be transmitted by the communications device 1100.

[0170] The processing system 1105 includes one or more processors 1110. In various aspects, the one or more processors 1110 may be representative of the one or more processors 11, as described with respect to FIG. 2. The one or more processors 1110 are coupled to a computer-readable medium / memory 1130 via a bus 1150. In some aspects, the computer-readable medium / memory 1130 may be representative of the one or more memories 14, as described with respect to FIG. 2. In certain aspects, the computer- readable medium / memory 1130 is configured to store instructions (e.g., computerexecutable code) that when executed by the one or more processors 1110, cause the one or more processors 1110 to perform the method 1000 described with respect to FIG. 10, or any aspect related to this method. Note that reference to a processor performing a function of communications device 1100 may include one or more processors 1110 performing that function of communications device 1100.

[0171] In the depicted example, computer-readable medium / memory 1130 stores code (e.g., executable instructions), such as code for receiving 1135, code for outputting1136, code for converting 1137, code for filtering 1138, code for providing 1139, code for amplifying 1140, code for operating 1141, code for maintaining 1142, code for isolating 1143, code for connecting 1144, code for powering off 1145, code for powering on 1146, and code for performing 1147. Processing of the code for receiving 1135, code for outputting 1136, code for converting 1137, code for filtering 1138, code for providing 1139, code for amplifying 1140, code for operating 1141, code for maintaining 1142, code for isolating 1143, code for connecting 1144, code for powering off 1145, code for powering on 1146, and code for performing 1147 may cause the communications device 1100 to perform the method 1000 described with respect to FIG. 10, or any aspect related to these methods.

[0172] The one or more processors 1110 include circuitry configured to implement (e.g., execute) the code stored in the computer-readable medium / memory 1130, including circuitry for receiving 1115, circuitry for outputting 1116, circuitry for converting 1117, circuitry for filtering 1118, circuitry for providing 1119, circuitry for amplifying 1120, circuitry for operating 1121, circuitry for maintaining 1122, circuitry for isolating 1123, circuitry for connecting 1124, circuitry for powering off 1125, circuitry for powering on 1126, and circuitry for performing 1127. Processing with circuitry for receiving 1115, circuitry for outputting 1116, circuitry for converting 1117, circuitry for filtering 1118, circuitry for providing 1119, circuitry for amplifying 1120, circuitry for operating 1121, circuitry for maintaining 1122, circuitry for isolating 1123, circuitry for connecting 1124, circuitry for powering off 1125, circuitry for powering on 1126, and circuitry for performing 1127 may cause the communications device 1100 to perform the method 1000 described with respect to FIG. 10, or any aspect related to these methods.Example Clauses

[0173] Implementation examples are described in the following numbered clauses:

[0174] Clause 1: A wearable device for performing analyte measurements, comprising: a transcutaneous analyte sensor configured to perform potentiometric-based measurements of an analyte concentration level of a user, wherein: the transcutaneous analyte sensor includes a working electrode for receiving a first input signal and a reference electrode for receiving a second input signal; and the first input signal and the second input signal are associated with the analyte concentration level of the user; and an application specific integrated circuit (ASIC) comprising: one or more operationalamplifiers configured to: receive the first input signal and the second input signal; and output an output signal representing a differential between the first input signal and second input signal; an analog to digital converter (ADC) configured to convert the output signal to a digital signal; one or more processors configured to receive the digital signal from the ADC and process the digital signal to determine the analyte concentration level of the user; and a printed circuit board (PCB) configured to operatively connect at least the ASIC, the ADC, and the one or more processors.

[0175] Clause 2: The wearable device of Clause 1, further comprising a low pass filter (LPF) configured to receive and filter the output signal from the one or more operational amplifiers and to provide the output signal to the ADC after filtering.

[0176] Clause 3: The analyte sensor system of any of Clauses 1-2, wherein the ASIC includes circuitry for outputting and applying an offset voltage to the second signal associated with the reference electrode.

[0177] Clause 4: The analyte sensor system of Clause 3, wherein the offset voltage comprises approximately 100 millivolts or more.

[0178] Clause 5: The analyte sensor system of any of Clauses 1-4, wherein: the working electrode is coupled with a first input of a first operational amplifier that is configured to: amplify the first input signal; and output the amplified first input signal to a first input of a third operational amplifier; the reference electrode is coupled with a first input of a second operational amplifier that is configured to: amplify the second input signal; and output the amplified second input signal to a second signal of the third operational amplifier.

[0179] Clause 6: The analyte sensor system of Clause 5, wherein the ASIC includes a plurality of input switches electrically coupled between the analyte sensor and the first inputs of the first and second operational amplifiers.

[0180] Clause 7: The analyte sensor system of Clause 6, wherein the one or more processors are configured to operate the plurality of switches.

[0181] Clause 8: The analyte sensor system of Clause 7, wherein: during a first period of time in which the analyte concentration level of the user is not being measured, the one or more processors are configured to maintain the plurality of switches in an open position to electrically isolate the analyte sensor from the ASIC.

[0182] Clause 9: The analyte sensor system of Clause 8, wherein, during a second period of time in which the analyte sensor system is configured to measure the analyte concentration level of the user, the one or more processors are configured to: operate the plurality of switches such that the working electrode and reference electrode are shorted; and after a threshold amount of time that the working electrode and reference electrode have been shorted, operate the plurality of switches to: isolate the working electrode from the reference electrode; connect the working electrode to the first input of the first operational amplifier; and connect the reference electrode to the first input of the second operational amplifier.

[0183] Clause 10: The analyte sensor system of any of Clauses 5-9, wherein: the working electrode of the analyte sensor is coupled with the first input of the first operational amplifier of the ASIC using a first bonding wire; and the reference electrode of the analyte sensor is coupled with the first input of the second operational amplifier of the ASIC using a second bonding wire.

[0184] Clause 11: The analyte sensor system of Clause 5-9, wherein: the working electrode of the analyte sensor is coupled with the first input of the first operational amplifier of the ASIC using a first electrical trace on the PCB; and the reference electrode of the analyte sensor is coupled with the first input of the second operational amplifier of the ASIC using a second electrical trace on the PCB.

[0185] Clause 12: The analyte sensor system of Clause 11, wherein at least the first electrical trace is surrounded on four sides by one or more guard band electrical traces.

[0186] Clause 13: The analyte sensor system of Clause 12, wherein the one or more operational amplifiers are further configured to output a second output signal, generated based on the first input signal, on the one or more guard band electrical traces.

[0187] Clause 14: The analyte sensor system of Clause 13, wherein the second output signal has a same gain as the first input signal.

[0188] Clause 15: The analyte sensor system of any of Clauses 12-14, wherein the one or more guard band electrical traces are configured to protect the first electrical trace from leakage currents.

[0189] Clause 16: The analyte sensor system of any of Clauses 1-15, wherein the one or more processors are further configured to power off the ASIC using one or more power switches during a first period of time in which the analyte concentration level ofthe user is not being measured.

[0190] Clause 17: The analyte sensor system of Clause 16, wherein the one or more processors are further configured to power on the ASIC using the one or more power switches during a second period of time in which the analyte concentration level of the user are to be measured.

[0191] Clause 18: The analyte sensor system of any of Clauses 16-17, wherein the one or more processors are configured to power on the ASIC using the one or more power switches based on a fixed periodicity or one or more trigger events.

[0192] Clause 19: The analyte sensor system of Clause 18, wherein the one or more trigger events are based on a temperature change or based on user input from a force sensor or accelerometer.

[0193] Clause 20: The analyte sensor system of any of Clauses 18-19, wherein the one or more processors are further configured to power off the ASIC using the one or more power switches after the analyte concentration level of the user has been determined.

[0194] Clause 21: The analyte sensor system of any of Clauses 1-20, wherein the analyte concentration level comprises at least one of a glucose concentration level, a sodium ion concentration level, a potassium ion concentration level, a hydrogen ion concentration level, a lithium ion concentration level, a magnesium ion concentration level, a calcium ion concentration level, a chloride ion concentration level, a sulfite ion concentration level, a sulfate ion concentration level, a manganese concentration level, a phosphate ion concentration level, an ammonium ion concentration level, a uric acid concentration level, a urea concentration level, a ketone concentration level, a concentration of lactate, or a concentration level of creatinine.

[0195] Clause 22: A method for performing analyte measurements by a wearable device, comprising: performing, by a transcutaneous analyte sensor, at least one potentiometric-based measurement of an analyte concentration level of a user of the wearable device; receiving, at one or more operational amplifiers of an application specific integrated circuit (ASIC) of the wearable device, a first input signal from a working electrode of the transcutaneous analyte sensor based on performing the at least one potentiometric-based measurement; receiving, at the one or more operational amplifiers of the ASIC, a second input signal from a reference electrode of the transcutaneous analyte sensor based on performing the at least one potentiometric-basedmeasurement, wherein the first input signal and the second input signal are associated with the analyte concentration level of the user; outputting, from the one or more operational amplifiers to an analog to digital converter (ADC) of the wearable device, an output signal representing a differential between the first input signal and second input signal; converting, by the ADC, the output signal to a digital signal; receiving, by one or more processors of the wearable device, the digital signal from the ADC and processing the digital signal to determine the analyte concentration level of the user, wherein the ASIC, the ADC, and the one or more processors are operatively coupled by a printed circuit board (PCB).

[0196] Clause 23: The method of Clause 22, further comprising: receiving and filtering, by a low pass filter (LPF) of the wearable device, the output signal; and providing the output signal to the ADC after the filtering.

[0197] Clause 24: The method of any of Clauses 22-23, further comprising applying an offset voltage to the second signal associated with the reference electrode.

[0198] Clause 25: The method of Clause 24, wherein the offset voltage comprises approximately 100 millivolts or more.

[0199] Clause 26: The method of any of Clauses 22-25, wherein: the working electrode is coupled with a first input of a first operational amplifier; the reference electrode is coupled with a first input of a second operational amplifier; and the method further comprises: amplifying, by the first operational amplifier, the first input signal; and outputting, by the first operational amplifier, the amplified first input signal to a first input of a third operational amplifier; amplifying, by the second operational amplifier, the second input signal; and outputting, by the second operational amplifier, the amplified second input signal to a second signal of the third operational amplifier.

[0200] Clause 27: The method of Clause 26, wherein the ASIC includes a plurality of input switches electrically coupled between the analyte sensor and the first inputs of the first and second operational amplifiers.

[0201] Clause 28: The method of Clause 27, further comprising operating the plurality of switches.

[0202] Clause 29: The method of Clause 28, wherein operating the plurality of switches comprises, during a first period of time in which the analyte concentration level of the user is not being measured, maintaining the plurality of switches in an open positionto electrically isolate the analyte sensor from the ASIC.

[0203] Clause 30: The method of Clause 29, wherein operating the plurality of switches further comprises, during a second period of time in which the analyte sensor system is configured to measure the analyte concentration level of the user: operating the plurality of switches such that the working electrode and reference electrode are shorted; and after a threshold amount of time that the working electrode and reference electrode have been shorted, operating the plurality of switches to: isolate the working electrode from the reference electrode; connect the working electrode to the first input of the first operational amplifier; and connect the reference electrode to the first input of the second operational amplifier.

[0204] Clause 31: The method of any of Clauses 26-30, wherein: the working electrode of the analyte sensor is coupled with the first input of the first operational amplifier of the ASIC using a first bonding wire; and the reference electrode of the analyte sensor is coupled with the first input of the second operational amplifier of the ASIC using a second bonding wire.

[0205] Clause 32: The method of any of Clauses 26-30, wherein: the working electrode of the analyte sensor is coupled with the first input of the first operational amplifier of the ASIC using a first electrical trace on the PCB; and the reference electrode of the analyte sensor is coupled with the first input of the second operational amplifier of the ASIC using a second electrical trace on the PCB.

[0206] Clause 33: The method of Clause 32, wherein at least the first electrical trace is surrounded on four sides by one or more guard band electrical traces.

[0207] Clause 34: The method of Clause 33, further comprising outputting, by the one or more operational amplifiers, a second output signal, generated based on the first input signal, on the one or more guard band electrical traces.

[0208] Clause 35: The method of Clause 34, wherein the second output signal has a same gain as the first input signal.

[0209] Clause 36: The method of any of Clauses 33-35, wherein the one or more guard band electrical traces are configured to protect the first electrical trace from leakage currents.

[0210] Clause 37: The method of any of Clauses 22-36, further comprising poweringoff the ASIC using one or more power switches during a first period of time in which the analyte concentration level of the user is not being measured.

[0211] Clause 38: The method of Clause 37, further comprising powering on the ASIC using the one or more power switches during a second period of time in which the analyte concentration level of the user are to be measured.

[0212] Clause 39: The method of any of Clauses 37-38, further comprising powering on the ASIC using the one or more power switches based on a fixed periodicity or one or more trigger events.

[0213] Clause 40: The method of Clause 39, wherein the one or more trigger events are based on a temperature change or based on user input from a force sensor or accelerometer.

[0214] Clause 41: The method of any of Clauses 39-40, further comprising powering off the ASIC using the one or more power switches after the analyte concentration level of the user has been measured.

[0215] Clause 42: The method of any of Clauses 22-41, wherein the analyte concentration level comprises at least one of a glucose concentration level, a sodium ion concentration level, a potassium ion concentration level, a hydrogen ion concentration level, a lithium ion concentration level, a magnesium ion concentration level, a calcium ion concentration level, a chloride ion concentration level, a sulfite ion concentration level, a sulfate ion concentration level, a manganese concentration level, a phosphate ion concentration level, an ammonium ion concentration level, a uric acid concentration level, a urea concentration level, a ketone concentration level, a concentration of lactate, or a concentration level of creatinine.

[0216] Clause 43: An apparatus, comprising: one or more processors configured to execute instructions stored on one or more memories and to cause the apparatus to perform a method in accordance with any combination of Clauses 22-42.

[0217] Clause 44: An apparatus, comprising means for performing a method in accordance with any combination of Clauses 22-42.

[0218] Clause 45: A non-transitory computer-readable medium comprising executable instructions that, when executed by one or more processors of an apparatus, cause the apparatus to perform a method in accordance with any combination of Clauses22-42.

[0219] Clause 46: A computer program product embodied on a computer-readable storage medium comprising code for performing a method in accordance with any combination of Clauses 22-42.Additional Considerations

[0220] In this document, the terms “computer program medium” and “computer usable medium” and “computer readable medium”, as well as variations thereof, are used to generally refer to transitory or non-transitory media. These and other various forms of computer program media or computer usable / readable media may be involved in carrying one or more sequences of one or more instructions to a processing device for execution. Such instructions embodied on the medium, may generally be referred to as “computer program code” or a “computer program product” or “instructions” (which may be grouped in the form of computer programs or other groupings). When executed, such instructions may enable a computing module, such as the SS 8, display device 150, circuitry related thereto, and / or a processor thereof or connected thereto to perform features or functions of the present disclosure as discussed herein (for example, in connection with methods described above and / or in the claims), including for example when the same is / are incorporated into a system, apparatus, device and / or the like.

[0221] Various embodiments have been described with reference to specific example features thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the various embodiments as set forth in the appended claims. The specification and figures are, accordingly, to be regarded in an illustrative rather than a restrictive sense. It will be appreciated that, for clarity purposes, the above description has described embodiments with reference to different functional units. However, it will be apparent that any suitable distribution of functionality between different functional units may be used without detracting from the invention. For example, functionality illustrated to be performed by separate computing devices may be performed by the same computing device. Likewise, functionality illustrated to be performed by a single computing device may be distributed amongst several computing devices. Hence, references to specific functional units are only to be seen as references to suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization.

[0222] Although described above in terms of various example embodiments and implementations, it should be understood that the various features, aspects and functionality described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described, but instead may be applied, alone or in various combinations, to one or more of the other embodiments of the present application, whether or not such embodiments are described and whether or not such features are presented as being a part of a described embodiment. Thus, the breadth and scope of the present application should not be limited by any of the above-described example embodiments.

[0223] Terms and phrases used in the present application, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. As examples of the foregoing: the term “including” should be read as meaning “including, without limitation” or the like; the term “example” is used to provide illustrative instances of the item in discussion, not an exhaustive or limiting list thereof; the terms “a” or “an” should be read as meaning “at least one,” “one or more” or the like; the term “set” should be read to include one or more objects of the type included in the set; and adjectives such as “conventional,” “traditional,” “normal,” “standard,” “known” and terms of similar meaning should not be construed as limiting the item described to a given time period or to an item available as of a given time, but instead should be read to encompass conventional, traditional, normal, or standard technologies that may be available or known now or at any time in the future. Similarly, the plural may in some cases be recognized as applicable to the singular and vice versa. Likewise, where this document refers to technologies that would be apparent or known to one of ordinary skill in the art, such technologies encompass those apparent or known to the skilled artisan now or at any time in the future.

[0224] The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent. The use of the term “module” does not imply that the components or functionality described or claimed as part of the module are all configured in a common package. Indeed, any or all of the various components of a module, whether control logic, circuitry, or other components, may be combined in a single package or separately maintained and may further be distributed in multiple groupings or packages or acrossmultiple locations.

[0225] Additionally, the various embodiments set forth herein are described in terms of example block diagrams, flow charts, and other illustrations. As will become apparent to one of ordinary skill in the art after reading this document, the illustrated embodiments and their various alternatives may be implemented without confinement to the illustrated examples. For example, block diagrams and their accompanying description should not be construed as mandating a particular architecture or configuration. Moreover, the operations and sub-operations of various methods described herein are not necessarily limited to the order described or shown in the figures, and one of skill in the art will appreciate, upon studying the present disclosure, variations of the order of the operations described herein that are within the spirit and scope of the disclosure.

[0226] It will be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can be implemented by execution of computer program instructions. These computer program instructions may be loaded onto a computer or other programmable data processing apparatus (such as a controller, microcontroller, microprocessor or the like) in a sensor electronics system to produce a machine, such that the instructions which execute on the computer or other programmable data processing apparatus create instructions for implementing the functions specified in the flowchart block or blocks. These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks presented herein.

[0227] It should be appreciated that all methods and processes disclosed herein may be used in any glucose or other analyte monitoring system, continuous or intermittent. It should further be appreciated that the implementation and / or execution of all methods and processes may be performed by any suitable devices or systems, whether local or remote.Further, any combination of devices or systems may be used to implement the present methods and processes.

[0228] In addition, the operations and sub-operations of methods described herein may be carried out or implemented, in some cases, by one or more of the components, elements, devices, modules, circuitry, processors, etc. of systems, apparatuses, devices, environments, and / or computing modules described herein and referenced in various of figures of the present disclosure, as well as one or more sub- components, elements, devices, modules, processors, circuitry, and the like depicted therein and / or described with respect thereto. In such instances, the description of the methods or aspects thereof may refer to a corresponding component, element, etc., but regardless of whether an explicit reference is made, one of skill in the art will recognize upon studying the present disclosure when the corresponding component, element, etc. may be used. Further, it will be appreciated that such references do not necessarily limit the described methods to the particular component, element, etc. referred to. Thus, it will be appreciated by one of skill in the art that aspects and features described above in connection with (sub-) components, elements, devices, modules, and circuitry, etc., including variations thereof, may be applied to the various operations described in connection with methods described herein, and vice versa, without departing from the scope of the present disclosure.

Claims

CLAIMS1. A method, performed at a wearable device, for performing analyte measurements, comprising: performing, by a transcutaneous analyte sensor of the wearable device, at least one potentiometric -based measurement of an analyte concentration level of a user of the wearable device; receiving, at one or more operational amplifiers of an application specific integrated circuit (ASIC) of the wearable device, a first input signal from a working electrode of the transcutaneous analyte sensor upon performing the at least one potentiometric-based measurement; receiving, at the one or more operational amplifiers of the ASIC, a second input signal from a reference electrode of the transcutaneous analyte sensor based on performing the at least one potentiometric-based measurement, wherein the first input signal and the second input signal are associated with the analyte concentration level of the user, wherein the first input signal includes a first noise component; outputting, from the one or more operational amplifiers to an analog to digital converter (ADC) of the wearable device, an output signal representing a differential between the first input signal and second input signal; converting, by the ADC, the output signal to a digital signal, wherein the output signal includes a second noise component that is less than the first noise component; and receiving, by one or more processors of the wearable device, the digital signal from the ADC and processing the digital signal to determine the analyte concentration level of the user, wherein the ASIC, the ADC, and the one or more processors are operatively coupled by a printed circuit board (PCB).

2. The method of claim 1, further comprising: receiving and filtering, by a low pass filter (LPF) of the wearable device, the output signal, wherein the LFP is configured to reduce the second noise component to be less than the first noise component; and providing the output signal to the ADC after the filtering.

3. The method of any one of claims 1-2, further comprising applying an offset voltage to the second signal associated with the reference electrode.

4. The method of claim 3, wherein the offset voltage comprises approximately 100 millivolts or more.

5. The method of any one of claims 1-4, wherein: the working electrode is coupled with a first input of a first operational amplifier; the reference electrode is coupled with a first input of a second operational amplifier; and the method further comprises: amplifying, by the first operational amplifier, the first input signal; and outputting, by the first operational amplifier, the amplified first input signal to a first input of a third operational amplifier; amplifying, by the second operational amplifier, the second input signal; and outputting, by the second operational amplifier, the amplified second input signal to a second signal of the third operational amplifier.

6. The method of claim 5, wherein: the ASIC includes a plurality of input switches electrically coupled between the transcutaneous analyte sensor and the first inputs of the first and second operational amplifiers; and the method further comprises operating the plurality of switches; operating the plurality of switches comprises, during a first period of time in which the analyte concentration level of the user is not being measured, maintaining the plurality of switches in an open position to electrically isolate the transcutaneous analyte sensor from the ASIC; and operating the plurality of switches further comprises, during a second period of time in which the transcutaneous analyte sensor system is configured to measure the analyte concentration level of the user: operating the plurality of switches such that the working electrode and reference electrode are shorted; and after a threshold amount of time that the working electrode and reference electrode have been shorted, wherein the working electrode and the referenceelectrode being shorted allows a charge build up between the working electrode the reference electrode to be reduced, operating the plurality of switches to: isolate the working electrode from the reference electrode; connect the working electrode to the first input of the first operational amplifier; and connect the reference electrode to the first input of the second operational amplifier.

7. The method of any one of claims 5-6, wherein: the working electrode of the transcutaneous analyte sensor is coupled with the first input of the first operational amplifier of the ASIC using a first bonding wire; and the reference electrode of the transcutaneous analyte sensor is coupled with the first input of the second operational amplifier of the ASIC using a second bonding wire.

8. The method of any one of claims 5-6, wherein: the working electrode of the transcutaneous analyte sensor is coupled with the first input of the first operational amplifier of the ASIC using a first electrical trace on the PCB; and the reference electrode of the transcutaneous analyte sensor is coupled with the first input of the second operational amplifier of the ASIC using a second electrical trace on the PCB.

9. The method of claim 8, wherein: at least the first electrical trace is surrounded on four sides by one or more guard band electrical traces; the method further comprises outputting, by the one or more operational amplifiers, a second output signal, generated based on the first output signal, on the one or more guard band electrical traces; the second output signal has a substantially similar gain as the first input signal; and one or more guard band electrical traces are configured to protect the first electrical trace from leakage currents, wherein the one or more guard band electrical traces are configured to reduce the second noise component to be less than the first noise component.

10. The method of any one of claims 1-9, further comprising: powering off the ASIC using one or more power switches during a first period of time in which the analyte concentration level of the user is not being measured; and powering on the ASIC using the one or more power switches during a second period of time in which the analyte concentration level of the user is to be measured.

11. The method of claim 10, further comprising: powering on the ASIC using the one or more power switches based on a fixed periodicity or one or more trigger events.

12. The method of claim 11, wherein the one or more trigger events are based on a temperature change or based on user input from a force sensor or accelerometer.

13. The method of any one of claims 11-12, further comprising powering off the ASIC using the one or more power switches after the analyte concentration level of the user has been determined.

14. The method of any one of claims 1-13, wherein the analyte concentration level comprises at least one of a glucose concentration level, a sodium ion concentration level, a potassium ion concentration level, a hydrogen ion concentration level, a lithium ion concentration level, a magnesium ion concentration level, a calcium ion concentration level, a chloride ion concentration level, a sulfite ion concentration level, a sulfate ion concentration level, a manganese concentration level, a phosphate ion concentration level, an ammonium ion concentration level, a uric acid concentration level, a urea concentration level, a ketone concentration level, a concentration of lactate, or a concentration level of creatinine.

15. A wearable device configured to perform a method for performing analyte measurements according to any one of claims 1-14.

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