WO2025264487A2

WO2025264487A2 - Reader device for displaying analyte data having short circuit detection and capable of detecting safety of charger device

Info

Publication number: WO2025264487A2
Application number: PCT/US2025/033498
Authority: WO
Inventors: Theodore J. KUNICH; Marc B. Taub; Namvar Kiaie
Original assignee: Abbott Diabetes Care Inc
Current assignee: Abbott Diabetes Care Inc
Priority date: 2024-06-21
Filing date: 2025-06-13
Publication date: 2025-12-26
Anticipated expiration: 2026-12-21
Also published as: WO2025264487A3

Abstract

A reader device for displaying analyte data includes a housing, a charging port configured to engage with a connector of a charging device, and a power source configured to be charged by the charging device. The reader devices includes communication circuitry for receiving analyte data from a sensor control device having an in vivo analyte sensor, and a display for displaying analyte data. The reader device includes a first temperature sensor configured to measure a first temperature of the charging port, and a second temperature sensor configured to measure an internal temperature within the housing. A processing device of the reader device receives the first and second temperatures, determines a difference between the first and second temperatures, and outputs an alert when the difference exceeds a temperature difference threshold.

Description

READER DEVICE FOR DISPLAYING ANALYTE DATA HAVING SHORT CIRCUIT DETECTION AND CAPABLE OF DETECTING SAFETY OF CHARGER DEVICE

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 63/662,530, filed June 21, 2024 entitled “Reader Device for Displaying Analyte Data and Having Short Circuit Detection,” and to U.S. Provisional Application No. 63/677,034, filed July 30, 2024 entitled “Reader Device for Displaying Analyte Data and Capable of Detecting Safety of Charger Device,” the disclosures of each of which applications are incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

[0002] Embodiments described herein relate to a reader device for displaying analyte data. Specifically, embodiments described herein relate to a reader device for displaying analyte data and that is configured to detect a short circuit at a charging port of the reader device. Further, embodiments described herein relate to a reader device configured to display analyte data and to detect whether a connected charging device is suitable for use with the reader device.

BACKGROUND

[0003] Analyte monitoring systems generally include an analyte sensor for monitoring analyte levels in the body of a user and a reader device in communication with the analyte sensor. The reader device may be a portable, hand-held device, such as a smartphone or a dedicated reader device provided by the analyte sensor manufacturer. The reader device receives analyte data from the analyte sensor and processes and displays the analyte data to the user. The reader device may display a current analyte level, an analyte trend, and a graph of analyte levels over time, among other metrics and information to help the user to manage analyte levels. In this way, the user can easily monitor analyte levels which may help to determine the analyte level response to various events, such as meals, medication doses, and exercise, among others. Monitoring analyte levels may be helpful with monitoring a disease, such as for users having diabetes, or to monitor health and wellness of a user.

SUMMARY OF THE INVENTION

[0004] Described herein is a reader device for displaying analyte data, the reader device includes a housing, a charging port arranged on the housing, wherein the charging port is configured to engage with a connector of a charging device, and a power source arranged within the reader device that is configured to be charged by the charging device when the charging device is engaged with the charging port. The reader device further includes communication circuitry for receiving analyte data from a sensor control device having an in vivo analyte sensor, and a display arranged on the housing for displaying at least a portion of the analyte data received from the sensor control device. The reader device includes a first temperature sensor configured to measure a first temperature of the charging port, a second temperature sensor configured to measure a second temperature, wherein the second temperature is an internal temperature within the housing, and a processing device in communication with the first and second temperature sensors and configured to detect a short circuit. The processing device is configured to receive the first temperature measured by the first temperature sensor, receive the second temperature measured by the second temperature sensor, calculate a difference between the first temperature and the second temperature, compare the difference to a temperature difference threshold, and output an alert when the difference exceeds the temperature difference threshold.

[0005] In any of the various embodiments described herein, the alert may include a notification output on the display of the reader device.

[0006] In any of the various embodiments described herein, the alert may include one or more of an audible alert or a vibratory alert.

[0007] In any of the various embodiments described herein, the processing device may be a comparator. The use of a low power device, such as a comparator, for detecting short circuits may help to conserve power.

[0008] In any of the various embodiments described herein, the processing device may be configured to receive the first and second temperatures at a predetermined sampling interval. In some embodiments, the predetermined sampling interval may be between 1 second and 300 seconds. In some embodiments, the predetermined sampling interval may be based on a thermal time constant of the first temperature sensor. As the short circuit detection consumes power, the sampling intervals described herein strike a balance between the need to monitor for a short circuit at a sufficient frequency while limiting power consumption.

[0009] In any of the various embodiments described herein, at least one of the first temperature sensor and second temperature sensor may be one of a thermistor, a thermocouple, a resistance temperature detector, a negative temperature coefficient element, a positive temperature coefficient element, or an active silicon temperature sensor. In any of the various embodiments described herein, the temperature difference threshold may be about 10°C.

[0010] In any of the various embodiments described herein, the temperature difference threshold may be dynamically determined by the reader device.

[0011] In any of the various embodiments described herein, the reader device may further include a processor coupled to the communication circuitry and to the display.

[0012] Described herein is a reader device for displaying analyte data, the reader device includes a housing, a charging port arranged on the housing, wherein the charging port is configured to engage with a connector of a charging device, and a power source arranged within the reader device configured to be charged by the charging device when the charging device is engaged with the charging port. The reader device includes communication circuitry for receiving analyte data from a sensor control device having an in vivo analyte sensor, and a display arranged on the housing for displaying at least a portion of the analyte data received from the sensor control device. The reader device further includes a first temperature sensor configured to measure a first temperature of the charging port, a second temperature sensor configured to measure a second temperature, wherein the second temperature is an internal temperature within the housing, and a processing device in communication with the first and second temperature sensors. The processing device is configured to determine a first rate of change of the first temperature, determine a second rate of change of the second temperature, calculate a difference between the first rate of change and the second rate of change, compare the difference between the first rate of change and the second rate of change to a rate of change difference threshold, and output an alert when the difference between the first rate of change and the second rate of change exceeds the rate of change difference threshold.

[0013] In any of the various embodiments described herein, the alert may include a notification output on the display of the reader device.

[0014] In any of the various embodiments described herein, the processing device may include a comparator. The use of a low power device, such as a comparator, for detecting short circuits may help to conserve power.

[0015] In any of the various embodiments described herein, the processing device may be further configured to determine the first and second rates of change at a predetermined sampling interval. In some embodiments, the predetermined sampling interval may be based on a thermal time constant of the first temperature sensor.

[0016] Some embodiments described herein relate to a method for detecting a short circuit at a charging port of a reader device configured to display analyte data, the method including receiving, by communication circuitry of the reader device, the analyte data from a sensor control device having an in vivo analyte sensor, displaying, by a display of the reader device, at least a portion of the analyte data received from the sensor control device, and charging a power source of the reader device when a connector of a charging device is engaged with a charging port of the reader device. The method further includes measuring, by a first temperature sensor of the reader device, a first temperature of the charging port of the reader device when the charging device is engaged with the charging port, and measuring, by a second temperature sensor of the reader device, a second temperature, wherein the second temperature is an internal temperature within the housing. The method further includes calculating, by a processing device of the reader device, a difference between the first temperature and the second temperature, comparing, by the processing device, the difference to a temperature difference threshold, and outputting, by the reader device, an alert when the difference exceeds the temperature difference threshold.

[0017] In any of the various embodiments described herein, the method may include measuring the first and second temperatures at a predetermined sampling interval.

[0018] In any of the various embodiments described herein, outputting the alert may include outputting a notification on the display of the reader device. [0019] Some embodiments described herein relate to a method for detecting a short circuit at a charging port of a reader device configured to display analyte data, the method includes receiving, by communication circuitry of the reader device, the analyte data from a sensor control device having an in vivo analyte sensor; and displaying, by a display of the reader device, at least a portion of the analyte data received from the sensor control device. The method includes charging a power source of the reader device when a connector of a charging device is engaged with a charging port of the reader device; measuring, by a first temperature sensor of the reader device, a first temperature of the charging port of the reader device; and measuring, by a second temperature sensor of the reader device, a second temperature, wherein the second temperature is an internal temperature within the housing. The method includes determining, by a processing device, a first rate of change of the first temperature; determining, by the processing device, a second rate of change of the second temperature; and calculating, by the processing device, a difference between the first rate of change and the second rate of change; comparing, by the processing device, the difference to a rate of change difference threshold; and outputting, by the reader device, an alert when the difference between the first rate of change and the second rate of change exceeds the rate of change difference threshold.

[0020] In any of the various embodiments described herein, the first and second temperatures may be measured at a predetermined sampling interval.

[0021] In any of the various embodiments described herein, outputting the alert may include outputting a notification on the display of the reader device.

[0022] Described herein is a reader device for displaying analyte data collected by an in vivo analyte sensor, the reader device includes a display for displaying the analyte data, a rechargeable power source, charger testing circuitry to determine if a charging device to charge the rechargeable power source is suitable for use with the reader device, and a measuring device in communication with the charger testing circuitry and configured to measure a voltage in the charger testing circuitry when a test load is supplied to the charging device. The charger testing circuitry includes a charger input to receive the charging device, and a control input to cause a test load to be applied to the charging device connected to the charger input. When the measured voltage is above a threshold voltage level, the reader device can provide a notification to a user indicating that the charging device is not suitable for use. Also described is a reader device for displaying analyte data collected by an in vivo analyte sensor includes a display for displaying the analyte data, a rechargeable power source, a charger input to receive a charging device that charges the rechargeable power source, and charger testing circuitry to determine if the charging device is suitable for use with the reader device. The charger testing circuitry includes a control input to cause a test load to be applied to the charging device connected to a charger input. The reader device also includes a measuring device in communication with the charger testing circuitry to measure a voltage in the charger testing circuitry when the test load is supplied to the charging device. When the measured voltage is above a threshold voltage level, the reader device provides a notification to a user indicating that the charging device is not suitable for use.

[0023] In any of the various embodiments described herein, when the measured voltage is below the threshold voltage level, the reader device may display the analyte data.

[0024] In any of the various embodiments described herein, the charging device may be a USB charger, and the charger input may be a USB input.

[0025] In any of the various embodiments described herein, the charger input can receive a 5 V input.

[0026] In any of the various embodiments described herein, the test load can provide a current to the charging device in a range of 650 mA to 1000 mA.

[0027] In any of the various embodiments described herein, the threshold voltage level may be around 0 V, or may be up to 4V, for example 0.5V, IV, 2V, 3V, or 4V.

[0028] In any of the various embodiments described herein, the control input may cause the test load to be applied for a predetermined time period, for example up to 5 seconds.

[0029] In any of the various embodiments described herein, the control input may cause the test load to be applied by generating a resistance load in the charger testing circuitry.

[0030] In some embodiments described herein, the measuring device can measure the voltage across the resistance load.

[0031] In any of the various embodiments described herein, when the measured voltage is above a threshold voltage level, the reader device can prevent the charging device from charging the rechargeable power source.

[0032] In any of the various embodiments described herein, the charger testing circuitry may further include one or more field effect transistors. [0033] In some embodiments described herein, the charger testing circuitry may include a first field effect transistor and a second field effect transistor. The first field effect transistor and the second field effect transistor may be inactive before the test load is applied and are activated via the control input.

[0034] In some embodiments described herein, the first field effect transistor may be in electrical communication with the charger input and with a first resistor. The first resistor may be positioned between the first field effect transistor and the second field effect transistor.

[0035] In some embodiments described herein, the measuring device can measure the voltage in the charger testing circuitry between the first field effect transistor and the first resistor.

[0036] In some embodiments described herein, the reader device may further include a second resistor positioned between the first resistor and the second field effect transistor. The measuring device can measure the voltage in the charger testing circuitry between the first resistor and the second resistor.

[0037] In any of the various embodiments described herein, the notification may include one or more of a visual notification provided via the display of the reader device or an audible notification provided by the reader device.

[0038] In any of the various embodiments described herein, the measuring device may be a microcontroller.

[0039] In some embodiments described herein, the microcontroller may include an analog to digital converter.

[0040] In any of the various embodiments described herein, the measuring device may be a comparator.

[0041] Some embodiments described herein relate to an analyte monitoring system including the reader device in any of the various embodiments described herein and an in vivo analyte monitoring device. The analyte monitoring device includes an analyte sensor including a first portion configured to be arranged above a skin surface and a second portion configured to be arranged below the skin surface and in contact with a bodily fluid of the user to sense analyte levels, and sensor electronics coupled to the first portion of the analyte sensor. The sensor electronics includes a processor and wireless communication circuitry for wirelessly communicating analyte data to the reader device. [0042] Some embodiments described herein relate to a method of determining if a charging device is suitable for use with a reader device of an analyte monitoring system, the method includes receiving the charging device at the charging input of the reader device. The reader device includes a rechargeable power source charged by the charging device. The reader device applies a test load via a control input of charger testing circuitry of the reader device to the charging device, and measures a voltage in the charger testing circuitry using a measuring device of the reader device when the test load is provided to the charging device. The reader device outputs a notification when the measured voltage is above a threshold voltage level indicating that the charging device is not suitable for use.

[0043] In any of the various embodiments described herein, if the measured voltage is at or below the threshold voltage level, the method may further include displaying analyte data on the display of the reader device, wherein the analyte data is collected by an in vivo analyte sensor.

[0044] In any of the various embodiments described herein, if the measured voltage is at or below the threshold voltage level, the method may further include charging the rechargeable power source of the reader device.

[0045] In any of the various embodiments described herein, the threshold voltage level may be 0 V, or may be up to 4V, for example 0.5V, IV, 2V, 3V or 4V.

[0046] In any of the various embodiments described herein, providing the test load may include providing a current to the charging device in a range of 650 mA to 1000 mA.

[0047] In any of the various embodiments described herein, outputting the notification may include displaying a visual notification on the display of the reader device.

[0048] In any of the various embodiments described herein, the voltage may be measured by a microcontroller of the reader device.

[0049] In any of the various embodiments described herein, the test load may be applied for a predetermined time period, for example up to 5 seconds.

[0050] In any of the various embodiments described herein, applying the test load may include generating a resistance load in the charger testing circuitry.

[0051] In some embodiments described herein, measuring a voltage in the charger testing circuitry may include measuring the voltage across the resistance load. [0052] In any of the various embodiments described herein, the method may further include preventing the charging device from charging the rechargeable power source when the measured voltage is above a threshold voltage level.

[0053] In any of the various embodiments described herein, the charger testing circuitry may include a first field effect transistor and a second field effect transistor.

[0054] In any of the various embodiments described herein, the first field effect transistor may be in electrical communication with the charger input and a first resistor positioned between the first field effect transistor and the second field effect transistor. The voltage may be measured between the first field effect transistor and the first resistor.

BRIEF DESCRIPTION OF THE FIGURES

[0055] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present disclosure and, together with the description, further serve to explain the principles thereof and to enable a person skilled in the pertinent art to make and use the same.

[0056] FIG. 1 shows an analyte monitoring system according to an embodiment.

[0057] FIG. 2A shows a block diagram of a sensor control device according to an embodiment.

[0058] FIG. 2B shows a block diagram of a sensor control device according to another embodiment.

[0059] FIG. 3 shows a block diagram of a reader device according to an embodiment.

[0060] FIG. 4 shows a schematic diagram of a reader device and a charging device according to an embodiment.

[0061] FIG. 5 shows an exemplary method of detecting a short circuit according to an embodiment.

[0062] FIG. 6 shows an exemplary method of detecting a short circuit according to an embodiment.

[0063] FIG. 7 shows an exemplary notification according to an embodiment.

[0064] FIG. 8 shows a block diagram of a reader device according to an embodiment.

[0065] FIG. 9 shows a schematic diagram of a reader device and a charging device according to an embodiment. [0066] FIG. 10 shows a schematic diagram of charger testing circuity according to an embodiment.

[0067] FIG. 11 shows a schematic diagram of charger testing circuity according to an alternate embodiment.

[0068] FIG. 12 shows an exemplary method of detecting safety of a charging device connected to a reader device according to an embodiment.

[0069] FIG. 13 shows an exemplary notification according to an embodiment.

DETAILED DESCRIPTION

[0070] Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the claims.

[0071] As used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

[0072] A reader device of an analyte monitoring system may include a rechargeable power source. The reader device may include a charging port for connecting a charging device to the reader device to allow for recharging of the power source. Safety mechanisms are needed to ensure that the charging device is suitable for use with the reader device. If the charging device is not suitable for use with the reader device, such as if the charging device has too much power (e.g., too high of voltage) for the reader device, there is a risk of damage to the device and there is a risk that a short circuit may occur. Even if the charging device is compatible with the reader device, a short circuit may occur if there is debris the charging port, among other causes. A short circuit can result in excess generation of heat that can damage or destroy the reader device or the charging device and may cause harm to the user.

[0073] Accordingly, a reader device with safety mechanisms to ensure safe charging of the reader device is provided herein. The reader device may include means for detecting that a charging device is compatible for use with the reader device. The reader device may alternately or additionally include means for detecting a short circuit at the charging port. [0074] As smartphones and other reader devices have become more sophisticated and complex, the power requirements of such devices has increased. As a result, charging devices may supply a high amount of current to the reader device that can potentially lead to a destructive thermal event, such as a meltdown or fire, without exceeding the operating limits of the power adapter of the charging device.

[0075] A short circuit may occur at the connection between a charging device and a reader device. For example, foreign matter, such as dust or other debris may accumulate in the charging port over time and can create a short circuit when a charging cable is engaged with the charging port. Existing reader devices are unable to detect a short circuit at the interface of the charging port with the connector as the short circuit is occurring external to the reader device’s circuitry. The charging cable is also not configured to detect a short circuit at the charging port. A power adapter of the charging cable is arranged at the interface of the wall outlet and the charging cable, and the power adapter is not capable of detecting a short circuit at the interface of the charging cable and reader device.

[0076] As a result, there is a risk of harm to the user if a short circuit occurs at the charging port, and there is currently no mechanism for detecting the short circuit or alerting the user. If a short circuit occurs, the reader device or charging cable may rapidly generate heat and become extremely hot. The high temperatures can result in damage to the reader device, cable, or both, and can result in a fire, and the heat or fire can harm the user, such as by causing burns.

[0077] Described herein is a reader device for an analyte monitoring system that is configured to detect a short circuit at a charging port of the reader device. The reader device may include a short circuit detection assembly configured to detect a short circuit. The reader device is configured to output a notification when a short circuit is detected. The reader device may prevent further operation of the reader device, or may prevent display of analyte data when a short circuit is detected. This may help to ensure the user addresses the short circuit condition.

[0078] The reader device may include a first temperature sensor configured to measure a temperature of the charging port. The reader device may determine a short circuit based at least in part on the temperature of the charging port. The reader device may determine a short circuit based on comparison of the temperature of the charging port, the rate of change of the temperature of the charging port, or both to one or more thresholds. The thresholds may be predetermined or may be dynamically determined during use of the reader device. The thresholds may be unique to each reader device.

[0079] The reader device may further include a second temperature sensor configured to measure a second temperature. The second temperature sensor may measure a second temperature that is an internal temperature of the reader device and is configured to serve as a reference temperature measurement. The second temperature sensor is arranged remotely from the first temperature sensor and charging port such that an increase in temperature of the charging port does not impact, or minimally impacts, the second temperature measured by the second temperature sensor.

[0080] A short circuit can be detected by comparing the first and second temperatures. If a difference between the first and second temperatures exceeds a temperature difference threshold, an output is provided by the reader device to alert the user of the potential short circuit. Alternately, if the first temperature exceeds the second temperature by a predetermined percentage, an output is provided by the reader device to alert the user of the potential short circuit.

[0081] A short circuit can be detected by calculating a first rate of change of the first temperature and a second rate of change of the second temperature. If a difference in the first and second rate of change exceeds a rate of change threshold, an output is provided by the reader device to alert the user of the potential short circuit. If the first rate of change exceeds the second rate of change by a predetermined percentage, an output is provided by the reader device to alert the user of the potential short circuit.

[0082] FIG. l is a conceptual diagram depicting an exemplary embodiment of an analyte monitoring system 100 that includes a sensor applicator 150, a sensor control device 102, and a reader device 200. Sensor applicator 150 can be used to deliver sensor control device 102 to a monitoring location on a user's skin where an in vivo analyte sensor 104 is maintained in position for a period of time by an adhesive patch 105. Sensor control device 102 is further described in FIGS. 2A and 2B, and can communicate with reader device 200 via a communication path 140 using a wired or wireless technique. Example wireless protocols include Bluetooth, Bluetooth Low Energy (BLE, BTLE, Bluetooth SMART, etc.), Near Field Communication (NFC) and others. Users can view and use applications installed in memory on reader device 200 using display 220 (which, in many embodiments, can comprise a touchscreen). An input component 230 can be arranged on housing 210. A power source of reader device 200 can be recharged using charging port 250. While only one reader device 200 is shown, sensor control device 102 can communicate with multiple reader devices 200. Each of the reader devices 200 can communicate and share data with one another. More details about reader device 200 are set forth with respect to FIG. 3 below.

[0083] Reader device 200 can communicate with local computer system 170 via a communication path 141 using a wired or wireless communication protocol. Local computer system 170 can include one or more of a laptop, desktop, tablet, smartphone, set-top box, video game console, or other computing device and wireless communication can include any of a number of applicable wireless networking protocols including Bluetooth, Bluetooth Low Energy (BTLE), Wi-Fi or others. Local computer system 170 can communicate via communications path 143 with a network 190 similar to how reader device 200 can communicate via a communications path 142 with network 190, by a wired or wireless communication protocol as described previously. Network 190 can be any of a number of networks, such as private networks and public networks, local area or wide area networks, and so forth. A trusted computer system 180 can include one or more servers and can provide authentication services and secured data storage and can communicate via communications path 144 with network 190 by wired or wireless techniques.

[0084] FIGS. 2A and 2B are block diagrams depicting example embodiments of sensor control devices 102 having in vivo analyte sensors 104 and sensor electronics 160 (including analyte monitoring circuitry) that can have the majority of the processing capability for rendering end-result data suitable for display to the user. In FIG. 2A, a single semiconductor chip 161 is depicted that can be a custom application specific integrated circuit (ASIC). Shown within ASIC 161 are certain high-level functional units, including an analog front end (AFE) 162, power management (or control) circuitry 164, processor 166, and communication circuitry 168 (which can be implemented as a transmitter, receiver, transceiver, passive circuit, or otherwise according to the communication protocol). In this embodiment, both AFE 162 and processor 166 are used as analyte monitoring circuitry, but in other embodiments either circuit can perform the analyte monitoring function. Processor 166 can include one or more processors, microprocessors, controllers, and/or microcontrollers, each of which can be a discrete chip or distributed amongst (and a portion of) a number of different chips.

[0085] A memory 163 is also included within ASIC 161 and can be shared by the various functional units present within ASIC 161, or can be distributed amongst two or more of them. Memory 163 can also be a separate chip. Memory 163 can be volatile and/or nonvolatile memory. In this embodiment, ASIC 161 is coupled with power source 172, which can be a battery, or the like. AFE 162 interfaces with in vivo analyte sensor 104 and receives measurement data therefrom and outputs the data to processor 166 in digital form, which in turn processes the data to arrive at the end-result glucose discrete and trend values, etc. This data can then be provided to communication circuitry 168 for sending, by way of antenna 171, to reader device 200, for example, where minimal further processing is needed by the resident software application to display the data.

[0086] FIG. 2B is similar to FIG. 2A but instead includes two discrete semiconductor chips 161 and 174, which can be packaged together or separately. Here, AFE 162 is resident on ASIC 161. Processor 166 is integrated with power management circuitry 164 and communication circuitry 168 on chip 174. AFE 162 includes memory 163 and chip 174 includes memory 165, which can be isolated or distributed within. In one example embodiment, AFE 162 is combined with power management circuitry 164 and processor 166 on one chip, while communication circuitry 168 is on a separate chip. In another example embodiment, both AFE 162 and communication circuitry 168 are on one chip, and processor 166 and power management circuitry 164 are on another chip. It should be noted that other chip combinations are possible, including three or more chips, each bearing responsibility for the separate functions described, or sharing one or more functions for fail-safe redundancy.

[0087] FIG. 3 is a block diagram depicting an example embodiment of a reader device 200. Reader device 200 may include a housing having a display 220. Reader device 200 may include one or more input components 230, such as for receiving user input. Reader device 200 may include one or more processors, and processors may be coupled to memory. Reader device 200 may include a processing core 206 including a communications processor 222 coupled with first memory 223 and an applications processor 224 coupled with second memory 225 as shown in FIG. 3. Also included can be separate memory 239. Reader device 200 may include communication circuitry for receiving analyte data from sensor control device 102, or for communicating with other components of analyte monitoring system 100, such as local computer system 170, trusted computer system 180, or network 190. The communication circuitry may include a transceiver, such as a RF transceiver 228 with antenna 229, and/or a multi-functional transceiver 232 which can communicate over one or more of Wi-Fi, NFC, Bluetooth, BTLE, and GPS with an antenna 234. Reader device 200 may include a power source 226, and may further include a power management module 238. A charging port for charging power source 226 may be in electrical communication with power source 226 and/or power management module 238. As understood by one of skill in the art, these components are electrically and communicatively coupled in a manner to make a functional device.

[0088] Reader device 200 may be configured to perform short circuit detection. Reader device 200 may also be configured to determine if a charging device is suitable for use with the reader device, as further described herein. Instructions for short circuit detection may be stored in a memory of reader device, e.g., one or more of memory 223, 225, 239. When executed by a processing device, reader device 200 is configured to perform a series of steps to detect a short circuit and to alert the user to the short circuit condition as described herein. Components for detecting a short circuit may be referred to herein as a short circuit detection assembly 261. Short circuit detection assembly 261 may include one or more temperature sensors. Short circuit detection assembly 261 may further include a processing device 270 for comparing the measured temperature or temperatures to one another and/or to temperature thresholds.

[0089] FIG. 3 shows a short circuit detection assembly 261 having a processing device 270 in communication with first and second temperature sensors 260, 262. Processing device 270 may determine a difference between a measured temperature and a threshold. Processing device 270 may determine a difference between first and second temperatures measured by first and second temperature sensors 260, 262, respectively. Processing device 270 may alternately or additionally determine a rate of change of the first temperature, a rate of change of the second temperature, and a difference between the first and second rates of change. Processing device 270 may be a low-power device, such as a comparator. The use of a separate, low power device, such as a comparator for detecting short circuits may help to conserve power relative to using the processors 222, 224 of reader device 200 for short circuit detection, as processors 222, 224 of reader device 200 may have greater power consumption. Alternatively, one or both of processors 222 or 224 may perform short circuit detection. The use of processor(s) 222, 224 for short circuit detection may help to reduce the number of components and to simplify construction and manufacturing of reader device 200.

[0090] Reader device 200 is configured to communicate with a sensor control device 102. Sensor control device 102 may include an in vivo analyte sensor 104, such as an in vivo glucose sensor, as described herein. However, in other embodiments, one or more analytes may be measured by the in vivo analyte sensor, such as one or more of glucose, ketones, lactate, or alcohol. Other analytes that may be monitored with system 100 include, but are not limited to, acetyl choline, amylase, bilirubin, cholesterol, chorionic gonadotropin, glycosylated hemoglobin (HbAlc), creatine kinase (e.g., CK-MB), creatine, creatinine, DNA, fructosamine, glucose, glucose derivatives, glutamine, growth hormones, hormones, ketones, ketone bodies, lactate, peroxide, prostate-specific antigen, prothrombin, RNA, thyroid stimulating hormone, and troponin. The concentration of drugs, such as, for example, antibiotics (e.g., gentamicin, vancomycin, and the like), digitoxin, digoxin, drugs of abuse, theophylline, and warfarin, may also be monitored. When monitoring more than one analyte, the analytes may be monitored at the same or different times.

[0091] Reader device 200 may receive data from sensor control device 102, such as raw or processed analyte data. Reader device 200 may determine and/or display analyte metrics based on the received analyte data. Reader device 200 may use artificial intelligence, such as machine learning, e.g., deep learning, to analyze the received analyte data. Artificial intelligence may be used to detect patterns in the user’s analyte data, predict future glucose levels, predict extreme glucose events such as episodes of hypoglycemia or hyperglycemia, identify lifestyle events such as meals, medication dose administration, or exercise, or to generate recommendations to improve control of glucose levels, among other functions.

[0092] Display 220 of reader device 200 may display analyte data and other information. Display 220 may present a graphical user interface (GUI). Reader device 200 may display at least a portion of the analyte data received from the in vivo analyte sensor. Reader device 200 may display a plot of analyte levels over time based on received analyte data. The plot of analyte levels may be updated in real time as analyte data is received by reader device 200. Reader device 200 may display a current analyte level, and/or an analyte trend level. Reader device 200 may output alerts. Alerts may correspond to an analyte level condition, such as a high glucose level, a low glucose level, or a very low glucose level, among others. The alerts may be based on one or more analyte level thresholds which may be predetermined or adjustably set by the user or by a healthcare professional. Alerts may also correspond to system conditions, such as a temperature of the sensor, a communication error, a battery error, or an error related to sensor accuracy, among others.

[0093] As shown in FIG. 4, reader device 200 includes a housing 210 and a display 220 arranged on housing 210. Display 220 may include a liquid crystal display (LCD), a light emitting diode (LED) display, or an e-ink display, and may be a touchscreen display that is configured to receive user input, among other types of displays. Reader device 200 may further include one or more additional or alternate input components 230 for receiving user input, such as one or more of buttons, keys, a scroll wheel, or a touch pad, among others.

[0094] Reader device 200 may include a test strip port 240 for receiving an analyte test strip 245 carrying bodily fluid of the user, which can be analyzed to determine the user's analyte level, such as the user’s blood sugar level or ketone level, among other analytes.

[0095] Reader device 200 includes a charging port 250 configured to be engaged with a connector 310 of a charging device 300. A power source of reader device 200 is configured to be charged by charging device 300 when charging device 300 is engaged with charging port 250. Charging device 300 may include, for example, a cable 320 having a first end with a connector 310 to be removably engaged with charging port 250, and a second end having a power adapter 330 for connection to an electrical outlet 400. Connector 310 may be received within charging port 250, and connector 310 and charging port 250 may be configured to mate, such as by a plug and socket or malefemale type connection. However, it is understood that other types of charging devices 300 may be used with reader device 200 consistent with the disclosure herein, such as a charging device that includes an external power source (e.g., an external battery pack or power bank), a cable connected to another electronic device, such as a laptop, such that reader device 200 is charged by the electronic device, among others. In some embodiments, charging port 250 is a USB port, such as USB-C or micro-USB port. However, charging port 250 may be any of various other types of ports known in the art for receiving power from a charging device.

[0096] Reader device 200 may be configured to detect a short circuit at charging port 250. Reader device 200 includes a first temperature sensor 260 configured to measure a temperature of charging port 250. First temperature sensor 260 may directly contact charging port 250. First temperature sensor 260 may be thermally connected to charging port 250. First temperature sensor 260 may be a thermistor. In alternate embodiments, first temperature sensor 260 may be a thermocouple, or a resistance temperature detector (RTD), negative temperature coefficient (NTC) element, positive temperature coefficient (PTC) element, or active silicon temperature sensor, among other types of sensors.

[0097] Reader device 200 may further include a second temperature sensor 262. Second temperature sensor 262 is configured to measure a second temperature. Second temperature sensor 262 may be a thermistor, or alternatively may be a thermocouple, a resistance temperature detector (RTD), negative temperature coefficient (NTC) element, positive temperature coefficient (PTC) element, or active silicon temperature sensor, among other types of sensors. The second temperature is used as a reference temperature. Second temperature sensor 262 may be configured to detect an internal temperature within housing 210 of reader device 200. Second temperature sensor 262 may be configured to detect an ambient temperature. Second temperature sensor 262 may be thermally isolated from first temperature sensor 260 such that the second temperature measured by second temperature sensor 262 is not affected or is minimally affected by a change in temperature of the charging port 250. Accordingly, if temperature of charging port 250 increases, such as due to a short circuit, first temperature sensor 260 detects the increase in temperature of the charging port 250 and second temperature measured by second temperature sensor 262 remains unchanged. Second temperature sensor 262 may be arranged at a location in or on housing 210 of reader device 200 that is remote from first temperature sensor 260. In some embodiments, first temperature sensor 260 may be arranged on a first side 211 of housing 210 whereas second temperature sensor 262 is arranged on an opposing, second side 213 of housing 210. However, second temperature sensor 262 may be arranged on various portions of housing 210. [0098] In normal operation of reader device 200, when a short circuit is not present, the temperatures measured by first and second temperature sensors 260, 262 are equal or nearly equal. However, when a short circuit occurs at charging port 250, the first temperature as measured by first temperature sensor 260 increases. As second temperature sensor 262 is remote from, or thermally isolated from first temperature sensor 260, second temperature remains largely unaffected by the temperature increase at charging port 250. Accordingly, the difference in the first and second temperatures may be indicative of a short circuit at charging port 250.

[0099] A method of detecting a short circuit 500 according to an embodiment is shown in FIG. 5. A first temperature of charging port is measured 510. First temperature may be measured by first temperature sensor. A second temperature of reader device is measured 520. Second temperature may be measured by a second temperature sensor. First and second temperatures may be measured at substantially the same time, such that the first and second temperatures are measured within 1 second of one another, 0.5 seconds, or 0.25 seconds. A temperature difference between the first and second temperatures is calculated 530. Temperature difference may be calculated by a processing device, such as a comparator. The temperature difference is compared to a temperature difference threshold 540. If the temperature difference exceeds the temperature difference threshold, reader device outputs an alert to notify the user of the potential short circuit condition 550.

[0100] The temperature difference threshold may be a predetermined or fixed value. For example, the temperature difference threshold may be at least 10°C, in a range of 10°C to 20°C, and may be, for example, 10°C, 15°C, or 20°C. Reader device may repeat the method of measuring the first and second temperatures and comparing the difference to a temperature difference threshold at a predetermined interval. In some embodiments, reader device may only monitor for and detect short circuits when a charging device is connected to charging port. In such embodiments, reader device detects connection of charging device by means other than the presence of power, as a short circuit may prevent the reader device from detecting that the charging device is connected. In such embodiments, reader device may have a connector that is not USB type or that is a modified USB-type connector. In an alternate embodiment, a short circuit is determined based on a relative proportion or percentage of the first temperature to the second temperature. For example, the threshold for detection of a short circuit may be based on the first temperature being a set percentage (e.g., 10%, 20%, 25%) greater than the second temperature.

[0101] A rate of change of the first temperature may also be indicative of a short circuit. The rate of change of the first temperature may be compared to a rate of change threshold. The rate of change threshold may be predetermined. Alternately, a short circuit may be detected by comparing the rate of change of the first temperature to a second rate of change of the second temperature. Comparing the first rate of change to the second rate of change may be beneficial to prevent falsely detecting a short circuit due to a high rate of change of the first temperature alone. For example, if the reader device is outside in the sun, the first temperature may change at a relatively fast rate due to the sun and not due to a short circuit. However, if a second temperature within the housing is also measured, the second temperature would change at the same or a similar rate if the temperature change is due to heating by the sun. If the rate of change of the first temperature is greater than the rate of change of the second temperature, then the heating may not be solely due to heating by the sun and may be due to a short circuit condition at the charging port.

[0102] An exemplary method for detecting a short circuit 600 according to an embodiment is shown in FIG. 6. A first rate of change of first temperature of charging port may be calculated 610. First temperature sensor may measure first temperature and processing device in communication with first temperature sensor may calculate the first rate of change. A second rate of change of second temperature may also be calculated 620. Second temperature sensor may measure second temperature and processing device may calculate the second rate of change. The processing device may determine a rate of change in the first or second temperature based on two or more temperature measurements from the corresponding temperature sensor. The rate of change may be based on the rate of change over a predetermined period of time. A difference between the first and second rates of change may be calculated 630. The difference between the first and second rates of change is compared to a rate of change difference threshold 640. If the difference exceeds the rate of change difference threshold, reader device outputs an alert to notify the user of the potential short circuit condition 650.

[0103] The rate of change difference threshold may be predetermined. For example, the rate of change difference threshold may be predetermined amount that is at least 0.033°C/second, and the rate of change difference threshold may be in a range of 0.033°C/second to l°C/second. For example, the rate of change difference threshold may be an increase in temperature of 10°C in a 5 minute period. In an alternate embodiment, the threshold for detection of a short circuit is not based on a difference between the first and second rate of change and is instead based on a relative proportion or percentage of the first rate of change to the second rate of change. For example, the threshold may be based on the rate of change of the first temperature being a set percentage (e.g., 10%, 20%, 25%) greater than the rate of change of the second temperature.

[0104] The threshold for detecting a short circuit may be a fixed or constant value. In some embodiments, however, the threshold for detecting a short circuit may be dynamically determined during use of reader device 200, such that the threshold may change during use of reader device 200. In such embodiments, the threshold may be based at least in part on second temperature measured by second temperature sensor 262. Reader device 200 may have a predetermined operating range of temperatures. The predetermined operating range of temperatures may include a minimum operating temperature and a maximum operating temperature. For example, the range of operating temperatures of reader device 200 may be about 10°C to about 45°C. Reader device 200 may have a default temperature difference threshold for detection of a short circuit, and the default temperature difference threshold may decrease as second temperature increases toward the maximum operating temperature. For example, if the default temperature difference threshold is 10°C when second temperature is 30°C, the temperature difference threshold may decrease to 5°C when the second temperature is elevated and approaches the maximum operating temperature, for example, 40°C. As the temperature of the reader device is already elevated, in order to prevent a potential short circuit from increasing the temperature above the maximum operating temperature, the temperature difference threshold is decreased. In some embodiments, the temperature difference threshold may be decreased proportionally with the increase to second temperature. In some embodiments, the temperature difference threshold may be based on a series of predetermined temperature ranges or bins, e.g., temperature difference threshold has a first value when second temperature is in a first range of temperatures, temperature difference threshold has a second value when second temperature is in a second range of temperatures, etc. [0105] As a short circuit condition may occur and escalate rapidly, there is a need to frequently check for a potential short circuit condition before overheating and damage occurs. Further, the short circuit condition needs to be detected in sufficient time in advance of a dangerous condition occurring to provide the user with sufficient time to intervene and take corrective action, such as by disconnecting the charging device from the reader device. While it is desirable to frequently check for a short circuit, monitoring for the short circuit condition consumes power, and thus it is necessary to balance the need to monitor for a short circuit at a sufficient frequency and to limit power consumption. In order to balance the need to monitor for a short circuit sufficiently frequently while limiting power consumption, the sampling rate may be based on the thermal time constant of the first temperature sensor, the second temperature sensor, or of the reader device. The sampling rate may be at least 1 second, no more than 300 seconds, and may be in a range of 1 second to 300 seconds, a range of 5 seconds to 250 seconds, or a range of 10 seconds to 200 seconds.

[0106] If a short circuit is detected as described herein, an alert may be output to the user, as shown for example in FIG. 7. The alert may include a visual alert, a vibratory alert, an audible alert, or a combination thereof.

[0107] When the alert is a visual alert, the visual alert may include a notification 700 shown on display 220 of reader device 200. Notification 700 may include a message, a graphic, or a combination of a message and a graphic. Notification 700 may advise the user of the potential short circuit condition (e.g., “short circuit detected”). Notification 700 may alternatively or additionally indicate a suggested corrective action (e.g., “please disconnect charging device”). Notification 700 may advise the user to disconnect the charging device for a predetermined period of time to allow the charging port to cool. Notification 700 may further advise the user to inspect or clean the charging port, to inspect or clean the charging device, and/or to use a different charging device. Exemplary notifications include “short circuit: disconnect charging device”, “check charging cable for damage”, “inspect charging port”, or “use different charging device”.

[0108] Display 220 of reader device 200 may display analyte data received from an in vivo analyte sensor 104. When a short circuit is detected, notification 700 may be displayed in addition to or in place of displayed analyte data. This allows the user to still view the analyte data while also being informed of the short circuit condition. For example, the notification may appear as a banner on an interface or window displaying the analyte data. In a further example, the notification 700 may replace or overlap all or a portion of the interface that displays analyte data. This may help to ensure the user is made aware of the dangerous short circuit condition and takes action in order to continue use of the reader device. The notification 700 may include a selectable button to be operated by the user to acknowledge the notification and/or to confirm the user has removed the charging device.

[0109] The visual alert may alternately or additionally include an icon shown on display 220 of reader device 200, such as an alarm icon, e.g., a bell, warning symbol, hazard symbol, or the like. The icon may be unique to the short circuit condition, or may be a general alarm icon that is used for notifying the user of other alert conditions of the analyte monitoring system. The visual alert may alternately or additionally include a change in color of all or a portion of the display. For example, a portion of the display may turn red or orange to indicate an error or alert condition. The visual alert may include a flashing of the display or an increase in brightness.

[0110] The alert may include an audible alert. The audible alert may be a tone, sound, or voice alert. Reader device 200 may include a speaker 290 for presenting the audible alert. The tone or sound may be selectable by the user, such as in a list of settings displayable on GUI of reader device 200. The tone or sound may be unique to the short circuit condition to distinguish the alert from other types of alerts, such as analyte alerts. When the audible alert is a voice, the voice may speak aloud a notification as described above to alert the user to the short circuit condition and/or to suggest a corrective action.

[OHl] After the initial detection of a short circuit, reader device 200 may continue to monitor for the presence of a short circuit based on a temperature of the charging port as described herein. The alert may continue to present until reader device 200 detects short circuit condition is no longer detected. Alternatively, alert may reoccur at a predetermined interval, e.g., 1 minute, 2 minutes, or 5 minutes, until short circuit condition is no longer detected. The notification may remain on the display until the short circuit condition is resolved. The notification may be closed but reappears if the short circuit condition is still present after a predetermined period of time, e.g., 1 minute, 2 minutes, or 5 minutes. The alert may escalate the longer the short circuit condition is detected to be present and may, for example, become louder, longer, brighter, or may change in color to indicate increasing severity of the condition.

[0112] Reader device 200 may optionally be configured to detect that a charging device is connected to charging port. Reader device 200 may include a sensor for detecting the presence of charging device. Reader device 200 may alternately detect presence of charging device based on detection of electricity communicated from charging device via charging port. In such embodiments, reader device 200 may stop outputting the alert when reader device 200 detects that charging device has been disconnected from charging port.

[0113] In some embodiments, when a short circuit is detected, reader device 200 may automatically disable charging. Reader device 200 may electrically isolate itself from the charging port. This may help to prevent or limit damage to reader device or user. In some embodiments, reader device 200 may be configured to automatically disconnect charging device from charging port when a short circuit is detected.

[0114] Some embodiments described herein relate to a reader device that is capable of detecting whether a charging device is suitable or compatible for use with the reader device. Reader device may be configured to detect a short circuit at the charging port, to determine whether the charging device is suitable for use with the reader device, or both. In this way, reader devices described herein provide improved safety by helping to detect or avoid short circuits and damage to the reader device or user.

[0115] A reader device of an analyte monitoring system may include a rechargeable power source, such as one or more rechargeable batteries. The reader device may include a charging port for connecting a charging device to the reader device to allow for recharging of the power source. As fast charging stations proliferate, many charging devices available in retail chains can be poorly designed and may have too high of power (e.g., too high of voltage) for the reader device and/or may not contain the appropriate safety protection mechanism in the event of a short circuit in the reader device or cabling. The existing safety protection mechanisms in some charging device can have high limit thresholds that may still pose safety issues in the case of short circuit.

[0116] If a short circuit occurs, the reader device or the charging device may rapidly generate heat and become extremely hot. The high temperatures can result in damage to the reader device, the charging device, the cabling, or even other properties. [0117] It is therefore crucial to charge a reader device with a suitable charging device. The charging device may have a power compatible with the reader device, and may have a power at or below the power requirement of the reader device. The charging device may additionally or alternatively have short circuit protection (e.g., overcurrent protection scheme) implemented. For example, the charging device can have a foldback circuit that responds to detected overcurrent by reducing output voltage and/or output current, thereby effectively limiting the power dissipation during a short circuit. It may be difficult for a user to determine whether a particular charging device is of the appropriate power requirements for the reader device or if it has short circuit protection. As a result, the user may be unaware that the charging device is not suitable, or is unsafe, for use with the reader device and creates a risk of overcurrent conditions. Thus, there is a need for a reader device that can determine if a suitable charging device is connected.

[0118] Described herein is a reader device for an analyte monitoring system that can detect whether a connected charging device is suitable for use. The reader device may be configured to determine if the charging device has appropriate power requirements or if the charging device has a suitable short circuit protection mechanism. The reader device may be configured to alert the user if not. The reader device may include charger testing circuitry to detect whether the connected charging device has appropriate power requirements or a suitable short circuit protection mechanism. Specifically, upon connection of a charging device to the reader device, the charger testing circuitry may cause a test load to be provided to the charging device. The test load may be configured to trigger a short circuit protection mechanism in the charging device, and if a suitable short circuit protection mechanism is present, the voltage output from the charging device in the charger test circuitry should be below a safety threshold. If the output voltage from the charging device is above the safety threshold, then the charging device is not suitable to be used with the reader device.

[0119] The reader device can further include a measuring device in communication with the charger testing circuitry to measure the voltage within the charger testing circuitry after the test load is supplied to the charging device. The measuring device may be implemented by a microcontroller of the reader device. Alternatively, the measuring device may include a comparator. The use of a comparator may help to save power relative to using a microcontroller. [0120] Upon detection of a charging device without a suitable circuit protection mechanism, the reader device may output a notification to alert the user that the charging device is not suitable for use. The notification may instruct the user to disconnect the charging device. Alternatively, the reader device may automatically prevent charging of the power source by the charging device. The reader device may prevent display of analyte data when the charging device is determined to be not suitable for use.

[0121] FIG. 8 is a block diagram depicting an example embodiment of a reader device 800. Reader device 800 may be substantially the same as reader device 200 in FIG. 3 except as noted herein. Reader device 800 includes charger testing circuitry 860 for determining if a connected charging device is suitable for use with reader device 800. Charger testing circuitry 860 may be in electrical communication with power source 826 and/or power management module 838. More details about charger testing circuitry 860 are set forth with respect to FIGS. 10 and 11 below. Charger testing circuitry 860 may be in communication with a processing device 870. As understood by one of skill in the art, these components are electrically and communicatively coupled in a manner to make a functional device.

[0122] Reader device 800 of FIG. 8 may additionally be configured to detect a short circuit and to alert the user to the short circuit condition as described herein. In such embodiments, reader device 800 includes a processing device in communication with one or more temperature sensors as described, for example, with respect to reader device 200 of FIG. 3. Alternatively, the reader device 800 of FIG. 8 may not include temperature sensors and a related processing device, such that reader device 800 does not detect a short circuit at the charging port.

[0123] Reader device 800 is configured to detect whether a connected charging device is suitable for use with reader device 800. A suitable charging device either has a power that is at or below the power requirement for the reader device, or has a protection mechanism against short circuit. In some embodiments, the power output from the charging device should be no more than a maximum power, such as 3 W. In some embodiments, the maximum power may be in a range of 2.5 W to 3 W for a suitable charging device.

[0124] Instructions for the charging device testing process may be stored in a memory of reader device, e.g., one or more of memory 823, 825, 839. When executed by a processing device, reader device 800 is configured to perform a series of steps to detect whether a connected charging device is suitable for use with the reader device and to alert the user if not. A processing device 870 in communication with charger testing circuitry 860, as shown for example in FIG. 8, may determine a voltage of charger testing circuitry 860 after a test load is provided to a connected charging device. Processing device 870 may determine voltage of charger testing circuitry 860 at different locations within charger testing circuitry 860, as further described herein. Processing device 870 may be a microcontroller, and may include an analog-to-digital converter. Processing device 870 may be a comparator, among other devices. The use of a separate, low power device, such as a comparator as processing device 870 may help to conserve power relative to using the processors 822, 824 of reader device 800, as processors 822, 824 of reader device 800 may have greater power consumption. Alternatively, instead of processing device 870, a one or both of processors 822, 824 may determine a voltage of charger testing circuitry 860, which may help to reduce the number of components and to simplify construction and manufacturing of reader device 800.

[0125] Reader device 800 is configured to communicate with a sensor control device 102. Sensor control device 102 may include an in vivo analyte sensor 104 for measuring one or more analytes as described herein with respect to reader device 200.

[0126] Reader device 800 may receive data from sensor control device 102, such as raw or processed analyte data and may determine and/or display analyte metrics based on the received analyte data. Reader device 800 may use artificial intelligence, such as machine learning, e.g., deep learning, as described herein with respect to reader device 200.

[0127] Display 820 of reader device 800 may display analyte data and other information, such as analyte data, a plot of analyte levels, current analyte level, analyte trend level, and may output alerts, as described herein with respect to reader device 200.

[0128] An exemplary reader device 800 is shown in FIG. 9. Reader device 800 may be substantially the same as reader device 200 of FIG. 4 except as noted herein. Reader device 800 may include a processing device and temperature sensors for detecting a short circuit as described with respect to reader device 200. Alternatively, reader device 800 may not include a processing device and temperature sensors such that reader device 800 does not detect short circuits.

[0129] Reader device 800 includes a housing 810 and a display 820 arranged on housing 810. Display 820 may include a liquid crystal display (LCD), a light emitting diode (LED) display, or an e-ink display, and may be a touchscreen display that is configured to receive user input, among other types of displays. Reader device 800 may further include one or more additional or alternate input components 830 for receiving user input, such as one or more of buttons, keys, a scroll wheel, or a touch pad, among others.

[0130] Reader device 800 may include a test strip port 840 for receiving an analyte test strip 845 carrying bodily fluid of the user, which can be analyzed to determine the user’s analyte level, such as the user’s blood sugar level or ketone level, among other analytes.

[0131] Reader device 800 includes a charging port 850 configured to be engaged with a connector 310 of a charging device 300. A power source of reader device 800 is configured to be charged by charging device 300 when charging device 300 is engaged with charging port 850. Charging device 300 may include, for example, a cable 320 having a first end with a connector 310 to be removably engaged with charging port 850, and a second end having a power adapter 330 for connection to an electrical outlet 400. Connector 310 may be received within charging port 850, and connector 310 and charging port 850 may be configured to mate, such as by a plug and socket or malefemale type connection. However, it is understood that other types of charging devices 300 may be used with reader device 800 consistent with the disclosure herein, such as a charging device that includes an external power source (e.g., an external battery pack or power bank), a cable connected to another electronic device, such as a laptop, such that reader device 800 is charged by the electronic device, among others. In some embodiments, charging port 850 is a USB port, such as USB-C or micro-USB port. However, charging port 850 may be any of various other types of ports known in the art for receiving power from a charging device.

[0132] Reader device 800 further includes charger testing circuitry 860 configured to detect whether a charging device 300 connected at charging port 850 is suitable to be used to charge reader device. Charger testing circuitry 860 can have a control input 862 and is in communication with a charger input 864. The charger input 864 can receive charging device 300 to charge a rechargeable power source of reader device 800. When charging device 300 is connected to reader device 800 and therefore charger input 864, control input 862 can cause a test load to be applied to charging device 300 through charger input 864. The test load is configured to trigger a short circuit protection mechanism of charging device 300, if one is present. An output voltage of charging device 300 is then measured by a measuring device 868 and compared to a threshold voltage level. The threshold voltage level may be around 0 V, or may be up to 4V, for example 0.5 V, IV, 2V, 3 V, or 4V. If the output voltage of charging device 300 after the application of the test load is below or equal to the threshold level, then it indicates charging device 300 either meets the power requirement to be used with reader device 800 or has a suitable short circuit protection mechanism that can effectively limit the power dissipation in the event of a short circuit. If, however, the output voltage of charging device 300 after the application of the test load is above the threshold level, then it indicates that charging device 300 is not suitable to be used with reader device 800.

[0133] In some embodiments, charger testing circuitry can include one or more fieldeffect transistors (FETs) to control the flow of current. The charger testing circuitry may include a pair of field-effect transistors. In some embodiments, charger testing circuitry can also include one or more resistors to provide different locations where a voltage can be measured. The charger testing circuitry can include a control input configured to provide a test load to the charger testing circuitry and to the charger input. The fieldeffect transistors may be biased in an off or inactive state until the test load is provided. A measuring device may measure a voltage level in the charger testing circuitry after application of the test load.

[0134] One embodiment of charger testing circuitry 860a is shown in FIG. 10. Charger testing circuitry 860a may include a control input 862 to provide a test load. Charger testing circuitry 860a may include a charger input 864 configured to be electrically connected to a charging device 300 and to communicate the test load to charging device 300. Charger testing circuitry 860a may include one or more field-effect transistors. For example, two field-effect transistors, a first field-effect transistor Ml and a second fieldeffect transistor M2, are shown in FIG. 10. A first resistor R1 can be in direct electrical communication with charger input 864 and first field-effect transistor Ml to maintain first field-effect transistor Ml closed/off when a charge is provided from charger input 864. Additional resistors, such as a second resistor R2 and a third resistor R3 as shown in FIG. 10, can scale the voltage from charger input 864. Charger input 864 can be in electrical communication with charging port 850 to receive a charge from charging device 300. When charging port 850 is a USB port, charger input 864 is a USB input providing a USB bus voltage, which may be for example, approximately nominally 5 V. Control input 862 can provide a test load to charger testing circuitry 860a, and through charger testing circuitry 860a. In some embodiments, control input 862 may generate the test load.

[0135] First field-effect transistor Ml may have its source terminal S in direct electrical communication with charger input 864 and gate terminal G in direct electrical communication with first resistor Rl. The resistance of first resistor R1 may be large enough, such that when a charge is present from charger input 864, first resistor Rl holds the gate-source voltage of first field-effect transistor Ml at 0 V, so that first field-effect transistor Ml is off, and there is no current passing through first field-effect transistor Ml. For example, first resistor Rl can have a resistance in a range of 5 kQ to 15 kQ, 7 kQ to 13 k , or about 10 kQ.

[0136] Second field-effect transistor M2 has its drain terminal D in direct electrical communication with first resistor Rl, its source terminal S grounded, and its gate terminal G in electrical communication with control input 862. When a charge is present from charger input 864 and no charge is present from control input 862, second field-effect transistor M2 is on and allows current passing through to ground.

[0137] Upon detection of charging device 300 connected with charging port 850, reader device causes the control input 862 to provide a test load, which enables, or turns on, first field-effect transistor Ml and second field-effect transistor M2 because a voltage is supplied to both gate terminals. The test load is then supplied to charging device 300 via charger input 864. The test load can be high enough to trigger a protection mechanism in charging device 300, if one is present, and as a result, output voltage of charging device 300, and therefore charger input 864, will drop below a threshold level. For example, the test load is large enough to provide a current to charging device 300 in a range of 650 mA to 1000 mA, such as 700 mA to 900 mA, or approximately 833 mA, sufficient to trigger the protection mechanism of the charging device, if present. The protection mechanism may be a foldback circuit, which in response to detected overcurrent can reduce output voltage and output current. Alternatively, if charging device 300 does not have a protection mechanism against short circuit but has appropriate power requirements for the reader device (e.g., power below a maximum power of the reader device), when the test load is provided, the output voltage of charging device 300 will be below a threshold voltage level. [0138] If charging device 300 implements a suitable protection mechanism against short circuit, the protection mechanism will be triggered upon the current supplied by the test load, and the output voltage of charging device 300 through charger input 864 will be reduced to below a threshold level. For example, the threshold voltage from charger input 864 may be about 0 V, so that a voltage measured elsewhere in charger testing circuitry 860a is also 0 V. Alternatively, the threshold voltage is not 0 V, but it may still be low enough to effectively limit the power dissipation during a short circuit. For example, if the voltage is 4 V or higher, then the charging device does not have a foldback circuit or other protection circuitry. The voltage from the test load should drop if the charging device is suitable for use, and may drop to 0 V when the charging device includes a foldback circuit.

[0139] To measure the output voltage from charger input 864, a measuring device 868 can measure the voltage at different locations of charger testing circuitry 860. For example, measuring device 868 can be positioned at location 865 between first fieldeffect transistor Ml and second resistor R2, or location 866 between second resistor R2 and third resistor R3. Measuring device 868 can measure the voltage at the location relative to the ground. Measuring device 868 can be processing device 870 or part of processing device 870. The voltage measured at different locations will be scaled from the voltage from charger input 864 based on the resistance of each electric component. For example, the voltage measured at location 865 is larger than the voltage measured at location 866, and a ratio of voltage at location 865 to the voltage at location 866 can be represented by (R2+R3)/R3. The location to measure the voltage can be determined based on the capacity of the measuring device (e.g., processing device 870). If the measuring device has a lower measuring capacity, the voltage can be measured at location 866 instead of location 865, and the resistance of second resistor R2 can be increased or the resistance of third resistor R3 can be decreased to further scaled down the voltage measured at location 866.

[0140] The number of resistors can vary in different embodiments. The embodiment shown in FIG. 10 includes two resistors, R2 and R3, between the drain terminal D of first field-effect transistor Ml and the ground. The voltage may be measured between resistors R2 and R3, which is scaled down from the voltage between Ml and R2. This may be beneficial where the measuring device cannot receive a high voltage, and reduces the voltage to a level suitable for the measuring device, such as a processor with an analog to digital converter.

[0141] An alternative embodiment of charger testing circuitry 860b is shown in FIG. 11. Charger testing circuitry 860b is substantially the same as charger testing circuitry 860a of FIG. 10, and differs in including a single resistor R4 in place of resistors R2, R3 in FIG. 10. If there is not a need to reduce the voltage to accommodate the voltage capacity of measuring device 868, a single resistor R4 may be used in place of resistors R2 and R3. The voltage may be measured by measuring device 868 at location 865 between first field-effect transistor Ml and resistor R4.

[0142] In yet another embodiment, three or more resistors can be placed between the drain terminal D of first field-effect transistor Ml and the ground. The voltage measured across different resistors will be scaled relative to the resistance of each resistors, and can be altered to suit a specific design condition, for example, when the measuring capacity of the measuring device is lower than the expected voltage from charger input 864.

[0143] If the measured voltage in charger testing circuitry 860 is above the predetermined threshold voltage output after the supply of test load, then it indicates that charging device 300 is not suitable for use. The charging device may not include suitable protection mechanism against short circuit, such that it is not safe to use with reader device 200. Alternatively, the charging device may have a power that is too high for the reader device. For example, if the threshold voltage is approximately 0 V, then a measured voltage above 0 V indicates that charging device 300 is not suitable for use. The determination of whether measured voltage is above the threshold voltage can be performed by processing device 870.

[0144] Upon determination that charging device 300 is not suitable for use, reader device 800 can provide a notification to the user that that charging device 300 is not suitable for use. Such notification can be one or more of a visual notification provided via display 820 reader device 800 or an audible notification provided via a speaker 890 of reader device 800. In additional to providing a notification, reader device 800 can also automatically prevent charging by charging device 300, if the user has not responded to the notification after a predetermined time period, such that power source is not charged by the charging device 300. Alternatively, reader device 800 can prevent charging from charging device 300 immediately upon determination that charging device 300 is not suitable for use. [0145] A method 1200 of detect whether a connected charging device 300 has a suitable short circuit protection mechanism according to an embodiment is shown in FIG. 12. In an optional first step, step 1210, reader device 800 can detect whether a charging device 300 is connected to charging port 850. Reader device 800 may include a sensor for detecting the presence of charging device, and processing device 870 or other processors of reader device 800 can receive the feedback from the sensor. Reader device 800 may alternately detect presence of charging device based on detection of electricity communicated from charging device via charging port.

[0146] At step 1220, a test load can be provided through charger testing circuitry 860 via control input 862. The test load can be supplied by processing device 870 or other processors of reader device 800. The test load can be applied for a predetermined time period, for example up to 5 seconds. The test load will then be supplied to charging device 300, and it is large enough to trigger a protection mechanism, if one is present. Thereafter at step 1230, a voltage in charger testing circuitry 860 is measured. The voltage can be measured at different locations in charger testing circuitry 860, such as location 865 or location 866 shown in FIGS. 10 and 11. The voltage can be measured by a measuring device 868, and in some embodiments, measuring device 868 can be processing device 870 or other processors of reader device 800.

[0147] At step 1240, the measured voltage from step 1230 is compared to the threshold voltage level, which is the expected voltage output of charging device 300 after the test load is supplied. If the measured voltage is less than or equal to the threshold voltage level, then it indicates charging device 300 is safe to use, and reader device 800 is charged by the charging device at step 1250 and continues on the normal operation of reader device 800 to receive and display analyte data at step 1260. If, however, at step 1240, the measured voltage (after scaling) is larger than the threshold voltage level, then charging device 300 is not safe to use, and reader device 800 may provide a notification to the user at step 1270, and optionally the reader device 800 can reject charging by charging device 300 at step 1280.

[0148] If it is determined that charging device 300 does not have suitable protection mechanism, reader device 800 may output a notification to the user, as shown for example in FIG. 13. The notification may include a visual notification, a vibratory notification, an audible notification, or a combination thereof. [0149] When the notification is a visual notification, the visual notification may include a notification 710 shown on display 820 of reader device 800. Notification 710 may include a message, a graphic, or a combination of a message and a graphic. Notification 710 may advise the user that the connected charging device is unsafe to use because it does not have suitable protection mechanism against short circuit (e.g., “charging device unsafe to use”). Notification 710 may alternatively or additionally indicate a suggested corrective action (e.g., “please disconnect charging device”).

[0150] The visual notification may alternately or additionally include an icon shown on display 820 of reader device 800, such as an alarm icon, e.g., a bell, warning symbol, hazard symbol, or the like. The icon may be unique to the short circuit condition, or may be a general alarm icon that is used for notifying the user of other alert conditions of the analyte monitoring system. The visual notification may alternately or additionally include a change in color of all or a portion of the display. For example, a portion of the display may turn red or orange to indicate an error or alert condition. The visual notification may include a flashing of the display or an increase in brightness.

[0151] The notification may include an audible notification. The audible notification may be a tone, sound, or voice notification. Reader device 800 may include a speaker 890 for presenting the audible notification. The tone or sound may be selectable by the user, such as in a list of settings displayable on GUI of reader device 800. The tone or sound may be unique to charging device condition to distinguish from other types of notifications, such as glucose alerts. When the audible notification is a voice, the voice may speak aloud a notification as described above to notification the user to the charging device condition and/or to suggest a corrective action.

[0152] After providing the notification, reader device 800 may continue to monitor for the condition of charging device 300. The notification may continue to present until charging device 300 is disconnected. Alternatively, notification may reoccur at a predetermined interval, e.g., 1 minute, 2 minutes, or 5 minutes, until charging device 300 is disconnected. The notification may remain on the display until charging device 300 is disconnected. The notification may be closed, if the user decides to proceed with charging by charging device 300 at their own risk. The notification may be closed but reappears after a predetermined period of time, e.g., 1 minute, 2 minutes, or 5 minutes until charging device 300 is disconnected. [0153] In some embodiments, reader device 800 may automatically disable charging if a suitable protection mechanism is not detected in charging device 300 or if the power supplied by charging device is too high. Reader device 800 may electrically isolate itself from charging port 850.

[0154] Exemplary embodiments are set out in the following numbered clauses.

[0155] Clause 1 : A reader device for displaying analyte data, the reader device comprising: a housing; a charging port arranged on the housing, wherein the charging port is configured to engage with a connector of a charging device; a power source arranged within the reader device configured to be charged by the charging device when the charging device is engaged with the charging port; communication circuitry for receiving analyte data from a sensor control device having an in vivo analyte sensor; a display arranged on the housing for displaying at least a portion of the analyte data received from the sensor control device; a first temperature sensor configured to measure a first temperature of the charging port; a second temperature sensor configured to measure a second temperature, wherein the second temperature is an internal temperature within the housing; and a processing device in communication with the first and second temperature sensors and configured to detect a short circuit, wherein the processing device is configured to: receive the first temperature measured by the first temperature sensor, receive the second temperature measured by the second temperature sensor, calculate a difference between the first temperature and the second temperature, compare the difference to a temperature difference threshold, and output an alert when the difference exceeds the temperature difference threshold. [0156] Clause 2: The reader device of clause 1, wherein the alert comprises a notification output on the display of the reader device.

[0157] Clause 3: The reader device of clause 1 or clause 2, wherein the alert comprises one or more of an audible alert or a vibratory alert.

[0158] Clause 4: The reader device of any of clauses 1-3, wherein the processing device comprises a comparator.

[0159] Clause 5: The reader device of any of clauses 1-4, wherein the processing device is further configured to receive the first and second temperatures at a predetermined sampling interval.

[0160] Clause 6: The reader device of clause 5, wherein the predetermined sampling interval is between 1 second and 300 seconds, 5 seconds and 250 seconds, or 10 seconds and 200 seconds.

[0161] Clause 7: The reader device of clause 5 or clause 6, wherein the predetermined sampling interval is based on a thermal time constant of the first temperature sensor.

[0162] Clause 8: The reader device of any of clauses 1-7, wherein at least one of the first temperature sensor and second temperature sensor is one of a thermistor, a thermocouple, a resistance temperature detector, a negative temperature coefficient element, a positive temperature coefficient element, or an active silicon temperature sensor.

[0163] Clause 9: The reader device of any of clauses 1-8, wherein the first temperature sensor directly contacts the charging port.

[0164] Clause 10: The reader device of any of clauses 1-9, wherein the temperature difference threshold is 10°C, 15°C, or 20°C.

[0165] Clause 11 : The reader device of any of clauses 1-10, wherein the temperature difference threshold is dynamically determined by the reader device.

[0166] Clause 12: The reader device of any of clauses 1-11, further comprising a processor, wherein the processor is coupled to the communication circuitry and to the display.

[0167] Clause 13: The reader device of any of clauses 1-12, further comprising a processing core including a communications processor coupled with a first memory and an applications processor coupled with a second memory.

[0168] Clause 14: The reader device of any of clauses 1-13, further comprising one or more input devices for receiving a user input. [0169] Clause 15: The reader device of any of clauses 1-14, wherein the communication circuitry comprises a transceiver.

[0170] Clause 16: The reader device of any of clauses 1-15, wherein the communication circuitry receives analyte data from the sensor control device by Bluetooth communication.

[0171] Clause 17: The reader device of any of clauses 1-16, wherein the display displays a graphical user interface comprising a plot of analyte levels over time based on the received analyte data.

[0172] Clause 18: The reader device of any of clauses 1-17, further comprising a test strip port for receiving an analyte test strip.

[0173] Clause 19: The reader device of any of clauses 1-18, wherein the processing device is configured to: determine a first rate of change of the first temperature, determine a second rate of change of the second temperature, calculate a difference between the first rate of change and the second rate of change, compare the difference between the first rate of change and the second rate of change to a rate of change difference threshold, and output the alert when the difference between the first rate of change and the second rate of change exceeds the rate of change difference threshold.

[0174] Clause 20: A reader device for displaying analyte data, the reader device comprising: a housing; a charging port arranged on the housing, wherein the charging port is configured to engage with a connector of a charging device; a power source arranged within the reader device configured to be charged by the charging device when the charging device is engaged with the charging port; communication circuitry for receiving analyte data from a sensor control device comprising an in vivo analyte sensor; a display arranged on the housing for displaying at least a portion of the analyte data received from the sensor control device; a first temperature sensor configured to measure a first temperature of the charging port; a second temperature sensor configured to measure a second temperature, wherein the second temperature is an internal temperature within the housing; and a processing device in communication with the first and second temperature sensors, wherein the processing device is configured to: determine a first rate of change of the first temperature, determine a second rate of change of the second temperature, calculate a difference between the first rate of change and the second rate of change, compare the difference between the first rate of change and the second rate of change to a rate of change difference threshold, and output the alert when the difference between the first rate of change and the second rate of change exceeds the rate of change difference threshold.

[0175] Clause 21 : The reader device of clause 20, wherein the alert comprises a notification output on the display of the reader device.

[0176] Clause 22: The reader device of clause 20 or clause 21, wherein the alert comprises one or more of an audible alert or a vibratory alert.

[0177] Clause 23 : The reader device of any of clauses 20-22, wherein the processing device comprises a comparator.

[0178] Clause 24: The reader device of any of clauses 20-23, wherein the processing device is further configured to determine the first and second rates of change at a predetermined sampling interval.

[0179] Clause 25: The reader device of any of clauses 20-24, wherein the predetermined sampling interval is between 1 second and 300 seconds, 5 seconds and 250 seconds, or 10 seconds and 200 seconds.

[0180] Clause 26: The reader device of any of clauses 20-25, wherein the predetermined sampling interval is based on a thermal time constant of the first temperature sensor.

[0181] Clause 27: The reader device of any of clauses 20-26, wherein the rate of change difference threshold may be predetermined amount in a range of 0.033°C/second to l°C/second. [0182] Clause 28: The reader device of any of clauses 20-26, wherein the temperature difference threshold is dynamically determined by the reader device.

[0183] Clause 29: The reader device of any of clauses 20-28, further comprising a processor, wherein the processor is coupled to the communication circuitry and to the display.

[0184] Clause 30: A method for detecting a short circuit at a charging port of a reader device configured to display analyte data, the method comprising: receiving, by communication circuitry of the reader device, the analyte data from a sensor control device comprising an in vivo analyte sensor; displaying, by a display of the reader device, at least a portion of the analyte data received from the sensor control device; charging a power source of the reader device when a connector of a charging device is engaged with a charging port of the reader device; measuring, by a first temperature sensor of the reader device, a first temperature of the charging port of the reader device when the charging device is engaged with the charging port; measuring, by a second temperature sensor of the reader device, a second temperature, wherein the second temperature is an internal temperature within the housing; calculating, by a processing device of the reader device, a difference between the first temperature and the second temperature; comparing, by the processing device, the difference to a temperature difference threshold; and outputting, by the reader device, an alert when the difference exceeds the temperature difference threshold.

[0185] Clause 31 : The method of clause 30, wherein the first and second temperatures are measured at a predetermined sampling interval.

[0186] Clause 32: The method of clause 30 or clause 31, wherein the outputting the alert comprises outputting a notification on the display of the reader device.

[0187] Clause 33: A method for detecting a short circuit at a charging port of a reader device configured to display analyte data, the method comprising: receiving, by communication circuitry of the reader device, the analyte data from a sensor control device comprising an in vivo analyte sensor; displaying, by a display of the reader device, at least a portion of the analyte data received from the sensor control device; charging a power source of the reader device when a connector of a charging device is engaged with a charging port of the reader device; measuring, by a first temperature sensor of the reader device, a first temperature of the charging port of the reader device; measuring, by a second temperature sensor of the reader device, a second temperature, wherein the second temperature is an internal temperature within the housing; determining, by a processing device, a first rate of change of the first temperature; determining, by the processing device, a second rate of change of the second temperature; calculating, by the processing device, a difference between the first rate of change and the second rate of change; comparing, by the processing device, the difference to a rate of change difference threshold; and outputting, by the reader device, an alert when the difference between the first rate of change and the second rate of change exceeds the rate of change difference threshold.

[0188] Clause 34: The method of clause 33, wherein the first and second temperatures are measured at a predetermined sampling interval.

[0189] Clause 35: The method of clause 33 or clause 34, wherein the outputting the alert comprises outputting a notification on the display of the reader device.

[0190] Clause 36: A reader device for displaying analyte data collected by an in vivo analyte sensor, the reader device comprising: a display for displaying the analyte data; a rechargeable power source; charger testing circuitry configured to determine if a charging device configured to charge the rechargeable power source is suitable for use with the reader device, the charger testing circuitry comprising: a charger input configured to receive the charging device; and a control input configured to cause a test load to be applied to the charging device connected to the charger input; and a measuring device in communication with the charger testing circuitry and configured to measure a voltage in the charger testing circuitry when the test load is supplied to the charging device, wherein when the measured voltage is above a threshold voltage level, the reader device is configured to provide a notification to a user indicating that the charging device is not suitable for use.

[0191] Clause 37: The reader device of clause 36, wherein when the measured voltage is below the threshold voltage level, the reader device is configured to display the analyte data.

[0192] Clause 38: The reader device of any of clauses 36-37, wherein the charging device is a USB charger and the charger input comprises a USB input.

[0193] Clause 39: The reader device of any of clauses 36-38, wherein the charger input is configured to receive a 5 V input.

[0194] Clause 40: The reader device of any of clauses 36-39, wherein the test load is configured to provide a current to the charging device in a range of 650 mA to 1000 mA.

[0195] Clause 41 : The reader device of any of clauses 36-40, wherein the threshold voltage level is around 0 V.

[0196] Clause 42: The reader device of any of clauses 36-41, wherein the control input is configured to cause the test load to be applied for a predetermined time period.

[0197] Clause 43: The reader device of any of clauses 36-42, wherein the control input causes the test load to be applied by generating a resistance load in the charger testing circuitry.

[0198] Clause 44: The reader device of clause 43, wherein the measuring device is configured to measure the voltage across the resistance load.

[0199] Clause 45: The reader device of any of clauses 36-44, wherein when the measured voltage is above a threshold voltage level, the reader device is configured to prevent the charging device from charging the rechargeable power source.

[0200] Clause 46: The reader device of any of clauses 36-45, wherein the charger testing circuitry further comprises one or more field effect transistors. [0201] Clause 47: The reader device of clause 46, wherein the charger testing circuitry comprises: a first field effect transistor; and a second field effect transistor, wherein the first field effect transistor and the second field effect transistor are inactive before the test load is applied and are activated via the control input.

[0202] Clause 48: The reader device of clause 47, wherein the first field effect transistor is in electrical communication with the charger input and with a first resistor, wherein the first resistor is positioned between the first field effect transistor and the second field effect transistor.

[0203] Clause 49: The reader device of clause 47 or 48, wherein the measuring device is configured to measure the voltage in the charger testing circuitry between the first field effect transistor and the first resistor.

[0204] Clause 50: The reader device of clause 47 or 48, further comprising a second resistor positioned between the first resistor and the second field effect transistor, wherein the measuring device is configured to measure the voltage in the charger testing circuitry between the first resistor and the second resistor.

[0205] Clause 51 : The reader device of any of clauses 36-50, wherein the notification comprises one or more of a visual notification provided via the display of the reader device or an audible notification provided by the reader device.

[0206] Clause 52: The reader device of any of clauses 36-51, wherein measuring device is a microcontroller.

[0207] Clause 53: The reader device of clause 52, wherein the microcontroller comprises an analog to digital converter.

[0208] Clause 54: The reader device of any of clauses 36-53, wherein the measuring device is a comparator.

[0209] Clause 55: An analyte monitoring system, comprising: the reader device of any of clauses 36-54; and an in vivo analyte monitoring device, comprising: an analyte sensor comprising a first portion configured to be arranged above a skin surface and a second portion configured to be arranged below the skin surface and in contact with a bodily fluid of the user to sense analyte levels; and sensor electronics coupled to the first portion of the analyte sensor, the sensor electronics comprising a processor and wireless communication circuitry for wirelessly communicating analyte data to the reader device.

[0210] Clause 56: A method of determining if a charging device is suitable for use with a reader device of an analyte monitoring system, the method comprising: receiving a charging input from the charging device connected to the reader device, wherein the reader device comprises a rechargeable power source configured to be charged by the charging device; applying a test load, using a control input of charger testing circuitry of the reader device, to the charging device; measuring a voltage in the charger testing circuitry by a measuring device of the reader device when the test load is provided to the charging device; and outputting a notification when the measured voltage is above a threshold voltage level indicating that the charging device is not suitable for use.

[0211] Clause 57: The method of clause 56, wherein if the measured voltage is at or below the threshold voltage level, the method further comprises: displaying analyte data on the display of the reader device, wherein the analyte data is collected by an in vivo analyte sensor.

[0212] Clause 58: The method of any of clauses 56-57, wherein if the measured voltage is at or below the threshold voltage level, the method further comprises: charging the rechargeable power source of the reader device.

[0213] Clause 59: The method of any of clauses 56-58, wherein the threshold voltage level is around 0 V.

[0214] Clause 60: The method of any of clauses 56-59, wherein providing the test load comprises providing a current to the charging device in a range of 650 mA to 1000 mA.

[0215] Clause 61 : The method of any of clauses 56-60, wherein outputting the notification comprises displaying a visual notification on the display of the reader device.

[0216] Clause 62: The method of any of clauses 56-61, wherein the voltage is measured by a microcontroller of the reader device. [0217] Clause 63: The method of any of clauses 56-62, wherein the test load is applied for a predetermined time period.

[0218] Clause 64: The method of any of clauses 56-63, wherein applying the test load comprises generating a resistance load in the charger testing circuitry.

[0219] Clause 65: The method of clause 64, wherein measuring a voltage in the charger testing circuitry comprises measuring the voltage across the resistance load.

[0220] Clause 66: The method of any of clauses 56-65, comprising preventing the charging device from charging the rechargeable power source when the measured voltage is above a threshold voltage level.

[0221] Clause 67: The method of any of claims 56-66, wherein the charger testing circuitry comprises a first field effect transistor and a second field effect transistor.

[0222] Clause 68: The method of clause 67, wherein the first field effect transistor is in electrical communication with the charger input and a first resistor positioned between the first field effect transistor and the second field effect transistor, and wherein the voltage is measured between the first field effect transistor and the first resistor.

[0223] Clause 69: A reader device for displaying analyte data, the reader device comprising: a housing; a charging port arranged on the housing, wherein the charging port is configured to engage with a charging device; a power source arranged within the reader device configured to be charged by the charging device when the charging device is engaged with the charging port; communication circuitry for receiving analyte data from a sensor control device comprising an in vivo analyte sensor; a display arranged on the housing for displaying at least a portion of the analyte data received from the sensor control device; charger testing circuitry configured to determine if the charging device is suitable for use with the reader device; and a short circuit detection assembly configured to detect a short circuit when the charging device is connected to the charging port, wherein the display is configured to provide a notification when a short circuit is detected or when the charging device is determined to be unsuitable for use with the reader device.

[0224] Clause 70: The reader device of clause 69, wherein the short circuit detection assembly comprises a first temperature sensor configured to measure a first temperature of the charging port, and wherein the short circuit is detected based on the first temperature.

[0225] Clause 71 : The reader device of clause 70, wherein the short circuit detection assembly further comprises a second temperature sensor configured to measure a second temperature, wherein the second temperature is an internal temperature within the housing.

[0226] Clause 72: The reader device of clause 71, wherein the short circuit detection assembly comprises a processing device configured to detect a short circuit when a difference between the first temperature and the second temperature exceeds a temperature difference threshold.

[0227] Clause 73: The reader device of clause 71, wherein the short circuit detection assembly comprises a processing device configured to detect a short circuit when a difference between a rate of change of the first temperature and a rate of change of the second temperature exceeds a rate of change difference threshold.

[0228] Clause 74: The reader device of any one of clause 69-73, wherein the charger testing circuitry comprises a control input configured to cause a test load to be applied to the charging device.

[0229] Clause 75: The reader device of clause 74, wherein the reader device comprises a measuring device in communication with the charger testing circuitry, wherein the measuring device is configured to measure a voltage in the charger testing circuitry when the test load is supplied to the charging device.

[0230] Clause 76: The reader device of clause 75, wherein the reader device determines that the charging device is suitable for use with the reader device when the voltage measured is below or equal to a threshold voltage.

[0231] Clause 77: The reader device of any one of clauses 69-76, wherein the charger testing circuitry comprises one or more field effect transistors. [0232] Clause 78: The reader device of any one of clauses 69-77, wherein the reader device is configured to display the analyte data received from the sensor control device when the charger testing circuitry determines that the charging device is suitable for use with the reader device.

[0233] Clause 79: A method for detecting a short circuit at a charging port of a reader device configured to display analyte data, the method comprising: receiving, by communication circuitry of the reader device, the analyte data from a sensor control device comprising an in vivo analyte sensor; displaying, by a display of the reader device, at least a portion of the analyte data received from the sensor control device; determining, by charger testing circuitry, if a charging device connected to a charging port of the reader device is suitable for use with the reader device; and monitoring, by a short circuit detection assembly, for a short circuit at the charging port of the reader device; and outputting a notification on the display of the reader device when the charging device is not suitable for use with the reader device or when a short circuit is detected.

[0234] Clause 80: The method of claim 79, wherein monitoring for a short circuit comprises measuring a temperature of the charging port by a first temperature sensor of the short circuit detection assembly.

[0235] Clause 81 : The method of claim 80, wherein monitoring for a short circuit comprises measuring a second temperature that is a temperature within the reader device by a second temperature of the short circuit detection assembly.

[0236] Clause 82: The method of claim 81, wherein monitoring for a short circuit comprises determining, by a processing device of the short circuit detection assembly, a difference between the first temperature and the second temperature, wherein a short circuit is detected when the difference exceeds a temperature difference threshold.

[0237] Clause 83: The method of claim 81, wherein monitoring for a short circuit comprises determining, by a processing device of the short circuit detection assembly, a difference between a rate of change of the first temperature and a rate of change of the second temperature, wherein a short circuit is detected when the difference exceeds a rate of change difference threshold. [0238] Clause 84: The method of clause 79, wherein determining if a charging device connected to a charging port of the reader device is suitable for use with the reader device comprises applying a test load by a control input of charger testing circuitry to the charging device.

[0239] Clause 85: The method of clause 84, further comprising measuring a voltage in the charger testing circuitry when the test load is applied to the charger testing circuitry.

[0240] Clause 86: The method of clause 85, further comprising determining that the charging device is suitable for use with the reader device when the voltage measured is below or equal to a voltage threshold.

[0241] Clause 87: The method of any of clauses 79-86, wherein the charger testing circuitry comprises one or more field effect transistors.

[0242] Clause 88: The method of any of clauses 79-87, further comprising displaying the analyte data received from the sensor control device when the charger testing circuitry determines that the charging device is suitable for use with the reader device.

[0243] It is to be appreciated that the Detailed Description section, and not the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present invention(s) as contemplated by the inventors, and thus, are not intended to limit the present invention(s) and the appended claims in any way.

[0244] While the disclosed subject matter is described herein in terms of certain preferred embodiments for purpose of illustration and not limitation, those skilled in the art will recognize that various modifications and improvements can be made to the disclosed subject matter without departing from the scope thereof. Moreover, although individual features of one embodiment of the disclosed subject matter can be discussed herein or shown in the drawings of one embodiment and not in other embodiments, it should be readily apparent that individual features of one embodiment can be combined with one or more features of another embodiment or features from a plurality of embodiments.

[0245] The foregoing description of the specific embodiments will so fully reveal the general nature of the invention(s) that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, and without departing from the general concept of the present invention(s). Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance herein.

Claims

WHAT IS CLAIMED IS:

1. A reader device for displaying analyte data, the reader device comprising: a housing; a charging port arranged on the housing, wherein the charging port is configured to engage with a connector of a charging device; a power source arranged within the reader device configured to be charged by the charging device when the charging device is engaged with the charging port; communication circuitry for receiving analyte data from a sensor control device comprising an in vivo analyte sensor; a display arranged on the housing for displaying at least a portion of the analyte data received from the sensor control device; a first temperature sensor configured to measure a first temperature of the charging port; a second temperature sensor configured to measure a second temperature, wherein the second temperature is an internal temperature within the housing; and a processing device in communication with the first and second temperature sensors and configured to detect a short circuit, wherein the processing device is configured to: receive the first temperature measured by the first temperature sensor, receive the second temperature measured by the second temperature sensor, calculate a difference between the first temperature and the second temperature, compare the difference to a temperature difference threshold, and output an alert when the difference exceeds the temperature difference threshold.

2. The reader device of claim 1, wherein the alert comprises a notification output on the display of the reader device.

3. The reader device of claim 1, wherein the alert comprises one or more of an audible alert or a vibratory alert.

4. The reader device of claim 1, wherein the processing device comprises a comparator.

5. The reader device of claim 1, wherein the processing device is further configured to receive the first and second temperatures at a predetermined sampling interval.

6. The reader device of claim 5, wherein the predetermined sampling interval is between 1 second and 300 seconds.

7. The reader device of claim 5, wherein the predetermined sampling interval is based on a thermal time constant of the first temperature sensor.

8. The reader device of claim 1, wherein at least one of the first temperature sensor and second temperature sensor is one of a thermistor, a thermocouple, a resistance temperature detector, a negative temperature coefficient element, a positive temperature coefficient element, or an active silicon temperature sensor.

9. The reader device of claim 1, wherein the temperature difference threshold is 10°C.

10. The reader device of claim 1, wherein the temperature difference threshold is dynamically determined by the reader device.

11. The reader device of claim 1, further comprising a processor, wherein the processor is coupled to the communication circuitry and to the display.

12. A reader device for displaying analyte data, the reader device comprising: a housing; a charging port arranged on the housing, wherein the charging port is configured to engage with a connector of a charging device; a power source arranged within the reader device configured to be charged by the charging device when the charging device is engaged with the charging port; communication circuitry for receiving analyte data from a sensor control device comprising an in vivo analyte sensor; a display arranged on the housing for displaying at least a portion of the analyte data received from the sensor control device; a first temperature sensor configured to measure a first temperature of the charging port; a second temperature sensor configured to measure a second temperature, wherein the second temperature is an internal temperature within the housing; and a processing device in communication with the first and second temperature sensors, wherein the processing device is configured to: determine a first rate of change of the first temperature, determine a second rate of change of the second temperature, calculate a difference between the first rate of change and the second rate of change, compare the difference between the first rate of change and the second rate of change to a rate of change difference threshold, and output the alert when the difference between the first rate of change and the second rate of change exceeds the rate of change difference threshold.

13. The reader device of claim 12, wherein the alert comprises a notification output on the display of the reader device.

14. The reader device of claim 12, wherein the processing device comprises a comparator.

15. The reader device of claim 12, wherein the processing device is further configured to determine the first and second rates of change at a predetermined sampling interval.

16. The reader device of claim 15, wherein the predetermined sampling interval is based on a thermal time constant of the first temperature sensor.

17. A method for detecting a short circuit at a charging port of a reader device configured to display analyte data, the method comprising: receiving, by communication circuitry of the reader device, the analyte data from a sensor control device comprising an in vivo analyte sensor; displaying, by a display of the reader device, at least a portion of the analyte data received from the sensor control device; charging a power source of the reader device when a connector of a charging device is engaged with a charging port of the reader device; measuring, by a first temperature sensor of the reader device, a first temperature of the charging port of the reader device when the charging device is engaged with the charging port; measuring, by a second temperature sensor of the reader device, a second temperature, wherein the second temperature is an internal temperature within the housing; calculating, by a processing device of the reader device, a difference between the first temperature and the second temperature; comparing, by the processing device, the difference to a temperature difference threshold; and outputting, by the reader device, an alert when the difference exceeds the temperature difference threshold.

18. The method of claim 17, wherein the first and second temperatures are measured at a predetermined sampling interval.

19. The method of claim 17, wherein the outputting the alert comprises outputting a notification on the display of the reader device.

20. A method for detecting a short circuit at a charging port of a reader device configured to display analyte data, the method comprising: receiving, by communication circuitry of the reader device, the analyte data from a sensor control device comprising an in vivo analyte sensor; displaying, by a display of the reader device, at least a portion of the analyte data received from the sensor control device; charging a power source of the reader device when a connector of a charging device is engaged with a charging port of the reader device; measuring, by a first temperature sensor of the reader device, a first temperature of the charging port of the reader device; measuring, by a second temperature sensor of the reader device, a second temperature, wherein the second temperature is an internal temperature within the housing; determining, by a processing device, a first rate of change of the first temperature; determining, by the processing device, a second rate of change of the second temperature; calculating, by the processing device, a difference between the first rate of change and the second rate of change; comparing, by the processing device, the difference to a rate of change difference threshold; and outputting, by the reader device, an alert when the difference between the first rate of change and the second rate of change exceeds the rate of change difference threshold.

21. The method of claim 20, wherein the first and second temperatures are measured at a predetermined sampling interval.

22. The method of claim 20, wherein the outputting the alert comprises outputting a notification on the display of the reader device.

23. A reader device for displaying analyte data collected by an in vivo analyte sensor, the reader device comprising: a display for displaying the analyte data; a rechargeable power source; charger testing circuitry configured to determine if a charging device configured to charge the rechargeable power source is suitable for use with the reader device, the charger testing circuitry comprising: a charger input configured to receive the charging device; and a control input configured to cause a test load to be applied to the charging device connected to the charger input; and a measuring device in communication with the charger testing circuitry and configured to measure a voltage in the charger testing circuitry when the test load is supplied to the charging device, wherein when the measured voltage is above a threshold voltage level, the reader device is configured to provide a notification to a user indicating that the charging device is not suitable for use.

24. The reader device of claim 23, wherein when the measured voltage is below the threshold voltage level, the reader device is configured to display the analyte data.

25. The reader device of claim 23, wherein the charging device is a USB charger and the charger input comprises a USB input.

26. The reader device of claim 23, wherein the charger input is configured to receive a 5 V input.

27. The reader device of claim 23, wherein the control input is configured to provide a current to the charging device in a range of 650 mA to 1000 mA.

28. The reader device of claim 23, wherein the threshold voltage level is around 0 V.

29. The reader device of claim 23, wherein the control input is configured to cause the test load to be applied for a predetermined time period.

30. The reader device of claim 23, wherein the control input causes the test load to be applied by generating a resistance load in the charger testing circuitry.

31. The reader device of claim 30, wherein the measuring device is configured to measure the voltage across the resistance load.

32. The reader device of claim 23, wherein when the measured voltage is above a threshold voltage level, the reader device is configured to prevent the charging device from charging the rechargeable power source.

33. The reader device of claim 23, wherein the charger testing circuitry further comprises one or more field effect transistors.

34. The reader device of claim 33, wherein the charger testing circuitry comprises: a first field effect transistor; and a second field effect transistor, wherein the first field effect transistor and the second field effect transistor are inactive before the test load is applied and are activated via the control input.

35. The reader device of claim 34, wherein the first field effect transistor is in electrical communication with the charger input and with a first resistor, wherein the first resistor is positioned between the first field effect transistor and the second field effect transistor.

36. The reader device of claim 35, wherein the measuring device is configured to measure the voltage in the charger testing circuitry between the first field effect transistor and the first resistor.

37. The reader device of claim 35, further comprising a second resistor positioned between the first resistor and the second field effect transistor, wherein the measuring device is configured to measure the voltage in the charger testing circuitry between the first resistor and the second resistor.

38. The reader device of claim 23, wherein the notification comprises one or more of a visual notification provided via the display of the reader device or an audible notification provided by the reader device.

39. The reader device of claim 23, wherein measuring device is a microcontroller.

40. The reader device of claim 39, wherein the microcontroller comprises an analog to digital converter.

41. The reader device of claim 23, wherein the measuring device is a comparator.

42. An analyte monitoring system, comprising: the reader device of claim 23; and an in vivo analyte monitoring device, comprising: an analyte sensor comprising a first portion configured to be arranged above a skin surface and a second portion configured to be arranged below the skin surface and in contact with a bodily fluid of the user to sense analyte levels; and sensor electronics coupled to the first portion of the analyte sensor, the sensor electronics comprising a processor and wireless communication circuitry for wirelessly communicating analyte data to the reader device.

43. A method of determining if a charging device is suitable for use with a reader device of an analyte monitoring system, the method comprising: receiving a charging input from the charging device connected to the reader device, wherein the reader device comprises a rechargeable power source configured to be charged by the charging device; applying a test load, using a control input of charger testing circuitry of the reader device, to the charging device; measuring a voltage in the charger testing circuitry by a measuring device of the reader device when the test load is provided to the charging device; and outputting a notification when the measured voltage is above a threshold voltage level indicating that the charging device is not suitable for use.

44. The method of claim 43, wherein if the measured voltage is at or below the threshold voltage level, the method further comprises: displaying analyte data on the display of the reader device, wherein the analyte data is collected by an in vivo analyte sensor.

45. The method of claim 43, wherein if the measured voltage is at or below the threshold voltage level, the method further comprises: charging the rechargeable power source of the reader device.

46. The method of claim 43, wherein the threshold voltage level is around 0 V.

47. The method of claim 43, wherein providing the test load comprises providing a current to the charging device in a range of 650 mA to 1000 mA.

48. The method of claim 43, wherein outputting the notification comprises displaying a visual notification on the display of the reader device.

49. The method of claim 43, wherein the voltage is measured by a microcontroller of the reader device.

50. The method of claim 43, wherein the test load is applied for a predetermined time period.

51. The method of claim 43, wherein applying the test load comprises generating a resistance load in the charger testing circuitry.

52. The method of claim 51, wherein measuring a voltage in the charger testing circuitry comprises measuring the voltage across the resistance load.

53. The method of claim 43, comprising preventing the charging device from charging the rechargeable power source when the measured voltage is above a threshold voltage level.

54. The method of claim 43, wherein the charger testing circuitry comprises a first field effect transistor and a second field effect transistor.

55. The method of claim 54, wherein the first field effect transistor is in electrical communication with the charger input and a first resistor positioned between the first field effect transistor and the second field effect transistor, and wherein the voltage is measured between the first field effect transistor and the first resistor.

56. A reader device for displaying analyte data, the reader device comprising: a housing; a charging port arranged on the housing, wherein the charging port is configured to engage with a charging device; a power source arranged within the reader device configured to be charged by the charging device when the charging device is engaged with the charging port; communication circuitry for receiving analyte data from a sensor control device comprising an in vivo analyte sensor; a display arranged on the housing for displaying at least a portion of the analyte data received from the sensor control device; charger testing circuitry configured to determine if the charging device is suitable for use with the reader device; and a short circuit detection assembly configured to detect a short circuit when the charging device is connected to the charging port, wherein the display is configured to provide a notification when a short circuit is detected or when the charging device is determined to be unsuitable for use with the reader device.

57. The reader device of claim 56, wherein the short circuit detection assembly comprises a first temperature sensor configured to measure a first temperature of the charging port, and wherein the short circuit is detected based on the first temperature.

58. The reader device of claim 57, wherein the short circuit detection assembly further comprises a second temperature sensor configured to measure a second temperature, wherein the second temperature is an internal temperature within the housing.

59. The reader device of claim 58, wherein the short circuit detection assembly comprises a processing device configured to detect a short circuit when a difference between the first temperature and the second temperature exceeds a temperature difference threshold.

60. The reader device of claim 58, wherein the short circuit detection assembly comprises a processing device configured to detect a short circuit when a difference between a rate of change of the first temperature and a rate of change of the second temperature exceeds a rate of change difference threshold.

61. The reader device of claim 56, wherein the charger testing circuitry comprises a control input configured to cause a test load to be applied to the charging device.

62. The reader device of claim 61, wherein the reader device comprises a measuring device in communication with the charger testing circuitry, wherein the measuring device is configured to measure a voltage in the charger testing circuitry when the test load is supplied to the charging device.

63. The reader device of claim 62, wherein the reader device determines that the charging device is suitable for use with the reader device when the voltage measured is below or equal to a threshold voltage.

64. The reader device of claim 56, wherein the charger testing circuitry comprises one or more field effect transistors.

65. The reader device of claim 56, wherein the reader device is configured to display the analyte data received from the sensor control device when the charger testing circuitry determines that the charging device is suitable for use with the reader device.

66. A method for detecting a short circuit at a charging port of a reader device configured to display analyte data, the method comprising: receiving, by communication circuitry of the reader device, the analyte data from a sensor control device comprising an in vivo analyte sensor; displaying, by a display of the reader device, at least a portion of the analyte data received from the sensor control device; determining, by charger testing circuitry, if a charging device connected to a charging port of the reader device is suitable for use with the reader device; and monitoring, by a short circuit detection assembly, for a short circuit at the charging port of the reader device; and outputting a notification on the display of the reader device when the charging device is not suitable for use with the reader device or when a short circuit is detected.

67. The method of claim 66, wherein monitoring for a short circuit comprises measuring a temperature of the charging port by a first temperature sensor of the short circuit detection assembly.

68. The method of claim 67, wherein monitoring for a short circuit comprises measuring a second temperature that is a temperature within the reader device by a second temperature of the short circuit detection assembly.

69. The method of claim 68, wherein monitoring for a short circuit comprises determining, by a processing device of the short circuit detection assembly, a difference between the first temperature and the second temperature, wherein a short circuit is detected when the difference exceeds a temperature difference threshold.

70. The method of claim 68, wherein monitoring for a short circuit comprises determining, by a processing device of the short circuit detection assembly, a difference between a rate of change of the first temperature and a rate of change of the second temperature, wherein a short circuit is detected when the difference exceeds a rate of change difference threshold.

71. The method of claim 66, wherein determining if a charging device connected to a charging port of the reader device is suitable for use with the reader device comprises applying a test load by a control input of charger testing circuitry to the charging device.

72. The method of claim 71, further comprising measuring a voltage in the charger testing circuitry when the test load is applied to the charger testing circuitry.

73. The method of claim 72, further comprising determining that the charging device is suitable for use with the reader device when the voltage measured is below or equal to a voltage threshold.

74. The method of claim 66, wherein the charger testing circuitry comprises one or more field effect transistors.

75. The method of claim 66, further comprising displaying the analyte data received from the sensor control device when the charger testing circuitry determines that the charging device is suitable for use with the reader device.