Analyte sensor configuration and calibration based on data collected from previously used analyte sensors

Abstract

Disclosed herein is a method for automatically initializing an analyte sensor for a user. A first analyte sensor is operated in a first measurement mode to generate a first sensor signal indicative of an analyte level of the user. A second analyte sensor is deployed to measure the analyte level of the user and is operated in an initialization mode while simultaneously operating the first analyte sensor in the first measurement mode to receive sensor configuration data generated by the first analyte sensor. While operating the second analyte sensor in the initialization mode, the second analyte sensor is calibrated using at least some of the received sensor configuration data. Following the calibration, operation of the second analyte sensor is transitioned from the initialization mode to a second measurement mode, during which the second analyte sensor generates a second sensor signal indicative of the analyte level of the user.

Description

Technical Field

[0001] Embodiments of the subject matter described herein generally relate to analyte sensors for monitoring a user's physiological characteristics, such as blood glucose levels. More particularly, the disclosed subject matter relates to analyte sensor devices and related operating methods for initializing and calibrating analyte sensor devices when newly deployed. Background Art

[0002] The prior art includes a wide variety of medical devices and assemblies, as well as related methods of operation. For example, physiological analyte sensors are commonly known in the art for use in a variety of specialized applications. In this regard, thin-film electrochemical sensors are used to test a patient's analyte levels. More specifically, thin-film sensors have been designed to obtain an indication of blood glucose (BG) levels in diabetic patients and monitor BG levels, with the distal segment of the sensor positioned subcutaneously in direct contact with the patient's extracellular fluid. Such readings are particularly useful for regulating treatment regimens, which often include regular insulin administration to the patient.

[0003] Conventional glucose sensor sets typically include three main components: a disposable sensor with a mounting base; a durable, rechargeable transmitter that couples to the sensor; and a sensor insertion tool. The sensor assembly must be replaced periodically, typically about once a week, once every ten days, etc. When the sensor assembly is replaced, the user pauses any continuous glucose monitoring to charge the transmitter and prepare the new sensor assembly for use. The sensor insertion process is often lengthy and complex. In some cases, the user may need to wait for over an hour for the new sensor to be ready to provide glucose readings, which can interrupt the monitoring process. In addition, newly deployed glucose sensors must be calibrated against a reliable blood glucose measurement baseline, such as a fingerstick blood sample or an accurate and reliable glucose sensor reading.

[0004] Therefore, it is desirable to provide an improved analyte sensor device and a more convenient and efficient sensor deployment method that makes it easier and less time-consuming to deploy and use a new sensor to replace an old one. In addition, other desirable features and characteristics will become apparent from the following detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. Summary of the Invention

[0005] Disclosed herein is a method for automatically initializing an analyte sensor for a user. An exemplary embodiment of the method involves the following steps: operating a first analyte sensor in a first measurement mode to generate a first sensor signal indicative of an analyte level of the user; deploying a second analyte sensor to measure the analyte level of the user; concurrently with operating the first analyte sensor in the first measurement mode, operating the second analyte sensor in an initialization mode to receive sensor configuration data generated by the first analyte sensor; during operation of the second analyte sensor in the initialization mode, calibrating the second analyte sensor using at least some of the received sensor configuration data; and, after calibration, transitioning operation of the second analyte sensor from the initialization mode to a second measurement mode, during which the second analyte sensor generates a second sensor signal indicative of the analyte level of the user.

[0006] Also disclosed herein is an analyte sensor device. An exemplary embodiment of the sensor device includes: a housing; an electronics assembly within the housing; and a sensor element extending from the housing and electrically coupled to the electronics assembly, wherein when the analyte sensor device is deployed at a user, the sensor element provides a sensor signal indicative of an analyte level of the user. The electronics assembly includes at least one processor device and a non-transitory processor-readable medium operably associated with the at least one processor device. The processor-readable medium stores executable instructions that are configurable to cause the at least one processor device to perform a method comprising the following steps: activating an initialization mode of the analyte sensor device; while operating the analyte sensor device in the initialization mode, receiving sensor configuration data for processing by the electronics assembly, the sensor configuration data originating from a second analyte sensor device deployed at the user or previously deployed at the user; while operating the analyte sensor device in the initialization mode, configuring at least one sensor parameter of the analyte sensor device based on the received sensor configuration data; and after configuration, transitioning operation of the analyte sensor device from the initialization mode to a measurement mode, during which the analyte sensor device generates a sensor signal indicative of an analyte level of the user.

[0007] Another method for automatically initializing an analyte sensor for a user is also disclosed herein. An exemplary embodiment of the method involves the following steps: activating a new analyte sensor to measure an analyte level of a user; receiving sensor configuration data at the new analyte sensor while operating the new analyte sensor in an initialization mode, the sensor configuration data originating from an old analyte sensor deployed at the user or previously deployed at the user; configuring at least one sensor parameter of the new analyte sensor based on the received sensor configuration data while operating the new analyte sensor in the initialization mode; and, after configuring, transitioning operation of the new analyte sensor from the initialization mode to a first measurement mode, during which the new analyte sensor generates a first sensor signal indicative of the analyte level of the user.

[0008] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] A more complete understanding of the subject matter may be derived by referring to the detailed description and claims when considered in conjunction with the following drawings, wherein like reference numerals refer to like elements throughout.

[0010] Figure 1 is a simplified block diagram representation of a medical device system configured, arranged and operative in accordance with an exemplary embodiment of the present invention;

[0011] Figure 2 is a perspective top view of an exemplary embodiment of an analyte sensor device;

[0012] Figure 3 for Figure 2 a side view of the analyte sensor device shown;

[0013] Figure 4 For the Figure 1 A simplified block diagram representation of an exemplary embodiment of a computer-based or processor-based apparatus deployed in the illustrated system;

[0014] Figure 5 A flow chart illustrating an exemplary embodiment of a sensor initialization and calibration process;

[0015] Figure 6 A block diagram illustrating a device key management scheme; and

[0016] Figure 7 A block diagram illustrating the sensor pre-calibration scheme. DETAILED DESCRIPTION

[0017] The following detailed description is merely illustrative in nature and is not intended to limit the present subject matter or the embodiments of the present application or the application and use of such embodiments. As used herein, the word "exemplary" means "serving as an example, instance, or illustration." Any embodiment described herein as exemplary is not necessarily to be construed as superior to or preferable to other embodiments. Furthermore, the present invention is not intended to be bound by any express or implied theory presented in the foregoing technical field, background technology, summary of the invention, or the following detailed description.

[0018] Techniques and techniques may be described herein in terms of functional and / or logic block components, with reference to symbolic representations of operations, processing tasks, and functions that may be performed by various computing components or devices. Such operations, tasks, and functions are sometimes referred to as being computer-executed, computerized, software-implemented, or computer-implemented. It should be understood that the various block components shown in the figures may be implemented by any number of hardware, software, and / or firmware components configured to perform the specified functions. For example, embodiments of a system or component may employ various integrated circuit components, such as memory elements, digital signal processing elements, logic elements, and lookup tables, which may perform various functions under the control of one or more microprocessors or other control devices.

[0019] When implemented in software or firmware, the various elements of the systems described herein are essentially code segments or instructions that perform various tasks. In some embodiments, the programs or code segments are stored on a tangible processor-readable medium, which can include any medium capable of storing or transmitting information. Examples of non-transitory and processor-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, and hard disks.

[0020] The subject matter described herein relates to physiological analyte sensor devices and related operating methods. The non-limiting exemplary embodiments described below relate to continuous glucose sensors of the type used by diabetic patients. It should be understood that the concepts, operating methods, and calibration techniques described herein are not necessarily limited to use with glucose sensors, and in fact, the concepts and techniques described with reference to glucose sensors may also be used with other medical devices, other sensor types, other medical components or supplies, etc.

[0021] For the sake of brevity, conventional aspects and technologies related to glucose sensors and glucose sensor manufacturing may not be described in detail here. The glucose sensor of the type described here can be implemented as an electrochemical sensor using glucose oxidase. Sensors that use glucose oxidase to react glucose and oxygen are known, and such glucose sensors will not be described in detail here. In this regard, known and / or conventional aspects of glucose sensors and their manufacture can be, but are not limited to, the types described below: U.S. Patents No. 5,391,250, No. 6,892,085, No. 7,468,033 and No. 7,602,310; and U.S. Patent Application Nos. 2009 / 0299301 and 2017 / 0290535 (each of which is incorporated herein by reference).

[0022] Figure 1 1 is a simplified block diagram representation of a medical device system 100 configured, arranged, and operated in accordance with an exemplary embodiment of the present invention. The system 100 supports a user 102 of a medical device 104 that regulates the delivery or administration of a drug to the user 102. Although not always required, the medical device 104 may include or cooperate with a therapy delivery unit 106 that is attached to, worn by, or implanted in the body of the user 102 to facilitate drug delivery to the user 102. The medical device 104 includes or cooperates with an analyte sensor device that measures an analyte level of the user 102. In practice, the analyte sensor device is a disposable component that must be replaced periodically. Therefore, Figure 1 An old analyte sensor device 108 (a first analyte sensor) and a new analyte sensor device 110 (a second analyte sensor) are depicted, with the new analyte sensor device 110 replacing the old analyte sensor device 108 at the appropriate time. Figure 1 The illustrated embodiment of the system 100 also includes or cooperates with an intermediary device 112 having one or more software applications that support the techniques and methods described in greater detail herein. The intermediary device 112 can be implemented as a mobile computing device, a smartphone, a patient monitoring device, a wearable computing device such as a smartwatch, a video gaming device, a media player device, a medical device, and the like. In some embodiments, if the medical device 104 includes the features and functionality of the intermediary device 112, then the system 100 need not include the intermediary device 112. In other words, the medical device 104 can also serve as an intermediary device.

[0023] According to the non-limiting example described herein, the medical device 104 is implemented as a drug infusion device configured to regulate the delivery of a drug fluid to the user 102, wherein the therapeutic delivery unit 106 is implemented as a fluid delivery cannula or needle disposed in the skin or body of the user 102. The medical device 104 regulates the delivery of the drug to the user based on the sensor signal provided by the analyte sensor device. In certain embodiments, the medical device 104 is an insulin infusion device, the therapeutic delivery unit 106 is a disposable / replaceable insulin infusion device that is fluidically coupled to the insulin infusion device, and the analyte sensor devices 108 and 110 are continuous glucose sensor devices. In this case, the insulin infusion device, the glucose sensor device, and the infuser are components of an insulin infusion system used by a patient to treat diabetes.

[0024] At least some components of the system 100 are communicatively coupled to one another to support data communication as needed. For this particular example, the medical device 104 can communicate wirelessly with the analyte sensor devices 108 and 110 via a suitable data communication link and communication protocol. In addition, the intermediate device 112 can communicate wirelessly with the analyte sensor devices 108 and 110 via a suitable data communication link and communication protocol. In certain embodiments, the analyte sensor devices 108 and 110 can communicate directly with each other wirelessly via a suitable data communication link and communication protocol. Other configurations and topologies are also contemplated herein, such as systems that include additional intermediate, interface, or data forwarding devices in the data path between the transmitting device and the receiving device.

[0025] Depending on the particular embodiment and application, the system 100 may include or cooperate with other devices, systems, and sources of input data. For example, in some embodiments, the system 100 includes one or more sources of contextual information or data, which may include, but are not limited to: an activity tracker device or application; a meal logging device or application; a mood tracking device or application; and the like.

[0026] Figure 1 The network communication links are depicted in a simplified manner. In practice, system 100 can collaborate with and utilize any number of wireless data communication networks and any number of wired data communication networks maintained or operated by various entities and providers. Therefore, communications between the various components of system 100 may involve multiple network links and different data communication protocols. In this regard, the networks may include, but are not limited to, any of the following: a local area network; a wide area network; the Internet; a personal area network; a near-field data communication link; a cellular communication network; a satellite communication network; a video service or television broadcast network; an in-vehicle network; etc. The components of system 100 can be appropriately configured to support the various wireless and wired data communication protocols, techniques, and technologies required for compatibility with the network infrastructure.

[0027] Figure 2 is a perspective top view of an exemplary embodiment of an analyte sensor device 200 suitable for use with the medical device system 100, and Figure 3 2 is a side view of an analyte sensor device 200. The illustrated embodiment of the analyte sensor device 200 includes a housing 202 having an upper housing 204 with an upper main wall within the interior of the upper housing 204 and a lower housing 206 with a lower main wall within the interior of the lower housing 206, wherein the upper and lower main walls are opposed to each other. The housing 202 is generally shown as rectangular, but other shapes, such as square, circular, polygonal, may be used depending on the size of the components housed therein and to increase comfort on the skin. The housing 202 has a low profile to reduce visibility through clothing and also to reduce discomfort and interference from the sensing device when worn on the patient's skin.

[0028] Housing 202 is attached to adhesive patch 210 for press-bonding installation on the user's skin. The size of patch 210 can be designed so that it has as much adhesion as possible to the skin, while not being too large to be uncomfortable or not easily fitting the patient. It should be understood that, in addition to adhesive patch 210, alternative methods or technologies for attaching housing 202 to the patient's skin can also be envisioned. Housing 202 can be made of suitable hard plastic that can safely and securely hold the electrical components of sensor device 200. In this configuration, upper housing 204 includes a small opening 212 for a battery pull tab (not shown) to pass through, which is used to prevent internal batteries from contacting the electronic battery contacts before use, thereby preventing battery exhaustion and preventing premature activation of the analyte sensor device. In certain embodiments, the removal of the pull tab causes sensor device 200 to activate or enter initialization mode (described in more detail below).

[0029] Adhesive patch 210 can be bonded to lower housing 206 along the entire footprint of lower housing 206 or only on a portion, such as the perimeter of lower housing 206. Patch 210 can be ultrasonically welded to lower housing 206 or adhered, for example, by a double-sided adhesive. In some configurations, adhesive patch 210 extends further than the edge of lower housing 206.

[0030] Figure 3 2 shows a side view of an analyte sensor device 200, wherein a thin film sensor element 220 extends from the housing 202 and through a patch 210, which may include a hole for the sensor element 220 to pass through. Figure 3As shown, the sensor element 220 comprises a relatively thin and elongated element that can be constructed according to so-called thin mask technology to include an elongated conductive element embedded or coated between layers of a selected insulating sheet material, such as a polyimide film or sheet. The proximal end or head of the sensor element 220 is relatively enlarged and defines a portion for electrically coupling to an electronic assembly 224 located within the housing 202 (at Figure 3 ). The opposite or distal segment of sensor element 220 includes a plurality of exposed sensor electrodes for contacting bodily fluids and / or tissue when the distal sensor segment is placed within the user's body. The sensor electrodes transmit a sensor signal representative of the measured analyte level of interest. Thus, when analyte sensor device 200 is deployed on a user, sensor element 220 provides a sensor signal indicative of the user's analyte level.

[0031] The sensor signal is transmitted in a continuous manner from the analyte sensor device 200 (which includes a wireless transmitter) to an appropriate destination device for recording, processing, and / or display as a monitored patient condition. Figure 1 , the analyte sensor device 200 can be suitably configured to transmit the sensor signal to the medical device 104, the intermediate device 112, and / or another sensor device. Further description of this general type of flexible thin film sensor can be found in U.S. Patent No. 5,391,250, which is incorporated herein by reference. For example, sensor electronics including a wireless transmitter are discussed in U.S. Patent No. 7,602,310, which is incorporated herein by reference.

[0032] According to certain embodiments, the medical device 104, the intermediate device 112, and each analyte sensor device 108, 110 may be implemented as a computer-based or processor-based device, system, or component having suitably configured hardware and software written to perform the functions and methods required to support the features described herein. In this regard, Figure 4 Suitable for deployment in Figure 1 A simplified block diagram representation of an exemplary embodiment of a computer-based or processor-based device 400 in the system is shown.

[0033] The illustrated embodiment of device 400 is intended to serve as a high-level and general representation of a suitable platform. In this regard, any computer-based or processor-based component of system 100 may utilize the architecture of device 400. The illustrated embodiment of device 400 generally includes, but is not limited to: at least one processor device 402; a suitable amount of memory 404; device-specific hardware, software, firmware, user interface (UI), and / or features 406; a power source 408, such as a disposable or rechargeable battery; a communication module 410; and a display element 412. Of course, an implementation of device 400 may include additional elements, components, modules, and functionality configured to support various features unrelated to the subject matter described herein. For example, device 400 may include certain features and elements to support general functionality that may be related to the specific implementation and deployment of device 400. In practice, the elements of device 400 may be coupled together via a bus or any suitable interconnection architecture 414.

[0034] The processor device 402 may be implemented or executed using a general purpose processor, a content addressable memory, a digital signal processor, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. Furthermore, the processor device 402 may be implemented as a combination of computing devices, such as a combination of a digital signal processor and a microprocessor, a combination of multiple microprocessors, a combination of one or more microprocessors in conjunction with a digital signal processor core, or any other such configuration.

[0035] Memory 404 may be implemented as RAM memory, flash memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. In this regard, memory 404 may be coupled to processor device 402 so that processor device 402 can read information from and write information to memory 404. Alternatively, memory 404 may be integral to processor device 402. As an example, processor device 402 and memory 404 may reside in an ASIC. At least a portion of memory 404 may be implemented as computer storage media operatively associated with processor device 402, such as a tangible computer-readable medium having computer-executable instructions stored thereon. When read and executed by processor device 402, the computer-executable instructions cause device 400 to perform certain tasks, operations, functions, and processes specific to a particular embodiment. In this regard, memory 404 may represent one suitable embodiment of such a computer-readable medium. Alternatively or additionally, the apparatus 400 may receive and cooperate with a computer-readable medium (not separately shown) implemented as a portable or mobile component or platform, such as a portable hard drive, USB flash drive, optical disk, or the like.

[0036] The device-specific hardware, software, firmware, UI, and features 406 may vary from one embodiment of the device 400 to another. For example, the device-specific hardware, software, firmware, UI, and features 406 will support: medical device operations when the device 400 is implemented as a medical device (e.g., an insulin infusion pump); smartphone features and functions when the device 400 is implemented as a smartphone; sensor operations and features when the device 400 is implemented as an analyte sensor, etc. In practice, certain portions or aspects of the device-specific hardware, software, firmware, UI, and features 406 may be implemented in different embodiments. Figure 4 is implemented in one or more other blocks depicted.

[0037] If present, the UI of device 400 may include or cooperate with various features to allow a user to interact with device 400. Thus, the UI may include various human-machine interfaces, such as a keypad, keys, keyboard, buttons, switches, knobs, touchpad, joystick, pointing device, virtual tablet, touch screen, microphone, or any device, component, or function that enables a user to select options, enter information, or otherwise control the operation of device 400. The UI may include one or more graphical user interface (GUI) control elements that enable a user to manipulate or otherwise interact with applications via display element 412.

[0038] The communication module 410 facilitates data communication between the device 400 and other components as needed during operation of the device 400. In the context of this specification, the communication module 410 may be used to transmit or stream device-related control data, patient-related data, device-related status or operating data, treatment recommendations, infusion device adjustment recommendations, and related control instructions, etc. It should be understood that the specific configuration and functionality of the communication module 410 may vary depending on the hardware platform and specific implementation of the device 400. Therefore, reference is made to Figure 1, the communication module of the intermediate device 112 can be used to receive and transmit sensor data. In addition, the communication module of the medical device 104 can be used to receive sensor data from the active analyte sensor devices 108, 110. In practice, embodiments of the device 400 can use various data communication protocols to support wireless data communication and / or wired data communication. For example, the communication module 410 can support one or more wireless data communication protocols, technologies, or methods, including but not limited to: RF; IrDA (infrared); Bluetooth; Bluetooth Low Energy (BLE), ZigBee (and other variants of the IEEE 802.15 protocol); IEEE 802.11 (any variant); IEEE 802.16 (WiMAX or any other variant); direct sequence spread spectrum; frequency hopping spread spectrum; cellular / wireless / cordless telecommunication protocols; wireless home network communication protocols; paging network protocols; magnetic induction; satellite data communication protocols; wireless hospital or health care facility network protocols, such as those operating in the WMTS band; GPRS; and proprietary wireless data communication protocols, such as variants of wireless USB. In addition, the communication module 410 may support one or more wired / cable data communication protocols, including but not limited to: Ethernet; power line; home network communication protocol; USB; IEEE 1394 (Firewire); hospital network communication protocol; and proprietary data communication protocols.

[0039] The display element 412 is suitably configured to enable the device 400 to present and display various screens, recommendation messages, notifications, GUIs, GUI control elements, drop-down menus, auto-fill fields, text entry fields, message fields, and the like. Of course, the display element 412 may also be used to display other information during operation of the device 400, as is well understood. It is noted that the specific configuration, operating characteristics, size, resolution, and functionality of the display element 412 may vary depending on the actual implementation of the device 400.

[0040] The disclosed subject matter relates to systems and related operating methods for initializing, configuring, and / or calibrating an analyte sensor device (e.g., a continuous glucose sensor) based on sensor data from a previously deployed sensor device of the same type. Continuous glucose monitoring sensors require a blood glucose measurement (sample) for calibration. However, fingerstick blood glucose measurements can be unpleasant and burdensome for patients. Disposable glucose sensor devices allow patients to receive uninterrupted sensor glucose data through a "sensor overlap," during which the patient deploys a new sensor and allows it to initialize and warm up while the existing sensor is still actively providing valid sensor glucose data. The methods described herein utilize sensor data from an old sensor device to calibrate and configure a new sensor device. During the sensor overlap period, the currently deployed (old) sensor provides sensor data received by the new sensor. The disclosed system may use an intermediate communication device to facilitate the transmission of sensor data, or it may use direct communication between the two sensor devices. The new sensor device uses the received sensor data to perform initial calibration and / or configuration of sensor operating parameters without requiring a new blood glucose sample.

[0041] The disclosed method improves the patient experience by reducing the number of fingertip measurements and by reducing the amount of patient interaction required to activate newly deployed sensors. Furthermore, the disclosed method reduces the time the user is out of treatment. As explained in more detail below, the user receives uninterrupted sensor readings and can therefore remain in automatic (closed-loop treatment) operation mode while new sensors are deployed.

[0042] The disclosed systems and methods can also be used to transmit sensor data for use with features and operations other than sensor calibration. For example, the received sensor data can be used to reduce the duration of sensor initialization or warm-up, improve sensor accuracy and user features, and detect out-of-the-box inconsistencies or inaccuracies in newly deployed sensors. In certain embodiments, the disclosed subject matter is applicable to continuous glucose sensor-enabled insulin infusion pump systems and stand-alone continuous glucose monitoring systems. Furthermore, the disclosed subject matter can be used with any appropriately configured medical device system that includes or cooperates with a disposable sensor device.

[0043] Figure 5 A flow chart illustrating an exemplary embodiment of a sensor initialization and calibration process 500; the various tasks performed in conjunction with process 500 may be performed by software, hardware, firmware, or any combination thereof. For illustrative purposes, the following description of process 500 may refer to the preceding description of process 500 in conjunction with FIG. Figure 1-4 In practice, portions of process 500 may be performed by different elements of the described system, such as sensor devices, medical devices, intermediary devices, smartphone applications, etc. It should be understood that process 500 may include any number of additional or alternative tasks, Figure 5 The tasks shown do not have to be performed in the order illustrated, and process 500 may be incorporated into a more comprehensive program or process having additional functionality not described in detail herein. Furthermore, various embodiments of process 500 may be omitted from an embodiment of process 500 as long as the intended overall functionality remains intact. Figure 5 One or more tasks as shown.

[0044] Process 500 assumes that a first (old) analyte sensor device is operating when deployed at a user (task 502). More specifically, the old analyte sensor device is operating in a measurement mode to generate a corresponding sensor signal indicative of the user's analyte level. While operating in the measurement mode, the sensor signal generated by the old analyte sensor device can be stored in the old analyte sensor device, transmitted to a medical device, transmitted to an intermediary device, uploaded to a cloud-based computing device, etc.

[0045] Process 500 continues by deploying the second (new) analyte sensor device to measure the user's analyte level (task 504). For this example, the new analyte sensor device is deployed on the user's body by using the insertion assembly of traditional insertion technology. The new analyte sensor is deployed and ready to use, and the old analyte sensor device remains on the measurement mode and operates. In conjunction with the deployment of the new analyte sensor, process 500 pairs the new analyte sensor device with an intermediate device and / or a medical device (task 506), and activates the initialization mode (task 508) of the new analyte sensor. The pairing of the new analyte sensor device has established a secure data communication link to promote sensor configuration data to be transmitted from the intermediate device to the new analyte sensor device, and to promote sensor data to be transmitted from the new analyte sensor device to the intermediate device (if desired).

[0046] Process 500 operates two analyte sensor devices simultaneously during an "overlap" period (task 510). The simultaneous overlap period corresponds to the operation of the old analyte sensor device in its measurement mode and the operation of the new analyte sensor in its initialization mode or after initialization mode. After the new analyte sensor device enters initialization mode, it can communicate its "warm-up" status to a target device, such as an intermediate device. The intermediate device can respond to the communicated status by requesting information from the old analyte sensor device. Therefore, during this simultaneous overlap period, the new analyte sensor device receives sensor configuration data generated by the old analyte sensor device (task 512). For the exemplary embodiment presented here, the new analyte sensor device receives the sensor configuration data indirectly via the intermediate device (which can serve as a data pass-through component in this context). However, in other embodiments, the new analyte sensor device receives the sensor configuration data directly from the old analyte sensor device according to a secure point-to-point data communication protocol. Therefore, the sensor configuration data from the old analyte sensor device is transmitted to the new analyte sensor device for processing, disposal, and storage as needed.

[0047] Configuration / calibration data provided with the old analyte sensor unit may include any of the following information, but is not limited to:

[0048] One or more previous measurement samples and their age relative to a calibration transfer time (absolute time (UTC), device (CGM or pump) reference time, etc.). The calibration transfer time is defined as the time to retrieve calibration data from the old sensor device. In some embodiments, data must be retrieved from the old sensor device and written to the new sensor device within a fixed or predetermined validity time window. Timing data is not adjusted to compensate for the time that elapses between these events. In other embodiments, the display device may adjust the timing information for each sample to compensate for the extended period that elapses between the two data exchange events (retrieval and transmission from the old sensor device to the new sensor device).

[0049] One or more previously measured samples and their age relative to a sensor reference time (sensor start time or other period known only to the old sensor device). The retrieved data may also include a calibration transmission time relative to the sensor reference time. In some embodiments, data must be retrieved from the old sensor device and written to the new sensor device within a fixed or predetermined validity time window. The timing data is not adjusted to compensate for the time that elapsed between these events. In other embodiments, the display device may adjust the calibration transmission time information or the timing information for each sample to compensate for the extended period that elapsed between two data exchange events (retrieval and transmission from the old sensor device to the new sensor device).

[0050] One or more previous measurement samples with absolute timestamps. These timestamps can be in the time scale maintained by the display device, or in a global time reference (UTC, Unix epoch time, etc.).

[0051] One or more previously measured samples for which there is no timing information.

[0052] One or more previous measurement samples with a predetermined time interval (e.g., a series of measurements at 30 minute intervals).

[0053] Additional context, status, or device health data.

[0054] The measurement samples may include but are not limited to any of the following: glucose concentration from blood; glucose concentration from interstitial fluid; glucose concentration change rate data; sensor current value; sensor electrode voltage; EIS results; other status data from the sensor device.

[0055] Reference again Figure 5 While the new analyte sensor device is operating in its initialization mode and while the old analyte sensor device is operating in its measurement mode, process 500 continues by configuring at least one sensor parameter of the new analyte sensor device (task 514). Configuring the new analyte sensor device is based on at least some of the received sensor configuration data. In this case, the received sensor configuration data is used to adjust settings, modify control algorithms or adjust algorithm constants or factors, adjust preferences, and / or adjust certain variables that affect the performance, output, or operation of the new analyte sensor device. For the exemplary embodiments described herein, the configuration performed at task 514 includes calibrating the new analyte sensor device using at least some of the received sensor configuration data.

[0056] In certain embodiments, the new analyte sensor device reviews the received sensor configuration data to determine whether the data can be used for calibration. If the received data is suitable for calibration, the sensor calibration continues with the received data. If the new analyte sensor device determines that the received data is defective, unsuitable for calibration, or should be supplemented, it may generate an instruction or message prompting calibration according to conventional methods (e.g., obtaining an analyte sample from the user). Checking the received sensor configuration data may involve applying a validity test to the data or its associated metadata (such as a timestamp). In practice, the determination may be related to a specific sensor algorithm. For example, the algorithm may perform a calibration error check to see if the old sensor glucose sample is divided by the sensor current signal (commonly referred to as ISIG) to determine if the ratio is within a specific range. It may also compare this ratio with other known ratios (e.g., for previous sensors). It may also check whether the calibrated ISIG is above / below a certain range. These and other technologies may be used for this function.

[0057] Initially, process 500 assumes that the measurements generated by the two sensors are within the actual operating tolerance of each other, e.g., less than 10% difference. Therefore, the new sensor device can initially be trusted for treatment decisions. Furthermore, the existing sensor data generated by the old sensor device can be used as an accurate measurement of the target analyte level, so the new sensor device can be calibrated based on the existing sensor data (rather than based on a new sample from the user). Over time, the new sensor device can calibrate itself based on analyte samples collected from the user, but the initial calibration can be performed seamlessly, without delay, and with minimal user involvement.

[0058] In certain embodiments, the new analyte sensor device updates its status to indicate the completion of the configuration / calibration procedure. After completing the configuration / calibration, process 500 continues by converting the operation of the new analyte sensor device from its initialization mode to its measurement mode (task 516), during which the new analyte sensor device generates a sensor signal indicating the measured user's analyte level (e.g., blood glucose). Various manual or automatic triggers can be used to activate the switch from the old sensor device to the new sensor device. For example, the old sensor device expires, the user initiates a sensor change, or a time-based trigger can be implemented. It is worth noting that the generated sensor signal has been calibrated to some extent, and the continued operation of the new analyte sensor device in its measurement mode may include further calibration based on an analyte sample obtained from the user, such as a fingertip blood glucose measurement. After switching to the measurement mode of the new analyte sensor device, the operation of the old analyte sensor device can be terminated (task 518). Task 518 can be automatically controlled by one or both of the sensor devices, the linked medical device, and / or the linked intermediate device. Alternatively, task 518 may be automatically executed when the old analyte sensor device is removed from the user's body, when it is unpaired from an intermediate device, when it loses data connectivity with the new analyte sensor device, etc. Thereafter, only the new analyte sensor device remains deployed, operating in its normal measurement mode. In the case of an insulin infusion system including a continuous glucose sensor, process 500 allows the new sensor device to be quickly and conveniently initialized without requiring a blood sample, and to operate in a manner that does not cause the insulin infusion pump to pause or suspend certain operations, such as automatic closed-loop control.

[0059] Although sensor calibration is described above, the system 100 and process 500 can be used for other purposes with sensor devices that do not require user calibration, such as factory-calibrated sensor devices. In this regard, even if the sensor devices do not require calibration, the transmission of sensor data between the two sensor devices can be used to improve sensing accuracy, reduce warm-up time, or otherwise improve sensor device performance.

[0060] As explained above, system 100 and process 500 support different possible device topologies and arrangements. According to an exemplary embodiment, an intermediate device with a display serves as a communication path for the two sensor devices, while also serving as the primary display and user interface for the user. In an alternative embodiment, the intermediate device serves only as a display / interface device for the user, while the two sensor devices communicate directly with each other. In another embodiment, system 100 need not include a display device or an intermediate device. In such an embodiment, the two sensor devices communicate directly with each other. It should be understood that other configurations and topologies can also be deployed with system 100 if desired.

[0061] Data integrity

[0062] The configuration / calibration data may be transmitted in an unencrypted manner, for example, as plain text. Alternatively, the configuration / calibration data may be partially or fully encrypted to protect the data from interception by unauthorized parties. Some possible implementations include, but are not limited to, the following:

[0063] The old sensor device provides a data block to the display device, encrypted using a first encryption key known to both the old sensor device and the display device. Upon receiving the data, the display device decrypts the data. Before transmitting the data to the new sensor device, the display device may re-encrypt the data using a second encryption key known to both the display device and the new sensor device. Upon receiving the data, the new sensor device decrypts the data.

[0064] The old sensor device provides a block of data encrypted using a key unknown to the display device but known to the new sensor device. The display device transmits the encrypted data to the new sensor device. The new sensor device decrypts the data upon receipt. This embodiment prevents the display device from inspecting or altering the content of the sensor-provided data.

[0065] The old sensor device transmits the data block directly to the new sensor device. The data is encrypted using a key known to both sensor devices.

[0066] Configuration / calibration data can include a checksum or hash to protect the data from corruption. Configuration / calibration data can include a cryptographic signature to protect the data from tampering. The signature can be calculated using symmetric or public key cryptography. Calibration data can include a validity timestamp to allow a display device or new sensor device to reject data that exceeds its lifetime limit.

[0067] Automatic wireless pairing

[0068] As explained above, a wireless transmitter may be needed to send readings from the glucose sensor to an insulin pump or smartphone (e.g., using the Bluetooth wireless data communication standard). The transmitter is paired with the pump or smartphone through user input. According to conventional designs, the RF transmitter is mechanically attached to the glucose sensor. When the sensor expires (e.g., in one to two weeks), the RF transmitter is mechanically connected to a new sensor. According to modern sensor designs, the RF transmitter is built into the glucose sensor, resulting in advantages associated with a smaller form factor. When the sensor expires, the user must unpair the RF transmitter from the pump (or smartphone) and pair a new RF transmitter before starting to use the new sensor.

[0069] In some implementations, the user must first unpair the RF transmitter from the pump. Next, the user can pair a new transmitter. After the RF pairing is complete, the user can initialize and calibrate the new sensor. This step can take up to two hours. This weekly (or biweekly) pairing process adds a burdensome process to maintaining blood glucose control while switching to a new sensor. These mandatory steps can result in hours without sensor protection to prevent hypoglycemia (e.g., "Suspend on Low" technology), and the pump cannot provide closed-loop therapy without a calibrated sensor. Therefore, in these cases, having an RF transmitter for each glucose sensor may not benefit the user.

[0070] Given that both the RF transmitter and glucose sensor can be implemented using the same disposable device, a secure and seamless sensor management solution is proposed. This results in less user burden, increased hypoglycemia protection, and data collection for sensor quality control compared to existing offerings. The proposed approach employs software-based device key management and assumes the insulin pump (or smartphone) has a linked user account (e.g., one suitable for use with patient status monitoring or recordkeeping).

[0071] Feature 1: When a user account orders a new sensor, the factory provides the serial number of the factory sensor to the secure account server. This secure server generates an encryption key for each serial number and provides it to the linked insulin pump (or smartphone). In this regard, Figure 6 FIG6 is a block diagram illustrating a device key management scheme 600. For this example, a user 602 or user account generates a request 603 or orders a new sensor by contacting a helpline 604. The request 603, which may include a user or account identifier, is forwarded to a shipping center 606. The shipping center 606 provides the serial number 608 of the shipped sensor device (along with the user / account identifier) ​​to a secure account server 610. The server 610 responds by sending an encrypted authorization key for each sensor device to an insulin pump or smartphone 612 linked to the user / account identifier.

[0072] Feature 2: When a new sensor device is attached to a user's body, it enters "search mode" by broadcasting its serial number in an encrypted format. Only devices that have been pre-assigned a matching key can successfully reply, ending search mode. This increases the security required to pair a new sensor device with another without user interaction.

[0073] Feature 3: A newly paired sensor begins its warm-up silently and does not request calibration, unless the previous sensor has expired. Therefore, the new sensor is deployed while the old sensor remains active, and the two sensors operate in an "overlap" mode for a period of time. If the user provides a blood glucose value, this calibrates the new sensor. After the new sensor is successfully calibrated, the user is notified that they can remove the old sensor. In practice, this notification can occur via a single display screen or message on the infusion pump or monitoring device. In contrast, the conventional procedure of replacing an old glucose sensor device can require extensive patient involvement and interaction with many different display screens.

[0074] Feature 4: Enhanced protection against low glucose states during sensor replacement. Given that a new sensor is inserted before the previous sensor expires, the insulin pump (or smartphone) shares the glucose values ​​of the old sensor with the new sensor. These shared glucose values ​​are used for pre-calibration, which is a sufficient state to provide low glucose detection from the new sensor (if the old sensor is expired). Therefore, if the user is sleeping, they can still receive an alert in response to a detected low glucose condition, and the insulin pump can continue to provide automatic pause therapy. The sensor glucose value of the pre-calibrated sensor is not displayed to the user. If a fingertip blood glucose value is provided to the pump (or smartphone), then that value can be provided to the new sensor for quick calibration. In this regard, Figure 7 FIG2 is a block diagram illustrating a sensor pre-calibration scheme 700. An old sensor device 702 sends its glucose value 703 to an insulin pump or smartphone 704, which forwards the glucose value 703 to a new sensor device 706 for use as a pre-calibration value. The new sensor device 706 uses the glucose value 703 to calibrate itself and generate its own glucose value 708 suitable for use by the insulin pump or smartphone 704 to provide low glucose protection for a period of time after the new sensor device 706 is deployed. Thus, even if the old sensor device 702 expires, the new sensor device 706 can provide adequate low glucose protection using the pre-calibration scheme.

[0075] Feature 5: The key provided to the insulin pump (or smartphone) for each sensor also includes the sensor's manufacturing date and location. If the sensor the user inserts is too old (expired), a warning is issued to the user. When each sensor expires (or is ready for replacement), a reason "code" is saved to the history (e.g., the user's account history). Thus, the parent company possesses the following quality control information: sensor serial number, manufacturing date, and location; sensor start date; sensor performance data; and the reason for sensor retirement or replacement.

[0076] Benefits and Results

[0077] Continuous glucose monitoring (CGM) is truly continuous: glucose alerts and hypoglycemia pauses remain active. There is no downtime for device removal, unpairing, pairing a new device, activating the sensor, warming up (which can typically take up to 2 hours), and calibration (which can typically take up to 12 minutes). This also provides more time for automated glucose control mode, potentially improving outcomes.

[0078] A user can install a new sensor before bed and trust that the "Pause until low" feature will work with both the expiring sensor and the new sensor.

[0079] Data collection is automated for end-to-end quality control of the sensors.

[0080] Automatic sensor switching eliminates a significant amount of user activity that occurs every 1-2 weeks. These changes significantly reduce work time and burden.

[0081] Device function

[0082] In some embodiments, the display device acts as a data pass-through device. It does not include logic for determining the validity of the calibration data. The new sensor device determines whether the calibration data meets the requirements for calibrating the new sensor device. In other embodiments, the display device may check the validity of the calibration data payload or augment it with additional information, such as data generated or maintained by the medical device, status data, etc. In other embodiments, the display device is not present in system 100.

[0083] Data transmission mechanism

[0084] Configuration / calibration data can be transmitted via a wireless network, such as a Bluetooth network link, Wi-Fi, or other technology. Data can also be transmitted via other wired or wireless communication methods. Data can be relayed through a display device or transmitted directly between two sensors. It can also be relayed through two different displays or intermediate devices (for example, when a patient uses one sensor device with an insulin infusion pump and wants to change to a second sensor device monitored by a smartphone).

[0085] Other applications

[0086] The data transfer mechanism and workflow described herein can be used in CGM systems that do not require end-user calibration data ("factory calibration"). For these systems, the transferred data can be used to improve the performance of new sensor devices. Possible applications include, but are not limited to, reducing the warm-up time of new sensor devices; improving the initial sensor measurement accuracy of new sensor devices; and detecting problems or performance issues with older sensor devices at an early stage.

[0087] Although at least one exemplary embodiment has been presented in the foregoing detailed description, it should be understood that there are a large number of variations. It should also be understood that the one or more exemplary embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter in any way. More precisely, the foregoing detailed description will provide a convenient guide for implementing the one or more described embodiments to those skilled in the art. It should be understood that various changes may be made to the function and arrangement of elements without departing from the scope defined by the claims, including known equivalents and foreseeable equivalents at the time of filing this patent application.

Claims

1. A method for automatically initializing an analyte sensor for a user, the method comprising the following steps: operating a first analyte sensor (108) in a first measurement mode to generate a first sensor signal indicative of an analyte level of the user; deploying a second analyte sensor (110) to measure the analyte level of the user; operating the second analyte sensor in an initialization mode while operating the first analyte sensor (108) in the first measurement mode to receive sensor configuration data generated by the first analyte sensor (108); determining, by the second analyte sensor, whether the received sensor configuration data is suitable for calibrating the second analyte sensor; as well as In response to determining that the received sensor configuration data is not suitable for calibrating the second analyte sensor, causing generation of a message prompting the user to obtain an analyte sample.

2. The method of claim 1, wherein the second analyte sensor (110) receives the sensor configuration data directly from the first analyte sensor (108).

3. The method of claim 1, wherein the second analyte sensor (110) receives the sensor configuration data from an intermediary device in communication with the second analyte sensor (110).

4. The method of claim 3, wherein the intermediate device comprises a drug infusion device configured to regulate drug delivery to the user based on a sensor signal generated by the first analyte sensor or the second analyte sensor. The method of claim 3 , wherein the intermediary device comprises a mobile computing device.

6. The method of claim 3, further comprising the step of pairing the second analyte sensor (110) with the intermediate device to facilitate transmission of the sensor configuration data from the intermediate device to the second analyte sensor (110).

7. The method according to claim 1, further comprising: responsive to determining that the received sensor configuration data can be used to calibrate the second analyte sensor, calibrating the second analyte sensor using at least some of the received sensor configuration data during operation of the second analyte sensor in the initialization mode; and After the calibration, operation of the second analyte sensor is transitioned from the initialization mode to a second measurement mode during which the second analyte sensor generates a second sensor signal indicative of the analyte level of the user.

8. An analyte sensor device comprising: shell; an electronic assembly within the housing; and a sensor element extending from the housing and electrically coupled to the electronics assembly, wherein when the analyte sensor device is deployed on a user, the sensor element provides a sensor signal indicative of an analyte level of the user; The electronic assembly includes at least one processor device and a non-transitory processor-readable medium operatively associated with the at least one processor device, the processor-readable medium including executable instructions configurable to cause the at least one processor device to perform a method comprising the following steps: activating an initialization mode of the analyte sensor device; receiving, during operation of the analyte sensor device in the initialization mode, sensor configuration data for processing by the electronics assembly, the sensor configuration data originating from a second analyte sensor device deployed at or previously deployed at the user; determining whether the received sensor configuration data is suitable for use in calibrating the analyte sensor device; as well as In response to determining that the received sensor configuration data is not suitable for calibrating the analyte sensor device, causing generation of a message prompting the user to obtain an analyte sample.

9. The analyte sensor device of claim 8, wherein: activating the initialization mode of the analyte sensor assembly when the second analyte sensor assembly is deployed at the user and when the second analyte sensor assembly is operating in a second measurement mode, during which the second analyte sensor assembly generates a second sensor signal indicative of the analyte level of the user; and Operation of the analyte sensor assembly in the initialization mode occurs concurrently with operation of the second analyte sensor assembly in the second measurement mode.

10. The analyte sensor device of claim 8, wherein the analyte sensor device receives the sensor configuration data directly from the second analyte sensor device or indirectly from an intermediate device in communication with the analyte sensor device.

11. The analyte sensor device of claim 8, further comprising: in response to determining that the received sensor configuration data can be used to calibrate the analyte sensor device, configuring at least one sensor parameter of the analyte sensor device based on the received sensor configuration data during operation of the analyte sensor device in the initialization mode; and Following the configuring, operation of the analyte sensor device is transitioned from the initialization mode to a measurement mode during which the analyte sensor device generates a sensor signal indicative of the analyte level of the user.

12. The analyte sensor device of claim 11, wherein the configuring comprises calibrating the analyte sensor device using at least some of the received sensor configuration data.

13. A method for automatically initializing an analyte sensor for a user, the method comprising the steps of: activating a new analyte sensor to measure an analyte level of the user; receiving, at the new analyte sensor, sensor configuration data during operation of the new analyte sensor in the initialization mode, the sensor configuration data originating from an old analyte sensor deployed at or previously deployed at the user; determining whether the received sensor configuration data is suitable for calibrating the new analyte sensor; as well as In response to determining that the received sensor configuration data is not suitable for calibrating the new analyte sensor, causing generation of a message prompting the user to obtain an analyte sample.

14. The method of claim 13, wherein activating the new analyte sensor is performed while the old analyte sensor is deployed at the user and operating in a second measurement mode, during which the old analyte sensor generates a second sensor signal indicative of the analyte level of the user.

15. The method of claim 14, wherein operation of the new analyte sensor in the initialization mode is performed concurrently with operation of the old analyte sensor in the second measurement mode.

16. The method of claim 14, wherein the new analyte sensor receives the sensor configuration data directly from the old analyte sensor.

17. The method of claim 13, wherein the new analyte sensor receives the sensor configuration data from an intermediate device in communication with the new analyte sensor.

18. The method of claim 17, wherein the intermediary device comprises a mobile computing device.

19. The method of claim 17, further comprising the step of pairing the new analyte sensor with the intermediate device to facilitate transfer of the sensor configuration data from the intermediate device to the new analyte sensor.

20. The method of claim 13, wherein: determining, by the new analyte sensor based on a sensor glucose value determined by the old analyte sensor and a sensor signal determined by the new analyte sensor, whether the received sensor configuration data can be used to calibrate the new analyte sensor; in response to determining that the received sensor configuration data can be used to calibrate the new analyte sensor, configuring at least one sensor parameter of the new analyte sensor based on the received sensor configuration data during operation of the new analyte sensor in the initialization mode; as well as Following the configuring, operation of the new analyte sensor is transitioned from the initialization mode to a first measurement mode during which the new analyte sensor generates a first sensor signal indicative of the analyte level of the user.

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