Methods and apparatus configured to transmit data in a continuous analyte monitor

Abstract

In one or more embodiments, a base unit of a wearable device for continuous analyte monitoring can include a sensor memory circuit and a sensor assembly. The sensor memory circuit stores information (data) of at least one component of the base unit, e.g., at least one parameter of the sensor assembly. The base unit is configured to couple to a transmitter unit of the wearable device and to communicate the information to the transmitter unit. An analyte assay is conducted based at least in part on the information. Numerous other embodiments are provided.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 033,825, filed June 2, 2020, the disclosure of which is incorporated herein by reference in its entirety for all purposes. Technical Field

[0003] Embodiments of this disclosure relate to methods and apparatus for continuous analyte monitoring. Background Technology

[0004] Continuous analyte monitoring in in vivo samples, such as continuous glucose monitoring (CGM), has become a routine procedure, especially in diabetes care. By providing real-time glucose concentrations, treatment can be applied more promptly, and glycemic status can be better controlled.

[0005] During a CGM procedure, the biosensors of the CGM device are typically inserted subcutaneously and operate continuously in an environment surrounded by tissue and tissue fluid. The biosensors inserted under the skin provide signals to the wireless CGM transmitter of the CGM device, indicating the user's blood glucose levels. These measurements can be taken automatically multiple times throughout the day (e.g., every few minutes or at some other predetermined interval).

[0006] A wireless CGM transmitter can adhere to the outer surface of a user's skin, such as on the abdomen or the back of the upper arm, while a biosensor is inserted through the skin to contact tissue fluid. The biosensor interacts with the tissue fluid, generating an electrical signal proportional to the amount of glucose present. These electrical signals are transmitted to the CGM transmitter for glucose level determination.

[0007] Manufacturing CGM components and biosensors that are both comfortable and cost-effective for patients remains a challenge. Therefore, improvements in CGM devices and methods are desired. Summary of the Invention

[0008] In some embodiments, a base unit for use in a wearable device during continuous analyte monitoring is provided. The base unit includes: a sensor assembly including at least one biosensor configured to be located subcutaneously; and sensor memory circuitry configured to store information (data) relating to at least one parameter of at least one component of the base unit, wherein the base unit is configured to be coupled to a transmitter unit of the wearable device, and wherein the information is transferable to the transmitter unit.

[0009] In some embodiments, a transmitter unit for use in a wearable device during continuous analyte monitoring is provided. The transmitter unit includes electronic components configured to receive information (data) stored in a sensor memory circuit of the base unit of the wearable device in response to the transmitter unit and the base unit being coupled together, wherein the information includes at least one parameter of at least one component of the base unit.

[0010] In some embodiments, a wearable device is provided for use during continuous analyte monitoring. The wearable device includes: a base unit; a sensor assembly located in the base unit and configured to measure an analyte in a tissue fluid; a sensor memory circuit located in the base unit and configured to store information (data) of one or more parameters of one or more components in the base unit; and a transmitter unit configured to be physically coupled to the base unit, wherein the information is transferable from the sensor memory circuit when the base unit and the transmitter unit are coupled together.

[0011] In some embodiments, a method is provided for manufacturing a base unit of a continuous analyte monitor. The method includes: assembling a sensor assembly onto a substrate; assembling a sensor memory circuit onto the substrate; determining one or more parameters of one or more components of the base unit; and storing information (data) of the one or more parameters in the sensor memory circuit.

[0012] In some embodiments, a method for monitoring an analyte is provided. The method includes: inserting a biosensor extending from a base unit of a wearable device into subcutaneous tissue fluid; connecting the base unit and a transmitter unit of the wearable device together; transmitting information stored in a sensor memory circuit in the base unit to the transmitter unit, the information including at least one parameter of at least one component of the base unit; measuring a current passing through the biosensor; and determining an analyte concentration based at least in part on the current and the information.

[0013] Other features, aspects, and advantages of embodiments according to this disclosure will become more fully apparent from the following detailed description, the claims, and the accompanying drawings illustrating several exemplary embodiments. Various embodiments according to this disclosure may also be capable of other and different applications, and several details thereof may be modified in various aspects without departing from the scope of the claims and their equivalents. Therefore, the drawings and description are to be regarded as illustrative in nature and not restrictive. Attached Figure Description

[0014] The accompanying drawings described below are for illustrative purposes and are not necessarily drawn to scale. The drawings are not intended to limit the scope of the invention in any way. Therefore, the drawings are to be considered illustrative in nature and not restrictive.

[0015] Figure 1A A side elevation view of a wearable device, including a transmitter unit and a base unit, configured for use during continuous analyte monitoring according to embodiments provided herein, is shown.

[0016] Figure 1B One or more embodiments provided herein are illustrated. Figure 1A A top-down view of the wearable device.

[0017] Figure 1C The illustration shows a base unit and a transmitter unit according to one or more embodiments provided herein. Figure 1A A cross-sectional side elevation view of a wearable device.

[0018] Figure 1D One or more embodiments provided herein are illustrated. Figure 1C An exploded side view of the cross-section of a wearable device, in which the transmitter unit is separated from the base unit.

[0019] Figure 2A An exploded perspective view of the base unit of a wearable device according to one or more embodiments provided herein is shown.

[0020] Figure 2B An embodiment according to the present document is shown. Figure 2A An exploded perspective view of the sensor memory circuitry, conductors, and printed circuit board of a wearable device.

[0021] Figure 3 The illustrations show one or more embodiments provided herein. Figure 1C A schematic diagram of the circuitry of a wearable device and the connections between them.

[0022] Figure 4A A schematic diagram is shown illustrating an analyte monitoring system including a wearable device and an external device according to one or more embodiments provided herein.

[0023] Figure 4B A schematic diagram is shown illustrating another analyte monitoring system including a wearable device and an external device, according to one or more embodiments provided herein.

[0024] Figure 5 This is a flowchart of a method for manufacturing a base unit of a wearable device for a continuous analyte monitoring system according to one or more embodiments provided herein.

[0025] Figure 6 This is a flowchart of a method for continuous analyte monitoring using a wearable device including a base unit and a transmitter unit, according to one or more embodiments provided herein.

[0026] Figure 7 This is a flowchart of a method for manufacturing a base unit of a persistent analyte monitor according to one or more embodiments provided herein.

[0027] Figure 8 This is a flowchart of a method for subcutaneous monitoring analytes according to one or more embodiments provided herein. Detailed Implementation

[0028] To more closely monitor an individual's analyte levels (e.g., glucose concentration) and detect changes in analyte levels, methods and devices have been developed for continuous analyte monitoring (e.g., continuous glucose monitoring (CGM)). While CGM systems generate glucose signals "continuously" during operation, such as continuous electrochemical signals, measurements of the generated analyte (e.g., glucose) signal are typically performed every few minutes, rather than truly continuously. The description below relates to continuous glucose monitoring; however, the devices and methods described below can be readily adapted to monitor other analytes, such as lactate, in other continuous analyte monitoring systems.

[0029] CGM systems typically have a wearable component (“wearable device”) worn on the body and capable of communicating wirelessly with an external device, such as a handheld receiver or another portable device, like a smartphone with a suitable application software program (app). The wearable device can be worn for days or even weeks (e.g., 1-2 weeks) before being removed and replaced. The wearable device includes a subcutaneously inserted (implanted) biosensor. The wearable device may also include analog circuitry coupled to and configured to bias the biosensor and measure the current signal generated by the implanted biosensor. The wearable device may also include processing circuitry for determining the analyte (e.g., glucose) level based on the measured current signal, and electron transmitter circuitry for transmitting the analyte (e.g., glucose) level to an external receiving device. The wearable device may be attached (e.g., adhered) to an external surface of the skin, such as the abdomen, the back of the upper arm, or other suitable locations. CGM systems measure the concentration of an analyte (e.g., glucose level) in tissue fluid or indirect capillary blood samples.

[0030] CGM systems can provide frequent measurements of a user's analyte (e.g., glucose) levels without requiring the extraction of a blood sample, for example, via finger prick. CGM systems can still occasionally employ finger prick and utilize blood glucose (BGM) measurement systems (e.g., Contour NEXT manufactured by Ascensia Diabetes Care AG in Basel, Switzerland). To initiate the calibration of the CGM system.

[0031] As described above, wearable devices for CGM systems are typically worn for up to two weeks before being removed and replaced with new ones. The need to replace CGM system wearable devices every few weeks significantly increases the cost of performing such continuous analyte monitoring. For example, according to various aspects of this disclosure, biosensors may need to be replaced, but other components can be reused.

[0032] The embodiments provided herein offer a wearable device for use during continuous analyte (e.g., glucose) monitoring. The wearable device described herein includes a base unit (e.g., a disposable portion) and a transmitter unit (e.g., a reusable portion). The base unit may include: a sensor assembly comprising a biosensor configured to monitor a specific analyte; and sensor memory circuitry electronically storing information (data) associated with and / or unique to each individual base unit (e.g., its biosensor assembly). For example, the sensor memory circuitry may store at least one parameter of at least one component of the base unit. For example, the sensor memory circuitry may include PROM, EEPROM, SRAM, SDRAM, and NOR and NAND flash memory. Other types of sensor memory circuitry may be used.

[0033] Specifically, the sensor memory circuitry may include rad-hardened memory, meaning that the sensor memory circuitry (and specifically, rad-hardened memory) will retain information (data) and function normally even after exposure to a dose of radiation (e.g., ionizing radiation (e.g., gamma (γ) radiation) and / or electron beam (E-beam) radiation high enough to sterilize the pedestal unit). In some embodiments, the sensor memory circuitry may be housed in rad-hardened packaging. In some embodiments, the rad-hardened packaging or rad-hardened memory reduces the total ionizing dose (TID) received by the sensor memory circuitry relative to the TID environment outside the sensor memory circuitry. In some embodiments, the reduction in TID received by the sensor memory circuitry may be several orders of magnitude. Radiation-hardened sensor memory circuitry and / or rad-hardened packaging enable the sensor memory circuitry and / or pedestal unit to be sterilized by exposure to radiation without erasing or otherwise damaging the sensor memory of the sensor memory circuitry. Therefore, the complete pedestal unit can be placed in a container for shipment to the user. The pedestal unit is then sterilized using radiation without erasing or otherwise damaging the sensor memory circuitry.

[0034] The transmitter unit may include electronic circuitry for, for example, providing a bias to a sensor assembly, measuring a current signal passing through the sensor assembly (or its associated biosensor), calculating an analyte concentration value (e.g., a glucose concentration value) based on the measured current signal, and transmitting the analyte concentration value and / or related information to an external device, such as an external receiver device or an external transceiver device. In some embodiments, raw readings and / or data generated by the biosensor may be transmitted, and the analyte concentration value may then be calculated by the external device.

[0035] Example circuitry within the transmitter unit may include an analog front-end configured to bias a sensor assembly and sense the current passing through the sensor assembly in appropriate time increments. The circuitry may include operational amplifiers, current sources, current sensing circuitry, comparators, etc. Other circuitry and components within the transmitter unit may include: processing circuitry, such as an analog-to-digital converter for digitizing the current signal; a memory for storing the digitized current signal; a controller configured to calculate the analyte concentration level based on the measured current signal, such as a microprocessor, microcontroller, etc.; and transmitter circuitry for transmitting the analyte concentration level to an external device.

[0036] The transmitter unit may also include circuitry and / or components that enable the sensor memory circuitry in the base unit to transfer information (e.g., data) stored therein, and circuitry and / or components that receive such information. This information may be data stored and transmitted using data storage and transmission technologies. For example, when the transmitter unit and the base unit are physically connected, they may become electrically connected. This electrical connection allows information stored in the sensor memory circuitry to be transferred to the transmitter unit. This information can be used by the circuitry in the transmitter unit and / or an external receiver device to calculate analyte concentrations and for other functions, such as data display (e.g., display of analyte concentration values ​​and / or trends).

[0037] Electronic circuitry is typically the most expensive part of a wearable device and, if designed, can last for a significantly longer period than the wearable device is used. The base unit includes components that penetrate the skin and require frequent replacement, such as biosensors. For example, wearable devices are typically discarded after about two weeks, while the circuitry within the transmitter unit can, in some cases, persist indefinitely. In some embodiments, reusable transmitter units can be used with two or more, three or more, four or more, five or more, ten or more, twenty or more, thirty or more, forty or more, fifty or more, or even one hundred or more base unit replacements.

[0038] In some embodiments, a wearable device for use during continuous analyte monitoring may include a base unit (e.g., a disposable base unit) containing at least sensor components and sensor memory circuitry. The wearable device may also include a reusable transmitter unit configured to engage with the base unit and receive information stored in the sensor memory circuitry of the base unit. In some embodiments, the base unit may be configured to be discarded after a single analyte monitoring cycle (e.g., 10-14 days), and the transmitter unit may be configured to detach from the base unit after a single analyte monitoring cycle and reuse (e.g., reattach) it to another new base unit. These and other embodiments, as well as methods for manufacturing and / or using such wearable devices, are referenced below. Figure 1A-8 Describe it.

[0039] Now for reference Figure 1A-1DThese figures illustrate various views of a wearable device 100 (e.g., a continuous analyte monitor) for use during continuous analyte monitoring (e.g., continuous glucose monitoring) according to one or more embodiments provided herein. The wearable device 100 is shown as at least partially dome-shaped in at least a portion thereof. The wearable device 100 is not limited to the dome shape shown herein and may have other shapes. The base unit 102 and the transmitter unit 104 may be any suitable shape (e.g., circular, elliptical, square, rectangular, etc.) in a top plan view. For example, the wearable device 100 may have a predominantly rectangular shape, and its size and shape may be set to resemble a medical bandage. In such embodiments, the base unit 102 may be rectangular in a plan view.

[0040] The base unit 102 may be a disposable unit, and the transmitter unit 104 may be a reusable unit, wherein the transmitter unit 104 and the base unit 102 are configured to be coupled together. In some embodiments, the base unit 102 and the transmitter unit 104 are also configured to be separable from each other. For example, the transmitter unit 104 and the base unit 102 may be physically coupled together to form a wearable device 100, such as... Figure 1A and 1B As shown in the diagram. Any suitable mechanical mechanism configured to allow the transmitter unit 104 to be coupled to the base unit 102 can be used. When physically coupled, the transmitter unit 104 and the base unit 102 can also be electrically coupled together, such that data signals and / or current can be transmitted and transferred between electrical components in the transmitter unit 104 and electrical components in the base unit 102. In some embodiments, this transmission may occur in response to the physical coupling of the transmitter unit 104 and the base unit 102. In other embodiments, the transmission may be initiated by a command such as a start command.

[0041] As described below, both transmitter unit 104 and base unit 102 can be hermetically sealed units (e.g., waterproof), where only the electrical contacts of transmitter unit 104 and base unit 102 are exposed. Once transmitter unit 104 and base unit 102 are physically joined together, the electrical contacts can also be sealed from the external environment, for example, by using a sealing member.

[0042] A biosensor 108 (e.g., inserted through a portion of the user's skin 118) may extend from the base unit 102 and may be configured to be at least partially located in tissue fluid in the subcutaneous region as described herein. The biosensor 108 may be or may include, for example, an analyte sensor or analyte sensor portion at or near a tip 108T. The biosensor 108 may be inserted using an insertion device (not shown) with a sharp tip that penetrates the skin to introduce the biosensor 108 into the user's subcutaneous region. Any suitable insertion device may be used. Sensor circuitry coupled to the biosensor 108 may include a device that applies at least one bias voltage to the analyte sensor portion of the biosensor 108 within the tissue fluid, wherein other devices measure the resulting current, which is proportional to the monitored analyte.

[0043] In some embodiments, the base unit 102 is configured to be discarded after a single analyte monitoring cycle (e.g., 7 days, 10 days, 14 days, or some other suitable time period). In some embodiments, the transmitter unit 104 may be configured to be removed (detached) from the base unit 102 after a single analyte monitoring cycle and reused with another new base unit.

[0044] like Figure 1C and 1D As shown, the base unit 102 may include a substrate 110 having a sensor assembly support location 112 and a memory circuit location 114. The substrate 110 may have a first surface 110A and an opposing second surface 110B. The first surface 110A may be configured to be adjacent to or near a corresponding surface 116A of the transmitter unit 104. The second surface 110B may be configured to be adjacent to the user's skin surface 118S. Figure 1A Positioned and / or interconnected to the skin surface. The first surface 110A may include a recessed portion 110C, such as a groove, configured to receive a gasket 120, such as an O-ring. For example, the recessed portion 110C may be a peripheral groove, etc., receiving the gasket 120 to seal the periphery between the transmitter unit 104 and the base unit 102. In some embodiments, the substrate 110 may be formed of a plastic, such as, but not limited to, acrylonitrile-butadiene-styrene (ABS), polycarbonate, nylon, acetal, polyphthalamide (PPA), polysulfone, polyethersulfone, polyetheretherketone (PEEK), polypropylene, high-density polyethylene (HDPE), and low-density polyethylene (LDPE). Other suitable materials may be used in the substrate 110.

[0045] An adhesive layer 122 (e.g., double-sided tape or pressure-sensitive adhesive) may be attached (e.g., adhered) to a second surface 110B of the substrate 110, and may adhere the base unit 102 to a user's skin surface 118S. The adhesive layer 122 may include a first side 122A and a second side 122B positioned opposite to the first side 122A. The first side 122A may adhere to the second surface 110B of the substrate 110. The second side 122B of the adhesive layer 122 may be configured to adhere to the user's skin surface 118S in order to adhere the base unit 102 to the skin surface 118S.

[0046] For further reference Figure 2A The diagram shows an exploded isometric view of an embodiment of the base unit 102. A sensor assembly support location 112 can provide a support location for a sensor assembly 126 used to measure or sense an analyte in subcutaneous tissue, such as tissue fluid, belonging to a user. For example, the sensor assembly 126 can be configured to measure an analyte (e.g., glucose) in subcutaneous tissue. The sensor assembly support location 112 can be any suitable shape (e.g., rectangular, square, circular, etc.) that supports and / or holds the sensor assembly 126 within or to the base unit 102. The sensor assembly 126 can be electrically and physically coupled to the biosensor 108. In some embodiments, the sensor assembly 126 can be integrally formed with the biosensor 108. The sensor assembly 126 can facilitate the conduction of electrical signals to and from the tip 108T and / or other portions of the biosensor 108.

[0047] The biosensor 108 may include an active region comprising one or more catalysts and / or reagents configured to sense the presence and concentration level of a specific analyte (e.g., glucose). The substrate 110 may include a hole 130 through which the biosensor 108 can pass. A gasket 132 (e.g., an O-ring – see also...) Figure 1C and 1D The gasket 132 may be located at least partially within the aperture 130 and may prevent contaminants from passing through the aperture 130 after the biosensor 108 is inserted. For example, the gasket 132 may form a seal between the biosensor 108 and the aperture 130 to prevent contaminants (e.g., blood) from entering the base unit 102. The gasket 132 may also prevent other contaminants from contacting the user's skin surface 118S.

[0048] Sensor assembly 126 may include a plurality of conductive contact pads 134 that electrically connect sensor assembly 126 to other components and ultimately to transmitter unit 104. In the embodiments described herein, sensor assembly 126 includes four contact pads 134. In other embodiments, sensor assembly 126 may include more or fewer contact pads 134.

[0049] Connector 136 can be electrically coupled to (e.g., contact) contact pad 134, and contact pad 134 can be electrically coupled to sensor pad 140A of transmitter unit 104. In some embodiments, connector 136 can be a resilient connector, which may be referred to as a zebra stripe. In some embodiments, connector 136 can be a dot connector or a dot resilient connector. In some embodiments, connector 136 can be coupled only in the z-direction, for example, along the z-axis ( Figure 1D (Conduction). Therefore, connector 136 can be a single device that can be positioned above all contact pads 134 and conduct current only to the location directly above the contact pads 134. In such embodiments, when transmitter unit 104 and base unit 102 are physically coupled together, connector 136 can electrically connect contact pads 134 to sensor pads 140A of transmitter unit 104.

[0050] The base unit 102 includes a sensor memory circuit 142 that can be packaged as a memory device. In some embodiments, the memory circuit and / or memory device may be a single memory component. The sensor memory circuit 142 may be secured within a memory circuit location 114 by an adhesive 145 such as double-sided tape or epoxy adhesive. Other securing configurations may be used to secure the sensor memory circuit 142 within the memory circuit location 114 or to another location within the base unit 102. The sensor memory circuit 142 may include radiation-hardened memory (radiation-resistant memory) or may be located within a radiation-resistant package. The radiation-resistant memory includes a package and / or circuitry that retains information (e.g., data) stored therein when the package and / or circuitry is exposed to radiation used for sterilizing the base unit 102. The sensor memory circuit 142 may include a programmable read-only memory (PROM), an electrically erasable programmable read-only memory (EEPROM), a static random access memory (SRAM), a synchronous dynamic random access memory (SDRAM), and / or NOR and NAND flash memory. Other types of sensor memory circuits can be used in sensor memory circuit 142.

[0051] During the manufacture of the base unit 102 and / or the wearable device 100, radiation, such as ionizing radiation, gamma (z) radiation, and / or electron beam (E-beam) radiation, may be used to sterilize the base unit 102 and / or the wearable device 100. In some embodiments, the base unit 102 is manufactured separately from the transmitter unit 104, so only radiation is used to sterilize the base unit 102. In some embodiments, radiation may not be used to sterilize the transmitter unit 104. For example, the base unit 102 may be exposed to radiation to sterilize all its components.

[0052] Conventional memory devices and other electronic components may be damaged by radiation used during sterilization. For example, components within a conventional memory device may be damaged by radiation, or the conventional memory may be erased by radiation. The sensor memory circuit 142 may be radiation-resistant and / or packaged in radiation-resistant packaging. The radiation-resistant sensor memory circuit 142 or the sensor memory circuit packaged in radiation-resistant packaging provides that the sensor memory circuit 142 can be exposed to total ionizing dose (TID) radiation used for sterilization without erasing the information (data) stored therein.

[0053] In some embodiments, radiation-hardened (radiation-resistant) packaging or radiation-resistant memory reduces the total ionizing dose (TID) received by the sensor memory circuitry 142 within the packaging relative to the external ionizing dose environment. In some embodiments, the reduction in TID is several orders of magnitude. The radiation-resistant sensor memory circuitry 142 enables the sensor memory circuitry 142 and the base unit 102 to be sterilized by radiation without erasing and / or damaging the sensor memory circuitry 142. For example, the base unit 102 may be assembled together with the sensor memory circuitry 142 fixed therein. The base unit 102, in which the sensor memory circuitry 142 is fixed, can then be sterilized by radiation.

[0054] In some embodiments, the sensor memory circuit 142 may have a single-wire interface that utilizes a voltage-based digital system operating using only two contacts—data and ground—for half-duplex bidirectional communication. Reference Figure 2BThis image shows an exploded view of an embodiment of sensor memory circuitry 142 and a portion of alternative connector 136A. Embodiments of sensor memory circuitry 142 have two contacts (e.g., two external nodes): a data contact pad 144A (e.g., a data node) and a ground contact pad 144B (e.g., a ground node). In some embodiments, these two contacts are the only contact pads or external nodes of sensor memory circuitry 142. Single-wire type sensor memory circuitry 142 can be implemented for use in transient contact environments. For example, disconnecting the voltage of sensor memory circuitry 142 or a voltage drop in the power supply places sensor memory circuitry 142 into a defined reset state. When the voltage returns to sensor memory circuitry 142, sensor memory circuitry 142 wakes up and can signal its presence. As described below, sensor memory circuitry 142 can then transmit information stored therein to, for example, transmitter unit 104. Other types of memory circuitry can be used in sensor memory circuitry 142. For example, sensor memory circuitry 142 may include an integrated circuit (I2C) or serial peripheral interface (SPI) architecture.

[0055] Connector 136A can be used in place of connector 136. Connector 136A can be a resilient connector, such as a z-connector, which has repeating layers of conductor and insulator. Therefore, connector 136A conducts in the z-direction as described above.

[0056] Each sensor memory circuit can store sensor information specific to an individual base unit and / or a component therein. For example, each sensor memory circuit can store at least one parameter of at least one component of the base unit in which it resides. Therefore, sensor memory circuit 142 can store information specific to base unit 102 and / or at least one component therein. The sensor information may include one or more parameters, including:

[0057] a. Electrode sensitivity slope

[0058] b. Production date

[0059] c. Batch or lot number

[0060] d. Security Code

[0061] e.EEPROM version

[0062] f. Serial number

[0063] Sensitivity information may include the sensitivity slope of the electrodes of biosensor 108 and / or sensor assembly 126. In embodiments where base unit 102 includes more than one biosensor, sensitivity information may include data, such as the sensitivity slope of each biosensor.

[0064] Sensitivity information may include, for example, one or more mathematical functions or coefficients that can be obtained by testing sensor assembly 126. Each biosensor and / or sensor assembly may be unique with respect to at least their respective sensitivity; therefore, this information may include unique parameters relating to biosensor 108 and / or sensor assembly 126 located in the same pedestal unit 102. Transmitter unit 104 or other components that process data generated by sensor assembly 126 may use the sensitivity information or parameters relating to other components to correctly calculate and determine analyte levels.

[0065] In some embodiments, one or more parameters (e.g., sensor information) may include the manufacturing date of one or more components in the base unit 102. For example, sensor information may include the manufacturing date of sensor assembly 126, biosensor 108, and / or sensor memory circuitry 142. Sensor information can be used to determine whether components within the base unit 102 have expired. For example, some components within the base unit 102 may have a limited shelf life. If an attempt is made to use the base unit 102, and the base unit has one or more components whose shelf life has expired, an indication can be provided to the user. In some embodiments, if the base unit 102 includes more than one biosensor, the sensor information may include the manufacturing date of biosensor 108 or multiple biosensors. An apparatus for analyzing analyte levels determined by biosensor 108 can provide an indication of whether the service life of biosensor 108 exceeds a predetermined service life.

[0066] In some embodiments, sensor information may include at least one unique identifier of one or more components of base unit 102, which can distinguish (e.g., identify) base unit 102 and / or its components from other base units. For example, at least one unique identifier may be a serial number and / or batch number. In some embodiments, the unique identifier may include the serial number and / or batch number of base unit 102, sensor assembly 126, sensor memory circuitry 142, and / or one or more other components of base unit 102. For example, an apparatus for analyzing analyte levels may use one or more unique identifiers to determine whether any component has been recalled or identified as potentially defective. The apparatus may also perform analyte calculations or determinations based on the actual components and / or base unit 102 in base unit 102 as determined by its unique identifier.

[0067] In some embodiments, sensor information may include one or more model numbers or other identifiers of components within the base unit 102 or the identifier of the base unit 102. In some embodiments, sensor information may include model numbers of the sensor memory circuitry 142, sensor assembly 126, base unit 102, and / or other components of the base unit 102. Model numbers and / or generic identifiers may be used when processing data generated by the base unit 102. For example, a particular model of biosensor 108 may have parameters different from another model of biosensor.

[0068] In some embodiments, sensor information may include one or more security codes for accessing components of the base unit 102 or transmitter unit 104. For example, transmitter unit 104 or another component that processes data generated by base unit 102 may require security codes stored in sensor memory circuitry 142 to allow communication with it. The use of security codes can prevent illegally manufactured or unauthorized base units from communicating with transmitter unit 104 or other devices. Thus, security codes can prevent wearable device 100 from reporting potentially erroneous analyte levels due to the use of an incorrect base unit, or otherwise enhance security.

[0069] During the manufacture and / or assembly of the base unit 102, the sensor assembly 126 may be placed in the sensor assembly support location 112, and the sensor memory circuit 142 may be placed in the memory circuit location 114. The sensor information described above may be programmed into the sensor memory circuit 142 before or after it is placed within the base unit 102, as further described below.

[0070] In some embodiments, connector 136 may include one or more electrodes 214 that can be electrically connected to at least some components within base unit 102 and transmitter unit 104. Figure 1A-1D Electrode 214 can be moved axially (in the Z direction) within the body of connector 136 and can be biased relative to connector 136 to make electrical contact with components (e.g., contact pads) within base unit 102 and / or transmitter unit 104. In some embodiments, the number of electrodes 214 may be equal to the number of contact pads on the components within base unit 102 and / or transmitter unit 104. Figure 2A and 2B In one example, sensor assembly 126 may include four contact pads 134, and sensor memory circuit 142 may include two contact pads 144, namely data contact pad 144A and ground contact pad 144B (e.g., node), so connector 136 includes six electrodes 214 formed therein.

[0071] One or more of the electrodes 214 may be located in planes that can group the electrodes according to electrical components that are configured to contact and allow the electrodes to be biased together. For example, four sensor electrodes 214A may be configured to electrically contact the plate-shaped sensor pad 140A on the transmitter unit 104, and the four sensor electrodes 214A may also contact the four contact pads 134 of the sensor assembly 126. Similarly, the two memory electrodes 214B of the connector 136 may be configured to contact the two contact pads 144 of the sensor memory circuit 142 and the memory pad 140B of the transmitter unit 104.

[0072] Therefore, the contact pad 140 includes a sensor pad 140A, which, when the transmitter unit 104 and the base unit are physically connected, i.e., via (e.g.) Figure 1D The sensor electrode 214A (shown downwards) is biased to contact the contact pad 134, and is electrically connected to the sensor assembly 126 by means of the sensor electrode 214A. Similarly, the contact pad 140 may include a memory pad 140B, which is connected between the transmitter unit 104 and the base unit 102 via (e.g.) Figure 1D When the downward biased sensor electrode 214A is physically connected to the contact pad 144, it is electrically connected to the sensor memory circuit 142 by means of the memory electrode 214B. The sensor pad 140A may be electrically connected to one or more components within the transmitter unit 104 that receive and / or process data from the sensor assembly 126 and / or transmit signals including bias voltage and current to the sensor assembly 126. The memory pad 140B may be electrically connected to one or more components within the transmitter unit 104 that transmit signals to and / or receive signals from the sensor memory circuit 142.

[0073] Figure 2A Embodiments of connector 136 may include sensor board 216A and memory board 216B. Sensor board 216A may include sensor electrode 214A, and memory board 216B may include memory electrode 214B. Connector 136 may include other boards and / or other electrodes.

[0074] Wearable device 100 ( Figure 1A-1D ) may include power supply ( Figure 1A-2B (not shown in the image), for example, a battery (312– Figure 3 and Figures 4A-4BThe power source is configured to provide power to components of the wearable device 100. In some embodiments, the power source may be a battery, storage capacitor, solar cell, generator, etc. In some embodiments, the power source may provide power to the sensor memory circuitry 142 when the transmitter unit 104 and the base unit 102 are physically coupled together. In some embodiments, the power source may be located in the base unit 102, and in other embodiments, the power source may be located in the transmitter unit 104. In some embodiments, at least one of the sensor assembly 126 and the sensor memory circuitry 142 is configured to receive power in response to the coupling of the transmitter unit 104 and the base unit 102. In embodiments where the power source has a long lifespan, the power source may be located in the transmitter unit 104. In embodiments where the power source has a short lifespan, the power source may be located in the base unit 102, since the base unit 102 also has a short lifespan and both can subsequently be replaced simultaneously. In some embodiments, the transmitter unit 104 and the base unit 102 may each have their own power source.

[0075] The transmitter unit 104 may include one or more electronic components that communicate with one or more electronic components within the base unit 102 and with one or more external devices. (See again) Figure 1A-1D The transmitter unit 104 may include an encapsulation layer 116 (e.g., a top cover) configured to be positioned against or above the base unit 102. The encapsulation layer 116 may include an opening 150 configured to receive at least a portion of the base unit 102. The encapsulation layer 116 may encapsulate electronics and other components within the transmitter unit 104 to prevent exposure to contaminants. In some embodiments, the encapsulation layer 116 may be a pre-molded base in which a substrate 152 is positioned prior to the formation of the encapsulation layer 116 (e.g., by a molding process).

[0076] As described below, substrate 152 can support components located within or on transmitter unit 104, such as electrical components and contact pads 140. In some embodiments, substrate 152 can be a printed circuit board, such as a flexible printed circuit board, and can be used to support electronic components, such as analog front-end circuitry and transmitter modules as described herein. Substrate 152 can be made of materials such as copper, polyimide, polyester (PET), polyethylene naphthalate (PEN), polyimide, glass fiber, and acrylic adhesives. Substrate 152 can be made of other materials.

[0077] In some embodiments, the encapsulation layer 116 may be formed of a single layer or multiple layers. For example, the encapsulation layer 116 may be formed of one or more layers of liquid silicone rubber (LSR), thermoplastic elastomer (TPE), etc. Other materials may be used, such as, but not limited to, ABS, polycarbonate, nylon, acetal, PPA, polysulfone, polyethersulfone, PEEK, polypropylene, HDPE, LDPE, etc. In some embodiments, the encapsulation layer 116 may be formed at a temperature below 100°C, and in some embodiments, it may be formed at a temperature below 80°C.

[0078] exist Figure 1A-1D In some embodiments, substrate 152 may be located in or at least partially accessible via opening 150. Memory pad 140B and sensor pad 140A may be attached to the lower surface 152A of substrate 152 and are accessible via opening 150. One or more electronic components 154 may be physically and / or electrically connected to the upper surface 152B of substrate 152.

[0079] The transmitter unit 104 and the base unit 102 can be configured to be coupled together to complete the wearable device 100. For example, the transmitter unit 104 can be configured to attach to, detach from, insert into, and / or remove from the base unit 102. Various retaining features can be included in the base unit 102 and the transmitter unit 104 for such coupling. Retaining features allow the transmitter unit 104 to be removably attached to the base unit 102, i.e., it can be detachable. (Reference) Figure 2A The base unit 102 may include a first retaining feature 220A and a second retaining feature 220B, which are mechanically connected and / or engaged with corresponding retaining features on the transmitter unit 104. The first retaining feature 220A and the second retaining feature 220B allow the transmitter unit 104 and the base unit 102 to be removably coupled together. Other numbers and types of retaining features and retaining features in other locations may be used. For example, the first retaining feature 220A and the second retaining feature 220B may include protrusions that engage with openings, slots, or other features in the transmitter unit 104. Optionally, magnets, Velcro, surfaces with adhesive, etc., may be used to allow for separation and / or attachment.

[0080] Now for reference Figure 3 The figure illustrates a schematic diagram of an embodiment of the wearable device 100. Figure 3As shown, when the base unit 102 and the transmitter unit 104 are physically connected, electrical signals can be transmitted between the base unit 102 and the transmitter unit 104 via connector 136 (or 136A). For example, contact pads 144 on the sensor memory circuit 142 (e.g., data contact pad 144A and ground contact pad 144B) are electrically connected to memory pad 140B in the transmitter unit 104 via connector 136. Similarly, contact pads 134 on the sensor assembly 126 are electrically connected to sensor pad 140A in the transmitter unit 104. Therefore, when the transmitter unit 104 and the base unit 102 are physically connected, electrical and electronic signals can be transmitted between the transmitter unit 104 and the base unit 102.

[0081] In some embodiments, transmitter unit 104 may include an analog front end 308 configured to drive sensor assembly 126 and / or process sensor data generated by sensor assembly 126, including biosensor 108. Analog front end 308 may be configured to apply a bias voltage to sensor assembly 126 and measure the resulting current through sensor assembly 126. For example, analog front end 308, in conjunction with sensor assembly 126, may apply a bias voltage to biosensor 108 located in tissue fluid and measure the resulting current. As described above, the resulting current is proportional to the analyte concentration. Analog front end 308 may perform other, fewer, and / or more functions.

[0082] Transmitter unit 104 may include a microcontroller 310 coupled to analog front-end 308 and / or other circuitry. Microcontroller 310 may include processing circuitry for processing sensor data generated by sensor assembly 126 and / or analog front-end 308. For example, in some embodiments, microcontroller 310 may convert an analog current signal generated by sensor assembly 126 into a digital current signal, store the current signal, and / or at least partially calculate the analyte concentration level based on the current signal. Microcontroller 310 may also communicate with sensor memory circuitry 142 via input / output (I / O) ports. For example, sensor information may be received via the I / O ports.

[0083] In some embodiments, the microprocessor 310 may include: a processor, such as a microcontroller, microprocessor, etc.; processor memory; an analog-to-digital converter; etc. The processor memory may include computer program code stored therein, which, when executed by the processor, causes the transmitter unit 104 and the wearable device 100 to perform certain functions and / or communicate with one or more external devices, such as an external CGM device or a smartphone that includes and is capable of executing software programs (e.g., applications or apps) to calculate and / or display analyte data.

[0084] In some embodiments, the microcontroller 310 can transmit current signals, analyte concentration information, and / or other information to an external receiver device. In some embodiments, the microcontroller 310 can receive instructions, data, and / or other information from an external device.

[0085] Other circuitry within the microcontroller 310 or transmitter unit 104 may include circuitry configured to be electrically connected to the sensor memory circuitry 142. Figure 3 In some embodiments, the microcontroller 310 may include an input / output (I / O) port electrically connected to a data contact pad 144A of the sensor memory circuit 142 when the base unit 102 and the transmitter unit 104 are coupled together. The microcontroller 310 can receive data stored in the sensor memory circuit 142 via the I / O port, such as the aforementioned sensor information relating to one or more parameters of one or more components of the base unit 102. In some embodiments, a signal (e.g., a pull signal) can be transmitted from the I / O port of the microcontroller 310 to the sensor memory circuit 142, causing the sensor memory circuit 142 to transmit data without user input. Therefore, the sensor memory circuit 142 can automatically transmit data to the microcontroller 310 in response to the coupling of the transmitter unit 104 and the base unit 102. Optionally, the transmission of sensor information to the I / O port can be performed by means of a prompt, for example, from an external device.

[0086] The microcontroller 310 may store information transmitted from the sensor memory circuitry 142 and may use this information when calculating analyte concentrations and / or performing other functions. In other embodiments, this information may be retained in the sensor memory circuitry 142 and may be accessed by the microcontroller 310 or other circuitry as needed during processing. As described above, the information stored in the sensor memory circuitry 142 may include sensor information relating to the sensitivity of the sensor assembly 126 and / or the biosensor 108, which may be used by the microcontroller 310 when calculating analyte concentrations based on measurements taken by at least the sensor assembly 126 and / or the biosensor 108. In some embodiments, at least some of the information may be transmitted to an external device that may use the information to calculate analyte concentrations. In some embodiments, this information may be provided to a user of the wearable device 100. For example, the user may be provided with the manufacturing date and / or expiration date of the base unit 102, which may enable the user to determine whether the base unit 102 should be used. In some embodiments, before communication can be initiated between the transmitter unit 104 and the base unit 102 or between the wearable device 100 and an external device, the user may need to input a security code that matches the security code stored in the sensor memory circuit 142 into the external device.

[0087] The transmitter unit 104 may include a power source, such as a battery 312, to provide power to both the transmitter unit 104 and the base unit 102. In some embodiments, the power source may be located within the base unit 102, and in other embodiments, the base unit 102 and the transmitter unit 104 may each have their own power source. Figure 3 In this embodiment, the battery 312 can be located within the transmitter unit 104, thus the base unit 102 does not require a power source. Therefore, the component and manufacturing costs of the base unit 102 are reduced compared to conventional devices. The battery 312 can provide power to the analog front-end 308 and the microcontroller 310. When included on the transmitter unit 104, the battery can be rechargeable.

[0088] When the transmitter unit 104 and the base unit 102 are coupled together, the battery 312 can provide power to the sensor memory circuitry 142 and the sensor assembly 126, in some embodiments via an analog front-end 308. Examples of batteries 312 include flexible lithium polymer batteries, button batteries such as lithium manganese, silver oxide, and alkaline button batteries (e.g., CR2032, SR516, and LR60 type button batteries). Other power source / battery types can be used.

[0089] Figure 4A A more detailed block diagram of an example of an analyte monitoring system 400 according to embodiments provided herein is shown. Figure 4A In some embodiments, the analog front end 308 may include a bias circuit 444, which may be configured to communicate via connector 136 (shown as a dotted line, but may be as shown in the image). Figure 1C , 1D (Or configured as in 2B) is connected to sensor assembly 126. Bias circuit 444 can be configured to apply a bias voltage, such as a continuous DC bias voltage, to the sensor portion in contact with the analyte fluid via sensor assembly 126 and biosensor 108. In this example embodiment, the analyte fluid may be human tissue fluid, and the bias voltage may be applied, for example, to the electrodes (not shown) of biosensor 108 (e.g., working electrode, reverse electrode, etc.).

[0090] In some embodiments, the biosensor 108 may include at least two electrodes, with a bias voltage applied to both electrodes. In such cases, the resulting current can be measured via the sensor assembly 126. In other embodiments, the biosensor 108 may include three electrodes, such as a working electrode, a counter electrode, and a reference electrode. In such cases, a bias voltage may be applied between the working electrode and the reference electrode, and the resulting current can be measured, for example, via the working electrode.

[0091] In embodiments where the wearable device 100 is a continuous glucose monitor (CGM), the biosensor 108 and / or its electrodes may include reagent chemicals that react with a glucose-containing solution in a reduction-oxidation reaction, affecting the concentration of charge carriers and the time-varying impedance of the biosensor 108. Example chemicals include glucose oxidase, glucose dehydrogenase, etc. In some embodiments, a mediator, such as ferricyanide or ferrocene, may be used. In some embodiments, the biosensor 108 may include one or more microbial sensors, such as a microbial sensor array.

[0092] For example, the bias voltage generated and / or applied by bias circuit 444 can be in the range of about 0.1 to 1 volt relative to the reference electrode. Other bias voltages can be used. In response to the bias voltage, current flows through biosensor 108 located in the analyte-containing body, and the analyte concentration in the analyte-containing body is measured by current measurement circuit 446 (also referred to as current sensing circuit). Current measurement circuit 446 can be configured to sense and / or measure a current measurement signal (I0). MEASThe magnitude of the current measurement signal indicates the magnitude of the current passing through the biosensor 108. In some embodiments, the current measurement circuit 446 may use, for example, a suitable current-to-voltage converter (CVC). In some embodiments, the current measurement circuit 446 may include a resistor having a known nominal value and a known nominal accuracy (e.g., 0.1% to 5%, or even less than 0.1% in some embodiments), through which the current transmitted from the biosensor 108 passes. The voltage generated across the resistor in the current measurement circuit 446 represents the magnitude of the current and can be used as a current measurement signal (I0). MEAS Output.

[0093] In some embodiments, the sampling circuit 448 can be connected to the current measurement circuit 446 and can be configured to sample the current measurement signal I. MEAS Sampling is performed. The sampling circuit 448 can generate a current measurement signal I. MEAS (e.g., a digitized time-domain sample data of an analyte signal, such as glucose). For example, sampling circuitry 448 can be any suitable analog-to-digital converter (ADC) circuit configured to receive a current measurement signal I, which is an analog signal in this embodiment. MEAS The current measurement signal is converted into a digital signal with a desired number of bits as output. In some embodiments, the number of bits output by the sampling circuit 448 may be sixteen bits, but more or fewer bits may be used in other embodiments. In some embodiments, the sampling circuit 448 may sample the current measurement signal I at a sampling rate in the range of approximately 10 samples per second to 1,000 samples per second. MEAS Sampling can be performed. Faster or slower sampling rates can be used. For example, a sampling rate such as approximately 10kHz to 100kHz can be used and downsampled to further reduce the signal-to-noise ratio. Other suitable sampling circuits can be employed.

[0094] The microcontroller 310 may include a processor 450, which may be coupled to the sampling circuit 448 and further coupled to the memory 454. In some embodiments, the processor 450 and the sampling circuit 448 are configured to communicate directly with each other via a wired path (e.g., via a serial or parallel connection). In other embodiments, the connection between the processor 450 and the sampling circuit 448 may be made by means of the memory 454. In this configuration, the sampling circuit 448 writes data to the memory 454, and the processor 450 reads data from the memory 454.

[0095] The memory 454 may already store one or more gain functions 456 for determining analyte levels (e.g., glucose levels) based on the raw signals obtained from the current measurement circuit 446 and / or sampling circuit 448. For example, in some embodiments, three or more gain functions may be stored in the memory 454, each for a different segment (time period) of the collected analyte data. The memory 454 may also store multiple instructions, which may be based, for example, in part on the current measurement signal I. MEAS The sensor information received from the sensor memory circuit 142 is used to calculate the analyte level. In various embodiments, the processor 450 may be a computing resource, such as, but not limited to, a microprocessor, microcontroller, embedded microcontroller, digital signal processor (DSP), or a field-programmable gate array (FPGA) configured to be used as a microcontroller, etc.

[0096] Memory 454 may be a memory, such as, but not limited to, one or more of volatile memory and / or non-volatile memory. Volatile memory may include, but is not limited to, static random access memory (SRAM) or dynamic random access memory (DRAM). Non-volatile memory may include, but is not limited to, electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory (e.g., in a NOR or NAND configuration and / or in a stacked or planar arrangement and / or in a single-cell (SLC), multi-cell (MLC), or combined SLC / MLC arrangement EEPROM type), resistive memory, filamentary memory, metal-oxide memory, phase-change memory (e.g., chalcogenide memory), or magnetic memory. For example, memory 454 may be packaged as a single chip or multiple chips. In some embodiments, memory 454 may be embedded in an integrated circuit along with one or more other circuits, such as in an application-specific integrated circuit (ASIC). In some embodiments, memory 454 may be integrated with processor 450.

[0097] In some embodiments, a plurality of instructions stored in memory 454 may include instructions that, when executed by processor 450, cause processor 450 to perform the following operations: (a) receiving sensor information stored in sensor memory circuitry 142; (b) causing wearable device 100 (via bias circuitry 444, sensor assembly 126, current measurement circuitry 446, and / or sampling circuitry 448) to measure a current signal from biosensor 108; (c) storing the current signal in memory 454; (d) calculating an analyte level (e.g., concentration) based on the stored current signal, gain function 456, and / or sensor information from sensor memory circuitry 142; and (e) transmitting the analyte level to a user. In some embodiments, the analyte level is a glucose level, i.e., a glucose concentration.

[0098] As described above, memory 454 may have a plurality of instructions stored therein, which, when executed by processor 450, cause processor 450 to perform various actions specified by one or more of the stored instructions. Memory 454 may also have portions reserved for one or more "scratchpad" storage areas, which can be used for read or write operations performed by processor 450 in response to the execution of one or more of the instructions.

[0099] exist Figure 4A In some embodiments, the bias circuit 444, sensor assembly 126, current measurement circuit 446, sampling circuit 448, processor 450, and memory 454 may be disposed within the transmitter unit 104 of the wearable device 100. In some embodiments, the transmitter unit 104 may include a local display 460 for displaying information such as analyte and / or glucose concentration information without the use of external devices. The local display 460 may be any suitable type of human-perceptible display, such as, but not limited to, a liquid crystal display (LCD), a light-emitting diode (LED) display, or an organic light-emitting diode (OLED) display.

[0100] Still referencing Figure 4AThe analyte monitoring system 400 may also include an external device 464 (e.g., an external receiver device). A processor 466 and a display 468 may be disposed within the external device 464. The display 468 may be coupled to the processor 466. The processor 466 may control the text or images displayed on the display 468. In some embodiments, at least some of the sensor information stored in the sensor memory circuitry 142 may be transmitted to the external device 464, whereby the sensor information may be processed by the processor 466 and displayed on the display 468. In some embodiments, at least some of the processing for determining the analyte level may be performed by the processor 466 and may be displayed on the display 468. The display 468 may be any suitable type of human-perceptible display, such as, but not limited to, a liquid crystal display (LCD), a light-emitting diode (LED) display, or an organic light-emitting diode (OLED) display.

[0101] External device 464 and transmitter unit 104 can be communicatively connected. In some embodiments, the communicative connection between external device 464 and transmitter unit 104 can be achieved, for example, via wireless communication through transmitter circuitry and / or receiver circuitry (e.g., transmit / receive circuitry 470A in transmitter unit 104 and transmit / receive circuitry 470B in external device 464). Such wireless communication can be achieved by any suitable means, including but not limited to standard communication protocols (e.g., The communication protocol is used. In various embodiments, wireless communication between the transmitter unit 104 and the external device 464 may alternatively be carried out by means of near field communication (NFC), radio frequency (RF) communication, infrared (IR) communication, or optical communication. In some embodiments, the transmitter unit 104 and the external device 464 may be connected by one or more wires.

[0102] Now for reference Figure 4B It shows something similar to Figure 4A The analyte monitoring system 400 shown is an example of an analyte monitoring system 400A with different component partitions. In the analyte monitoring system 400A, the transmitter unit 104A includes a bias circuit 444 and a current measurement circuit 446 coupled to the sensor assembly 126. The transmitter unit 104A may include a processor 450A configured to transmit instructions to and / or from the bias circuit 444, and to receive a current measurement signal I from the current measurement circuit 446. MEAS The processor 450A can also be configured to receive information stored in the sensor memory circuit 142, as described above. Additionally, the processor 450A can be configured to receive and / or transmit data via the transmit / receive circuit 470A. The processor 450A in the transmitter unit 104A of the analyte monitoring system 400A may not perform [the following action / function]. Figure 4A All functions of the processor 450 in the analyte monitoring system 400.

[0103] The analyte monitoring system 400A may include an external device 464A (e.g., an external receiver device), which may be more than Figure 4A The external device 464 of the analyte monitoring system 400 performs further analysis. The analyte monitoring system 400A can be coupled with... Figure 4A The analyte monitoring system 400 operates in a similar manner, except that the analyte concentration level can be calculated in an external device 464A. In some embodiments, the external device 464A may include sampling circuitry 448 and a gain function 456, which may be stored in receiver memory 480. Processor 466 may be coupled to receiver memory 480 and may receive sensor information stored in sensor memory circuitry 142 and may store such information in receiver memory 480. The wearable device 100A of the analyte monitoring system 400A may be more... Figure 4A The wearable device is smaller and lighter, and therefore less invasive, because it does not include the sampling circuitry 448 and memory 454. Other component configurations can be used. For example, as Figure 4B In a variation of the transmitter unit 104, the sampling circuit 448 can be retained in the transmitter unit 104, allowing the external device 464A to receive the current measurement signal I from the transmitter unit 104 in digital format. MEAS .

[0104] Figure 5 This is a flowchart illustrating an example of a method 500 for manufacturing a base unit 102 of a wearable device 100, 100A according to embodiments provided herein. Method 500 begins at block 502, assembling a sensor assembly 126 into the base unit 102. In some embodiments, sensor memory circuitry 142 may be assembled into the base unit 102 at this time. In block 504, the sensor assembly 126 and other components of the base unit 102 may be calibrated. In some embodiments, calibration may include measuring or calculating one or more parameters of the sensor assembly 126 and / or one or more other components of the base unit 102. For example, calibration may include measuring or calculating sensitivity parameters (e.g., one or more sensitivity slopes) of the biosensor 108 and / or other components of the sensor assembly 126. Sensitivity parameters may include one or more mathematical functions or one or more coefficients, which may be obtained, for example, by testing the sensor assembly 126. Each biosensor and / or sensor assembly may be unique with respect to at least its sensitivity and other parameters.

[0105] In block 506, calibration data and / or other data (sensor information) are written to sensor memory circuitry 142. For example, a computer or similar device may be coupled to contact pad 144 of sensor memory circuitry 142 to write information to sensor memory circuitry 142. In some embodiments, the information stored on sensor memory circuitry 142 may include the manufacturing date of biosensor 108. In embodiments including more than one biosensor 108, the sensor information may include the manufacturing date of at least one biosensor. In some embodiments, the sensor information stored on sensor memory circuitry 142 may include the manufacturing date of one or more components of base unit 102. In some embodiments, the sensor information stored on sensor memory circuitry 142 may include at least one unique identifier of one or more components of base unit 102. For example, at least one unique identifier may include a batch number and / or serial number. In some embodiments, the sensor information stored on sensor memory circuitry 142 may include a security code, wherein base unit 102 and / or components located thereon can only be accessed using the security code. In some embodiments, the sensor information stored in sensor memory circuitry 142 may include the sensor memory version of sensor memory circuitry 142.

[0106] In some embodiments, method 500 may optionally include block 508, wherein sensor information stored in sensor memory circuitry 142 is recorded and stored in a manufacturer's database or another database. Thus, the manufacturer of base unit 102 can access information relating to individual base units 102.

[0107] In block 510, the base unit 102 is sealed and packaged. For example, the base unit 102 may be sealed to prevent contaminants from entering the base unit 102. In some embodiments, sealing may include making the base unit 102 waterproof. The base unit 102 may then be packaged in a package that can be sent to a user of the base unit 102. The base unit may be sterilized before or after packaging, as described herein. In some embodiments, the package may be hermetically sealed. Other methods of sealing the package may prevent contaminants, including biological materials, from contacting the base unit 102. In block 512, if the base unit 102 has not yet been sterilized, it may be sterilized. In embodiments where the base unit 102 is in a package (e.g., a sealed package), the base unit 102 may be sterilized while it is in the package. Sterilization may include exposing the base unit 102 to radiation. As described above, the sensor memory circuitry 142 may be radiation-resistant so that it will not be damaged or erased when exposed to radiation. In some embodiments, the packaging surrounding the sensor memory circuitry 142 may provide radiation resistance.

[0108] In some embodiments, gamma ray or electron beam sterilization or another sterilization method may be used to sterilize one or more components of the base unit 102 (e.g., sensor assembly 126 and / or sensor memory circuitry 142). Example packaging may include a plastic housing with a removable plastic or foil seal, but any suitable packaging may be used.

[0109] The wearable device 100 can be used by: removing the sterilized base unit from its aseptic packaging; connecting the transmitter units 104, 104A and the base unit 102 together; removing the adhesive strip from the second side 122B of the adhesive layer 122; and inserting the biosensor 108 into the user using an insertion device (not shown) when attaching the base unit 102 to the user's skin surface 118S. Any suitable insertion device can be used to insert the biosensor 108 into the user's tissue fluid area.

[0110] Now for reference Figure 6 This figure is a flowchart of an example of a method 600 for continuous analyte monitoring according to embodiments provided herein. Method 600 begins at block 602, attaching a base unit 102 having a sensor assembly 126 and sensor memory circuitry 142 located therein to a user's skin surface 118S. A biosensor 108 is inserted into a tissue fluid region, and the base unit 102 can be attached to the user via an adhesive layer 122 attached to a second surface 110B of a substrate 110. For example, a second side 122B of the adhesive layer 122 can adhere to the user's skin surface 118S, such that the base unit 102 adheres to the skin surface 118S.

[0111] In block 604, transmitter unit 104 is coupled to base unit 102. In block 606, base unit 102 is activated. For example, power can be applied to sensor assembly 126 and / or sensor memory circuitry 142 via battery 312. In embodiments where battery 312 is located in transmitter unit 104, base unit 102 can be activated when base unit 102 and transmitter unit 104 are coupled together. In embodiments where battery is located in base unit 102, coupling transmitter unit 104 and base unit 102 together allows the battery to activate base unit 102. Other suitable activation methods can be used, such as receiving cues or signals from external devices 464, 464A.

[0112] In block 608, sensor information stored in sensor memory circuitry 142 is read or otherwise output. In some embodiments, in block 606, sensor memory circuitry 142 may output information when base unit 102 is activated. Figure 4A In the embodiment, with the processing current measurement signal I MEASThe relevant sensor information and gain function 456 can be output to the memory 454 in the transmitter unit 104, where the analyte concentration can be calculated at least partially. Figure 4B In this embodiment, the gain function 456 can be output to the processor 466 in the external device 464A. Other sensor information (e.g., manufacturing date, model, etc.) can be processed and displayed on the local display 460 and / or display 468.

[0113] Decision box 610 illustrates optional queries that can be performed on sensor information. In decision box 610, it is determined whether sensor component 126 has expired. For example, it can be determined whether the time period between the manufacturing date of sensor component 126 and the current date is greater than a predetermined time period. If sensor component 126 has expired, processing can proceed to box 612, where an error code can be generated. The error code can indicate that sensor component 126 has expired. As described herein, other error codes can be displayed in box 612.

[0114] In some embodiments, sensor information may include the model number of base unit 102 as described above, and a decision box may determine whether base unit 102 is the correct model number. If base unit 102 is not the correct model number, box 612 may generate an error code. In some embodiments, sensor information may include a security code as described above. The decision box may compare the security code with known codes, such as codes stored in memory 454 and / or receiver memory 480 and / or codes entered by the user. If the security code and other codes do not match, an error code may be generated. The security code may prevent the use of illegally manufactured or unauthorized base units in the wearable device 100.

[0115] If the result of decision box 610 is negative, processing can proceed to box 614, where transmitter units 104, 104A, and base unit 102 are used to monitor analyte levels in the user's body for a first predetermined time period. The operation of analyte monitoring can be continuous, meaning continuous sensing at a predetermined rate or as instructed by the user within the predetermined time period. For example, transmitter units 104, 104A, and base unit 102 can be used to monitor glucose or other analyte levels for 7 days, 10 days, 14 days, or another number of days. At the end of the time period, base unit 102 can be replaced by a new base unit. Sensor information stored in the new base unit can be read and can replace sensor information from the previous base unit 102. Therefore, the processing of analyte levels will be based on calibration information and sensor information specific to the new base unit 102.

[0116] The wearable device described herein can be used to monitor the concentration of any desired analyte. Example analytes that can be detected and / or monitored include glucose, cholesterol, lactate, uric acid, alcohol, etc. In some embodiments, sensor assembly 126 and / or biosensor 108 can operate continuously at a constant potential against a reference electrode (e.g., an Ag / AgCl electrode) or a combination of reference-counter electrodes. Sensor assembly 126 and / or biosensor 108 can also operate with two working electrodes, one dedicated to measuring the analyte of interest, such as glucose, via a glucose-specific enzyme (e.g., glucose oxidase). The other electrode is dedicated to measuring the background signal generated by interfering substances (e.g., uric acid, acetaminophen, etc.). In this dual-electrode operation scheme, interfering signals can be continuously subtracted from the main signal of the analyte of interest by simple subtraction or another calculation method.

[0117] Although transmitter units 104, 104A are shown as removable and / or attachable to the top surface of base unit 102, it should be understood that in other embodiments, transmitter units 104, 104A may be removable and / or insertable into other surfaces or regions of base unit 102. For example, according to some embodiments, base unit 102 may have an opening that allows transmitter units 104 to be inserted into or removed from the bottom or side of base unit 102. In other embodiments, base unit 102 may include an opening configured to receive transmitter units 104. In such embodiments, a recess may be formed to cover the opening including transmitter units 104.

[0118] Now for reference Figure 7 The figure is a flowchart illustrating a method 700 for manufacturing a base unit (e.g., base unit 102) of a continuous analyte monitor (e.g., wearable device 100). Method 700 includes assembling a sensor assembly (e.g., sensor assembly 126) to a substrate (e.g., substrate 110) in block 702. Method 700 also includes assembling sensor memory circuitry (e.g., sensor memory circuitry 142) to the substrate in block 704. The method further includes determining at least one parameter of at least one component of the base unit in block 706. Method 700 also includes storing information of at least one parameter in the sensor memory circuitry in block 708. In some embodiments, method 700 includes sterilizing the base unit in block 710.

[0119] For reference Figure 8The figure is a flowchart illustrating a method 800 for subcutaneous monitoring of an analyte. Method 800 includes inserting a biosensor (e.g., biosensor 108) extending from a base unit (e.g., base unit 102) of a wearable device (e.g., wearable device 100) into subcutaneous tissue fluid in block 802. Method 800 also includes coupling the base unit and a transmitter unit (e.g., transmitter unit 104) of the wearable device together in block 804. Method 800 further includes transmitting information stored in a sensor memory circuit (e.g., sensor memory circuit 142) in the base unit to the transmitter unit in block 806, the information including at least one parameter of at least one component of the base unit. Method 800 also includes measuring a current passing through the biosensor in block 808. Method 800 further includes determining the analyte concentration based at least partially on the current and the information in block 810.

[0120] The embodiments provided herein allow for flexible and ultra-low profile wearable units. In some embodiments, the height of the wearable unit can be less than about 2.5 mm. This reduction in overall height reduces interference with clothing, makes the unit more compact, and improves the overall comfort of the wearer. Flexible construction and components allow the wearable unit to conform to the user's body throughout a range of movements and enhance overall user comfort. Key components can be supported by rigid reinforcements at specific locations while maintaining overall flexibility.

[0121] The wearable device described herein further enables accurate analyte monitoring using transmitter units connected to multiple different base units 102 throughout the service life of transmitter units 104, 104A. Accurate analyte monitoring is achieved by storing unique information about one or more parameters of one or more components of an individual base unit, regardless of the base unit connected to the transmitter unit.

[0122] In some embodiments, the materials used (e.g., LSR), flexible circuit boards (e.g., substrate 152 – FIG. 1), etc., provide a wearable device 100 that can be comfortably worn under clothing, has a low profile and avoids impact, presents a soft and flexible touch and appearance, and changes its profile and movement in response to the dynamics of tissue flexion, expansion, and contraction. The disclosed device also protects sensor areas and internal hardware from fluid ingress and other hazards of use, is easy and comfortable to apply, provides breathability / airflow in skin-adhesive areas, and produces a generally more user-friendly experience.

[0123] The foregoing description discloses only exemplary embodiments. Modifications to the devices and methods disclosed above that fall within the scope of this disclosure will be readily apparent to those skilled in the art.

Claims

1. A base unit for a wearable device configured for use during continuous analyte monitoring, comprising: A sensor assembly, the sensor assembly including at least one biosensor configured to be located under the skin; as well as A radiation-hardened sensor memory circuit, the radiation-hardened sensor memory circuit being configured to store information relating to at least one parameter of at least one component of the base unit; wherein: The at least one component includes the biosensor. The at least one parameter includes one or more sensitivity slopes of the at least one biosensor; In response to the physical connection between the base unit and the transmitter unit, the information stored in the radiation-hardened sensor memory circuit of the base unit can be automatically transmitted to the transmitter unit without user input; The radiation-hardened sensor memory circuit includes a data contact pad and a radiation-hardened memory, the data contact pad being used to transmit the information to the transmitter unit via a connector, and the radiation-hardened memory storing the information and retaining the information when exposed to radiation used for sterilizing the base unit; The connector is electrically connected to the data contact pad and configured to electrically connect the radiation-hardened sensor memory circuitry to the transmitter unit. The connector includes at least one electrode that is axially movable within the connector and biased relative to the connector to make electrical contact with components within the base unit and / or the transmitter unit.

2. The base unit according to claim 1, wherein the at least one parameter includes at least one parameter selected from the following: The manufacturing date of at least one component in the base unit. The manufacturing date of the base unit, At least one unique identifier for at least one component of the base unit. Security code, operable to enable the transmitter unit to function in conjunction with the base unit. The version of the radiation-hardened sensor memory circuit, and The serial number of at least one component of the base unit.

3. The base unit of claim 1, wherein the connector is configured to electrically connect the radiation-hardened sensor memory circuitry to at least one component in the transmitter unit in response to the base unit and the transmitter unit being coupled together.

4. The base unit of claim 1, wherein the connector is configured to electrically connect the sensor assembly to at least one component in the transmitter unit in response to the base unit and the transmitter unit being coupled together.

5. The base unit of claim 1, wherein the radiation-hardened sensor memory circuit is configured to transmit the information to at least one component in the transmitter unit in response to the base unit and the transmitter unit being coupled together.

6. The base unit of claim 1, wherein at least one of the sensor assembly and the radiation-hardened sensor memory circuit is configured to be powered by a power source located in the transmitter unit.

7. The base unit of claim 1, wherein at least one of the sensor assembly and the radiation-hardened sensor memory circuit is configured to receive power in response to the base unit and the transmitter unit being coupled together.

8. The base unit according to claim 1, wherein the base unit is sterilized by exposure to radiation.

9. The base unit according to claim 1, wherein the at least one biosensor is configured to measure glucose.

10. The base unit according to claim 1, wherein the radiation-hardened sensor memory circuit has two external nodes consisting of a data node and a ground node.

11. A transmitter unit for a wearable device used during continuous analyte monitoring, comprising: One or more components, the one or more components being configured to respond to the transmitter unit and According to claim 1, the base units of the wearable device are physically connected together and automatically receive information stored in the radiation-hardened sensor memory circuitry of the base units without user input. The information includes at least one parameter of at least one component of the base unit, wherein the base unit includes at least one biosensor configured to be located under the skin, and wherein the at least one parameter includes one or more sensitivity slopes of the at least one biosensor; The radiation-hardened sensor memory circuit includes a data contact pad and a radiation-hardened memory, the data contact pad being used to transmit the information to the transmitter unit via a connector, and the radiation-hardened memory storing the information and retaining the information when exposed to radiation used for sterilizing the base unit; The connector is electrically connected to the data contact pad and configured to electrically connect the radiation-hardened sensor memory circuitry to the transmitter unit. The connector includes at least one electrode that is axially movable within the connector and biased relative to the connector to make electrical contact with components within the base unit and / or the transmitter unit.

12. The transmitter unit of claim 11, wherein the at least one parameter includes at least one parameter selected from the following: The manufacturing date of at least one component in the base unit. The manufacturing date of the base unit, At least one unique identifier for at least one component of the base unit. Security code, The version of the radiation-hardened sensor memory circuit, and The serial number of at least one component of the base unit.

13. The transmitter unit of claim 11, further comprising a power supply configured to provide power to the radiation-hardened sensor memory circuitry in response to the transmitter unit and the base unit being coupled together.

14. A wearable device for use during continuous analyte monitoring, comprising: The base unit according to claim 1; as well as The transmitter unit according to claim 11; The base unit includes a sensor assembly and a sensor memory circuit. The sensor assembly is configured to measure an analyte in tissue fluid, and the radiation-hardened sensor memory circuit is configured to store information about at least one parameter of at least one component in the base unit. The base unit includes at least one biosensor configured to be located subcutaneously, and the at least one parameter includes one or more sensitivity slopes of the at least one biosensor. In response to the physical connection between the base unit and the transmitter unit, the information can be automatically transferred from the radiation-hardened sensor memory circuit without user input.

15. The wearable device of claim 14, wherein the base unit is sterilized by exposure to radiation.

16. A method of manufacturing a base unit for a wearable device used during continuous analyte monitoring as claimed in claim 1, comprising: A sensor assembly is assembled onto a substrate, the sensor assembly including at least one biosensor configured to be located under the skin; Radiation-hardened sensor memory circuitry is assembled onto the substrate; Determine at least one parameter of at least one component of the base unit; as well as The information of at least one parameter is stored in the radiation-hardened sensor memory circuit.

17. The method of claim 16, wherein determining at least one parameter comprises determining at least one parameter selected from: The sensitivity of the at least one biosensor; The manufacturing date of at least one component in the base unit. The manufacturing date of the base unit, At least one unique identifier for at least one component in the base unit. Security code, Sensor memory version, and The serial number of at least one component in the base unit.

18. A method for subcutaneous monitoring of analytes using a wearable device as described in claim 14 during continuous analyte monitoring, comprising: A biosensor extending from the base unit of the wearable device is inserted into the subcutaneous tissue fluid; The base unit and the transmitter unit of the wearable device are physically connected together; In response to the physical connection between the base unit and the transmitter unit, information stored in the radiation-hardened sensor memory circuit in the base unit is automatically transmitted to the transmitter unit without user input, the information including at least one parameter of at least one component of the base unit; Measure the current passing through the biosensor; as well as The concentration of the analyte is determined at least in part based on the current and the information.

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