Patent Description:
Aspects of the present invention relate to systems and methods for analyte monitoring. Specifically, aspects of the present invention may relate to environmental detection and/or temperature compensation in an analyte monitoring system. More specifically, the temperature compensation may be lag cognizant.

The prevalence of diabetes mellitus continues to increase in industrialized countries, and projections suggest that this figure will rise to <NUM>% of the global population (<NUM> million individuals) by the year <NUM>. Glycemic control is a key determinant of long-term outcomes in patients with diabetes, and poor glycemic control is associated with retinopathy, nephropathy and an increased risk of myocardial infarction, cerebrovascular accident, and peripheral vascular disease requiring limb amputation. Despite the development of new insulins and other classes of antidiabetic therapy, roughly half of all patients with diabetes do not achieve recommended target hemoglobin A1c (HbA1c) levels < <NUM>%.

Frequent self-monitoring of blood glucose (SMBG) is necessary to achieve tight glycemic control in patients with diabetes mellitus, particularly for those requiring insulin therapy. However, current blood (finger-stick) glucose tests are burdensome, and, even in structured clinical studies, patient adherence to the recommended frequency of SMBG decreases substantially over time. Moreover, finger-stick measurements only provide information about a single point in time and do not yield information regarding intraday fluctuations in blood glucose levels that may more closely correlate with some clinical outcomes.

Continuous glucose monitors (CGMs) have been developed in an effort to overcome the limitations of finger-stick SMBG and thereby help improve patient outcomes. These systems enable increased frequency of glucose measurements and a better characterization of dynamic glucose fluctuations, including episodes of unrealized hypoglycemia. Furthermore, integration of CGMs with automated insulin pumps allows for establishment of a closed-loop "artificial pancreas" system to more closely approximate physiologic insulin delivery and to improve adherence.

Glucose monitors are known from <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>.

Monitoring real-time analyte measurements from a living body via wireless analyte monitoring sensor(s) may provide numerous health and research benefits. There is a need to enhance such analyte monitoring systems via innovations.

One aspect of the disclosure may provide an analyte monitoring system including an analyte sensor and a transceiver. The analyte sensor may include one or more sensor elements and a transceiver interface. The one or more sensor elements may be configured to generate one or more sensor measurements indicative of an analyte level in a first medium. The transceiver interface may be configured to convey the one or more sensor measurements. The transceiver may include a sensor interface, one or more environmental sensors, and a processor. The sensor interface may be configured to receive the one or more sensor measurements conveyed by the analyte sensor. The one or more environmental sensors may be configured to generate one or more environment measurements. The processor may be configured to calculate an analyte level in a second medium using at least the one or more sensor measurements and the one or more environmental measurements.

Another aspect of the disclosure may provide an analyte monitoring system including an analyte sensor, one or more environmental sensors, and a transceiver. The analyte sensor may include one or more sensor elements and a transceiver interface. The one or more sensor elements may be configured to generate one or more sensor measurements indicative of an analyte level in a first medium. The transceiver interface may be configured to convey the one or more sensor measurements. The one or more environmental sensors may be configured to generate one or more environment measurements. The transceiver may be configured to receive the one or more environmental measurements. The transceiver may include a sensor interface and a processor. The sensor interface may be configured to receive the one or more sensor measurements conveyed by the analyte sensor. The processor may be configured to calculate an analyte level in a second medium using at least the one or more sensor measurements and the one or more environmental measurements.

In some aspects, the one or more environmental sensors may include a posture detector, the one or more environmental measurements may include one or more posture measurements indicative of a posture of a user of the transceiver, and the processor may be configured to calculate the analyte level in the second medium using at least the one or more sensor measurements and the one or more posture measurements. In some aspects, the posture detector may include an accelerometer and a barometer, the one or more posture measurements may include one or more acceleration measurements and one or more atmospheric measurements, and calculating the analyte level in the second medium using at least the one or more sensor measurements and the one or more posture measurements may include: (i) calculating a posture of the user of the transceiver using at least the one or more posture measurements; and (ii) calculating the analyte level in the second medium using at least the one or more sensor measurements and the calculated posture. In some aspects, calculating the analyte level in the second medium using at least the one or more sensor measurements and the calculated posture may include: adjusting one or more parameters of a conversion function based on at least the calculated posture; and using the adjusted conversion function and the one or more sensor measurements to calculate the analyte level in the second medium.

In some aspects, the one or more environmental sensors may include a pressure sensor, the one or more environmental measurements may include one or more pressure measurements indicative of pressure on the transceiver, and the processor may be configured to calculate the analyte level in the second medium using at least the one or more sensor measurements and the one or more pressure measurements. In some aspects, the pressure sensor may include a button. In some aspects, calculating the analyte level in the second medium using at least the one or more sensor measurements and the one or more pressure measurements may include: adjusting one or more parameters of a conversion function based on at least the one or more pressure measurements; and using the adjusted conversion function and the one or more sensor measurements to calculate the analyte level in the second medium.

In some aspects, the one or more environmental sensors may include an accelerometer, the one or more environmental measurements may include one or more acceleration measurements generated by the accelerometer, and the processor may be configured to calculate the analyte level in the second medium using at least the one or more sensor measurements and the one or more acceleration measurements. In some aspects, calculating the analyte level in the second medium using at least the one or more sensor measurements and the one or more acceleration measurements may include: determining whether a shock to the transceiver has occurred using at least the one or more acceleration measurements; and calculating the analyte level in the second medium using at least the one or more sensor measurements and the determination of whether a shock to the transceiver has occurred. In some aspects, calculating the analyte level in the second medium using at least the one or more sensor measurements and the determination of whether a shock to the transceiver has occurred may include: adjusting one or more parameters of a conversion function based on at least the determination of whether a shock to the transceiver has occurred; and using the adjusted conversion function and the one or more sensor measurements to calculate the analyte level in the second medium.

In some aspects, the one or more environmental sensors may include a temperature sensor, the one or more environmental measurements may include one or more temperature measurements generated by the temperature sensor, and the processor may be configured to calculate the analyte level in the second medium using at least the one or more sensor measurements and the one or more temperature measurements. In some aspects, calculating the analyte level in the second medium using at least the one or more sensor measurements and the one or more temperature measurements may include: adjusting at least a sensor measurement of the one or more sensor measurements based on the one or more temperature measurements; and using the one or more sensor measurements including the adjusted sensor measurement to calculate the analyte level in the second medium.

In some aspects, the transceiver may be further configured to use at least one or more of the one or more environmental measurements to adjust a sampling frequency of one or more of the one or more environmental sensors. In some aspects, the transceiver may be further configured to: use at least one or more of the one or more environmental measurements to determine whether an environmental event has occurred; and, if the transceiver determines that the environmental event has occurred, cause the transceiver or a display device to display an icon indicative of the environmental event.

Another aspect of the disclosure may provide a method including using one or more sensor elements of an analyte sensor to generate one or more sensor measurements indicative of an analyte level in a first medium. The method may include using a transceiver interface of the analyte sensor to convey the one or more sensor measurements. The method may include using a sensor interface of a transceiver to receive the one or more sensor measurements conveyed by the analyte sensor. The method may include using one or more environmental sensors of the transceiver to generate one or more environment measurements. The method may include using the transceiver to calculate an analyte level in a second medium using at least the one or more sensor measurements and the one or more environmental measurements.

In some aspects, the one or more environmental sensors may include a posture detector, the one or more environmental measurements may include one or more posture measurements indicative of a posture of a user of the transceiver, and the transceiver may calculate the analyte level in the second medium using at least the one or more sensor measurements and the one or more posture measurements. In some aspects, the posture detector may include an accelerometer and a barometer, the one or more posture measurements may include one or more acceleration measurements and one or more atmospheric measurements, and calculating the analyte level in the second medium using at least the one or more sensor measurements and the one or more posture measurements may include: calculating a posture of the user of the transceiver using at least the one or more posture measurements; and calculating the analyte level in the second medium using at least the one or more sensor measurements and the calculated posture. In some aspects, calculating the analyte level in the second medium using at least the one or more sensor measurements and the calculated posture may include: adjusting one or more parameters of a conversion function based on at least the calculated posture; and using the adjusted conversion function and the one or more sensor measurements to calculate the analyte level in the second medium.

In some aspects, the one or more environmental sensors may include a pressure sensor, the one or more environmental measurements may include one or more pressure measurements indicative of pressure on the transceiver, and the transceiver may calculate the analyte level in the second medium using at least the one or more sensor measurements and the one or more pressure measurements. In some aspects, calculating the analyte level in the second medium using at least the one or more sensor measurements and the one or more pressure measurements may include: adjusting one or more parameters of a conversion function based on at least the one or more pressure measurements; and using the adjusted conversion function and the one or more sensor measurements to calculate the analyte level in the second medium.

In some aspects, the one or more environmental sensors may include an accelerometer, the one or more environmental measurements may include one or more acceleration measurements, and the transceiver may calculate the analyte level in the second medium using at least the one or more sensor measurements and the one or more acceleration measurements. In some aspects, calculating the analyte level in the second medium using at least the one or more sensor measurements and the one or more acceleration measurements may include: determining whether a shock to the transceiver has occurred using at least the one or more acceleration measurements; and calculating the analyte level in the second medium using at least the one or more sensor measurements and the determination of whether a shock to the transceiver has occurred. In some aspects, calculating the analyte level in the second medium using at least the one or more sensor measurements and the determination of whether a shock to the transceiver has occurred may include: adjusting one or more parameters of a conversion function based on at least the determination of whether a shock to the transceiver has occurred, and using the adjusted conversion function and the one or more sensor measurements to calculate the analyte level in the second medium.

In some aspects, the method may include using at least one or more of the one or more environmental measurements to adjust a sampling frequency of one or more of the one or more environmental sensors. In some aspects, the method may include using at least one or more of the one or more environmental measurements to determine that an environmental event has occurred, and displaying an icon indicative of the environmental event.

Still another aspect of the disclosure may provide an analyte monitoring system including an analyte sensor and a transceiver. The analyte sensor may include one or more sensor elements and a transceiver interface. The one or more sensor elements may be configured to generate sensor measurements indicative of an analyte level in a first medium. The sensor elements may include a temperature transducer configured to generate a sensor temperature measurement. The sensor measurements may include the sensor temperature measurement. The transceiver interface may be configured to convey the sensor measurements.

In some embodiments, the analyte sensor may further include a housing and an analyte indicator on or in at least a portion of an exterior surface of the sensor housing. In some embodiments, the sensor temperature measurement may be a measurement of temperature inside the housing of the analyte sensor, and the adjusted sensor temperature measurement may be an estimate of a temperature of the analyte indicator. In some embodiments, the adjusted sensor temperature measurement may account for a lag between the temperature inside the housing of the analyte sensor and the temperature of the analyte indicator.

In some embodiments, adjusting the sensor temperature measurement may include calculating a rate of change of the temperature of the analyte sensor using at least the sensor temperature measurement and one or more sensor temperature measurements received previously from the analyte sensor. In some embodiments, calculating the analyte level in the second medium using at least the adjusted sensor temperature measurement and the one or more of the sensor measurements may include calculating an analyte level in the first medium using at least the adjusted sensor temperature measurement and the one or more of the sensor measurements and calculating the analyte level in the second medium using at least the calculated analyte level in the first medium.

In some embodiments, the analyte monitoring system may further include a temperature sensor configured to generate a temperature measurement, and the processor may be configured to adjust the sensor temperature measurement using at least the temperature measurement generated by the temperature sensor. In some embodiments, the transceiver may include the temperature sensor. In some embodiments, the adjusted sensor temperature measurement may account for a lag between a temperature measured by the temperature sensor and the temperature of the analyte indicator. In some embodiments, adjusting the sensor temperature measurement may include calculating a rate of change of the temperature of the transceiver using at least the temperature measurement generated by the temperature sensor and one or more temperature measurements generated previously by the temperature sensor. In some embodiments, adjusting the sensor temperature measurement may include calculating the adjusted sensor temperature measurement using at least the temperature measurement generated by the temperature sensor and the calculated rate of change of the temperature of the transducer. In some embodiments, adjusting the sensor temperature measurement may include calculating a rate of change of the temperature of the analyte sensor using at least the sensor temperature measurement and one or more sensor temperature measurements received previously from the analyte sensor, and calculating the adjusted sensor temperature measurement may use at least the sensor temperature measurement, the calculated rate of change of the temperature of the analyte sensor, the temperature measurement generated by the temperature sensor, and the calculated rate of change of the temperature of the transducer.

Yet another aspect of the disclosure may provide a method including using one or more sensor elements of an analyte sensor to generate sensor measurements indicative of an analyte level in a first medium. The sensor elements may include a temperature transducer, and the sensor measurements may include a sensor temperature measurement generated by the temperature transducer. The method may include using a transceiver interface of the analyte sensor to convey the sensor measurements. The method may include using a sensor interface of a transceiver to receive the sensor measurements conveyed by the analyte sensor. The method may include using the transceiver to adjust the sensor temperature measurement. The method may include using the transceiver to calculate an analyte level in a second medium using at least the adjusted sensor temperature measurement and one or more of the sensor measurements.

In some embodiments, the analyte sensor may further include a housing and an analyte indicator on or in at least a portion of an exterior surface of the sensor housing, the sensor temperature measurement may be a measurement of temperature inside the housing of the analyte sensor, and the adjusted sensor temperature measurement may be an estimate of a temperature of the analyte indicator. In some embodiments, the adjusted sensor temperature measurement may account for a lag between the temperature inside the housing of the analyte sensor and the temperature of the analyte indicator.

In some embodiments, adjusting the sensor temperature measurement may include calculating a rate of change of the temperature of the analyte sensor using at least the sensor temperature measurement and one or more sensor temperature measurements received previously from the analyte sensor. In some embodiments, adjusting the sensor temperature measurement may include calculating the adjusted sensor temperature measurement using at least the sensor temperature measurement and the calculated rate of change of the temperature of the analyte sensor. In some embodiments, calculating the analyte level in the second medium using at least the adjusted sensor temperature measurement and the one or more of the sensor measurements may include calculating an analyte level in the first medium using at least the adjusted sensor temperature measurement and the one or more of the sensor measurements and calculating the analyte level in the second medium using at least the calculated analyte level in the first medium.

In some embodiments, the method may further include using a temperature sensor to generate a temperature measurement, wherein the processor is configured to adjust the sensor temperature measurement using at least the temperature measurement generated by the temperature sensor. In some embodiments, the adjusted sensor temperature measurement may account for a lag between a temperature measured by the temperature sensor and the temperature of the analyte indicator. In some embodiments, adjusting the sensor temperature measurement may include calculating a rate of change of the temperature of the transceiver using at least the temperature measurement generated by the temperature sensor and one or more temperature measurements generated previously by the temperature sensor. In some embodiments, adjusting the sensor temperature measurement may include calculating the adjusted sensor temperature measurement using at least the temperature measurement generated by the temperature sensor and the calculated rate of change of the temperature of the transducer. In some embodiments, adjusting the sensor temperature measurement may include calculating a rate of change of the temperature of the analyte sensor using at least the sensor temperature measurement and one or more sensor temperature measurements received previously from the analyte sensor, and calculating the adjusted sensor temperature measurement may use at least the sensor temperature measurement, the calculated rate of change of the temperature of the analyte sensor, the temperature measurement generated by the temperature sensor, and the calculated rate of change of the temperature of the transducer.

Further variations encompassed within the systems and methods are described in the detailed description of the invention below.

The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various, non-limiting embodiments of the present invention. In the drawings, like reference numbers indicate identical or functionally similar elements.

<FIG> and <FIG> are schematic views of an exemplary analyte monitoring system <NUM> embodying aspects of the present invention. The analyte monitoring system <NUM> may be a continuous analyte monitoring system (e.g., a continuous glucose monitoring system). In some embodiments, as shown in <FIG> and <FIG>, the system <NUM> may include one or more of an analyte sensor <NUM>, a transceiver <NUM>, and a display device <NUM>. In some embodiments, the sensor <NUM> and transceiver <NUM> may include one or more of the structural and/or functional features described in one or more of <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>.

In some embodiments, as shown in <FIG>, the sensor <NUM> may be small, fully subcutaneously implantable sensor that measures analyte (e.g., glucose, oxygen, cardiac markers, low-density lipoprotein (LDL), high-density lipoprotein (HDL), or triglycerides) levels in a medium (e.g., interstitial fluid) of a living animal (e.g., a living human). However, this is not required, and, in some alternative embodiments, the sensor <NUM> may be a partially implantable (e.g., transcutaneous) sensor or a fully external sensor. In some embodiments, the transceiver <NUM> may be a handheld or body-worn transceiver (e.g., attached via an armband, wristband, waistband, or adhesive patch). In some embodiments, as shown in <FIG>, the transceiver <NUM> may remotely power and/or communicate with the sensor to initiate and receive the measurements (e.g., via near field communication (NFC)). However, this is not required, and, in some alternative embodiments, the transceiver <NUM> may power and/or communicate with the sensor <NUM> via one or more wired connections. In some non-limiting embodiments, the transceiver <NUM> may be a smartphone (e.g., an NFC-enabled smartphone). In some embodiments, the transceiver <NUM> may communicate information (e.g., one or more analyte levels) wirelessly (e.g., via a Bluetooth™ communication standard such as, for example and without limitation Bluetooth Low Energy) to a hand held application running on a display device <NUM> (e.g., smartphone).

In some embodiments, the transceiver <NUM> may convey (e.g., periodically, such as every two or five minutes, and/or upon user initiation) measurement commands (i.e., requests for measurement information) to the sensor <NUM>. In some embodiments where the transceiver <NUM> is a handheld device, positioning (i.e., hovering or swiping/waving/passing) the transceiver <NUM> within range over the sensor implant site (i.e., within proximity of the sensor <NUM>) may cause the transceiver <NUM> to automatically convey a measurement command to the sensor <NUM> and receive one or more sensor measurements conveyed by the sensor <NUM>.

In some embodiments, as illustrated in <FIG>, the analyte sensor <NUM> may include a transceiver interface <NUM> that the analyte sensor <NUM> may use to communicate with the transceiver <NUM>, and the transceiver <NUM> may include a sensor interface <NUM> that the transceiver <NUM> may use to communicate with the analyte sensor <NUM>. In some non-limiting embodiments, the transceiver interface <NUM> and the sensor interface <NUM> may each include one or more inductive elements, such as, for example, one or more coils. In some embodiments, the sensor interface <NUM> of the transceiver <NUM> may generate an electromagnetic wave or electrodynamic field (e.g., by using a coil) to induce a current in a transceiver interface <NUM> of the sensor <NUM>. In some non-limiting embodiments, the current induced in the transceiver interface <NUM> of the sensor <NUM> may be used to power the sensor <NUM>. In some embodiments, the current induced in the transceiver interface <NUM> of the sensor <NUM> may additionally or alternatively be used for communication. For example, in some embodiments, the transceiver <NUM> may use the sensor interface <NUM> to convey data (e.g., commands) to the sensor <NUM>. In some non-limiting embodiments, the transceiver <NUM> may use the sensor interface <NUM> to convey data by modulating the electromagnetic wave used to power the sensor <NUM> (e.g., by modulating the current flowing through a coil of the sensor interface <NUM> of the transceiver <NUM>). In some embodiments the modulation in the electromagnetic wave generated by the sensor interface <NUM> of the transceiver <NUM> may be detected/extracted by the sensor <NUM> (e.g., by the transceiver interface <NUM> of the sensor <NUM>). Moreover, the transceiver <NUM> may use the sensor interface <NUM> to receive sensor data (e.g., one or more sensor measurements) conveyed by the sensor <NUM>. For example, in some non-limiting embodiments, the transceiver <NUM> may receive sensor data by detecting modulations in the electromagnetic wave generated by the transceiver interface <NUM> of the sensor <NUM>, e.g., by detecting modulations in the current flowing through a coil of the sensor interface <NUM> of the transceiver <NUM>.

In some non-limiting embodiments, as shown in <FIG>, the analyte sensor <NUM> may include one or more sensor elements <NUM>. In some non-limiting embodiments, the sensor elements <NUM> may include an analyte indicator. In some embodiments, the analyte indicator may include one or more indicator molecules having one or more detectable properties that vary in accordance with the amount, level, or concentration of the analyte in proximity to the analyte indicator.

In some embodiments, the sensor <NUM> may be an optical sensor. However, this is not required, and, in one or more alternative embodiments, the sensor <NUM> may be a different type of analyte sensor, such as, for example, an electrochemical sensor, a diffusion sensor, or a pressure sensor. Also, although in some embodiments the analyte sensor <NUM> may be a fully implantable sensor, this is not required, and, in some alternative embodiments, the sensor <NUM> may be a transcutaneous sensor having a wired connection to the transceiver <NUM>. For example, in some alternative embodiments, the sensor <NUM> may be located in or on a transcutaneous needle (e.g., at the tip thereof). In these embodiments, instead of the sensor <NUM> and transceiver <NUM> wirelessly communicating using the transceiver interface <NUM> and sensor interface <NUM>, the transceiver interface <NUM> and sensor interface <NUM> may enable wired communication between the sensor <NUM> and transceiver <NUM>. In some non-limiting transcutaneous embodiments, one or more wires may be connected between the transceiver <NUM> and the transceiver transcutaneous needle that includes the sensor <NUM>. For another example, in some alternative embodiments, the sensor <NUM> may be located in a catheter (e.g., for intravenous blood glucose monitoring) and may communicate (wirelessly or using wires) with the transceiver <NUM>.

In some embodiments, as illustrated in <FIG>, the transceiver <NUM> may include one or more environmental sensors configured to generate one or more environmental measurements. In some embodiments, the one or more environmental sensors may include one or more of: (i) one or more posture sensors <NUM>, (ii) one or more pressure sensors <NUM>, (iii) one or more shock sensors <NUM>, and (iv) one or more temperature sensors <NUM>. In some embodiments, the one or more posture sensors <NUM> may generate one or more posture measurements indicative of the posture of a user of the transceiver <NUM>. In some embodiments, the one or more posture sensors <NUM> may include an accelerometer and a barometer. In some embodiments, the one or more pressure sensors <NUM> may generate one or more pressure measurements indicative of pressure on the transceiver <NUM> (e.g., due to the user of the transceiver <NUM> laying on the transceiver <NUM>). In some non-limiting embodiments, the one or more pressure measurements may indicate how much pressure is being applied to the transceiver <NUM>. In some alternative embodiments, the one or more pressure measurements may simply indicate whether the user is laying on the transceiver <NUM> (e.g., yes or no). In some embodiments, the one or more pressure sensors <NUM> may include one or more buttons (e.g., one or more buttons on the surface of the transceiver <NUM> that faces the user). In some embodiments, the one or more shock sensors <NUM> may include an accelerometer and generate one or more acceleration measurements. In some embodiments, the one or more acceleration measurements may be indicate of whether a shock to the transceiver <NUM> has occurred. In some embodiments, the one or more temperature sensors <NUM> may generate one or more temperature measurements indicative of the temperature of the transceiver <NUM>.

In some embodiments, the transceiver <NUM> may receive one or more measurements conveyed by the analyte sensor <NUM>. In some embodiments, the transceiver <NUM> may calculate one or more analyte levels using at least the one or more measurements conveyed by the analyte sensor <NUM>. In some embodiments, the transceiver <NUM> may additionally use one or more environmental measurements to calculate the one or more analyte levels. However, it is not required that the transceiver <NUM> perform the analyte level calculations itself, and, in some alternative embodiments, the transceiver <NUM> may instead convey/relay the measurement information received conveyed by the sensor <NUM> to another device (e.g., display device <NUM>) for calculation of analyte levels (e.g., by a mobile medical application executing on the display device <NUM>). In some non-limiting embodiments, the analyte level calculation may include one or more features described in <CIT>.

In some embodiments, the transceiver <NUM> and/or display device <NUM> may be configured to generate one or more alerts, alarms, or notifications based on the one or more analyte levels and/or the one or more environmental measurements. In some embodiments, one or more of the transceiver <NUM> and the display device <NUM> may communicate the alerts, alarms, and/or notifications to a user. In some embodiments, the alerts, alarms, and/or notifications may be visual, audible, and/or vibratory in nature.

In some embodiments, as shown in <FIG>, the transceiver <NUM> may include a display interface <NUM> that the transceiver <NUM> may use to communicate with the display device <NUM>, and the display device <NUM> may include a transceiver interface <NUM> that the display device <NUM> may use to communicate with the transceiver <NUM>. In some embodiments, the display interface <NUM> and transceiver interface <NUM> may enable wireless communication between the transceiver <NUM> and display device <NUM>. In some embodiments, the display interface <NUM> and transceiver interface <NUM> may communicate using one or more wireless protocols. In some non-limiting embodiments, the wireless protocols may include a Bluetooth protocol (e.g., an Bluetooth Low Energy (BLE) protocol). In some embodiments, the transceiver <NUM> may use the display interface <NUM> to communicate one or more analyte measurements, one or more analyte levels, one or more alerts, alarms, or notifications, and/or one or more environmental measurements to the display device <NUM>.

In some embodiments, the system <NUM> may include one or more displays. For example, in some embodiments, as shown in <FIG>, the display device <NUM> may include a display <NUM> configured to display one or more analyte levels, one or more alerts, alarms, or notifications, and/or one or more environmental measurements. In some embodiments, the transceiver <NUM> may additionally or alternatively include a display configured to display one or more analyte levels, one or more alerts, alarms, or notifications, and/or one or more environmental measurements.

In some embodiments, as shown in <FIG>, the transceiver <NUM> may include a display interface <NUM> configured to convey information (e.g., alerts and/or analyte levels) to one or more display devices <NUM>. In some embodiments, a display device <NUM> may be a portable and/or handheld device. In some embodiments, the display device <NUM> may be a smartphone. However, this is not required, and, in some alternative embodiments, the display device <NUM> may be a laptop computer, tablet, notebook, personal data assistant ("PDA"), personal computer, or a dedicated analyte monitoring display device. In some embodiments, the display device <NUM> may include a transceiver interface <NUM>, which may be configured to communicate with the display interface <NUM> of the transceiver <NUM> through a wired or wireless connection. In some embodiments, the display device <NUM> may include a processor <NUM>, and the processor <NUM> may be configured to execute a mobile medical application stored in a memory of the display device <NUM>.

<FIG> is a schematic view illustrating a non-limiting example of the sensor <NUM> and transceiver <NUM> of the analyte monitoring system <NUM> according some embodiments of the invention. In some embodiments, the sensor elements <NUM> of the sensor <NUM> may include one or more analyte indicators <NUM>, one or more light sources <NUM>, one or more photodetectors <NUM>, <NUM>, one or more temperature transducers <NUM>, a substrate <NUM>, an amplifier <NUM>, and/or an analog-to-digital converter (ADC) <NUM>. In some non-limiting embodiments, as illustrated in <FIG>, the sensor <NUM> may be encased in a sensor housing <NUM> (i.e., body, shell, capsule, or encasement), which may be rigid and biocompatible. In some embodiments, the analyte indicator <NUM> may be, for example and without limitation, a hydrogel or polymer graft coated, diffused, adhered, or embedded on or in at least a portion of the exterior surface of the sensor housing <NUM>. In some embodiments, the analyte indicator <NUM> (e.g., polymer graft) of the sensor <NUM> may include indicator molecules <NUM> (e.g., fluorescent indicator molecules) exhibiting one or more detectable properties (e.g., optical properties) based on the amount or concentration of the analyte in proximity to the analyte indicator <NUM>.

In some embodiments, as shown in <FIG>, the light source <NUM> may emit excitation light <NUM> over a range of wavelengths that interact with the indicator molecules <NUM>. In some embodiments, a photodetector <NUM> may be sensitive to emission light <NUM> (e.g., fluorescent light) emitted by the indicator molecules <NUM> such that a signal generated by the photodetector <NUM> in response thereto that is indicative of the level of emission light <NUM> of the indicator molecules <NUM> and, thus, the amount of analyte of interest (e.g., glucose). In some non-limiting embodiments, a photodetector <NUM> may be sensitive to excitation light <NUM> that is reflected from the analyte indicator <NUM> as reflection light <NUM>. In some non-limiting embodiments, one or more of the photodetectors may be covered by one or more filters that allow only a certain subset of wavelengths of light to pass through (e.g., a subset of wavelengths corresponding to emission light <NUM> or a subset of wavelengths corresponding to reflection light <NUM>) and reflect the remaining wavelengths. In some non-limiting embodiments, the temperature transducer <NUM> may output a signal indicative of the temperature inside the housing <NUM> of the sensor <NUM>. In some non-limiting embodiments, the sensor <NUM> may include a drug-eluting polymer matrix that disperses one or more therapeutic agents (e.g., an anti-inflammatory drug).

In some embodiments, the outputs of one or more of the photodetectors <NUM>, <NUM> and the temperature transducer <NUM> may be amplified by an amplifier <NUM>. In some non-limiting embodiments, the amplifier <NUM> may be a comparator that receives analog light measurement signals from the photodetectors <NUM>, <NUM> and output an analog light difference measurement signal indicative of the difference between the received analog light measurement signals. In some non-limiting embodiments, the amplifier <NUM> may be a transimpedance amplifier. However, in some alternative embodiments, a different amplifier may be used. In some embodiments, the outputs of one or more of the photodetectors <NUM>, <NUM>, the temperature transducer <NUM>, and the amplifier <NUM> may be converted to a digital signal by an analog-to-digital converter (ADC) <NUM>.

In some embodiments, one or more of the gain of the amplifier <NUM> and the drive current of the light source <NUM> may be initially set during a quality control process. In some embodiments, one or more of the gain of the amplifier <NUM> and the drive current of the light source <NUM> may be set to allow high dynamic range and to keep the modulated signal within the operational region. In some embodiments, any change (e.g., increase or decrease) to one or more of the drive current of the light source <NUM> and the gain of the amplifier <NUM> may change the modulated signal level accordingly.

In some embodiments, as illustrated in <FIG>, the sensor <NUM> may include a substrate <NUM>. In some embodiments, the substrate <NUM> may be a circuit board (e.g., a printed circuit board (PCB) or flexible PCB) on which circuit components (e.g., analog and/or digital circuit components) may be mounted or otherwise attached. However, in some alternative embodiments, the substrate <NUM> may be a semiconductor substrate having circuitry fabricated therein. The circuitry may include analog and/or digital circuitry. Also, in some semiconductor substrate embodiments, in addition to the circuitry fabricated in the semiconductor substrate, circuitry may be mounted or otherwise attached to the semiconductor substrate <NUM>. In other words, in some semiconductor substrate embodiments, a portion or all of the circuitry, which may include discrete circuit elements, an integrated circuit (e.g., an application specific integrated circuit (ASIC)) and/or other electronic components (e.g., a non-volatile memory), may be fabricated in the semiconductor substrate <NUM> with the remainder of the circuitry is secured to the semiconductor substrate <NUM> and/or a core (e.g., ferrite core) for an inductive element of the transceiver interface <NUM>. In some embodiments, the semiconductor substrate <NUM> and/or a core may provide communication paths between the various secured components.

In some embodiments, one or more of the sensor housing <NUM>, analyte indicator <NUM>, indicator molecules <NUM>, light source <NUM>, photodetectors <NUM>, <NUM>, temperature transducer <NUM>, substrate <NUM>, and transceiver interface <NUM> of sensor <NUM> may include some or all of the features described in one or more of<CIT>, <CIT>, and <CIT>. Similarly, the structure and/or function of the sensor <NUM> and/or transceiver <NUM> may be as described in one or more of <CIT>, <CIT>, and <CIT>.

<FIG> is a schematic view of the transceiver <NUM> according to a non-limiting embodiment. In some embodiments, as shown in <FIG>, the transceiver <NUM> may have a connector <NUM>, such as, for example and without limitation, a Micro-Universal Serial Bus (USB) connector. In some embodiments, the connector <NUM> may enable a wired connection to an external device, such as a personal computer (e.g., personal computer <NUM>) or a display device <NUM> (e.g., a smartphone).

In some embodiments, the transceiver <NUM> may exchange data to and from the external device through the connector <NUM> and/or may receive power through the connector <NUM>. The transceiver <NUM> may include a connector integrated circuit (IC) <NUM>, such as, for example, a USB-IC, which may control transmission and receipt of data through the connector <NUM>. The transceiver <NUM> may also include a charger IC <NUM>, which may receive power via the connector <NUM> and charge or recharge a battery <NUM> (e.g., lithium-polymer battery).

In some embodiments, as shown in <FIG>, the transceiver <NUM> may include one or more connectors in addition to (or as an alternative to) Micro-USB connector <NUM>. For example, in one alternative embodiment, the transceiver <NUM> may include a spring-based connector (e.g., Pogo pin connector) in addition to (or as an alternative to) Micro-USB connector <NUM>, and the transceiver <NUM> may use a connection established via the spring-based connector for wired communication to a personal computer (e.g., personal computer <NUM>) or a display device <NUM> (e.g., a smartphone) and/or to receive power, which may be used, for example, to charge the battery <NUM>.

In some embodiments, as shown in <FIG>, the transceiver <NUM> may have a wireless communication IC <NUM>, which enables wireless communication with an external device, such as, for example, one or more personal computers (e.g., personal computer <NUM>) or one or more display devices <NUM> (e.g., a smartphone). In one non-limiting embodiment, the wireless communication IC <NUM> may employ one or more wireless communication standards to wirelessly transmit data. The wireless communication standard employed may be any suitable wireless communication standard, such as an ANT standard, a Bluetooth standard, or a Bluetooth Low Energy (BLE) standard (e.g., BLE <NUM>). In some non-limiting embodiments, the wireless communication IC <NUM> may be configured to wirelessly transmit data at a frequency greater than <NUM> gigahertz (e.g., <NUM> or <NUM>). In some embodiments, the wireless communication IC <NUM> may include an antenna (e.g., a Bluetooth antenna). In some non-limiting embodiments, the antenna of the wireless communication IC <NUM> may be entirely contained within the housing (e.g., housing <NUM> and <NUM>) of the transceiver <NUM>. However, this is not required, and, in alternative embodiments, all or a portion of the antenna of the wireless communication IC <NUM> may be external to the transceiver housing.

In some embodiments, as shown in <FIG>, the transceiver <NUM> may include a display interface <NUM>, which may enable communication by the transceiver <NUM> with one or more display devices <NUM>. In some embodiments, the display interface <NUM> may include the antenna of the wireless communication IC <NUM> and/or the connector <NUM> illustrated in <FIG>. In some non-limiting embodiments, the display interface <NUM> may additionally include the wireless communication IC <NUM> and/or the connector IC <NUM> illustrated in <FIG>.

In some embodiments, as shown in <FIG>, the transceiver <NUM> may include voltage regulators <NUM> and/or a voltage booster <NUM>. The battery <NUM> may supply power (via voltage booster <NUM>) to radio-frequency identification (RFID) reader IC <NUM>, which may use an inductive element <NUM> to convey information (e.g., commands) to the sensor <NUM> and receive information (e.g., measurement information) from the sensor <NUM>. In some non-limiting embodiments, the sensor <NUM> and transceiver <NUM> may communicate using near field communication (NFC) (e.g., at a frequency of <NUM>). In the illustrated embodiment, the inductive element <NUM> may be include a flat antenna. In some non-limiting embodiments, the antenna may be flexible. However, the inductive element <NUM> of the transceiver <NUM> may be in any configuration that permits adequate field strength to be achieved when brought within adequate physical proximity to an inductive element of the sensor <NUM>. In some embodiments, the transceiver <NUM> may include a power amplifier <NUM> to amplify the signal to be conveyed by the inductive element <NUM> to the sensor <NUM>.

In some embodiments, as shown in <FIG>, the transceiver <NUM> may include a peripheral interface controller (PIC) microcontroller <NUM> and memory <NUM> (e.g., Flash memory), which may be non-volatile and/or capable of being electronically erased and/or rewritten. The PIC microcontroller <NUM> may control the overall operation of the transceiver <NUM>. For example, the PIC microcontroller <NUM> may control the connector IC <NUM> or wireless communication IC <NUM> to transmit data via wired or wireless communication and/or control the RFID reader IC <NUM> to convey data via the inductive element <NUM>. The PIC microcontroller <NUM> may also control processing of data received via the inductive element <NUM>, connector <NUM>, or wireless communication IC <NUM>.

In some embodiments, as shown in <FIG>, the transceiver <NUM> may include a sensor interface <NUM>, which may enable communication between the transceiver <NUM> and sensor <NUM>. In some embodiments, the sensor interface <NUM> may include the inductive element <NUM> illustrated in <FIG>. In some non-limiting embodiments, the sensor interface <NUM> may additionally include the RFID reader IC <NUM> and/or the power amplifier <NUM> illustrated in <FIG>. However, in some alternative embodiments where there exists a wired connection between the sensor <NUM> and the transceiver <NUM> (e.g., transcutaneous embodiments), the sensor interface <NUM> may include the wired connection.

In some embodiments, as shown in <FIG>, the transceiver <NUM> may include a display <NUM> (e.g., liquid crystal display and/or one or more light emitting diodes), which PIC microcontroller <NUM> may control to display data (e.g., analyte levels). In some embodiments, the transceiver <NUM> may include a speaker <NUM> (e.g., a beeper) and/or vibration motor <NUM>, which may be activated, for example, in the event that an alarm condition (e.g., detection of a hypoglycemic or hyperglycemic condition) is met.

In some embodiments, as shown in <FIG>, the transceiver <NUM> may include one or more environmental sensors <NUM>. In some embodiments, the environmental sensors <NUM> may include one or more the posture sensors <NUM>, pressure sensors <NUM>, shock sensors <NUM>, and temperature sensors <NUM> illustrated in <FIG>.

In some embodiments, the transceiver <NUM> may be a body-worn transceiver that is a rechargeable, external device worn over the sensor implantation or insertion site. The transceiver <NUM> may supply power to the proximate sensor <NUM>, calculate analyte levels from data received from the sensor <NUM>, and/or transmit the calculated analyte levels to a display device <NUM> (see <FIG> and <FIG>). Power may be supplied to the sensor <NUM> through an inductive link (e.g., an inductive link of <NUM>). In some embodiments, the transceiver <NUM> may be placed using an adhesive patch or a specially designed strap or belt. The external transceiver <NUM> may read measured analyte data from a subcutaneous sensor <NUM> (e.g., up to a depth of <NUM> or more). The transceiver <NUM> may periodically (e.g., every <NUM>, <NUM>, or <NUM> minutes) read sensor data and calculate an analyte levels and an analyte levels trend. From this information, the transceiver <NUM> may also determine if an alert and/or alarm condition exists, which may be signaled to the user (e.g., through vibration by vibration motor <NUM> and/or an LED of the transceiver's display <NUM> and/or a display <NUM> of a display device <NUM>). The information from the transceiver <NUM> (e.g., calculated analyte levels, calculated analyte levels trends, alerts, alarms, and/or notifications) may be transmitted to a display device <NUM> (e.g., via Bluetooth Low Energy with Advanced Encryption Standard (AES)-Counter CBC-MAC (CCM) encryption) for display by a mobile medical application (MMA) being executed by the display device <NUM>. In some non-limiting embodiments, the MMA may provide alarms, alerts, and/or notifications in addition to any alerts, alarms, and/or notifications received from the transceiver <NUM>. In one embodiment, the MMA may be configured to provide push notifications.

In some embodiments, the transceiver <NUM> of the analyte monitoring system <NUM> may receive one or more sensor measurements indicative of an amount, level, or concentration of an analyte in a first medium (e.g., interstitial fluid ("ISF")) in proximity to the analyte sensor <NUM>. In some embodiments, the transceiver <NUM> may receive the sensor measurements conveyed by the sensor <NUM> periodically (e.g., every <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> minutes). In some embodiments, the one or more sensor measurements may include, for example and without limitation, one or more of (i) one or more measurements indicative of an amount of emission light from indicator molecules of the sensor elements <NUM> (e.g., as measured by one or more photodetectors of the sensor elements <NUM>), (ii) one or more measurements indicative of an amount of reference light (e.g., as measured by one or more photodetector of the sensor elements <NUM>), and (iii) one or more temperature measurements (e.g., as measured by one or more temperature transducers <NUM> of the sensor elements <NUM>). In some embodiments, the transceiver <NUM> may use the received sensor measurements to calculate a first medium analyte level (e.g., an ISF analyte level).

In some embodiments, the transceiver <NUM> may use the calculated first medium analyte level and at least one or more previously calculated first medium analyte levels to calculate a rate of change of the first medium analyte level ("M1_ROC"). In some non-limiting embodiments, to calculate M1_ROC, the transceiver <NUM> may use just the calculated first medium analyte level and the most recent previously calculated first medium analyte level and determine M1_ROC, as the difference between the calculated first medium analyte level and most recent previously calculated first medium analyte level divided by the time difference between a time stamp for the calculated first medium analyte level and a time stamp for the most recent previously calculated first medium analyte level. In some alternative embodiments, to calculate M1_ROC, the transceiver <NUM> may use the calculated first medium analyte level and a plurality of the most recent previously calculated first medium analyte levels. In some non-limiting embodiments, the plurality of the most recent previously calculated first medium analyte levels may be, for example and without limitation, the previous two calculated first medium analyte levels, the previous <NUM> calculated first medium analyte levels, or any number of previously calculated first medium analyte levels in between (e.g., the previous <NUM> calculated first medium analyte levels). In other alternative embodiments, to calculate M1_ROC, the transceiver <NUM> may use the calculated first medium analyte level and the previously calculated first medium analyte levels that were calculated during a time period. In some non-limiting embodiments, the time period may be, for example and without limitation, the last one minute, the last <NUM> minutes, or any amount of time in between (e.g., the last <NUM> minutes). In some embodiments where the transceiver <NUM> uses the calculated first medium analyte level and more than one previously calculated first medium analyte levels to calculate M1_ROC, the transceiver <NUM> may use, for example, linear or non-linear regression to calculate M1_ROC.

In some embodiments, the transceiver <NUM> may convert the calculated first medium analyte level into a second medium analyte level (e.g., a blood analyte level) by performing a lag compensation, which compensates for the time lag between a second medium analyte level and an first medium analyte level (e.g., the time lag between a blood analyte level and an ISF analyte level). In some embodiments, the transceiver <NUM> may calculate the second medium analyte level using at least the calculated first medium analyte level and the calculated M1_ROC. In some non-limiting embodiments, the transceiver <NUM> may calculate the second medium analyte level as M1_ROC/p<NUM> + (<NUM>+p<NUM>/p<NUM>)*M1_analyte, where p<NUM> is analyte diffusion rate, p<NUM> is the analyte consumption rate, and M1_analyte is the calculated first medium analyte level.

In some embodiments, one or more environmental factors may affect the lag between the second medium analyte level and the first medium analyte level. For example and without limitation, one or more environmental factors may affect (i) the user's blood flow in proximity to the sensor <NUM> and/or (ii) the transfer of the analyte from the second medium (e.g., blood) to the first medium (e.g., interstitial fluid) in proximity to the sensor <NUM>. The environmental factors may include, for example and without limitation, a user's posture, pressure on the sensing region, shock to the sensing region, and temperature changes in the sensing region. In some embodiments, the analyte monitoring system <NUM> may use one or more environmental measurements indicative of one or more environmental factors to improve the calculation of second medium analyte levels. In some non-limiting embodiments, the analyte monitoring system <NUM> may use one or more environmental measurements indicative of one or more environmental factors to improve the conversion of a first analyte medium level to second medium analyte level.

In some embodiments, the transceiver <NUM> may use one or more sensor measurements received from the analyte sensor <NUM> and one or more environmental measurements (e.g., one or more environmental measurements generated by the one or more environmental sensors <NUM>) to calculate a second medium analyte level. In some non-limiting embodiments, the transceiver <NUM> may adjust a conversion function used to calculate a second medium analyte level based on one or more environmental measurements generated by the one or more environmental sensors <NUM>. In some non-limiting embodiments, the transceiver <NUM> may adjust the conversion function by adjusting one or more parameters (e.g., one or more of the analyte diffusion rate and analyte consumption rate parameters) of the conversion function. In some non-limiting embodiments, the transceiver <NUM> may adjust one or more of p<NUM> and p<NUM> (or one or more of <NUM>/p<NUM> and p<NUM>/p<NUM>) in the conversion function that calculates a second medium analyte level as M1_ROC/p<NUM> + (<NUM>+p<NUM>/p<NUM>)*M1_analyte. In some alternative embodiments, the transceiver <NUM> may select one of a plurality of conversion functions based on one or more environmental measurements generated by the one or more environmental sensors <NUM>.

In some embodiments, a user's posture (e.g., whether the user is lying down, sitting up, or standing) may affect (i) the user's blood flow in proximity to the sensor <NUM> and/or (ii) the transfer of the analyte from the second medium (e.g., blood) to the first medium (e.g., interstitial fluid) in proximity to the sensor <NUM>. In some embodiments, the transceiver <NUM> may calculate the second medium analyte level (e.g., blood analyte level) using at least one or more sensor measurements received from the analyte sensor <NUM> and one or more posture measurements generated by the posture sensor <NUM>. In some non-limiting embodiments, the transceiver <NUM> may calculate a posture of the user of transceiver <NUM> using the one or more posture measurements generated by the posture sensor <NUM>. In some non-limiting embodiments, the transceiver <NUM> may calculate the second medium analyte level using at least one or more sensor measurements received from the analyte sensor <NUM> and the calculated posture. In some non-limiting embodiments, the transceiver <NUM> may adjust one or more parameters of the conversion function (e.g., the analyte diffusion rate) based on at least the calculated posture and use the adjusted conversion function and the one or more sensor measurements received from the analyte sensor <NUM> to calculate the second medium analyte level. In some non-limiting alternative embodiments, the transceiver <NUM> may select one of a plurality of conversion functions based on the calculated posture and use the selected conversion function and the one or more sensor measurements received from the analyte sensor <NUM> to calculate the second medium analyte level.

In some non-limiting embodiments, the transceiver <NUM> may additionally or alternatively change the sampling frequency of one or more sensors (e.g., the frequency at which one or more posture sensors <NUM>, one or more pressure sensors <NUM>, one or more shock sensors <NUM>, and/or one or more temperature sensors <NUM> generate measurements) based on the calculated posture. In some non-limiting embodiments, based on the calculated posture, the transceiver <NUM> may additionally or alternatively cause one or more of the transceiver <NUM> and the display device <NUM> to display one or more icons indicative of environmental events (e.g., an icon indicative of a posture of the user of the transceiver <NUM>).

In some embodiments, pressure on the user's body in proximity to the sensor <NUM> (e.g., whether the user is lying on the sensor <NUM> or wearing tight clothing around the sensor <NUM>) may affect (i) the user's blood flow in proximity to the sensor <NUM> and/or (ii) the transfer of the analyte from the second medium (e.g., blood) to the first medium (e.g., interstitial fluid) in proximity to the sensor <NUM>. In some embodiments, the transceiver <NUM> may calculate the second medium analyte level (e.g., blood analyte level) using at least one or more sensor measurements received from the analyte sensor <NUM> and one or more pressure measurements generated by the pressure sensor <NUM>. In some non-limiting embodiments, the transceiver <NUM> may adjust one or more parameters of the conversion function (e.g., the analyte diffusion rate) based on at least the one or more pressure measurements and use the adjusted conversion function and the one or more sensor measurements received from the analyte sensor <NUM> to calculate the second medium analyte level. In some non-limiting alternative embodiments, the transceiver <NUM> may select one of a plurality of conversion functions based on the one or more pressure measurements and use the selected conversion function and the one or more sensor measurements received from the analyte sensor <NUM> to calculate the second medium analyte level.

In some non-limiting embodiments, the transceiver <NUM> may additionally or alternatively change the sampling frequency of one or more sensors (e.g., the frequency at which one or more posture sensors <NUM>, one or more pressure sensors <NUM>, one or more shock sensors <NUM>, and/or one or more temperature sensors <NUM> generate measurements) based on the one or more pressure measurements. In some non-limiting embodiments, based on the one or more pressure measurements, the transceiver <NUM> may additionally or alternatively cause one or more of the transceiver <NUM> and the display device <NUM> to display one or more icons indicative of environmental events (e.g., an icon indicative of pressure on the user's body in proximity to the sensor <NUM>).

In some embodiments, bruising and/or blood in proximity to the sensor <NUM> (e.g., due to shocks or impacts to the user's body) may affect (i) the user's blood flow in proximity to the sensor <NUM> and/or (ii) the transfer of the analyte from the second medium (e.g., blood) to the first medium (e.g., interstitial fluid) in proximity to the sensor <NUM>. In some embodiments, the transceiver <NUM> may calculate the second medium analyte level (e.g., blood analyte level) using at least one or more sensor measurements received from the analyte sensor <NUM> and one or more acceleration measurements generated by the shock sensor <NUM>. In some non-limiting embodiments, the transceiver <NUM> may determine whether a shock to the transceiver <NUM> has occurred using the one or more acceleration measurements generated by the shock sensor <NUM>. In some non-limiting embodiments, the transceiver <NUM> may calculate the second medium analyte level using at least one or more sensor measurements received from the analyte sensor <NUM> and the determination of whether a shock to the transceiver <NUM> has occurred. In some non-limiting embodiments, the transceiver <NUM> may adjust one or more parameters of the conversion function (e.g., the analyte diffusion rate) based on at least the shock determination and use the adjusted conversion function and the one or more sensor measurements received from the analyte sensor <NUM> to calculate the second medium analyte level. In some non-limiting alternative embodiments, the transceiver <NUM> may select one of a plurality of conversion functions based on the shock determination and use the selected conversion function and the one or more sensor measurements received from the analyte sensor <NUM> to calculate the second medium analyte level.

In some non-limiting embodiments, the transceiver <NUM> may additionally or alternatively change the sampling frequency of one or more sensors (e.g., the frequency at which one or more posture sensors <NUM>, one or more pressure sensors <NUM>, one or more shock sensors <NUM>, and/or one or more temperature sensors <NUM> generate measurements) based on the shock determination. In some non-limiting embodiments, based on the shock determination, the transceiver <NUM> may additionally or alternatively cause one or more of the transceiver <NUM> and the display device <NUM> to display one or more icons indicative of environmental events (e.g., an icon indicative of a shock or impact to the user's body).

In some non-limiting embodiments, the transceiver <NUM> may additionally or alternatively adjust one or more of the received sensor measurements (e.g., one or more temperature measurements of the received sensor measurements). For example and without limitation, the transceiver <NUM> may adjust one or more temperature measurements of the received sensor measurements. In some embodiments, the temperature measurements may reflect the temperature inside the sensor <NUM> (e.g., the temperature of the substrate <NUM> as measured by the temperature transducer <NUM> of the sensor <NUM>) as opposed to the temperature of the analyte indicator <NUM>, which may be on the exterior of the sensor <NUM>. In some embodiments, the transceiver <NUM> may adjust one or more temperature measurements because, as shown in <FIG>, the temperature inside the sensor <NUM> may lag behind the temperature of the analyte indicator <NUM>.

In some embodiments, as shown in <FIG>, the analyte indicator <NUM> of an implanted sensor <NUM> may be in contact with subcutaneous tissue <NUM>, and interstitial fluid of the subcutaneous tissue <NUM> may permeate the analyte indicator <NUM>. Accordingly, the temperature of the analyte indicator <NUM> may correspond to the temperature of the subcutaneous tissue <NUM> in proximity to the sensor <NUM>. In some non-limiting embodiments, the time lag between the temperature of the analyte indicator <NUM> and the temperature inside the sensor <NUM> (as measured by the temperature transducer <NUM>) may be due to the thermal properties (e.g., thermal conductivity) of the materials of the sensor body. As a result, when the temperature of the analyte indicator <NUM> changes, there may be a delay before the change is reflected in the temperature measurements taken by one or more temperature transducers <NUM> of the sensor elements <NUM> of the analyte sensor <NUM>. In some embodiments, the analyte monitoring system <NUM> (e.g., the transceiver <NUM> of the system <NUM>) may use one or more temperature measurements received from the sensor <NUM> in the calculation of analyte levels (e.g., analyte concentrations). Thus, the lag between the measured temperature and the temperature of the analyte indicator <NUM> may impact negatively the accuracy of the calculated analyte levels.

In some embodiments, the transceiver <NUM> may adjust one or more temperature measurements received from the analyte sensor <NUM> to compensate for the time lag between the measured temperature and the temperature of the analyte indicator <NUM>. In some embodiments, the transceiver <NUM> may adjust one or more received temperature measurements to be estimates of the temperature of the analyte indicator <NUM> instead of measurements of the temperature inside the sensor <NUM>. In some non-limiting embodiments, the transceiver <NUM> may use the adjusted temperature measurements to calculate one or more analyte levels (e.g., one or more first medium analyte levels and/or one or more second medium analyt levels).

In some non-limiting embodiments, the transceiver <NUM> may use a single compartment model to estimate the temperature of the analyte indicator <NUM>. <FIG> and <FIG> illustrate examples of single compartment models for estimating the temperature of the interstitial fluid in the subcutaneous tissue <NUM> in proximity to the analyte indicator <NUM>. With the single compartment model, dTS/dt = TSub/τ- TS/τ, where TSub is the temperature of the subcutaneous tissue <NUM>, TS is the temperature of the sensor <NUM>, τ is the rate constant between the subcutaneous tissue <NUM> and the sensor <NUM>, and dTS/dt is the derivative of the temperature of the sensor <NUM> with respect to time. Based on this equation, TSub = τ * dTS/dt + TS. In some non-limiting embodiments, τ may range, for example and without limitation, from milliseconds to minutes for electronics encasement materials of the sensor <NUM>.

In some embodiments, the transceiver <NUM> may receive a temperature measurement from the sensor <NUM>. In some embodiments, the transceiver <NUM> may calculate a rate of change of the temperature of the sensor <NUM> (Ts_ROC) using at least the received temperature measurement and one or more previous temperature measurements. In some non-limiting embodiments, to calculate Ts_ROC, the transceiver <NUM> may use just the received temperature measurement and the most recent previously received temperature measurement and determine Ts_ROC as the difference between the received temperature measurement and most recent previously received temperature measurement divided by the time difference between a time stamp associated with the received temperature measurement and a time stamp associated with the most recent previously received temperature measurement. In some alternative embodiments, to calculate TS_ROC, the transceiver <NUM> may use the received temperature measurement and a plurality of the most recent previously received temperature measurements. In some non-limiting embodiments, the plurality of the most recent previously received temperature measurements may be, for example and without limitation, the previous two received temperature measurements, the previous <NUM> received temperature measurement, or any number of previously calculated received temperature measurements in between (e.g., the previous <NUM> received temperature measurements). In other alternative embodiments, to calculate TS_ROC, the transceiver <NUM> may use the received temperature measurement and the previous temperature measurements that were received during a time period. In some non-limiting embodiments, the time period may be, for example and without limitation, the last one minute, the last <NUM> minutes, or any amount of time in between (e.g., the last <NUM> minutes). In some embodiments where the transceiver <NUM> uses the received temperature measurement and more than one previously received temperature measurements to calculate TS_ROC, the transceiver <NUM> may use, for example, linear or non-linear regression to calculate TS_ROC.

In some non-limiting embodiments, the transceiver <NUM> may calculate an estimated temperature of the analyte indicator <NUM> using at least the received temperature measurement and the calculated rate of change of the temperature of the sensor <NUM> (TS_ROC). In some embodiments, because interstitial fluid of the subcutaneous tissue <NUM> permeates the analyte indicator <NUM>, the transceiver <NUM> may treat the temperature of the analyte indicator <NUM> as equal to the temperature of the subcutaneous tissue <NUM> (TSub) and calculate the estimated temperature of the analyte indicator <NUM> using the equation above for the temperature of the subcutaneous tissue <NUM> (TSub). In some embodiments, the transceiver <NUM> may use the received temperature measurement and the calculated rate of change of the temperature of the sensor <NUM> (TS_ROC) as the temperature of the sensor <NUM> (TS) and the derivative of the temperature of the sensor <NUM> with respect to time (dTS/dt), respectively, in the equation above for the temperature of the subcutaneous tissue <NUM> (TSub). In some embodiments, the transceiver <NUM> may use the estimated temperature of the analyte indicator <NUM> (instead of the received temperature measurement) to calculate the second medium analyte level (e.g., the blood analyte level). In some non-limiting embodiments, the transceiver <NUM> may use the estimated temperature of the analyte indicator <NUM> (instead of the received temperature measurement) to calculate the first medium analyte level (e.g., the ISF analyte level), which may be used to calculate the second medium analyte level.

In some non-limiting alternative embodiments, the transceiver <NUM> may use a multi-compartment model to estimate the temperature of the analyte indicator <NUM>. <FIG> illustrates an example of a multi-compartment model for estimating the temperature of the interstitial fluid in the subcutaneous tissue <NUM> in proximity to the analyte indicator <NUM>. In some embodiments, as shown in <FIG>, the sensor <NUM> may be implanted in the hypodermis or subcutaneous tissue <NUM>, which is above the core and below the dermis and epidermis.

In some embodiments, the one or more temperature sensors <NUM> of the transceiver <NUM> may detect temperature changes before the one or more temperature transducers <NUM> of the sensor elements <NUM> of the analyte sensor <NUM>. For example and without limitation, if a user gets into an ice bath or a hot tub, the one or more temperature sensors <NUM> of the transceiver <NUM> may detect the resultant temperature change before the one or more temperature transducers <NUM> of the sensor elements <NUM> of the analyte sensor <NUM>. In some embodiments, the transceiver <NUM> may use one or more temperature measurements generated by the one or more temperature sensors <NUM> of the transceiver <NUM> to predict changes in the interstitial fluid in the subcutaneous tissue <NUM> in proximity to the sensor <NUM>. In some embodiments, the transceiver <NUM> may use the one or more temperature measurements generated by the one or more temperature sensors <NUM> of the transceiver <NUM> to adjust one or more temperature measurements generated by the one or more temperature transducers <NUM> of the sensor elements <NUM> of the analyte sensor <NUM>. In some embodiments, the adjustments may account for the lag between (i) temperature changes to the interstitial fluid of the subcutaneous tissue <NUM> that permeates the analyte indicator <NUM> of the sensor <NUM> and (ii) temperature changes in the sensor <NUM>. In some embodiments, the adjusted temperature measurements may reflect the temperature of the analyte indicator <NUM> of the sensor <NUM> more accurately than the unadjusted temperature measurements. In some embodiments, the transceiver <NUM> may use one or more adjusted temperature measurements (instead of the original temperature measurements conveyed by the sensor <NUM>) to calculate the second medium analyte level (e.g., the blood analyte level). In some non-limiting embodiments, the transceiver <NUM> may use one or more adjusted temperature measurements (instead of the original temperature measurements conveyed by the sensor <NUM>) to calculate the first medium analyte level (e.g., the ISF analyte level), which may be used to calculate the second medium analyte level.

In some embodiments, the transceiver <NUM> may receive a temperature measurement conveyed by the sensor <NUM>. In some embodiments, the transceiver <NUM> may calculate a rate of change of the temperature of the sensor <NUM> (TS_ROC) using at least the received temperature measurement and one or more temperature measurements previously received from the sensor <NUM>. In some embodiments, the transceiver <NUM> may calculate a rate of change of the temperature of the transceiver <NUM> (TT_ROC) using at least a temperature measurement generated by a temperature sensor <NUM> (e.g., of the transceiver <NUM>) and one or more temperature measurements previously generated by the temperature sensor <NUM>. In some non-limiting embodiments, TT_ROC may be calculated in a manner similar to any of the manners that may be used to calculate TS_ROC. In some non-limiting embodiments, the transceiver <NUM> may calculate an estimated temperature of the analyte indicator <NUM> using at least the temperature measurement received from the sensor <NUM>, the calculated rate of change of the temperature of the sensor <NUM> (TS_ROC), the temperature measurement generated by a temperature sensor <NUM>, and the calculated rate of change of the temperature of the transceiver <NUM> (TT_ROC). In some embodiments, the transceiver <NUM> may use the estimated temperature of the analyte indicator <NUM> (instead of the temperature measurement received from the sensor <NUM>) to calculate the second medium analyte level (e.g., the blood analyte level). In some non-limiting embodiments, the transceiver <NUM> may use the estimated temperature of the analyte indicator <NUM> (instead of the temperature measurement received from the sensor <NUM>) to calculate the first medium analyte level (e.g., the ISF analyte level), which may be used to calculate the second medium analyte level.

In some non-limiting embodiments, as described above, a single compensation model may be used to compensate for the lag between one or more measured temperatures (e.g., the temperature of the sensor <NUM> as measured by a temperature transducer <NUM> and/or the temperature of the transceiver <NUM> as measured by a temperature sensor <NUM>) and the temperature of the temperature of analyte indicator <NUM>. In some embodiments, a single compensation model may compensate for one medium in the lag compensation model. In some single compensation model embodiments, the temperature may be compensated with single variable temperature estimations. In some non-limiting embodiments, the single variable may be τ (i.e., the rate constant between the subcutaneous tissue <NUM> and the sensor <NUM>). In some non-limiting alternative embodiments, a multi-compensation model may be used to compensate for the lag between one or more measured temperatures (e.g., the temperature of the sensor <NUM> as measured by a temperature transducer <NUM> and/or the temperature of the transceiver <NUM> as measured by a temperature sensor <NUM>) and the temperature of the temperature of analyte indicator <NUM>. In some multi-compensation model embodiments, the temperature may be compensated with multivariable variable temperature estimations. In some embodiments, the multiple variables may be different rate constants for different media through which the compensation is being applied.

In some non-limiting embodiments, the transceiver <NUM> may additionally or alternatively change the sampling frequency of one or more sensors (e.g., the frequency at which one or more posture sensors <NUM>, one or more pressure sensors <NUM>, one or more shock sensors <NUM>, and/or one or more temperature sensors <NUM> generate measurements) based on one or more temperature measurements generated by the one or more temperature sensors <NUM> of the transceiver <NUM> (e.g., based on a rate of temperature change indicated by the temperature measurements). In some non-limiting embodiments, based on one or more temperature measurements generated by the one or more temperature sensors <NUM> of the transceiver <NUM>, the transceiver <NUM> may additionally or alternatively cause one or more of the transceiver <NUM> and the display device <NUM> to display one or more icons indicative of environmental events (e.g., an icon indicative of a temperature change if the temperature measurements indicate a rate of temperature change greater than a threshold).

In some embodiments, the transceiver <NUM> may receive temperature measurements more frequently than the transceiver <NUM> receives analyte measurements (e.g., light measurements). In some non-limiting embodiments, the more frequent temperature measurements may enable the transceiver <NUM> to calculate more accurate rates of temperature change (e.g., TS_ROC and TT_ROC). In some non-limiting embodiments, the transceiver <NUM> may convey analyte measurement and temperature measurement commands to the sensor <NUM>. In response to an analyte measurement command, the sensor <NUM> may convey sensor data including one or more light measurements and one or more temperature measurements to the transceiver <NUM>. In response to a temperature measurement commands, the sensor <NUM> may convey sensor data including one or more temperature measurements (and no light measurements) to the transceiver <NUM>. In some non-limiting embodiments, the sensor <NUM> may not activate the light source <NUM> during execution of a temperature measurement command.

In some non-limiting embodiments, the transceiver <NUM> may change the sampling frequency of one or more temperature sensors (e.g., the sample frequency of one or more temperature transducers <NUM> and/or one or more temperature sensors <NUM>). In some non-limiting embodiments, the transceiver <NUM> may change the sampling frequency of one or more temperature sensors, for example and without limitation, when analyte level is rising or falling at a fast rate and/or when the analyte level is in or approaching a hypo- or hyperglycemic range. In some non-limiting embodiments, the estimation of the temperature of the analyte indicator <NUM> may be applied to different temperature sampling rates.

<FIG> is a flow chart illustrating a process <NUM> for calculating second medium analyte levels (e.g., blood analyte levels). In some embodiments, one or more steps of the process <NUM> may be performed by an analyte monitoring system, such as, for example, the analyte monitoring system <NUM>. In some embodiments, one or more steps of the process <NUM> may be performed by a transceiver, such as, for example, the transceiver <NUM>. In some non-limiting embodiments, one or more steps of the process <NUM> may be performed by a processor, such as, for example, the PIC microcontroller <NUM> of the transceiver <NUM>.

In some embodiments, the process <NUM> may include a step <NUM> in which the transceiver <NUM> receives one or more sensor measurements conveyed by the sensor <NUM>. In some non-limiting embodiments, the one or more sensor measurements may include, for example and without limitation, one or more light measurements and/or one or more temperature measurements. In some embodiments, the transceiver <NUM> may receive the one or more sensor measurements after conveying a command (e.g., a measurement command or a read sensor data command) to the sensor <NUM>. However, this is not required, and, in some alternative embodiments, the sensor <NUM> may control when one or more sensor measurements are conveyed to the transceiver <NUM>, or the sensor <NUM> may continuously convey sensor measurements to the transceiver <NUM>. In some non-limiting embodiments, the transceiver <NUM> may receive one or more sensor measurements periodically (e.g., every <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> minutes).

In some embodiments, the transceiver <NUM> may receive the one or more sensor measurements using the sensor interface device <NUM> of the transceiver <NUM>. In some non-limiting embodiments, the transceiver <NUM> may receive the one or more sensor measurements wirelessly. For example and without limitation, in some non-limiting embodiments, the transceiver <NUM> may receive the one or more sensor measurements by detecting modulations in an electromagnetic wave generated by the sensor <NUM>, e.g., by detecting modulations in the current flowing through the inductive element <NUM> of the transceiver <NUM>. However, this is not required, and, in some alternative embodiments, the transceiver <NUM> may receive the sensor data via a wired connection to the sensor <NUM>.

In some embodiments, the one or more sensor measurements may be associated with a time stamp. In some non-limiting embodiments, the transceiver <NUM> may receive the time stamp from the sensor <NUM>. In some non-limiting embodiments, the received one or more sensor measurements may include the time stamp. In some embodiments, the time stamp may reflect the time at which the one or more sensor measurements were taken. However, it is not required that the transceiver <NUM> receive the time stamp from the sensor <NUM>. For example, in some alternative embodiments, the transceiver <NUM> may assign the time stamp to the one or more sensor measurements after receiving the one or more sensor measurements. In these embodiments, the time stamp may reflect when the transceiver <NUM> received the one or more sensor measurements.

In some embodiments, the process <NUM> may include a step <NUM> in which the transceiver <NUM> receives or generates one or more environmental measurements. In some embodiments, the one or more environmental measurements may include one or more one or more posture measurements indicative of the posture of a user of the transceiver <NUM>, one or more pressure measurements indicative of pressure on the transceiver <NUM>, one or more acceleration measurements indicative of whether a shock to the transceiver <NUM> has occurred, and/or one or more temperature measurements indicative of the temperature of the transceiver <NUM>. In some non-limiting embodiments, the one or more environmental sensors <NUM> of the transceiver <NUM> may generate the one or more environmental measurements. In some non-limiting embodiments, the one or more environmental sensors <NUM> may include one or more posture sensors <NUM>, one or more pressure sensors <NUM>, one or more shock sensors <NUM>, and/or one or more temperature sensors <NUM>. In some non-limiting embodiments, the transceiver <NUM> may additionally or alternatively receive one or more of the environmental measurements from a device external to the transceiver <NUM> (e.g., the display device <NUM>).

In some embodiments, the process <NUM> may include a step <NUM> in which the transceiver <NUM> adjusts one or more sensor measurements received from the sensor <NUM>. For example, in some embodiments, the one or more sensor measurements may include one or more temperature measurements, and step <NUM> may include adjusting one or more temperature measurements from the sensor <NUM>. In some embodiments, a temperature measurement may be adjusted to be an estimate of the temperature of the analyte indicator <NUM>, and the estimate may compensate for temperature lag. In some embodiments, adjusting a temperature measurement received from the sensor <NUM> may include calculating a rate of change of the temperature of the sensor <NUM> (TS_ROC) and calculating an adjusted temperature based on one or more of the received temperature measurement and the calculated TS_ROC.

In some non-limiting embodiments, the transceiver <NUM> may adjust one or more sensor measurements based on one or more environmental measurements. For example, in some embodiments, the one or more sensor measurements may include one or more temperature measurements, and step <NUM> may include adjusting one or more temperature measurements from the sensor <NUM> based on at least one or temperature measurements of the one or more environmental measurements (e.g., one or more temperature measurements generated by the one or more temperature sensors <NUM> of the transceiver <NUM>). In some embodiments, a temperature measurement may be adjusted to be an estimate of the temperature of the analyte indicator <NUM>, and the estimate may compensate for temperature lag. In some embodiments, adjusting a temperature measurement received from the sensor <NUM> may include calculating a rate of change of the temperature of the sensor <NUM> (TS_ROC), calculating a rate of change of the temperature of the transceiver <NUM> (TT_ROC), and calculating an adjusted temperature based one or more of a temperature measurement received from the sensor <NUM>, the calculated TS_ROC, a temperature measurement generated by a temperature sensor <NUM>, and the calculated TT_ROC.

In some embodiments, the process <NUM> may include a step <NUM> in which the transceiver <NUM> calculates first medium analyte level (e.g., an ISF analyte level) using the one or more sensor measurements received from the sensor <NUM>. In some embodiments, one or more of the sensor measurements used to calculate the first medium analyte level may have been adjusted in step <NUM>. In some embodiments, the first medium analyte level may be a measurement of the amount or concentration of the analyte in the first medium (e.g., interstitial fluid) in proximity to the analyte sensor <NUM>. In some non-limiting embodiments, calculation of the first medium analyte level may include, for example and without limitation, some or all of the features described in <CIT>, now <CIT>.

In some embodiments, the process <NUM> may include a step <NUM> in which the transceiver <NUM> calculates a first medium analyte level rate of change ("M1_ROC"). In some embodiments, the transceiver <NUM> may calculate the M1_ROC using at least the first medium analyte level calculated in step <NUM> and one or more previously calculated first medium analyte levels (e.g., one or more first medium analyte levels calculated using previously received sensor measurements).

In some embodiments, the process <NUM> may include a step <NUM> in which the transceiver <NUM> adjusts a conversion function used to calculate a second medium analyte level (e.g., a blood analyte level) based on one or more environmental measurements generated by the one or more environmental sensors <NUM>. In some non-limiting embodiments, the transceiver <NUM> may adjust the conversion function by adjusting one or more parameters (e.g., one or more of the analyte diffusion rate and analyte consumption rate parameters) of the conversion function. In some alternative embodiments, in step <NUM>, the transceiver <NUM> may select one of a plurality of conversion functions based on one or more environmental measurements (e.g., one or more environmental measurements generated by the one or more environmental sensors <NUM>).

In some embodiments, the process <NUM> may include a step <NUM> in which the transceiver <NUM> calculates a second medium analyte level (e.g., a blood analyte level). In some embodiments, the transceiver <NUM> may calculate the second medium analyte level by performing a lag compensation. In some embodiments, the transceiver <NUM> may calculate the second medium analyte level using at least the first medium analyte level and the M1_ROC calculated in steps <NUM> and <NUM>, respectively. In some embodiments, the transceiver <NUM> may calculate the second medium analyte level using a conversion function. In some non-limiting embodiments, the conversion function used in step <NUM> may have been adjusted (or selected) in step <NUM>.

In some non-limiting embodiments, the process <NUM> may include a step <NUM> of displaying the calculated second medium analyte level. In some embodiments, the step <NUM> may include displaying the calculated second medium analyte level on a display of the transceiver <NUM>. In some embodiments, the step <NUM> may additionally or alternatively include the transceiver <NUM> conveying the calculated second medium analyte level to a display device (e.g., display device <NUM>) for display. In some non-limiting embodiments, the transceiver <NUM> may convey the calculated second medium analyte level to the display device <NUM> via wired or wireless communication using the display interface device <NUM>. In some embodiments, the display device <NUM> may be configured to receive and display the conveyed second medium analyte level.

Claim 1:
An analyte monitoring system (<NUM>) comprising:
an analyte sensor (<NUM>) comprising:
(i) one or more sensors (<NUM>) configured to generate sensor measurements indicative of an analyte level in a first medium, wherein the sensors include a temperature transducer (<NUM>) configured to generate a sensor temperature measurement, and the sensor measurements include the sensor temperature measurement,
(ii) a housing (<NUM>), wherein the sensor temperature measurement is a measurement of temperature inside the housing of the analyte sensor;
(iii) an analyte indicator (<NUM>) on or in at least a portion of an exterior surface of the housing; and
(iii) a transceiver interface (<NUM>) configured to convey the sensor measurements; and
a transceiver (<NUM>) comprising: (i) a sensor interface (<NUM>) configured to receive the sensor measurements conveyed by the analyte sensor, and (ii) a processor (<NUM>) configured to:
adjust the sensor temperature measurement, wherein the adjusted sensor temperature measurement is an estimate of a temperature of the analyte indicator, the adjusted sensor temperature measurement accounts for a lag between the temperature inside the housing of the analyte sensor and the temperature of the analyte indicator, and adjusting the sensor temperature measurement comprises:
calculating a rate of change of the temperature of the analyte sensor using at least the sensor temperature measurement and one or more sensor temperature measurements received previously from the analyte sensor; and
calculating the adjusted sensor temperature measurement using at least the sensor temperature measurement and the calculated rate of change of the temperature of the analyte sensor; and
calculate an analyte level in a second medium using at least the adjusted sensor temperature measurement and one or more of the sensor measurements.