US20150257687A1 - System for monitoring body chemistry - Google Patents

Abstract

A system and method for monitoring body chemistry of a user, the system comprising: a housing supporting: a microsensor comprising a first and second working electrode, a reference electrode, and a counter electrode, and configured to access interstitial fluid of the user, and an electronics subsystem comprising a signal conditioning module that receives a signal stream, from the microsensor, wherein the electronics subsystem is configured to detect an impedance signal derived from two of the first working electrode, the second working electrode, the reference electrode, and the counter electrode; and a processing subsystem comprising: a first module configured to generate an analysis indicative of an analyte parameter of the user and derived from the signal stream and the impedance signal, and a second module configured to transmit information derived from the analysis to the user, thereby facilitating monitoring of body chemistry of the user.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application claims the benefit of U.S. Provisional Application Ser. No. 61/952,594, filed on 13 Mar. 2014, U.S. Provisional Application Ser. No. 62/012,874, filed on 16 Jun. 2014, and U.S. Provisional Application Ser. No. 62/025,174, filed on 16 Jul. 2014, which are each incorporated herein in its entirety by this reference.
TECHNICAL FIELD
• This invention relates generally to the biometric device field, and more specifically to a new and useful system for monitoring body chemistry in the biometric device field.
BACKGROUND
• Biomonitoring devices are commonly used, particularly by health-conscious individuals and individuals diagnosed with ailments, to monitor body chemistry. Such biomonitoring devices perform the tasks of determining an analyte level in a user's body, and providing information regarding the analyte level to a user; however, these current biomonitoring devices typically convey information to users that is limited in detail, intermittent, and prompted by the command of the user. Such biomonitoring devices, including blood glucose meters, are also inappropriate for many applications outside of intermittent use, and place significant burdens on users (e.g., in requiring finger sticks, in requiring lancing, etc.) due to design and manufacture considerations. Additionally, current devices are configured to analyze one or a limited number of analytes contributing to overall body chemistry, due to limitations of sensors used in current biomonitoring devices.
• There is thus a need in the biometric device field to create a new and useful system for monitoring body chemistry. This invention provides such a new and useful system.
BRIEF DESCRIPTION OF THE FIGURES
• FIG. 1 depicts elements of an embodiment of a system for monitoring body chemistry;
• FIGS. 2A and 2B depict embodiments of a microsensor patch, a transmitting unit, a housing, and an array of filaments in an embodiment of a system for monitoring body chemistry;
• FIG. 2C depict a variation of electrodes in an embodiment of a system for monitoring body chemistry;
• FIGS. 3A-3H depict examples of filament variations in an embodiment of a system for monitoring body chemistry;
• FIG. 4 depicts an embodiment of an electronics subsystem in an embodiment of a system for monitoring body chemistry;
• FIGS. 5A-5C depict examples of a portion of an electronics subsystem in an embodiment of a system for monitoring body chemistry;
• FIGS. 6A-6B depict examples of power management modules in an embodiment of a system for monitoring body chemistry;
• FIG. 7 depicts a variation of an impedance detection module in an embodiment of a system for monitoring body chemistry;
• FIG. 8 depicts an example of an applied voltage waveform in an embodiment of a system for monitoring body chemistry;
• FIG. 9 depicts a variation of a housing in an embodiment of a system for monitoring body chemistry;
• FIGS. 10A-10B depict specific examples of a housing in an embodiment of a system for monitoring body chemistry;
• FIG. 10C depicts a specific portion of a housing in an embodiment of a system for monitoring body chemistry;
• FIGS. 11A-11B depict examples of user interfaces implemented using a software module in an embodiment of a system for monitoring body chemistry;
• FIG. 12A depicts a notification module of an embodiment of a system for monitoring body chemistry;
• FIGS. 12B-12C depict specific examples of notifications in an embodiment of a system for monitoring body chemistry;
• FIG. 13 depicts communication between a processing subsystem and a storage module in an embodiment of a system for monitoring body chemistry;
• FIGS. 14A-14C depict examples of an arch application method and an end-to-end application method, respectively, in an embodiment of a system for monitoring body chemistry;
• FIGS. 15A-15B depict variations of a patch applicator in an embodiment of a system for monitoring body chemistry;
• FIGS. 16A-16D depict a first specific example of a patch applicator in an embodiment of a system for monitoring body chemistry;
• FIG. 17 depicts a second specific example of a patch applicator in an embodiment of a system for monitoring body chemistry;
• FIGS. 18A-18B depict a specific example of a base station in an embodiment of a system for monitoring body chemistry;
• FIG. 19 depicts operation modes of components of an embodiment of a system for monitoring body chemistry; and
• FIG. 20 depicts an embodiment of a method for monitoring body chemistry.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
• The following description of the preferred embodiments of the invention is not intended to limit the invention to these preferred embodiments, but rather to enable any person skilled in the art to make and use this invention.
1. System
• As shown inFIG. 1, an embodiment of thesystem100 for monitoring body chemistry of a user comprises ahousing190 that supports amicrosensor116 and anelectronics subsystem120 in communication with themicrosensor116; and aprocessing subsystem160 configured to generate an analysis indicative of an analyte parameter of the user, wherein the analysis is derived from a signal stream of the microsensor and an impedance signal from the electronics subsystem. In more detail, thehousing190,microsensor116, and theelectronics subsystem120 can be configured as amicrosensor patch110 configured to sense analyte levels in a user's body, wherein the electronics subsystem includes asignal conditioning module122, apower management module124, astorage module127, and a transmittingunit130 in communication with theprocessing subsystem160 and/or an electronic device (e.g., mobile computing device150) associated with the user.
• In some variations, thesystem100 can further include apatch applicator180 configured to facilitate application of themicrosensor patch110 onto the body of a user in a reliable manner. Thesystem100 functions to provide continuous monitoring of a user's body chemistry through reception and processing of signals associated with one or more analytes present in the body of the user, and to provide an analysis of the user's body chemistry to the user and/or an entity (e.g., health care professional, caretaker, relative, friend, acquaintance, etc.) associated with the user. Alternatively, thesystem100 can function to detect a user's body chemistry upon the user's request or sporadically, and/or can provide an analysis of the user's body chemistry only to the user.
• Thesystem100 is configured to be worn by the patient outside of a clinical (e.g., hospital) or research (e.g., laboratory) setting, such that the patient can be in a non-contrived environment as he or she is interfacing with the microsensor patch no for monitoring of body chemistry. Furthermore, elements of thesystem100 can be reusable or disposable (e.g., based upon modularity of the system100), or theentire system100 can be configured to be disposable. In one specific example, thesystem100 adheres to the patient (thus not compelling the patient to hold any part of thesystem100 by hand), has a low profile that conforms to the patient, and is configured to receive and transmit signals indicative of body chemistry parameters of the user, for downstream analysis and information transfer to the user. Alternatively, thesystem100 can be substantially non-portable, non-wearable, and/or intended for use in a clinical or research setting.
• As indicated above and further below, elements of the system can be implemented on one or more computer networks, computer systems, or applications servers, etc. The computer system(s) can comprise one or more of: a cloud-based computer, a mainframe computer system, a grid-computer system, or any other suitable computer system, and the computer system can support collection of data from a wearable device and/or a base station, processing of these data, and transmission of alerts, notifications, and/or user interface updates to one or more electronic computing devices (e.g., mobile computing device, wrist-borne mobile computing device, head-mounted mobile computing device, etc.) linked to or affiliated with an account of the user. For example, the computer system can receive signals indicative of one or more analyte parameters of the user and distribute alerts and notifications over a distributed network, such as over a cellular network or over an Internet connection. In this example, the computer system can upload alerts and notifications to a native body chemistry monitoring application including the user interface and executing on a mobile computing device associated with the user.
• Additionally or alternatively, an electronic computing device (e.g., a laptop computer, a desktop computer, a tablet, a smartphone, a smart watch, a smart eyewear accessory, a personal data assistant, etc.) associated with the system (e.g., with the account of the user) can maintain the account of the user, create and maintain a user-specific model within the account, and execute a native body chemistry monitoring application (including the user interface) with functions including one or more of: generating alerts or notifications, receiving alerts or notifications, displaying alerts or notifications, updating predictions of changes in state of the user, and any other suitable function that enhances body chemistry monitoring of the user. Thesystem100 is preferably configured to implement at least a portion of themethod200 described inSection 2 below; however, thesystem100 can additionally or alternatively be configured to implement any other suitable method.
1.1 System—Microsensor Patch
• As shown inFIG. 1, themicrosensor patch110 comprises amicrosensor116 and anelectronics subsystem120 in communication with themicrosensor116, wherein themicrosensor116 and theelectronics subsystem120 are supported by ahousing190. Themicrosensor patch110 can be configured to detect and sense only a single analyte; however, the microsensor patch no can alternatively be configured to detect and sense multiple analytes in order to provide an analysis based on multiple analytes. Preferably, themicrosensor patch110 is configured to be disposable; however, the microsensor patch no can alternatively be configured to be reusable for any suitable duration or number of uses. In one variation, the microsensor patch no is configured to be a semi-permanent component (e.g., wearable for a week before replacement, wearable for a month before replacement, etc.) configured to sense the user's body chemistry with minimal signal degradation for at a least a week post-coupling of the microsensor patch no to the body of the user. However, in another variation, the microsensor patch no can be configured to be a permanent component configured to permanently couple to a user. Modularity of themicrosensor patch110 is described in further detail below.
1.1.1 System—Microsensor
• Themicrosensor116 of the microsensor patch no preferably comprises an array offilaments117, as shown inFIGS. 1 and 2A, and functions to penetrate skin of the user in order to sense one or more analytes characterizing the user's body chemistry. Preferably, the array offilaments117 is configured to penetrate the user's stratum corneum (i.e., an outer skin layer) in order to sense analytes within interstitial (extracellular) fluid, which is throughout the body; however, the array offilaments117 can be configured to penetrate the user's skin to any other suitable depth. For instance, themicrosensor116 can alternatively be configured to penetrate deeper layers, or various depth layers of a user's skin in order to sense analytes within any appropriate bodily fluid of the user. Themicrosensor116 can be configured to sense analytes/ions characterizing a user's body chemistry using a potentiometric measurement (e.g., for small analytes including potassium, sodium calcium, etc.), using an amperometric measurement (e.g., for large analytes including glucose, lactic acid, creatinine, etc.), using a conductometric measurement, and/or using any other suitable measurement.
• Preferably, sensed analytes result in a signal (e.g., voltage, current, resistance, capacitance, impedance, gravimetric, etc.) detectable by theelectronics subsystem120 in communication with themicrosensor116; however, analyte sensing can comprise any other appropriate mechanism using themicrosensor116. As mentioned earlier, themicrosensor116 is also preferably integrated with theelectronics subsystem120. In a first variation, themicrosensor116 is coupled to the semiconductor architecture of the electronics subsystem120 (e.g., themicrosensor116 is coupled to an integrated circuit comprising the electronics subsystem120), in a second variation, themicrosensor116 is more closely integrated into the semiconductor architecture of the electronics subsystem120 (e.g., there is closer integration between the microsensor116 and an integrated circuit including the electronics subsystem120), and in a third variation, themicrosensor116 and theelectronics subsystem120 are constructed in a system-on-a-chip fashion (e.g., all components are integrated into a single chip). As such, in some variations, filaments the array offilaments117 of themicrosensor116 can be directly or indirectly integrated with electronics components, such that preprocessing of a signal from themicrosensor116 can be performed using the electronics components (e.g., of the array offilaments117, of the electronics subsystem120) prior to or after transmitting signals to the electronics subsystem120 (e.g., to an analog front end, to an analog to digital converter). The electronics components can be coupled to a filament substrate, or otherwise integrated with the filaments in any suitable fashion (e.g., wired, using a contact pad, etc.). Alternatively, the electronics components can be fully integrated into theelectronics subsystem120 and configured to communicate with themicrosensor116, or the electronics components can be split between the microsensor and theelectronics subsystem120. Themicrosensor116 can, however, comprise any other suitable architecture or configuration.
• Themicrosensor116 preferably senses analyte parameters using the array offilaments117, such that absolute values of specific analytes/ions can be detected and analyzed. Themicrosensor116 can additionally be configured to sense analyte parameters using the array offilaments117, such that changes in values of specific analyte/ion parameters or derivatives thereof (e.g., trends in values of a parameter, slopes of curves characterizing a trend in a parameter vs. another parameter, areas under curves characterizing a trend, a duration of time spent within a certain parameter range, etc.) can be detected and analyzed. In one variation, sensing by themicrosensor116 is achieved at a low frequency at discrete time points (e.g., every minute, or every hour), and in another variation, sensing by themicrosensor116 is achieved substantially continuously at a high frequency (e.g., every picosecond, every millisecond, every second). In one specific example for blood chemistry analysis, the array offilaments117 of themicrosensor116 is configured to sense one or more of: electrolytes, glucose, bicarbonate, creatinine, body urea nitrogen (BUN), sodium, iodide, iodine and potassium of a user's blood chemistry. In another specific example, the array offilaments117 of themicrosensor116 is configured to sense at least one of biomarkers, cell count, hormone levels, alcohol content, gases (e.g. carbon dioxide, oxygen, etc.), drug concentrations/metabolism, pH and analytes within a user's body fluid.
• As shown inFIG. 2A, the array offilaments117 is preferably located at the base surface of themicrosensor patch110, and functions to interface directly with a user in a transdermal manner (e.g., in accessing interstitial fluid) in order to sense at least one analyte/ion characterizing the user's body chemistry. The array offilaments117 is preferably arranged in a uniform pattern with a specified density optimized to effectively penetrate a user's skin and provide an appropriate signal, while minimizing pain to the user. Additionally, the array offilaments117 can be arranged in a manner to optimize coupling to the user, such that the microsensor firmly couples to the user over the lifetime usage of the system. For example, thefilaments118 can comprise several pieces and/or be attached to a flexible base to allow the array offilaments117 to conform to a user's body. In one variation, the array offilaments117 is arranged in a rectangular pattern, and in another variation, the array offilaments117 is arranged in a circular or ellipsoid pattern. However, in other variations, the array offilaments117 can be arranged in any other suitable manner (e.g., a random arrangement). The array offilaments117 can also be configured to facilitate coupling to a user, by comprising filaments of different lengths or geometries. Havingfilaments118 of different lengths can further function to allow measurement of different ions/analytes at different depths of penetration (e.g., a filament with a first length can sense one analyte at a first depth, and a filament with a second length can sense another analyte at a second depth). The array offilaments117 can also comprisefilaments118 of different geometries (e.g., height, diameter) to facilitate sensing of analytes/ions at lower or higher concentrations. In one specific example, the array offilaments117 is arranged at a density of 100 filaments per square centimeter and eachfilament118 in the array offilaments117 has a length of 250-350 microns, which allows appropriate levels of detection, coupling to a user, and pain experienced by the user.
• Eachfilament118 in the array offilaments117 preferably functions to sense a single analyte; however, eachfilament118 in the array offilaments117 can additionally be configured to sense more than one analyte. Furthermore, the array offilaments117 can be further configured, such that a subarray of the array offilaments117 functions as a single sensor configured to sense a particular analyte or biomarker, as shown inFIG. 2B. Furthermore, any configuration of subarrays of the array offilaments117 can additionally or alternatively be configured as one or more of: a working electrode, a counter electrode (i.e., auxiliary electrode), and a reference electrode, for instance, in a two-electrode cell, a three-electrode cell, or a more-than-three-electrode cell. In one variation, as shown inFIG. 2C, the array offilaments117 of themicrosensor116 is configured as a first working electrode11 (corresponding to a first subarray of filaments), a second working electrode12 (corresponding to a second subarray of filaments), a counter electrode13 (corresponding to a third subarray of filaments), and a reference electrode14 (corresponding to a fourth subarray of filaments). In a specific example of this variation, each subarray associated with the first workingelectrode11, the second workingelectrode12, thecounter electrode13, and thereference electrode14, respectively, is substantially identical in morphology (e.g., area of the microsensor). Furthermore, in the specific example, each subarray has a square footprint, and the subarrays are configured in a 2×2 arrangement to define a larger square footprint. However, the array offilaments117 can be configured as one or more of: a working electrode, a counter electrode, and a reference electrode in any other suitable manner, and can furthermore have any other suitable morphology(ies) and/or configuration relative to each other.
• Additionally or alternatively, any subarray of the array offilaments117 can be configured to release biomaterials (e.g., therapeutic substances, drugs) for treating a medical condition of a user (e.g., as facilitated by biomaterial dissolution in interstitial fluid). Multiple subarrays of the array of filaments can then be configured to sense different analytes/biomarkers, or the same analyte/biomarker. Furthermore, a subarray or asingle filament118 of the array offilaments117 can be configured as a ground region of themicrosensor116, such that signals generated by themicrosensor116 in response to analyte detection can be normalized by the signals generated by the subarray orsingle filament118 serving as a ground region. Preferably, all subarrays of the array offilaments117 are substantially equal in size and density; however, each subarray of the array offilaments117 can alternatively be optimized to maximize signal generation and detection in response to a specific analyte. In an example, analytes that are known to have a lower concentration within a user's body fluid can correspond to a larger subarray of the array offilaments117. In another example, analytes that are known to have a higher concentration within a user's body fluid can correspond to a smaller subarray of the array offilaments117. In one extreme example, an entire array of filaments can be configured to sense a single analyte, such that themicrosensor116 and microsensor patch no is configured to sense and detect only one analyte. In another extreme example, each single filament in an array can be configured to detect a single analyte allowing for detection of multiple analytes within a single array (e.g., for a 100-filament array, 100 analytes can be tested).
• In other variations, a subarray of the array offilaments117 can also be used to detect other physiologically relevant parameters, such as electrophysiological signals (e.g., electrocardiogram, electroencephalogram), body temperature, respiration, and skin impedance change (e.g., to measure hydration state or inflammatory response). In these other variations, the subarray can be dedicated to measuring these physiologically relevant parameters, which could be combined with analyte/ion parameter measurements in order to provide meaningful information to a user. As an example, the simultaneous measurement of potassium levels and electrocardiogram measurements, enabled by subarrays of the array offilaments117, can provide a more complete diagnosis of cardiovascular problems or events than either measurement by itself.
• A filament118 of the array of filaments can comprise one or more of: a substrate core, the substrate core including a base end coupled to the substrate, a columnar protrusion having a proximal portion coupled to the base end and a distal portion, and a tip region coupled to the distal portion of the columnar protrusion and that facilitates access to the body fluid of the user; a conductive layer, isolated to the tip region of the substrate core and isolated away from the base end and the columnar protrusion as an active region that enables transmission of electronic signals generated upon detection of an analyte; an insulating layer ensheathing the columnar protrusion and base end of the substrate core and exposing a portion of the conductive layer, thereby defining a boundary of the active region; a sensing layer, in communication with the active region, characterized by reversible redox behavior for transduction of an ionic concentration of the analyte into an electronic signal; an intermediate selective layer superficial to the conductive layer and deeper than the sensing layer, relative to a most distal point of the tip region of the filament, that facilitates detection of the analyte; an intermediate protective layer, superficial to the intermediate selective layer, including a functional compound that promotes generation of a protective barrier; and a selective coating superficial to the intermediate protective layer, having a distribution of molecules that respond to presence of the analyte, superficial to the sensing layer. Thus, a filament can comprise one or more regions, morphologies (examples of which are shown inFIGS. 3A-3H, withelements118a-118h), compositions, and/or configurations as described in U.S. Pub. No. 2014/0275897, entitled “On-Body Microsensor for Biomonitoring” and filed on 14 Mar. 2014 and/or U.S. App. No. 62/025,174, and entitled “System for Monitoring Body Chemistry” and filed on 16 Jul. 2014, which are each incorporated herein in their entirety by this reference. However, the filament can additionally or alternatively comprise any other suitable region, composition, morphology, and/or configuration.
1.1.2 System—Electronics Subsystem
• The electronics subsystem120 functions to receive analog signals from themicrosensor116 and to convert them into digital signals to be processed by amicroprocessor113 of theelectronics subsystem120. In receiving signals, processing signals, regulating function, storing data, and/or transmitting data, theelectronics subsystem120 preferably includes amicroprocessor113 interfacing with one or more of: asignal conditioning module122, apower management module124, animpedance detection module126, astorage module127, and a transmittingunit130, as shown inFIG. 4. However, theelectronics subsystem120 can additionally or alternatively include any other suitable modules configured to facilitate signal reception, signal processing, and data transfer in an efficient manner.
• Themicroprocessor113 preferably includes memory and/or is coupled to a storage module127 (e.g., flash storage). Themicroprocessor113 can also include and/or be coupled to a clock/watchdog module (which can be incorporated into a microcontroller unit) for control of timing between different functions of theelectronics subsystem120. Themicroprocessor113 functions to process received signals, enable power distribution, enable impedance monitoring, and enable data transmission from theelectronics subsystem120, in relation to other portions of theelectronics subsystem120 described below; however, themicroprocessor113 can alternatively or additionally be configured to perform any other suitable function.
• Thesignal conditioning module122 functions to preprocess signals detected and received using themicrosensor116, thereby producing conditioned data prior to processing at theprocessing subsystem160. Thesignal conditioning module122 can include one or more of: a signal multiplexer, an analog front end, an amplifier (e.g., a variable gain amplifier), a filter (e.g., low pass filter, high pass filter, band pass filter, etc.), an analog-to-digital converter (ADC), and a digital-to-analog converter (DAC). In one variation, as shown inFIG. 4, thesignal conditioning module122 comprises amultiplexer22 in communication with themicrosensor116, wherein themultiplexer22 is configured to communicate an output to an analogfront end23 that interfaces themicrosensor116 with anADC24 by way of avariable gain amplifier25 coupled to afilter26. In a specific example of this variation, the analogfront end23 circuitry is configured with a shifted potential different than a reference potential of thereference electrode14 of themicrosensor116, wherein the shifted potential is different (e.g., −2V to 2V different) from the reference potential of thereference electrode14. The configuration involving a difference between the shifted potential and the reference potential can allow thesystem100 to drive redox reactions at the surface of themicrosensor110. However, in alternative variations of the specific example, the analog front end (or any other element of the signal conditioning module122) can be configured with any other suitable potential relative to potentials of electrodes of themicrosensor116.
• In more detail, themultiplexer22 of thesignal conditioning module122 is preferably configured to receive multiple signals from the microsensor116 (e.g., from subarrays of the array of filaments117) and to forward the multiple signals received at multiple input lines in a single line at the analog front end. Themultiplexer22 thus increases an amount of data that can be transmitted within a given time constraint and/or bandwidth constraint. The number of input channels to themultiplexer22 is preferably greater than or equal to the number of output channels of themicrosensor116, and can have any suitable relationship between the number of input lines into themultiplexer22, select lines of the multiplexer, and output lines from themultiplexer22. In some variations, themultiplexer22 can include a post-multiplexer gain in order to reduce capacitance values of the analogfront end23 coupled to themultiplexer22, and which can also be used to limit a number of amplifiers of theelectronics120, such that a single amplifier is coupled to the multiplexer22 (as opposed to amplifiers coupled to each individual sensor); however, themultiplexer22 can alternatively not include any gain producing elements. In some variations, themultiplexer22 can additionally or alternatively include high frequency and/or low frequency limiting elements. However, themultiplexer22 can additionally or alternatively be configured in any other suitable manner. Furthermore, in alternative variations, thesignal conditioning module122 can omit a multiplexer and/or comprise or omit any other suitable element.
• In variations, an interface between the microsensor116 and other elements of theelectronics subsystem120 can be configured in a manner that prevents or otherwise reduces leakage current effects due to a redox potential of the microsensor16 in relation to otherelements electronics subsystem120. In a first configuration, a leakage current effect can result when a diode to ground (e.g., an ESD-diode to ground) is configured at an interface between the microsensor116 and amultiplexer22, as shown inFIG. 5A. To prevent or otherwise reduce the leakage current effect, a set ofdiodes70, comprising a first diode71 (e.g., a first EST-diode) and a second diode72 (e.g., a second ESD-diode), configured at an interface between the microsensor116 and themultiplexer22 can be coupled to an element73 (e.g., inductor, ferrite bead, resistor, etc.) that provides a high resistance to transient voltage spikes and directs any discharge through thesecond diode72 to ground (instead of damaging the electronics subsystem120), as shown inFIG. 5B. Themultiplexer22 can also comprise aswitch75, as shown inFIG. 5C, that allows altering of potentials within the analogfront end23. As shown inFIG. 5C, eliminating a voltage difference (i.e., between Vs and V2) eliminates or otherwise reduces leakage currents that can affect readings from themicrosensor110.
• Thepower management module124 functions to provide dynamic modulation of power transfer to and from elements of themicrosensor patch110, in a manner that enables efficient operation of thesystem100. Preferably, thepower management module124 interfaces with abattery138 and elements of the transmittingunit130 requiring power (e.g., by way of amicroprocessor113, as shown inFIG. 4), as described in further detail below. Additionally, thepower management module124 can further interface with an external processing element of theprocessing subsystem160, such that thepower management module124 can be at least partially implemented in firmware. In one such variation of thepower management module124, wherein power management is achieved in firmware, thepower management module124 can be configured to anticipate power requirements of one or more elements, and to automatically operate at the highest demanded power mode (e.g., voltage) required, while never dropping below a minimum power level required by the elements. Thepower management module124 can also facilitate efficient switching of components to an “off” state when not needed, in order to contribute to lower current consumption. Additionally or alternatively, thepower management module124 can be configured to dynamically trigger high current draw sensing components (e.g., the impedance detection module126) to an “on” state, only when needed, by monitoring other system components (e.g., voltage of a counter electrode13).
• In an example, as shown inFIG. 6A, a group of elements requiring different operating power levels can be coupled to thepower management module124, and thepower management module124 can output power at the highest operating power level anticipated among the elements. Disparate elements can also set a minimum level of power they require, and as elements vary their power requirements, thepower management module124 can then automatically adjust power output such that a power level provided never drops below the lowest power level required. In this variation, elements of themicrosensor patch110 requiring power are thus dynamically provided with their highest demanded power level, to substantially limit energy wasted by thesystem100 and to satisfy power level requirements of all running elements. In another variation of thepower management module124, wherein power management is achieved in firmware, thepower management module124 can be configured to detect elements requiring power, and to automatically operate at the highest demanded power mode (e.g., voltage) required. In an example, a group of elements requiring different operating voltages can be detected, and thepower management module124 can output power at the highest operating voltage detected. As elements vary their voltage requirements, thepower management module124 can then automatically adjust voltage output to meet the highest demanded voltage. In this variation, elements of themicrosensor patch110 requiring power are thus dynamically provided with their highest demanded voltage, to substantially limit energy wasted by thesystem100.
• In other variations, power management can be achieved by thepower management module124 without implementation in firmware, such that power management occurs in circuitry. In these other variations, an example of which is shown inFIG. 6B, power management can comprise providing a set amount of power to elements requiring power, and completely eliminating power transfer to elements not requiring power. Thesystem100 can, however, comprise any other suitable variation of thepower management modules124.
• In relation to thepower management module124, theelectronics subsystem120 can comprise abattery138, which functions to serve as a power source for theelectronics subsystem120. Thebattery138 is preferably coupled to afuel gage38 and a chargingdetection module39, each of which is coupled to the microprocessor113 (described in further detail below). Thebattery138 is preferably a lithium-ion battery that is configured to be rechargeable, but can be any appropriate rechargeable battery (e.g., nickel-cadmium, nickel metal hydride, or lithium-ion polymer). Alternatively, thebattery138 may not be a rechargeable battery. Preferably, thebattery138 is configured to have a profile with a low aspect ratio, contributing to a thin form factor of themicrosensor patch110. However, thebattery138 can be configured to have any appropriate profile such that thebattery130 provides adequate power characteristics (e.g., cycle life, charging time, discharge time, etc.) for thesystem100. In some variations, a thin-film battery can be integrated with the microsensor patch no in order to facilitate substantially continuous analyte detection by thesystem100, independent of themicroprocessor113 and digital electronics of theelectronics subsystem120.
• In embodiments where thebattery138 is rechargeable, theelectronics subsystem120 can also comprise a chargingcoil140 that functions to provide inductive charging for thebattery138, and a chargingdetection module39, in communication with themicroprocessor113, that enable detection of charging of thebattery138. The chargingcoil140 is preferably coupled to thebattery138 and converts energy from an electromagnetic field (e.g., provided by an element of a base station, as described in further detail below), into electrical energy to charge thebattery138. Inductive charging provided by the chargingcoil140 thus facilitates user mobility while interacting with thesystem100. In alternative variations, however, the chargingcoil140 can altogether be omitted (e.g., in embodiments without a rechargeable battery), or replaced by a connection configured to provide wired charging of a rechargeable battery.
• Additionally or alternatively, in some variations, themicrosensor patch110 can comprise a semi-active or fully-active power cell (e.g., implementing microelectromechanical system elements) that functions to absorb and/or release generated energy from any one or more of: body heat of the user, body movement of the user (e.g., with piezoelectric elements, with capacitive elements), static voltage from the environment of the user, light in the environment of the user (e.g., using solar cells), magnetic energy flux, galvanic differentials, and any other suitable energy source to provide secondary backup energy for thesystem100.
• Theimpedance detection module126 is in communication with thesignal conditioning module122 and thepower management module124, and functions to enable detection of a proper interface between the microsensor116 and body fluid (e.g., interstitial fluid) of the user. In facilitating monitoring of impedance, theimpedance detection module126 can thus provide signals that indicate that themicrosensor patch110 is properly coupled to the user (e.g., interfacing with interstitial fluid and experiencing an ˜80% moisture environment) or improperly coupled to the user (e.g., not interfacing properly with interstitial fluid and experiencing a low-moisture environment). Signals from theimpedance detection module126 can further be used to trigger an error correction action (e.g., notification for the user to reapply themicrosensor patch110, automatic manipulation of themicrosensor patch110 to re-establish interface with body fluid, etc.). In one variation, as shown inFIG. 4, the impedance detection module can comprise electronic circuitry configured to communicate with themultiplexer22, theADC24, and thepower management module124, in receiving an impedance signal from themicrosensor116. However, theimpedance detection module126 can additionally or alternatively be configured relative to other elements of theelectronics subsystem120 in any other suitable manner.
• In generating the impedance signal, theimpedance detection module126 can be configured to detect impedance between two electrodes of the array offilaments117 in response to an applied voltage provided in cooperation with thepower management module126 and themicroprocessor113. In one variation, wherein themicrosensor116 comprises a first workingelectrode11, a second workingelectrode12, acounter electrode13, and a reference electrode, theimpedance detection module126 can be configured to detect impedance from two of the first workingelectrode11, the second workingelectrode12, thecounter electrode13, and thereference electrode14, examples of which are shown inFIG. 7. In a specific example, an applied signal can be injected into the system in a working electrode and detected in thereference electrode14. However in other configurations of themicrosensor116, theimpedance detection module126 can be configured to detect impedance from electrodes of themicrosensor116 in any other suitable manner.
• In relation to the applied voltage used for generation and reception of the impedance signal (i.e., for purposes of perturbation), theelectronics subsystem120 is preferably configured to provide an applied voltage waveform having a characteristic value (e.g., average value) near the operating potential of thesignal conditioning module122 of theelectronics subsystem120. In a variation wherein the signal conditioning module122 (e.g., an analogfront end23 of the signal conditioning module122) operates at a shifted potential relative to a potential of an electrode of the microsensor116 (e.g., a reference potential of a reference electrode), the applied voltage waveform preferably has a characteristic value (e.g., average value) near or equal to that of the shifted potential, in order to improve stability of themicrosensor110 when switching back to a current sensing mode (i.e., the primary detection mode). The offset (i.e., shifted potential) is configured to reduce or minimize any disruption to signal integrity when themicrosensor110 is switched from a current sensing mode to an impedance detection mode, and then back to a current sensing mode. In a specific example, as shown inFIG. 8, the applied voltage waveform is shifted about a characteristic value and has a frequency from 50-200 kHz, in relation to a shifted potential of the analogfront end23 relative to thereference electrode14. However, the applied voltage can alternatively have any other suitable characteristics (e.g., characteristic voltage values, frequencies, etc.) defined in relation to the operating potential(s) of any other suitable element of theelectronic subsystem120 related to themicrosensor116.
• In relation to triggering of a measurement using theimpedance detection module126, triggering can occur with any suitable frequency (e.g., in relation to the lifespan of usage of the system100), any suitable regularity (e.g., at regular time intervals, at irregular time intervals, etc.), and/or upon any suitable triggering event. In one variation, theimpedance detection module126 can be configured to provide an impedance signal in association with monitoring of an electrode (e.g., monitoring voltage of the counter electrode13) of themicrosensor116, wherein detection of an out-of-range parameter (e.g., voltage) of the electrode triggers the applied voltage waveform and generation of an impedance signal. As such, theelectronics subsystem120 and the processing subsystem160 (described further below) can be configured to cooperate in continuously detecting a voltage parameter of thecounter electrode13, and theelectronics subsystem120 can be configured to apply the applied voltage waveform and detect the impedance signal when the voltage parameter of the counter electrode satisfies a voltage threshold condition.
• Additionally or alternatively, in another variation, theimpedance detection module126 can be configured to provide an impedance signal upon initial application of thesystem100 to the body of the user. Additionally or alternatively, in another variation, theimpedance detection module126 can be configured to provide impedance signals at regular time intervals (e.g., once every hour) over the course of use of thesystem100 by the user. Additionally or alternatively, in relation to other sensors (e.g., of a mobile computing device associated with the user and thesystem100, of a wearable computing device associated with the user and thesystem100, of thesystem100, etc.) theimpedance detection module126 can be configured to provide an impedance signal in response to a sensor signal that indicates performance of an action by the user. For instance, monitoring of signals provided by an accelerometer and/or gyroscope can be used to indicate that the user is exercising, and that an impedance measurement should be taken (e.g., during exercise, after exercise, etc.) to ensure proper coupling of thesystem100 to the user. In another example, monitoring of body temperature of the user can be used to indicate that the user is showering, and that an impedance measurement should be to ensure proper coupling of thesystem100 to the user. Theimpedance detection module126 can, however, be configured in any other suitable manner.
• Theimpedance detection module126 can further be used to generate notifications pertaining to impedance signal measurements that indicate improper coupling. For instance, a notification can be generated (and transmitted to a mobile computing device of the user) in response to detection of unsuitable impedance derived from comparison between the impedance signal and an impedance threshold condition. However, use of the impedance signal in performing an error correction action can be performed in any other suitable manner.
• The transmittingunit130 functions to receive signals generated by the microsensor patch110 (e.g., by way of the microprocessor113), and to interface with at least one of amobile computing device150, a data processing and/or storage module (e.g., a module external to an on-board storage module, a cloud-based computing module, etc.) by outputting signals based on at least one analyte parameter. The transmittingunit130 thus cooperates with other elements of theelectronics subsystem120 to transmit signals based on sensed analyte parameters, which can be used to facilitate analyses of the user's body chemistry. In variations, the transmittingunit130 includes anantenna132, aradio134 coupling the antenna to themicroprocessor113, and can additionally or alternatively include a linking interface136 (e.g., wireless or wired interface, as described in further detail below).
• Preferably, the transmittingunit130 and themicrosensor patch110 are integrated as a cohesive unit; however, the transmittingunit130 and themicrosensor patch110 can alternatively form a modular unit, wherein one of the transmittingunit130 and themicrosensor patch110 is disposable, and wherein one of the transmittingunit130 and the microsensor patch no is reusable. In variations of the microsensor patch no and the transmittingunit130, elements of the microsensor patch no aside from themicrosensor116 can alternatively be integrated with the transmittingunit130, such that the transmittingunit130 is configured to be reusable and themicrosensor116 of themicrosensor patch110 is configured to be disposable. Modularity in thesystem100 is described in further detail in relation to thehousing190 below.
• Additionally, the transmittingunit130 is preferably configured to output signals based on at least one analyte parameter characterizing body chemistry continuously over the lifetime usage of the transmittingunit130; however, the transmittingunit130 can alternatively be configured to output signals based on at least one analyte parameter at a set of time points (e.g., minutes, hours, days). Still alternatively, the transmittingunit130 can be configured to output signals in a manner that does not interfere with other operations (e.g., signal collection operations) of theelectronics subsystem120. In one such example, the transmittingunit130 can be configured to stop signal transmission whenever theADC24 is collecting signal data from themicrosensor116, in coordination with timing enabled by a clock/watchdog module associated with themicroprocessor113. In variations, the transmittingunit130 can be further configured to output signals upon a user prompt, and/or can comprise a variable sampling rate. For example, the sampling rate can be lower when user is asleep, higher during activity (e.g., exercise), higher when there is a sudden change in a value, higher in response to other stimuli (e.g., if glucose spikes, sampling rate increases for all analytes).
• Theantenna132 of the transmittingunit130 functions to convert electrical signals from themicrosensor patch110 into radio waves, to facilitate communication with one or more devices external to themicrosensor patch110 and/or transmittingunit130 assembly (e.g., by a Bluetooth Low Energy connection). Theantenna132 preferably interfaces with aradio134 coupled to themicroprocessor113, as shown inFIG. 4, but can additionally or alternatively interface with other elements of the transmittingunit130. The antenna is preferably an omnidirectional antenna that radiates radio wave power uniformly primarily in one plane, with the power decreasing with elevation angle relative to the plane; however, the antenna can alternatively be an isotropic antenna that has a spherical radiation patent. Other variations of the antenna can include any appropriate antenna that can be integrated with the form factor of the transmitting unit, while providing appropriate communication with external devices.
• Theradio134 functions to transmit and receive signals from theantenna132, and also facilitates communication with elements of the transmittingunit130 and external devices. Theradio134 and theantenna132 can additionally or alternatively be supplemented with a linkinginterface136, as described in further detail below, but can additionally or alternatively interface with other elements of theelectronics subsystem120.
• The linkinginterface136 functions to transmit an output of at least one element of the microsensor patch no/transmittingunit130 assembly to amobile computing device150. Additionally, the linkinginterface136 can function to transmit and output of at least one element of the microsensor patch no and transmittingunit130 assembly to another element external to the microsensor patch no and transmittingunit130. Preferably, the linkinginterface136 is a wireless interface; however, the linkinginterface136 can alternatively be a wired connection. In a first variation, the linkinginterface136 can include a first module that interfaces with a second module included in amobile computing device150 or other external element (e.g., wrist-borne mobile computing device, head-mounted mobile computing device), wherein data or signals (e.g., microsensor or transceiver outputs) are transmitted from the transmittingunit130 to themobile computing device150 or external element over non-wired communications. The linkinginterface136 of the first variation can alternatively implement other types of wireless communications, such as 3G, 4G, radio, or Wi-Fi communication. In the first variation, data and/or signals are preferably encrypted before being transmitted by the linkinginterface136. For example, cryptographic protocols such as Diffie-Hellman key exchange, Wireless Transport Layer Security (WTLS), or any other suitable type of protocol can be used. The data encryption can also comply with standards such as the Data Encryption Standard (DES), Triple Data Encryption Standard (3-DES), or Advanced Encryption Standard (AES). In variations with data encryption, data can be unencrypted upon transmission to themobile computing device150 associated with the user. However, in an alternative variation, data can remain encrypted throughout transmission to a mobile computing device (associated with the user, not associated with the user) and unencrypted at another module of a processing subsystem160 (e.g., unencrypted in the cloud), wherein information derived from analysis of the data can then be transmitted back to the mobile computing device associated with the user in a secure manner. In this variation, a user can thus pair his/hermicrosensor patch110 with a mobile computing device unassociated with the user for transmission of encrypted data, and then later receive personalized body information at his/her ownmobile computing device150 after processing in the cloud.
• In a second variation, the linkinginterface136 is a wired connection, wherein the linkinginterface136 includes a wired jack connector (e.g., a ⅛″ headphone jack, a USB connection, a mini-USB connection, a lightning cable connection, etc.) such that the transmittingunit130 can communicate with themobile computing device150 and/or an external element through a complementary jack of the mobile device and/or external element. In one specific example of the linkinginterface136 that includes a wired jack, the linking interface is configured only to transmit output signals from the transmittingunit130/microsensor patch110. In another specific example, the linkinginterface136 is configured to transmit data to and from at least one element of transmittingunit130/transdermal path110 assembly and amobile computing device150. In this example, the linkinginterface136 can transmit output signals into themobile computing device150 through an input of the jack of themobile computing device150 and can retrieve data from an output of the jack of themobile computing device150. In this example, the linkinginterface136 can communicate with themobile computing device150 via inter-integrated circuit communication (I2C), one-wire, master-slave, or any other suitable communication protocol. However, the linking interface can transmit data in any other way and can include any other type of wired connection that supports data transfer between the transmittingunit130 and/ormicrosensor patch110, and themobile computing device150.
• As noted above, theelectronics subsystem120 can include any other suitable module(s) and/or be configured in any other suitable manner. For instance, theelectronics subsystem120 can include or be in communication with an actuator configured to automatically perform an action (e.g., vibration, provision of a biasing force) that biases the microsensor into communication with interstitial fluid of the user, in response to detection of unsuitable impedance derived from comparison between an impedance signal and an impedance threshold condition.
1.1.3 System—Housing
• Thehousing190 supports themicrosensor116 and theelectronics subsystem120, and functions to facilitate robust coupling of themicrosensor patch110 to the user in a manner that allows the user to wear the microsensor patch no for a sufficient period of time (e.g., one week, one month, etc.). Thehousing190 can also function to protect elements of the microsensor patch no from physical damage over the lifetime usage of themicrosensor patch110. Preferably, at least one portion of thehousing190 is flexible to facilitate adhesion to the user and compliance with skin of the user as the user moves in his/her daily life; however, at least a portion of thehousing190 can alternatively be rigid in order to provide more robust protection against physical damage. In an embodiment where a portion of thehousing190 is flexible, other elements of the microsensor patch no can also be flexible (e.g., using a thin film battery, using flexible electronics, etc.) to facilitate adhesion to the user and compliance as the user moves about in his/her daily life. In one variation, thehousing190 can comprise a single unit that entirely houses themicrosensor116 and theelectronics subsystem120. In this variation, thehousing190 can be configured to couple to the user using any suitable coupling mechanism (e.g., adhesive coupling mechanism, strap-based coupling mechanism, etc.). However, in other variations, thehousing190 can alternatively be modular and comprise a set of portions, each portion configured to enable coupling of themicrosensor116 to the user and/or to house elements of theelectronics subsystem120. Modularity of thehousing190 can thus allow portions of thesystem100 to be disposable and/or reusable.
• In one such modular variation of thehousing190, as shown inFIG. 9, the housing can comprise afirst housing portion191 and asecond housing portion196, wherein thefirst housing portion191 is configured to facilitate coupling of filaments of themicrosensor116 to the user, and thesecond housing portion196 is configured to house elements of theelectronics subsystem120 and to couple theelectronics subsystem120 to themicrosensor116 by way of thefirst housing portion191. As such, thefirst housing portion191 and thesecond housing portion196 of this variation are preferably configured to mate with each other in a complementary manner (e.g., with a male-female coupling mechanism, with a magnetic coupling mechanism, with a latch-based coupling mechanism, with a lock-and-key based coupling mechanism, etc.). In a specific example, as shown inFIGS. 10A-10B, thefirst housing portion191′ includes anopening192′, and asecond housing portion196′ is insertable into the opening of the first housing portion in a first configuration, wherein coupling between thefirst housing portion191′ and thesecond housing portion196′ provides a hermetic seal between thefirst housing portion191 and thesecond housing portion196. In more detail, as shown inFIG. 10C, thefirst housing portion191 can include an o-ring193 (e.g., an o-ring molded onto the material of the first housing portion) at a perimeter of theopening192, and a perimeter region of thesecond housing portion196 can include a recessed region197 that interfaces with the o-ring193 in a manner that provides a hermetic seal. In this specific example, theopening192 and thesecond housing portion196 each have substantially circular footprints; however, theopening192 and thesecond housing portion196 can additionally or alternatively have any other suitable footprints or be configured in any other suitable manner.
• In the specific example, as shown inFIGS. 10A-10B, thefirst housing portion191′ can comprise anadhesive substrate91 having amicrosensor opening92, amicrosensor interface substrate93 superior to the adhesive substrate and configured to pass themicrosensor92 through themicrosensor opening92, acoupling ring94 configured to retain the position of themicrosensor interface substrate93 relative to theadhesive substrate91 and to provide an interface for mating with thesecond housing portion196, and aflexible cover95 ensheathing thecoupling ring94, coupled to theadhesive substrate91, and configured to maintain coupling between theadhesive substrate191, themicrosensor interface substrate93, and thecoupling ring94. In relation to the configuration described above, theadhesive substrate91 is configured to facilitate adhesion of themicrosensor patch110 to the user at an inferior surface of the adhesive substrate, and theflexible cover95 is configured to provide theopening192′ that receives thesecond housing portion192.
• Thesecond housing portion196 of the specific example is rigid, and configured to form a shell about theelectronics subsystem120, while including openings that provide access for a set ofcontacts98 that interface theelectronics subsystem120 with themicrosensor interface substrate93 when thefirst housing portion191 is coupled to thesecond housing portion196. In relation to themicrosensor interface substrate93 of thefirst housing portion191, and in relation to a circular (or otherwise axially symmetric) configuration of an interface between thesecond housing portion196 and theopening192 of thefirst housing portion191, themicrosensor interface substrate93 of the specific example can include a circular printed circuit board comprising a set ofconcentric ring contacts97, as shown inFIG. 10A, that interface electronics of thesecond housing portion196 with filaments of themicrosensor116. As such, the set of contacts98 (e.g., digital contacts) of electronics of thesecond housing portion196 can properly interface with themicrosensor116 in any rotational position of thesecond housing portion196 within thefirst housing portion191, as shown inFIG. 10B. In alternative variations of this specific example however, orientation-unspecific coupling between thefirst housing portion191 and thesecond housing portion196 can be achieved in any other suitable manner. In still alternative variations of this specific example, thefirst housing portion191 and thesecond housing portion196 can be configured to couple with a set orientation in order to ensure proper communication between the microsensor116 and theelectronics subsystem120.
• In variations of thehousing190 comprising afirst housing portion191 and asecond housing portion196, thefirst housing portion191 and thesecond housing portion196 can be coupled together and/or coupled to the user by way of apatch applicator180, as described in further detail below. Furthermore, other variations of modularity can comprise any other suitable distribution of themicrosensor116 and elements of theelectronics subsystem120 across portions of the housing in any other suitable manner. For instance, in one such variation, themicrosensor116, themultiplexer22, and the analogfront end93 of theelectronics subsystem120 can be coupled to a separate battery (e.g., a thin film battery) within a disposable portion of thehousing190, and other elements of theelectronics subsystem120 can be supported by a reusable portion of thehousing190. Thesystem100 can, however, comprise any other suitable distribution of elements across thehousing190 in a modular fashion.
1.2 System—Processing Subsystem
• Theprocessing subsystem160 is in communication with theelectronics subsystem120 and functions to generate analyses pertaining to the user's body chemistry, and to transmit information derived from the analyses to the user at an electronic device associated with the user. As shown inFIG. 1, theprocessing subsystem160 can be implemented in one or more of: a computer machine, a remote server, a cloud computing system, a microprocessor, processing hardware of a mobile computing device (e.g., smartphone, tablet, head-mounted mobile computing device, wrist-borne mobile computing device, etc.) and any other suitable processing system. In one variation, theprocessing subsystem160 comprises afirst module161 configured to generate an analysis indicative of an analyte parameter of the user and derived from a signal stream from themicrosensor116 and an impedance signal from theelectronics subsystem120. Additionally, in this variation, theprocessing subsystem160 comprises asecond module162 configured to render information derived from the analysis at an electronic device (e.g., mobile computing device iso) associated with the user, thereby facilitating monitoring of body chemistry of the user. In this variation, the modules of theprocessing subsystem160 can be implemented in a hardware module and/or a software module. In variations, asoftware module163 can be implemented, at least in part, as a native software application executing on amobile computing device150 associated with the user, wherein the user has a user account associated with the native software application.
• In more detail, thesoftware module163 functions to analyze an output provided by the transmittingunit130 of theelectronics subsystem120, and to communicate an analysis of the output back to the user, so that the user can monitor his/her body chemistry. Preferably, thesoftware module163 analyzes at least one analyte parameter in order to determine a metric providing information about a user's body chemistry. In one variation, the software module can determine that a body analyte parameter (e.g., glucose level) of the user is too low or less than ideal, and facilitate a behavior change in the user by providing a body chemistry metric indicating a hypoglycemic state. In this variation, the software module can additionally determine that the body analyte parameter (e.g., glucose level) of the user is within a proper range based on a determined metric. The software module of this variation can additionally determine that the body analyte parameter (e.g., glucose level) of the user is too high and facilitate a behavior change in the user by providing a body chemistry metric indicating a hyperglycemic state.
• In another example, the software module can analyze an output provided by the transmittingunit130 based on a set of parameters for multiple analytes characterizing a user's body chemistry, at a set of time points, and determine at least one metric based on the set of parameters at the set of time points. The software module can then determine and output at least one of a temporal trend in a metric, a temporal trend in an analyte parameter, absolute values of a metric, changes in value of a metric, absolute values of an analyte parameter, and changes in value of an analyte parameter. Thesoftware module163 in this example can further be configured to communicate a suggestion to the user based on an analysis determined from the set of parameters for multiple analytes.
• The software module preferably incorporates at least one of user health condition, user characteristics (e.g., age, gender, ethnicity), and user activity in analyzing an output provided by the transmittingunit130. In one specific example, if a user sets a desired body glucose level range, which is entered into the software module, the software module can be configured to facilitate provision of alerts notifying the user of short-term risks (e.g., diabetic crash), long-term risks (e.g., worsening diabetic condition), and risk of exiting the desired body glucose level range. In another specific example, the software module can compare analyte parameters and/or a metric characterizing the user's body chemistry to other users with similar health conditions or characteristics (e.g., age, gender, ethnicity). In yet another example, the software module can be able to correlate at least one analyte parameter or metric to a user activity, such that the user is provided with information relating a value of the analyte parameter and/or metric to an activity that he or she has performed. The software module can additionally or alternatively provide an analysis that includes any other health- and/or user-related information that can be useful in treating, maintaining, and/or improving a health condition of a user.
• As shown inFIGS. 1,11A, and11B, the software module can be implemented, at least in part, as an application executable on amobile computing device150. As described above, themobile computing device150 is preferably a smartphone but can also be a tablet, laptop computer, PDA, e-book reader, head-mounted computing device, smart-watch, or any other mobile device. The software module can alternatively be an application executable on a desktop computer or web browser. The software module preferably includes an interface that accepts inputs from the user (e.g., user health condition, user characteristics, user activity), and uses these inputs in analyzing an output provided by the transmittingunit130. Preferably, the software module also includes an interface that renders an analysis based on sensed analytes and/or user inputs in some form. In an example, the software module includes an interface that summarizes analyte parameter values in some manner (e.g., raw values, ranges, categories, changes), provides a trend (e.g., graph) in at least one analyte parameter or body chemistry metric, provides alerts or notifications, provides additional health metrics, and provides recommendations to modify or improve body chemistry and health metrics. In another example, the software module can implement two interfaces: a first interface accessible by a user, and a second interface accessible by a health care professional servicing the user. The second interface can provide summarized and detailed information for each user that the health care professional interacts with, and can further include a message client to facilitate interactions between multiple users and the health care professional. The software module can additionally or alternatively access a remote network or database containing health information of the user. The remote network can be a server associated with a hospital or a network of hospitals, a server associated with a health insurance agency or network of health insurance agencies, a server associated with a third party that manages health records, or any other user- or heath-related server or entity. The software module can additionally or alternatively be configured to accept inputs from another entity, such as a healthcare professional, related to the user.
• Thesoftware module163 can additionally or alternatively execute fully or in part on a remote server. In a first variation, the software module can be a cloud-computing-based application that performs data analysis, calculations, and other actions remotely from themobile computing device150. In one example of the first variation, themobile computing device150 can receive an output of the transmittingunit130 via the linkinginterface136 and then transfer the output to the remote server upon which the software module executes. In the first variation, signals are preferably transferred via a wireless connection, such as a Bluetooth connection, 3G or 4G cellular connection, and/or via a Wi-Fi internet connection. In another example of the first variation, amobile computing device150 can function to transmit data to and/or receive data from the software module. In a second variation, the software module can include a first software component executable on amobile computing device150, such as an application that manages collection, transmission, retrieval, and/or display of data. In the second variation, the software module can further include a second software component that executes on the remote server to retrieve data, analyze data, and/or manage transmission of an analysis back to themobile computing device150, wherein the first software component manages retrieval of data sent from the second software component and/or renders of a form of the analysis on a display of themobile computing device150. However, the software module can include any number of software components executable on anymobile computing device150, computing device, and/or server and can be configured to perform any other function or combination of functions.
• As shown inFIG. 12A, thesoftware module163 can further be integrated with anotification module165 configured to provide an alert or notification to a user and/or health care professional based on the analysis of the output. Thenotification module165 functions to access an analysis provided by the software module and to control transmission of anotification166 to at least one of a user and a healthcare profession interacting with the user. In one variation, thenotification module165 receives an analysis of the software module being executed on amobile computing device150, and generates anotification166 based upon the analysis. In this variation, a form of the analysis is preferably transmitted from the software module, executing on themobile computing device150, to thenotification module165, wherein themobile computing device150 accesses the analysis either from the software module executing on themobile computing device150 or from the software module executing on a remote server and in communication with themobile computing device150. Thenotification module165 preferably controls transmission of thenotification166 to the user, such as by triggering a display of themobile computing device150 to display a form of the notification, or by generating and/or transmitting an email, SMS, voicemail, social media platform (e.g., Facebook or Twitter) message, or any other message accessible by the user and which contains thenotification166. Thenotification module165 can also convey thenotification166 by triggering a vibration of themobile device160, and/or by altering the state (i.e., ON or OFF) of one or more light sources (e.g., LEDs) of themobile computing device150. However, thenotification module165 can alternatively manage the transmission of any other information and function in any appropriate manner.
• Thenotification166 preferably contains information relevant to a body chemistry status of the user. Thenotification166 can additionally include an explicit directive for the user to perform a certain action (e.g., eat, rest, or exercise) that affects the body chemistry of the user. Therefore, thenotification166 preferably systematically and repeatedly analyzes a body chemistry status of the user based on at least one analyte parameter of the user and provides and alert and/or advice to manage and monitor a user's body chemistry substantially in real time. In one example, thenotification166 can further include information related to what or how much to eat, where and how long to run, level of exertion, and/or how to rest and for how long in order to appropriately adjust body chemistry. In other examples, thenotification166 can include any appropriate information relevant to monitoring a body chemistry metric of the user.
• In still other examples, as shown inFIG. 12B, thenotification166 can indicate one or more of: a current level of a measured analyte (e.g., represented in hue, represented in saturation, represented in intensity, etc. of a graphical rendering); a trending direction for the level of the measured analyte (e.g., represented in a feature gradient within a graphical rendering); a lower bounding level and an upper bounding level between which the level of the measured analyte is traversing; a trending direction of a level of a measured analyte (e.g., represented in an arrow of a graphical rendering); a quantification of a level of a measured analyte (e.g., represented as rendered text); a summary of a level of a measured analyte (e.g., represented as rendered text); a percent of time within a time duration (e.g., one day) that the level of the measured analyte is within a target range (e.g., healthy range); and historical behavior of a level of a measured analyte (e.g., represented as historical “ghosting” of a rendering based upon a previous analyte level).
• Additionally or alternatively, in still other examples, as shown inFIG. 12C, thenotification166 can include a graphical rendering that shows analyte data from past to present using a line graph representation, wherein an amount (e.g., concentration) of the analyte is represented along a first axis and time is represented along a second axis. In these examples, the graphical rendering can further include a “predicted region” based upon the analysis of theprocessing subsystem160, wherein the predictedregion66 depicts a prediction of where the analyte level will be at a future time point, and a width of the predictedregion66 indicates confidence in the prediction.
• In relation to theprocessing subsystem160 and analyses generated at theprocessing subsystem160, theprocessing subsystem160 can be coupled to or comprise adata storage unit170, as shown inFIG. 13. Thedata storage unit170 functions to retains data, such as an analysis provided by a software module, anotification166, and/or any other output of any element of thesystem100. Thedata storage unit170 can be implemented with themicrosensor patch110, transmittingunit130,mobile computing device150, personal computer, web browser, external server (e.g., cloud), and/or local server, or any combination of the above, in a network configured to transmit, store, and receive data. Preferably, data from thedata storage unit170 is automatically transmitted to any appropriate external device continuously; however, data from thedata storage unit170 can alternatively be transmitted only semi-continuously (e.g., every minute, hourly, daily, or weekly). In one example, data generated by any element can be stored on a portion of thedata storage unit170 when the linkinginterface136 is not coupled to an element external to the microsensor patch no/transmittingunit130 assembly. However, in the example, when a link is established between the linkinginterface136 and an external element, data can then be automatically transmitted from thestorage unit170. In other examples, thedata storage unit170 can alternatively be prompted to transmit stored data by a user or other entity. Operation modes related to device pairing and information transfer are further described in relation to the base station of Section 1.4 below.
1.3 System—Applicator
• As shown inFIG. 1, thesystem100 can further comprise apatch applicator180, which functions to facilitate application of at least one of the microsensor patch no and the transmittingunit130. Thepatch applicator180 preferably accelerates the a portion of the housing with themicrosensor116 toward skin of the user, thereby causing themicrosensor116 to penetrate skin of the user and sensing regions of the microsensor to access interstitial fluid of the user. However, thepatch applicator180 can additionally or alternatively facilitate coupling of themicrosensor116 to the user using one or more of: skin stretching, skin permeabilization, skin abrasion, vibration, and/or any other suitable mechanism, variations of which are shown inFIGS. 14A-14C. In a first variation, as shown inFIG. 15A, thepatch applicator180′ can be incorporated into afirst housing portion191 of ahousing190 of thesystem100 and can comprise an elastic pin181 (e.g., spring-loaded pin) configured to complement a recess of asecond housing portion196. In this variation, a normal force applied to a broad surface of thesecond housing portion196 initially causes theelastic pin181 to retract, and rebounding of theelastic pin181 into the recess of thesecond housing portion196 biases and accelerates themicrosensor116 into the skin of the user.
• In a second variation, as shown inFIG. 15B, thepatch applicator180″ implements elastic portions of thehousing190, which can be used to retract a housing portion with themicrosensor116 and to release the housing portion, thereby accelerating themicrosensor116 into skin of the user.
• In a third variation, the patch applicator cooperates with afirst housing portion191 and asecond housing portion196, wherein the patch applicator comprises a first applicator portion configured to surround thehousing190 and interface with thesecond housing portion196, and a second applicator portion configured to accelerate the second housing portion toward skin of the user. In a first specific example of the third variation, as shown inFIG. 16A, thepatch applicator180acomprises a ram-and-catch mechanism, wherein twisting of arotatable component83 of thepatch applicator180atransitions aplunger84 of thepatch applicator180afrom a restingconfiguration84ato a loadedconfiguration84b, as shown inFIGS. 16B and 16C, and pushing of therotatable component83 of thepatch applicator180areleases theplunger84 back to the restingconfiguration84a(as shown inFIG. 16D), thereby accelerating themicrosensor116 toward skin of the user during application of the microsensor patch no to the user. In more detail, in the first specific example, twisting of therotatable component83 transitions theplunger84 along rampedsurfaces85 of thepatch applicator180ato the loadedconfiguration84a, where theplunger84 rests ontriggers86 of thepatch applicator180a. Then, as shown inFIG. 16D, pressing of therotatable component83 provides an outward biasing force on the triggers86 (e.g., due to wedge-shaped morphology of the triggers that interacts with a complementary portion of the rotatable component83), thereby releasing theplunger84 to the restingconfiguration84a. In this specific example, a set ofribs87 coupled to a wall of thepatch applicator180 surrounding theplunger84 maintain plunger alignment.
• In a second specific example of the third variation, as shown inFIG. 17, the patch applicator180bcomprises anelastic component89 housed within and coupled to a translatingcomponent88 of the patch applicator180b, wherein the translatingcomponent88 comprises aplunger84′ and is configured to translate along a first axis. The patch applicator180bfurther comprises atrigger188 coupled to abiasing spring189 and configured to translate along a second axis perpendicular to the first axis, between a holding position188aand a releasing position188b. In the second specific example, the translatingcomponent88 is biased in holding position188a, and pushing of the translatingcomponent88 places a lateral biasing force on thetrigger188 against the biasing spring189 (e.g., due to wedge-shaped morphology of thetrigger188 that interacts with a complementary portion of the translating component88), thereby releasing theplunger84′ to accelerate themicrosensor116 toward skin of the user. In pushing the translatingcomponent88, compression of theelastic component89 creates a reverse biasing force that automatically releases the translatingcomponent88 toward the resting configuration88a.
• Thepatch applicator180 can alternatively be configured to receive themicrosensor patch110, to stretch the skin of the user isotropically in two dimensions to facilitate application, and to push the microsensor patch no/transmittingunit130 assembly onto the user's stretch skin. Still alternatively, thepatch applicator180 can include any other suitable applicator, variations and examples of which are described in U.S. App. No. 62/025,174 entitled “System for Monitoring Body Chemistry” and filed on 16 Jul. 2014. Still other variations of thesystem100 can entirely omit apatch applicator180.
1.4 System—Base Station
• As shown inFIG. 1, the system can include abase station5 that functions to receive the microsensor patch110 (e.g., within a second housing portion196). In receiving themicrosensor patch110, thebase station5 can include alignment elements6 (e.g., protrusions, recesses, magnetic alignment elements, etc.) that facilitate alignment of the microsensor patch no within the base station, as shown inFIG. 18A. Thebase station5 can additionally or alternatively facilitate charging of a rechargeable battery of themicrosensor patch110 by including elements that generate an electromagnetic field that interacts with a charging coil coupled to the battery, thereby charging thebattery138. Thebase station5 can additionally or alternatively be used to transition the microsensor patch between different operational states, in relation to data transfer between themicrosensor patch110, amobile computing device150 associated with the user, and modules of a processing subsystem160 (e.g., cloud module) as shown inFIG. 19. In afirst operation mode5a, the transmittingunit130 of themicrosensor patch110 and themobile computing device150 can pair/bond only when thesecond housing portion196 of themicrosensor patch110 is in communication with the base station5 (e.g., aligned within the base station5). Thus, in thefirst operation mode5a, themicrosensor patch110 can transmit and receive data (e.g., compact raw data compounded into a plurality of bits over Bluetooth communication). In asecond operation mode5bwherein themicrosensor patch110 is not in communication with thebase station5, themicrosensor patch110 can be configured to only transmit data (but not receive data), thereby reducing energy usage, preventing man-in-the-middle attack, and preventing tampering. As such, thesecond operation mode5bprevents reading of data from themicrosensor patch110 by a fraudulent entity, without gaining physical access to themicrosensor patch110.
• The operation modes of thesystem100 enabled by the microsensor patch, thebase station5, themobile computing device150, and theprocessing subsystem160 are further detailed inFIG. 19. In relation to pairing with themicrosensor patch110 in thefirst operation mode5a, themobile computing device150 functions to provide one or more of: data relay, data visualization, data storage, notification, and action functions (e.g., as described in relation to thesoftware module163 described above). In communicating information between themobile computing device150 and a cloud module of theprocessing subsystem160, themobile computing device150 can be configured to transmit raw data in Javascript Object Notation (JSON) format (or any other suitable format) to be processed in the cloud, and analyte data, notifications, and alerts (e.g., as derived from an analysis) can be transmitted back to themobile computing device150 in JSON format (or any other suitable format). The cloud module of theprocessing subsystem160 can thus serve to enable authentication of the user (e.g., in association with a user account of a native application) and/or data, data storage, data processing, notification, and prediction functions, as described in relation to theprocessing subsystem160 described above. Thus, thesystem100 is configured for fault tolerance, wherein themicrosensor patch110 stores data when faulty operation of themobile computing device150 occurs, and failure of theprocessing subsystem100 results in data storage at the mobile computing device. Thesystem100 can, however, be configured in any other suitable manner.
• As shown inFIG. 18B, thebase station5 and thepatch applicator180 can be configured to couple together, thus facilitating portability of thebase station5 andpatch applicator180. However, thebase station5,patch applicator180, and microsensor no can alternatively be configured to couple or not couple together in any other suitable manner.
1.5 System—Calibration
• The microsensor patch no is preferably calibrated to prevent signal degradation and to mitigate the effects of transient effects experienced during analyte sensing. The primary sensing mechanism is potentiometric for small analytes (e.g., potassium, sodium, calcium), and amperometric for large molecules (e.g., glucose, lactic, creatinine). In a first variation, themicrosensor patch110 passively detects analytes by detecting an impedance and/or capacitance change, as well as a voltage change when an analyte or analyte concentration contacts themicrosensor116. Calibration can occur by normalizing sensing measurements relative to a grounded portion of themicrosensor116, such as a reference electrode.
• In a second variation, themicrosensor patch110 can implement active impedance calibration, wherein a drive voltage is implemented by the electronics subsystem in of the microsensor patch no, and voltage and impedance and/or capacitance changes are detected. The drive voltage is preferably applied in a sinusoidal pattern, but can alternatively be applied in any appropriate pattern. In the second variation, sensed analytes or analyte concentrations are characterized by changes in impedance, and noise is characteristically distinguished from analyte detection by monitoring changes in voltage unaccompanied by changes in impedance or capacitance. The second variation thus employs a conductometric measurement to calibrate the microsensor patch no. Impedance measurements can also be used to address shift in a reference electrode (e.g., in the first variation described above).
• In a third variation, the microsensor patch no can employ injection of a volume of a calibration solution with a known concentration of at least one analyte, in order to calibrate the microsensor patch no. In an example of the third variation, the calibration solution can have a known concentration of at least one analyte, such that changes (e.g., changes in electrical parameters) detected by the microsensor patch no in response to the calibration solution can be used to normalize measurements resulting from sensed analytes or analyte concentrations occurring after injection of the volume of calibration solution. In the third variation, the calibration solution can be injected automatically and periodically over the lifetime usage of the transdermal patch; however, the calibration solution can alternatively be injected when prompted by a user or other entity.
• In a fourth variation, themicrosensor patch110 can include a membrane comprising a known concentration and/or release profile of at least one analyte, in order to calibrate the microsensor patch no. In an example of the fourth variation, the membrane can have a known concentration and release profile of at least one analyte, such that changes (e.g., changes in electrical parameters) detected by the microsensor patch no in response to the membrane can be used to normalize measurements resulting from sensed analytes or analyte concentrations. In the fourth variation, the membrane can be a degradable membrane, such that degradation of the membrane over time releases analytes from the membrane. Alternatively, the membrane can be manufactured with specific porosity, contributing to a certain analyte release profile.
• In a fifth variation, the microsensor patch no can include a coating or a cap comprising a soluble species (e.g., analyte/ion) with a well-known solubility, in order to calibrate the microsensor patch no. In an example of the fifth variation, the soluble species maintains a known concentration of the species within the vicinity of a filament that can be used to normalize and/or calibrate a signal. Examples of soluble species include low solubility, biocompatible calcium salts, such as calcium carbonate, calcium phosphate, and dicalcium phosphate for calcium sensing. Other suitable soluble species can be used to calibrate other analytes.
• In alternative variations, themicrosensor patch110 can use any other suitable calibration method. For instance, the transdermal patch can be pre-staged, prepped, loaded, or activated to have a set calibration state enabling calibration of the system after application to the user within a desired period of time (e.g., an 85 mg/dl calibration state equilibrated after insertion within a period of 2 hours).
• As a person skilled in the art will recognize from the previous detailed description and from the figures and claims, modifications and changes can be made to the described embodiments, variations, and examples of thesystem100 without departing from the scope of thesystem100.
2. Method
• As shown inFIG. 20, a method200 for monitoring body chemistry of a user comprises: receiving a second housing portion into an opening of a first housing portion S210, the first housing portion supporting a microsensor including a first working electrode, a second working electrode, a reference electrode, and a counter electrode, and the second housing portion supporting an electronics subsystem configured to receive a signal stream from the microsensor; after interfacing with the second housing portion, accelerating the second housing portion toward skin of the user S220, thereby delivering sensing regions of the microsensor into interstitial fluid of the user; generating an impedance signal, from two of the first working electrode, the second working electrode, the reference electrode, and the counter electrode, in response to applying a voltage, near a shifted potential different than a reference potential of the reference electrode S230, wherein the shifted potential is associated with a signal conditioning module of the electronics subsystem; at a processing system in communication with the electronics subsystem, receiving the signal stream and the impedance signal S240; at the processing system, generating an analysis indicative of an analyte parameter of the user and derived from the signal stream and the impedance signal S250; and transmitting information derived from the analysis to an electronic device associated with the user, thereby facilitating monitoring of body chemistry of the user S260.
• Themethod200 functions to provide continuous monitoring of a user's body chemistry through reception and processing of signals associated with of one or more analytes present in the body of the user, and to provide an analysis of the user's body chemistry to the user and/or an entity (e.g., health care professional, caretaker, relative, friend, acquaintance, etc.) associated with the user. Alternatively, themethod200 can function to detect a user's body chemistry upon the user's request or sporadically, and/or can provide an analysis of the user's body chemistry only to the user. The method is preferably implemented, at least in part, using an embodiment, variation, or example of elements of thesystem100 described inSection 1 above; however, themethod200 can additionally or alternatively be implemented using any other suitable system.
• Variations of thesystem100 andmethod200 include any combination or permutation of the described components and processes. Furthermore, various processes of the preferred method can be embodied and/or implemented at least in part as a machine configured to receive a computer-readable medium storing computer-readable instructions and/or in the cloud. The instructions are preferably executed by computer-executable components preferably integrated with a system and one or more portions of a control module and/or a processor. The computer-readable medium can be stored on any suitable computer readable media such as RAMs, ROMs, flash memory, EEPROMs, optical devices (CD or DVD), hard drives, floppy drives, or any suitable device. The computer-executable component is preferably a general or application specific processor, but any suitable dedicated hardware device or hardware/firmware combination device can additionally or alternatively execute the instructions.
• The FIGURES illustrate the architecture, functionality and operation of possible implementations of systems, methods and computer program products according to preferred embodiments, example configurations, and variations thereof. In this regard, each block in the flowchart or block diagrams may represent a module, segment, step, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block can occur out of the order noted in the FIGURES. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
• As a person skilled in the art will recognize from the previous detailed description and from the figures and claims, modifications and changes can be made to the preferred embodiments of the invention without departing from the scope of this invention defined in the following claims.

Claims (21)

We claim:

1. A system for monitoring body chemistry of a user, the system comprising:

a housing comprising a first housing portion coupleable to the user and including an opening, and a second housing portion insertable into the opening of the first housing portion in a first configuration, the first housing portion supporting:

a microsensor comprising a first working electrode, a second working electrode, a reference electrode, and a counter electrode, and configured to access interstitial fluid of the user upon coupling of the housing to the user in the first configuration of the housing, and

the second housing portion supporting: an electronics subsystem comprising a signal conditioning module configured to receive a signal stream, from the microsensor, and configured with a shifted potential different than a reference potential of the reference electrode, wherein the electronics subsystem is configured to detect an impedance signal derived from two of the first working electrode, the second working electrode, the reference electrode, and the counter electrode in response to an applied voltage near the shifted potential; and

a processing subsystem in communication with the electronics subsystem and comprising: a first module configured to generate an analysis indicative of an analyte parameter of the user and derived from the signal stream and the impedance signal, and a second module configured to render information derived from the analysis at an electronic device associated with the user, thereby facilitating monitoring of body chemistry of the user.

2. The system ofclaim 1, wherein the electronics subsystem and the processing subsystem are configured to cooperate in continuously detecting a voltage parameter of the counter electrode, and wherein the electronics subsystem is configured to apply the applied voltage and detect the impedance signal when the voltage parameter of the counter electrode satisfies a voltage threshold condition.

3. The system ofclaim 2, wherein the processing subsystem is configured to generate a notification at the electronic device of the user, in response to detection of unsuitable impedance derived from comparison between the impedance signal and an impedance threshold condition.

4. The system ofclaim 2, wherein an actuator of the electronics subsystem is configured to automatically perform an action that biases the microsensor into communication with interstitial fluid of the user, in response to detection of unsuitable impedance derived from comparison between the impedance signal and an impedance threshold condition.

5. The system ofclaim 1, wherein the first module of the processing subsystem is configured to generate a predicted value of the analyte parameter at a future time point in the analysis, and the second module of the processing subsystem is configured to render a line graph including a predicted region, wherein the predicted region depicts the predicted value at the future time point, and a width of the predicted region indicates confidence in the predicted value.

6. The system ofclaim 1, further comprising an applicator configured to accelerate the second housing portion toward skin of the user, thereby causing the microsensor to penetrate skin of the user and sensing regions of the microsensor to access interstitial fluid of the user.

7. The system ofclaim 1, wherein the first housing portion includes a microsensor interface substrate comprising a set of concentric ring contacts configured to interface electronics of the second housing portion with filaments of the microsensor, in any rotated configuration associated with insertion of the second housing portion into the opening of the first housing portion.

8. A method for monitoring body chemistry of a user, the method comprising:

receiving a second housing portion into an opening of a first housing portion, the first housing portion supporting a microsensor including a first working electrode, a second working electrode, a reference electrode, and a counter electrode, and the second housing portion supporting an electronics subsystem configured to receive a signal stream from the microsensor;

accelerating the second housing portion toward skin of the user, thereby delivering sensing regions of the microsensor into interstitial fluid of the user;

generating an impedance signal, from two of the first working electrode, the second working electrode, the reference electrode, and the counter electrode, in response to applying an applied voltage, near a shifted potential different than a reference potential of the reference electrode, wherein the shifted potential is associated with a signal conditioning module of the electronics subsystem;

at a processing system in communication with the electronics subsystem, receiving the signal stream and the impedance signal;

at the processing system, generating an analysis indicative of an analyte parameter of the user and derived from the signal stream and the impedance signal; and

transmitting information derived from the analysis to an electronic device associated with the user, thereby facilitating monitoring of body chemistry of the user

9. The method ofclaim 8, further comprising: by way of the electronics subsystem and the processing subsystem, substantially continuously detecting a voltage parameter of the counter electrode, and applying the applied voltage to generate the impedance signal whenever the voltage parameter of the counter electrode satisfies a voltage threshold condition.

10. The method ofclaim 8, further comprising transitioning the electronics subsystem into a first operation mode upon providing communication between the electronics subsystem and a base station, configured to charge a battery of the electronics subsystem, wherein the first operation mode permits data transfer and reception between the electronics subsystem and a mobile computing device associated with the user.

11. The method ofclaim 9, further comprising detecting an uncoupling state between the microsensor and the user based upon a comparison between the impedance signal and a threshold condition, and generating an alert in response to the uncoupling state.

12. The method ofclaim 11, further comprising activating an actuator of the electronics subsystem, wherein activating the actuator biases the microsensor into interstitial fluid of the user upon detection of the uncoupling state.

13. The method ofclaim 8, further comprising: at the processing subsystem, generating a predicted value of the analyte parameter at a future time point in the analysis, and rendering a line graph including a predicted region at a display of a mobile computing device associated with the user, wherein the predicted region depicts the predicted value at the future time point, and a width of the predicted region indicates confidence in the predicted value.

14. The method ofclaim 13, further comprising rendering a present state of the analyte parameter, indicating a future state toward which the analyte parameter is predicted to trend, and a percent of time within a time duration at which values of the analyte parameter are within a target range.

15. The method ofclaim 8, wherein accelerating the second housing portion toward skin of the user comprises transitioning a plunger of an applicator from a resting state to a loaded configuration, and releasing the plunger to accelerate the second housing portion toward skin of the user, in response to release of a trigger of the applicator by the user.

16. A system for monitoring body chemistry of a user, the system comprising:

a housing supporting:

a microsensor comprising a first working electrode, a second working electrode, a reference electrode, and a counter electrode, and configured to access interstitial fluid of the user upon coupling of the housing to the user, and

an electronics subsystem comprising a signal conditioning module configured to receive a signal stream, from the microsensor, and configured with a shifted potential different than a reference potential of the reference electrode, wherein the electronics subsystem is configured to detect an impedance signal derived from two of the first working electrode, the second working electrode, the reference electrode, and the counter electrode in response to an applied voltage near the shifted potential; and

a processing subsystem in communication with the electronics subsystem and comprising: a first module configured to generate an analysis indicative of an analyte parameter of the user and derived from the signal stream and the impedance signal, and a second module configured to transmit information derived from the analysis to the user, thereby facilitating monitoring of body chemistry of the user.

17. The system ofclaim 16, further comprising an applicator configured to accelerate a portion of the housing, supporting the microsensor, toward skin of the user, thereby causing the microsensor to penetrate skin of the user and sensing regions of the microsensor to access interstitial fluid of the user.

18. The system ofclaim 17, wherein the housing comprises a first disposable portion that supports the microsensor and a first subset of the electronics subsystem including a multiplexer and an analog front end, and wherein the housing comprises a second reusable portion that supports a second subset of the electronics subsystem.

19. The system ofclaim 17, wherein the housing comprises a first disposable portion that supports the microsensor, and wherein the housing comprises a second reusable portion that supports the electronics subsystem.

20. The system ofclaim 17, wherein the housing, the microsensor, and the electronics subsystem are configured to be disposed after a lifetime usage of less than thirty days.

21. The system ofclaim 16, wherein the electronics subsystem is configured to apply the applied voltage, having a sinusoidal waveform with a characteristic value centered about the shifted potential, upon detection of a voltage condition at the counter electrode.

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