System for monitoring body chemistry

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.

We claim: 
     
         1 . A system for monitoring body chemistry of a user, the system comprising:
 a first housing portion supporting a microsensor comprising a working electrode, a reference electrode, and a counter electrode defined on a substrate and collectively operable to sense an analyte within interstitial fluid of the user during use, the first housing portion comprising:
 an opening into an electrical interface with the microsensor, and 
 an adhesive region, surrounding the microsensor at a second surface opposing the electrical interface, the adhesive region coupleable to skin of the user, 
   a second housing portion insertable into the opening of the first housing portion in a first configuration, the second housing portion supporting:
 an electronics subsystem comprising a signal conditioning portion that receives and processes a signal stream from the microsensor upon sensing of the analyte in a sensing mode, the signal conditioning portion configured with an operating potential at a shifted potential different than a reference potential of the reference electrode, wherein, during operation, the electronics subsystem repeatedly transitions between the sensing mode and an impedance detection mode, wherein in the impedance detection mode, the electronics subsystem:
 applies a voltage near the shifted potential to the working electrode, and 
 measures an impedance signal between the working electrode and the reference electrode; and 
 
   an applicator operable to accelerate and expel the second housing portion and the first housing portion from the applicator and onto the user, with the adhesive region and a filament array of a microsensor oriented toward skin of the user, thereby coupling the first and the second housing portions to the user and causing the microsensor to penetrate skin of the user prior to coupling of the adhesive region to the user.   
     
     
         2 . The system of  claim 1 , wherein during the sensing mode, the electronics subsystem continuously detects a voltage parameter of the counter electrode and, in cooperation with a processing system:
 generates a comparison between the voltage parameter and a voltage threshold condition, and   applies the applied voltage in the impedance detection mode based upon the comparison.   
     
     
         3 . The system of  claim 1 , further comprising a processing subsystem in communication with the electronics subsystem and operable in: a first mode that generates an analysis indicative of an analyte parameter of the user and derived from the signal stream and the impedance signal, and a second mode that render information derived from the analysis at an electronic device associated with the user, thereby facilitating monitoring of body chemistry of the user. 
     
     
         4 . The system of  claim 1 , wherein, in the impedance detection mode, the electronics subsystem applies the voltage having a characteristic value centered about the shifted potential and a sinusoidal waveform, upon detection of a voltage condition at the counter electrode. 
     
     
         5 . The system of  claim 1 , further comprising a processing system in communication with the electronics subsystem and an electronic device of the user, wherein, in relation to transitioning between the sensing mode and the impedance detection mode, the processing subsystem generates a notification at the electronic device of the user in response to detection of unsuitable impedance derived from a comparison between the impedance signal and an impedance threshold condition. 
     
     
         6 . The system of  claim 1 , wherein in relation to transitioning between the sensing mode and the impedance detection mode, an actuator coupled to the electronics subsystem automatically provides a vibrational force 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 post an initial application of the microsensor into the user. 
     
     
         7 . The system of  claim 1 , further comprising a reused mode wherein the first housing portion is disposed and uncoupled from the second housing portion, and wherein the second housing portion is coupled to a second instance of the first housing portion. 
     
     
         8 . A system for monitoring body chemistry of a user, the system comprising:
 a first housing portion supporting a microsensor comprising a working electrode, a reference electrode, and a counter electrode defined on a substrate and collectively operable to sense an analyte within interstitial fluid of the user during use, the first housing portion comprising:
 an opening into an electrical interface with the microsensor, and 
 an adhesive region, surrounding the microsensor at a second surface opposing the electrical interface, the adhesive region coupleable to skin of the user; and 
   a second housing portion insertable into the opening of the first housing portion in a first configuration, the second housing portion supporting:
 an electronics subsystem comprising a signal conditioning portion that receives and processes a signal stream from the microsensor upon sensing of the analyte in a sensing mode, the signal conditioning portion configured with an operating potential at a shifted potential different than a reference potential of the reference electrode, wherein, during operation, the electronics subsystem repeatedly transitions between the sensing mode and an impedance detection mode, wherein in the impedance detection mode, the electronics subsystem:
 applies a voltage near the shifted potential to an electrode subset comprising at least one the working electrode and the counter electrode, and 
 measures an impedance signal between the electrode subset and the reference electrode. 
 
   
     
     
         9 . The system of  claim 8 , wherein during the sensing mode, the electronics subsystem continuously detects a voltage parameter of the counter electrode and, in cooperation with a processing system:
 generates a comparison between the voltage parameter and a voltage threshold condition, and   applies the applied voltage in the impedance detection mode based upon the comparison.   
     
     
         10 . The system of  claim 8 , wherein the microsensor comprises a second working electrode defined on the substrate. 
     
     
         11 . The system of  claim 8 , further comprising a reused mode wherein the first housing portion is disposed and uncoupled from the second housing portion, and wherein the second housing portion is coupled to a second instance of the first housing portion. 
     
     
         12 . The system of  claim 8 , wherein the microsensor comprises an array of microfilaments, each filament in the array comprising i) a substrate core extending from the substrate and comprising a columnar protrusion having a base end and a distal portion operable to provide access to interstitial fluid of the user during use; ii) a conductive layer, isolated to the distal portion of the substrate core and away from the base end and operable to transmit electronic signals generated upon detection of the analyte; iii) an insulating layer surrounding the substrate core and exposing a portion of the conductive layer at the distal portion; and iv) a sensing layer coupled to the conductive layer and operable to sense the analyte. 
     
     
         13 . The system of  claim 12 , wherein the the microsensor comprises a selective layer, having a distribution of molecules that interact with the analyte, coupled to the sensing layer. 
     
     
         14 . The system of  claim 8 , wherein at least one of the microsensor and the electronics subsystem comprises a temperature sensor operable to measure body temperature of the user during use of the system. 
     
     
         15 . The system of  claim 8 , further comprising a processing subsystem in communication with the electronics subsystem and operable in: a first mode that generates an analysis indicative of an analyte parameter of the user and derived from the signal stream and the impedance signal, and a second mode that render information derived from the analysis at an electronic device associated with the user, thereby facilitating monitoring of body chemistry of the user. 
     
     
         16 . The system of  claim 15 , further comprising: at the processing subsystem, 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 value within a time duration at which values of the analyte parameter are within a target range, wherein the values of the analyte parameter comprise future state values of the analyte parameter. 
     
     
         17 . The system of  claim 8 , wherein the electrical interface of the first housing portion comprises a set of concentric ring contacts configured to interface electronics of the second housing portion with filaments of the microsensor, in any rotated configuration of the second housing portion within the opening of the first housing portion. 
     
     
         18 . The system of  claim 8 , further comprising a charging and data transfer mode, wherein transitioning to the charging and data transfer mode is triggered upon positioning the second housing portion, with the electronics subsystem into proximity with a base station, wherein, in the charging and data transfer mode, a battery of the electronics subsystem is charged by the base station and data is transferred between the electronics subsystem and a mobile computing device associated with the user. 
     
     
         19 . The system of  claim 8 , further comprising an applicator operable to accelerate and expel the second housing portion and the first housing portion from the applicator and onto the user, with the adhesive region and a filament array of a microsensor oriented toward skin of the user, thereby coupling the first and the second housing portions to the user and causing the microsensor to penetrate skin of the user prior to coupling of the adhesive region to the user. 
     
     
         20 . The system of  claim 19 , wherein accelerating the second housing portion and the first housing portion comprises, in response to a user interacting with a trigger of an applicator, transitioning a plunger of the applicator from a resting state to a loaded configuration with the plunger contacting the second housing portion, and releasing the plunger to accelerate the second housing portion toward skin of the user along a first axis perpendicular to the skin of the user, wherein the applicator and the plunger are arranged exterior the first and the second housing, and wherein the applicator surrounds the first and the second housing portion.