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 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, and 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 module configured to receive and process a signal stream from the microsensor upon sensing of the analyte; 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.   
     
     
         2 . The system of  claim 1 , further comprising a flexible cover coupled to the adhesive region. 
     
     
         3 . The system of  claim 1 , wherein the microsensor comprises a first working electrode, a second working electrode, a reference electrode, and a counter electrode, and is operable to provide an impedance signal, from two of the first working electrode, the second working electrode, the reference electrode, and the counter electrode, in response to application of an applied voltage, near a shifted potential different than a reference potential of the reference electrode, by the electronics subsystem. 
     
     
         4 . The system of  claim 1 , wherein the microsensor comprises an array of microfilaments, each filament in the array comprising i) a substrate core 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. 
     
     
         5 . The system of  claim 4 , wherein the array comprises a microfilament density that, in combination with acceleration of the first housing portion toward skin of the user, promotes penetration of the array into skin of the user. 
     
     
         6 . The system of  claim 1 , wherein the first housing portion includes a seal about a perimeter of the opening, the seal configured to seal a cap between the first housing portion and the second housing portion. 
     
     
         7 . The system of  claim 6 , wherein the seal comprises an o-ring at least partially molded with material of the first housing portion about the perimeter of the opening. 
     
     
         8 . The system of  claim 1 , 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. 
     
     
         9 . The system of  claim 1 , wherein the electrical interface of the first housing portion comprises a set of concentric ring contacts in communication with the microsensor. 
     
     
         10 . The system of  claim 9 , wherein the electronics subsystem of the second housing portion comprises a set of pins operable to contact the set of concentric ring contacts, in any rotated configuration of the second housing portion within the opening of the first housing portion, in the first configuration. 
     
     
         11 . The system of  claim 1 , wherein the electronics subsystem of the second housing portion comprises an antenna coupled to the user by way of the second housing portion and operable to transmit signals derived from the microsensor while coupled to the user. 
     
     
         12 . The system of  claim 1 , further comprising a processing subsystem in wireless communication with the electronics subsystem and operable to generate an analysis indicative of an analyte parameter of the user and derived from the signal stream and to render information derived from the analysis at a display of an electronic device associated with the user. 
     
     
         13 . A method for monitoring body chemistry of a user, the method comprising:
 providing a first housing portion supporting a microsensor operable to sense an analyte within interstitial fluid of the user, the first housing portion comprising a) an opening into an electrical interface with the microsensor, and b) an adhesive region, surrounding the microsensor at a second surface opposing the electrical interface;   receiving a second housing portion into the opening of the first housing portion, the second housing portion supporting an electronics subsystem configured to contact the electrical interface and receive a signal stream from the microsensor;   with an applicator, accelerating the second housing portion and the first housing portion toward skin of the user, thereby expelling the first and the second housing portions from the applicator, establishing electrical communication between the electronics subsystem and the electrical interface, delivering the microsensor into interstitial fluid of the user, and coupling the adhesive region of the first housing portion to the user.   
     
     
         14 . The method of  claim 13 , further including generating an impedance signal, from two of a first working electrode, a second working electrode, a reference electrode, and a counter electrode of the microsensor, upon application of an applied voltage, near a shifted potential different than a reference potential of the reference electrode. 
     
     
         15 . The method of  claim 14 , further comprising: by way of the electronics subsystem and a processing subsystem in communication with the electronics subsystem, substantially continuously detecting a voltage parameter of the counter electrode of the microsensor, and applying the applied voltage to generate the impedance signal whenever the voltage parameter of the counter electrode satisfies a voltage threshold condition 
     
     
         16 . The method of  claim 14 , further comprising: 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.   
     
     
         17 . The method of  claim 16 , wherein the electronics subsystem of the second housing portion comprises an antenna, and wherein transmitting comprises transmitting signals through the antenna with the second housing portion coupled to the user. 
     
     
         18 . The method of  claim 13 , further comprising delivering a flexible cover, coupled to the adhesive region of the first housing portion, from the applicator. 
     
     
         18 . The method of  claim 14 , further including providing a temperature sensor coupled to the electronics subsystem, receiving a skin temperature time series of data from the temperature sensor, and adjusting operation of the electronics subsystem based upon the skin temperature time series of data. 
     
     
         19 . The method of  claim 13 , wherein accelerating the second housing portion and the first housing portion toward skin of the user 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. 
     
     
         20 . The method of  claim 19 , wherein releasing the plunger comprises accelerating the adhesive region toward skin of the user, and causing microfilaments of the microsensor surrounded by the adhesive region to penetrate skin of the user.