Electrodynamic field strength triggering system

Abstract

Systems and methods for automatically triggering wireless power and data exchange between an external reader and an implanted sensor. The implanted sensor may measure the strength of an electrodynamic field received wirelessly from the reader and convey field strength data based on the measured strength of the received electrodynamic field to the reader. If the field strength data indicates that the strength of an electrodynamic field received by the sensor is sufficient for the implanted sensor to perform an analyte measurement, the reader may convey an analyte measurement command to the sensor, which may execute the analyte measurement command and convey measurement information back to the reader. The systems and methods may trigger the analyte measurement as the reader transiently passes within sufficient range/proximity to the implant (or vice versa).

We claim: 
     
         1 . A method of triggering a sensor implanted within a living animal to measure a concentration of an analyte in a medium within the living animal, the method comprising:
 coupling an inductive element of an external reader and an inductive element of the sensor within an electrodynamic field;   generating field strength data indicative of the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor;   determining, based on the field strength data, whether the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor is sufficient for the sensor to perform an analyte concentration measurement and convey the results thereof to the external reader; and   if the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor is determined to be sufficient, triggering an analyte concentration measurement by the sensor and conveyance the results thereof to the external reader.   
     
     
         2 . The method of triggering of  claim 1 , wherein the external reader generates the field strength data by producing, using circuitry of the external reader, a coupling value proportional to the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor. 
     
     
         3 . The method of triggering of  claim 1 , further comprising producing, using circuitry of the sensor, a coupling value proportional to the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor. 
     
     
         4 . The method of triggering of  claim 3 , further comprising modulating, using circuitry of the sensor, the electrodynamic field based on the coupling value proportional to the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor;
 wherein the external reader generates the field strength data by decoding, using circuitry of the external reader, the modulation of the electrodynamic field.   
     
     
         5 . The method of triggering of  claim 3 , further comprising:
 converting, using circuitry of the sensor, the coupling value into a digital coupling value; and   modulating, using circuitry of the sensor, the electrodynamic field based on the digital coupling value;   wherein the external reader generates the field strength data by decoding, using circuitry of the external reader, the modulation of the electrodynamic field.   
     
     
         6 . The method of triggering of  claim 1 , wherein the field strength data is a value proportional to the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor. 
     
     
         7 . The method of triggering of  claim 6 , wherein determining whether the strength of the coupling is sufficient comprises comparing the field strength data to a field strength sufficiency threshold. 
     
     
         8 . The method of triggering of  claim 7 , wherein the strength of the coupling is determined to be sufficient if the field strength data exceeds a field strength sufficiency threshold. 
     
     
         9 . The method of triggering of  claim 1 , wherein triggering the analyte concentration measurement by the sensor and conveyance the results thereof to the external reader comprises conveying, using circuitry of the external reader, an analyte measurement command to the sensor. 
     
     
         10 . The method of triggering of  claim 9 , wherein conveying the analyte measurement command to the sensor comprises modulating, using circuitry of the external reader, the electrodynamic field. 
     
     
         11 . The method of triggering of  claim 10 , further comprising:
 decoding, using circuitry of the sensor, the modulation of the electrodynamic field by the circuitry of the external reader;   executing, using the sensor, the analyte measurement command, wherein the execution of the analyte measurement command comprises:
 generating, using the implanted sensor, analyte measurement information indicative of the concentration of the analyte in the medium within the living animal; and 
 conveying, using circuitry of the sensor, the generated analyte measurement information. 
   
     
     
         12 . The method of triggering of  claim 11 , wherein the conveying the generated analyte measurement information comprising modulating, using circuitry of the sensor, the electrodynamic field based on the generated analyte measurement information. 
     
     
         13 . The method of triggering of  claim 1 , wherein the coupling comprises moving the sensor and the external reader relative to each other such that the inductive element of the external reader and the inductive element of the sensor are coupled within the electrodynamic field. 
     
     
         14 . A method of triggering a sensor implanted within a living animal to measure a concentration of an analyte in a medium within the living animal, the method comprising:
 generating, using an external reader, field strength data indicative of the strength of coupling of an inductive element of the external reader and an inductive element of the sensor within an electrodynamic field;   determining, using the external reader, based on the field strength data, whether the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor is sufficient for the sensor to perform an analyte concentration measurement and convey the results thereof to the external reader;   if the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor is determined to be insufficient, repeating the generating and determining steps;   if the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor is determined to be sufficient, triggering, using the external reader, an analyte concentration measurement by the sensor and conveyance the results thereof to the external reader, wherein the triggering comprises conveying, using circuitry of the external reader, an analyte measurement command to the sensor; and   decoding, using circuitry of the external reader, analyte measurement information conveyed from the sensor.   
     
     
         15 . The method of triggering of  claim 14 , wherein the external reader generates the field strength data by producing, using circuitry of the external sensor, a coupling value proportional to the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor. 
     
     
         16 . The method of triggering of  claim 14 , wherein generating the field strength data comprises decoding, using circuitry of the external reader, field strength data conveyed from the sensor. 
     
     
         17 . The method of triggering of  claim 14 , wherein the decoding field strength data comprises decoding modulation of the electrodynamic field by the sensor. 
     
     
         18 . The method of triggering of  claim 14 , wherein the field strength data is a value proportional to the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor. 
     
     
         19 . The method of triggering of  claim 18 , wherein determining whether the strength of the coupling is sufficient comprises comparing the field strength data to a field strength sufficiency threshold. 
     
     
         20 . The method of triggering of  claim 19 , wherein the strength of the coupling is determined to be sufficient if the field strength data exceeds a field strength sufficiency threshold. 
     
     
         21 . The method of triggering of  claim 14 , wherein conveying the analyte measurement command to the sensor comprises modulating, using circuitry of the external reader, the electrodynamic field. 
     
     
         22 . The method of triggering of  claim 14 , wherein decoding the analyte measurement information conveyed from the sensor comprises decoding the analyte measurement information from modulation of the electrodynamic field by the sensor. 
     
     
         23 . The method of triggering  claim 14 , wherein the triggering comprises sending power to the sensor. 
     
     
         24 . The method of  claim 14 , wherein the coupling comprises sending power to the sensor. 
     
     
         25 . A method of triggering a sensor implanted within a living animal to measure a concentration of an analyte in a medium within the living animal, the method comprising:
 producing, using circuitry of the sensor, a coupling value proportional to the strength of the coupling of the inductive element of an external reader and an inductive element of the sensor within an electrodynamic field;   converting, using circuitry of the sensor, the coupling value into a digital coupling value;   conveying, using circuitry of the sensor, the digital coupling value to the external reader;   decoding, using the circuitry of the sensor, an analyte measurement command conveyed from the external reader;   executing, using the sensor, the analyte measurement command, wherein the execution of the analyte measurement command comprises:
 generating, using the sensor, analyte measurement information indicative of the concentration of the analyte in the medium within the living animal; and 
 conveying, using the inductive element of the implanted sensor, the analyte measurement information. 
   
     
     
         26 . The method of triggering of  claim 25 , wherein the conveying the digital coupling value comprises modulating, using circuitry of the sensor, the electrodynamic field based on the digital coupling value. 
     
     
         27 . The method of triggering of  claim 25 , wherein the conveying the analyte measurement information comprises modulating, using circuitry of the sensor, the electrodynamic field based on the analyte measurement information. 
     
     
         28 . The method of triggering of  claim 25 , wherein decoding the analyte measurement command comprises decoding the analyte measurement command from modulation of the electrodynamic field by the external reader. 
     
     
         29 . The method of triggering of  claim 25 , wherein the execution of the analyte measurement command comprises turning a light source of the implanted sensor on and off one or more times, wherein the light source is configured to, when turned on, to irradiate indicator molecules having an optical characteristic responsive to the concentration of the analyte with excitation light, the indicator molecules being configured to interact with the analyte in the medium within the living animal while the implanted sensor is implanted within the living animal. 
     
     
         30 . A sensor for implantation within a living animal and measurement of a concentration of an analyte in a medium within the living animal, the sensor comprising:
 (a) an inductive element configured to couple with an inductive element of an external reader within an electrodynamic field;   (b) an input/output circuit configured to:
 (i) produce a coupling value proportional to the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor within the electrodynamic field; 
 (ii) convey a digital coupling value to the external reader; 
 (iii) decode an analyte measurement command conveyed from the external reader; and 
 (iv) convey analyte measurement information indicative of the concentration of the analyte in the medium within the living animal; 
   (c) circuitry to convert the coupling value into a digital coupling value; and   (d) a measurement controller configured to:
 (i) control the input/output circuit to convey the digital coupling value; 
 (ii) in accordance with the analyte measurement command, generate the analyte measurement information indicative of the concentration of the analyte in the medium within the living animal; and 
 (iii) control the input/output circuit to convey the analyte measurement information. 
   
     
     
         31 . The sensor of  claim 30 , wherein the input/output circuit configured to convey the digital coupling value by modulating the electrodynamic field based on the digital coupling value. 
     
     
         32 . The sensor of  claim 30 , wherein the input/output circuit configured to convey the analyte measurement information by modulating the electrodynamic field based on the analyte measurement information. 
     
     
         33 . The sensor of  claim 30 , wherein the input/output circuit configured to decode the analyte measurement command by decoding the analyte measurement command from modulation of the electrodynamic field by the external reader. 
     
     
         34 . The sensor of  claim 30 , further comprising:
 indicator molecules having an optical characteristic responsive to the concentration of the analyte, the indicator molecules being configured to interact with the analyte in the medium within the living animal when the sensor is implanted within the living animal;   a first photodetector configured to output a first analog light measurement signal indicative of the amount of light received by the first photodetector;   a second photodetector configured to output a second analog light measurement signal indicative of the amount of light received by the second photodetector; and   a light source configured to emit excitation light to the indicator molecules;   wherein the measurement controller configured to control the light source in accordance with the analyte measurement command.   
     
     
         35 . An external reader for triggering a sensor implanted within a living animal to measure a concentration of an analyte in a medium within the living animal, the external reader comprising:
 (a) an inductive element configured to couple with an inductive element of an external reader within electrodynamic field; and   (b) circuitry configured to:
 (i) generate field strength data indicative of the strength of coupling of an inductive element of the external reader and an inductive element of the sensor within an electrodynamic field; 
 (ii) determine based on the field strength data, whether the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor is sufficient for the sensor to perform an analyte concentration measurement and convey the results thereof to the external reader; 
 (iii) if the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor is determined to be insufficient, repeat the generating and determining steps; 
 (iv) if the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor is determined to be sufficient, trigger an analyte concentration measurement by the sensor and conveyance the results thereof to the external reader, wherein the triggering comprises conveying an analyte measurement command to the sensor; and 
 (v) decode analyte measurement information conveyed from the sensor. 
   
     
     
         36 . The external reader of  claim 35 , wherein the circuitry is configured to generate the field strength data by producing a coupling value proportional to the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor. 
     
     
         37 . The external reader of  claim 35 , wherein the circuitry is configured to generate the field strength data by decoding field strength data conveyed from the sensor. 
     
     
         38 . The external reader of  claim 37 , wherein the circuitry is configured to decode the field strength data by decoding modulation of the electrodynamic field by the sensor. 
     
     
         39 . The external reader of  claim 35 , wherein the field strength data is a value proportional to the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor. 
     
     
         40 . The external reader of  claim 39 , wherein the circuitry is configured to determine whether the strength of the coupling is sufficient by comparing the field strength data to a field strength sufficiency threshold. 
     
     
         41 . The external reader of  claim 40 , wherein the circuitry is configured to determine the strength of the coupling to be sufficient if the field strength data exceeds a field strength sufficiency threshold. 
     
     
         42 . A method of triggering a sensor implanted within a living animal to measure a concentration of an analyte in a medium within the living animal, the method comprising:
 producing, using circuitry of the sensor, a coupling value proportional to the strength of the coupling of the inductive element of an external reader and an inductive element of the sensor within an electrodynamic field;   determining, using the sensor, based on the coupling value, whether the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor is sufficient for the sensor to perform an analyte concentration measurement and convey the results thereof to the external reader;   if the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor is determined to be sufficient, executing, using the sensor, the analyte measurement command, wherein the execution of the analyte measurement command comprises:
 generating, using the sensor, analyte measurement information indicative of the concentration of the analyte in the medium within the living animal; and 
 conveying, using the inductive element of the implanted sensor, the analyte measurement information. 
   
     
     
         43 . The method of  claim 42 , further comprising, if the strength of the coupling of the inductive element of the external reader and the inductive element of the sensor is determined to be insufficient, conveying, using circuitry of the sensor, field strength data to the external reader, wherein the field strength data comprises a digitized coupling value and/or an indication that the coupling is insufficient. 
     
     
         44 . The method of  claim 42 , wherein determining whether the strength of the coupling is sufficient comprises comparing the coupling value to a field strength sufficiency threshold. 
     
     
         45 . The method of  claim 44 , wherein the strength of the coupling is determined to be sufficient if the coupling value exceeds a field strength sufficiency threshold. 
     
     
         46 . An external reader for obtaining an analyte measurement from an implanted sensor, comprising:
 a housing;   reader components configured to wirelessly communicate with the implanted sensor and obtain an analyte measurement from the implanted sensor, wherein the reader components comprise a coil configured to inductively couple with the implanted sensor; and   a communication member configured to communicate the analyte measurement to an electronic device.   
     
     
         47 . The external reader of  claim 46 , wherein the communication member is configured to wirelessly transmit information to the electronic device. 
     
     
         48 . The external reader of  claim 46 , wherein the communication member is a pin configured to couple with a port in the electronic device. 
     
     
         49 . The external reader of  claim 46 , wherein the electronic device is a smartphone. 
     
     
         50 . The external reader of  claim 46 , wherein the reader components are configured to obtain the analyte measurement from the implanted sensor in less than one second. 
     
     
         51 . An external reader for obtaining analyte measurements from an implanted sensor and configured to encase a smartphone including a communication port, comprising:
 a first casing including a first coupling member;   a second casing including a second coupling member configured to couple with the first coupling member;   a communication member configured to couple with the communication port of the smartphone; and   reader components configured to wirelessly communicate with the implanted sensor and obtain an analyte measurement from the implanted sensor, wherein the reader components comprise a coil configured to inductively couple with the implanted sensor.   
     
     
         52 . The external reader of  claim 51 , wherein the communication member is a protrusion from the second casing. 
     
     
         53 . The external reader of  claim 51 , wherein the reader components are configured to obtain the analyte measurement from the implanted sensor in less than one second.