Patent Document ID: 20170328861
Application ID: 15666887
Patent Flag: 0

Claim One:
1. A method of performing real-time sensor diagnostics on a subcutaneous or implanted sensor of a sensor system, said sensor including at least one working electrode and said sensor system including a microprocessor that is operatively connected to said sensor, the method comprising: (a) periodically performing an electrochemical impedance spectroscopy (EIS) procedure to generate multiple sets of impedance-related data for said at least one working electrode; (b) calculating, by said microprocessor, respective values of a plurality of impedance-related parameters based on said multiple sets of impedance-related data, said plurality of parameters including impedance, phase angle, and Nyquist slope; and (c) based on said respective values, determining, by said microprocessor, whether the sensor is functioning normally, wherein the microprocessor: (i) performs a first test based on values of real impedance or phase angle; (ii) performs a second test based on values of respective frequencies at which successive EIS procedures are performed; (iii) performs a third test based on a comparison of current and post-sensor initialization impedance values at 1 kHz; (iv) performs a fourth test based on the value of post-sensor initialization impedance at 0.1 Hz; (v) performs a fifth test based on the global change in the value of Nyquist slope between 0.1 Hz and 1 Hz; (vi) performs a sixth test based on the change, over time, in the magnitude of real impedance; and (vii) determines that the sensor is functioning normally if at least 3 of said first through sixth tests are satisfied by generating results that fall within respective predetermined criteria.