Methods, systems, and devices for calibration and optimization of glucose sensors and sensor output

A method for external calibration of a glucose sensor used for measuring a level of glucose in a body of a user, the glucose sensor including physical sensor electronics, a microcontroller, and a working electrode, the method comprising:

• accessing electrode current (Isig) signals for the working electrode, the Isig signals being measured by the physical sensor electronics;
• accessing Electrochemical Impedance Spectroscopy (EIS) related data for the working electrode, the EIS-related data generated by an EIS procedure;
• based on the Isig signals, the EIS-related data, and a plurality of calibration-free sensor glucose (SG)-predictive models, calculating, by the microcontroller, a respective SG value for each of the SG-predictive models;
• calculating, by the microcontroller, a modification factor based on a value of a physiological calibration factor (PCF), a value of an environmental calibration factor (ECF), or both;
• determining, by the microcontroller, whether the calculated modification factor is valid;
• and
• in a case where the modification factor is determined to be valid;
• calculating, by the microcontroller, a calibrated respective SG value for each of the SG-predictive models based on the modification factor and the respective SG value for the respective SG-predictive model;
• fusing, by the microcontroller, the calibrated SG values for the SG-predictive models to calculate a single, calibrated, fused SG value;
• performing, by the microcontroller, error detection diagnostics on the calibrated, fused SG value to determine whether a correctable error exists in the calibrated, fused SG value;
• and
• displaying the calibrated, fused SG value to the user,
• wherein the PCF is based on status information of an activity level, a heart rate, a blood pressure, and a body temperature of the user, and
• wherein, in a case where it is determined that the correctable error exists, the correctable error in the calibrated, fused SG value is corrected by the microcontroller.