Non-steady-state determination of analyte concentration for continuous glucose monitoring by potential modulation

A continuous glucose monitoring (CGM) device comprising:

• a wearable portion comprising:
• a sensor configured to produce current signals from interstitial fluid;
• a processor;
• a memory coupled to the processor;
• and
• transmitter circuitry coupled to the processor,
• wherein the memory of the CGM device includes a connection function based on measurements of primary current signals generated by application of a constant voltage potential applied to a reference sensor, and measurements of a plurality of probing potential modulation current signals generated by application of a probing potential modulation sequence applied between primary current signal measurements,
• wherein the application of the probing potential modulation sequence comprises applying a plurality of voltage potentials in sequence, each of the plurality of voltage potentials applied at a distinct time period during a glucose monitoring period, and
• wherein the memory includes computer program code stored therein that, when executed by the processor, causes the CGM device to:
• measure and store a primary current signal using the sensor and the memory of the wearable portion;
• measure and store the plurality of probing potential modulation current signals associated with the primary current signal,
• wherein the plurality of probing potential modulation current signals comprises a first output current measured at a start of the distinct time period for applying each of the plurality of voltage potentials and a second output current measured at an end of the distinct time period for applying each of the plurality of voltage potentials such that a plurality of first output currents and a plurality of second output currents are measured for the plurality of voltage potentials;
• determine an initial glucose concentration based on a conversion function and one of the plurality of measured probing potential modulation current signals;
• determine a connection function value based on the primary current signal and the plurality of measured probing potential modulation current signals,
• wherein the connection function value is determined based at least partially on a ratio of each of the plurality of second output currents relative to one of the plurality of first output currents measured at the start of the distinct time period during which each of the plurality of second output currents was measured;
• and
• determine a final glucose concentration based on the initial glucose concentration and the connection function value.

A method of determining glucose values during continuous glucose monitoring (CGM) comprising:

• providing a CGM device including a sensor, a memory, and a processor;
• applying a constant voltage potential to the sensor during the continuous glucose monitoring,
• wherein the continuous glucose monitoring comprises a plurality of distinct time periods;
• measuring a primary current signal resulting from the constant voltage potential and storing the primary current signal in the memory;
• applying a probing potential modulation sequence to the sensor,
• wherein applying the probing potential modulation sequence further comprises:
• applying a first voltage potential at a first distinct time period, and
• applying a second voltage potential at a second distinct time period immediately subsequent to the first distinct time period;
• measuring probing potential modulation current signals resulting from the probing potential modulation sequence and storing measured probing potential modulation current signals in the memory,
• wherein measuring the probing potential modulation current signals further comprises:
• measuring a first probing current during the first distinct time period for applying the first voltage potential, and
• measuring a second probing current during the second distinct time period for applying the second voltage potential;
• determining a conversion function value based on one of the measured probing potential modulation current signals;
• determining an initial glucose concentration based on the conversion function value;
• determining a connection function value based on the primary current signal and the measured probing potential modulation current signals,
• wherein the connection function value is determined based at least partially on a ratio of the second probing current relative to the first probing current;
• and
• determining a final glucose concentration based on the initial glucose concentration and the connection function value.