Optional sensor calibration in continuous glucose monitoring

US11213230B2 · kind B2 · utility

Assignee

• MEDTRONIC MINIMED, INC. · US

Inventors

• Jeffrey Nishida · Los Angeles, US
• Andrea Varsavsky · Santa Monica, US
• Taly G. Engel · Los Angeles, US
• Keith Nogueira · Mission Hills, US
• Andy Y. Tsai · Pasadena, US
• Peter Ajemba · Humphreys, US

Key dates

• Filing date: Dec 13, 2017
• Grant date: Jan 4, 2022
• Expiry date: Dec 10, 2038

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/327
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method for optional external calibration of a calibration-free glucose sensor uses values of measured working electrode current (Isig) and EIS data to calculate a final sensor glucose (SG) value. Counter electrode voltage (Vcntr) may also be used as an input. Raw Isig and Vcntr values may be preprocessed, and low-pass filtering, averaging, and/or feature generation may be applied. SG values may be generated using one or more models for predicting SG calculations. When an external blood glucose (BG) value is available, the BG value may also be used in calculating the SG values. A SG variance estimate may be calculated for each predicted SG value and modulated, with the modulated SG values then fused to generate a fused SG. A Kalman filter, as well as error detection logic, may be applied to the fused SG value to obtain a final SG, which is then displayed to the user.