Patent ID: 8869585
Filing Date: 2014-10-28
Classification: A61B

Abstract:
1. A method of calibrating a sensor for measuring an analyte in a patient monitoring system, the method comprising: calculating a predictable sensor drift; calibrating the sensor using at least one calibration fluid; periodically updating the sensor calibration coefficients using the predicted sensor drift only, providing the sensor with a first fluid comprising a predetermined concentration of an analyte; performing a first measurement of the analyte concentration in the first fluid with the sensor; providing the sensor with a further fluid comprising a further predetermined concentration of an analyte; performing at least one additional measurement of the further analyte concentration in the further fluid with the sensor after a predetermined time period; wherein the step of calculating the predictable sensor drift comprises calculating said drift from the difference between the first measured analyte concentration and the further measured analyte concentration, wherein the patient monitoring system comprises means for adjusting a gas concentration in the system, and wherein the analyte is said gas, the method further comprising: maintaining a well-defined concentration of the gas in the first fluid with said means for adjusting a gas concentration during the first measurement and the further measurement, wherein one of the first fluid and the further fluid comprises the patient's blood.