FIELD: medicine.
SUBSTANCE: group of inventions relates to medicine and namely to the electronics unit and the system for determining the properties of the biosensor in vivo. The biosensor, when interacting with the electronic unit, electrochemically determines the value of the analyte in the sample of physiological fluid and contains a working electrode. The working electrode is covered with a membrane and contains an enzyme to ensure the reaction with an analyte. The working electrode has an electrical capacity. The membrane has electrical resistance. The electronics unit is configured to measure the raw current and the current characteristic showing the conductivity of the biosensor. When using the method, the relationship between the sensitivity and the conductivity of the biosensor is ensured. The raw current in the biosensor is measured. The current characteristic is measured under in vivo conditions showing the conductivity of the biosensor under in vivo conditions. In this case, the current characteristic is measured under in vivo conditions at the first operating point and at the second operating point. The operating points are selected in relation to the time constant τ. The time constant τ is determined by the electrical capacity C of the working electrode and the electrical resistance RM of the membrane according to the following formula τ = RM⋅C. The first operating point is chosen below τ, and the second operating point is chosen above τ. The analyte value is determined in the physiological fluid sample by using the raw current and compensating the sensitivity drift in the biosensor in vivo. This drift of the biosensor in vivo is compensated for using the measured raw current value and the corrected sensitivity value. The corrected sensitivity value is determined using the relationship between sensitivity and conductivity provided earlier. The fail-safe performance of the biosensor is controlled. It’s necessary to use the in vivo current characteristic measured at the first operating point and at the second operating point. The system for biosensor operation consists of a biosensor and an electronics unit. The electronics unit contains a unit for measuring the response to potential spread. The response measuring unit is designed to measure a current characteristic showing the conductivity of the biosensor. The response measuring unit contains a charge counter and a peak detector. The peak detector is configured to measure the current characteristic in vivo at the first operating point. The charge counter is configured to measure the current characteristic in vivo at the second operating point.
EFFECT: measurement of the current characteristic at 2 operating points chosen with regard to the time constant τ, which is determined by electrical capacity of the working electrode and the electrical resistance of the membrane as well as the use of a combination of compensation for the sensitivity drift in the biosensor in vivo and monitoring the fail-safe operation of the biosensor, more accurate determination of the analyte value based on the raw current is achieved.
13 cl, 9 dwg
