Patent ID: 9645103
Date: 2017-05-09
CPC Classifications: G01N

Claim:
1. An analyte sensor, comprising: a detection element comprising an analyte detecting portion which is monotonically changed in mass in response to adsorption of a target provided in an analyte or reaction with the target, the detection element configured to output a detection signal of AC responsive to mass variations in the analyte detecting portion; a reference element comprising a reference measuring portion which undergoes neither adsorption of the target nor reaction with the target, the reference element configured to output a reference signal of AC relative to the detection signal; a measurement portion which determines two candidate phase-change values of a positive candidate phase-change value and a negative candidate phase-change value, from a measurement signal which is obtained from the detection signal and the reference signal in accordance with a heterodyne system, the measurement portion configured to output the positive candidate phase-change value as a phase change value when measurement signal strength is decreased with time, and configured to output the negative candidate phase-change value as a phase change value when measurement signal strength is increased with time, in a case where a mass of the analyte detecting portion is monotonically increased and the detection signal is obtained by subtracting the detection signal from the reference signal in accordance with the heterodyne system, or where the mass of the analyte detecting portion is monotonically decreased and the detection signal is obtained by subtracting the reference signal from the detection signal in accordance with the heterodyne system, and the measurement portion configured to output the negative candidate phase-change value as a phase change value when measurement signal strength is decreased with time, and configured to output the positive candidate phase-change value as a phase change value when measurement signal strength is increased with time, in a case where the mass of the analyte detecting portion is monotonically increased and the detection signal is obtained by subtracting the reference signal from the detection signal in accordance with the heterodyne system, or where the mass of the analyte detecting portion is monotonically decreased and the detection signal is obtained by subtracting the detection signal from the reference signal in accordance with the heterodyne system; and a detection amount calculation portion which calculates a detection amount of the analyte on a basis of the phase change value.