PROBLEM TO BE SOLVED: To reduce influence of polarization generated when a practical electrode is used without any limit on the frequency of applied voltage, and without any increase in a circuit scale and the number of parts.SOLUTION: A measuring electrode 24 includes a first electrode 24a and a second electrode 24b, and detects skin electric activity of a measurement object 21 according to a DC signal from a DC power supply 22. A polarity switching part 25 is constituted by the DC power supply 22 and a plurality of switches connected to the first electrode 24a and the second electrode 24b to form a first signal path in which a signal flows through the DC power supply 22, the first electrode 24a, the second electrode 24b, and an amplifier 23 in order and a second signal path in which a signal flows through the DC power supply 22, the second electrode 24b, the first electrode 24a, and the amplifier 23 in order. The first signal path and the second signal path are switched in a predetermined cycle by selecting the plurality of switches.COPYRIGHT: (C)2014,JPO&INPIT【課題】実用的な電極を用いたときに発生する分極による影響を、印加電圧の周波数の制限なく、回路規模や部品点数を増大させることなく低減すること。【解決手段】測定電極24は、第1の電極24aと第2の電極24bとを備え、直流電源22からの直流信号により測定対象物21の皮膚電気活動を検知する。極性切替部25は、直流電源22と第1の電極24a及び第2の電極24bに接続された複数のスイッチから構成され、複数のスイッチを切り替えることにより、直流電源22と第1の電極24aと第2の電極24bと増幅器23の順に信号が流れる第1の信号経路と、直流電源22と第2の電極24bと第1の電極24aと増幅器23の順に信号が流れる第2の信号経路とを構成して、第1の信号経路と第2の信号経路とを所定の周期で切り替える切り替え動作を行う。【選択図】図5
