PROBLEM TO BE SOLVED: To simply detect contact resistance between a measurement subjects scalp and a brain wave measuring electrode.SOLUTION: A contact resistance detector takes in a voltage drop detection signal Va generated at each of contact resistances Ra11 to Ra16 between a plurality of brain wave measuring electrodes CH1 to CH6 and a scalp 2X by individually supplying constant currents ia11 to ia16 to which different frequencies 24[Hz] to 34[Hz] are allocated to the brain wave measuring electrodes CH1 to CH6 during the same processing section T1 and extracts a voltage drop detection signal component of each of the brain wave measuring electrodes CH1 to CH6 on the basis of the allocated frequencies 24[Hz] to 34[Hz], making it possible to detect the contact resistances Ra11 to Ra16 with respect to the plurality of brain wave measuring electrodes CH1 to CH6 in a lump during the same processing section T1. Thereby, the contact resistances Ra11 to Ra16 of the plurality of brain wave measuring electrodes CH1 to CH6 can be simply detected in a unit time.SELECTED DRAWING: Figure 8COPYRIGHT: (C)2017,JPO&INPIT【課題】測定対象者の頭皮と脳波測定電極との間の接触抵抗を簡便に検出する。【解決手段】同じ処理区間T1の間に、複数の脳波測定電極CH1~CH6に対して異なる周波数24[Hz]~34[Hz]が割り当てられた定電流ia11~ia16をそれぞれ供給することにより当該脳波測定電極CH1~CH6と頭皮2Xとの間の接触抵抗Ra11~Ra16にそれぞれ生ずる電圧降下検出信号Vaを取り込むと共に、当該割り当てられた周波数24[Hz]~34[Hz]に基づいて各脳波測定電極CH1~CH6の電圧降下検出信号成分を抽出することにより、当該同じ処理区間T1の間に一挙に複数の脳波測定電極CH1~CH6ごとの接触抵抗Ra11~Ra16を検出することができ、これにより単時間の間に簡便に複数の脳波測定電極CH1~CH6の接触抵抗Ra11~Ra16を検出することができる。【選択図】図8
