Patent attributes
A signal-to-noise ratio and measurement precision is increased in electrode units disposed on the left and right sides of a steering wheel. A plurality of electrode units is disposed in the left and right handholds of a steering wheel. The contact impedances of all the electrode units are measured. A pair of left and right electrode units to be used to measure an electrocardiographic signal is designated from among the electrode units whose measured contact impedances are less than or equal to a first threshold. The results of measurement of an electrocardiographic signal by the designated electrode units are added in order to minimize noise. An electrode unit with high contact impedance is used to measure induction noise and remove the induction noise component from the electrocardiographic signal measurement result.
