A first vital signs information detecting sensor and a second vital signs information sensor are attached to a living body. The first vital signs information detecting sensor detects over time first vital signs information and first motion information of the living body. The first vital signs information and the first motion information are transmitted from the first vital signs information detecting sensor to a receiver. The second vital signs information detecting sensor detects over time second vital signs information and second motion information of the living body. The second vital signs information and the second motion information are transmitted from the second vital signs information detecting sensor to the receiver. The first vital signs information and the second vital signs information are displayed on a display of the receiver in a synchronized state, on the basis of the first motion information and the second motion information.