Bio-signal analyzer, sheets and biological signal analysis method

There are provided a bio-signal analyzer using a sensor capable of detecting, even though it is non-invasive, a more prominent bio-signal, and a seat using the bio-signal analyzer. Air cushions (10), which are sensors detecting a bio-signal in a non-invasive manner, are disposed at the positions corresponding respectively to left and right iliocostalis lumborum muscles of a person, in a substantially vertically long state along the iliocostalis lumborum muscles, with upper ends thereof being set at least at the height corresponding to a lower face of a human diaphragm. In the diaphragm, bio-signals such as heartbeats, breaths, or pulsations of aorta passing through the vicinity of the diaphragm are resonated and amplified. Further, the iliocostalis lumborum muscles are at positions where they are easily vibrated by pulsations of aorta passing through the vicinity of the lumbar region. Therefore, by disposing the air cushions (10) as described above, bio-signals amplified by the diaphragm and the iliocostalis lumborum muscles can be detected.