Provided is a technique for more accurately ascertaining a persons status. A three-layered structure is provided with a sensing mechanism section (230) disposed between a base cushion member (220) and a back-supporting cushion member (201) provided as a tension structure stretched on a back support section of a human body support mechanism, the base cushion member (220) and the back-supporting cushion member (201) being integrated together by a pouch member (210). A pelvic/lumbar support member (240) for urging a pelvic/lumbar support region of the back-supporting cushion member (201) is provided below the sensing mechanism section (230). The sensing mechanism section (230) is disposed between the base cushion member (220) and the back-supporting cushion member (201), and the cushion members therefore undergo tension in the surface direction. The back-supporting cushion member is provided so as to be stretched on the back support section of the human body support mechanism, whereby the sensing mechanism section (230) disposed on the backside of the back-supporting cushion member (201) is able to detect biological signals with high sensitivity.Linvention concerne une technique pour déterminer plus précisément létat dune personne. Une structure à trois couches comporte une section de mécanisme de détection (230) disposée entre un élément de coussin de base (220) et un élément de coussin de support de dos (201) prévu en tant que structure de tension étirée sur une section de support de dos dun mécanisme de support de corps humain, lélément de coussin de base (220) et lélément de coussin de support de dos (201) étant intégrés ensemble par un élément de poche (210). Un élément de support pelvien/lombaire (240) pour presser une région de support pelvienne/lombaire de lélément de coussin de support de dos (201) est disposé au-dessous de la section de mécanisme de détection (230). La section de mécanisme de détection (230) est disposée entre lélément de coussin de base (220