PROBLEM TO BE SOLVED: To provide a technique for estimating an internal structure of a living body. SOLUTION: A contact pressure sensor having a plurality of cells, which is arranged between a pedestal and a living body, and a database storing a three-dimensional model relating to spatial coordinates of a bone shape and a skin surface shape of a living body in an unloaded state. From the receiving unit that receives the input of the pressure distribution data including the plane coordinates of the plurality of cells and the pressure data, the plane coordinates of the pressure distribution data, and the plane of the pressure distribution data among the spatial coordinates of the three-dimensional model. Estimating the distance information from the skin surface to the surface of the bone, which has different mechanical characteristics from the mapping unit that coordinates the coordinates corresponding to the coordinates and the surface of the bone and the skin, as the thickness of the soft tissue of the living body. And an output unit that outputs the shape of the skin surface, the thickness of the soft tissue of the living body, and the shape of the bone as the internal structure of the living body. [Selection diagram]【課題】 生体の内部構造を推定する技術を提供することにある。【解決手段】 無負荷状態での生体の骨の形状及び皮膚表面の形状の空間座標に関する三次元モデルを格納するデータベースと、台座と生体との間に配置され、複数のセルを有する接触圧センサから、前記複数のセルの平面座標及び圧力データを備える圧力分布データの入力を受付ける受付部と、前記圧力分布データの平面座標と、前記三次元モデルの空間座標のうち、前記圧力分布データの平面座標に相当する座標を位置合わせするマッピング部と、前記骨及び前記皮膚表面と力学特性が異なる、前記皮膚表面から前記骨の表面までの距離情報を、前記生体の軟部組織の厚みとして推定する推定部と、前記皮膚表面の形状、前記生体の軟部組織の厚み、及び、前記骨の形状を前記生体の内部構造として出力する出力部を、備える。【選択図】 図１
