PROBLEM TO BE SOLVED: To ensure substantially uniform rigidity in all radial directions while achieving a size reduction.SOLUTION: An ultrasonic surgical apparatus includes a polygonal columnar elastic body 11 that is formed of an elastic body and that has a substantially regular polygonal cross-section plate-like piezoelectric elements 12 that are secured to mutually opposing side surfaces of the polygonal columnar elastic body 11 and that are polarized in a plate-thickness direction a rod-like contactor 13 that is secured to an end of the polygonal columnar elastic body 11 and that has a smaller diameter than the polygonal-columnar elastic body 11 and a drive-pulse generating circuit that causes the rod-like contactor 13 to ultrasonically vibrate by generating a vertical vibration which expands/contracts the polygonal columnar elastic body 11 in the longitudinal direction by applying an AC voltage to the piezoelectric elements 12 in the plate-thickness direction.COPYRIGHT: (C)2013,JPO&INPIT【課題】小型化を図りつつ全ての径方向に略均等な剛性を確保する。【解決手段】弾性体からなり略正多角形断面を有する角柱状弾性体11と、角柱状弾性体11の相互に対向する側面に固定され、板厚方向に分極された板状の圧電素子12と、角柱状弾性体11の端部に固定され、角柱状弾性体11よりも小さな径の棒状接触子13と、圧電素子12に対して板厚方向に交番電圧を印加し、角柱状弾性体11に長手方向に伸縮する縦振動を発生させて棒状接触子13を超音波振動させる駆動パルス発生回路とを備える超音波外科手術装置を提供する。【選択図】図3
