PROBLEM TO BE SOLVED: To provide an electrode unit which prevents the electrode part from moving relative to a blood vessel even when the lead part is moved due to body motion, while maintaining the operability when the electrode part is indwelled.SOLUTION: The electrode unit 1 comprises: a fixing part 10 formed from an elastic material and energizing an inner surface of a blood vessel when indwelled within the blood vessel with the fixing part being elastically deformed； at least one pair of electrode parts 20 mounted to the fixing part； and a linearly formed lead part 30, a tip part thereof being secured to the fixing part. The lead part has a soft region 31 formed therein, the soft region transferring only an elastic force of the magnitude which does not cause the fixing part to be moved relative to a blood vessel though the elastic region itself is deformed. In the lead part also, a housing part 35 into which a stylet 50 is insertible is formed on a tip side of a range where the soft region is arranged in the axial direction C of the lead part.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2016,JPO&INPIT【課題】置時の操作性を維持しつつ、リード部が体動により動いた場合でも血管に対して電極部が動くのを抑えた電極ユニットを提供する。【解決手段】電極ユニット１は、弾性を有する材料で形成され、弾性的に変形された状態で血管内に留置されることで血管の内面を付勢する固定部１０と、固定部に設けられた少なくとも一対の電極部２０と、線状に形成され先端部が固定部に取付けられたリード部３０と、を備え、リード部には、自身が変形しても血管に対して固定部を移動させない大きさの弾性力しか伝達しない軟性領域３１が形成され、リード部には、リード部の軸線Ｃ方向において軟性領域が設けられた範囲の先端側にスタイレット５０挿通可能な収容部３５が形成されている。【選択図】図１
