Outcome valutativo in pazienti operati di artroprotesi d'anca: integrazione di pi sistemi

A flexible actuator 2 according to the invention includes a movable part 6, an actuator body 8, a reservoir 10, and a pump 12 that moves a liquid between the reservoir 10 and a main liquid chamber 4. The movable part 6 includes a long tube 16 that forms the main liquid chamber, frame members 18a, 18b . . . aligned at predetermined intervals along a length of the tube, and a core member 20 that holds the alignment of the frame members. The tube includes a narrow hollow portion 24 that communicates between flat expanded hollow portions 22a, 22b . . . . Among the plurality of expanded hollow portions, the expanded hollow portion at a base has a largest transverse cross sectional area, with transverse cross sectional areas of the expanded hollow portions gradually decreasing toward a tip, and the expanded hollow portion at the tip has a smallest transverse cross sectional area.