Deformable breaking member having multiple contact portions

A medical device configured to be inserted into a body lumen to break an object in the body lumen, the medical device comprising:

• an elongated shaft configured to be rotatably driven;
• a deformable breaking member formed from a plurality of wires, and wherein the breaking member including proximal-side end portions of the plurality of wires arranged in the circumferential direction to form a sliding portion configured to be slidable with respect to and movable along the elongated shaft and distal-side end portions of the plurality of wires are arranged in the circumferential direction to form a fixing portion that is fixed to the elongated shaft;
• each of the plurality of wires including a first contact portion and a second contact portion, the first contact portion including a first convex portion and a second concave portion and the second contact portion including a third convex portion being at a position that is not a position where the proximal-side end portions of each of the plurality of wires are arranged in the circumferential direction to form the sliding portion and not at a position where the distal-side end portions of each of the plurality of wires are arranged in the circumferential to form the fixed portion, and wherein the first contact portion is distal of the second contact portion;
• wherein the first convex portion and the third convex portion project on a same side, and the second concave portion projects on an opposite side with respect to the first convex portion and the third convex portion;
• the first contact portion being located to be closer to a center portion of the breaking member in an axial direction of the breaking member than the second contact portion in a state in which the breaking member is expanded radially outward;
• and
• wherein the first contact portion includes a third contact portion and a fourth contact portion, the third contact portion being proximal to the fourth contact portion, and wherein the third contact portion and the fourth contact portion are located more radially outward than the second contact portion in a state in which the breaking member is expanded radially outward, and an outermost vertex of the breaking member in a radial direction is located in the third contact portion.