Embolic devices for occluding body lumens

An embolic device for placement in a body lumen, includes: an elongated member having a linear configuration when in room temperature, the elongated member being configured to form a first three-dimensional structure in response to body temperature; wherein the elongated member comprises a first segment, a second segment, and a third segment, the second segment being located between the first segment and the third segment; wherein the first segment and the third segment are configured to change their respective shapes in response to the body temperature; and wherein the second segment that is located between the first segment and the third segment has a shape that is independent of the body temperature.