Embolic devices for occluding body lumens

1. An embolic device for placement in a body lumen, the embolic device comprising:

an elongated member having a first configuration when at room temperature, the elongated member being configured to form a three-dimensional structure in response to body temperature, the three-dimensional structure having a second configuration that is different from the first configuration;

wherein the elongated member comprises a first segment, a second segment, and a third segment, the second segment being 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 first segment is martensitic when the first segment is at the room temperature, and is austenitic when the first segment is at the body temperature; and

wherein the second segment that is between the first and third segments is softer than the first and third segments.

2. The embolic device of claim 1 , wherein the first segment is configured to form a first part of a loop, and the third segment is configured to form a second part of the loop.

3. The embolic device of claim 1 , wherein the first segment is configured to form a first loop, and the third segment is configured to form a second loop.

4. The embolic device of claim 1 , wherein the first segment has a first length, the second segment has a second length, and the third segment has a third length; and

wherein the second length of the second segment is shorter than the first length of the first segment, and is also shorter than the third length of the third segment.

5. The embolic device of claim 1 , wherein the second segment comprises a martensitic segment.

6. The embolic device of claim 1 , wherein the second segment is martensitic when the second segment at the room temperature, and is martensitic when the second segment is at the body temperature.

7. The embolic device of claim 1 , wherein the three-dimensional structure comprises a plurality of loops, and wherein the first segment, the second segment, and the third segment are parts of one of the loops.

8. An embolic device for placement in a body lumen, the embolic device comprising:

an elongated member having a first configuration when at room temperature, the elongated member being configured to form a three-dimensional structure in response to body temperature, the three-dimensional structure having a second configuration that is different from the first configuration;

wherein the elongated member comprises a first segment, a second segment, and a third segment, the second segment being between the first segment and the third segment;

wherein the first segment is martensitic when the first segment is at the room temperature, and is austenitic when the first segment is at the body temperature; and

wherein the second segment is martensitic when the second segment is at the room temperature, and is also martensitic when the second segment is at the body temperature.

9. The embolic device of claim 8 , wherein the first segment is configured to form a first part of a loop, and the third segment is configured to form a second part of the loop.

10. The embolic device of claim 8 , wherein the first segment is configured to form a first loop, and the third segment is configured to form a second loop.

11. The embolic device of claim 8 , wherein the first segment has a first length, the second segment has a second length, and the third segment has a third length; and

wherein the second length of the second segment is shorter than the first length of the first segment, and is also shorter than the third length of the third segment.

12. The embolic device of claim 8 , wherein the three-dimensional structure comprises a plurality of loops, and wherein the first segment, the second segment, and the third segment are parts of one of the loops.

13. The embolic device of claim 8 , wherein the second segment comprises a martensitic segment.

14. An embolic device for placement in a body lumen, the embolic device comprising:

an elongated member having a first configuration when at room temperature, the elongated member being configured to form a three-dimensional structure in response to body temperature, the three-dimensional structure having a second configuration that is different from the first configuration;

wherein the elongated member comprises a first segment, a second segment, and a third segment, the second segment extending from an end of the first segment to an end of the third segment;

wherein the first segment and the third segment are configured to change their respective shapes in response to the body temperature;

wherein the first segment has a first length, the second segment has a second length that is an entire length of the second segment, and the third segment has a third length;

wherein an entirety of the first segment has a first material property, an entirety of the second segment has a second material property that is different from the first material property, and an entirety of the third segment has a third material property that is different from the second material property;

wherein the second length of the second segment is shorter than the first length of the first segment, and is also shorter than the third length of the third segment; and

wherein the first segment is martensitic when the first segment is at the room temperature, and is austenitic when the first segment is at the body temperature.

15. The embolic device of claim 14 , wherein the second length of the second segment is less than 50% of the first length of the first segment, and is also less than 50% of the third length of the third segment.

16. The embolic device of claim 14 , wherein the first material property is the same as the third material property.

17. The embolic device of claim 14 , wherein the second segment is martensitic when the second segment is at the room temperature, and is also martensitic when the second segment is at the body temperature.

18. The embolic device of claim 14 , wherein the first segment is configured to form a first part of a loop, and the third segment is configured to form a second part of the loop.

19. The embolic device of claim 14 , wherein the first segment is configured to form a first loop, and the third segment is configured to form a second loop.