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 linear configuration when at 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;

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;

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 in response to the body temperature.

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, in response to the body temperature.

4. The embolic device of claim 1 ,

wherein the elongated member has a distal end and a proximal end opposite from the distal end, and wherein the embolic device further comprises a fourth segment that includes the proximal end; and

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

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

6. 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.

7. The embolic device of claim 6 , wherein the elongated member further comprises a fourth segment, a fifth segment, and a sixth segment that are parts of another one of the loops;

wherein the fifth segment is between the fourth segment and the sixth segment;

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

wherein the fifth segment that is located between the fourth segment and the sixth segment has a shape that is independent of the body temperature.

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

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 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, and wherein the second segment comprises an irreversible martensitic segment.

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, in response to the body temperature.

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, in response to the body temperature.

11. The embolic device of claim 8 ,

wherein the second segment extends from the first segment to the third segment, 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; 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 11 , wherein the second length of the second segment that is between the first segment and the third 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.

13. The embolic device of claim 8 ,

wherein the elongated member has a distal end and a proximal end opposite from the distal end, and wherein the embolic device further comprises a fourth segment that includes the proximal end; and

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

14. 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.

15. The embolic device of claim 14 , wherein the elongated member further comprises a fourth segment, a fifth segment, and a sixth segment that are parts of another one of the loops;

wherein the fifth segment is between the fourth segment and the sixth segment;

wherein the fourth segment and the sixth segment are martensitic when the fourth segment and the sixth segment are at the room temperature, and are austenitic when the fourth segment and the sixth segment are at the body temperature; and

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

16. A method of occluding a body lumen performed by an embolic device having an elongated member, the elongated member comprising a first segment, a second segment, and a third segment, wherein the second segment is between the first segment and the third segment, the method comprising:

undergoing a first shape change by the first segment of the elongated member in response to body temperature;

undergoing a second shape change by the second segment of the elongated member in response to force, wherein the second segment comprises an irreversible martensitic segment; and

undergoing a third shape change by the third segment of the elongated member in response to the body temperature;

wherein the second segment underwent the second shape change in response to force after the first segment is subject to the body temperature, and before the third segment is subject to the body temperature;

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.