Embolic filters with a distal loop or no loop
The invention provides a device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient's body, comprising a filter element and a self-expanding radial element associated with the filter element. The filter element is expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained. The filter element comprises a self-expanding material having pores. The filter element has proximal and distal portions and a central portion, and has a shape in the expanded configuration which defines a cavity having a proximal facing opening. The self-expanding radial element is distal of the filter element, and the self-expanding radial element is adapted to maintain the filter element centered in the lumen.
1. A device for filtering emboli from blood flowing through a lumen defined by walls of a vessel in a patient's body, comprising:
an elongate support member;
a filter element carried on and attached to the elongate support member, the filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein the filter element comprises a self-expanding filter mesh material having pores, wherein the filter element has proximal and distal portions and a central portion, the filter element having a shape in the expanded configuration which defines a cavity having a proximal facing opening; and
a self-expanding radial element associated with the filter element, wherein the self-expanding radial element is distal of the filter element, and the self-expanding radial element is adapted to maintain the filter element centered in the lumen, the filter element being attached to the self-expanding radial element by a sliding element positioned between the filter element and the self-expanding radial element, the sliding element being slidable in relation to the elongate support member.
2. A device of claim 1 , wherein the self-expanding radial element comprises a loop, and wherein the loop is generally circular in shape.
3. A device of claim 2 , wherein the self-expanding radial element has one loop.
4. A device of claim 2 , wherein the self-expanding radial element comprises two or more loops.
5. A device of claim 4 , wherein the self-expanding radial element has two loops.
6. A device of claim 1 , wherein the filter element is attached to the elongate support member at the distal portion of the filter element.
7. A device of claim 6 , wherein the elongate support member is attached to the filter element at the proximal portion of the filter element.
8. A device of claim 1 , wherein the self-expanding radial element is adapted to not significantly impede the flow of blood through the lumen.
9. A device of claim 1 , wherein the device does not comprise any other self-expanding elements other than the self-expanding filter mesh material having pores and the self-expanding radial element.
10. A device of claim 1 , wherein the self-expanding radial element is made of nitinol wire.
11. A device of claim 1 , wherein when the self-expanding radial element is in its expanded configuration, the self-expanding radial element generally defines a plane substantially perpendicular to the elongate support member.
12. A device of claim 1 , wherein when the filter element is in the expanded configuration, the average pore size is from 30 to 300 microns and the standard deviation of the pore size is less than 20 percent of the average pore size.
13. A device of claim 1 , wherein when the filter element is in the expanded configuration, the filter element has a percent open area greater than 50 percent.
14. A device of claim 1 , wherein when the filter element is in the expanded configuration, the filter element has a percent open area greater than 60 percent.
15. A device of claim 1 , wherein when the filter element is in the expanded configuration, the filter element has a percent open area greater than 70 percent.
16. A device of claim 1 , wherein when the filter element is in the expanded configuration, the filter element has a percent open area greater than 80 percent.
17. A device of claim 1 , wherein the self-expanding filter mesh material has a tensile strength greater than 70,000 psi.
18. A device of claim 1 , wherein the self-expanding filter mesh material has a tensile strength greater than 100,000 psi.
19. A device of claim 1 , wherein the self-expanding filter mesh material has a tensile strength greater than 200,000 psi.
20. A device of claim 1 , wherein the self-expanding filter mesh material is made of metal.
21. A device of claim 1 , wherein the self-expanding filter mesh material is made of nitinol.
22. A device of claim 1 , wherein the self-expanding filter mesh material comprises wires braided to form diamond-shaped pores.