REMOVABLE MEDICAL FILTER
A medical filter intended for placement inside a tubular body passage such as a blood vessel of a patient, the medical filter having an end member at one end of the longitudinal axis of the filter. The end member supports a retrieval element and a plurality of struts defining a first filter cone proximate to the end member and a second filter cone distal from the end member.
1 . An elongated, radially expandable and compressible medical filter with a longitudinal axis, intended for placement inside a tubular body passage such as a blood vessel of a patient, the medical filter comprising in expanded form:
(A) an end member at one end of the longitudinal axis of the filter with a retrieval element;
(B) a plurality of struts with first segments extending generally radially outwardly and axially from said end member, each of said struts having a middle segment extending generally in a cylindrical plane about said longitudinal axis and an end segment extending generally radially inwardly and axially with free ends spaced from said longitudinal axis.
2 . The medical filter of claim 1 wherein said middle segments of said struts extend generally parallel to each other and to the longitudinal axis of the filter.
3 . The medical filter of claim 1 wherein said middle segments of said struts are in the plane of a cylinder and extend in a spiral manner.
4 . The medial filter of claim 3 wherein said first segments extend in a spiral manner.
5 . The medical filter of claim 4 wherein said end segments extend in a spiral manner.
6 . The medical filter of claim 2 wherein said end segments extend in a spiral manner.
7 . The medical filter of claim 1 wherein said retrieval element is a hook.
8 . The medical filter of claim 1 , wherein said filter is comprised of Nitinol.
9 . The medical filter of claim 1 wherein said filter is comprised of stainless steel.
10 . The medical filter of claim 1 wherein said struts are comprised of wire.
11 . The medical filter of claim 1 wherein said struts are cut from tubing.
12 . A radially expandable and compressible, elongated medical filter having a longitudinal axis, said filter intended for placement inside a tubular body passage of a patient and comprising in expanded form:
(A) an end member at one end of the longitudinal axis of the filter with a retrieval element;
(B) a plurality of struts with first segments extending generally radially outwardly and axially from said end member to define a cone shaped first filter basket, each of said struts having a middle segment extending generally in a cylindrical surface about said longitudinal axis and an end segment extending generally radially inwardly and axially with free ends spaced from said longitudinal axis to define a cone shaped second filter basket.
13 . The medical filter of claim 12 wherein said middle segments of said struts extend generally parallel to each other and to the longitudinal axis of the filter.
14 . The medical filter of claim 12 wherein said middle segments of said struts are in the surface of a cylinder and extend in a spiral manner.
15 . The medical filter of claim 12 wherein said first segments extend in a spiral manner.
16 . The medical filter of claim 12 wherein said end segments extend in a spiral manner.
17 . The medical filter of claim 15 wherein said end segments extend in a spiral manner.
18 . The medical filter of claim 13 wherein said filter is comprised of Nitinol.
19 . The medical filter of claim 13 wherein said filter is comprised of stainless steel.
20 . The medical filter of claim 1 wherein said legs are comprised of wire.
21 . The medical filter of claim 1 wherein said legs are cut from tubing.