Assembly comprising a blood filter for temporary or definitive use and device for implanting it, corresponding filter and method of implanting such a filter

Claim 1

A blood filter assembly comprising: a filter portion including: (a) a centrally located head; (b) first legs connected at first ends thereof to the centrally located head and diverging in a first direction to form a first conical profile when unrestrained; (c) second legs connected at first ends thereof to the centrally located head and diverging in a second direction, opposite the first direction, to form a second conical profile that is inverted with respect to the first conical profile, when unrestrained, the second legs defining an internal passage therebetween when restrained, said internal passage having a minimum diameter; an implantation portion including: (d) a sleeve for removably enclosing the filter portion in a radially restrained state; (e) a maneuvering flexible rod having a distal end and at least a portion of an external diameter smaller than said minimum diameter of the internal passage defined by the second legs in the radially restrained state, said at least a portion of the flexible rod being disposed in the passage between the second legs when the second legs are in the sleeve; (f) said distal end of the flexible rod and a profile of the head of the filter portion being engaged to complete a releasable connection between the flexible rod and the filter portion for displacing the filter portion from the sleeve into a blood vessel; (g) the connection existing when the filter portion is temporarily implanted in the vessel permitting axial displacement of the filter portion in axially opposite directions within the sleeve accompanied by retention of the second legs within the sleeve, and the connection being completely released during indefinite implantation of the filter portion in said vessel when the second legs are freed from the sleeve.