| 摘要 |
An improved embolic filter frame having looped support struts. The frame configuration provides enhanced longitudinal compliance, improved sealing against a vessel wall, low profile delivery, and a short deployed length. The looped support struts have a high degree of "radial" stiffness with a low degree of "longitudinal" stiffness. In the deployed state, the frame exerts a relatively high stress onto a vessel wall to maintain an effective seal, yet remains compliant in the longitudinal direction. Minor displacements of the support wire or catheter are therefore not translated to the filter. The looped support struts elongate when tensioned and assume a compressed and essentially linear form. While constrained in this linear state by a delivery catheter, the support struts exert minimal stress onto the delivery system. The overall delivery profile and stiffness are therefore reduced. When the delivery catheter constraint is removed during deployment, the struts "snap open" and assume a looped configuration which exert a high degree of force onto the vessel wall, creating an enhanced filter to vessel wall seal. In addition, the looped struts and the central collar connecting the support struts to the support wire, are positioned essentially within the plane of the filter opening. The overall deployed length of the embolic filter is therefore reduced. |
