Abstract: A removable vascular filter system for blocking micro- and macro-emboli while allowing the continued perfusion of blood comprises a filter membrane positioned on a guidewire, wherein a free end of the membrane sits tightly against the guidewire when the filter membrane is in a collapsed state and wherein the filter has a means for deploying the filter membrane to assume a position substantially normal to the longitudinal axis of the guidewire. The filter membrane is comprised of a fine mesh material which has a pore size capable of blocking emboli while allowing continued blood flow, a preferred embodiment of which comprises regularly spaced, laser-formed holes, and in which the membrane has a scalloped proximal profile.