This invention is a modular blood filter device (10) and delivery system, comprising an arterial cannula (20) with a modular filter device (10). The arterial cannula (20) includes a distal end (24) adapted to enter an artery, and a side port (32) for receiving a modular filter cartridge (42). The modular filter cartridge (42) includes a tubular cartridge (42), and a shaft (62) having a handle (68) on one end and an expandable filter device (60) on the other end. The expandable filter device (60) includes filter mesh (80) and an expansion frame (72) capable of assuming enlarged and contracted conditions. The shaft (62) is inserted into the cartridge, thereby containing the expandable filter device (60) therein. The cartridge (42) may be then removably received by the side port (32) on the cannula. The cannula (20) may be introduced into a blood vessel, and the expandable filter device (60) may be deployed through the cannula (20) into the vessel. The expansion frame (72) may be expanded to the enlarged condition to capture embolic material in the mesh (80), may be collapsed to the contracted condition, and may be removed from the vessel. The modular filter cartridge (42) may be removed from the cannula (20), and a new modular filter cartridge (42) may then be received therein.