An aspiration catheter is provided in which vacuum may be accumulated within the catheter and released suddenly within a distal region of the catheter to induce ingestion of intravascular matter into the catheter through an open distal port while avoiding large losses of suction common with catheters...http://www.google.com.au/patents/US7942852?utm_source=gb-gplus-sharePatent US7942852 - Aspiration catheter having an internal vacuum accumulator
