A catheter device regulates fluid flow within a circulatory vessel. Included is an elongated catheter body configured to access one of a circulatory vessel or a heart chamber. The catheter body includes a proximal end, a distal end, and a first lumen including an open proximal end and a distal end with...http://www.google.com/patents/US6059757?utm_source=gb-gplus-sharePatent US6059757 - Single lumen catheter with controlled antegrade and retrograde flow
