Triple lumen catheter

A triple lumen catheter for use in treatment of humans by inserting the catheter into a blood vessel over a Seldinger guide wire having a round cross-section, and using the catheter to extract blood at a selected location in the blood vessel and to return treated blood downstream of the location after treatment, the catheter comprising:

• an elongate body extending about a longitudinal axis from a proximal end to a distal end;
• a tip at the distal end of the body;
• the body having an outer wall and an integral internal septum combining with the outer wall to define a pair of similar C-shaped lumens extending longitudinally;
• the outer wall of the body defining at least one intake aperture and at least one return aperture, the intake aperture being spaced longitudinally from the tip and from the return aperture, and the return aperture being nearer the tip than is the intake aperture sufficient to limit the likelihood that treated blood leaving the return aperture will be inspired into the intake aperture;
• one of the C-shaped lumens terminating at the intake aperture to form an intake lumen, and the other of the C-shaped lumens terminating at the return aperture to form a return lumen;
• the septum defining a third lumen smaller than the C-shaped lumens and having a round cross-section proportioned to slidably receive the guide wire during insertion and to provide a path for medicament after insertion, the third lumen terminating at the longitudinal extremity of the tip so that the third lumen is as long as the catheter;
• a connector attached to said proximal end of the body;
• a pair of tubes attached to the connector and coupled by the connector to the respective C-shaped lumens to carry blood from the intake lumen and to return treated blood to the return lumen;
• a third smaller tube attached to the connector and coupled by the connector to the third lumen to receive the guide wire during insertion and to provide access for intravenous medicament through the third lumen during use;
• and
• the body and the tip combining to present a smooth transition from the cross-section of the body to a smaller cross-section at the distal end.