Positive flow generator for indwelling medical fluid systems

摘要

A positive pressure generator is provided proximal the valve or septum of a vascular catheter for inducing sufficient positive pressure in the lumen or fluid path of the catheter so that a sufficient portion of the fluid at the tip of the catheter is forced into the blood vessel after the cannula or needle has been removed from the hub so that any blood in the tip is displaced back into the vessel or is sufficiently diluted such that clotting within the lumen adjacent the tip is substantially mitigated. The positive pressure generator is preferably comprised of a flexible tube or cavity which has a variable internal volume and which is configured to have a first stable configuration with a first internal fluid volume and a second stable configuration with a smaller internal fluid volume.