BLOOD PUMP SYSTEMS AND METHODS

摘要

The present invention relates to a rotary blood pump with a double pivot contact bearing system with an operating range between about 50 mL/min and about 1500 mL/min, wherein the force on the upper bearing is less than 3N during operating speeds up to 6000 rpm. The rotary blood pump is part of a blood pump system that includes blood conduit(s), a control system with optional sensors, and a power source. Embodiments of the present invention may include elements designed to increase the length of time the rotary blood system can operate effectively in vivo, including wear resistant bearing materials, a rotor back plate for magnetic attraction of the rotor to reduce bearing pivot bearing forces and wear, a rotor size and shape and a bearing gap that combine to create a hydrodynamic bearing effect and reduce bearing pivot bearing forces and wear, improved intravascular conduits with increased resistance to thrombosis, conduit insertion site cuffs to resist infection, and conduit side ports amenable to the easy insertion of guidewire and catheter-based medical devices to treat conduits and related blood vessels to maintain blood pump system function over time. The pump system is configured to connect to the vascular system in a patient and pump blood at a desired rate. The invention also relates to a method of using a blood pump system for persistently increasing the overall diameter and lumen diameter of peripheral veins and arteries by persistently increasing the velocity of blood and the wall shear stress in a peripheral vein or artery for period of time sufficient to result in a persistent increase in the overall diameter and lumen diameter of the vessel is provided. For blood pump systems intended for use to increase the overall diameter and lumen diameter of a blood vessel, the pumping of blood is monitored and adjusted, as necessary, to maintain the desired elevated blood velocity and wall shear stress, and the desired pulsatility in the target blood vessel in order to optimize the rate and extent of the persistent increase in the overall diameter and lumen diameter of the target blood vessel. The blood pump system may also be used to reduce venous hypertension in a lower extremity and increasing the rate of healing of lower extremity venous ulcers in patients is provided. For blood pump systems intended for use to treat venous hypertension of an extremity, the pumping of blood is monitored and adjusted, as necessary, to maintain the desired venous blood pressure in the treated extremity.