Inlet valves for a cardiac assist device and related technology

A cardiac assist device, comprising:

• a balloon configured to move between a first state and a second state, the balloon being more inflated in the second state than in the first state;
• a shell at least partially containing the balloon, wherein the shell includes struts arranged in a mesh pattern that defines interstices;
• an aperture at a given one of the interstices, wherein the shell includes a coaptation area at a perimeter portion of the aperture, and wherein moving the balloon from the second state toward the first state tends to move fluid into the shell via the aperture;
• and
• a flap carried by the shell, wherein the flap is configured to contact the shell at the coaptation area to reduce movement of fluid out of the shell via the aperture while the balloon moves from the first state toward the second state, and to move away from the shell at the coaptation area to allow movement of fluid into the shell via the aperture while the balloon moves from the second state toward the first state.

A method of providing cardiac assist, comprising:

• intravascularly advancing a cardiac assist device toward a heart of a patient while the cardiac assist device is in a low-profile delivery state;
• locating the cardiac assist device within a cardiovascular lumen of the patient;
• moving the cardiac assist device from the delivery state to an expanded treatment state after locating the cardiac assist device within the cardiovascular lumen;
• cycling a balloon of the cardiac assist device between a first state and a second state, the balloon being more inflated in the second state than in the first state, wherein the balloon is at least partially disposed within a shell of the cardiac assist device and wherein the shell includes struts arranged in a mesh pattern that defines interstices,
• wherein cycling the balloon includes:
• moving the balloon from the second state toward the first state such that blood moves into the shell via an aperture of the cardiac assist device, the aperture being at a given one of the interstices, and
• moving the balloon from the first state toward the second state such that a flap carried by the shell contacts a coaptation area at a perimeter portion of the aperture thereby reducing movement of blood out of the shell via the aperture.

An intravascular blood pump comprising:

• a chamber having at least one inlet and an outlet;
• a volume displacement member within the chamber configured to move cyclically between a first state and a second state, wherein blood flows into the chamber through the inlet as the volume displacement member transitions from the second state to the first state and blood exits the chamber through the outlet as the volume displacement member transitions from the first state to the second state;
• and
• one or more one-way valves, each one-way valve being associated with at least one inlet, wherein each one-way valve is configured to open and close at a frequency of at least 300 times per minute.