Blood pumping device

A blood pumping device comprising

• a first pump and a second pump, and
• a first and second pump actuators for inducing a blood flow in a body's circulatory system,
• each of said first and second pumps comprising one upper chamber having an inlet channel and one lower chamber having an outlet channel, said upper and lower chambers are separated by a movable valve plane provided with a valve;
• and said first and second pump actuators are configured to apply a force inducing a movement to said valve planes in an upward and downward direction between said upper and lower chambers in response to control signals from a control unit, such that when said valve planes moves in an upward direction, the valves provided in the valve planes are in an open position allowing a flow of blood from the upper chambers to the lower chambers, and when the valve planes moves in a downward direction the valves are in the closed position and blood is ejected from the lower chambers through the outlet channels,
• characterized in that each one of the lower chambers is provided with a bag portion at a bottom part of the lower chamber between the valve and the outlet channel, wherein an inner surface of the bag portion defines a stopping surface at a bottom of the bag portion, wherein the bottom of the bag portion has a shape that:
• makes a turn of between 110° to 150° to cause blood entering the lower chamber to hit the stopping surface and come to a sudden stop, wherein the turn causes the flow of blood along the inner surface of the bag portion to abruptly change;
• and directs blood at the stopping surface to continue flowing along the outlet channel.