A blood pumping device (1) comprising at least a first pump (2) and a second pump (3), and a first and second pump actuating means for inducing a blood flow in a bodys circulatory system is disclosed. Each pump (2, 3) comprises one upper chamber (9) having an inlet channel (10) and one lower chamber (12) having an outlet channel (13). The upper and lower chambers (9, 12) are separated by a movable valve plane (7) provided with a valve (14). The pump actuating means are configured to apply a movement to said valve plane (7) in an upward and downward direction between said upper and lower chambers (9, 12) in response to control signals from a control unit, such that when said valve plane (7) moves in an upward direction, the valve (14) provided in the valve plane (7) is in an open position allowing a flow of blood from the upper chamber (9) to the lower chamber (12), and when the valve plane (7) moves in a downward direction the valve (14) is in the closed position and blood is ejected from the lower chamber (12) through the outlet channel (13). The bottom part of the lower chamber (12) is provided with a bag-like portion (20)
