Fig. 1

The cardiac cycle (a) together with a heart model (b): (1)—valve balloon; (2)—ventricular balloon; (3)—cylindrical orifice inside a mitral valve location; (4)—aorta; (5)—left ventricle; (6)—left atrium; (7)—narrowing; (8)—aortic valve location; (9)—pneumatic line; (10)—pulmonary vein.