The embodiment consists of 2 layers. Layer 1 (16) is immobile and adherent to the basement. Layer 2 (17) reflects from layer 1 and faces the cavity. Layer 2 moves inwards (systole) and backwards (diastole) by between-layers Concertina-like elastic fibers and/or a spring (22), on-surface diagonally crossing elastic fibers (27), or sheets (29&30) of electromagnetic coils (34), that are adherent to both layers from the inside. Layer 2 moves through the electromagnetic coil causing its attraction to layer 1, when polarities are different and repulsion when polarities are similar.
