<p>The condensation chamber (1) has a volume chamber (2) having connection unit (3) for connecting the volume chamber to natural cardiovascular system. The volume change of volume chamber is effected by a pressure change in the cardiovascular system. An adapting unit is provided with a frame (4) that is connected with spring (5). The frame and spring are arranged outside the volume chamber. The frame is provided with two end portions (6) connecting the supporting rods (7). The spring is extended between the rods.</p>