Intra-aortic balloon pump display. Heart and blood circulation vital signs displayed on an intra- aortic balloon pump (IABP) machine. This machine reduces the strain on a pumping heart by operating a balloon pump that has been placed in the patient's aorta (main body artery). There, it reacts to the pumping of the heart. Just before a contraction of the heart, the balloon deflates and so reduces the pressure in the aorta that the heart has to pump against. The balloon inflates after the heart pumps oxygen-rich blood into the aorta. This inflation returns oxygen-rich blood towards the heart. This device is used (as here) during, before and after heart surgery.