an isolated heart or heart - lung preparation in which essentially normal pumping activity of all four chambers of the heart is preserved , allowing for the use of the preparation in conjunction with investigations of electrode leads , catheters , ablation methods , cardiac implants and other medical devices intended to be used in or on a beating heart . the system can be designed to be used within a magnetic resonance imaging unit or a x - ray computed tomography scanner . the preparation may also be employed to investigate heart and lung functions , in the presence or absence of such medical devices . in order to allow comparative imaging visualizations of either or simultaneously the heart and / or lung structures and devices located within the chambers of the heart or vessels or bronchi within the lungs , a clear perfusate such as a modified krebs buffer solution with oxygenation is circulated through all four chambers of the heart and thus the coronary and / or pulmonary vasculatures . a ventilator with intubation tube can be used to inflate / deflate the lungs and / or provide oxygen to the isolated organs . the preparation and recordings of the preparation may be used in conjunction with the design , development and evaluation of devices for use in or on the heart and / or lungs , as well as for use as an investigational and teaching aid to assist physicians and students in understanding the operation of the cardiopulmonary system .