Afterloader for a throbbing heart under investigation

摘要

An examination device for a heart. An afterload device connected to the aorta provides a counterpressure by an annular space delimited between a rigid cylinder and an elastic tube inserted in the rigid cylinder. The annular space comprises a compressible medium, such as air, nitrogen gas or carbon dioxide and is connected to a reservoir providing a predetermined pressure corresponding to a diastolic pressure. The reservoir is connected to the annular space via a restriction and a back-flow valve. During diastole, the annular space is inflated by the reservoir and provides a diastolic counter pressure for providing coronary flow. During systole, the ejected fluid from the heart ventricle displaces the medium inside the annular space through the restriction to the reservoir, thereby removing energy from the fluid. The compressible medium forms a compliance. In addition, there is a preload device comprising a vertical collapsible tube forming a fluid column for preload of the atrium with a desired preload pressure without introducing air into the fluid. A pump delivers fluid to the preload device and removes fluid from the afterload device.