Patent ID: 8420380

Claim:
A system for preserving a lung ex vivo comprising: a perfusion fluid circuit for circulating a perfusion fluid through the lung, the fluid entering the lung through a pulmonary artery interface and leaving the lung through a left atrial interface; a ventilation circuit for ventilating the lung through a tracheal interface, the ventilation circuit adapted to flow a captive volume of a ventilation gas back and forth between the lung and a variable volume chamber; a trickle valve in fluid communication with the ventilation circuit for introducing into the captive volume an additional volume of the ventilation gas; and a relief valve in fluid communication with the ventilation circuit for venting excess ventilation gas from the captive volume and for maintaining a minimum gas pressure of the captive volume; and wherein a gas exchange in the lung between a component of the ventilation gas and the perfusion fluid causes the corresponding gas component in the perfusion fluid to reach an equilibrium value.