Objectives: Currently available therapies for acute and chronic lung diseases have not been effective and have various problems associated with the technologies used. We present a novel active mixing pump-lung with the goal of providing total respiratory support to ambulatory patients.
Methods: The pump-lung is based on the concept of active mixing oxygenation within a constrained vortex. The rotation of hollow-fiber membranes disrupts the concentration boundary layer, increasing gas exchange efficiency, and simultaneously pumps the blood. Consequently, the amount of membranes required to achieve gas transfer sufficient for total respiratory support is considerably small. A series of studies, including computational design, experimental bench testing, and in vivo animal experiments, have been performed to implement this concept into a viable artificial pump-lung device.
Results: A series of pump-lung prototypes with a membrane surface area of 0.17 to 0.5 m2 were designed and characterized in vitro with bovine blood, demonstrating extremely high gas exchange efficiency. The prototype with a gas exchange surface area of 0.5 m2 was evaluated in calves. The device provided oxygen transfer of approximately 115 mL/min for respiratory support of an animal for up to 5 days.
Conclusions: Progress to date suggests a high likelihood of success for an extracorporeal shorter-term lung that can be switched in and out like dialysis devices. Our device is unique in that it incorporates an integrated pumping and active mixing principle for excellent gas transfer and eliminates the need of the native right ventricle's ability to power blood through the artificial and natural lungs.