At the University of Pittsburgh, researchers headed by William Federspiel, have been developing an artificial lung to overcome the limitations of conventional extracorporeal membrane oxygenation, which fails to sustain life in too many patients. In this month’s issue of The Journal of Heart and Lung Transplantation, the researchers document the creation and testing of the new Paracorporeal Ambulatory Assist Lung (PAAL), a prototype of a device that may lead to a wearable lung for patients waiting for or recovering from a lung transplant.
“This project will develop a compact respiratory assist device called the Paracorporeal Ambulatory Assist Lung—known as PAAL—to replace the old techniques,” said Federspiel. “This is a wearable, fully integrated blood pump and lung designed to provide longer-term respiratory support up to one to three months while maintaining excellent blood compatibility.”
The researchers just received a $3.4 million grant from the NIH to continue the development of the artificial lung with the hope of realizing a clinically validated device.
Here are some details about the new device according to the study abstract:
The PAAL features a 1.75 inch diameter cylindrical HFM bundle of stacked sheets, with a surface area of 0.65 m2integrated with a centrifugal pump. The PAAL was tested on the bench for hydrodynamic performance, gas exchange and hemolysis. The PAAL was then tested in 40-60 kg adult sheep (n=4) for 6h. The animals were cannulated with an Avalon Elite 27 Fr. DLC inserted through the right external jugular into the SVC, RA and IVC.
The PAAL pumped over 250 mmHg at 3.5 L/min at a rotation speed of 2100 RPM. Oxygenation performance met the target of 180 ml/min at 3.5 L/min of blood flow in vitro, resulting in a gas exchange efficiency of 278 ml/min/m2. The normalized index of hemolysis (NIH) for the PAAL and cannula was 0.054 g/100L (n=2) at 3.5 L/min, as compared to 0.020 g/100L (n=2) for control (DLC cannula and a Centrimag pump). Plasma-free hemoglobin (pfHb) was below 20 mg/dL for all animals. Blood left the device 100% oxygenated in vivo and oxygenation reached 181 ml/min at 3.8 L/min.
Related study in The Journal of Heart and Lung Transplantation: In Vitro and In Vivo Evaluation of a Novel Integrated Wearable Artificial Lung…
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Top image courtesy of Dr. William Federspiel.