Researchers at Case Western Reserve University in Cleveland have designed an artificial lung that uses air instead of pure oxygen as the ventilating gas, as is the case with current man-made lungs, which require heavy tanks of oxygen.
It might be still years away to be used in humans, but the device is a major step toward creating an easily portable and implantable artificial lung, said lead reearcher Joe Potkay, a research assistant professor in electrical engineering and computer science at Case Western Reserve University.
The device could come in at just 6x6x4 inches, which is roughly the volume of the real human lung, meaning it could conceivably pave the way for implantable artificial lungs.
Potkay and his co-authors built the prototype device by following the natural lung”s design and tiny dimensions. The artificial lung is filled with breathable silicone rubber versions of blood vessels that branch down to a diameter less than one-fourth the diameter of human hair.
Current artificial lung systems require heavy tanks of oxygen, limiting their portability. Due to their inefficient oxygen exchange, they can be used only on patients at rest, and not while active. And, the lifetime of the system is measured in days.
Potkay estimates that based on current performance the unit could be powered by the heart instead of a mechanical pump.
The Cleveland researchers focused first on improving efficiency and portability.
They built a mould with miniature features and then layered on a liquid silicone rubber that solidified into artificial capillaries and alveoli, and separated the air and blood channels with a gas diffusion membrane.
By making the parts on the same scale as the natural lung, the team was able to create a very large surface-area-to-volume ratio and shrink the distances for gas diffusion compared to the current state of the art.
Tests using pig blood show oxygen exchange efficiency is three to five times better, which enables them to use plain air instead of pure oxygen as the ventilating gas.
The team anticipates testing human artificial lungs in clinical trials within a decade.
The device and research are described in the journal Lab on a Chip.