Researchers at Case Western Reserve University have built a small-scale, microfabricated artificial lung that uses new mathematical modeling and a bio-inspired design to achieve oxygen exchange efficiencies much larger than current devices, thereby enabling air to be utilized as the ventilating gas.
artificial lung built by Cleveland researchers has reached efficiencies
akin to the genuine organ, using air – not pure oxygen as current
man-made lungs require — for the source of the essential element.
in humans is still years away, but for the 200 million lung disease
sufferers worldwide, the device is a major step toward creating an
easily portable and implantable artificial lung, said Joe Potkay, a
research assistant professor in electrical engineering and computer
science at Case Western Reserve University. Potkay is the lead author of
the paper describing the device and research, in the journal Lab on a
scientists 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.
on current device performance, we estimate that a unit that could be
used in humans would be about 6 inches by 6 inches by 4 inches tall, or
about the volume of the human lung. In addition, the device could be
driven by the heart and would not require a mechanical pump,” Potkay
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.
The Cleveland researchers focused first on improving efficiency and portability.
who specializes in micro- and nano-technology, worked with Brian
Cmolik, MD, an assistant clinical professor at Case Western Reserve
School of Medicine and researcher at the Advanced Platform Technology
Center and the Cardiothoracic Surgery department at the Louis Stokes
Cleveland VA Medical Center. Michael Magnetta and Abigail Vinson,
biomedical engineers and third-year students at Case Western Reserve
University School of Medicine, joined the team and helped develop the
prototype during the past two years.
researchers first 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.
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.
team is now collaborating with researchers from Case Western Reserve’s
departments of biomedical engineering and chemical engineering to
develop a coating to prevent clogging in the narrow artificial
capillaries and on construction techniques needed to build a durable
artificial lung large enough to test in rodent models of lung disease.
Within a decade, the group expects to have human-scale artificial lungs in use in clinical trials.
envision patients would tap into the devices while allowing their own
diseased lungs to heal, or maybe implant one as a bridge while awaiting a
lung transplant – a wait that lasts, on average, more than a year.
Bio-inspired, efficient, artificial lung employing air as the ventilating gas
SOURCE: Case Western Reserve University