Oregon: Engineers at Oregon State University have used “additive
manufacturing” to create an improved type of glucose sensor for patients
with Type 1diabetes, part of a system that should work better, cost
less and be more comfortable for the patient. A key advance is use of electrohydrodynamic jet, or “e-jet” printing,
to make the sensor. Conceptually, e-jet printing is a little like an
inexpensive inkjet printer - but it creates much finer drop sizes and
works with biological materials such as enzymes, instead of ink.
The technology would create an “artificial pancreas” using a single
point of bodily entry, or catheter, instead of existing systems that
require four entry points, usually in a type of belt worn around the
waist.
“This technology and other work that could evolve from it should
improve a patient’s health, comfort and diabetes management,” said Greg
Herman, an OSU associate professor of chemical engineering.
These systems provide constant monitoring of blood glucose
concentrations and are matched with portable infusion pumps. They
control delivery of the hormones insulin and glucagon, and maintain safe
levels of glucose in the blood.
The findings have been reported in the ECS Journal of Solid State
Science and Technology, in work supported by the National Institutes of
Health.
Type 1 diabetes, which used to be called juvenile diabetes, can lead
to serious health complications unless glucose levels are carefully
controlled. Problems can include retinopathy, blindness, neuropathy,
kidney and cardiac disease.
Researchers say that this system may ultimately prove useful with
Type 2 diabetes as well, and that it has the capability of making other
biological measurements, beyond just blood sugar.
Diabetes is a global, rapidly increasing health problem. In 2014, the
International Diabetes Federation estimated that 387 million people
around the world had some type of diabetes, and that number is expected
to rise to 592 million within 20 years. The global economic cost last
year was estimated at $612 billion, and the agency reported that more
than three out of four people with diabetes live in low or middle-income
countries.
From an engineering perspective, the new approach is more precise,
less intrusive, uses fewer processing steps, avoids waste and costs
less.
“These are disposable devices that only last about a week and then
need to be replaced,” Herman said. “Some other approaches used to make
them might waste up to 90 percent of the materials being used, and
that’s a problem in a throw-away sensor. It’s also important to keep
costs as low as possible, and printing systems are inherently low-cost.”
Another important advance was the use of plastic substrates, which
are the same thickness as kitchen plastic wrap, so that the sensors can
be wrapped around a catheter.
“The challenges of making these sensors on such thin plastic films
were difficult to overcome, but we found that additive manufacturing
approaches simplified the process, and should lead to much lower costs,”
said John Conley, an OSU professor of electrical engineering.
A patent has been applied for on the technology by OSU and Pacific
Diabetes Technologies of Portland, Ore., which is working to
commercialize the system. It’s already being tested in animals, and
there are no apparent obstacles to its development in the health
marketplace, Herman said.
Collaborators on the research included the OSU School of Chemical,
Biological and Environmental Engineering; OSU School of Electrical
Engineering and Computer Science; Oregon Health & Science
University; and Pacific Diabetes Technologies. Other support came from
the Leona M. and Harry B. Helmsley Charitable Trust, the Oregon
Nanoscience and Microtechnologies Institute, and the Juvenile Diabetes
Research Foundation.