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Ohio State engineers creating a more efficient insulin pump

Diabetes is a complicated condition requiring medical devices and a multitude of medications for patients. Keeping up with the treatment is often a burden unto itself.

A team at The Ohio State University Department of Electrical and Computer Engineering (ECE) is doing its part to make treatment of Type One diabetes a lot more simple. They proposed a new kind of insulin pump, a device improving upon others currently in the market. Not only is it powered wirelessly, but it is much smaller in size.

YanIn collaboration with Cornell University; the Buckeyes on the team include ECE assistant professors Liang Guo and Asimina Kiourti, Internal Medicine Assistant Professor Kathleen Dungan, along with recent Ph.D. graduate Brock DeLong and current Ph.D. student and Graduate Research Associate Bingxi Yan

“All of our work could be a significant optimization or revolution based on the current pumps,” Yan said, on behalf of the group. “The difference between commercially available pumps and our pump is the reduction on size and power consumption.”

Patients typically prefer smaller and lighter devices, he said, especially if it is implanted into the body. To accomplish this, the engineers explored radio frequency (RF) power to have it operate wirelessly.

If RF technology allows cellphones to charge wirelessly, he said, why can’t an insulin pump be powered the same way? The advancement eliminates the need for a bulky battery and creates a lifelong device.  

Since Yan’s research interests lie in electroactive polymers, also known as artificial muscles, he focused on a balloon design, or squeeze operation, in order to contain the insulin in a reservoir and release it as needed.

“The balloon is elastic and soft and could be squeezed easily. We wrapped the outer surface with artificial muscles, the polymers," Yan said. "So, when the polymers shrink in volume, it triggers a squeezing effect on the balloon and any liquid contained.”

Because of a check valve, he said, the squeezer pushes the insulin in only one measurable direction. 

Other vital components of the pump include a silicon polymer catheter tip, accommodating a porous material similar to Teflon, as well as the external wireless RF powering unit. 

DeLong and Kiourti dealt with the electrical components of the device. They designed the wireless power harvesters. These actuate the pump from the outside, and do away with the need for implanted batteries inside the patient, which frequently require replacement and are susceptible to infection.  

Kiourti said the benefits of going battery-free are numerous.

“The patient wears a smart garment that sends a wireless RF signal toward the implanted insulin pump – this signal is very much like conventional Wi-Fi or Bluetooth signals that we are all very familiar with,” she said. “In turn, the pump captures this RF signal, converts it into DC, and uses this DC signal for actuation. In this case, actuation means squeezing the pump to release insulin. For us, this is a huge step toward completely battery-less implants.”

As for Yan, he is currently working on the next manuscript for the device and plans to present the scientific results by this September.

The group is also considering adding some sensors to the pump to detect the levels of glucose and automatically determine the amount of insulin needed. The sensors are used in current pumps and help tremendously since the diabetic is not required to do calculations. 

Yan hopes to continue working on the pump post-graduation and plans on earning his Ph.D. this autumn. 

He said working on the project allows him to understand how engineering can help society in many ways. 

“This is the first time I realized the materials can be converted into some real contribution, with medical applications and cutting-edge devices for patients,” Yan said.

For more information on the pump, check out the teams most recent research article at IEEE Xplore, published on May 24, 2018.

Article by: Lydia Freudenberg, ECE Public Relations Writer