BME Students Built $40 Insulin Pump, Handsfree Computer Mouse

Biomedical engineering students in BME 264, the biomedical instrumentation course taught by Associate Professor Patrick Wolf, capped off another semester with poster presentations of their inventions on Dec. 12.

Kelly Fitzgerald and Patrick Parish presented a $40 insulin pump. By stripping the pump down to its bare essentials, such a device could offer those with diabetes who are unable to afford a $6,000 commercially available pump the advantage of improved insulin control, according to Fitzgerald.

“It doesn’t have a lot of the extra features, but we were able to cut the price down considerably,” she said.

Another project on display from Wolf’s course included a bioimpedance analyzer built by students John Kang and Blake Byers. Such analyzers measure changes in the electroconductivity of tissue samples, which can relay information about the function of the heart or other organs. Their goal was to create a device that was much more portable and cheaper than the desktop versions now available.

“Actual analyzers cost $10,000 and are used to look at material characteristics of tissue samples,” Byers said. “Our device costs $240, but it’s not as accurate.”

Byers said he would ultimately like to see a bioimpedance analyzer that could be used to track the response of cancerous tumors to therapy, noting that changes in properties can signal the death of cells. However, the analyzers’ sensitivity to small changes in the water content of body tissues would make such a use a challenge, he said, and may ultimately limit their utility to more controlled laboratory conditions.

Mike Zimmerman and John Galanek presented their “Tilt and Nod” hands-free computer mouse. The device, incorporated into a Pratt School baseball cap, allows a user to navigate the computer with the use of head motions: nods move the cursor up and down and tilts of the head move the cursor from side to side.

“There’s a learning curve, but you get used to it,” Zimmerman said of the mouse, noting that he and Galanek had successfully used the device to play the classic computer game MineSweeper.

The pair got the initial idea for the mouse from a project designed by others previously in the course. That device was meant to allow a user to control the cursor with hand motions.

“We thought we would adapt the idea for head motion,” Zimmerman said. “If you can use your hand, you can probably use a regular mouse.”

The team said that their tilt and nod mouse could be useful for those lacking the use of their hands due to disability. It might also be useful in situations in which a person’s hands must be occupied with other tasks, they added, for example, for surgeons in the operating room.

A Menu of Options

BME students now have their choice of five “capstone” courses: BME 260: Devices for People with Disabilities, BME 264: Biomedical Instrumentation, BME 261/262 Design for the Developing World, BME 265: Biophotonics Instrumentation and BME 227: Design in Biotechnology, said Associate Professor of the Practice Aura Gimm, who teaches the biotech design course.

Gimm’s course, along with BME 260 and 261/262, have a “client-driven focus,” she said, as students select among projects identified by the medical school and other departments at Duke or other local and international groups. In others, students have the opportunity to invent their own project ideas.

The biophotonics course gives students a background in the theory and laboratory practice in optics, and in the design of optical instruments for biomedical applications, according the instructor for that course, Professor Joseph Izatt. After getting up to speed on optics, students this semester had the option of building several devices, including a pachymeter, which measures the thickness of the eye’s cornea, and a body fat analyzer. Students could also invent an instrument of their own.

In Professor of the Practice Robert Malkin’s design course, BME 261/262, students gain design experience by developing a device that is in demand at clinics and hospitals of the developing world. The project ideas are developed by student participants in the Engineering World Health Summer Institute, who spend time repairing equipment in hospitals or clinics of Africa and Central America each summer.

Students in Assistant Research Professor Larry Bohs’ course, BME 260, build customized equipment for individuals in the local community who have a need that is unmet by commercially available products.

All the courses build on content that students are exposed to in earlier courses, Gimm said. For example, her biotech design course relies primarily on subject matter covered in classes including Biomaterials, Biomechanics, Biotransport and Cellular and Molecular Modeling, she said.

While students can choose to take the course or courses that best suit their experience and interests, Gimm said, the hands-on classes each provide exposure to core topics: basic design principles, ethics and professionalism.