AMLCI Partners with Podiatry College to Design New Device
Foot ulcers are one of the most prevalent and dangerous problems facing diabetic patients, but new technology developed at Kent State University may soon help doctors better understand and treat them.
The device, called a “dynamic plantar shear sensor,” represents a breakthrough for physicians to understand how plantar ulcers form.
It has long been believed that plantar ulcers in diabetic patients form at areas of highest plantar pressures,” said Dr. Vincent Hetherington, Professor of Podiatric Medicine. “However, the correlation of plantar pressure and ulcer formation is unclear. Many researchers have long believed there was a missing link.”
Recent studies suggest that the missing link could involve shear forces that may play a significant role in ulcer development.
Unlike direct forces, created when the foot comes straight down, shear force pushes one part of the tissue in one direction and another part in the opposite direction.
The device was developed and built by KSU alumnus Dr. Misha Pevnyi and Tianyi Guo, a graduate student in KSU’s Chemical Physics Interdisciplinary Program in the Advanced Materials and Liquid Crystal Institute (AMLCI). The project, funded by a grant from the Ohio College of Podiatric Medicine, was overseen by Dr. Peter Palffy-Muhoray and Dr. Hiroshi Yokoyama — both in the AMLCI — in addition to Dr. Hetherington.
“Shear forces are hard to measure,” Dr. Palffy-Muhoray said. “It’s relatively easy to measure the pressure under foot, and devices already exist to do that, but the question was how to effectively measure shear?”
The answer, Pevnyi and Guo found, was to transduce shear stresses to more easily measurable local pressures.
Little bigger than a large computer keyboard, a platform was made mostly of specially shaped pressure plates, 3D printed in Dr. Palffy-Muhoray’s lab, with a pivot plate on top and electrodes and microprocessor-based electronics for data-collection beneath. Data are automatically uploaded to a web server for instant access and monitoring via smart phone.
Guo worked on the 3D printing and layout while Pevnyi did the electrical and software development. AMLCI engineer Merrill Groom contributed to the IC chip design and assembly.
“The new device can measure both plantar pressure and shear forces simultaneously,” Dr. Hetherington said. “To the best of our knowledge, at present there is no comparable device commercially available.”
He said the next steps include improvements of the prototype and clinical testing, followed by use of the technology as a medical analysis tool. Future goals include developing a device for in-shoe application.
The KSU Patent Board has recently approved the device for federal patent application, and funding to continue development is currently being sought.
Palffy-Muhoray said the project is also unique because of its altruistic nature.
“The device is the first of its kind, and there’s this really nice aspect of two young people putting tremendous effort into it, not for money or even the prospect of money, but essentially just to help sick people,” he said. “Misha, who is now developing software for a financial company, drove here on weekends from Chicago,” Palffy-Muhoray said. “And Tianyi took time off from her thesis to work on the project.”