A team of University of Arizona (UArizona) researchers has developed an ultra-thin wireless device that grows to the surface of bone and could someday help physicians monitor bone health and healing over long periods. The devices are called osseosurface electronics.
“With this interface, you basically have a computer on the bone,” said Philipp Gutruf, PhD, an assistant professor of biomedical engineering and Craig M. Berge faculty fellow in the College of Engineering at UArizona. “This technology platform allows us to create investigative tools for scientists to discover how the musculoskeletal system works and to use the information gathered to benefit recovery and therapy.”
The device is about as thick as a sheet of paper, which means it can conform to the curvature of the bone, forming a tight interface. It does not need a battery to operate; rather, it uses a power casting and communication method called near-field communication, which is also used in smartphones for contactless pay.
The outer layers of bones shed and renew just like the outer layers of skin. So, if a traditional adhesive was used to attach something to the bone, it would fall off after just a few months. To address this challenge, the team developed an adhesive that contains calcium particles with an atomic structure similar to bone cells, which is used to secure osseosurface electronics to the bone.
“The bone basically thinks the device is part of it, and grows to the sensor itself,” Gutruf said. “This allows it to form a permanent bond to the bone and take measurements over long periods of time.”
For instance, a doctor could attach the device to a broken or fractured bone to monitor the healing process. This could be particularly helpful in patients with conditions such as osteoporosis, since they frequently suffer refractures. Knowing how quickly and how well the bone is healing could also inform clinical treatment decisions, such as when to remove temporary hardware like plates, rods, or screws.