In middle school, Sedona Cady first learned about the nervous system—and she was hooked. But it wasn’t until her undergraduate studies that she revisited that interest, deciding to pursue neurosciences as her field of study. Then, determined to earn a doctorate degree, she set her sights on Case Western Reserve University’s Case School of Engineering, where she is now a PhD candidate in biomedical engineering with plans to graduate this fall.
With keen interest in neural engineering, Cady is part of a team studying a fully implanted device to restore the sense of touch and movement for individuals with upper extremity amputations. The device includes nerve cuffs that stimulate peripheral nerves that once innervated the skin in the amputated region, creating a sense of touch in the restored hand region.
Her work involves characterizing the sensory experiences of using the device and understanding how using the full system at home affects self-efficacy.
“The device includes intramuscular electrodes that record muscle activity, and we create algorithms to decode the user’s intended movement to move a prosthetic arm,” Cady explained. “The prostheses we use have sensors on the fingers, palm and back of the hand so that when an individual presses an object against the sensors, the user feels a sensation in a similar location.”
The success of the research project recently gained attention and funding from the Defense Advanced Research Projects Agency (DARPA), which funds defense-related projects, and the U.S. Department of Veteran Affairs. As the graduate student leading the project, Cady participated in the Pentagon’s Demo Day 2023 in October to showcase the work alongside other team members and one of their study participants.
“Our participant is an integral part of the team, and he demonstrated how he is able to use his neuroprosthetic device while also explaining its importance,” Cady said. “Individuals who have volunteered to serve our country in the armed forces may experience traumatic limb loss, and this was the importance of demonstrating the technology.”
Read on for a deeper understanding of Cady’s research and her experience at the Pentagon Demo Day.
Answers have been lightly edited for clarity and length.
1. What led you to pursue a PhD at Case Western Reserve University? What motivated you to pursue this specific area of biomedical engineering?
I studied biomedical engineering during my undergraduate [experience] at Ohio State University. I originally picked the major because I knew I liked math and science and thought biomedical engineering combined basically all of the science subjects I enjoyed. I also always enjoyed learning about psychology and the nervous system, so I decided I wanted to pursue neural engineering. I had completed a summer research program at the University of Pittsburgh studying brain computer interfaces in a monkey model, and after enjoying the experience, I decided that I wanted to continue studying neuroprosthetics or brain computer interfaces in graduate school.
I ended up choosing to study at Case Western Reserve University for my PhD because I wanted to work with Dustin Tyler on his project involving somatosensory neuroprosthetic devices. I was also excited about all of the human research in CWRU’s biomedical engineering department. My motivation to pursue this research topic stems from when I originally interviewed with Dr. Tyler. He mentioned how he was planning on running a randomized clinical trial to study his implantable technology, and I thought my interests and skills would be a good fit to work on the project.
2. How did you get involved with the Pentagon Demo Day and how did attending impact your perspective on areas of your research?
There was a wide variety of defense research featured at the Pentagon Demo Day. The booths next to us showcased neuroprosthetic devices for individuals with spinal cord injury and a group that converted waste products in defense to usable materials. Interacting with individuals working in the Pentagon who stopped by our booth was eye-opening in that we were able to hear about veterans and friends’ experiences with limb loss and other injuries while serving our country. It was also interesting learning about projects outside of biomedical research, such as hardware security and automated robotics for defense research.
3. What real-world applications or potential impacts does your research have on healthcare or other industries?
Restoring the sense of touch to upper extremity prosthesis users has previously shown to improve quality of life, self-efficacy, confidence and several other psychosocial outcomes. Commercializing our bidirectional implantable device may allow both upper and lower limb prosthesis users to experience a restored hand or foot.
4. Were there any obstacles you encountered during your research, and how did you address them?
Due to the nature of human subjects research, there have been several obstacles along the way, [such as] delays in manufacturing implanted parts, delays from COVID-19, and difficulties in finding operating rooms for our surgical implants. We make sure to be completely honest with our study participants about the timeline and expectations of the study.
Throughout these obstacles I have learned about implanted technology translation and the challenges of running a clinical trial.
5. Looking ahead, what are your goals post graduation?
After graduation, I would like to work in industry for a medical device company. I would ideally like to continue working for a company that develops neuromodulation devices, but I also think the skills I have developed as a PhD student will apply to other types of companies as well.