Student Uses Chaos Theory to Create a New Medical Tool
What started as a love of physics and an interest in biology has turned into a promising new method to potentially identify disease. Allison Hilbun, a doctoral student in quantitative bioscience in the Department of Biomedical Science, turned her focus to health when she wanted to find a way to use her strong quantitative skills to help people. She found a mentor in Dr. Istvan Karsai in the Biology department at ETSU. Together, they have developed an ambitious project to further the understanding of patient balance, movement, and disease.
Hilbun and Karsai are among a few research groups looking at the link between balancing/involuntary movements and health status. A project in Japan at Kyoto University has begun to demonstrate a strong correlation between a patients standing balance and brain health, specifically the thickening and bleeding of small blood vessels in the brain. Most interestingly, often the patients tested were otherwise asymptomatic. This means that the longer a patient could steadily stand on one leg, the lower their risk for several circulatory and inflammatory diseases.1
Similarly, work in Switzerland concluded that spontaneous hand activity, like many other spontaneous movements in the body is not random but a fractal pattern. Researchers were further able to identify changes in motor patterns in patients hands that were correlated with a diagnosis of major depression. This is thought to be the case because depression involves a denigration of sleep cycles and internal clock mechanisms that are controlled by the same part of the brain that deals with balance and fine motor skills.2
Building on this body of research, Hilbun and Karsai used a force sensor that a patient could stand on, similar in size and shape to a bathroom scale. When the patient stood on the platform, they were able to detect the tiny chaotic micro-sways that all of us make when we stand. When they compared this with patient age, they found something interesting.
"We have found that young people have complex feedback mechanisms controlling balancing and that with age, these feedback mechanisms are replaced with more persistent feed forward loops. In addition, giving patients a sensory task to complete while balancing further decreases the strength of the feedback loops" said Hilbun.
This indicates that as we grow older, the way we balance ourselves changes in a predictable way. Our bodies become less able to adapt and instead fall into a less robust method of determining how to balance each time we stand. This can be further upset when we encounter any sort of distraction. Further research is underway to determine if patients with specific diseases demonstrate specific sway patterns when they stand and balance on the force sensor. It is hypothesized that the results will be similar to patients hand activity as measured in the Swiss study.
This work offers an exciting opportunity to develop a new diagnostic tool that could easily be placed in doctors offices and used during ordinary vital sign collection. Eventually, we may even be able to detect diseases before they show symptoms by asking patients to stand on a scale with a force sensor built in.
1. Tabara, Y., Okada, Y., Ohara, M., Uetani, E., Kido, T., Ochi, N., ... & Kohara, K. (2015). Association of Postural Instability With Asymptomatic Cerebrovascular Damage and Cognitive Decline The Japan Shimanami Health Promoting Program Study. Stroke, 46(1), 16-22.2. Aybek, S., Ionescu, A., Berney, A., Chocron, O., Aminian, K., & Vingerhoets, F. J. G. (2012). Fractal temporal organisation of motricity is altered in major depression. Psychiatry research, 200(2), 288-293.