Ki Chon, Krenicki Chair professor of biomedical engineering, in collaboration with Hugo Posada-Quintero, assistant professor of biomedical engineering, and his graduate student are working on a new application of their novel electrodermal activity (EDA) sensor technology to predict seizures in underwater environments.
Chon and Posada-Quintero have received two grants totaling $1 million from the Office of Naval Research to investigate how these sensors could be used to predict seizures – a significant health threat for naval divers.
Navy SEAL divers and submariners breathe hyperbaric oxygen (HBO2), pressurized pure oxygen, during underseas operations. Prolonged exposure to HBO2 can lead to oxygen toxicity which can cause seizures and other complications.
Chon and his team have long had an interest in using quantitative methods to measure the activity of the sympathetic nervous system, which registers pain and other health events, like seizures.
When Chon was a postdoctoral researcher at the Massachusetts Institute of Technology, existing methods could not separate the sympathetic nervous system (which controls the fight-or-flight response) from the parasympathetic nervous system (which controls everyday processes like digestion and bringing the body back to a resting state).
“These work in parallel,” Chon says. “But you need to separate out sympathetic and parasympathetic because pain, for example, invokes the sympathetic system. So, you use that to better quantify the amount of pain you’re feeling.”
Given this challenge, researchers had begun to investigate the potential of EDA sensors, which use signals from the skin to quantify activity in the sympathetic nervous system.
“It makes sense because human skin is only innervated by the sympathetic nerves,” Chon says.
“That’s the beauty of it. You can measure these things anywhere in the skin with sweat pores and it’s basically measuring your sympathetic response.”
The EDA device consists of a small circuit and a series of electrodes that can measure sympathetic system activity in real time.
Chon and his team developed an algorithm that could better characterize this response using a technique of time-varying spectral analysis of raw EDA (TVSymp). TVSymp produced more consistent and accurate responses compared to the traditional way of interpreting EDA data.
This technology has been patented through UConn Technology Commercialization Services. Chon holds two patents with the US Patent and Trademark Office and has filed two other provisional patents related to this technology.
Previously, Chon worked with I-Ping Chen, associate professor of endodontics at UConn Health, to miniaturize his sensors to gauge patient pain during root canals.
The sensors not only provide surgeons with a more accurate measurement of patient pain than patients self-reporting, but they also help overcome communication challenges for young children, patients with disabilities, and patients with language barriers.
Chon’s current project follows his finding that, using his algorithm, the sensors could also predict seizures. In a study using rats exposed to HBO2, the sensors detected a seizure on average two minutes before either the EEG measurement or an expert viewing a video of the rat.
Those few minutes can make a huge difference for divers and submariners, as they could allow someone to be warned and return safely to the surface before the seizure starts.
“One minute is certainly a significant time in advance to warn them,” Chon says. “That’s something we’re very excited about, and the Navy’s very excited about.”
Other potential applications for this widely adaptable platform technology include socks to detect neuropathy (damage to peripheral nerves) in patients with diabetes or cancer-induced neuropathy. This application could be linked to patients’ smartphones and provide an early warning, allowing them to seek treatment before they potentially lose their foot.
“There are a lot of applications because the sympathetic, as well as parasympathetic, nervous systems are implicated in many types of diseases,” Chon says. “There’s a host of problems you could go after.”