Wearable sensors developed to detect brain disorders through eye movement

An engineering team from the University of Houston has developed wearable sensors to examine eye movements to assess brain disorders or damage to the brain. Many brain diseases and problems manifest as eye symptoms, often before other symptoms appear.

You see, eyes are not just a window to the soul, as poets claim. These incredibly valuable organs are also an extension of the brain and can provide early warning signs of brain-related conditions and information about their cause. Examining the eyes can also help monitor the progression and symptoms of physical and mental shocks to the brain.

Researchers say current eye-tracking systems are flawed and do not provide sufficient amounts of data. In addition, they are bulky, with multiple electrodes on the face and neck, expensive, and have weak output.

And in an instant…improvement.

The new method, developed in the UH lab of Jae-Hyun Ryou, associate professor of mechanical engineering, with help from Nam-In Kim, postdoctoral researcher, is non-invasive, comfortably portable and safe, allowing for simple and continuous measurements and monitoring of eyeball movements in combination with a hand-held display and computing device.

The new sensors are sleek and flexible, made of a very thin, crystal-like film that generates electricity when it bends or moves. That’s a phenomenon called the piezoelectricity effect, and it allows certain materials to generate an electrical charge in response to applied mechanical stress.

The output voltages of the upper, middle, and lower sensors or transducers on different sleep areas generate observable voltage patterns.

“Skin-mountable wearable sensors for monitoring vital signs and biomedical parameters are components of great importance in personal healthcare and wearable diagnostic systems,” reports Ryou in Advanced healthcare materials. “Among them, thin-film piezoelectric sensors offer unique advantages: easy fabrication at low cost, a wide range of available sizes, light weight, excellent mechanical flexibility and stability, fast response speed, high sensitivity, high signal-to-noise ratio, and excellent stability and durability at long term.”

The new sensors are easy to wear and can be used in brain-eye relationship studies to evaluate the functional integrity of the brain.”

Jae-Hyun Ryou, associate professor of mechanical engineering, University of Houston

Intensive focus on illness

Ophthalmological assessments of eye blink patterns have been used for the early diagnosis of conditions such as stroke, multiple sclerosis, Parkinson’s disease, and Alzheimer’s disease. Also, eye movements are strongly linked to several brain disorders, as the controls of the eyeball and upper eyelid are affected by brain function.

Previous studies measured abnormal blink frequency and blink modulation in children with ADHD, with spontaneous blinking being a measure of the integrity of the brain’s dopaminergic system. Motor neurons in the brain, which involve the eyes and their muscles, have also been linked to autism.

“We believe that the F-PEMSA can be used in many clinical trials of brain disorders such as ADHD, autism, Alzheimer’s disease and Parkinson’s disease, as well as the aftermath of traumatic brain injuries such as post-concussion and post-traumatic stress disorder, which may offers the prospect of early and accurate diagnoses and the development of personalized therapies,” said Ryou.