By Dave DeFusco

In a UNC-Chapel Hill neuroscience lab, researchers recently monitored a mouse wearing a miniature, helmet-like device that streamed real-time data to a nearby computer. As data points on heart rate, pupil size and breathing patterns scrolled across the screen, capturing the intricate interplay between animal physiology and behavior, they realized that their device was more than just another research tool but a groundbreaking advancement in behavioral science—one where internal physiological states can finally be measured with precision, potentially revolutionizing several fields from preclinical and clinical neuroscience research to virtual reality.

For Dr. Jose Rodriguez-Romaguera, a neuroscience researcher in UNC’s Psychiatry Department, the journey toward this breakthrough began with a simple but elusive goal: to understand how neural circuits regulate arousal in animals and humans. In his research, he found that arousal—the body’s way of regulating alertness, stress and emotion—is central to a wide range of psychiatric disorders. People experiencing depression, anxiety, PTSD and autism all exhibit disruptions in arousal patterns, yet these internal states can only be observed through external behaviors, such as a patient’s behavior in a clinician’s office or surveys about their experiences.

“Clinicians rely heavily on observation to diagnose arousal-based disorders,” said Dr. Rodriguez-Romaguera, “but the reality is, we haven’t been able to precisely measure these internal states in real-time over long periods. That’s where we come in.”

Dr. Rodriguez-Romaguera’s collaboration with Dr. Nicolas Pégard, an optical engineer in the Department of Applied Physical Sciences, has enabled the development of a custom device to meet the rigorous needs of neuroscience researchers. Their flagship innovation, known as ocular photometry, is a groundbreaking technology that can monitor multiple arousal metrics in real time. Inspired by pulse oximetry, which measures oxygen levels with light, the team has adapted the concept to track multiple physiological signals through the eye.

“This new tool leverages principles of infrared light to precisely monitor arousal states by capturing a wealth of data on heart rate, respiration and pupil dynamics,” said Dr. Pégard, “allowing researchers to monitor arousal levels continuously with unprecedented precision.”

The journey from concept to working device was driven by a team of trainees in the labs of Pégard and Rodriguez-Romaguera, with Ellora McTaggart playing a pivotal role. A graduate of the UNC-NC State Joint Department of Biomedical Engineering, McTaggart has managed both labs for three years. In her role as lab manager, she helped develop the first wearable prototype, specifically designed for rodents and allowing for free movement—a significant achievement in neuroscience technology.

“This was about taking an ambitious idea and making it usable, practical and adaptable,” she said.

The potential of ocular photometry extends far beyond the lab and into clinical and commercial applications that could redefine existing technologies for humans. The team is designing a human prototype to be as simple and unobtrusive as a pair of glasses, with data streaming wirelessly to smartphones via Bluetooth for real-time arousal tracking.

“People can wear the glasses throughout the day without feeling burdened by the technology,” said Dr. Pégard.

Tracking arousal fluctuations in real time would allow clinicians to adjust treatments dynamically, perhaps even delivering alerts to patients to help them self-regulate their emotional states. For caregivers and families of individuals with developmental disabilities, the device could provide insights into moments of overstimulation or disengagement, enabling more responsive support. In sleep studies, ocular photometry holds potential for mapping complex arousal patterns and providing deeper insights into sleep disorders than traditional tools.

“The versatility of the technology doesn’t end there,” said McTaggart. “In virtual reality, it could enhance user experiences by dynamically adapting the environment based on real-time arousal and gaze data, allowing the system to render only what the user sees directly.”

Recognizing the technology’s broad potential, Rodriguez-Romaguera, Pegard and McTaggart co-founded Carolina Instruments, a UNC-affiliated startup focused on getting ocular photometry out of the lab. McTaggart leads the company with the mission to get this powerful technology into the hands of researchers and clinicians who can use it to make groundbreaking discoveries. The company recently secured an NC IDEA grant to develop a commercial version of its device, marking a major milestone in its growth.

For the team, the heart of the project is its potential clinical impact. Dr. Rodriguez-Romaguera said their greatest excitement lies in empowering clinicians and patients with tools to understand mental health in ways previously unimaginable.

“Right now, if you’re being evaluated for depression or anxiety, the diagnosis is based largely on what you say you’re feeling and what the clinician can observe,” said Dr. Rodriguez-Romaguera. “But imagine if we could combine that with data from a full day—how your arousal changes and how your body responds to stress or joy in real-time.”

With their first Institutional Review Board approval secured and a goggles-based prototype ready for testing, the team has set its sights on securing grants, navigating clinical trials and refining the technology for everyday use.

“We’re not just building a device,” said Dr. Pégard, “we’re building a bridge between neuroscience, technology and human well-being. And that bridge could change everything.”