For people with autism, aggressive outbursts may be the only external signs of stress that’s been building up inside — seemingly unpredictable moments that can startle even their trusted caretakers. But there are more subtle signs of distress that wearables can detect and communicate in advance, a Northeastern University research team has discovered, offering caregivers a precious minute of advance awareness to prepare for and possibly mitigate the issue.

The fundamental challenge is in helping people with autism to communicate their distress to caregivers before it reaches the boiling point of an outburst, an issue due to the high resting levels of stress and verbal communication challenges some people face. To an outside observer, the outburst might appear to come from nowhere, even though an unspoken stressor was quietly ratcheting up the tension.

To measure the stress leading to episodes, Northeastern professor Matthew Goodwin developed a wearable that monitors a person’s heart rate, sweat production, skin temperature, and arm movements, all synchronized to a clock so that changes can be mapped to specific times when outbursts occurred. After 87-hour initial tracking periods, Goodwin’s data was able to predict future aggressive outbursts one minute in advance with 84% accuracy.

That one-minute timeframe notably isn’t a maximum; Goodwin suggests it’s just a starting point based on the current state of his research. His team initially studied only 20 children with autism, and is now expanding the sample size to 240 people, with plans to use better data and more sophisticated machine learning models to achieve longer periods of early awareness.

Assuming the wearable achieves general release, it could dramatically improve quality of life for both people with autism and their caregivers. A caregiver alerted to signs of distress could rush in to soothe or remedy the provoking situation, eliminating the outburst altogether. Similarly, a constantly fearful caregiver could start to enjoy a more normal social life rather than worrying about disrupting public spaces.

“Families with children who act aggressively tell us that they don’t know what causes these outbursts,” said Goodwin, “and they’re fearful it could happen anytime, so they self-impose house arrest. They don’t go to the movies. They don’t go to the grocery store with their kids. They don’t go to parks.” Some parents have indicated that even 60% accuracy on advance outburst awareness would be a “priceless” improvement over their current situations, where luck is the only thing that may help them discover a problem before it occurs.

There’s no release timeline yet for the wearable, but testing is continuing thanks to funding from the Department of Defense and two private foundations. By the time the studies are complete, it’s possible that sensors in general-purpose wearables may have caught up with the technologies used in Northeastern’s research, enabling users to obtain the benefits through smartwatch and smartphone apps.