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ZDNET Highlights
- Samsung’s Galaxy Watch can predict fainting events.
- False alarms and missed warnings remain a concern.
- More real-world testing is still needed.
Samsung wants you to know that its smartwatch can do more than just count your steps, track your sleep, and guilt trip you for not moving enough. The company has announced that its Galaxy Watch may be able to predict fainting episodes or blackouts before they even occur.
Samsung revealed this week that a joint clinical study Gwangmyeong Hospital of Chung-Ang University in Korea validated the Galaxy Watch 6’s ability to predict vasovagal syncope, or VVS. The study used the device’s photoplethysmography, or PPG, sensor to analyze heart rate variability data, then applied an AI algorithm to predict VVS during the head-up tilt test.
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Samsung calls this research “the world’s first study” demonstrating the ability of a commercial smartwatch to provide early prediction of fainting. The findings were published in European Heart Journal – Digital Health.
Why do early warnings matter?
Vasovagal syncope is one of the most common types of syncope, with “up to 40% of people” experiencing it in their lifetime, according to Professor Junhwan Cho of the Department of Cardiology at Chung-Ang University Gwangmyeong Hospital.
This happens when heart rate and blood pressure suddenly drop, often due to stress, dehydration, standing for too long, or some other trigger. Fainting in itself is not life-threatening, but a fall can result in a concussion, fracture, or other injury.
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“Injuries from sudden falls can be very real,” says Dr. Sam Setreh, director of cardiology and cardiovascular performance. Beverly Hills Cardiovascular and Longevity Institute told ZDNET. “Even a few minutes’ warning can be worthwhile: sit or lie down, hydrate, perform counterpressure maneuvers, or call for help. This can reduce falls, fractures, concussions, and other secondary injuries.”
This is where Samsung is bringing the Galaxy Watch and an early warning system into a potentially game-changing position.
Study and results
According to Samsung, the joint research team led by Cho evaluated 132 patients with suspected VVS symptoms during induced sedation tests. Using heart rate variability data from Samsung’s watch, the AI model predicted fainting events up to five minutes in advance with 84.6% accuracy. Samsung also said that the model reached 90% sensitivity and 64% specificity.
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Sensitivity refers to how often the system correctly catches true fainting events, while specificity refers to how often it correctly avoids false alarms. Looking at the numbers, a large number of alerts can be generated even when a person is not about to faint.
false positives
Dr. Brett A. Seelov, Chairman of Cardiology Hackensack Meridian Jersey Shore University Medical Center and vice chair of cardiology at Hackensack Meridian School of Medicine, said the 64% specificity is one of the biggest limitations of the study.
“In a controlled tilt-table lab, this might be acceptable,” he said, but in the real world, where millions of watch users are going through daily life, “that false-positive rate can generate a huge amount of unnecessary alerts.”
Setareh also cautioned that the study was conducted in a controlled tilt-table lab, in which researchers observed patients in a setting designed to provoke symptoms, not in a broader real-world consumer setting where users were living normal lives. Everyday factors such as “motion artifact, hydration status, posture, medications, sleep, alcohol, anxiety and other variables” can affect the signals, he said.
He added: “Too many false positives can lead to anxiety, alarm fatigue and unnecessary medical evaluations.”
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The study population was also highly specialized, Seelow said. Each participant, he said, was “undergoing an intentionally stimulating laboratory procedure designed to induce unconsciousness (or a blackout phenomenon).” The participants were also suspected of having neurally-mediated unconsciousness, meaning the findings do not show how the algorithm would perform in someone without that history.
“The study doesn’t tell us anything about how this algorithm will perform in someone who has never had a tilt-table test, who has no documented history of vasovagal syncope, or who is simply going about their daily life,” Seelow said.
false assurance
False reassurance is another risk, warns board-certified neurologist Dr. Rab Nawaz Khan my migraine teamA health startup based in San Francisco. “If a watch doesn’t warn someone, it doesn’t mean they’re safe,” he said. “People with chest pain, palpitations, seizure-like activity, neurological symptoms, fainting associated with injury or exertion still need medical evaluation.”
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In other words, one should not assume that everything is fine, or ignore frequent fainting just because their watch was not ringing.
Dr. Setreh agreed, “Normal smartwatch readings should not lead one to ignore frequent fainting, chest pain, anxiety, exertional symptoms, or neurological symptoms.”
Not a replacement for medical evaluation
For now, the most realistic role for such a smartwatch feature seems to be as an additional warning layer for people who already suffer from frequent vasovagal syncope. In that scenario, a few minutes’ warning may be enough time for someone to sit up, lie down, call for help, or move away from the stairs, traffic, or another unsafe place.
But it must be accurate enough to help without causing panic, creating a false sense of security, or causing people to ignore alerts. It should work alongside medical care, not instead of it. According to Setreh, the important part of the study isn’t that Samsung’s watch diagnoses fainting like a doctor. It is that it may be picking up a physical pattern before an event.
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“Consumer smartwatches are certainly becoming legitimate preventive health tools, but they are not yet a replacement for medical evaluation,” he said. “Their best role is as an early-warning and risk-awareness layer.”
Khan also shared similar sentiments. “My view is that consumer smartwatches are becoming legitimate health-support devices, but they are not clinical replacements for physicians,” he said.
Seelow said Samsung’s study is still notable because it used a commercial smartwatch rather than a medical-grade device, calling it a “meaningful milestone.” Still, he cautioned that although wearable devices are useful for collecting physiological data, they are not designed to diagnose most conditions or suggest treatments.
More study is needed
Seelov reiterated that Samsung’s study does not yet validate the Galaxy Watch as a preventive device for the general population.
It’s one thing to predict the occurrence of fainting during a controlled tilt-table test. It is a very difficult challenge to predict when someone is cooking breakfast, standing on a crowded stage, walking outside in the heat, or getting up during the night.
“The leap from ‘this works during induced anesthesia in the point-of-care laboratory’ to ‘this will keep my grandmother safe in her kitchen’ is huge, and that gap can only be filled by large, multicenter, real-world ambulatory trials,” he said.
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Both Setreh and Khan also suggested that the next step is real-world validation.
The new studies should answer practical questions: Does the feature work when people are moving, overheated and sweating, not sleeping well, drinking alcohol, taking prescriptions, or wearing the watch loosely? Does it perform equally well across age, skin color and health issues? And do alerts actually prevent injuries, or do they create noise? Only more data can answer.
“Larger, multicenter studies are needed across different populations, devices, skin colors, activity levels, and episodes of spontaneous syncope,” Setareh said. “We also need to know whether alerts actually reduce injuries.”
“If validated in larger real-world studies, this type of technology could become a useful preventive tool for people with frequent vasovagal syncope,” Khan said.
coming soon? not so fast
Samsung did not say how it plans to use the results of this study. It only says that the study demonstrates the “ability to detect fainting early” using the Galaxy Watch and that it paves the way for real-time warning systems.
Currently, there is no timeline for rolling out the faint detection feature to the wider public.
