The study authors say that wearing smartwatches or rings might not be a good idea for people with pacemakers or other implantable cardiac devices.
With the rapid rise in people owning smartphones, smartwatches, and other wearable devices, determining if these items can interact with pacemakers and other implantable devices becomes increasingly important.
Previous research has already determined that smartphones have the potential to interfere with cardiac implantable electronic devices (CIEDs) like pacemakers. Though, scientists say the risk is minimal if smartphones are kept at least 6 inches away from CIEDs.
However, whether smartwatches, rings, and scales have the same CIED-interruption potential is less clear.
Using benchtop experiments, researchers from the Department of Electrical and Computer Engineering at the University of Utah discovered that these smart devices could interfere with CIEDs. Their research was published on February 21 in the journal Heart Rhythm. The study authors say their findings provide evidence against using smartwatches, rings, and scales for people with pacemakers.
To examine the interference potential of the devices, the research team applied the same electrical current used in smartwatch bioimpedance sensors to three cardiac resynchronization therapy (CRT) devices from Boston Scientific, Medtronic (Minneapolis, MN), and Abbott (Chicago, IL) on computer-aided human models.
Bioimpedance sensing is what allows smart devices to measure a person’s vital signs, heart rate, blood oxygen levels, and stress levels when wearing them.
The team found that the bioimpedance sensing interfered with CIED functioning and emitted an electrical interference that exceeded the FDA’s accepted guidelines.
Moreover, the results suggest that wearables with bioimpedance sensing technology could generate an electric voltage higher than ISO 14117 maximum values for CIEDs — and this could occur without warning.
Still, the researchers note that while there’s no immediate or clear risk to people with pacemakers who wear smartwatches or rings, these wearables could cause heart-pacing interruptions or unnecessary shocks to the heart.
"Our research is the first to study devices that employ bioimpedance-sensing technology as well as discover potential interference problems with CIEDs such as CRT devices. We need to test across a broader cohort of devices and in patients with these devices. Collaborative investigation between researchers and industry would be helpful for keeping patients safe."
- Current Cardiology Reports. Interference by Modern Smartphones and Accessories with Cardiac Pacemakers and Defibrillators.
- Heart Rhythm. Safety evaluation of smart scales, smart watches, and smart rings with bioimpedance technology shows evidence of potential interference in cardiac implantable electronic devices.
- EurekAlert. Can smart watches and other fitness and wellness trackers do more harm than good for some people?