Is it safe to wear a personal alarm with a pacemaker? This is a common enquiry we receive from Aged Care Assessors and allied health professionals who support older adults.
To answer this question, Dr. José Argañarás, Umps’ Lead Hardware Engineer, recently undertook a literature review to summarise the research. In this article, we provide an overview of this research as well as recommendations so aged care professionals, their clients and family members can make a more informed choice about how they use a personal alarm.
Personal alarms, pacemakers and implantable cardiac defibrillators
Personal alarms, pacemakers and implantable cardiac defibrillators (ICDs) are used to protect the health and safety of older adults in different ways.
Personal Alarms
These are wearable devices that allow people to call for help in an emergency. They’re often used by older adults or people with medical conditions, enabling them to press a button if they need assistance, sending an alert to family members or emergency services.
Pacemakers
A pacemaker is a small, battery-powered device implanted in the chest to help control the heartbeat. Pacemakers monitor the heart's rhythms and adjust pacing as needed by sending electrical impulses to the heart.
Implantable Cardiac Defibrillators (ICDs)
Like pacemakers, Implantable Cardiac Defibrillators (ICDs) are implanted in the chest. ICDs monitor heart rhythms and deliver a quick electric shock if they detect dangerous, fast, or irregular heartbeats. This shock helps restore a normal heartbeat.
Understanding Electromagnetic Interference
Electromagnetic interference occurs when electronic devices send out energy waves that can disrupt how other devices work. For example, if you hold a mobile phone too close to a radio, you might hear static or buzzing sounds. This is because the phone's signals are interfering with the radio's signals. Electromagnetic interference is all around us and for most people, doesn’t cause any harm.
Why Electromagnetic Interference Matters for Pacemakers and ICDs
Pacemakers and ICDs can be disrupted by electromagnetic interference, similar to how a phone can interfere with a radio. Modern pacemakers generally have shields made from titanium designed to block interference. A person’s body also absorbs some of the interference. Despite these protections, there is a risk that electrical signals can still affect how pacemakers work [1].
What can happen if a pacemaker is exposed to electromagnetic interference?
A review by the Medical College of Virginia identified several ways that interference from strong electrical signals can affect a pacemaker [2]:
- Switch to ‘Noise Reversion Mode’: Some modern pacemakers have a Noise Reversion Mode that activates when they detect strong electrical signals. In this mode, the pacemaker keeps working but paces the heart at a fixed rate instead of adjusting to the heart's natural rhythm [3].
- Sending Extra Signals: Sometimes, a pacemaker may mistake interference for real heart activity, causing it to send extra signals to the heart. This can lead to a fast, irregular heartbeat and symptoms like a racing or irregular pulse.
- Switching to Backup Mode Without Notice: Electrical interference can sometimes make a pacemaker switch to a backup setting without the patient noticing. This is then typically discovered during routine check-ups, and usually, people don’t feel any symptoms from this change.
- Disruption to Operations: Electrical interference can also make a pacemaker stop sending signals, as it may mistake the interference for real heartbeats. This can cause the heart to pause temporarily, possibly leading to fainting. This is one of the most serious risks since it stops the pacemaker from working as needed.
- Damage to the Pacemaker: Prolonged or very strong exposure to electrical interference can physically damage the pacemaker’s parts, which would require a replacement. Symptoms from this kind of damage may or may not be noticed right away.
The potential malfunctions above can occur when a pacemaker is exposed to electromagnetic interference. However, an important consideration is whether a personal alarm can create enough interference to impact a pacemaker’s operation.
Do personal alarms create enough electromagnetic interference to impact pacemakers and ICDs?
While we couldn’t find any studies into the impact of personal alarms on pacemakers and ICDs, we did come across several studies investigating the compatibility of mobile phones on pacemakers and ICDs. These provide a useful reference point.
- One study undertaken at the University Hospital in Switzerland tested pacemaker interference by placing mobile phones in positions near a person’s pacemaker. The study found that while on standby or dialling, there wasn’t evidence that mobile phones interfered with pacemakers. However, during calls, 7 out of 39 people experienced disturbances with their pacemakers. This disturbance stopped when the phone was moved away [4].
- In a second study undertaken in Germany, no interference with pacemakers was identified. However, the researchers couldn’t rule out that pacemakers might be sensitive to electromagnetic interference [5].
- Recently, the National Institute of Health in Italy undertook a study on the impact 5G devices may have on pacemakers. The study showed that some 5G devices may interfere with pacemakers. The researchers advised that maintaining a distance of 15cm between a pacemaker and a mobile phone is sufficient to ensure this interference doesn’t disturb a pacemaker [6].
These studies indicate that while pacemakers handle electromagnetic interference well, certain types of interference in close proximity to a pacemaker may still pose risks.
How much electromagnetic interference does a Personal Alarm emit?
Different types of personal alarms are likely to emit different levels of electromagnetic interference due to specific technology used in their operation. The primary difference is between Home Based and Mobile Alarms.
Home Based Alarms
The good news is that Home Based Personal Alarms typically produce much less electromagnetic interference than mobile phones. With these alarms, a phone call is placed from a Hub in a person’s home. The Pendant Buttons worn as part of these alarms do not require constant data transmission over the mobile network, and as a result, they are likely to pose a lower risk of disrupting pacemaker operation. The added advantage of this is that the pendant is generally lighter and the battery lasts for several years without charging.
Mobile Alarms
In contrast, mobile alarms transmit signals through mobile networks, with the phone call placed directly from the device. This means they operate similar to a mobile phone, and are more likely to produce electromagnetic interference consistent with the studies above (while transmitting a call). While this interference is still generally minimal, it could impact pacemakers if the device is worn next to the chest.
Selecting the Right Personal Alarm for People with a Pacemaker
Choosing a personal alarm for someone with a pacemaker isn’t straightforward. Unfortunately, as the potential for interference relates to both the personal alarm and the pacemaker’s immunity to interference, you’re unlikely to get a straight confirmation from a manufacturer that a personal alarm is “safe” to wear around the neck.
Instead, when prescribing or selecting a personal alarm, keep in mind that:
- Home based alarms like the Umps Link Personal Alarm typically emit lower levels of electromagnetic interference than mobile alarms. They come with the added benefit of no daily charging, and are generally lighter and more comfortable to wear.
- Distance matters. Researchers suggest that keeping mobile devices at least 15 cm away from a pacemaker should be sufficient to mitigate any interference with a pacemaker.
Recommended Personal Alarms for People with a Pacemaker
Umps Link with Wrist or Belt Option
For a home-based solution, we recommend the Umps Link Personal Alarm, worn either on the wrist or using a belt-clip. The Umps Link Pendant doesn’t continuously transfer data over the mobile network, so is likely to emit less interference than a mobile alarm.
Umps Watch
For those needing a mobile personal alarm, the Umps Watch provides a safe option. As discussed, users should ensure that any mobile alarm device, including the Umps Watch, is kept at least 15cm away from their pacemaker to minimise any risk of interference. The Watch is worn on the wrist, making it easier to adhere to this distance.
Conclusion
In summary, while personal alarms generally produce low levels of electromagnetic interference, care should be taken when selecting and positioning them for people with pacemakers or ICDs. By choosing devices with minimal interference potential and maintaining a safe distance from the chest area, older adults can confidently use personal alarms without compromising the function of their cardiac devices.
References
- https://www.bostonscientific.com/en-US/patients-caregivers/device-support/pacemaker/emi.html
- https://oce.ovid.com/article/00045415-200107000-00004/PDF
- https://ecgwaves.com/topic/basic-cardiac-pacing-pacemaker-functions-and-settings
- https://www.sciencedirect.com/science/article/pii/0735109796000319
- https://pubmed.ncbi.nlm.nih.gov/8904534
- https://www.mdpi.com/1660-4601/20/5/4512#B14-ijerph-20-04512