Is Your Fitness Band Affected by Train Emissions?
Did you know that your fitness band, smartwatch, or even an NHS-approved Holter monitor could be affected by electromagnetic emissions from trains? As cities move towards electrified transportation, electromagnetic interference (EMI) is becoming a real issue, one that most people never even think about. We are constantly surrounded by electromagnetic pollution from power grids, transport systems, and wireless networks. But what happens when this interference starts messing with something as important as heart monitoring?
The Hidden EMI in Our Cities
This became the focus of my research, and what I found was unexpected. Trains and trams can interfere with ECG readings, potentially leading to misinterpretations of heart activity.
A Holter monitor is a portable ECG device used by hospitals to track heart rhythms over 24 to 48 hours, helping diagnose conditions like atrial fibrillation and ventricular tachycardia. It’s often prescribed when a standard ECG isn’t enough to catch intermittent heart problems. But here’s the issue, Holter monitors rely on electrodes attached to the skin, and these are extremely sensitive to external electrical and magnetic fields. If EMI from a train couples into these electrodes, it can introduce noise, causing false arrhythmia detections or, worse, masking actual cardiac abnormalities.
Testing the Impact: Can Trains Really Affect ECG Monitors?
I wanted to see for myself whether electrified railways actually interfere with ECG monitoring devices. So, I ran tests with wearable ECG monitors in different environments.
I placed them inside an electric train to measure direct EMI exposure, near railway tracks to see how distance impacts interference, and in a controlled lab setup to compare clean ECG readings with EMI-affected ones.
The results were surprising. In high-EMI areas, ECG signals became unstable, showing distortions and irregularities that weren’t there in EMI-free conditions. This confirmed that railway EMI can affect ECG monitoring, making some wearable and medical ECG devices unreliable in transport zones.
Fixing the Problem: Smarter ECG Analysis with AI
To fix this, I developed an intelligent ECG anomaly detection system using MATLAB. The goal was simple: help doctors and wearable device users tell the difference between real heart conditions and EMI-induced noise, without needing to be a coding expert.
This system analyzes ECG amplitude, heart rate variability, and frequency signatures to detect abnormal rhythms like atrial fibrillation, ventricular tachycardia, and premature ventricular contractions. The tricky part is that some railway-induced EMI artifacts look just like real arrhythmias, making it hard to separate false alarms from serious conditions.
By using advanced filtering and AI-driven pattern recognition, my algorithm can:
- Remove EMI distortions while keeping real heart signals intact
- Detect and classify arrhythmias with 85 percent accuracy
- Provide a user-friendly visual interface, so even non-experts can see how EMI affects ECG readings and how corrections are applied
This is a step toward smarter ECG filtering, ensuring that heart monitors remain reliable even in electrified environments. Because when it comes to heart health, accuracy matters.
Why This Research Matters
If you use a fitness tracker, smartwatch ECG, or Holter device, this research raises an important question: how reliable is your heart reading in an urban setting? Whether you’re a heart patient, an athlete, or just someone keeping an eye on their health, knowing that wearable ECGs can be affected by railway EMI is something to consider.
But this isn’t just about personal health tracking. It also raises bigger concerns about medical technology. Are current regulations strong enough to protect biomedical devices from railway EMI? Right now, railway EMC standards don’t fully cover low-frequency emissions, which means many wearable and medical ECG devices could be vulnerable in certain locations.
Final Thoughts
Electromagnetic interference is an invisible but serious challenge for wearable ECG monitoring, especially for medical devices like Holter monitors that people rely on for critical diagnoses. My research highlights an issue that many doctors, engineers, and wearable tech users may not have considered before.
So next time you’re on a train wearing a smartwatch ECG or a Holter monitor, remember—there’s more happening around you than you might think.