How Wi-Fi Can “Hear” Your Heartbeat: The Science Behind Pulse-Fi Contactless Monitoring
In the age of smartwatches and fitness trackers, most of us think of heart-rate monitoring as something you wear — a strap, a band, or a patch that measures your pulse through skin contact. But what if your Wi-Fi router could do the same job, without touching you at all?
It might sound like science fiction, but researchers at the University of California, Santa Cruz have turned this into reality. Their new system, called Pulse-Fi, can detect your heartbeat using ordinary Wi-Fi signals — no sensors, no straps, no wearables. This innovation could change how we monitor health at home, in hospitals, and even in public spaces.
Let’s break down how it works, why it matters, and where this technology could take us next.
What Is Pulse-Fi?
Pulse-Fi is a contactless heart-rate monitoring system that uses existing ambient Wi-Fi signals — the same kind that connect your phone or laptop to the Internet — to measure your heartbeat.
Instead of sending out special medical signals, it listens to the tiny ripples that your body causes in the Wi-Fi waves as your heart beats. Those microscopic disturbances can be captured, filtered, and analyzed by artificial intelligence to estimate your pulse in real time.
In short: your heartbeat slightly changes the Wi-Fi signal around you, and with smart enough algorithms, that change can be turned into a pulse reading.
Why Wi-Fi Heartbeat Detection Is Revolutionary
Monitoring vital signs like heart rate and breathing is crucial for detecting stress, dehydration, cardiac disease, and other health issues early. Traditionally, this means wearing something — from a smartwatch to a chest strap — or being hooked up to hospital monitors.
That’s not always practical.
1.Wearables can be uncomfortable or irritating for long-term use.
2.Adherence is low: people forget to wear them or take them off at night.
3.Cost can be a barrier, especially for medical-grade devices.
Pulse-Fi avoids all of these issues. Because it uses signals already present in the room, it’s:
1.Completely contactless — you don’t have to touch or wear anything.
2.Low-cost — the hardware costs as little as $5 to $30.
3.Accessible — it can work anywhere Wi-Fi is available.
That means this technology could bring health monitoring to homes, nursing centers, workplaces, and even developing regions without expensive medical infrastructure.
How Can Wi-Fi Measure a Heartbeat?
It may seem impossible that something as faint as a heartbeat could affect Wi-Fi waves. But here’s the science behind it.
Wi-Fi works by transmitting radio waves through the air. When those waves encounter a moving object — even the slight rise and fall of your chest or the tiny vibration caused by your heartbeat — the signal changes subtly. These signal changes are reflected back to the Wi-Fi receiver.
The Pulse-Fi system listens for those minute fluctuations and separates them from all the background noise — things like other people moving, objects in the room, or random electronic interference.
Here’s what happens step by step:
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Signal Capture: Pulse-Fi uses inexpensive devices (like ESP32 chips or Raspberry Pis) to read Wi-Fi signal data.
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Noise Filtering: The system removes background interference, isolating the tiny, rhythmic changes that match a heartbeat pattern.
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AI Analysis: A lightweight artificial intelligence model analyzes these filtered signals and calculates the user’s pulse rate in real time.
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Display: The heart rate is displayed or transmitted to a monitoring system — all without any physical contact.
This process happens continuously, allowing Pulse-Fi to monitor a person’s heartbeat passively as long as Wi-Fi is available.
Testing the Technology: What the Experiments Showed
The UC Santa Cruz research team — led by Professor Katia Obraczka along with postdoctoral researcher Nayan Sanjay Bhatia and high-school intern Pranay Kocheta — ran a series of tests to prove that Pulse-Fi really works.
Experiment 1: Distance and Accuracy
Seven volunteers sat at distances of 1, 2, and 3 meters (about 3 to 10 feet) from two Wi-Fi devices running Pulse-Fi. Their pulse readings were compared to standard medical devices called pulse oximeters.
Result:
Pulse-Fi’s readings had an average error of less than 1.5 beats per minute, nearly matching the accuracy of the reference sensors.
Experiment 2: Movement and Posture
Next, the researchers tested more than 100 participants doing everyday activities — walking, sitting, running in place, or standing still.
Result:
The system stayed accurate even when people moved or changed posture. It also worked up to 10 feet away, proving that the Wi-Fi signal could capture vital signs across a small room.
These findings were presented at the 2025 International Conference on Distributed Computing in Smart Systems and the Internet of Things, where Pulse-Fi drew attention for its simplicity and real-world potential.
Small Hardware, Big Potential
One of Pulse-Fi’s biggest advantages is that it doesn’t require specialized hardware. The team designed it to run on simple computing devices such as the $5–10 ESP32 microcontroller or the $30 Raspberry Pi mini-computer. These are cheap, widely available, and easy to integrate into smart home devices or routers.
That means in the future, this technology could be built directly into:
1.Smart routers that track your health automatically.
2.Home security systems that detect not just motion, but breathing and heartbeat.
3.Elder-care systems that alert caregivers if someone’s heart rate suddenly drops.
4.Hospital rooms that monitor patients wirelessly, reducing cables and discomfort.
Because the AI model used in Pulse-Fi can generalize to new environments — meaning it doesn’t have to be retrained every time — it’s highly adaptable for real-world applications.
Contactless Heart-Rate Monitoring vs. Traditional Wearables
Let’s compare Pulse-Fi with the most common wearable devices people use today.
| Feature | Wearable Devices | Pulse-Fi (Wi-Fi-based) |
|---|---|---|
| Contact with Body | Required | None |
| Comfort | May irritate or be forgotten | Fully passive |
| Cost | $100+ for good accuracy | <$30 setup |
| Power Needs | Must be charged regularly | Plugged into power or router |
| Accuracy | High | Comparable |
| Privacy | Personal data stored on app | Wi-Fi data must be secured |
| Range | Only tracks wearer | Can track person within 10 ft |
Pulse-Fi’s contactless nature makes it ideal for long-term health tracking, especially for elderly people, patients in hospitals, or anyone who struggles with wearable compliance.
Potential Uses for Pulse-Fi and Similar Technologies
While Pulse-Fi is still in research and testing stages, its possibilities are wide-ranging.
1. Home Health Monitoring
Imagine coming home from work and your Wi-Fi quietly checking your heart rate and breathing in the background. It could flag early signs of stress, fatigue, or irregular heartbeat before you even notice symptoms.
2. Sleep Tracking
Unlike cameras or wearables that can be intrusive, a Wi-Fi-based system could monitor your sleep quality and breathing completely contact-free — useful for detecting sleep apnea or nighttime irregularities.
3. Elderly Care
For seniors living alone, Pulse-Fi could provide passive safety monitoring. If it detects a sudden drop in heart rate or abnormal rhythm, it could send an alert to caregivers or family members.
4. Hospital Applications
Hospitals could deploy Wi-Fi health monitoring systems in wards to track patients continuously without the need for multiple wired sensors, reducing clutter and improving comfort.
5. Workplace Wellness
In office settings, Wi-Fi health tracking could be used (with consent) to monitor employee well-being — spotting early signs of stress or fatigue.
What About Privacy and Security?
As exciting as Wi-Fi health monitoring sounds, it also raises important privacy and ethical questions.
Since Wi-Fi signals can now detect biological activity, what’s to stop someone from using them to monitor others without consent? Researchers are aware of this risk and emphasize that data security must be built into the system from the start.
Potential safeguards include:
1.Data encryption of all Wi-Fi signal readings.
2.On-device AI processing, so raw health data never leaves your home.
3.User consent before activation.
4.Strict regulation for medical-grade implementations.
Just like cameras or smart speakers, contactless monitoring tools must balance innovation with privacy protection.
What Are the Current Limitations?
Even though Pulse-Fi’s early results are promising, the technology isn’t perfect yet.
1.Single-User Environment:
Current prototypes can only track one person at a time. The research team is now exploring multi-user detection to handle group settings or family environments.
2.Signal Interference:
Physical obstacles or other wireless devices can distort readings. Calibration may be needed in complex spaces.
3.Limited Metrics:
Right now, Pulse-Fi measures mainly pulse rate. Future versions may detect respiratory rate, heart rate variability, or even emotional stress indicators.
4.Regulatory Approval:
To be used as a medical device, it must go through strict validation and certification processes.
Despite these challenges, the concept has enormous potential to complement — not replace — existing health-tracking methods.
The Future of Wireless Health Tracking
Pulse-Fi is part of a broader trend toward ambient health technology — systems that monitor your well-being without you having to do anything.
In the next decade, we could see:
1.Smart homes that track residents’ heart rates, breathing, and sleep through Wi-Fi.
2.AI-powered routers that double as personal health hubs.
3.Non-invasive hospital systems that rely on radio signals rather than electrodes.
Combine this with advances in machine learning, edge computing, and IoT, and Wi-Fi-based health tracking could become as common as temperature sensors or motion detectors today.
Key Takeaways
Pulse-Fi is a breakthrough system that uses Wi-Fi signals to measure heart rate — completely contactless and low-cost.
It’s as accurate as traditional pulse sensors, with less than 1.5 beats-per-minute error.
The system runs on affordable hardware like ESP32 chips and Raspberry Pis.
Potential uses include home health monitoring, elderly care, sleep tracking, and hospitals.
Privacy and multi-user accuracy are ongoing challenges, but the future looks promising.
Final Thoughts
The idea that your Wi-Fi can “hear” your heart might sound futuristic, but it’s quickly becoming reality. Pulse-Fi represents a shift from wearable technology to invisible, ambient health tracking — where your environment itself becomes a silent caretaker.
Just as Wi-Fi transformed how we connect to the world, it might soon transform how we understand and protect our health.
As this technology evolves, one thing is clear: in the near future, your home network won’t just know your download speed — it might also know how fast your heart is beating.