Wi-Fi, a constant companion in our daily lives, may soon serve a purpose beyond just internet access. A research team at the University of California, Santa Cruz (UCSC) has developed a system that transforms everyday Wi-Fi networks into health monitoring tools. Without relying on any wearable devices, this technology can accurately measure heart rate using only Wi-Fi signals — potentially revolutionizing the way we approach health monitoring.

The team — consisting of Professor Chen-Nee Chuah, Ph.D. student Hamid Reza Karimi, and researcher Ramesh Bharadwaj — created a contactless, low-cost heart rate monitoring system called Pulse-Fi. The best part? It requires no special equipment beyond a typical home Wi-Fi setup.

How Does Pulse-Fi Work?

The researchers discovered that Wi-Fi signals are subtly affected by heartbeats, even without physical contact. The human body partially absorbs these signals, creating micro-changes in their waveform. Pulse-Fi uses an AI-powered algorithm to analyze these variations. It filters out environmental noise and focuses exclusively on heart rate fluctuations, delivering highly accurate results — often within seconds.

The system was trained using a custom AI model, developed under the guidance of Katia Obraczka, that effectively distinguishes between background movement and actual heartbeat signals, even if someone is walking around in the same room.

Clinical Accuracy at Pocket-Money Prices

Pulse-Fi delivers clinical-grade results with just 5 seconds of measurement time, showing a margin of error as low as ±0.5 bpm (beats per minute). Accuracy improves with longer readings. The system was tested on 118 volunteers across 17 different body positions — standing, sitting, walking, lying down — and remained reliable even when users were 3 meters (10 feet) away from the device.

What makes it even more appealing is the simplicity and affordability of the required hardware:

• ESP32 Wi-Fi module, or alternatively
• Raspberry Pi

Tests showed better results with Raspberry Pi, and the researchers suggest that even greater accuracy could be achieved using high-end commercial Wi-Fi hardware.

No Data? Create Your Own

Since no previous datasets existed for this kind of Wi-Fi-based heart rate monitoring, the team built their own. They collected Wi-Fi signal data via ESP32 and matched it with real-time heart rate data from standard pulse oximeters. This dataset was then used to train machine learning algorithms, enabling the current level of accuracy.

They also validated the system with a separate dataset from Brazil, developed using Raspberry Pi, and found consistent results.

Beyond Heart Rate: Breathing Detection on the Horizon

Pulse-Fi is not limited to heart rate monitoring. The team believes the same system can be adapted to detect respiratory rate — an innovation that could be a game-changer for tracking conditions like sleep apnea remotely and non-invasively. Though these results haven’t been officially published yet, early findings are promising.

Robotistan's Take: If There’s a Signal, There’s a Measurement

Today, we rely on our routers just to get online. But in the near future, they may also keep tabs on our vital signs. Pulse-Fi reimagines heart rate monitoring using everyday infrastructure like Wi-Fi.

The system's low cost, contactless measurement, high accuracy, and privacy-sensitive operating principle, combined with advanced health technologies, opens the door to more accessible and home-use-focused solutions. This approach, which could facilitate access to healthcare in developing regions, also holds great potential in elderly care, smart home systems, and patient monitoring applications.

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