Your Wi-Fi Can Now Listen to Your Heartbeat—No Wearables Required
Imagine this: you’re lounging on your couch after a long day, and without strapping on a smartwatch or clipping on a pulse oximeter, your heartbeat is being monitored in real time—by your Wi-Fi router. Sounds like sci-fi? It’s not. Thanks to a breakthrough from researchers at the University of California, Santa Cruz, your everyday Wi-Fi signals might soon double as a silent, invisible health guardian.
Meet Pulse-Fi—a clever, low-cost system that turns ambient Wi-Fi into a contactless vital signs monitor. Developed by Professor Katia Obraczka and her team, including postdoc Nayan Sanjay Bhatia and high school intern Pranay Kocheta, Pulse-Fi detects the subtle chest movements caused by your heartbeat by analyzing tiny fluctuations in Wi-Fi signal amplitude. No cameras. No wearables. Just the invisible waves already bouncing around your home.
Why This Matters
Traditional heart rate monitoring often relies on wearables—devices that can be uncomfortable, expensive, or simply forgotten on the nightstand. Camera-based systems offer a contactless alternative but falter in low light and raise serious privacy concerns (who wants their webcam watching them 24/7?). Pulse-Fi sidesteps both issues. It works in the dark, respects your privacy, and runs on hardware that costs as little as $5–$10 (ESP32 microcontrollers) or $30 (Raspberry Pi).
In lab tests, Pulse-Fi achieved an error rate of less than 1.5 beats per minute—on par with clinical-grade reference devices. It remained accurate whether participants were sitting, standing, walking, or even running in place, and worked reliably up to 10 feet away.
Even more impressively, the AI model behind Pulse-Fi isn’t just regurgitating training data—it generalizes well to new environments, meaning it can adapt to real-world settings it’s never seen before. That’s a big deal for practical deployment in homes, hospitals, or senior care facilities.
The team has only tested single-person scenarios so far, but they’re now piloting multi-user detection and exploring applications beyond heart rate—like monitoring breathing patterns and detecting sleep apnea.
What’s Next?
Obraczka’s team is already laying the groundwork to commercialize Pulse-Fi, envisioning a future where your smart home doesn’t just control lights and thermostats—it keeps an eye on your health, quietly and continuously.
Glossary
- Wi-Fi Signal Amplitude: The strength or intensity of a Wi-Fi radio wave; tiny changes in amplitude can be caused by physical movements, like the rise and fall of your chest during a heartbeat.
- ESP32: A low-cost, low-power microcontroller chip commonly used in IoT (Internet of Things) projects; supports Wi-Fi and Bluetooth.
- Pulse Oximeter: A medical device that clips onto a fingertip to measure heart rate and blood oxygen levels—used here as a benchmark for accuracy.
- Contactless Monitoring: Health tracking that doesn’t require physical contact with the body, enhancing comfort and usability.
- Generalization (in AI): The ability of a machine learning model to perform accurately on new, unseen data—not just memorizing training examples.
Source: IEEE Spectrum – Wi-Fi Signal Heartbeat Detection
