Imagine checking your heart rate without strapping on a smartwatch or chest monitor. This future might not be far off.
Engineers at the University of California-Santa Cruz developed a system that uses Wi-Fi signals to monitor heart rate without the need for smartwatches, chest straps or other wearables. The project, known as Pulse-Fi, shows in early data that ordinary wireless devices can be repurposed as accurate health sensors.
"Non-intrusive monitoring of vital signs such as heart rate is critical to improving elderly care and early health intervention," the study says. "Long-term care and healthcare institutions increasingly need systematic, continuous accuracy that is easy to deploy. Wi-Fi signals offer unique advantages: they penetrate walls, are ubiquitous indoors and avoid camera-based privacy concerns."
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What is Pulse-Fi?
Pulse-Fi works by taking advantage of how Wi-Fi signals interact with the body. Each time a signal passes through, the heartbeat creates subtle ripples that slightly alter the wave. The system can capture these tiny disturbances by setting up a transmitter to send the signal and a receiver to collect what comes out the other side. From there, a machine-learning model, which is trained on data from more than a hundred volunteers in different positions, filters out the noise and pinpoints the variations tied to the pulse.
What makes the approach so compelling is its simplicity. The researchers showed that even inexpensive hardware, such as a $30 Raspberry Pi or a $5 ESP32 Wi-Fi module, is powerful enough to run the system. In testing, Pulse-Fi could read heart rate within half a beat per minute after only five seconds. It stayed clinically accurate whether participants were sitting, standing or lying down, and it worked at distances of up to three meters.
The implications of this research could be significant. Wearable devices and hospital monitors provide reliable heart-rate readings but are often expensive or inconvenient. Pulse-Fi relies on hardware that costs less than $30, which makes it practical for homes, clinics and low-resource settings. Because the process is completely contactless, it could be particularly useful for older adults, patients in recovery or people who dislike or cannot tolerate wearing sensors.
The research team is already expanding the system to measure breathing and explore applications for conditions such as sleep apnea. Longer term, the technology could turn home Wi-Fi setups into passive health monitors, offering continuous feedback without requiring people to change their routines.
Pulse-Fi was presented at the 2025 International Conference on Distributed Computing in Smart Systems and the Internet of Things conference held in Tuscany, Italy. What started as a university project now points to a future where our homes are equipped with invisible health sensors powered not by expensive gadgets, but by the Wi-Fi we already use every day.
Read also: Is Your Heart Rate Healthy? Here's How to Find Out