Wi‑Fi heart rate monitoring: UCSC’s Pulse‑Fi turns ordinary Wi‑Fi into a contactless pulse detector
Scientists at the University of California, Santa Cruz have developed Pulse‑Fi, a contactless system that uses standard Wi‑Fi and machine learning to detect heart rate with near‑clinical accuracy up to about 10 feet, using low‑cost hardware.
Key takeaways
- Contactless monitoring: Pulse‑Fi reads tiny heartbeat‑related changes in Wi‑Fi signals using standard transmitters and receivers and a neural network (UCSC).
- High accuracy fast: Early tests report about 0.5 beats per minute average error after five seconds, improving with longer windows or better hardware (Tom’s Hardware; UCSC).
- Low cost, practical range: Works up to ~10 feet and runs on inexpensive chips such as ESP32 or slightly pricier boards like a Raspberry Pi for better performance (Tom’s Hardware).
How Pulse‑Fi works
Pulse‑Fi leverages how Wi‑Fi radio waves interact with the human body. Standard Wi‑Fi devices continuously emit radio waves; the subtle chest motion and tissue displacement caused by each heartbeat slightly alters those signals. These variations are normally imperceptible.
The UCSC team paired a Wi‑Fi transmitter and receiver so the receiver logs minute signal changes. They then trained a machine learning model by synchronizing those Wi‑Fi logs with pulse oximeter “ground truth” readings. The model learns which features indicate heartbeats and which are noise (UCSC; Tom’s Hardware).
Why machine learning matters
Because heartbeat effects on Wi‑Fi are extremely small and easily masked by other movements or household objects, the team applied data‑driven filtering. A neural network identifies the characteristic heartbeat signature amid competing signal shifts, enabling robust readings while users move, change posture, or vary distance.
Performance and tests
In lab and household trials, Pulse‑Fi reached near‑clinical accuracy: average error near 0.5 bpm after five seconds, with error decreasing over longer observation periods or with higher‑end Wi‑Fi hardware. The system reliably worked at distances up to about 10 feet and during everyday activities (UCSC; Tom’s Hardware).
Training data and datasets
Because no public dataset matched this specific task, researchers built custom datasets by collecting synchronized Wi‑Fi signal logs and oximeter readings for training and validation. That bespoke approach enabled the model to distinguish heartbeat features from environmental noise (UCSC).
Hardware and cost
A major appeal of Pulse‑Fi is its affordability. The proof‑of‑concept used low‑cost ESP32 chips (~$5–$10). Employing boards like a $30 Raspberry Pi can sharpen accuracy modestly. This low entry cost makes the approach promising for home and low‑resource settings (Tom’s Hardware; UCSC).
Beyond heart rate: respiratory signals and potential diagnostics
Early results indicate Pulse‑Fi may also capture respiratory rate and breathing patterns that could relate to sleep apnea. These findings are preliminary and not yet validated for clinical use, but they suggest broader potential for Wi‑Fi‑based vital sign monitoring (UCSC).
Research presentation and interest
The UCSC team presented Pulse‑Fi at the 2025 IEEE International Conference on Distributed Computing in Smart Systems and the Internet of Things (DCOSS‑IoT). The group encouraged industry collaboration and commercialization, drawing coverage from tech outlets and science press (ENN; UCSC).
Questions and challenges
Remaining limits: Trials were mainly controlled and in limited household settings. Wider real‑world testing across diverse homes, body types, and environments is required.
Privacy and policy: Passive sensing via Wi‑Fi raises legal and ethical questions about who can collect, store, and act on vital signs without clear consent. The UCSC team’s call for industry partners increases the urgency of governance conversations (UCSC).
How this differs from wearables
Unlike smartwatches or chest straps, Pulse‑Fi requires no physical contact, eliminating charging and wearing burdens. That can benefit people unwilling or unable to use wearables and enable continuous, hands‑free room monitoring—useful for home care or elder care. Wearables, however, still measure metrics such as blood oxygen saturation that Pulse‑Fi does not yet provide (UCSC; Earth.com).
Implications for San Diego, California
Economic impact: San Diego’s biotech, wireless, defense, and medical device clusters could see startups and manufacturers adopt low‑cost Pulse‑Fi modules and integrated home‑health solutions, creating local demand (UCSC).
Healthcare delivery: Home health providers and hospital systems in San Diego County might use contactless monitoring to reduce clinic visits and enable remote checks for patients without issuing wearables (UCSC).
Regulatory and policy concerns: Local regulators and privacy advocates will likely weigh in on standards for informed consent, data security, and permissible uses in care environments and public housing (UCSC).
Social effects: Contactless monitoring could ease caregiving burdens but also reshape expectations about in‑home surveillance—prompting residents and consumer groups to demand clear disclosure rules (ENN).
Community relevance: San Diego’s maker and academic communities may adopt Pulse‑Fi for research, public health pilots, and hobbyist projects; UCSC’s open presentation invites collaboration and local trials (UCSC).
Practical applications: Households could monitor elderly relatives, screen for sleep breathing issues, or run quick contactless checks after exercise—provided clear rules govern data storage and use (Earth.com).
Sources and coverage
Primary project summary and technical details: UCSC.
Independent reporting and analysis: ENN; Tom’s Hardware; Earth.com.
Technical overview of signal behavior and related methods: technical overview.
“Pulse‑Fi demonstrates that ordinary Wi‑Fi can become a practical sensor for vital signs, but broader trials, privacy safeguards, and regulatory guidance are essential before widespread deployment.”
— UCSC research presentation at DCOSS‑IoT 2025 (UCSC)
Note to readers and decision makers: Pulse‑Fi is an exciting technical advance that opens practical opportunities and regulatory debates. As lab demonstrations evolve into pilots, monitor local trials, privacy policies, and device standards before adopting contactless Wi‑Fi health sensing.
