WiFi signals can measure heart rate

Non-contact health monitoring appeal

• Many are excited about passive heart-rate and respiration tracking for sleep, exercise, and elder care, without wearables or wires.
• Caregivers see value for patients who won’t reliably wear devices (e.g. dementia, frail elders). Hospitals and home monitoring are suggested as obvious applications.
• Some highlight positive scenarios only if processing and storage are under local user control (self-hosted servers, offline models, no cloud).

Existing tech and novelty debate

• Commenters note similar capabilities already exist with mmWave / radar modules (especially cheap 60 GHz sensors), and that WiFi-based vital-sign sensing and fall detection have been published for a decade.
• Some dismiss the work as “low-hanging fruit” or incremental; others argue the key advance is getting clinical-level accuracy from commodity WiFi (ESP32, RPi) using CSI, without specialized radar hardware.

Technical limitations and open questions

• Several ask about training/test leakage, multi-person scenarios, performance at elevated heart rates, and empty-room false positives.
• The author clarifies: early splits were leaky but newer work uses subject-wise folds; heart-rate up to ~130 bpm is handled; current model is single-person, multi-person is ongoing.
• Practitioners stress that many impressive sensing papers work only in tightly controlled lab conditions; robustness in messy real environments remains unclear.

Privacy, surveillance, and biometric ID

• Strong concern that this enables ubiquitous, covert biosurveillance via existing routers and devices, especially given many are ISP- or corporately controlled and poorly secured.
• Use cases raised: law enforcement “seeing” through walls (with existing devices), insurers, advertisers, and platforms inferring emotional responses, presence, sexual activity, or identity (via unique cardiac signatures / WiFi CSI “fingerprints”).
• Some call this a “surveillance catastrophe,” especially as WiFi sensing is being standardized (802.11bf) and already shipped in consumer gear.

Safety and RF exposure

• Debate over physiological risk: most frame WiFi as analogous to cameras or ultrasound at typical power levels; others point out RF burns and heating effects at higher powers or close contact, arguing non-ionizing doesn’t mean harmless in all regimes.

Over-monitoring and medicine

• One thread warns that continuous vitals could worsen outcomes via over-diagnosis and over-treatment, citing experiences with continuous fetal/maternal monitoring leading to unnecessary interventions.