June 23, 2026 – Stanford, CA – Privacy-Preserving Safety Monitoring
Researchers at Stanford University have published a paper demonstrating that PIR sensor arrays can effectively monitor social distancing in workplace settings without using cameras. The system preserves employee privacy while providing real-time alerts when distancing protocols are violated.
The Technology
The system uses a ceiling-mounted array of 16 PIR sensors covering a 10m × 10m area. Machine learning algorithms process the sensor data to:
- Detect the number of people in the space
- Estimate distances between individuals
- Track movement patterns over time
- Alert when distancing thresholds are exceeded
Unlike cameras, the PIR array does not capture identifiable images, addressing privacy concerns that have limited adoption of camera-based systems.
Performance Results
In testing across office, retail, and healthcare settings:
- Occupancy counting accuracy: 96%
- Distance estimation accuracy: ±0.5m
- Privacy compliance: Full (no images captured)
- False alert rate: 3%
Applications
- Open office plans
- Hospital waiting rooms
- Retail stores
- Conference rooms
- Healthcare facilities
The research was funded by the National Science Foundation and published in the Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies.