The research team is developing innovative, low-cost sensing systems that can achieve privacy-preserving occupancy sensing, movement tracking, and pose detection for individual and group activity monitoring for commercial building management systems to effect significant HVAC energy savings in commercial buildings. The concept is based on a new time-of-flight sensing technology coupled with proprietary sensing, localization and tracking algorithms developed and trained using VR simulation tools and digital twin technologies. The research includes the design, fabrication, implementation and testing of new low-cost, silicon optical bench-based sensor technology. Dual-use applications of the technology under development include movement and/or fall detection in healthcare and eldercare settings.