A Review of Low-Cost Bio-Acoustic Human Presence Detection

In smart buildings, energy-efficient HVAC/light control, security and health-aware environments, human occupancy information is critical to these systems. Current methods of sensing human occupancy, such as Passive Infrared (PIR), Carbon Dioxide (CO₂), Radio Frequency (RF) and vision-based systems typically have limitations regarding privacy, visibility restrictions, and limited accuracy when an individual is stationary and expensive and complicated. In this paper, proposes and describe an alternate paradigm for detecting the occupancy of humans by utilizing and analysing low-frequency acoustic signals produced from natural breathing of an individual, micro-movement of the chest and/or body. The current state of the art in acoustic/non-intrusive presence sensing; the physiological properties and characteristics of signals related to bio-acoustics and the use of low-cost MEMS microphones and embedded microcontrollers to provide real-time human occupancy detection applications. Bio-acoustic sensing with traditional methods on several factors as privacy, cost, ability to detect a stationary person, environmental sensitivity. The paper concludes with identifying areas for future research which involve sensor integration, adaptive signal processing, and embedded real-time implementation. The paper concludes by supporting bio-acoustic detection as a feasible, low-cost, privacy-oriented method to detect the presence of people within smart buildings and homes.