Signal scavenging for passive monitoring in eldercare technology

Signal scavenging is analogous to energy scavenging: seemingly ubiquitous energy in the environs provides the signal for usage as a personnel sensor. Such energy can be used to detect motion, and most importantly falls. Stray signals can be detected in aluminum foil as voltage differences between touched foil (say by hand) compared to that untouched. Spectrum analysis shows the stray electromagnetic noise signal consists substantially of 60 Hz and its harmonics. Also the signal intensity for both touched and untouched monotonically increases with foil area. While personnel monitors find utility in many areas including security, personnel control and activity detection, we believe these putative sensors to be useful in inobtrusive monitoring of elders to provide them with increased independence at a critical time in their lives.