Abstract: A method and a low-cost, robust and simple system for remote sensing and analyzing spectral properties of targets as a means to detect and identify them is introduced. The system can be highly portable but is usable in fixed locations or combination thereof. An aspect of the method and system includes the capability to distribute, modulate, aperture and spectrally analyze radiation emitted or absorbed by a volumetric target chemical species (solid, liquid or gas) or a target surface. Radiation is first collected by a single light gathering device, such as a lens, telescope, or mirror, and then distributed to multiple detectors through spectrally discriminating components and if desired through apertures to achieve this desired detection and identification.

Abstract: An apparatus to establish bi-directional digital communication over a power line network includes a signal launching circuit to impose a digital communication signal onto a power signal carried by a power line network and thereby form a digital communication power signal at a first point in the power line network. The signal launching circuit is configured to position a pulse of the digital communication signal at any phase location of each half cycle of the power signal. A receiver reads the digital communication power signal at a second point in the power line network. A signal processor is connected to the receiver to recover the digital communication signal from the digital communication power signal.

Abstract: A monitoring system uses infrared photoplethysmography to monitor the pulse of a person wearing a wrist unit, and the wrist unit sends RF signals which describe his heart condition to a base unit. If the wrist unit detects a cardiac arrest or if the wearer manually signals an emergency, both the wrist and the base units sound local alarms. The base unit also telephones others outside of the user's home to alert them to the emergency. The wrist unit is designed to be fail-safe and to prevent false alarms. When the wrist unit fails to detect a pulse, it makes several further attempts to detect a pulse before signalling a cardiac arrest emergency. A prioritization and output activation circuit activates wrist unit outputs, including audio signals, an RF signal transmitter, and a display, according to a predetermined priority when more than one condition requiring a response exists.