Wearable sensing devices for human-machine interaction systems

Two projects involving wearable sensing devices with antennas are summarized. The first project senses physiological signals; namely, photoplethysmograph (PPG), galvanic skin response (GSR), and skin temperature (SKT), in a design that is low cost, low power, and embedded in a non-intrusive wristband form factor. These wearable sensors are capable of physiological monitoring, which is important when detecting implicit communication cues related to emotions and affective expressions such that affective computing is possible [1]. The device transmits data wirelessly to a PC using Bluetooth Low Energy (BLE) technology. A related computer interaction has been developed to teach words to students, while monitoring their physiological signals to classify engagement. The second project aims to provide occupant-specific energy feedback in real-time. To do so, it is necessary to gather information about how each occupant is using energy (i.e., how much electricity they use on a daily basis). Therefore, a sensor was designed with the capabilities of detecting energy-related events, confirming the energy-related events using a proximity sensing technique, and being small enough to be worn or carried around during day-to-day activities. The printed circuit board (PCB) designs of both projects are summarized.