Sensing and Effecting Environment with Extremity Computing Devices

This paper presents the “extremity” approach to creating user-interface experiences. We describe a class of dataacquisition systems called “extremity-computing devices” and their broad implications to user-interface design scenarios. These devices are used to interface sensors and effectors in wearable-computer applications. Instead of wearing a complete computer, outfitted with interface, storage, and processing components, a user needs only to wear sensors attached to a small microcontroller-based device with rudimentary user interface, local storage, and off-body transfer. Users access data externally, on a device of their choice: hand-held, laptop, or desktop computer, cell phone, etc. We have used extremity devices to gather physiological and motion data, surrounding temperature and lighting conditions, proximity, and the identity of people and objects nearby. We have utilized data gathered by these devices in applications in the areas of education, research, healthcare, and entertainment. The value of the extremity-computing approach for rapid design is shown, as are robust demonstrations of scenarios, including: medical applications for a collaborative exercise game; stress monitoring and feedback; biofeedback training tools; biofeedback controlling toys and game software, teaching people to swing a baseball bat correctly; and helping understand principles of lie detection.