Functionality-power-packaging considerations in context aware wearable systems

Abstract

Wearable computing places tighter constraints on architecture design than traditional mobile computing. The architecture is described in terms of miniaturization, power-awareness, global low-power design and suitability for an application. In this article we present a new methodology based on three different system properties. Functionality, power and electronic Packaging metrics are proposed and evaluated to study different trade offs. We analyze the trade offs in different context recognition scenarios. The proof of concept case study is analyzed by studying (a) interaction with household appliances by a wrist worn device (acceleration, light sensors) (b) studying walking behavior with acceleration sensors, (c) computational task and (d) gesture recognition in a wood-workshop using the combination of accelerometer and microphone sensors. After analyzing the case study, we highlight the size aspect by electronic packaging for a given functionality and present the miniaturization trends for 'autonomous sensor button'.Keywords Wearable computing Á Context recognition Á Gesture Á Electronic packaging Á Functionality Á Miniaturization Context aware wearable systemsWearable computing as defined by [1, 2] envisions personal, mobile computing systems that are always on, useful in all situations and most of all, easy to use. Thus whereas a conventional mobile device would only be used for an occasional schedule check or address lookup, a wearable device would constantly provide the user with useful information such as nearby shops and special offers, transport delays, or health and lifestyle-related reminders (taking medicine, diet etc). Such systems are particularly important in professional applications such as emergency response units, manufacturing and maintenance. Thus a wearable system might constantly provide a fireman with hints and warning about hazards related to his environment, his physiological state and his current actions.A key component of the wearable computing vision is the ability of the system to model and recognize user activity and the situation around him. This so called context awareness [3] allows the system to proactively provide the user with the right information at the right time, reduces the complexity of the user interface, and allows new modes of information recording. One of the most popular approaches to context awareness in a mobile environment is based on simple on-body sensors. Thus an accelerometer, light sensor and a microphone placed on the wrist could be used to track interaction with household appliances [4] or the use of tools [5]. In a similar way an accelerometer and/or gyroscope on the upper leg can differentiate between level walking, going upstairs, going downstairs and running.

Prediction of Harvestable Energy for Self-Powered Wearable Healthcare Devices: Filling a Gap

“…The storage process has two-folds: nonvolatile memory to store the application-related data, and an active memory which temporarily stores the sensed data and the internal clock. It is a good practice to deploy low-power microcontrollers in the processing and storage subsystem of the wireless sensor nodes due to their small size, low-power consumption, low-cost, and compact construction compared to the field-programmable gate arrays (FPGAs) [22]. The radio subsystem uses low-power transceivers, and radio frequency antennas to connect the node to the WSN gateway in case of point-to-point communication, or to the other WSN nodes creating a mesh.…”

Healthcare Sensing and Monitoring

“…When designing such systems, it should be taken into account the so called "wearability", which means weight, form, heat generation, flexibility and other properties. In technical point of view, the main considerations include the power consumption and overall system size in order to achieve good "wearability" [62].…”

A Position Detection Method of Devices on Conductive Clothes by Controlling Led Blinking

“…As researches on systems using conductive fabrics, Networked Vest 5 uses conductive fabric on both sides of the wear, and the devices attached to the vest have DC-PLC (Power Line Communication) modems that provide DC power from a single power supply as well as modulated analog signal communication. Electronic Textiles 18 uses a conductive thread with an insulator coating for horizontal and vertical directions as well as insulator thread. Communication-Wear 21 is a clothing concept that augments a mobile phone by enabling expressive messages to be remotely exchanged between people.…”