Wearable Technologies

Transcription

1 Wearable Technologies Introduction and Hardware Architecture WebValley 2015 Bojan Milosevic

2 About Me Bojan Milosevic E3DA - FBK, Trento Micrel Lab, DEI - University of Bologna My research is focused on Body Area Networks and wearable systems for human motion tracking and analysis, with applications for smart environments, natural interaction and healthcare.

3 FBK The E3DA research unit focuses on digital architectures and embedded technologies, targeting hardware and software co-design of energy efficient embedded systems and sensor networks, with applications ranging from Human-Computer Interaction (HCI) to healthcare. HW: System-level design of embedded devices employing state-of-the-art integrated technologies and optimizing the performance/energy-efficiency tradeoff SW: Study and implementation of advanced processing techniques to analyze sensor data and extract information, optimally employing the limited hardware resources of embedded nodes

4 People Elisabetta Farella - Head of Unit Bojan Milosevic - Reserarcher Manuele Rusci, Giovanelli Davide - PhD Students Simone Benatti, Filippo Casamassima PhD UniBO

5 Course Wearable technologies and data analysis Modules: Wearable Technologies (Bojan) Data Analysis for Wearables (Bojan) Python for Data Analysis (Bojan) Practical approach to data collection and analysis (Filippo) + Labs and practical sessions + Exercises and problems to solve

6 Wearable Technologies The terms wearable technology, wearable devices, and wearables all refer to electronic technologies or computers that are incorporated into items of clothing and accessories which can comfortably be worn on the body. can perform many of the same computing tasks as mobile phones and laptop computers can provide sensory and scanning features not typically seen in mobile and laptop devices, such as biofeedback and tracking of physiological function. Blurred definitions and boundaries between: Portable Vs Mobile Vs Wearable

7 Applications Consumer & Gadgets Fitness Fashon Quantified Self Rehabilitation Health

8 System Architecture Sensor nodes(s) form a Body Sensor Network (BSN) of wearable devices. The network has a personal gateway to collect aggregated information, process it and store/forward. It is usually implemented in a smartphone. The smartphone is the interface towards cloud services for data storage and advanced analytics.

9 Wearable Sensor Node Embedded sensing nodes are the basic building block for all applications based on BSNs. The design and the form factor are fundamental: Commercial appeal Comfort and effectiveness of sensing Limited weight and dimensions limit also electronic HW resources Highly optimized design of electronic embedded systems, with integrated HW/SW development.

10 Hardware Architecture Sensor Processing Unit Radio Power Supply Wearable sensor nodes are powered by integrated electronics, which implements sensing, processing and communication functionalities. Main blocks: Sensor Processing Unit Communication (Radio) Power Supply (Battery + management circuitry)

11 Hardware Architecture Sensor Processing Unit Radio Power Supply Integrated Sensors Good news: Low power, not the power bottleneck Miniaturization is rapidly progressing (MEMS) Integration with circuits is possible Issues: Data bandwidth >> information bandwidth Offset, drift A/D conversion: big power premium with high precision/bandwidth EmKay Sisonic Microphone Examples: Gyro, Accelerometer, Proximity, Gas/Bio, Microvision's MEMS scanning mirror for Wearable Displays, Vehicle Displays and Pico Projector Displays

12 Hardware Pipeline Sensor Processing Unit Radio Power Supply Micro-ElectroMechanical (MEMS) Sensors Transduction of a mechanical input in an electric signal Advantages of microsensors: 1. High sensitivity (High Surface area/volume ratio, good S/N ratio; e.g. gas sensors) 2. Local measurements in remote locations (e.g. flow meters in microfluidic systems) 3. Microsystems enable signal processing into a sensor (e.g. to improve S/N ratio) Examples of measurements: Mechanical, Acoustic, Thermal, Optical

13 Hardware Pipeline Sensor Processing Unit Radio Power Supply Micro-ElectroMechanical (MEMS) Sensors Sensing principles (ref. to electrical characteristic changing): Piezoresistive sensing e.g. pressure sensors, microphones, compass Capacitive sensing e.g. accelerometers, microphones Resonant sensing e.g. gyroscopes, DNA resonator

14 Hardware architecture Sensor Processing Unit Radio Power Supply A Microcontroller is a small CPU with many supporting peripherals built into the chip: Self Contained (CPU, Memory, I/O) Application or Task Specific (Not a general-purpose computer) Appropriately scaled for the job Small power consumption Low costs ( $0.50 to $5.00.)

15 Hardware architecture Sensor Processing Unit Radio Power Supply There are 3 «major» families: Arduino (based on Atmel AVR) prototyping boards, DIY projects Texas Instrument s MSP line very low power and limited resources ARM (Cortex line) extended line for wide spectrum of embedded applications

16 Hardware architecture Sensor Processing Unit Radio Power Supply Wireless communication towards host device (e.g. smartphone) Radio TX is the most energy consuming task: very important choice for efficiency and communication capabilities. Physical access 2.4GHz ISM band (e.g. IEEE for radio access) Several competing protocols (Bluetooth, ZigBee, ANT,...) Bluetooth is the only one with high diffusion on standard smartphones, Bluetooth Low Energy (BLE) is designed for wearables

17 Hardware architecture Sensor Processing Unit Radio Power Supply Limited dimensions -> limited battery size -> limited power Power management and energy efficiency is crucial for wearable devices. Careful design of the hardware and software optimization are needed to extend the battery life. Modular design, power gating and DVFS Operation duty cycling and use of sleep/low power states

18 Hardware architecture Sensor Processing Unit Radio Power Supply What if devices could be self-powered? Energy harvesting: collecting energy from sources available in the environment. Solar, motion, wind, heat, all have been exploited to harvest energy from environment. Low for most current wearable applications (1uW Vs 1mW) but very promising trend and research topic.

19 Body Sensor Network Wearable sensor nodes interface with a personal gateway (smartphone) to form a BSN. Network coordination Central data collecting and processing hub Gateway towards online services Data transmission is the most energy consuming task! For optimal operation the needed computing is distributed among nodes and devices of the network. Local (on-device) computing transmission of only useful information Aggregation on smartphone and further processing Remote communication only when necessary

20 Use Case Let s see a research use case for wearable devices: Bojan Milosevic and Elisabetta Farella. Wearable Inertial Sensor for Jump Performance Analysis. In Proceedings of the 2015 workshop on Wearable Systems and Applications (WearSys '15). ACM, New York, NY, USA,

21 Thank You!