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Wireless Communications and Sensing in e-Health

Robert J. Piechocki Communications Systems and NetworksSmart Internet Lab

02/12/15 ‘Wireless in the built environment' Radio Technology SIG event

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Introducing SPHEREA Sensor Platform for Healthcare in a Residential EnvironmentDirector: Prof Ian Craddock• £12M over 5 years (plus £3M from industry and the Universities=£15M)• Led by University of Bristol.• Probably EPSRC’s largest current eHealth IoT research project• A team of over ~100 researchersIn collaboration with Southampton University (Health Sciences), Southampton University (Electrical Engineering), Reading University (Cybernetics), the Elizabeth Blackwell Health Research Institute, Bristol Vision Institute, Department of Experimental Psychology, School of Social and Community Medicine, School of Oral and Dental Sciences, the Centre for Medical Ethics, the Centre for Public Engagement, School of Clinical Sciences, Communications Systems & Networks Group, Intelligent Systems Group, Bristol Heart Institute, Interaction & Graphics Group, Bristol Health Partners, ALSPAC (Children of 90s), Bristol City Council, Knowle West Media Centre, Bristol NIHR Biomedical Research Unit in Nutrition, Diet & Lifestyle, Bristol NIHR Biomedical Research Unit for Cardiovascular Disease, IBM and Toshiba.

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activity monitoring via accelerometers 

(&others)

water consumption, electrical consumption

temperature, light levels, humidity, air‐

quality

base‐station, +social media, +encryption

analysis, pattern extraction, feature extraction

data display

VideoEmotion, gait, activity, 

interaction

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Activity Recognition

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Online quality assessment of humanmovement from skeleton data*

Recovered

Injured

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Wearable IoTs (SPW-1)• Features:

• Dual ultra low power accelerometer• High energy efficiency (battery lifetime up to 1 year)• Improved wireless performance (2dB better than kit ‐ DK)• Energy‐harvesting ready

Ultra low‐power long‐term wireless connectivity

Dual polarization receiver

Energy consumption for SPW-1

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What IoT radio should you choose? IEEE 802.15.4 or BLE? 

Energy consumption for the transmission of a successful byte (accountingfor potential retransmissions) for various transmission power levels,considering PDUs of 39 bytes.

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• Novel algorithms developed• No extra cost for the wearable

Application‐layer coding

• Any 2 out of 3 correct packets are sufficient to recover both A & B

CRC Error Correction

Interference, coexistence and networking

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Interference mitigation: network-wide error correction

• Packet error rate (PER) is reduced by 80%• Traffic to the central hub is reduced by 57%• Computational load is distributed over all devices

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Ultra Low Power Voltage Detector

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RF Rectenna Design

RF Energy harvesting / transfer

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Low power intermittent RF signal: infrequent transmissions with very low power Interference:multiple concurrent 2.4 GHz radios: WiFi, Bluetooth, 15.4, ZigBee Limited data: Only RSSI is readily available; Doppler, timing, angular information

requires additional hardware

RF Indoor localisation and passive sensing

Indoor propagation characteristics examples Classification example

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Passive Wireless Sensing with opportunistic Energy Harvesting signal reuse

Stairs climbing activity recognition

• Complement to more traditional techniques: Video & PIR• Capability: activity recognition (walking, stairs climbing, seating

etc) vital signs (respiration)

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Extracting Meaning from Data

• Multi‐resident homes• Uncertainty management for multi‐sensor fusion.• Labelled data is expensive.• Unsupervised learning of suitable features.

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Conclusions

Key challenges:

• Reliable low power wireless connectivity• Battery free IoT devices• Security solutions for highly constrained devices• Making sense out of the data• User‐research, in the wild

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ian.craddock@bristol.ac.uk, r.j.piechocki@bristol.ac.uk (wireless & sensing)bernard.stark@bristol.ac.uk (energy harvesting), m.mirmehdi@bristol.ac.uk (video),peter.flach@bristol.ac.uk (data mining), g.oikonomou@bristol.ac.uk (networking)

Contacts:

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