Speaker: Joss LangfordPresentation: Event based classification of human behaviourDate: Tuesday 16th September 2014Session: (4) Business Applications of RTime: 1330 1500 hrs‐Place: Tower Suite 3

Event based classification of human behaviour:strategic commercial use of open source tools

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GENEActiv

• Activinsights specialises in the science of behavioural measurement with the aim of benefiting people’s overall health

• GENEActiv wrist-worn accelerometers are the device of choice for studies at many of the world’s leading universities, hospitals and professional sports bodies

• The original open raw data accelerometer – giving uncompressed data in SI units

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Strategic – Commercial - Open

Background:• GENEActiv is a general purpose instrument – specialisation comes at the

software & analysis stage• Our customers often produce large data sets – up to 10,000 subjects at

0.5Gb each• GENEActiv is largely used in research (academic & commercial)

Open source tools allow us to:• Support a huge range of applications without significant business risk and

overhead• Collaborate with academics and other commercial partners• Provide referenced open releases of tools via CRAN

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Impact

Many studies and most large national studies now use raw data in SI units – often GENEActiv & GENEAread

Examples:• General behaviour• Sports • Sleep• Visualisation• Algorithms

American Journal of Epidemiology

Association Between Questionnaire- and Accelerometer-Assessed Physical Activity: The

Role of Sociodemographic Factors

CRAN: GGIR

Sleep Journal

Sleep Estimates Using Microelectromechanical Systems

(MEMS)

CRAN: GENEAsphere

Journal of Applied Physiology

Auto-calibration of accelerometer data for free-living physical activity assessment using local gravity and temperature: an evaluation

on four continents

CRAN: GGIR

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Event-based classification

• While we have been successful moving the industry to SI units – we still have work to do in the area of fixed epoch summaries

• Large time-series data sets are not intuitive for human handling

• Nearly all our customers use fixed epoch summaries – but variable length event-based summaries have many advantages

• Is it a classification or a changepoint problem?

• There is a natural granularity of everyday life

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Coelition

• Coelition is an open standards organisation that is developing a standard to help classify everyday living

• The Classification of Everyday Living (COEL) is a hierarchical taxonomy with 32 top level clusters - currently coding over 7,000 behavioural events

• The hierarchical structure allows information from different sources to be recorded in the same framework

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Raw data view of a morning

Accelerometer

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Event-based view

phone screen on

location 1 location 2 location 3

Simple phone app

sleep

child woke during night got up

drove tostation

train to London

boughtcoffeeDiary

Accelerometer

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Future challenges

• Using ‘GENEAclassify’ as a starting point, build our abilities to intelligently analyse raw data accelerometry

• Develop better deployment toolse.g. file handling, parallelisation and interfacing

• Develop new tools for the analysis of event-based datae.g. sequence analysis

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Acknowledgements & information

Zhou Fang, Biomathematics & Statistics ScotlandSéverine Sabia, University College LondonVincent van Hees, Newcastle UniversityJohn Bardon, University of ReginaAlex Rowlands, University of South AustraliaMatt Reed, Coelition

joss@activinsights.co.uk