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
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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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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