Speaker:
Presentation:
Date:
Session:
Time:
Place:
Joss Langford
Event based classification of human behaviour
Tuesday 16th September 2014
(4) Business Applications of R
1330 ‐ 1500 hrs
Tower Suite 3
Event based classification of human behaviour:
strategic commercial use of open source tools
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
© Activinsights Limited 2014
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
© Activinsights Limited 2014
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
AssociationSleep
Between
Questionnaire- and
Journal
Accelerometer-Assessed Physical Activity:
The Role
of Estimates
Sociodemographic
Factors
Sleep
Using
Journal
of Applied
Physiology
Microelectromechanical Systems
(MEMS)
Auto-calibration of accelerometer
data CRAN:
for GGIR
free-living physical activity assessment using
local gravity and temperature: an evaluation
on four continents
CRAN: GENEAsphere
CRAN: GGIR
© Activinsights Limited 2014
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
© Activinsights Limited 2014
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
© Activinsights Limited 2014
Raw data view of a morning
Accelerometer
© Activinsights Limited 2014
Event-based view
Accelerometer
Diary
child woke during night
got up
sleep
Simple phone app
bought
coffee
drove to
station
train to London
phone screen on
location 1
location 2
location 3
© Activinsights Limited 2014
Future challenges
•
Using ‘GENEAclassify’ as a starting point, build our abilities to intelligently
analyse raw data accelerometry
•
Develop better deployment tools
e.g. file handling, parallelisation and interfacing
•
Develop new tools for the analysis of event-based data
e.g. sequence analysis
© Activinsights Limited 2014
Acknowledgements & information
Zhou Fang, Biomathematics & Statistics Scotland
Séverine Sabia, University College London
Vincent van Hees, Newcastle University
John Bardon, University of Regina
Alex Rowlands, University of South Australia
Matt Reed, Coelition
joss@activinsights.co.uk
© Activinsights Limited 2014