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Wireless Health 2014 Conference Technical Session 6 featuring speaker James Heathers.
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WLSACONVERGENCE SUMMIT
“SMARTPHONE PLATFORM SURVEY-SCALE HEART RATE COLLECTION – A PERFORMANCE EVALUATION IN ETHIOPIA”
JAMES A. J. HEATHERSPH.D., UNIVERSITY OF SYDNEY
Ph.D., University of SydneyJAMES A. J. HEATHERS
“Smartphone Platform Survey-Scale Heart Rate Collection – a Performance Evaluation in Ethiopia”
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WHAT IS HRV?
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PROBLEMS WITH HRV
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PROBLEMS WITH HRV
HRV NOW:
• POORLY CONTROLLED• SMALL SAMPLE SIZE
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TWO BETTER MODELS:
1. CAREFUL EXPERIMENTAL CONTROL
2. MASSIVELY INCREASED SAMPLE SIZE
PROBLEMS WITH HRV
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TWO BETTER MODELS:
1. CAREFUL EXPERIMENTAL CONTROL
2. MASSIVELY INCREASED SAMPLE SIZE
PROBLEMS WITH HRV
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IDEAL MASS COLLECTION:
• Accurate• Robust• Cheap• Components
• Off shelf• Swappable
THE NEW SYSTEM
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THE NEW SYSTEM
• iOS device (iPod, iPad etc.)
• Hardware switching box
• Optical finger sensor (PPG)
• www.myithlete.com
A/DBandpassfilter
d/dtPeak
detectTime
stamp
Sensor
iPod/iPhone
Logfile
HRV
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HEATHERS et al (2012); HEATHERS (2014b)
Is pulse rate accurate enough to measure HRV?
Yes.
PROBLEMS WITH HRV
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HEATHERS (2013);HEATHERS (2014a)
Is this system accurate enough to support HRV?
Yes.
PROBLEMS WITH HRV
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“The International Food Policy Research Institute (IFPRI) seeks sustainable solutions
for ending hunger and poverty.”
THE IFPRI
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HRV in Development Economics
• HRV as stress correlate (in realistic sample)
• HRV as predictor of program success or covariate
• HRV as control against response bias
THE IFPRI
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TWO PURPOSES
1. FIELD TRIAL, IN CONTEXT
2. PROPERTIES OF MASSIVELY INCREASING SAMPLE SIZE
EXPERIMENT
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PARAMETERS• 17 enumerators (locals, no research experience)
EXPERIMENT
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PARAMETERS• 20 iPod Touch + extra sensors
EXPERIMENT
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PARAMETERS• 6 supervisors
EXPERIMENT
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PARAMETERS• Animated indicators on phone
EXPERIMENT
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SAMPLE
• N=679• n=1205 recordings• 91.7% usability (93.3% in new sample)
RESULTS
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OUTCOMES
• Age/gender relationships as expected
• Relationship with alcohol consumption (analogue of self-control?)
RESULTS
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ONGOING:
• Correlate of food-aid program (n=1142), still analysing
• Largest HRV study ever… (presently n=3408)
RESULTS
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PAPER
WLSACONVERGENCE SUMMIT
www.wirelesshealth2014.org