Classification of accelerometer wear and non-wear events in seconds for monitoring free-living physical activity. Issue 5 (11th May 2015)
- Record Type:
- Journal Article
- Title:
- Classification of accelerometer wear and non-wear events in seconds for monitoring free-living physical activity. Issue 5 (11th May 2015)
- Main Title:
- Classification of accelerometer wear and non-wear events in seconds for monitoring free-living physical activity
- Authors:
- Zhou, Shang-Ming
Hill, Rebecca A
Morgan, Kelly
Stratton, Gareth
Gravenor, Mike B
Bijlsma, Gunnar
Brophy, Sinead - Abstract:
- Abstract : Objective: To classify wear and non-wear time of accelerometer data for accurately quantifying physical activity in public health or population level research. Design: A bi-moving-window-based approach was used to combine acceleration and skin temperature data to identify wear and non-wear time events in triaxial accelerometer data that monitor physical activity. Setting: Local residents in Swansea, Wales, UK. Participants: 50 participants aged under 16 years (n=23) and over 17 years (n=27) were recruited in two phases: phase 1: design of the wear/non-wear algorithm (n=20) and phase 2: validation of the algorithm (n=30). Methods: Participants wore a triaxial accelerometer (GeneActiv) against the skin surface on the wrist (adults) or ankle (children). Participants kept a diary to record the timings of wear and non-wear and were asked to ensure that events of wear/non-wear last for a minimum of 15 min. Results: The overall sensitivity of the proposed method was 0.94 (95% CI 0.90 to 0.98) and specificity 0.91 (95% CI 0.88 to 0.94). It performed equally well for children compared with adults, and females compared with males. Using surface skin temperature data in combination with acceleration data significantly improved the classification of wear/non-wear time when compared with methods that used acceleration data only (p<0.01). Conclusions: Using either accelerometer seismic information or temperature information alone is prone to considerable error. Combining bothAbstract : Objective: To classify wear and non-wear time of accelerometer data for accurately quantifying physical activity in public health or population level research. Design: A bi-moving-window-based approach was used to combine acceleration and skin temperature data to identify wear and non-wear time events in triaxial accelerometer data that monitor physical activity. Setting: Local residents in Swansea, Wales, UK. Participants: 50 participants aged under 16 years (n=23) and over 17 years (n=27) were recruited in two phases: phase 1: design of the wear/non-wear algorithm (n=20) and phase 2: validation of the algorithm (n=30). Methods: Participants wore a triaxial accelerometer (GeneActiv) against the skin surface on the wrist (adults) or ankle (children). Participants kept a diary to record the timings of wear and non-wear and were asked to ensure that events of wear/non-wear last for a minimum of 15 min. Results: The overall sensitivity of the proposed method was 0.94 (95% CI 0.90 to 0.98) and specificity 0.91 (95% CI 0.88 to 0.94). It performed equally well for children compared with adults, and females compared with males. Using surface skin temperature data in combination with acceleration data significantly improved the classification of wear/non-wear time when compared with methods that used acceleration data only (p<0.01). Conclusions: Using either accelerometer seismic information or temperature information alone is prone to considerable error. Combining both sources of data can give accurate estimates of non-wear periods thus giving better classification of sedentary behaviour. This method can be used in population studies of physical activity in free-living environments. … (more)
- Is Part Of:
- BMJ open. Volume 5:Issue 5(2015)
- Journal:
- BMJ open
- Issue:
- Volume 5:Issue 5(2015)
- Issue Display:
- Volume 5, Issue 5 (2015)
- Year:
- 2015
- Volume:
- 5
- Issue:
- 5
- Issue Sort Value:
- 2015-0005-0005-0000
- Page Start:
- Page End:
- Publication Date:
- 2015-05-11
- Subjects:
- physical activity -- sedentary behaviour -- non-wear -- accelerometer -- PUBLIC HEALTH -- classification
Medicine -- Research -- Periodicals
610.72 - Journal URLs:
- http://www.bmj.com/archive ↗
http://bmjopen.bmj.com/ ↗ - DOI:
- 10.1136/bmjopen-2014-007447 ↗
- Languages:
- English
- ISSNs:
- 2044-6055
- Deposit Type:
- Legaldeposit
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- Available online (eLD content is only available in our Reading Rooms) ↗
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