University of Oulu

Tjurin P., Niemelä M., Huusko M., Ahola R., Kangas M., Jämsä T. (2018) Classification of physical activities and sedentary behavior using raw data of 3D hip acceleration. In: Eskola H., Väisänen O., Viik J., Hyttinen J. (eds) EMBEC & NBC 2017. EMBEC 2017, NBC 2017. IFMBE Proceedings, vol 65. Springer, Singapore.

Classification of physical activities and sedentary behavior using raw data of 3D hip acceleration

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Author: Tjurin, P.1; Niemelä, M.1; Huusko, M.1;
Organizations: 1Research Unit of Medical Imaging, Physics and Technology (MIPT), University of Oulu, Oulu, Finland
2Polar Electro Oy, Kempele, Finland
3Medical Research Center, University of Oulu and Oulu University Hospital, Oulu, Finland
4Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
Format: article
Version: accepted version
Access: open
Online Access: PDF Full Text (PDF, 0.3 MB)
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Language: English
Published: Springer Nature, 2018
Publish Date: 2020-01-13


The purpose of this study was to develop and validate an algorithm for classifying physical activity (PA) classes and sedentary behavior (SED) from raw acceleration signal measured from hip. Twenty-two adult volunteers completed a pre-defined set of controlled and supervised activities. The activities included nine daily PAs. The participants performed PA trials while wearing a hip-worn 3D accelerometer. Indirect calorimetry was used for measuring energy expenditure. The raw acceleration data were used for training and testing a prediction model in MATLAB environment. The prediction model was built using bagged trees classifier and the most suitable extracted features (mean, maximum, minimum, zero crossing rate, and mean amplitude deviation) were selected using a sequential forward selection method. Leave-one-out cross validation was used for validation. Activities were classified as lying, sitting, light PA (standing, table wiping, floor cleaning, slow walking), moderate PA (fast walking) and vigorous PA (soccer and jogging). The oxygen consumption data were used for estimating the intensity of measured PA. Total accuracy of the prediction model was 96.5%. Mean sensitivity of the model was 95.5% (SD 3.5) and mean specificity 99.1% (SD 0.5). Based on the results PA types can be classified from raw data of the hip-worn 3D accelerometer using supervised machine learning techniques with a high sensitivity and specificity. The developed algorithm has a potential for objective evaluations of PA and SED.

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Series: IFMBE proceedings
ISSN: 1680-0737
ISSN-E: 1433-9277
ISSN-L: 1680-0737
ISBN: 978-981-10-5122-7
ISBN Print: 978-981-10-5121-0
Issue: 65
Pages: 872 - 875
DOI: 10.1007/978-981-10-5122-7_218
Host publication: EMBEC & NBC 2017. Joint Conference of the European Medical and Biological Engineering Conference (EMBEC) and the Nordic-Baltic Conference on Biomedical Engineering and Medical Physics (NBC), Tampere, Finland, June 2017
Host publication editor: Eskola, Hannu
Väisänen, Outi
Viik, Jari
Hyttinen, Jari
Conference: European Medical and Biological Engineering Conference (EMBEC) & Nordic-Baltic Conference on Biomedical Engineering and Medical Physics (NBC)
Type of Publication: A4 Article in conference proceedings
Field of Science: 217 Medical engineering
Funding: The study was supported in part by Polar Electro Oy and the Finnish Funding Agency for Innovation (grant nr 6057/31/2016).
Copyright information: © Springer Nature Singapore Pte Ltd. 2018. This is a post-peer-review, pre-copyedit version of an article published in IFMBE proceedings. The final authenticated version is available online at: