Optimising and validating an electromagnetic tracker in a human performance laboratory

Andrew James Murphy, A.M.J. Bull, A.H. McGregor

    Research output: Contribution to journalArticle

    4 Citations (Scopus)

    Abstract

    Measurement errors have previously been observed using electromagnetic motion trackers in applied laboratories. The aims of this study were to optimize the layout of a human performance laboratory for assessing ergometer rowing technique, and to assess the precision and repeatability of measured rotations and trajectories using the Flock of Birds electromagnetic tracker. Four experiments investigated system performance over a large experimental volume: optimization of laboratory space, repeatability of laboratory layout, precision of measured rotations, and repeatability of measured displacements. Measurement accuracy was influenced by varying the global position of the system transmitter; results suggested a correlation with increasing distance between the electromagnetic source and equivalent sensors. Bringing the transmitter or sensors into closer proximity of metallic items may be another source of measurement error. An optimal location for the transmitter was identified, into which the transmitter was repositioned with good repeatability. Measurements were not negativelyaffected by the presence of a rowing ergometer in the experimental volume. Induced sensor rotations were reconstructed with high precision, and the system calculated small changes in sensor displacement with good repeatability. The system is a suitable technology for measuring the trajectory and rotation of moving body segments in applied human movement laboratories.
    Original languageEnglish
    Pages (from-to)343-351
    Number of pages9
    JournalProceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
    Volume225
    Issue number4
    DOIs
    Publication statusPublished - Apr 2011

    Fingerprint

    Electromagnetic Phenomena
    Transmitters
    Exercise equipment
    Sensors
    Measurement errors
    Trajectories
    Birds
    Research Design
    Technology
    Experiments

    Keywords

    • motion analysis
    • optimization
    • accuracy
    • precision
    • rowing

    Cite this

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    abstract = "Measurement errors have previously been observed using electromagnetic motion trackers in applied laboratories. The aims of this study were to optimize the layout of a human performance laboratory for assessing ergometer rowing technique, and to assess the precision and repeatability of measured rotations and trajectories using the Flock of Birds electromagnetic tracker. Four experiments investigated system performance over a large experimental volume: optimization of laboratory space, repeatability of laboratory layout, precision of measured rotations, and repeatability of measured displacements. Measurement accuracy was influenced by varying the global position of the system transmitter; results suggested a correlation with increasing distance between the electromagnetic source and equivalent sensors. Bringing the transmitter or sensors into closer proximity of metallic items may be another source of measurement error. An optimal location for the transmitter was identified, into which the transmitter was repositioned with good repeatability. Measurements were not negativelyaffected by the presence of a rowing ergometer in the experimental volume. Induced sensor rotations were reconstructed with high precision, and the system calculated small changes in sensor displacement with good repeatability. The system is a suitable technology for measuring the trajectory and rotation of moving body segments in applied human movement laboratories.",
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    Optimising and validating an electromagnetic tracker in a human performance laboratory. / Murphy, Andrew James; Bull, A.M.J.; McGregor, A.H.

    In: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine , Vol. 225, No. 4, 04.2011, p. 343-351.

    Research output: Contribution to journalArticle

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