Print Email Facebook Twitter In-vitro validation of inertial-sensor-to-bone alignment Title In-vitro validation of inertial-sensor-to-bone alignment Author Weygers, Ive (Katholieke Universiteit Leuven) Kok, M. (TU Delft Team Manon Kok) Seel, Thomas (Friedrich-Alexander-Universität Erlangen-Nürnberg) Shah, Darshan (Katholieke Universiteit Leuven) Taylan, Orçun (Katholieke Universiteit Leuven) Scheys, Lennart (University Hospital Leuven; Katholieke Universiteit Leuven) Hallez, Hans (Katholieke Universiteit Leuven) Claeys, Kurt (Katholieke Universiteit Leuven) Date 2021 Abstract A major shortcoming in kinematic estimation using skin-attached inertial sensors is the alignment of sensor-embedded and segment-embedded coordinate systems. Only a correct alignment results in clinically relevant kinematics. Model-based inertial-sensor-to-bone alignment methods relate inertial sensor measurements with a model of the joint. Therefore, they do not rely on properly executed calibration movements or a correct sensor placement. However, it is unknown how accurate such model-based methods align the sensor axes and the underlying segment-embedded axes, as defined by clinical definitions. Also, validation of the alignment models is challenging, since an optical motion capture ground truth can be prone to disturbances from soft tissue movement, orientation estimation and manual palpation errors. We present an anatomical tibiofemoral ground truth on an unloaded cadaveric measurement set-up that intrinsically overcomes these disturbances. Additionally, we validate existing model-based alignment strategies. Modeling the degrees of freedom leads to the identification of rotation axes. However, there is no reason why these axes would align with the segment-embedded axes. Relative inertial-sensor orientation information and rich arbitrary movements showed to aid in identifying the underlying joint axes. The first dominant sagittal rotation axis aligned sufficiently well with the underlying segment-embedded reference. The estimated axes that relate to secondary kinematics tend to deviate from the underlying segment-embedded axes as much as their expected range of motion around the axes. In order to interpret the secondary kinematics, the alignment model should more closely match the biomechanics of the joint. Subject Human movement analysisIMUJoint kinematicsLower limbSensor-to-segment alignment To reference this document use: http://resolver.tudelft.nl/uuid:52baceef-93f6-4e64-b11b-164529eaa05c DOI https://doi.org/10.1016/j.jbiomech.2021.110781 Embargo date 2022-04-02 ISSN 0021-9290 Source Journal of Biomechanics, 128 Bibliographical note Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Part of collection Institutional Repository Document type journal article Rights © 2021 Ive Weygers, M. Kok, Thomas Seel, Darshan Shah, Orçun Taylan, Lennart Scheys, Hans Hallez, Kurt Claeys Files PDF 1_s2.0_S0021929021005455_main_1.pdf 1.74 MB Close viewer /islandora/object/uuid:52baceef-93f6-4e64-b11b-164529eaa05c/datastream/OBJ/view