Model-Based Estimation of Ankle Joint Stiffness
Philips Chair for Medical Information Technology, RWTH Aachen University, Pauwelsstrasse 20, 52074 Aachen, Germany
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Sensors 2017, 17(4), 713; https://doi.org/10.3390/s17040713
Received: 16 January 2017 / Revised: 22 March 2017 / Accepted: 23 March 2017 / Published: 29 March 2017
(This article belongs to the Special Issue Wearable Biomedical Sensors)
We address the estimation of biomechanical parameters with wearable measurement technologies. In particular, we focus on the estimation of sagittal plane ankle joint stiffness in dorsiflexion/plantar flexion. For this estimation, a novel nonlinear biomechanical model of the lower leg was formulated that is driven by electromyographic signals. The model incorporates a two-dimensional kinematic description in the sagittal plane for the calculation of muscle lever arms and torques. To reduce estimation errors due to model uncertainties, a filtering algorithm is necessary that employs segmental orientation sensor measurements. Because of the model’s inherent nonlinearities and nonsmooth dynamics, a square-root cubature Kalman filter was developed. The performance of the novel estimation approach was evaluated in silico and in an experimental procedure. The experimental study was conducted with body-worn sensors and a test-bench that was specifically designed to obtain reference angle and torque measurements for a single joint. Results show that the filter is able to reconstruct joint angle positions, velocities and torque, as well as, joint stiffness during experimental test bench movements.
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Keywords:
joint stiffness estimation; body-worn sensors; magnetic, angular rate and gravity sensors; BSN
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MDPI and ACS Style
Misgeld, B.J.E.; Zhang, T.; Lüken, M.J.; Leonhardt, S. Model-Based Estimation of Ankle Joint Stiffness. Sensors 2017, 17, 713. https://doi.org/10.3390/s17040713
AMA Style
Misgeld BJE, Zhang T, Lüken MJ, Leonhardt S. Model-Based Estimation of Ankle Joint Stiffness. Sensors. 2017; 17(4):713. https://doi.org/10.3390/s17040713
Chicago/Turabian StyleMisgeld, Berno J.E.; Zhang, Tony; Lüken, Markus J.; Leonhardt, Steffen. 2017. "Model-Based Estimation of Ankle Joint Stiffness" Sensors 17, no. 4: 713. https://doi.org/10.3390/s17040713
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