The adaptive drop foot stimulator – Multivariable learning control of foot pitch and roll motion in paretic gait
Seel T, Werner C, Schauer T (2016)
Publication Type: Journal article
Publication year: 2016
Journal
Book Volume: 38
Pages Range: 1205-1213
Journal Issue: 11
DOI: 10.1016/j.medengphy.2016.06.009
Abstract
Many stroke patients suffer from the drop foot syndrome, which is characterized by a limited ability to lift (the lateral and/or medial edge of) the foot and leads to a pathological gait. In this contribution, we consider the treatment of this syndrome via functional electrical stimulation (FES) of the peroneal nerve during the swing phase of the paretic foot. A novel three-electrodes setup allows us to manipulate the recruitment of m. tibialis anterior and m. fibularis longus via two independent FES channels without violating the zero-net-current requirement of FES. We characterize the domain of admissible stimulation intensities that results from the nonlinearities in patients’ stimulation intensity tolerance. To compensate most of the cross-couplings between the FES intensities and the foot motion, we apply a nonlinear controller output mapping. Gait phase transitions as well as foot pitch and roll angles are assessed in realtime by means of an Inertial Measurement Unit (IMU). A decentralized Iterative Learning Control (ILC) scheme is used to adjust the stimulation to the current needs of the individual patient. We evaluate the effectiveness of this approach in experimental trials with drop foot patients walking on a treadmill and on level ground. Starting from conventional stimulation parameters, the controller automatically determines individual stimulation parameters and thus achieves physiological foot pitch and roll angle trajectories within at most two strides.
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Germany (DE)How to cite
APA:
Seel, T., Werner, C., & Schauer, T. (2016). The adaptive drop foot stimulator – Multivariable learning control of foot pitch and roll motion in paretic gait. Medical Engineering & Physics, 38(11), 1205-1213. https://doi.org/10.1016/j.medengphy.2016.06.009
MLA:
Seel, Thomas, Cordula Werner, and Thomas Schauer. "The adaptive drop foot stimulator – Multivariable learning control of foot pitch and roll motion in paretic gait." Medical Engineering & Physics 38.11 (2016): 1205-1213.
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