A decentralized adaptive fuzzy robust strategy for control of upright standing posture in paraplegia using functional electrical stimulation

Kobravi, Hamid Reza; Erfanian, Abbas

doi:10.1016/j.medengphy.2011.06.013

Cited by 31 publications

(22 citation statements)

References 27 publications

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“…Feedback control has been previously used for control of hand grasp (Lujan and Crago, 2009), standing posture (Fraix et al, 2006; Rosin et al, 2011), and locomotion (Roham et al, 2007; Takmakov et al, 2010; Fitzgerald, 2014) in SCI individuals. Simple feedback control can be improved by using adaptive systems (Karniel and Inbar, 2000; Kobravi and Erfanian, 2012). Adaptive algorithms modify controller behavior in response to changes in the system and the environment (Chizek et al, 1988; Narendra, 1990; Narendra and Parthasarathy, 1990; Teixeira et al, 1991; Kostov et al, 1995; Davoodi and Andrews, 1998, 1999; Jonić et al, 1999; Abbas and Riener, 2001).…”

Section: Optimal Control Paradigmsmentioning

confidence: 99%

Restoration of motor function following spinal cord injury via optimal control of intraspinal microstimulation: toward a next generation closed-loop neural prosthesis

et al. 2014

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Movement is planned and coordinated by the brain and carried out by contracting muscles acting on specific joints. Motor commands initiated in the brain travel through descending pathways in the spinal cord to effector motor neurons before reaching target muscles. Damage to these pathways by spinal cord injury (SCI) can result in paralysis below the injury level. However, the planning and coordination centers of the brain, as well as peripheral nerves and the muscles that they act upon, remain functional. Neuroprosthetic devices can restore motor function following SCI by direct electrical stimulation of the neuromuscular system. Unfortunately, conventional neuroprosthetic techniques are limited by a myriad of factors that include, but are not limited to, a lack of characterization of non-linear input/output system dynamics, mechanical coupling, limited number of degrees of freedom, high power consumption, large device size, and rapid onset of muscle fatigue. Wireless multi-channel closed-loop neuroprostheses that integrate command signals from the brain with sensor-based feedback from the environment and the system's state offer the possibility of increasing device performance, ultimately improving quality of life for people with SCI. In this manuscript, we review neuroprosthetic technology for improving functional restoration following SCI and describe brain-machine interfaces suitable for control of neuroprosthetic systems with multiple degrees of freedom. Additionally, we discuss novel stimulation paradigms that can improve synergy with higher planning centers and improve fatigue-resistant activation of paralyzed muscles. In the near future, integration of these technologies will provide SCI survivors with versatile closed-loop neuroprosthetic systems for restoring function to paralyzed muscles.

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Section: Optimal Control Paradigmsmentioning

confidence: 99%

Restoration of motor function following spinal cord injury via optimal control of intraspinal microstimulation: toward a next generation closed-loop neural prosthesis

et al. 2014

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“…A number of FES closed-loop control strategies have been investigated, predominantly focusing on plantarflexion/dorsiflexion control of the ankle joints during stance. These have included linear quadratic Gaussian (Hunt et al, 1997; Munih et al, 1997), pole placement design (Hunt et al, 2001; Gollee et al, 2004), H-infinity (Holderbaum et al, 2004), artificial neural network, and sliding mode (Kobravi and Erfanian, 2012) control techniques. However, these control techniques suffer from limitations, including the need for voluntary trunk control, the lack of a strong physiological basis and/or high computational complexity limiting the operating frequency of thecontroller.…”

Section: Introductionmentioning

confidence: 99%

PID Controller Design for FES Applied to Ankle Muscles in Neuroprosthesis for Standing Balance

et al. 2017

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Closed-loop controlled functional electrical stimulation (FES) applied to the lower limb muscles can be used as a neuroprosthesis for standing balance in neurologically impaired individuals. The objective of this study was to propose a methodology for designing a proportional-integral-derivative (PID) controller for FES applied to the ankle muscles toward maintaining standing balance for several minutes and in the presence of perturbations. First, a model of the physiological control strategy for standing balance was developed. Second, the parameters of a PID controller that mimicked the physiological balance control strategy were determined to stabilize the human body when modeled as an inverted pendulum. Third, this PID controller was implemented using a custom-made Inverted Pendulum Standing Apparatus that eliminated the effect of visual and vestibular sensory information on voluntary balance control. Using this setup, the individual-specific FES controllers were tested in able-bodied individuals and compared with disrupted voluntary control conditions in four experimental paradigms: (i) quiet-standing; (ii) sudden change of targeted pendulum angle (step response); (iii) balance perturbations that simulate arm movements; and (iv) sudden change of targeted angle of a pendulum with individual-specific body-weight (step response). In paradigms (i) to (iii), a standard 39.5-kg pendulum was used, and 12 subjects were involved. In paradigm (iv) 9 subjects were involved. Across the different experimental paradigms and subjects, the FES-controlled and disrupted voluntarily-controlled pendulum angle showed root mean square errors of <1.2 and 2.3 deg, respectively. The root mean square error (all paradigms), rise time, settle time, and overshoot [paradigms (ii) and (iv)] in FES-controlled balance were significantly smaller or tended to be smaller than those observed with voluntarily-controlled balance, implying improved steady-state and transient responses of FES-controlled balance. At the same time, the FES-controlled balance required similar torque levels (no significant difference) as voluntarily-controlled balance. The implemented PID parameters were to some extent consistent among subjects for standard weight conditions and did not require prolonged individual-specific tuning. The proposed methodology can be used to design FES controllers for closed-loop controlled neuroprostheses for standing balance. Further investigation of the clinical implementation of this approach for neurologically impaired individuals is needed.

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“…[19,20] In order to control FES-evoked contraction levels, typical commercially available stimulators allow researchers and rehabilitation practitioners to regulate PA (or PD) and to maintain PD (or PA) constant. [21,22] Pulse charge (PA×PD) is a main determinant of motor unit recruitment. Increasing the PA produces a stronger depolarising drive that travels deeper into the underlying tissue [23] and recruits a greater number of motor units, [16] whereas adjusting the PD influences not only the number of recruited motor units, but may also influence the selectivity of motor unit recruitment, due to threshold differences that exist between axons of different diameter lying at the same distance from the stimulating electrodes.…”

Section: Introductionmentioning

confidence: 99%

Minimizing muscle fatigue through optimization of electrical stimulation parameters

Rouhani

Rodriguez

Bergquist

et al. 2016

JBEI

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Rapid onset of muscle fatigue in response to electrical stimulation is a major challenge when designing a neuroprosthesis. This study aimed to introduce a decision-making algorithm to optimize pulse amplitude and pulse duration, for current regulated electrical stimulators, to attain a target joint torque level while minimizing muscle fatigue. We measured ankle torque produced by different pairs of pulse amplitude and pulse duration applied to the plantar-flexors. In each session, we measured the maximum generated torque and calculated muscle fatigue (fatigue time and torque-time integral). Then, we determined the pulse amplitude and pulse duration pair that generated a target level of torque while minimizing muscle fatigue. High bilateral symmetry and day-to-day repeatability was observed for the torque time-series between the left and right plantar-flexors of each participant (median correlation coefficient = 0.95). Compared to the average fatigue obtained by various pulse amplitude and pulse duration pairs for a given level of torque, delivering pulses with the optimal pair reduced fatigue on average by 22.5% according to fatigue time and 6.6% according to torque-time integral. We created an empirical model describing how pulse amplitude and pulse duration can be modulated to generate specific levels of plantar-flexion torque with minimum muscle fatigue.

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A decentralized adaptive fuzzy robust strategy for control of upright standing posture in paraplegia using functional electrical stimulation

Cited by 31 publications

References 27 publications

Restoration of motor function following spinal cord injury via optimal control of intraspinal microstimulation: toward a next generation closed-loop neural prosthesis

Restoration of motor function following spinal cord injury via optimal control of intraspinal microstimulation: toward a next generation closed-loop neural prosthesis

PID Controller Design for FES Applied to Ankle Muscles in Neuroprosthesis for Standing Balance

Minimizing muscle fatigue through optimization of electrical stimulation parameters

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