Naji Alibeji

• PhD
• PostDoc Position at Case Western Reserve University

Mobility disorders caused by spinal cord injury (SCI), stroke, or progressive neurological diseases such as multiple sclerosis and amyotrophic lateral sclerosis, lead to a deterioration in quality of life. Resulting sequelae, such as pressure ulcers, depression, and urinary infections, require constant medical care throughout a patient's lifetime....

A hybrid walking neuroprosthesis that combines functional electrical stimulation (FES) with a powered lower limb exoskeleton can be used to restore walking in persons with paraplegia. It provides therapeutic benefits of FES and torque reliability of the powered exoskeleton. Moreover, by harnessing metabolic power of muscles via FES, the hybrid comb...

Neuromuscular electrical stimulation (NMES) is a promising technique to artificially activate muscles as a means to potentially restore the capability to perform functional tasks in persons with neurological disorders. A pervasive problem with NMES is that overstimulation of the muscle (among other factors) leads to rapid muscle fatigue, which limi...

Hybrid neuroprostheses that use both electric motor drives and functional electrical stimulation for the restoration of walking in persons with paraplegia have a promising potential. However, the hybrid actuation structure introduces effector redundancy, making the system complex and difficult to control. In this paper, preliminary experimental res...

The walking duration of gait restoration systems that use functional electrical stimulation (FES) is severely limited by the rapid onset of muscle fatigue. Alternatively, fully actuated orthoses can also be employed to restore walking in paraplegia. However, due to the high power consumption of electric motors the walking duration of such devices a...

A hybrid neuroprosthesis that combines human muscle power, elicited through functional electrical stimulation (FES), with a powered orthosis may be advantageous over a sole FES or a powered exoskeleton-based rehabilitation system. The hybrid system can conceivably overcome torque reduction due to FESinduced muscle fatigue by complementarily using t...

A widely accepted model of muscle force generation during neuromuscular electrical stimulation (NMES) is a second-order nonlinear musculoskeletal dynamics cascaded to a delayed first-order muscle activation dynamics. However, most nonlinear NMES control methods have either neglected the muscle activation dynamics or used ad hoc strategies to tackle...

Robust delay compensation techniques for uncertain nonlinear systems with unknown input delays are, in general, lacking. The result in this brief extends a modified proportional-integral derivative (PID)-type controller that contains a distributed delay term to Euler-Lagrange systems with an unknown constant input delay. Additive disturbances and u...

Currently, a telerehabilitation system includes a therapist and a patient where the therapist interacts with the patient, typically via a verbal and visual communication, for assessment and supervision of rehabilitation interventions. This mechanism often fails to provide physical assistance, which is a modus operandi during physical therapy or occ...

To restore walking and standing function in persons with paraplegia, a hybrid walking neuroprosthesis that combines a powered exoskeleton and functional electrical stimulation (FES) can be more advantageous than sole FES or powered exoskeleton technologies. However, the hybrid actuation structure introduces certain control challenges: actuator redu...

Hybrid neuroprostheses that use both electric motor drives and functional electrical stimulation for the restoration of walking in persons with paraplegia have a promising potential. However, the hybrid actuation structure introduces effector redundancy, making the system complex and difficult to control. In this paper we design a low-dimensional c...

A hybrid neuroprosthesis that uses an electric motor-based wearable exoskeleton and functional electrical stimulation (FES) has a promising potential to restore walking in persons with paraplegia. A hybrid actuation structure introduces effector redundancy, making its automatic control a challenging task because multiple muscles and additional elec...

One of the major limitations of functional electrical stimulation (FES) is the rapid onset of muscle fatigue. Minimizing stimulation is the key to decreasing the adverse effects of muscle fatigue caused by FES. Optimal control can be used to compute the minimum amount of stimulation necessary to produce a desired motion. In this paper, a gradient p...

Neuromuscular electrical stimulation (NMES) is the application of an external electrical potential across a neuromuscular effector to generate desired limb movements. Some of the challenges faced during closed-loop control of NMES include: an electromechanical delay (EMD) in the neuromuscular activation dynamics and uncertain nonlinear musculoskele...

Electromechanical delay (EMD) and uncertain nonlinear muscle dynamics can cause destabilizing effects and performance loss during closed-loop control of neuromuscular electrical stimulation (NMES). Linear control methods for NMES often perform poorly due to these technical challenges. A new predictor-based closed-loop controller called proportional...

Minimizing the amount of electrical stimulation can potentially mitigate the adverse effects of muscle fatigue during functional electrical stimulation (FES) induced limb movements. A gradient projection-based model predictive controller is presented for optimal control of a knee extension elicited via FES. A control Lyapunov function was used as a...

A position-synchronization controller for functional electrical stimulation (FES)-based telerehabilitation was designed. The developed controller synchronizes an FES-driven human limb with a remote physical therapist's manipulator despite constant bilateral communication delays. The control design overcomes a major stability analysis challenge: the...

To date, a functional electrical stimulation (FES)-based walking technology is incapable of enabling a paraplegic user to walk more than a few hundred meters. This is primarily due to the rapid onset of muscle fatigue, which causes limited torque generation capability of the lower-limb muscles. A hybrid walking neuroprosthesis that combines FES wit...

Through the application of functional electrical stimulation (FES) individuals with paraplegia can regain lost walking function. However, due to the rapid onset of muscle fatigue, the walking duration obtained with an FES-based neuroprosthesis is often relatively short. The rapid muscle fatigue can be compensated for by using a hybrid system that u...

In this paper, we show the feasibility of remotely controlling the elbow extension through functional electrical stimulation (FES) of the triceps muscle. Particularly, we present the experimental results obtained with the new automatic control method, designed to achieve position tracking between a user and the remote manipulator device. The major...

A combination of functional electrical stimulation (FES) and an orthosis can be used to restore lower limb function in persons with paraplegia. This artificial intervention may allow them to regain the ability to walk again, however, only for short time durations. To improve the time duration of hybrid (FES and orthosis) gait, the muscle fatigue du...