scholarly journals Switched Control of Motor Assistance and Functional Electrical Stimulation for Biceps Curls

2020 ◽  
Vol 10 (22) ◽  
pp. 8090
Author(s):  
Courtney Rouse ◽  
Brendon Allen ◽  
Warren Dixon
Keyword(s):  
Electrical Stimulation ◽  
Functional Electrical Stimulation ◽  
Biceps Brachii ◽  
Neurological Impairment ◽  
Rehabilitation Robotics ◽  
Limiting Factor ◽  
Robot System ◽  
Physical Effort ◽  
Slow Progress ◽  
And Performance

Rehabilitation robotics is an emerging tool for motor recovery from various neurological impairments. However, balancing the human and robot contribution is an open problem. While the motor input can reduce fatigue, which is often a limiting factor of functional electrical stimulation (FES) exercises, too much assistance can slow progress. For a person with a neurological impairment, FES can assist by strategically contracting their muscle(s) to achieve a desired limb movement; however, feasibility can be limited due to factors such as subject comfort, muscle mass, unnatural muscle fiber recruitment, and stimulation saturation. Thus, motor assistance in addition to FES can be useful for prolonging exercise while still ensuring physical effort from the person. In this paper, FES is applied to the biceps brachii to perform biceps curls, and motor assistance is applied intermittently whenever the FES input reaches a pre-set comfort threshold. Exponential stability of the human–robot system is proven with a Lyapunov-like switched systems stability analysis. Experimental results from participants with neurological conditions demonstrate the feasibility and performance of the controller.

Varying Motor Assistance During Biceps Curls Induced via Functional Electrical Stimulation

2018 ◽  
Author(s):  
Courtney A. Rouse ◽  
Christian A. Cousin ◽  
Victor H. Duenas ◽  
Warren E. Dixon
Keyword(s):  
Electrical Stimulation ◽  
Stability Analysis ◽  
Exponential Stability ◽  
Functional Electrical Stimulation ◽  
Switched Systems ◽  
Biceps Brachii ◽  
Robot Assisted ◽  
Robot System ◽  
Rehabilitation Protocols ◽  
And Performance

Robot-assisted therapy has been established as a useful rehabilitation tool for motor recovery in people with various neurological impairments; however, balancing human and robot contribution, such that the target muscle is sufficiently exercised, is necessary to improve the outcome of rehabilitation protocols. Functional Electrical Stimulation (FES) can assist a person to move their limb by contracting the muscle; however, motor assistance is often necessary to accurately follow a desired limb trajectory, especially since stimulation can be limited due to various factors (e.g., subject comfort, stimulation saturation). In this paper, a motor is tasked with intermittently assisting the FES-activated biceps brachii in tracking a desired forearm trajectory whenever the FES input reaches a pre-set comfort threshold. A Lyapunov-like switched systems stability analysis is used to prove exponential stability of the human-robot system. Preliminary experiments demonstrate the feasibility and performance of the controller on two subjects with neurological impairments.

scholarly journals Comparison of strategies and performance of functional electrical stimulation cycling in spinal cord injury pilots for competition in the first ever CYBATHLON

2017 ◽  
Vol 27 (4) ◽  
Author(s):  
Christine Azevedo Coste ◽  
Vance Bergeron ◽  
Rik Berkelmans ◽  
Emerson Fachin Martins ◽  
Ché Fornusek ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Electrical Stimulation ◽  
Functional Electrical Stimulation ◽  
Muscular Contraction ◽  
Cord Injury ◽  
Clinical Environments ◽  
And Performance ◽  
Mechanical Devices ◽  
Complete Spinal Cord Injury

Functional Electrical Stimulation (FES) can elicit muscular contraction and restore motor function in paralyzed limbs. FES is a rehabilitation technique applied to various sensorimotor deficiencies and in different functional situations, e.g. grasping, walking, standing, transfer, cycling and rowing. FES can be combined with mechanical devices. FES-assisted cycling is mainly used in clinical environments for training sessions on cycle ergometers, but it has also been adapted for mobile devices, usually tricycles. In October 2016, twelve teams participated in the CYBATHLON competition in the FES-cycling discipline for persons with motor-complete spinal cord injury. It was the first event of this kind and a wide variety of strategies, techniques and designs were employed by the different teams in the competition. The approaches of the teams are detailed in this special issue. We hope that the knowledge contained herein, together with recent positive results of FES for denervated degenerating muscles, will provide a solid basis to encourage improvements in FES equipment and open new opportunities for many patients in need of safe and effective FES management. We hope to see further developments and/or the benefit of new training strategies at future FES competitions, e.g. at the Cybathlon 2020 (www.cybathlon.ethz.ch).

Stable Cadence Tracking of Admitting Functional Electrical Stimulation Cycle

2018 ◽  
Author(s):  
Christian A. Cousin ◽  
Victor H. Duenas ◽  
Courtney A. Rouse ◽  
Warren E. Dixon
Keyword(s):  
Electrical Stimulation ◽  
Functional Electrical Stimulation ◽  
Rehabilitation Robotics ◽  
Combined Cycle ◽  
Tracking Errors ◽  
Human Machine Interaction ◽  
Leg Muscles ◽  
Strength Recovery ◽  
Machine Interaction ◽  
Single Set

Rehabilitation robotics and functional electrical stimulation (FES) are two promising methods of rehabilitation for people with neurological disorders. In motorized FES cycling, both the rider and the motorized cycle must be controlled for cooperative human-machine interaction. While rehabilitation goals vary widely, FES cycling traditionally rejects rider disturbances to accomplish cadence and power tracking; however, this paper ensures that the cycle accommodates the rider without rejecting rider disturbances as a means to promote function and strength recovery while ensuring rider safety. A cadence and admittance controller are developed to activate the cycle’s electric motor and the rider’s leg muscles through FES when kinematically efficient. Using a single set of combined cycle-rider dynamics, a Lyapunov-like switched systems analysis is conducted to conclude global exponential cadence tracking. A subsequent passivity analysis is conducted to show the admittance controller is passive with respect to the rider. For a desired cadence of 50 RPM, preliminary experiments on one able-bodied participant and one participant with spina bifida demonstrate tracking errors of −0.07±2.59 RPM and −0.20±3.86 RPM, respectively.

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