Variation of Finger Activation Patterns Post-stroke Through Non-invasive Nerve Stimulation

Abstract

Purpose: A transcutaneous proximal nerve stimulation technique utilizing an electrode grid along the nerve bundles has previously shown flexible activation of multiple fingers. This case study aimed to further demonstrate the ability of this novel stimulation technique to induce various finger grasp patterns in a stroke survivor.Methods: An individual with chronic hemiplegia and severe hand impairment was recruited. Electrical stimulation was delivered to different pairs of an electrode grid along the ulnar and median nerves to selectively activate different finger flexor muscles, with an automated electrode switching method. The resultant individual isometric flexion forces and forearm flexor high-density electromyography (HDEMG) were acquired to evaluate the finger activation patterns. A medium and low level of overall activation were chosen to gauge the available finger patterns for both the contralateral and paretic hands. All the flexion forces were then clustered to categorize the different types of grasp patterns.Results: Both the contralateral and paretic sides demonstrated various force clusters including single and multi-finger activation patterns. The contralateral hand showed finger activation patterns mainly centered on median nerve activation of the index, middle, and ring fingers. The paretic hand exhibited fewer total activation patterns, but still showed activation of all four fingers in some combination.Conclusion: Our results show that electrical stimulation at multiple positions along the proximal nerve bundles can elicit a select variety of finger activation patterns even in a stroke survivor with minimal hand function. This system could be further implemented for better rehabilitative training to help induce functional grasp patterns or to help regain muscle mass.

Volitional EMG Estimation Method during Functional Electrical Stimulation by Dual-Channel Surface EMGs

“…In addition, the signals become more similar when the electrodes are more closely attached. This characteristic has been experimentally demonstrated in a previous study [ 30 ], although the experimental conditions are different from those used in this study. This assumption is quite useful because if two EMG electrodes are closely attached to a stimulated muscle, it is possible to simultaneously measure the same FES-induced signals and randomly different vEMG signals, which are generated because of the characteristic of Gaussian random signals, through each channel.…”

A portable, programmable, multichannel stimulator with high compliance voltage for noninvasive neural stimulation of motor and sensory nerves in humans

“…To activate motor fibers, stimulation is traditionally applied directly above the muscle belly to cause the muscle nearest the electrode to contract. More recently, stimulation has been applied to the proximal nerve truck to activate motor units that innervate distal and deeper muscles 15 – 19 . Sensory fibers can be activated through either electrocutaneous or transcutaneous stimulation.…”

Rapid Detection of Cardiac Pathologies by Neural Networks Using ECG Signals (1D) and sECG Images (3D)

“…This study used six channels to convert it into a three-dimensional sECG. These concepts have been taken from surface electromyography (sEMG) studies and adapted to meet the stated objectives [9,[11][12][13][14].…”

“…This study used six channels to convert it into a three-dimensional sECG. These concepts have been taken from surface electromyography (sEMG) studies and adapted to meet the stated objectives [9,[11][12][13][14]. Leads are specific electrode arrangements that record the potential difference generated by cardiac electrical activity at these points [6].…”