Targeting Transcutaneous Spinal Cord Stimulation Using a Supervised Machine Learning Approach Based on Mechanomyography

Transcutaneous spinal cord stimulation (tSCS) provides a promising therapy option for individuals with injured spinal cords and multiple sclerosis patients with spasticity and gait deficits. Before the therapy, the examiner determines a suitable electrode position and stimulation current for a contr...

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Main Authors: Eira Lotta Spieker, Ardit Dvorani, Christina Salchow-Hömmen, Carolin Otto, Klemens Ruprecht, Nikolaus Wenger, Thomas Schauer
Format: Article
Language:English
Published: MDPI AG 2024-01-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/24/2/634
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author Eira Lotta Spieker
Ardit Dvorani
Christina Salchow-Hömmen
Carolin Otto
Klemens Ruprecht
Nikolaus Wenger
Thomas Schauer
author_facet Eira Lotta Spieker
Ardit Dvorani
Christina Salchow-Hömmen
Carolin Otto
Klemens Ruprecht
Nikolaus Wenger
Thomas Schauer
author_sort Eira Lotta Spieker
collection DOAJ
description Transcutaneous spinal cord stimulation (tSCS) provides a promising therapy option for individuals with injured spinal cords and multiple sclerosis patients with spasticity and gait deficits. Before the therapy, the examiner determines a suitable electrode position and stimulation current for a controlled application. For that, amplitude characteristics of posterior root muscle (PRM) responses in the electromyography (EMG) of the legs to double pulses are examined. This laborious procedure holds potential for simplification due to time-consuming skin preparation, sensor placement, and required expert knowledge. Here, we investigate mechanomyography (MMG) that employs accelerometers instead of EMGs to assess muscle activity. A supervised machine-learning classification approach was implemented to classify the acceleration data into no activity and muscular/reflex responses, considering the EMG responses as ground truth. The acceleration-based calibration procedure achieved a mean accuracy of up to 87% relative to the classical EMG approach as ground truth on a combined cohort of 11 healthy subjects and 11 patients. Based on this classification, the identified current amplitude for the tSCS therapy was in 85%, comparable to the EMG-based ground truth. In healthy subjects, where both therapy current and position have been identified, 91% of the outcome matched well with the EMG approach. We conclude that MMG has the potential to make the tuning of tSCS feasible in clinical practice and even in home use.
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spelling doaj.art-748cd52aeea14cdb8e08332b5ba7b0202024-01-29T14:17:30ZengMDPI AGSensors1424-82202024-01-0124263410.3390/s24020634Targeting Transcutaneous Spinal Cord Stimulation Using a Supervised Machine Learning Approach Based on MechanomyographyEira Lotta Spieker0Ardit Dvorani1Christina Salchow-Hömmen2Carolin Otto3Klemens Ruprecht4Nikolaus Wenger5Thomas Schauer6Department of Neurology, Charité–Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, GermanyControl Systems Group, Technische Universität Berlin, Einsteinufer 17, 10587 Berlin, GermanyDepartment of Neurology, Charité–Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, GermanyDepartment of Neurology, Charité–Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, GermanyDepartment of Neurology, Charité–Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, GermanyDepartment of Neurology, Charité–Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, GermanyControl Systems Group, Technische Universität Berlin, Einsteinufer 17, 10587 Berlin, GermanyTranscutaneous spinal cord stimulation (tSCS) provides a promising therapy option for individuals with injured spinal cords and multiple sclerosis patients with spasticity and gait deficits. Before the therapy, the examiner determines a suitable electrode position and stimulation current for a controlled application. For that, amplitude characteristics of posterior root muscle (PRM) responses in the electromyography (EMG) of the legs to double pulses are examined. This laborious procedure holds potential for simplification due to time-consuming skin preparation, sensor placement, and required expert knowledge. Here, we investigate mechanomyography (MMG) that employs accelerometers instead of EMGs to assess muscle activity. A supervised machine-learning classification approach was implemented to classify the acceleration data into no activity and muscular/reflex responses, considering the EMG responses as ground truth. The acceleration-based calibration procedure achieved a mean accuracy of up to 87% relative to the classical EMG approach as ground truth on a combined cohort of 11 healthy subjects and 11 patients. Based on this classification, the identified current amplitude for the tSCS therapy was in 85%, comparable to the EMG-based ground truth. In healthy subjects, where both therapy current and position have been identified, 91% of the outcome matched well with the EMG approach. We conclude that MMG has the potential to make the tuning of tSCS feasible in clinical practice and even in home use.https://www.mdpi.com/1424-8220/24/2/634transcutaneous spinal cord stimulation (tSCS)accelerationmechanomyography (MMG)supervised classificationmultiple sclerosis (MS)spinal cord injury (SCI)
spellingShingle Eira Lotta Spieker
Ardit Dvorani
Christina Salchow-Hömmen
Carolin Otto
Klemens Ruprecht
Nikolaus Wenger
Thomas Schauer
Targeting Transcutaneous Spinal Cord Stimulation Using a Supervised Machine Learning Approach Based on Mechanomyography
Sensors
transcutaneous spinal cord stimulation (tSCS)
acceleration
mechanomyography (MMG)
supervised classification
multiple sclerosis (MS)
spinal cord injury (SCI)
title Targeting Transcutaneous Spinal Cord Stimulation Using a Supervised Machine Learning Approach Based on Mechanomyography
title_full Targeting Transcutaneous Spinal Cord Stimulation Using a Supervised Machine Learning Approach Based on Mechanomyography
title_fullStr Targeting Transcutaneous Spinal Cord Stimulation Using a Supervised Machine Learning Approach Based on Mechanomyography
title_full_unstemmed Targeting Transcutaneous Spinal Cord Stimulation Using a Supervised Machine Learning Approach Based on Mechanomyography
title_short Targeting Transcutaneous Spinal Cord Stimulation Using a Supervised Machine Learning Approach Based on Mechanomyography
title_sort targeting transcutaneous spinal cord stimulation using a supervised machine learning approach based on mechanomyography
topic transcutaneous spinal cord stimulation (tSCS)
acceleration
mechanomyography (MMG)
supervised classification
multiple sclerosis (MS)
spinal cord injury (SCI)
url https://www.mdpi.com/1424-8220/24/2/634
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