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Development and Validation of a Dry Electrode Array for sEMG Recording and Hand Movement Recognition
Desarrollo y validación de un arreglo de electrodos secos para la adquisición de señales sEMG y el reconocimiento de los movimientos de la mano
DOI:
https://doi.org/10.15446/ing.investig.106558Keywords:
dry electrodes, Bland-Altman, anatomical positioning array, hand movement classification (en)electrodos secos, Bland-Altman, arreglo de posicionamiento anatómico, clasificación de movimientos de la mano (es)
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Surface electromyography (sEMG) signals are an indirect measurement of muscle activity, and their applications range from biomechanics to control and rehabilitation. Hand movement recognition is a very difficult endeavor due to forearm anatomy. Hence, a multichannel approach for signal acquisition and processing is required. Conventional electrodes can limit the ease-of-use and repeatability of multi-channel sEMG recordings. New techniques have been proposed in this regard, with dry electrodes being one of them. Dry electrode technology has enabled the design of better donning and doffing procedures for multichannel sEMG recording, particularly for rehabilitation and prosthetic applications. However, there is a debate about the quality of the signals recorded with them and their usefulness for the recognition of multiple hand movements. To mitigate these quality issues, this work proposes an array of reusable stainless steel dry electrodes for multichannel sEMG recording with a design that facilitates its positioning on the forearm. The dry electrodes were characterized through electrical impedance measures and a Bland-Altman test. They were found to have similar characteristics to standard, disposable sEMG pre-gelled electrodes. For placement repeatability and application feasibility, an anatomy-based electrode positioning protocol was implemented with 17 healthy subjects and six hand movements. To evaluate the application feasibility of the electrode array, a feed-forward artificial neural network was trained to classify signals from the six movements, with a 97,86±0,58% accuracy. The amplitude of the sEMG signals for two antagonist movements was compared, finding a 24,81% variation. The dry electrode array showed feasibility in acquiring and classifying sEMG signals of hand movements with high accuracy.
Las señales de electromiografía de superficie (sEMG) son una medida indirecta de la actividad muscular, y sus aplicaciones van desde biomecánica hasta control y rehabilitación. La identificación de movimientos de la mano es una tarea muy complicada debido a la anatomía del antebrazo, por lo que se requiere un enfoque multicanal para adquisición y procesamiento de señales. Los electrodos convencionales pueden limitar la facilidad de uso y la repetibilidad de los registros sEMG multicanal. Se han propuesto nuevas técnicas para ello, entre ellas los electrodos secos. La tecnología de electrodos secos ha permitido el diseño de mejores procedimientos de colocación y remoción para registro sEMG multicanal, particularmente en aplicaciones de rehabilitación y prótesis. Sin embargo, existe un debate sobre la calidad de las señales registradas con ellos y su utilidad para el reconocimiento de múltiples movimientos de la mano. Para mitigar estos problemas de calidad, se propone un arreglo de electrodos secos reutilizables de acero inoxidable para registro sEMG multicanal con un diseño que facilita su posicionamiento en el antebrazo. Estos electrodos se caracterizaron mediante mediciones de impedancia eléctrica y una prueba Bland-Altman. Se encontró que tienen características similares a los electrodos pregelados desechables estándar para sEMG. Para la repetibilidad de la colocación y su viabilidad de aplicación, se implementó un protocolo de colocación de electrodos basado en la anatomía con 17 sujetos sanos y seis movimientos de la mano. Finalmente se entrenó una red neuronal artificial prealimentada para clasificar señales de los seis movimientos, con una precisión del 97,86±0,58 %. Se comparó la amplitud de las señales sEMG para dos movimientos antagonistas, encontrando una variación del 24,81 %. El arreglo de electrodos secos mostró viabilidad para adquirir y clasificar registros sEMG de los movimientos de la mano con gran precisión.
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Copyright (c) 2024 Cinthya Lourdes Toledo Peral, Ana Isabel Martín-Vignon-Whaley, Jorge Airy Mercado-Gutierrez, Arturo Vera-Hernandez, Lorenzo Leija-Salas, Josefina Gutierrez-Martinez
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