Superficial FES Techniques for Improving Hand Dexterity in Neurorehabilitation.
| dc.contributor.advisor | Aqueveque Navarro, Pablo Esteban | es |
| dc.contributor.advisor | Andrews, Brian James | es |
| dc.contributor.advisor | Saavedra Rodríguez, Francisco Andrés | es |
| dc.contributor.author | Sáez Acuña, Javier Ignacio | es |
| dc.date.accessioned | 2025-12-10T17:41:21Z | |
| dc.date.available | 2025-12-10T17:41:21Z | |
| dc.date.issued | 2025 | |
| dc.description | Tesis presentada para optar al grado de Magíster en Ciencias de la Ingeniería con mención en Ingeniería Eléctrica. | es |
| dc.description.abstract | La presente tesis aborda los desafíos asociados con los déficits motores del miembro superior posteriores al accidente cerebrovascular. Centrando la investigación en la FES como modalidad terapéutica, se busca mejorar la precisión, eficacia y accesibilidad de la estimulación eléctrica superficial para la rehabilitación de la destreza manual. Las técnicas actuales presentan limitaciones relevantes, como baja selectividad muscular y malestar durante la terapia. La literatura destaca tres conceptos para optimizar neuroprótesis no invasivas: (1) rediseño geométrico de electrodos hacia configuraciones concéntricas para focalizar el campo eléctrico; (2) uso de manufactura aditiva para crear nuevas geometrías; y (3) aplicación de estímulos de media frecuencia para reducir la impedancia cutánea y mejorar la comodidad. No obstante, persisten vacíos respecto al impacto de estos enfoques en terapias FES, lo que constituye el foco de esta tesis. La metodología comprende cuatro fases: diseño de electrodos, modelación computacional, prototipado mediante manufactura aditiva y pruebas in vivo en sujetos sanos. Los resultados indican que los electrodos concéntricos generan un campo eléctrico más localizado (r₀.₅: 16,3 mm vs. 24,4 mm), y que el proceso de impresión 3D permitió fabricar electrodos flexibles y biocompatibles a bajo costo (~2,4 USD). En pruebas in vivo, la selectividad aumentó un 32% y la estimulación interferencial redujo significativamente el malestar (VAS: 3,75 ± 1,98 a 2,12 ± 1,73). En conjunto, la tesis demuestra que optimizar la geometría de los electrodos y los parámetros de estimulación mejora la selectividad y la comodidad en FES superficial, aportando bases para futuras terapias no invasivas orientadas a tareas y personalizadas para cada paciente. | es |
| dc.description.abstract | The proposed thesis aims to address the pressing challenges associated with post-stroke upper limb motor deficits. By focusing on FES as a therapeutic modality, this research seeks to refine the precision, efficacy, and accessibility of surface electrical stimulation techniques, advancing hand dexterity rehabilitation. Current approaches for upper limb neurorehabilitation face significant limitations, including low selectivity in muscle activation and considerable discomfort during therapy. To enhance the applicability of non-invasive motor neuroprostheses, three key concepts have emerged in the literature: (1) modifying electrode geometry to concentric designs, which can focalize the electric field and improve selectivity; (2) utilizing additive manufacturing techniques to create novel electrode shapes; and (3) employing medium-frequency stimuli to reduce skin impedance, enhance comfort and enable a precise control over the stimulation area. Despite their potential, there are notable gaps in the literature regarding the application of these concepts to FES therapies and their resulting effects. Addressing these gaps forms the central objective of this thesis. The methodology encompasses four core phases: (1) electrode design (2) computational modeling, (3) prototyping through additive manufacturing techniques and (4) in-vivo testing conducted on healthy subjects. The results demonstrated that concentric electrodes produced a more localized and selective electric field, as confirmed by qualitative FEM visualizations and quantitative metrics showing a focality radius (r₀.₅) of 16.3 mm compared to 24.4 mm for square electrodes. The proposed 3D-printing based prototyping process enabled the rapid fabrication of flexible, biocompatible electrodes with an average unit cost of approximately 2.4 USD, facilitating efficient iteration between design and experimentation. In vivo evaluations showed a 32% increase in selectivity index (0.723 ± 0.175 vs. 0.546 ± 0.098, p < 0.01) for concentric electrodes and a significant reduction in discomfort with interferential current stimulation, decreasing VAS scores from 3.75 ± 1.98 to 2.12 ± 1.73 (p < 0.05). This thesis contributes to the domain of neurorehabilitation by demonstrating that optimizing electrode geometry and stimulation waveform parameters can significantly enhance both selectivity and comfort in surface FES. These advances help bridge the gap between complex neuroprosthetic systems and accessible, clinically applicable stimulation technologies. The validated hypothesis establishes a solid foundation for the future integration of these methods into task-oriented, patient-specific neurorehabilitation therapies. | en |
| dc.description.campus | Concepción | es |
| dc.description.departamento | Departamento de Ingeniería Eléctrica | es |
| dc.description.facultad | Facultad de Ingeniería | es |
| dc.description.sponsorship | ANID, Proyecto N°22250256 | es |
| dc.identifier.uri | https://repositorio.udec.cl/handle/11594/13489 | |
| dc.language.iso | en | en |
| dc.publisher | Universidad de Concepción | es |
| dc.rights | CC BY-NC-ND 4.0 DEED Attribution-NonCommercial-NoDerivs 4.0 International | en |
| dc.rights.uri | https://creativecommons.org/licenses/by-nc-nd/4.0/ | |
| dc.subject | Motor ability | en |
| dc.subject | Physical therapy | en |
| dc.subject | Medical rehabilitation | en |
| dc.subject | Cerebrovascular diseases | en |
| dc.subject.ods | Buena SALUD | es |
| dc.title | Superficial FES Techniques for Improving Hand Dexterity in Neurorehabilitation. | en |
| dc.type | Thesis | en |