Browsing by Keyword "Functional electrical stimulation"
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Item Analysis of the movements generated by a multi-field functional electrical stimulation device for upper extremity rehabilitation(2022-10) Martín-Odriozola, Aitor; Rodríguez-de-Pablo, Cristina; Caceres-Salegi, Ane; García-Calleja, Andrea; Marín-Ojea, Juan Ignacio; Hernández, Erik; Imatz-Ojanguren, Eukene; Keller, Thierry; Zabaleta-Rekondo, Haritz; Martín‐Odriozola, Aitor; Rodríguez‐de‐Pablo, Cristina; Caceres‐Salegi, Ane; García‐Calleja, Andrea; Marín‐Ojea, Juan Ignacio; Imatz‐Ojanguren, Eukene; Zabaleta‐Rekondo, Haritz; Medical Technologies; Tecnalia Research & InnovationBackground: The most common chronic sequela after stroke is the loss of arm function, and functional electrical stimulation (FES) applied to the forearm muscles is one of the options to treat it. Surface multi-field electrodes have emerged, showing a great potential to improve the selectivity of the stimulation, delay muscle fatigue, and provide easier donning and doffing. The muscular selectivity takes on special relevance in the rehabilitation of the upper extremity as hand dexterity requires a wide diversity of specific muscle actions. Methods: This pilot study analyses the movements generated in the wrist and fingers using a commercial multi-field technology-based FES device (Fesia Grasp). The study included five patients with hemiplegic subacute stroke, in which scanning of all cathodes of the electrode was carried out daily for 5 days, in two different forearm positions, with the resulting movements being labeled by experienced therapists. Results: The aim of this pilot study was to determine if there were differences between subjects and between forearm positions in terms of produced movements. Movements of the wrist (two movements) and the fingers (six movements) could be achieved in two different forearm positions. Conclusions: The multi-field electrode of Fesia Grasp enables to generate a wide range of movements of the hand in different positions. This fact could allow to produce more physiological movement patterns during the rehabilitation process with FES, which could have a beneficial effect on the recovery of patients with neurological diseases.Item A decision support system for electrode shaping in multi-pad FES foot drop correction(2017-07-03) Malešević, Jovana; Dedijer Dujović, Suzana; Savić, Andrej M.; Konstantinović, Ljubica; Vidaković, Aleksandra; Bijelić, Goran; Malešević, Nebojša; Keller, Thierry; Tecnalia Research & Innovation; SG; MercadoBackground: Functional electrical stimulation (FES) can be applied as an assistive and therapeutic aid in the rehabilitation of foot drop. Transcutaneous multi-pad electrodes can increase the selectivity of stimulation; however, shaping the stimulation electrode becomes increasingly complex with an increasing number of possible stimulation sites. We described and tested a novel decision support system (DSS) to facilitate the process of multi-pad stimulation electrode shaping. The DSS is part of a system for drop foot treatment that comprises a customdesigned multi-pad electrode, an electrical stimulator, and an inertial measurement unit. Methods: The system was tested in ten stroke survivors (3-96 months post stroke) with foot drop over 20 daily sessions. The DSS output suggested stimulation pads and parameters based on muscle twitch responses to short stimulus trains. The DSS ranked combinations of pads and current amplitudes based on a novel measurement of the quality of the induced movement and classified them based on the movement direction (dorsiflexion, plantar flexion, eversion and inversion) of the paretic foot. The efficacy of the DSS in providing satisfactory pad-current amplitude choices for shaping the stimulation electrode was evaluated by trained clinicians. The range of paretic foot motion was used as a quality indicator for the chosen patterns. Results: The results suggest that the DSS output was highly effective in creating optimized FES patterns. The position and number of pads included showed pronounced inter-patient and inter-session variability; however, zones for inducing dorsiflexion and plantar flexion within the multi-pad electrode were clearly separated. The range of motion achieved with FES was significantly greater than the corresponding active range of motion (p < 0.05) during the first three weeks of therapy. Conclusions: The proposed DSS in combination with a custom multi-pad electrode design covering the branches of peroneal and tibial nerves proved to be an effective tool for producing both the dorsiflexion and plantar flexion of a paretic foot. The results support the use of multi-pad electrode technology in combination with automatic electrode shaping algorithms for the rehabilitation of foot drop.Item Neuro-fuzzy models for hand movements induced by functional electrical stimulation in able-bodied and hemiplegic subjects(2016-11-01) Imatz-Ojanguren, Eukene; Irigoyen, Eloy; Valencia-Blanco, David; Keller, Thierry; Tecnalia Research & Innovation; Medical TechnologiesFunctional Electrical Stimulation (FES) may be effective as a therapeutic treatment for improving functional reaching and grasping. Upper-limb FES models for predicting joint torques/angles from stimulation parameters can be useful to support the iterative design and development of neuroprostheses. Most such models focused on shoulder or elbow joints and were defined for fixed electrode configurations. This work proposes the use of a Recurrent Fuzzy Neural Network (RFNN) for modeling FES induced wrist, thumb, and finger movements based on surface multi-field electrodes and kinematic data from able-bodied and neurologically impaired subjects. Different combinations of structure parameters comprising fuzzy term numbers and feedback approaches were tested and analyzed in order to see their effect on the model performance for six subjects. The results showed mean success rates in the range from 60% to 99% and best success rates in the range from 78% to 100% on test data for all subjects. No common trend was found across subjects regarding structure parameters. The model showed the ability to successfully reproduce the response to FES for both able-bodied and hemiplegic subjects at least with one of the tested combinations.Item Reinforcement Learning for Hand Grasp with Surface Multi-field Neuroprostheses(Springer International Publishing, 2017) Imatz-Ojanguren, Eukene; Irigoyen, Eloy; Keller, Thierry; Lopez-Guede, Jose Manuel; Herrero, Alvaro; Quintian, Hector; Grana, Manuel; Etxaniz, Oier; Corchado, Emilio; Tecnalia Research & InnovationHand grasp is a complex system that plays an important role in the activities of daily living. Upper-limb neuroprostheses aim at restor- ing lost reaching and grasping functions on people su ering from neural disorders. However, the dimensionality and complexity of the upper-limb makes the neuroprostheses modeling and control challenging. In this work we present preliminary results for checking the feasibility of using a re- inforcement learning (RL) approach for achieving grasp functions with a surface multi- eld neuroprosthesis for grasping. Grasps from 20 healthy subjects were recorded to build a reference for the RL system and then two di erent award strategies were tested on simulations based on neuro- fuzzy models of hemiplegic patients. These rst results suggest that RL might be a possible solution for obtaining grasp function by means of multi- eld neuroprostheses in the near future.Item Smart Protocols for Physical Therapy of Foot Drop Based on Functional Electrical Stimulation: A Case Study: A case study(2021-04-26) Malešević, Jovana; Konstantinović, Ljubica; Bijelić, Goran; Malešević, Nebojša; SG; MercadoFunctional electrical stimulation (FES) is used for treating foot drop by delivering electrical pulses to the anterior tibialis muscle during the swing phase of gait. This treatment requires that a patient can walk, which is mostly possible in the later phases of rehabilitation. In the early phase of recovery, the therapy conventionally consists of stretching exercises, and less commonly of FES delivered cyclically. Nevertheless, both approaches minimize patient engagement, which is inconsistent with recent findings that the full rehabilitation potential could be achieved by an active psycho-physical engagement of the patient during physical therapy. Following this notion, we proposed smart protocols whereby the patient sits and ankle movements are FES-induced by self-control. In six smart protocols, movements of the paretic ankle were governed by the non-paretic ankle with different control strategies, while in the seventh voluntary movements of the paretic ankle were used for stimulation triggering. One stroke survivor in the acute phase of recovery participated in the study. During the therapy, the patient’s voluntary ankle range of motion increased and reached the value of normal gait after 15 sessions. Statistical analysis did not reveal the differences between the protocols in FES-induced movements.