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1.
Phys Eng Sci Med ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38954380

RESUMO

Recognizing user intention in reach-to-grasp motions is a critical challenge in rehabilitation engineering. To address this, a Machine Learning (ML) algorithm based on the Extreme Learning Machine (ELM) was developed for identifying motor actions using surface Electromyography (sEMG) during continuous reach-to-grasp movements, involving multiple Degrees of Freedom (DoFs). This study explores feature extraction methods based on time domain and autoregressive models to evaluate ELM performance under different conditions. The experimental setup encompassed variations in neuron size, time windows, validation with each muscle, increase in the number of features, comparison with five conventional ML-based classifiers, inter-subjects variability, and temporal dynamic response. To evaluate the efficacy of the proposed ELM-based method, an openly available sEMG dataset containing data from 12 participants was used. Results highlight the method's performance, achieving Accuracy above 85%, F-score above 90%, Recall above 85%, Area Under the Curve of approximately 84% and compilation times (computational cost) of less than 1 ms. These metrics significantly outperform standard methods (p < 0.05). Additionally, specific trends were found in increasing and decreasing performance in identifying specific tasks, as well as variations in the continuous transitions in the temporal dynamics response. Thus, the ELM-based method effectively identifies continuous reach-to-grasp motions through myoelectric data. These findings hold promise for practical applications. The method's success prompts future research into implementing it for more reliable and effective Human-Machine Interface (HMI) control. This can revolutionize real-time upper limb rehabilitation, enabling natural and complex Activities of Daily Living (ADLs) like object manipulation. The robust results encourages further research and innovative solutions to improve people's quality of life through more effective interventions.

2.
Biomed Phys Eng Express ; 10(3)2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38417162

RESUMO

Stroke is a neurological syndrome that usually causes a loss of voluntary control of lower/upper body movements, making it difficult for affected individuals to perform Activities of Daily Living (ADLs). Brain-Computer Interfaces (BCIs) combined with robotic systems, such as Motorized Mini Exercise Bikes (MMEB), have enabled the rehabilitation of people with disabilities by decoding their actions and executing a motor task. However, Electroencephalography (EEG)-based BCIs are affected by the presence of physiological and non-physiological artifacts. Thus, movement discrimination using EEG become challenging, even in pedaling tasks, which have not been well explored in the literature. In this study, Common Spatial Patterns (CSP)-based methods were proposed to classify pedaling motor tasks. To address this, Filter Bank Common Spatial Patterns (FBCSP) and Filter Bank Common Spatial-Spectral Patterns (FBCSSP) were implemented with different spatial filtering configurations by varying the time segment with different filter bank combinations for the three methods to decode pedaling tasks. An in-house EEG dataset during pedaling tasks was registered for 8 participants. As results, the best configuration corresponds to a filter bank with two filters (8-19 Hz and 19-30 Hz) using a time window between 1.5 and 2.5 s after the cue and implementing two spatial filters, which provide accuracy of approximately 0.81, False Positive Rates lower than 0.19, andKappaindex of 0.61. This work implies that EEG oscillatory patterns during pedaling can be accurately classified using machine learning. Therefore, our method can be applied in the rehabilitation context, such as MMEB-based BCIs, in the future.


Assuntos
Interfaces Cérebro-Computador , Acidente Vascular Cerebral , Humanos , Atividades Cotidianas , Movimento , Eletroencefalografia/métodos
3.
Biomed Phys Eng Express ; 9(4)2023 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-37321179

RESUMO

Motor Imagery (MI)-Brain Computer-Interfaces (BCI) illiteracy defines that not all subjects can achieve a good performance in MI-BCI systems due to different factors related to the fatigue, substance consumption, concentration, and experience in the use. To reduce the effects of lack of experience in the use of BCI systems (naïve users), this paper presents the implementation of three Deep Learning (DL) methods with the hypothesis that the performance of BCI systems could be improved compared with baseline methods in the evaluation of naïve BCI users. The methods proposed here are based on Convolutional Neural Network (CNN), Long Short-Term Memory (LSTM)/Bidirectional Long Short-Term Memory (BiLSTM), and a combination of CNN and LSTM used for upper limb MI signal discrimination on a dataset of 25 naïve BCI users. The results were compared with three widely used baseline methods based on the Common Spatial Pattern (CSP), Filter Bank Common Spatial Pattern (FBCSP), and Filter Bank Common Spatial-Spectral Pattern (FBCSSP), in different temporal window configurations. As results, the LSTM-BiLSTM-based approach presented the best performance, according to the evaluation metrics of Accuracy, F-score, Recall, Specificity, Precision, and ITR, with a mean performance of 80% (maximum 95%) and ITR of 10 bits/min using a temporal window of 1.5 s. The DL Methods represent a significant increase of 32% compared with the baseline methods (p< 0.05). Thus, with the outcomes of this study, it is expected to increase the controllability, usability, and reliability of the use of robotic devices in naïve BCI users.


Assuntos
Interfaces Cérebro-Computador , Aprendizado Profundo , Humanos , Imaginação , Reprodutibilidade dos Testes , Eletroencefalografia/métodos
4.
Proc Inst Mech Eng H ; 237(3): 327-335, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36974031

RESUMO

An emerging source of information to recognize individuals' characteristics are the walking pattern-related parameters. The elderly can be one of the populations that can benefit most from recognition-based applications, which may help to increase their possibilities of living independently at home. Approaches have been mostly focused on gait events' identification or assessment; nonetheless, such information can also be used to obtain seniors' characteristics that depend on physiological or environmental factors. These factors can be useful to provide a customized assistance based on contextual information. In this paper, we propose a method focused on seniors, to detect steps, and to recognize gender and type of shoes by using only the initial foot contact (IC) data obtained from inertial sensors during semi-controlled walking. Data were collected from 20 older adults who walked at self-speed in a natural environment. The method consists of first clustering the IC using k-means; then, a trained recurrent neural network recognizes gender, type of shoes, and the step phases (IC and other phases); to finally conduct step detection (SD) using a ruled-based method. The method recognizes gender and the type of shoes with an accuracy of 93% and 83.07%, respectively, whereas there were not misrecognitions of the step phases. SD achieved a mean absolute percentage error equal to 0.64%. The good results show that the method is appropriate for users' characteristics recognition applications without depending on assumptions based on individualities. Likewise, the method can be useful to monitor physical activity or systems aimed to keep safe older adults.


Assuntos
Marcha , Sapatos , Humanos , Idoso , Marcha/fisiologia , Caminhada/fisiologia ,
5.
Rev. MED ; 18(1): 58-66, ene.-jun. 2010.
Artigo em Espanhol | LILACS | ID: lil-670841

RESUMO

El dolor orofacial en sus fases aguda y crónica, sea somático de etiología neuropática, o asociado a condiciones psicológicas, tiene una alta prevalencia en nuestro medio. Múltiples opciones terapéuticas de tipo farmacológico se convierten en la primera línea de tratamiento y la correcta elección depende de la patología subyacente. Esta decisión no siempre se facilita debido a que no existe unidad en cuanto a los criterios diagnósticos para su clasificación. Teniendo en cuenta la multiplicidad de opciones, el objetivo de la presente revisión es analizar los tratamientos descritos en la literatura científica actual, con el propósito de brindar elementos que faciliten tomar una decisión certera en cada caso específico de dolor orofacial...


Orofacial pain in its acute and chronic phases, either of somatic etiology or associated with psychological conditions is of highly prevalence. Multiple pharmacological therapies are the first line of treatment, and the correct choice depends on the underlying pathology. This decision is not always easy because there is not unity in the diagnostic criteria used for its classification. Given the multiplicity of options, the objective of this review is to analyze the treatments described in the current scientific literature, in order to provide the elements to make an accurate decision in each specific case of orofacial pain...


A dor orofacial nas fases aguda e crônica, seja somática de etiologia neuropática ou associada a condições psicológicas, é altamente prevalente em nosso meio. Várias opções terapêuticas de tratamento farmacológico se tornarem a primeira linha de tratamento e a escolha correta depende da patologia de base. Esta decisão nem sempre é fácil porque não há nenhuma unidade em termos de critérios diagnósticos para a classificação. Dada a multiplicidade de opções, o objetivo desta revisão é analisar os tratamentos descritos na literatura científica atual, a fim de fornecer elementos que facilitem tomar uma decisão correta em cada caso específico da dor orofacial...


Assuntos
Humanos , Dor Crônica , Dor Facial , Neuralgia do Trigêmeo
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