Motor imagery classification using sparse representations: an exploratory study.

The non-stationary nature of the EEG signal poses challenges for the classification of motor imagery. sparse representation classification (SRC) appears as an alternative for classification of untrained conditions and, therefore, useful in motor imagery. Empirical mode decomposition (EMD) deals with signals of this nature and appears at the rear of the classification, supporting the generation of features. In this work we evaluate the combination of these methods in a multiclass classification problem, comparing them with a conventional method in order to determine if their performance is regular. For comparison with SRC we use multilayer perceptron (MLP). We also evaluated a hybrid approach for classification of sparse representations with MLP (RSMLP). For comparison with EMD we used filtering by frequency bands. Feature selection methods were used to select the most significant ones, specifically Random Forest and Particle Swarm Optimization. Finally, we used data augmentation to get a more voluminous base. Regarding the first dataset, we observed that the classifiers that use sparse representation have results equivalent to each other, but they outperform the conventional MLP model. SRC and SRMLP achieve an average accuracy of [Formula: see text] and [Formula: see text] respectively while the MLP is [Formula: see text], representing a gain between [Formula: see text] and [Formula: see text]. The use of EMD in relation to other feature processing techniques is not superior. However, EMD does not influence negatively, there is an opportunity for improvement. Finally, the use of data augmentation proved to be important to obtain relevant results. In the second dataset, we did not observe the same results. Models based on sparse representation (SRC, SRMLP, etc.) have on average a performance close to other conventional models, but without surpassing them. The best sparse models achieve an average accuracy of [Formula: see text] among the subjects in the base, while other model reach [Formula: see text]. The improvement of self-adaptive mechanisms that respond efficiently to the user's context is a good way to achieve improvements in motor imagery applications. However, other scenarios should be investigated, since the advantage of these methods was not proven in all datasets studied. There is still room for improvement, such as optimizing the dictionary of sparse representation in the context of motor imagery. Investing efforts in synthetically increasing the training base has also proved important to reduce the costs of this group of applications.

Viability of gait speed test in hospitalized elderly patients.

OBJECTIVE: The gait speed test (GST) is a physical test that can predict falls and aid in the diagnosis of sarcopenia in the elderly. However, to our knowledge, there have been no studies evaluating its reproducibility in hospitalized elderly patients. The objective of this study was to evaluate the safety and reproducibility of the six-meter GST (6GST) in hospitalized elderly patients. METHODS: This repeated measures study involved hospitalized elderly patients (≥ 60 years of age) who underwent the 6GST by the fifth day of hospitalization, were able to walk without assistance, and presented no signs of dyspnea or pain that would prevent them from performing the test. The 6GST was performed three times in sequence, with a rest period between each test, in a level corridor. Gait speed was measured in meters/second. Reproducibility was assessed by comparing the means, intraclass correlation coefficients (ICCs) and Bland-Altman plots. RESULTS: We evaluated 110 elderly patients in a total of 330 tests. All participants completed all of the tests. The comparisons between the speeds obtained during the three tests showed high ICCs and a low mean bias (Bland-Altman plots). The correlation and accuracy were greatest when the mean maximum speed was compared with that obtained in the third test (1.26 ± 0.44 m/s vs. 1.22 ± 0.44 m/s; ICC = 0.99; p = 0.001; mean bias = 0.04; and limits of agreement = -0.27 to 0.15). CONCLUSIONS: The 6GST was proven to be safe and to have good reproducibility in this sample of hospitalized elderly patients. The third measurement seems to correspond to the maximum speed, since the first two measurements underestimated the actual performance. OBJETIVO: O teste de velocidade de marcha (TVM) é um teste físico que pode predizer quedas e auxiliar no diagnóstico de sarcopenia em idosos da comunidade. Entretanto, pelo que sabemos, não há estudos que avaliaram sua reprodutibilidade em idosos hospitalizados. O objetivo deste estudo foi avaliar a segurança e a reprodutibilidade do TVM de seis metros (TVM6) em idosos hospitalizados. MÉTODOS: Estudo com medidas repetidas envolvendo idosos hospitalizados (idade ≥ 60 anos) que realizaram o TVM6 até o quinto dia de hospitalização, sendo capazes de andar sem auxílio e não apresentando dispneia ou dor que os incapacitasse para a realização dos testes. O TVM6 foi realizado sequencialmente três vezes, com período de descanso, em um corredor plano, e a velocidade de marcha foi calculada em metros/segundo. A reprodutibilidade foi avaliada pela comparação das médias, coeficientes de correlação intraclasse (CCI) e disposições gráficas de Bland-Altman. RESULTADOS: Foram avaliados 110 idosos avaliados com um total de 330 testes. Todos os participantes completaram todos os testes. As comparações entre as velocidades obtidas nos três testes realizados indicaram CCIs elevados e viés médio baixo pela disposição gráfica de Bland-Altman. Em relação à maior velocidade aferida, a correlação e a precisão foram maiores quando comparadas à obtida no terceiro teste (1,26 ± 0,44 m/s vs. 1,22 ± 0,44 m/s; CCI = 0,99; p = 0,001; viés médio = 0,04; e limites de concordância = -0,27 a 0,15). CONCLUSÕES: O TVM6 mostrou-se seguro e teve boa reprodutibilidade nessa amostra de idosos hospitalizados. A terceira aferição parece corresponder à velocidade máxima, já que duas primeiras subestimaram o desempenho real.

Viability of gait speed test in hospitalized elderly patients / Viabilidade do teste de velocidade de marcha em idosos hospitalizados

ABSTRACT Objective: The gait speed test (GST) is a physical test that can predict falls and aid in the diagnosis of sarcopenia in the elderly. However, to our knowledge, there have been no studies evaluating its reproducibility in hospitalized elderly patients. The objective of this study was to evaluate the safety and reproducibility of the six-meter GST (6GST) in hospitalized elderly patients. Methods: This repeated measures study involved hospitalized elderly patients (≥ 60 years of age) who underwent the 6GST by the fifth day of hospitalization, were able to walk without assistance, and presented no signs of dyspnea or pain that would prevent them from performing the test. The 6GST was performed three times in sequence, with a rest period between each test, in a level corridor. Gait speed was measured in meters/second. Reproducibility was assessed by comparing the means, intraclass correlation coefficients (ICCs) and Bland-Altman plots. Results: We evaluated 110 elderly patients in a total of 330 tests. All participants completed all of the tests. The comparisons between the speeds obtained during the three tests showed high ICCs and a low mean bias (Bland-Altman plots). The correlation and accuracy were greatest when the mean maximum speed was compared with that obtained in the third test (1.26 ± 0.44 m/s vs. 1.22 ± 0.44 m/s; ICC = 0.99; p = 0.001; mean bias = 0.04; and limits of agreement = −0.27 to 0.15). Conclusions: The 6GST was proven to be safe and to have good reproducibility in this sample of hospitalized elderly patients. The third measurement seems to correspond to the maximum speed, since the first two measurements underestimated the actual performance.

RESUMO Objetivo: O teste de velocidade de marcha (TVM) é um teste físico que pode predizer quedas e auxiliar no diagnóstico de sarcopenia em idosos da comunidade. Entretanto, pelo que sabemos, não há estudos que avaliaram sua reprodutibilidade em idosos hospitalizados. O objetivo deste estudo foi avaliar a segurança e a reprodutibilidade do TVM de seis metros (TVM6) em idosos hospitalizados. Métodos: Estudo com medidas repetidas envolvendo idosos hospitalizados (idade ≥ 60 anos) que realizaram o TVM6 até o quinto dia de hospitalização, sendo capazes de andar sem auxílio e não apresentando dispneia ou dor que os incapacitasse para a realização dos testes. O TVM6 foi realizado sequencialmente três vezes, com período de descanso, em um corredor plano, e a velocidade de marcha foi calculada em metros/segundo. A reprodutibilidade foi avaliada pela comparação das médias, coeficientes de correlação intraclasse (CCI) e disposições gráficas de Bland-Altman. Resultados: Foram avaliados 110 idosos avaliados com um total de 330 testes. Todos os participantes completaram todos os testes. As comparações entre as velocidades obtidas nos três testes realizados indicaram CCIs elevados e viés médio baixo pela disposição gráfica de Bland-Altman. Em relação à maior velocidade aferida, a correlação e a precisão foram maiores quando comparadas à obtida no terceiro teste (1,26 ± 0,44 m/s vs. 1,22 ± 0,44 m/s; CCI = 0,99; p = 0,001; viés médio = 0,04; e limites de concordância = −0,27 a 0,15). Conclusões: O TVM6 mostrou-se seguro e teve boa reprodutibilidade nessa amostra de idosos hospitalizados. A terceira aferição parece corresponder à velocidade máxima, já que duas primeiras subestimaram o desempenho real.

Treinamento muscular inspiratório e desmame ventilatório de paciente com síndrome pós-pólio / Inspiratory muscle training and ventilation weaning in patient with post-polio syndrome

A síndrome pós-pólio (SPP) é a recidiva dos sintomas da poliomielite anterior aguda (PAA), e o quadro é caracterizado por fraqueza muscular flácida assimétrica, com frequente comprometimento respiratório e de deglutição, além dos distúrbios de sono. O presente estudo relata o caso de uma paciente idosa, em ventilação mecânica domiciliar. Investiu-se no treinamento muscular inspiratório (TMI) com Powerbreathe® por 30 repetições por 2 vezes ao dia, durante 4 semanas, associado a um programa de exercícios físicos. Tal estratégia apresentou como desfecho o desmame da ventilação mecânica (VM), assim como melhora concomitante na Pimax e Mensuração de Independência Funcional (MIF), retornando ao final deste curto programa de reabilitação a realizar atividades laborais em domicílio. O presente relato de caso conclui que o emprego da TMI em pacientes com SPP pode ser uma estratégia promissora para o desmame ventilatório. (AU)

The post-polio syndrome (PPS) is the recurrence of the symptoms of acute anterior poliomyelitis (AAP), and characterized by asymmetrical flaccid muscle weakness, with respiratory and swallowing impairment, in addition to sleep disorders. The present study reports the case of an elderly patient in home mechanical ventilation. We invested in inspiratory muscle training (IMT) ® with Powerbreathe for 30 repetitions, twice daily, during 4 weeks, associated with a program of physical exercise. This strategy showed weaning from mechanical ventilation (MV), as well as a concomitant improvement in Pimax and Functional Independence Measure (FIM), returning at the end of this short rehabilitation program to perform work activities at home. This case study concludes that the use of IMT in patients with PPS may be a promising strategy for weaning. (AU)