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1.
PLoS One ; 15(1): e0218977, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31978115

RESUMO

Tying the hands behind the back has detrimental effects on sensorimotor perceptual tasks. Here we provide evidence that beta band oscillatory activity in a resting state condition might play a crucial role in such detrimental effects. EEG activity at rest was measured from thirty young participants (mean age = 24.03) in two different body posture conditions. In one condition participants were required to keep their hands freely resting on the table. In the other condition, participants' hands were tied behind their back. Increased beta power was observed in the left inferior frontal gyrus during the tied hands condition compared to the free hands condition. A control experiment ruled out alternative explanations for observed change in beta power, including muscle tension. Our findings provide new insights on how body postural manipulations impact on perceptual tasks and brain activity.


Assuntos
Encéfalo/fisiologia , Fenômenos Fisiológicos Musculoesqueléticos , Equilíbrio Postural/fisiologia , Córtex Sensório-Motor/fisiologia , Adulto , Mapeamento Encefálico , Eletroencefalografia , Feminino , Mãos/fisiologia , Humanos , Masculino , Contração Muscular/fisiologia , Descanso/fisiologia , Couro Cabeludo/fisiologia , Visão Ocular/fisiologia , Adulto Jovem
2.
J Sports Sci ; 38(1): 46-52, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31658889

RESUMO

The purpose of this study was to determine the influence of pelvis and torso angular jerk on a performance indicator of hitting, specifically hand velocity. Eighteen softball athletes were analysed (20.3 ± 1.6 years; 164.9 ± 24.9 cm; 74.4 ± 14.0 kg). Participants were instructed to execute 3 maximum effort swings off a stationary tee at the middle "strike-zone" location. Angular jerk data were analysed during the acceleration phase of the swing, the time between foot contact and ball contact. Quadratic regression analyses were conducted to examine the relationship of minimal pelvis angular jerk and minimal torso angular jerk to angular hand velocity at ball contact. No significant relationship was found between pelvis angular jerk and angular hand velocity at ball contact (r = 0.192, p = 0.754). The curvilinear regression model for pelvis angular jerk produced: R2 = 0.037; F (2, 17) = 0.288; p = 0.754. Lack of significant findings suggests a relationship between jerk and angular hand velocity does not exist within female softball hitting. Future research should investigate the timing of minimal jerk through the acceleration phase as a predictor of angular hand velocity, rather than the value of jerk itself.


Assuntos
Desempenho Atlético/fisiologia , Beisebol/fisiologia , Mãos/fisiologia , Pelve/fisiologia , Tronco/fisiologia , Aceleração , Fenômenos Biomecânicos , Feminino , Humanos , Destreza Motora/fisiologia , Movimento/fisiologia , Estudos de Tempo e Movimento , Adulto Jovem
3.
Diving Hyperb Med ; 49(4): 266-275, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31828745

RESUMO

INTRODUCTION: The purpose of the study was to evaluate the thermal protection provided by a 2-3 mm surfing wet suit during at least two hours of fin diving in shallow water with a temperature of 16-20°C. We examined the effect of wearing the suit while diving in cold water on cognitive performance, muscle strength, and hand motor function. METHODS: Subjects were six male well-trained rebreather divers, 19-23 years old, acclimatised to cold. They attended the laboratory on three separate occasions, when we conducted the experiment at one of three temperatures, 16, 18, and 20°C. Core temperature (gastrointestinal system), skin temperature, oxygen consumption, and cold perception were evaluated during the test. Before and immediately after the dives, subjects performed a series of cognitive, manual dexterity, and muscle strength tests. RESULTS: Core temperature decreased by 0.35-0.81°C over the two hours at all three water temperatures. No subject reached a core temperature below 35°C. The decrease in upper body skin temperature during the two hour dive ranged between 5.97 and 8.41°C (P < 0.05). Two hours diving in 16-20°C water resulted in a significant increase in the time taken to perform the task of unlinking and reassembling four shackles (∼30% longer, P < 0.05). No effect was found on the cognitive or muscle strength tests. CONCLUSIONS: A 2-3 mm wet suit provides adequate thermal protection in trained and cold-acclimatised young males engaged in active diving in shallow water with a temperature of 16°C and above.


Assuntos
Cognição/fisiologia , Temperatura Baixa , Mergulho , Força Muscular/fisiologia , Roupa de Proteção , Regulação da Temperatura Corporal , Mergulho/fisiologia , Mãos/fisiologia , Força da Mão/fisiologia , Humanos , Masculino , Destreza Motora/fisiologia , Consumo de Oxigênio , Temperatura Ambiente , Água
4.
PLoS One ; 14(12): e0219333, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31887218

RESUMO

BACKGROUND: Successful hand-object interactions require precise hand-eye coordination with continual movement adjustments. Quantitative measurement of this visuomotor behaviour could provide valuable insight into upper limb impairments. The Gaze and Movement Assessment (GaMA) was developed to provide protocols for simultaneous motion capture and eye tracking during the administration of two functional tasks, along with data analysis methods to generate standard measures of visuomotor behaviour. The objective of this study was to investigate the reproducibility of the GaMA protocol across two independent groups of non-disabled participants, with different raters using different motion capture and eye tracking technology. METHODS: Twenty non-disabled adults performed the Pasta Box Task and the Cup Transfer Task. Upper body and eye movements were recorded using motion capture and eye tracking, respectively. Measures of hand movement, angular joint kinematics, and eye gaze were compared to those from a different sample of twenty non-disabled adults who had previously performed the same protocol with different technology, rater and site. RESULTS: Participants took longer to perform the tasks versus those from the earlier study, although the relative time of each movement phase was similar. Measures that were dissimilar between the groups included hand distances travelled, hand trajectories, number of movement units, eye latencies, and peak angular velocities. Similarities included all hand velocity and grip aperture measures, eye fixations, and most peak joint angle and range of motion measures. DISCUSSION: The reproducibility of GaMA was confirmed by this study, despite a few differences introduced by learning effects, task demonstration variation, and limitations of the kinematic model. GaMA accurately quantifies the typical behaviours of a non-disabled population, producing precise quantitative measures of hand function, trunk and angular joint kinematics, and associated visuomotor behaviour. This work advances the consideration for use of GaMA in populations with upper limb sensorimotor impairment.


Assuntos
Medições dos Movimentos Oculares/normas , Movimentos Oculares/fisiologia , Mãos/fisiologia , Adulto , Fenômenos Biomecânicos/fisiologia , Medições dos Movimentos Oculares/instrumentação , Feminino , Fixação Ocular/fisiologia , Força da Mão/fisiologia , Humanos , Masculino , Movimento/fisiologia , Desempenho Psicomotor , Amplitude de Movimento Articular/fisiologia , Reprodutibilidade dos Testes , Extremidade Superior/fisiologia
5.
Atten Percept Psychophys ; 81(7): 2538-2557, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31691102

RESUMO

From an embodiment perspective, action and cognition influence each other constantly. This interaction has been utilized in mouse-tracking studies to infer cognitive states from movements, assuming a continuous manifestation of cognitive processing into movement. However, it is mostly unknown how this manifestation is affected by the variety of possible design choices in mouse-tracking paradigms. Here we studied how three design factors impact the manifestation of cognition into movement in a Simon task with mouse tracking. We varied the response selection (i.e., with or without clicking), the ratio between hand and mouse cursor movement, and the location of the response boxes. The results show that all design factors can blur or even prevent the manifestation of cognition into movement, as reflected by a reduction in movement consistency and action dynamics, as well as by the adoption of unsuitable movement strategies. We conclude that deliberate and careful design choices in mouse-tracking experiments are crucial to ensuring a continuous manifestation of cognition in movement. We discuss the importance of developing a standard practice in the design of mouse-tracking experiments.


Assuntos
Cognição/fisiologia , Percepção de Movimento/fisiologia , Movimento/fisiologia , Estimulação Luminosa/métodos , Tempo de Reação/fisiologia , Adolescente , Adulto , Feminino , Mãos/fisiologia , Humanos , Masculino , Adulto Jovem
6.
Sensors (Basel) ; 19(20)2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31615162

RESUMO

Feature extraction, as an important method for extracting useful information from surfaceelectromyography (SEMG), can significantly improve pattern recognition accuracy. Time andfrequency analysis methods have been widely used for feature extraction, but these methods analyzeSEMG signals only from the time or frequency domain. Recent studies have shown that featureextraction based on time-frequency analysis methods can extract more useful information fromSEMG signals. This paper proposes a novel time-frequency analysis method based on the Stockwelltransform (S-transform) to improve hand movement recognition accuracy from forearm SEMGsignals. First, the time-frequency analysis method, S-transform, is used for extracting a feature vectorfrom forearm SEMG signals. Second, to reduce the amount of calculations and improve the runningspeed of the classifier, principal component analysis (PCA) is used for dimensionality reduction of thefeature vector. Finally, an artificial neural network (ANN)-based multilayer perceptron (MLP) is usedfor recognizing hand movements. Experimental results show that the proposed feature extractionbased on the S-transform analysis method can improve the class separability and hand movementrecognition accuracy compared with wavelet transform and power spectral density methods.


Assuntos
Algoritmos , Eletromiografia , Mãos/fisiologia , Movimento/fisiologia , Reconhecimento Automatizado de Padrão , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Ondaletas
7.
Sensors (Basel) ; 19(20)2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31623249

RESUMO

To improve the accuracy and robustness of hand-eye calibration, a hand-eye calibration method based on Schur matric decomposition is proposed in this paper. The accuracy of these methods strongly depends on the quality of observation data. Therefore, preprocessing observation data is essential. As with traditional two-step hand-eye calibration methods, we first solve the rotation parameters and then the translation vector can be immediately determined. A general solution was obtained from one observation through Schur matric decomposition and then the degrees of freedom were decreased from three to two. Observation data preprocessing is one of the basic unresolved problems with hand-eye calibration methods. A discriminant equation to delete outliers was deduced based on Schur matric decomposition. Finally, the basic problem of observation data preprocessing was solved using outlier detection, which significantly improved robustness. The proposed method was validated by both simulations and experiments. The results show that the prediction error of rotation and translation was 0.06 arcmin and 1.01 mm respectively, and the proposed method performed much better in outlier detection. A minimal configuration for the unique solution was proven from a new perspective.


Assuntos
Olho , Mãos/fisiologia , Fenômenos Fisiológicos Oculares , Robótica/tendências , Algoritmos , Calibragem , Humanos , Processamento de Imagem Assistida por Computador , Modelos Teóricos
8.
Elife ; 82019 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-31524600

RESUMO

Motor fatigability emerges when demanding tasks are executed over an extended period of time. Here, we used repetitive low-force movements that cause a gradual reduction in movement speed (or 'motor slowing') to study the central component of fatigability in healthy adults. We show that motor slowing is associated with a gradual increase of net excitability in the motor network and, specifically, in primary motor cortex (M1), which results from overall disinhibition. Importantly, we link performance decrements to a breakdown of surround inhibition in M1, which is associated with high coactivation of antagonistic muscle groups. This is consistent with the model that a loss of inhibitory control might broaden the tuning of population vectors such that movement patterns become more variable, ill-timed and effortful. We propose that the release of inhibition in M1 is an important mechanism underpinning motor fatigability and, potentially, also pathological fatigue as frequently observed in patients with brain disorders.


Assuntos
Fadiga , Mãos/fisiologia , Movimento , Adulto , Eletroencefalografia , Feminino , Voluntários Saudáveis , Humanos , Imagem por Ressonância Magnética , Masculino , Modelos Neurológicos , Córtex Motor/fisiologia , Adulto Jovem
9.
Gait Posture ; 74: 135-141, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31522106

RESUMO

INTRODUCTION: The main role of the upper limb is to position the hand in order to carry out varied activities requiring coordinated multi-joint movement, which requires mobility and stability at the glenohumeral joint. This is made possible by the interaction between active and passive structures as well as the integration of information coming from multiple systems. This interaction can be compromised by factors such as muscle fatigue and lack of visual feedback, leading to decreased performance. Several studies have investigated their isolated effect without looking at their combined effect. OBJECTIVE: To measure the specific and the combined effects of shoulder muscles fatigue and of lack of visual feedback on shoulder motor control during a reaching task with the arm in an elevated position. METHODS: 60 healthy participants were randomly assigned to one of four experimental groups: 1) control with visual feedback; 2) control without visual feedback; 3) fatigue with visual feedback; 4) fatigue without visual feedback. Subjects had to perform 10 trials of a reaching task in the KINARM robotic arm. Kinematic variables of interest were time taken to complete the task, final error, initial angle of deviation and area under curve. Non-parametric ANOVAs were used. RESULTS: Analyses showed that there were statistically significant differences (p < 0,01) for the time taken to complete the task (1.15 s compared to 0.70 s), the area under the curve (0.015m2 compared to 0.009m2) and the final error (0.025 m compared to 0,011 m) between those who had visual feedback and those who did not. No statistically significant fatigue or feedback X fatigue interaction effects were found for all kinematic variables. CONCLUSION: Findings show that lack of visual feedback had an impact on the reaching task performance while fatigue did not. In addition, fatigue did not increase the effect of the lack of visual feedback.


Assuntos
Retroalimentação Sensorial/fisiologia , Movimento/fisiologia , Fadiga Muscular/fisiologia , Músculo Esquelético/fisiologia , Ombro/fisiologia , Percepção Visual/fisiologia , Adulto , Análise de Variância , Fenômenos Biomecânicos , Feminino , Mãos/fisiologia , Humanos , Masculino , Amplitude de Movimento Articular , Análise e Desempenho de Tarefas , Adulto Jovem
10.
Ann Agric Environ Med ; 26(3): 472-478, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31559806

RESUMO

INTRODUCTION: Winter pruning is a cultivation practice necessary for maintaining the balance between the vegetative and the productive activity of plants and requires many working days using hand scissors. This operation involves the subjects carrying out a series of gestures that are repeated with considerable frequency, which are all musculo-skeletal disorders risk factors (MSDs) for the hand-wrist area. OBJECTIVE: The aim of this study was to investigate the forces applied to pruning tools. MATERIAL AND METHODS: Using a sensor matrix, peak and average forces were measured which are exerted while cutting branches of 3 different diameters, from 5 wine-grape cultivars. Samples were tested on 8 participants using sensored scissors to record, in 6 hand areas, the forces necessary to cut. RESULTS: Results showed that while cutting, the factors which can impact the force employed (peak and average forces) by the subjects are branch diameter and percentage of branch humidity. Cut duration was inversely related to the size of the subject's hand. The middle finger area of the hand recorded the highest force average and peak levels, while the hand region least affected during the cuts was the farthest from the thumb. CONCLUSIONS: The study enabled the highlighting of which factors influence the forces employed by the operator while cutting grape branches, and to identify the hand regions where muscle activation is at its most. These findings can be relevant in preventing MSDs. Further studies need to be conducted with a larger number of subjects.


Assuntos
Agricultura/instrumentação , Mãos/fisiologia , Adulto , Fenômenos Biomecânicos , Força da Mão , Humanos , Masculino , Músculo Esquelético/química , Músculo Esquelético/fisiologia , Projetos Piloto
11.
J Electromyogr Kinesiol ; 49: 102349, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31476613

RESUMO

OBJECTIVE: Near-fibre (NF) jiggle is one method of measuring the shape variability of motor unit potentials (MUPs) from successive firings during voluntary contractions. MUP shape variability has been associated with neuromuscular stability and health. The purpose of this study was to analyze the test-retest reliability of NF jiggle in the ulnar nerve innervated intrinsic hand muscles of healthy subjects. METHODS: Twenty healthy adult were tested (Mean age = 23.2 ±â€¯1.9; 8 females). Measurements of NF jiggle were assessed with a standard concentric needle during mild-moderate contractions from the first dorsal interosseous (FDI), the abductor digiti minimi (ADM), and the forth dorsal interosseous (4DI) muscles. Test-retest reliability were evaluated using intraclass-correlation coefficient (ICC). RESULTS: NF jiggle showed good test-retest reliability in the FDI, ADM and 4DI muscles with ICC values of 0.86, 0.85, and 0.87, respectively. The SEM for the FDI, ADM, and 4DI were 1.9%, 2.1%, and 2.5%. Finally, the MDC of the FDI, ADM and 4DI were 4.4%, 5.0%, and 7.1%. CONCLUSION: To date, this is the first investigation to explore NF jiggle in the intrinsic hand muscles. NF Jiggle demonstrates good test-retest reliability coefficients and with low measurement error.


Assuntos
Eletromiografia/métodos , Músculo Esquelético/fisiologia , Nervo Ulnar/fisiologia , Adulto , Eletromiografia/normas , Feminino , Mãos/inervação , Mãos/fisiologia , Humanos , Masculino , Músculo Esquelético/inervação , Reprodutibilidade dos Testes
12.
Sensors (Basel) ; 19(18)2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31487894

RESUMO

We propose an efficient hand gesture recognition (HGR) algorithm, which can cope with time-dependent data from an inertial measurement unit (IMU) sensor and support real-time learning for various human-machine interface (HMI) applications. Although the data extracted from IMU sensors are time-dependent, most existing HGR algorithms do not consider this characteristic, which results in the degradation of recognition performance. Because the dynamic time warping (DTW) technique considers the time-dependent characteristic of IMU sensor data, the recognition performance of DTW-based algorithms is better than that of others. However, the DTW technique requires a very complex learning algorithm, which makes it difficult to support real-time learning. To solve this issue, the proposed HGR algorithm is based on a restricted column energy (RCE) neural network, which has a very simple learning scheme in which neurons are activated when necessary. By replacing the metric calculation of the RCE neural network with DTW distance, the proposed algorithm exhibits superior recognition performance for time-dependent sensor data while supporting real-time learning. Our verification results on a field-programmable gate array (FPGA)-based test platform show that the proposed HGR algorithm can achieve a recognition accuracy of 98.6% and supports real-time learning and recognition at an operating frequency of 150 MHz.


Assuntos
Técnicas Biossensoriais , Gestos , Mãos/fisiologia , Aprendizado de Máquina , Algoritmos , Humanos , Interface Usuário-Computador
13.
Sensors (Basel) ; 19(18)2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31509987

RESUMO

In this paper, a new control-centric approach is introduced to model the characteristics of flex sensors on a goniometric glove, which is designed to capture the user hand gesture that can be used to wirelessly control a bionic hand. The main technique employs the inverse dynamic model strategy along with a black-box identification for the compensator design, which is aimed to provide an approximate linear mapping between the raw sensor output and the dynamic finger goniometry. To smoothly recover the goniometry on the bionic hand's side during the wireless transmission, the compensator is restructured into a Hammerstein-Wiener model, which consists of a linear dynamic system and two static nonlinearities. A series of real-time experiments involving several hand gestures have been conducted to analyze the performance of the proposed method. The associated temporal and spatial gesture data from both the glove and the bionic hand are recorded, and the performance is evaluated in terms of the integral of absolute error between the glove's and the bionic hand's dynamic goniometry. The proposed method is also compared with the raw sensor data, which has been preliminarily calibrated with the finger goniometry, and the Wiener model, which is based on the initial inverse dynamic design strategy. Experimental results with several trials for each gesture show that a great improvement is obtained via the Hammerstein-Wiener compensator approach where the resulting average errors are significantly smaller than the other two methods. This concludes that the proposed strategy can remarkably improve the dynamic goniometry of the glove, and thus provides a smooth human-robot collaboration with the bionic hand.


Assuntos
Algoritmos , Artrometria Articular , Biônica , Mãos/fisiologia , Fenômenos Biomecânicos , Humanos
14.
Exp Brain Res ; 237(10): 2585-2594, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31372687

RESUMO

Grip force has been studied widely in a variety of interaction and movement tasks, however, not much is known about the timing of the grip force control in preparation for interaction with objects. For example, it is unknown whether and how the temporal preparation for a collision is related to (the prediction of) the impact load. To study this question, we examined the anticipative timing of the grip force in preparation for impact loads. We designed a collision task with different types of load forces in a controlled virtual environment. Participants interacted with a robotic device (KINARM, BKIN Technologies, Kingston) whose handles were equipped with force sensors which the participants held in precision grip. Representations of the hand and objects were visually projected on a virtual reality display and forces were applied onto the participant's hand to simulate a collision with the virtual objects. The collisions were alternating between the two hands to allow transfer and learning between the hands. The results show that there is immediate transfer of object information between the two hands, since the grip force levels are (almost) fully adjusted after one collision with the opposite hand. The results also show that the grip force levels are nicely adjusted based on the mass and stiffness of the object. Surprisingly, the temporal onset of the grip force build up did not depend on the impact load, so that participants avoid slippage by adjusting the other grip force characteristics (e.g., grip force level and rate of change), therefore considering these self-imposed timing constraints. With the use of catch trials, for which no impact occurred, we further analyzed the temporal profile of the grip force. The catch trial data showed that the timing of the grip force peak is also independent of the impact load and its timing, which suggests a time-locked planning of the complete grip force profile.


Assuntos
Comportamento/fisiologia , Força da Mão/fisiologia , Fenômenos Mecânicos , Movimento/fisiologia , Adulto , Feminino , Mãos/fisiologia , Humanos , Masculino , Análise e Desempenho de Tarefas , Suporte de Carga/fisiologia
15.
Med Biol Eng Comput ; 57(10): 2179-2201, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31388900

RESUMO

It is of great importance to effectively process and interpret surface electromyogram (sEMG) signals to actuate a robotic and prosthetic exoskeleton hand needed by hand amputees. In this paper, we have proposed a cepstrum analysis-based method for classification of basic hand movement sEMG signals. Cepstral analysis technique primarily used for analyzing acoustic and seismological signals is effectively exploited to extract features of time-domain sEMG signals by computing mel-frequency cepstral coefficients (MFCCs). The extracted feature vector consisting of MFCCs is then forwarded to feed a generalized regression neural network (GRNN) so as to classify basic hand movements. The proposed method has been tested on sEMG for Basic Hand movements Data Set and achieved an average accuracy rate of 99.34% for the five individual subjects and an overall mean accuracy rate of 99.23% for the collective (mixed) dataset. The experimental results demonstrate that the proposed method surpasses most of the previous studies in point of classification accuracy. Discrimination ability of the cepstral features exploited in this study is quantified using Kruskal-Wallis statistical test. Evidenced by the experimental results, this study explores and establishes applicability and efficacy of cepstrum-based features in classifying sEMG signals of hand movements. Owing to the non-iterative training nature of the artificial neural network type adopted in the study, the proposed method does not demand much time to build up the model in the training phase. Graphical abstract.


Assuntos
Algoritmos , Eletromiografia , Mãos/fisiologia , Movimento/fisiologia , Processamento de Sinais Assistido por Computador , Feminino , Humanos , Masculino , Análise de Componente Principal
16.
Cogn Process ; 20(4): 507-513, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31385142

RESUMO

Due to movement automatization, the engagement of high-order cognitive processing during the motor execution of a task is expected to decrease over repetitions and practice. In this study, we assessed single session changes in the prefrontal hemodynamic signals in response to training a piano chord progression in an ecological experimental setting. We acquired functional near-infrared spectroscopy signals from 15 subjects without any previous experience on playing keyboard instruments. Our findings were that oxygenated hemoglobin changes at orbitofrontal cortex followed an inverted U-shaped curve over task execution, while the subjects' performance presented a steady slope. These results suggest an initial executive function engagement followed by facilitation of motor execution over time.


Assuntos
Mãos/fisiologia , Hemodinâmica/fisiologia , Música/psicologia , Córtex Pré-Frontal/fisiologia , Adulto , Função Executiva/fisiologia , Feminino , Humanos , Masculino , Movimento/fisiologia , Oxiemoglobinas , Espectroscopia de Luz Próxima ao Infravermelho
17.
IEEE Int Conf Rehabil Robot ; 2019: 65-70, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374608

RESUMO

In this paper, we present the new personalized 3D printed soft robotic hand for providing rehabilitation training and daily activities assistance to stroke survivors. The Soft-Elastic Composite Actuator (SECA) on the robotic hand is direct 3D printed to accommodate with different finger sizes. Flexion and extension can be actively facilitated on the SECA using the same pressurizing source. Iterative learning model predictive control (ILMPC) method is used to be the control algorithm of SECA. At 160 kPa of maximum input pressure, results show that the actuator bending angles can reach to 137 °, and tip output force can also reach to 2.45 N. Multiple 3D printed SECAs are integrated to a 3D printed hand base and then to be worn on stroke survivors. Two stroke survivors are recruited to evaluate the intention-based rehabilitation training with the 3D printed soft robotic hand, which improvement of their hand function can be observed on performing some daily tasks such as grasping a coin.


Assuntos
Mãos/fisiologia , Robótica/instrumentação , Reabilitação do Acidente Vascular Cerebral/instrumentação , Algoritmos , Desenho de Equipamento , Exoesqueleto Energizado , Força da Mão , Humanos , Impressão Tridimensional , Amplitude de Movimento Articular
18.
IEEE Int Conf Rehabil Robot ; 2019: 101-107, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374614

RESUMO

Assessing proprioception is important for understanding and treating sensorimotor impairments. Many daily tasks require bimanual manipulation of objects, but state of the art methods for the assessment of proprioception are far away from bimanual activities, and instead evaluate sensorimotor integrity in oversimplified and often unimanual goal-directed tasks. Here, we developed a new device and method to assess proprioception and force production by simulating a realistic bimanual behavior. Twelve healthy participants held a physically coupled object - a sensorized box - and matched target orientations about the three principal axes without and with added weights. Our preliminary findings indicate that bimanual proprioception during orientation matching depends on the axis of rotation. For example, in rotations about the lateral axis of the body, underestimation and overestimation of the target angle depends on its orientation in a body-centered reference frame: participants tended to underestimate targets that required rotation far away from the body and overestimated angles that required rotation towards the body. We also found that for the same rotation axis, the larger were the rotations, the higher was the force applied. Moreover, we also found that fatigue causes undershoot in orientation matching. In the future, this tool could be adopted for assessment and treatment of sensorimotor deficits in bimanual functional tasks.


Assuntos
Lateralidade Funcional/fisiologia , Mãos/fisiologia , Propriocepção/fisiologia , Adulto , Fenômenos Biomecânicos , Feminino , Força da Mão , Voluntários Saudáveis , Humanos , Masculino , Adulto Jovem
19.
IEEE Int Conf Rehabil Robot ; 2019: 115-120, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374616

RESUMO

Rehabilitative exercise for people suffering from upper limb impairments has the potential to improve their neuro-plasticity due to repetitive training. Our study investigates the usefulness of Electroencephalogram and Electromyogram (EMG) signals for incorporation in humanrobot interaction loop. Twenty healthy participants recruited who performed a series of physical and cognitive tasks, with an inherent fatiguing component in those tasks. Here we report observed effects on EMG signals. Participants performed a Biceps curl repetitions using a suitable dumbbell in three phases. In phase 1, the initial weight was set to achieve maximum voluntary contraction (MVC). Phase 2 followed with 80 % MVC and phase 3 had 60% MVC. After each phase, they had a break around 3 minutes. EMG data were acquired from Biceps, Triceps, and Brachioradialis muscles. Different EMG features were explored to inform on muscle fatigue during this interaction. Comparing EMG during the first and last dumbbell of each phase demonstrated that the muscle fatigue had caused an increase in the average power (94% of cases) and amplitude (91%) and a decrease in the mean (80%) and the median frequency (57%) of EMG, which was more noticeable in Biceps. The results from integrated EMG showed a continuous rise in all three muscles which was more pronounced in Biceps muscle. Given these results, we identify EMG average power as the most reliable feature for informing on muscle fatigue.


Assuntos
Mãos/fisiologia , Fadiga Muscular , Músculo Esquelético/fisiologia , Robótica/instrumentação , Adulto , Eletroencefalografia , Eletromiografia , Terapia por Exercício , Feminino , Voluntários Saudáveis , Humanos , Masculino , Adulto Jovem
20.
IEEE Int Conf Rehabil Robot ; 2019: 169-174, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374625

RESUMO

Studies that investigate myoelectric prosthesis control commonly use non-disabled participants fitted with a simulated prosthetic device. This approach improves participant recruitment numbers but assumes that simulated movements represent those of actual prosthesis users. If this assumption is valid, then movement performance differences between simulated prosthesis users and normative populations should be similar to differences between actual prosthesis users and normative populations. As a first step in testing this assumption, the objective of this study was to quantify movement performance differences between simulated transradial myoelectric prosthesis hand function and normative hand function. Motion capture technology was used to obtain hand kinematics for 12 non-disabled simulated prosthesis participants who performed a functional object-manipulation task. Performance metrics, end effector movement, and grip aperture results were compared to 20 nondisabled participants who used their own hand during task execution. Simulated prosthesis users were expected to perform the functional task more slowly, with multiple peaks in end effector velocity profiles, and a plateau in grip aperture when reaching to pick up objects, when compared to non-disabled participants. This study confirmed these expectations and recommends that subsequent research be undertaken to quantify differences in actual myoelectric prosthesis hand function versus normative hand function.


Assuntos
Membros Artificiais , Simulação por Computador , Eletromiografia , Mãos/fisiologia , Desenho de Prótese , Fenômenos Biomecânicos , Feminino , Força da Mão , Humanos , Masculino , Análise e Desempenho de Tarefas , Adulto Jovem
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