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Motor imagery-based brain computer interface (BCI) technology has motor rehabilitation as one of its main fields of application. The use of a BCI as a neuroprosthetic for paralyzed limb motor restoration implies normally absence of muscle activity. It is still an open question whether residual motor activity in healthy individuals or in patients causes a bias in the modulation of a motor imagery-based...
Classification of surface electromyogram (sEMG) signal is important for various applications such as prosthetic control and human computer interface. Surface EMG provides a better insight into the strength of muscle contraction which can be used as control signal for different applications. Due to the various interference between different muscle activities, it is difficult to identify movements using...
This paper presents our experience with developing a portable wireless medical sensor device. We use National Instruments (NI) devices and LabView for measurements studying fatigue of patients suffering multiple sclerosis (MS). Fatigue is a very frequent symptom perceived by MS patients, but the disease mechanism is poorly understood. Many efforts have been made to increase the understanding of this...
Tremor constitutes the most common movement disorder; in fact 14.5% of population between 50 to 89 years old suffers from it. Moreover, 65% of patients with upper limb tremor report disability when performing their activities of daily living (ADL). Unfortunately, 25% of patients do not respond to drugs or neurosurgery. In this regard, TREMOR project proposes functional compensation of upper limb tremors...
This article describes a patient training evolution to achieve myoelectric control in the remnant limb. The methodology is divided in two main stages: (i) the training procedure, where the patient is submitted to a protocol for educating the muscles of the remnant limb, and (ii) myoelectric signal acquisition and analysis, in order to measure the patient evolution to reach different contraction levels...
Analysis of muscle activity by electrophysiological techniques is commonly used to analyze biomechanics. Although the simultaneous and intuitive understanding of both muscle activity and body motion is important in various fields, it is difficult to realize. This paper proposes a novel technique for visualizing physiological signals related to muscle activity by means of surface electromyography....
In this paper, we examine the potential of electromyographic (EMG) and acceleration measurements in discriminating patients with Parkinson's disease (PD) from healthy persons. Two types of muscle contractions are examined: static contractions of biceps brachii muscles and elbow extension movements. Twelve features are extracted from static and ten features from extension measurements. These features...
Recently, there has been an increasing interest in upper-limb prosthetic hand control, but most of these studies focus on the detection of exact motion intentions. Therefore, the responses to unexpected disturbance are not taken into consideration. On the other hand, unimpaired people respond to external disturbances by reflexive responses, hence, it is important to explore how this kind of reactive...
The present study investigates the behavior of action potential conduction velocity (CV) on each repetition of an isokinetic test set and on each set as a whole. A total of seven healthy men (27.7 ± 2.8 yrs, 1.74 ± 0.06 m, and 79.6 ± 11.0 Kg) performed 3 (three) sets of 10 (ten) maximal concentric repetitions of dominant knee extension at 60°/s on an isokinetic dynamometer, with 1 minute of rest interval...
We recently developed a novel active implant for the treatment of severe stress urinary incontinence. This innovative medical device has been developed with the main purpose of reducing the mean urethral occlusive pressure of the current prosthesis. This goal is achieved by detecting circumstances implying either high or low intra-abdominal pressures by a single 3-axis accelerometer. In fact, posture...
This paper proposes a real-time processing algorithm which estimates a subject knee moments using some joint angle data and EMGs of involved muscles. This algorithm will be essential part for the control system design of exoskeletal robotic devices. In order for this algorithm to accurately predict joint moments, it is necessary to know the one's musculo-skeletal properties, which is virtually impossible...
A differential, time-invariant, surface electromyogram (sEMG) model has been implemented. While it is based on existing EMG models, the novelty of this implementation is that it assigns more accurate distributions of variables to create realistic motor unit (MU) characteristics. Variables such as muscle fibre conduction velocity, jitter (the change in the interpulse interval between subsequent action...
Restoring walking functions will greatly improve the foot-drop patients' life quality. In this work, we sampled 10 healthy subjects' gait data when walking in 4 different stride frequency overground and developed a dynamic Functional Electrical Stimulation (dFES) system for foot-drop patients' walk training, using the processed tibialis anterior (TA) muscle EMG signal. The data sampled under the new...
Despite growing interest in the behavior of electromyographic signals during muscle fatigue, few studies investigate fatigue recovery. In this work, we use surface electromyographic signals to determine the recovery time after isometric fatigue of the biceps brachii muscle in 90° flexion of the non-dominant elbow. Sixty volunteers were arranged into six experimental groups. Experiments were performed...
Motor unit layout algorithms have a significant effect on motor unit fibre densities recorded. Motor unit fibre densities are affected by both the method used to place the motor unit territories, and the mechanism by which muscle fibres are assigned to motor units. The first of these should emulate the process by which separate motor neurons create overlapping territories that cover the muscle cross...
This study is aimed to investigate the muscle activity changes, including fatigue effects and the symmetry of muscle activation between affected and unaffected sides during a 10-day body weight support treadmill training program using a focal ischemia rat hindlimb model. Our findings of the MPF drop after stroke might indicate fatigue effects due to the compensation loading share of the ipsilateral...
We have reported earlier a new method for estimating reflex threshold in spastic muscles of stroke survivors, using controlled amplitude taps superimposed on progressive and controlled muscle indentation of the bicipital tendon in the bicipital fossa. This muscle indentation is done with a linear actuator positioned over the biceps muscle tendon at the elbow. In the course of testing for increased...
Most previous studies of electromyography (EMG) pattern recognition control of multifunctional myoelectric prostheses adopted a conventional sampling rate that is commonly used in EMG research fields. However, it is unknown whether using a lower sampling rate in EMG acquisition still preserves sufficient neural control information for accurate classification of user movement intents. This study investigated...
A motion controller which has an acceleration sensor increases reality and intuitiveness in sports games. But we adjust not only visible posture but also invisible force like stiffness and viscosity when we play sports. We propose a game controller using player's movement and force by using acceleration and electromyogram(EMG). In this research, we compared conventional motion controller and proposed...
Frequency domain analyses of changes in electromyographic (EMG) signals over time are frequently used to assess muscle fatigue. Fourier based approaches are typically used in these analyses, yet Fourier analysis assumes signal stationarity, which is unlikely during dynamic contractions. Wavelet based methods of signal analysis do not assume stationarity and may be more appropriate for joint time-frequency...
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