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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...
Mechanomyography (MMG) is a technique for measuring muscle oscillations and fatigue. Functional electrical stimulation (FES) has been applied to control movements mainly in people with spinal cord injury (SCI). The goal of this study is the application of the MMG signal as a tool to investigate muscle response during FES. Ten healthy individuals (HI) and three SCI were submitted to four FES profiles...
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...
F-wave persistence is a frequently reported parameter for nerve conduction studies. F-wave activities are generated through backfiring of motor neurons. F-wave persistence is designed to estimate the backfiring rate. Through computational models and probability analyses, we demonstrated that the F-wave persistence definition is deficient in providing a robust and consistent estimate of the backfiring...
The objective of this work is to study and design a portable non invasive prototype which allows us to supervise the mastication frequency and pressure for specific meals, performing an analysis of sounds and pressures generated by facial muscles when they are chewing. These variables have a direct influence on people nutritious and dietary habits; also, a quickly eating makes people ingest a lot...
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...
Mechanomyography (MMG) registers lateral oscillations of contracting muscles. Functional electrical stimulation (FES) improves the rehabilitation of paraplegic subjects and can be used in neuroprosthesis control. During FES application, muscular contraction responses may vary, possibly due to fatigue or adaptation of nerve cells face to electrical stimuli. This study measured the differences in MMG...
Mechanical impedance is a complex number and a system's property. Impedance of human arm is the control variable when the central nervous system coordinates a motion. This research proposes a new method for measuring the mechanical impedance as a complex number. Impedance is measured at the hand point while sinusoidal perturbation is applied. That helps extracting the real and imaginary part of the...
Within the framework of multibody dynamics, a 3D large scale neuromusculoskeletal model of the human body is presented. To characterize the dynamics of skeletal muscle, a phenomenological model of energy expenditure was developed for estimating energy consumption during normal locomotion. Such model is able for predicting thermal and mechanical energy liberation under submaximal activation, muscle...
Cardiac volume estimation in the Left Ventricle from impedance or admittance measurement is subject to two major sources of error: parallel current pathways in surrounding tissues and a non uniform current density field. The accuracy of volume estimation can be enhanced by incorporating the complex electrical properties of myocardium to identify the muscle component in the measurement and by including...
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...
Atherosclerotic plaque complication is a major cause of vascular accidents. Although a variety of factors have been proposed as key factors in these process, the mechanism that contribute to this problem remain to be characterized. Previously we demonstrated that changes in arterial wall viscous and elastic properties and/or in the filtering function (FF) could be part of the arterial wall alterations...
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....
We quantified the mechanical abnormalities of the spastic wrist in chronic stroke survivors, and determined whether these findings were representative of those recorded at the elbow and ankle joints. System identification techniques were used to characterize the mechanical abnormalities of these joints and to identify the contribution of intrinsic and reflex stiffness to these abnormalities. Modulation...
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...
We have developed a vector Doppler ultrasound imaging method to directly quantify the magnitude and direction of muscle and tendon velocities during movement. The goal of this study was to evaluate the feasibility of using vector Tissue Doppler Imaging (vTDI) for estimating the tibialis anterior tendon velocities during dorsiflexion in children with cerebral palsy who have foot drop. Our preliminary...
Since the introduction of the Conducted Electrical Weapons (CEW) several studies have been conducted and multiple reports have been published on safety of these devices from a medical point of view. Use of these devices in different situations and reported deaths attracts media attention and causes general anxiety around these devices. These devices have several limitations- such as rate of fire or...
This paper presents a nonlinear dynamic model for the purpose of modeling vowels uttered by patients who have problem in the control of voice box muscles. The proposed model will be utilized in the detection of speech pathologies and also automatic speech recognition systems to enhance patients' communication capabilities. The model of this study utilizes feedback, and also a sigmoid nonlinear function...
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