Electromyogram

Emotion recognition is one of the important highlights of human emotional intelligence and has long been studied to be incorporated with machine intelligence argued to make machines even more intelligent. This paper aims to contribute to this field of study by enabling machines to recognize emotion from facial electromyogram (EMG) signals. This includes a compilation of the groups attempt to recognize basic facial expressions namely happy, angry, and sad through the use of EMG signals from facial muscles. The group extracted features from the three EMG signals from the face of two human subjects, a male and a female, and analyzed these features to serve as feature templates. Using a minimum-distance classifier, recognition rates exceeded the target accuracy - 85 percent - reaching 94.44 percent for both the male and female subjects.

Individuals with incomplete spinal cord injury (iSCI) retain some control of the partially paralyzed muscles, necessitating careful integration of functional electrical stimulation (FES) with intact motor function. In this communication, the volitional surface electromyogram (sEMG) from partially paralyzed muscle was used to detect the intent to step in an iSCI volunteer. The classifier was able to trigger the FES-assisted swing phase with a false positive rate less than 1% and true positive rate of 82% for left foot-off (FO) and 83% for right FO over 110 steps taken during three testing sessions spread over a week.

Motor improvements in chronic stroke recovery accrue from coupled protocols of bilateral movements and active neuromuscular stimulation. This experiment investigated coupled protocols and within-limb transfer between distal and proximal joint combinations. The leading question focused on within-limb transfer of coupled protocols on distal joints to a bimanual aiming task that involved proximal joints. Twenty-six volunteers completed one of three motor

As more and more intramuscular electromyogram (EMG) decomposition programs are being developed, there is a growing need for evaluating and comparing their performances. One way to achieve this goal is to generate synthetic EMG signals having known features. Features of interest are: the number of channels acquired (number of detection surfaces), the number of detected motor unit action potential (MUAP) trains, their timevarying firing rates, the degree of shape similarity among MUAPs belonging to the same motor unit (MU) or to different MUs, the degree of MUAP superposition, the MU activation intervals, the amount and type of additive noise.

 The purpose of this study was to provide objective information on the involvement of different abdominal and hip flexor muscles during various types of common training exercises used in rehabilitation and sport. Six healthy male subjects performed altogether 38 different static and dynamic training exercises – trunk and hip flexion sit-ups, with various combinations of leg position and support, and bi- and unilateral leg lifts. Myoelectric activity was recorded with surface electrodes from the rectus abdominis, obliquus externus, obliquus internus, rectus femoris, and sartorius muscles and with indwelling fine-wire electrodes from the iliacus muscle. The mean electromyogram amplitude, normalised to the highest observed value, was compared between static and dynamic exercises separately. The hip flexors were highly activated only in exercises involving hip flexion, either lifting the whole upper body or the legs. In contrast, the abdominal muscles showed marked activation both during trunk and hip flexion sit-ups. In hip flexion sit-ups, flexed and supported legs increased hip flexor activation, whereas such modifications did not generally alter the activation level of the abdominals. Bilateral, but not unilateral, leg lifts required activation of abdominal muscles. In trunk flexion sit-ups an increased activation of the abdominal muscles was observed with increased flexion angle, whereas the opposite was true for hip flexion sit-ups. Bilateral leg lifts resulted in higher activity levels than hip flexion sit-ups for the iliacus and sartorius muscles, while the opposite was true for rectus femoris muscles. These data could serve as a basis for improving the design and specificity of test and training exercises.

This paper reports experimental research undertaken to study the effect of variation of inter-electrode distance on the Electromyogram (EMG). The experiments were conducted on ten healthy subjects and they performed isometric contraction of their biceps of the right arm at 20, 50 and 80% of their maximal voluntary contraction (MVC). EMG was recorded using surface electrodes with the distance between the two active electrodes being 18 and 36mm. It has been observed that at low levels of muscle contraction there was no significant variation due to the change in the distance between the electrodes while at 50 and 80% of MVC there was a significant change in the amplitude of the EMG. Using Time-Frequency analysis of EMG, the study demonstrates a variation of the spectral content of the EMG with change in the IED. The study also has shown that there is a variation of the EMG with muscle contraction but that the comparison should be done if the distance between the electrodes has been kept constant.

A theoretical investigation of different electroneurogram recording techniques using electrode cuffs is presented. A new screened tripole arrangement is proposed with a higher inherent signal to interference ratio than the true tripole, which also allows the nulling of the residual electromyogram signal. The reduction in interference is small because the electrode impedance is large compared to the source resistance.

Muscular tension is assigned an important role in the development and maintenance of chronic pain syndromes. It is seen as a psychophysiological correlate of learned fear and avoidance behavior. Basic theoretical models emphasize classical conditioning of muscular responses as a mechanism of pain chronification. However, the empirical basis for this field is very small. Our aim was to investigate muscular factors in relation to unconditioned and conditioned pain stimuli. An experimental study was conducted using a differential classical conditioning paradigm with 18 patients with chronic back pain (BP) and tension-type headache (TTH), and 18 healthy controls (HC). A high-pitched sound served as the CS+, paired with an intracutaneous electric pain stimulus (US), while a neutral sound was used as the CSÀ. Simultaneously, integrated surface electromyograms (iEMGs) were recorded for seven muscle sites. Our hypothesis was that the pain patients would demonstrate enhanced conditionability. Baseline values between patients (TTH, BP) and HC showed no significant differences. Although the perception and pain thresholds were balanced, both patient groups revealed a higher number of significant muscular responses to the pain stimulus (UR) than the HC. All participants showed significant conditioned muscular responses, however, the patients displayed a higher number than the healthy controls. Furthermore a significant relation was found between muscular responses and the experience of pain 1 day after the experiment. Muscular responses can be learned via classical conditioning. TTH and BP patients revealed a higher number of unconditioned and conditioned responses.

This paper describes a novel hand gesture recognition system that utilizes both multi-channel surface electromyogram (EMG) sensors and 3D accelerometer (ACC) to realize user-friendly interaction between human and computers. Signal segments of meaningful gestures are determined from the continuous EMG signal inputs. Multi-stream Hidden Markov Models consisting of EMG and ACC streams are utilized as decision fusion method to recognize hand gestures. This paper also presents a virtual Rubik's Cube game that is controlled by the hand gestures and is used for evaluating the performance of our hand gesture recognition system. For a set of 18 kinds of gestures, each trained with 10 repetitions, the average recognition accuracy was about 91.7% in real application. The proposed method facilitates intelligent and natural control based on gesture interaction.

Objectives: To evaluate electromyogram (EMG) profiles in patients with three related conditions: fibromyalgia, chronic fatigue syndrome, and depression. Methods: We studied 44 healthy volunteers, 22 patients with fibromyalgia, 11 patients with chronic fatigue syndrome, and 10 patients admitted for depression. The trapezius electromyogram was recorded during maximally sustained, bilateral, 90 • abduction of the shoulders. EMG signal frequency and amplitude were measured throughout the test. Results: In the fibromyalgia group, isometric contraction duration was significantly shorter than in the other two patient groups (P < 0.001) and the EMG frequency and amplitude pattern indicated premature discontinuation of the muscle contraction. Findings in the chronic fatigue patients were similar to those in the healthy controls. The patients with depression had a distinctive EMG profile characterized by excessive initial motor-unit recruitment with a shift in the frequency spectrum. Conclusions: Fibromyalgia was associated with a specific EMG pattern indicating premature discontinuation of the muscle contraction. Therefore, maximal voluntary muscle contraction tests may be of limited value for assessing function in fibromyalgia patients. Chronic fatigue syndrome patients had similar EMG findings to those in the healthy controls. The EMG alterations in the patients with depression were consistent with manifestations of psychomotor retardation.

Little consensus exists in the literature regarding methods for determination of the onset of electromyographic (EMG) activity. The aim of this study was to compare the relative accuracy of a range of computer-based techniques with respect to EMG onset determined visually by an experienced examiner. Twenty-seven methods were compared which varied in terms of EMG processing (low pass filtering at 10, 50 and 500 Hz), threshold value (1, 2 and 3 SD beyond mean of baseline activity) and the number of samples for which the mean must exceed the defined threshold (20, 50 and 100 ms). Three hundred randomly selected trials of a postural task were evaluated using each technique. The visual determination of EMG onset was found to be highly repeatable between days. Linear regression equations were calculated for the values selected by each computer method which indicated that the onset values selected by the majority of the parameter combinations deviated significantly from the visually derived onset values. Several methods accurately selected the time of onset of EMG activity and are recommended for future use.

Childhood trauma may confer risk for adult psychopathology by altering emotional and physiological responses to subsequent stressors. Few studies have distinguished effects of childhood trauma from effects of current Axis I psychopathology on adult psychophysiological reactivity. The authors exposed 90 psychiatrically healthy police cadets to startling sounds under increasing threat of shock while assessing their eyeblink electromyogram (EMG), skin conductance (SC), and heart rate responses. When compared with those who did not endorse early trauma (n ϭ 65), cadets reporting childhood trauma (n ϭ 25) reported less positive emotion and showed greater SC responses across all threat levels. They also showed threat-dependent elevations in reported negative emotions and EMG responses. Results suggest that childhood trauma may lead to long-lasting alterations in emotional and psychophysiological reactivity even in the absence of current Axis I psychopathology.

Objective: To demonstrate the errors in surface electromyogram (EMG) interpretation that can be made when the EMG signal is not normalized. Design: A case study as a proof of principle. Main Outcome Measures: The EMG amplitude between the upper and lower portions of the rectus abdominis in one subject during a trunk curl when the EMG signal was normalized (expressed as a percentage of a maximum voluntary contraction) and the amplitude when the signal was expressed in raw, unnormalized arbitrary units or raw millivolts directly read from the instrumentation. Results: Interpretation of the unnormalized EMG signal suggests that a large difference in neural activation of the upper and lower sections of the rectus abdominis is occurring. In this condition the average activity in the lower rectus is 60.9% of that in the upper portion. This interpretation is incorrect. When the EMG signal is normalized, the differences between the upper and lower segments are reduced. When normalized, the lower segment activity is equal to that of the upper segment. Conclusions: Because of the inherent EMG signal variability, clinical interpretation of surface EMG signals requires normalization of the signal for physiologic interpretation and for comparison between bilateral muscles and between the same muscle on different days and between different subjects. (J Manipulative Physiol Ther 1999;22:444–6)

Stretching is usually part of warm-up routines in many sports, but it affects the subsequent muscle force; therefore, it could negatively influence post-activation potentiation (PAP), one of the warm-up's main effects. The aim of this study was to evaluate the acute effects of passive stretching on PAP and fibre conduction velocity (CV). Seven subjects underwent 2 experimental sessions, control (C) and stretching (S), each consisting of 2 series (7 min resting) of 3 maximal voluntary contractions (MVC) of biceps brachii (5 s isometric contraction, 10 s recovery). During the resting phase of the S session, the biceps brachii was passively stretched (5×45 s stretches, 15 s recovery). Root mean square (RMS), mean frequency (MF) and CV were calculated from electromyography. Peak torque (pT) and half-contraction time (½CT) were measured and normalised by the arm muscular area (pTn). After C, pTn increased and ½CT decreased (p<0.05); moreover, MF and CV increased (p<0.05). After S, ½CT increased (p<0.05) and RMS decreased (p<0.05). Passive stretching could blunt the effects of PAP, presumably due to mechanical and neuromuscular changes. The observed changes in CV suggest a possible decrease in Ca 2+ sensitivity in contractile proteins. Therefore, the use of passive stretching in warm-up routines remains questionable.

The present article reviews two recent books dealing with rather closely related subjects; in fact, they tend to complement and supplement reciprocally. Obviously, the electromyogram is a bioelectrical signal that often is mathematically manipulated in different ways to better extract its information. Moreover, its correlation with other bioelectric variables may become necessary.

The b-adrenergic blocker propranolol given within hours of a psychologically traumatic event reduces physiologic responses during subsequent mental imagery of the event. Here we tested the effect of propranolol given after the retrieval of memories of past traumatic events. Subjects with chronic post-traumatic stress disorder described their traumatic event during a script preparation session and then received a one-day dose of propranolol (n = 9) or placebo (n = 10), randomized and double-blind. A week later, they engaged in scriptdriven mental imagery of their traumatic event while heart rate, skin conductance, and left corrugator electromyogram were measured. Physiologic responses were significantly smaller in the subjects who had received post-reactivation propranolol a week earlier. Propranolol given after reactivation of the memory of a past traumatic event reduces physiologic responding during subsequent mental imagery of the event in a similar manner to propranolol given shortly after the occurrence of a traumatic event.

Muscle strength and, to a greater extent, power inexorably decline with ageing. Quantitative loss of muscle mass, referred to as ''sarcopenia'', is the most important factor underlying this phenomenon. However, qualitative changes of muscle fibres and tendons, such as selective atrophy of fast-twitch fibres and reduced tendon stiffness, and neural changes, such as lower activation of the agonist muscles and higher coactivation of the antagonist muscles, also account for the age-related decline in muscle function. The selective atrophy of fast-twitch fibres has been ascribed to the progressive loss of motoneurons in the spinal cord with initial denervation of fast-twitch fibres, which is often accompanied by reinnervation of these fibres by axonal sprouting from adjacent slow-twitch motor units (MUs). In addition, single fibres of older muscles containing myosin heavy chains of both type I and II show lower tension and shortening velocity with respect to the fibres of young muscles. Changes in central activation capacity are still controversial. At the peripheral level, the rate of decline in parameters of the surface-electromyogram power spectrum and in the action-potential conduction velocity has been shown to be lower in older muscle. Therefore, the older muscle seems to be more resistant to isometric fatigue (fatigueparadox), which can be ascribed to the selective atrophy of fast-twitch fibres, slowing in the contractile properties and lower MU firing rates. Finally, specific training programmes can dramatically improve the muscle strength, power and functional abilities of older individuals, which will be examined in the second part of this review.

The present article reviews two recent books dealing with rather closely related subjects; in fact, they tend to complement and supplement reciprocally. Obviously, the electromyogram is a bioelectrical signal that often is mathematically manipulated in different ways to better extract its information. Moreover, its correlation with other bioelectric variables may become necessary.

Two studies are presented, in which emotional vocal recordings were made using a computer emotion induction task and an imagination technique. Concurrent recordings were made of a variety of physiological parameters, including electroglottograph, respiration, electrocardiogram, and surface electromyogram (muscle tension). Acoustic parameters pertaining to voice quality, including F0 floor, F0 range, jitter and spectral energy distribution were analysed and compared

Purpose: To date, only one case of asterixis associated with the use of gabapentin (GBT) has been reported. No data, instead, are available on the occurrence of asterixis related to a dementing encephalopathy during GBT therapy in the elderly. Methods: Case reports of two elderly patients, one with asterixis, the other with asterixis and encephalopathy, associated with the use of GBT, as adjunctive therapy, at dosages of 900 to 3600 mg/day are given. In one patient, GBT was added to oxcarbazepine (OXCBZ). Findings: Both patients experienced resolution of the clinically apparent asterixis, and of the toxic encephalopathy, on discontinuation or reduction of GBT dosages. One patient developed asterixis after drug rechallenge. In the patient on OXCBZ, the analysis of the electromyogram (EMG) activity showed the occurrence of a subclinical asterixis. Conclusions: Our study indicates that high doses of GBT may induce asterixis related to a reversible encephalopathy. Low doses of GBT, instead, may induce a disabling asterixis when given in combination with OXCBZ because of a synergistic interaction between these drugs. D

Periaqueductal gray (PAG) and nucleus tractus solitarius (NTS) are important centres for regulation of cardiorespiratory function in cats. We aimed to study the effects of specific PAG stimulation on cardiorespiratory parameters in the rat. Microinjection of D,L-homocysteic acid (DLH) into dorsolateral PAG of anaesthetised rats, led to: marked increases in respiratory frequency (RF) and amplitude of diaphragmatic electromyogram, decreases in inspiratory and expiratory durations, and increased blood pressure and heart rate. Following injection of propranolol (150 pmol, 30 nl), a beta-adrenergic antagonist, into the commissural subnucleus of NTS, the DLH-induced increase in RF was markedly attenuated. Inspiratory neurones (late I cells) in NTS were excited upon stimulation of PAG and their increased activity was accompanied by increased RF. The changes in activity of the late I cells in response to stimulation of dorsolateral PAG provide physiological evidence of a link, possibly noradrenergic, between the two nuclei and involvement of the NTS in control of respiratory functions orchestrated by the PAG.

The bioelectrical potentials generated within the human body are the result of electrochemical activity in the excitable cells of the nervous, muscular or glandular tissues. The ionic potentials are measured using biopotential electrodes which convert ionic potentials to electronic potentials. The commonly monitored biopotential signals are Electrocardiogram (ECG), Electroencephalogram (EEG) and Electromyogram (EMG). The electrodes used to monitor biopotential signals are Ag-AgCl and gold, which require skin preparation by means of scrubbing to remove the dead cells and application of electrolytic gel to reduce the skin contact resistance. The gels used in biopotential recordings dry out when used for longer durations and add noise to the signals and also prolonged use of gels cause irritations and rashes to skin. Also noises such as motion artifact and baseline wander are added to the biopotential signals as the electrode floats over the electrolytic gel during monitoring. To overcome these drawbacks, dry electrodes are used, where the electrodes are held against the skin surface to establish contact with the skin without the need for electrolytic fluids or gels. The major drawback associated with the dry electrodes is the high skin-electrode impedance in the low frequency range between 0.1-120 Hz, which makes it difficult to acquire clean and noise free biopotential signals. The paper presents the design and development of biopotential data acquisition and processing system to acquire biopotential signals from dry electrodes. The electrode-skin-electrode-impedance (ESEI) measurements was carried out for the dry electrodes by impedance spectroscopy. The biopotential signals are processed using an instrumentation amplifier with high CMRR and high input impedance achieved by boot strapping the input terminals. The signals are band limited by means of a second order Butterworth band pass filters to eliminate noise. The processed biopotential signals are digitized and transmitted wirelessly to a remote monitoring station.

The present article reviews two recent books dealing with rather closely related subjects; in fact, they tend to complement and supplement reciprocally. Obviously, the electromyogram is a bioelectrical signal that often is mathematically manipulated in different ways to better extract its information. Moreover, its correlation with other bioelectric variables may become necessary.

Several areas in the brainstem and forebrain are important for the modulation and expression of the sleep/wake cycle. Even if the first observations of biochemical events in relation to sleep were made only 40 years ago, it is now well established that several neurotransmitters, neuropeptides, and neurohormones are involved in the modulation of the sleep/wake cycle.Serotonin has been known for many years to play a role in the modulation of sleep, however, it is still very controversial how and where serotonin may operate this modulation. Early studies suggested that serotonin is necessary to obtain and maintain behavioral sleep (permissive role on sleep).However, more recent microdialysis experiments provide evidence that the level of serotonin during W is higher in most cortical and subcortical areas receiving serotonergic projections. In this view the level of extracellular serotonin would be consistent with the pattern of discharge of the DRN serotonergic neurons which show the highest firing rate during W, followed by a decrease in slow wave sleep and by virtual electrical silence during REM sleep.This suggests that during waking serotonin may complement the action of noradrenaline and acetylcholine in promoting cortical responsiveness and participate to the inhibition of REM-sleep effector neurons in the brainstem (inhibitory role on REM sleep).The apparent inconsistency between an inhibitory and a facilitatory role played by serotonin on sleep has at least two possible explanations. On the one hand serotonergic modulation on the sleep/wake cycle takes place through a multitude of post-synaptic receptors which mediate different or even opposite responses; on the other hand the achievement of a behavioral state depends on the complex interaction between the serotonergic and other neurotransmitter systems.The main aim of this commentary is to review the role of brain serotonin in relation to the sleep/wake cycle. In particular we highlight the importance of microdialysis for on-line monitoring of the level of serotonin in different areas of the brain across the sleep/wake cycle.

Few studies have been carried out on the changes in biomechanical loading on low-back tissues during prolonged lifting. The purpose of this paper was to develop a model for continuously estimating erector spinae muscle loads during repetitive lifting and lowering tasks. The model was based on spine kinematics and bilateral lumbar and thoracic erector spinae electromyogram (EMG) signals and was developed with the data from eight male subjects. Each subject performed a series of isometric contractions to develop extensor moments about the low back. Maximum voluntary contractions (MVCs) were used to normalize all recorded EMG and moment time-histories. Ramp contractions were used to determine the non-linear relationship between extensor moments and EMG amplitudes. In addition, the most appropriate low-pass filter cut-off frequencies were calculated for matching the rectified EMG signals with the moment patterns. The mean low-pass cut-off frequency was 2.7 (0.4) Hz. The accuracy of the non-linear EMG-based estimates of isometric extensor moment were tested with data from a series of six rapid contractions by each subject. The mean error over the duration of these contractions was 9.2 (2.6)% MVC. During prolonged lifting sessions of 20 min and of 2 h, a model was used to calculate changes in muscle length based on monitored spine kinematics. EMG signals were first processed according to the parameters determined from the isometric contractions and then further processed to account for the effects of instantaneous muscle length and velocity. Simple EMG estimates were found to underestimate peak loading by 9.1 (4.0) and 25.7 (11.6)% MVC for J.R. Potvin (12N) eccentric and concentric phases of lifting respectively, when compared to load estimates based on the mechanically corrected EMG. To date, the model has been used to analyze over 5300 lifts.

AbstractÐStudies on the re¯ex modulation of vertebrate locomotion have been conducted in many dierent laboratories and with many dierent preparations: for example, lamprey swimming, bird¯ight, quadrupedal walking in cats and bipedal walking in humans. Emerging concepts are that re¯exes are task-, phase-and context-dependent. To function usefully in a behaviour such as locomotion wherein initial conditions change from step to step, re¯exes would have to show modulation.

This project proposes to use the analysis of physiological signals, such as the electroencephalogram (EEG), electromyogram (EMG) electrocardiogram (ECG) and electro-oculogram (EOG), to control sound synthesis algorithms in order to build a biologically driven musical instrument. This project took place during the eNTERFACE'05 summer workshop in Mons, Belgium. Over four weeks specialists from the fields of brain-computer interfaces and sound synthesis worked together to produce biologically controlled musical instruments playable in real-time.

Electromyogram (EMG) analyses (surface, intramuscular and evoked potentials) in studies of muscle function have attracted increasing attention during recent years and have been applied to assess muscle endurance capacity, anaerobic and lactate thresholds, muscle biomechanics, motor learning, neuromuscular relaxation, optimal walking and pedalling speeds, muscle soreness, neuromuscular diseases, motor unit (MU) activities (MU recruitment and rate coding), and skeletal muscle fatigue. This paper deals with the use of EMG analyses employed in the area of applied physiology and is divided into three sections: surface EMG analyses; intramuscular EMG analyses; and evoked potential analyses.

We used positron emission tomography to study neural mechanisms underlying intensely pleasant emotional responses to music. Cerebral blood flow changes were measured in response to subject-selected music that elicited the highly pleasurable experience of ''shivers-down-the-spine'' or ''chills.'' Subjective reports of chills were accompanied by changes in heart rate, electromyogram, and respiration. As intensity of these chills increased, cerebral blood flow increases and decreases were observed in brain regions thought to be involved in reward͞motivation, emotion, and arousal, including ventral striatum, midbrain, amygdala, orbitofrontal cortex, and ventral medial prefrontal cortex. These brain structures are known to be active in response to other euphoriainducing stimuli, such as food, sex, and drugs of abuse. This finding links music with biologically relevant, survival-related stimuli via their common recruitment of brain circuitry involved in pleasure and reward.

Electromyogram signals (EMGs) contain valuable information that can be used in man-machine interfacing between human users and myoelectric prosthetic devices. However, EMG signals are complicated and prove difficult to analyze due to physiological noise and other issues. Computational intelligence and machine learning techniques, such as artificial neural networks (ANNs), serve as powerful tools for analyzing EMG signals and creating optimal myoelectric control schemes for prostheses. This research examines the performance of four different neural network architectures (feedforward, recurrent, counter propagation, and self organizing map) that were tasked with classifying walking speed when given EMG inputs from 14 different leg muscles. Experiments conducted on the data set suggest that self organizing map neural networks are capable of classifying walking speed with greater than 99% accuracy.

Frequency-related parameters derived from the uterine electromyogram (EMG) signals are widely used in many pregnancy monitoring and preterm delivery prediction studies. Although they are classical parameters, they are well suited for quantifying uterine EMG signals and have many advantages over amplitude-related parameters. The present work aims to compare various frequency-related parameters according to their classification performances (pregnancy vs. labor) using the receiver operating characteristic (ROC) curve analysis. The comparison between the parameters indicates that median frequency is the best frequency-related parameter that can be used for distinguishing between pregnancy and labor contractions. We conclude that median frequency can be the representative frequency-related parameter for classification problems of uterine EMG.

In many studies and applications that include direct human involvement-such as human-robot interaction, control of prosthetic arms, and human factor studies-hand force is needed for monitoring or control purposes. The use of inexpensive and easily portable active electromyogram (EMG) electrodes and position sensors would be advantageous in these applications compared to the use of force sensors, which are often very expensive and require bulky frames. Multilayer perceptron artificial neural networks (MLPANN) have been used commonly in the literature to model the relationship between surface EMG signals and muscle or limb forces for different anatomies. This paper investigates the use of fast orthogonal search (FOS), a time-domain method for rapid nonlinear system identification, for elbow-induced wrist force estimation. It further compares the forces estimated using FOS with the forces estimated by MLPANN for the same human anatomy under an ensemble of operational conditions. In this paper, the EMG signal readings from upper arm muscles involved in elbow joint movement and sensed elbow angular position and velocity are utilized as inputs. A single degree-of-freedom robotic experimental testbed has been constructed and used for data collection, training and validation.

In order to assist physically disabled, injured, and/or elderly persons, we have been developing exoskeleton robots for assisting upper-limb motion, since upper-limb motion is involved in a lot of activities of everyday life. This paper proposes a mechanism and control method of a mobile exoskeleton robot for 3DOF upper-limb motion assist (shoulder vertical and horizontal flexion/extension, and elbow flexion/extension motion assist). The exoskeleton robot is mainly controlled by the skin surface electromyogram (EMG) signals, since EMG signals of muscles directly reflect how the user intends to move. The force vector at the end-effector is taken into account to generate the natural and smooth hand trajectory of the user in the proposed control method. An obstacle avoidance algorithm is applied to prevent accidental collision between the user's upper-limb and the robot frame. The experiment was performed to evaluate the effectiveness of the proposed exoskeleton robot.

The aim of this study was to evaluate muscle fatigue in upper body muscles during 100-m all-out front crawl. Surface electromyogram (EMG) was collected from the pectoralis major, latissimus dorsi and triceps brachii muscles of 11 experienced swimmers. Blood lactate concentration level increased to 14.1 ± 2.9 mmol l -1 5 min after the swim. The velocity, stroke length and stroke rate calculated based on video analysis decreased by 15.0, 5.8 and 7.4%, respectively, during the swim. EMG amplitude of the triceps and the lower part of the latissimus muscles increased, whilst the mean power frequency (MNF) of all muscles significantly decreased by 20-25%. No significant differences in the relative MNF decrease were observed amongst the muscles; however, the differences in the rate of the MNF decrease between the lower part of the latissimus and the triceps brachii muscles were found (P \ 0.05). The time of rest between the muscle activation of the two consecutive arm strokes at the end of swimming was extended (P \ 0.05). It was concluded that 100-m all-out crawl induced significant fatigue with no evident differences amongst the analysed muscles.

This paper discusses a brain-computer interface through electrooculogram (EOG) and electromyogram (EMG) signals. In situations of disease or trauma, there may be inability to communicate with others through means such as speech or typing. Eye movement tends to be one of the last remaining active muscle capabilities for people with neurodegenerative disorders, such as amyotrophic lateral sclerosis (ALS) also known as Lou Gehrig's disease. Thus, there is a need for eye movement based systems to enable communication. To meet this need, we proposed a system to accept eye-gaze controlled navigation of a particular letter and EMG based click to enter the letter. Eye -gaze direction (angle) is obtained from EOG signals and EMG signal is recorded from eyebrow muscle activity. A virtual screen keyboard may be used to examine the usability of the proposed system.