The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
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...
The paper presents an ongoing investigation into the feasibility of distinguishing between healthy young and older adults, but more specifically into the nature of the features that would provide this distinction. The present study compared the performance of forward, backward, and branch and bound feature selection algorithms when applied to electroencephalography and electromyography data. The results...
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...
Dynamic joint stiffness defines the dynamic relationship between the position of the joint and the torque acting about it. Joint stiffness consists of two components: intrinsic and reflex stiffness. Previous work from our lab has shown that subjects can alter their reflex stiffness voluntarily and independently of intrinsic stiffness. Numerous studies have investigated whether reflex stiffness is...
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...
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...
Practical Brain-Computer Interfaces (BCIs) for disabled people should allow them to use all their remaining functionalities as control possibilities. Sometimes these people have residual activity of their muscles, most likely in the morning when they are not exhausted. In this work we fuse electromyographic (EMG) with electroencephalographic (EEG) activity in the framework of a so called “Hybrid-BCI”...
This paper presented an estimation method of multi-directional and proportional fluid wrist motion intents via sEMG using a non-negative muscle synergy matrix and a joint synergy matrix. A real-time experiment was performed to validate feasibility of the proposed method, and the experimental environment was realized for the individuals with wrist amputation. Only four wrist movements were predefined...
Recent studies on identifying multiple activation states from mechanomyogram (MMG) signals for the purpose of controlling switching interfaces have employed pattern recognition methods where MMG signal features from multiple muscle sites are extracted and classified. The purpose of this study is to determine if MMG signal features retain enough discriminatory information to allow reliable continuous...
A novel integrative model for simulating the surface EMG signal during pathological tremor is presented. The model combines neuromuscular elements, biomechanical descriptions, and surface EMG generation. First single motor unit spike trains are generated based on the sum of the simulated descending drive, afferent input and an oscillatory noise causing tremor. Based on this activity pattern, the muscle...
To evaluate the proficiency level of an operating myoelectric hand, we proposed an evaluation index consisting of the accuracy and the reproducibility of electromyography (EMG) signal patterns. Our proposed method is not an absolute evaluation because we use bio-signals, so it is necessary to verify the correlation between the proposed index and performance evaluation to confirm the usefulness of...
This paper describes a means of controlling the knee movement of a powered knee prosthesis during non-weight-bearing activity such as sitting, by utilizing surface EMG from the quadriceps and hamstring muscle groups in the residual limb. The method was implemented on a powered prosthesis on three amputee subjects, and experimental results are presented characterizing the ability of the amputee subjects...
The parameters commonly employed for muscular fatigue (MF) analysis, the mean frequency (Fmean) and median frequency (Fmedian) of surface EMG (SEMG) spectra, did not present consistent results for exercises performed at low to moderate intensities. For overcoming this limitation, the present study proposes the use of principal component (PC) analysis of SEMG spectra for MF monitoring. The SEMG from...
A musculoskeletal model of wrist flexors comprising musculoskeletal dynamics and limb anatomy was experimentally validated with healthy subjects during maximum voluntary contractions. Electromyography signals recorded from flexors were used as input, while measured torques exerted by the hand were compared to the torques predicted by the model. The root mean square error and the normalized root mean...
Understanding the relationship between neural activity in motor cortex and muscle activity during movements is important both for basic science and for the design of neural prostheses. While there has been significant work in decoding muscle EMG from neural data, decoders often require many parameters which make the analysis susceptible to overfitting, which reduces generalizability and makes the...
Functional connectivity in the resting state based on BOLD functional MRI (fMRI) has been used mainly to observe brain networks while subjects `do nothing'. The same principle, however, can be used for any other steady-state brain condition. In this study, we compared the connectivity of the motor area during simple finger tapping with and without real time neuro-feedback of the activation in the...
We present a device for recording and analyzing upper limb movements and muscle activities in a single unit. The device's outputs are related to aspects of clinical assessment such as joint coordination, fatigue and muscle synergies. A comparison with an optoelectronic motion capture system was also carried out during a hand to mouth and a hand to contralateral shoulder task. High correlation was...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.