56 research outputs found
Effects of the physiological parameters on the signal-to-noise ratio of single myoelectric channel
<p>Abstract</p> <p>Background</p> <p>An important measure of the performance of a myoelectric (ME) control system for powered artificial limbs is the signal-to-noise ratio (SNR) at the output of ME channel. However, few studies illustrated the neuron-muscular interactive effects on the SNR at ME control channel output. In order to obtain a comprehensive understanding on the relationship between the physiology of individual motor unit and the ME control performance, this study investigates the effects of physiological factors on the SNR of single ME channel by an analytical and simulation approach, where the SNR is defined as the ratio of the mean squared value estimation at the channel output and the variance of the estimation.</p> <p>Methods</p> <p>Mathematical models are formulated based on three fundamental elements: a motoneuron firing mechanism, motor unit action potential (MUAP) module, and signal processor. Myoelectric signals of a motor unit are synthesized with different physiological parameters, and the corresponding SNR of single ME channel is numerically calculated. Effects of physiological multi factors on the SNR are investigated, including properties of the motoneuron, MUAP waveform, recruitment order, and firing pattern, etc.</p> <p>Results</p> <p>The results of the mathematical model, supported by simulation, indicate that the SNR of a single ME channel is associated with the voluntary contraction level. We showed that a model-based approach can provide insight into the key factors and bioprocess in ME control. The results of this modelling work can be potentially used in the improvement of ME control performance and for the training of amputees with powered prostheses.</p> <p>Conclusion</p> <p>The SNR of single ME channel is a force, neuronal and muscular property dependent parameter. The theoretical model provides possible guidance to enhance the SNR of ME channel by controlling physiological variables or conscious contraction level.</p
A microcomputer controlled experimental set-up for neurophysiological diagnosis of arm movement disorders
A microcomputer controlled mechanical equipment has been realized at the V Clinica Neurologica of the Hospital Umberto of Rome with the aim of perturbing the planar movement of the human ar
Apparecchiatura per la perturbazione meccanica e magnetica del movimento planare degli arti superiori
It is presented a computerized apparatus able to give either a mechanical or a magnetical perturbation to the arm of the patient in ordwer to elicit the stretch reflex
Applicazione di tecniche di simulazione alla progettazione di mioprocessori
In questa prima fase di applicazione di tecniche non invasive di registrazione del segnale elettromiografico di superficie si è osservato che una stima della forza può essere ottenuta da rettificazione a onda intera, seguita da filtraggio passa basso
A user fiendly program for ECG acquisition and processing in Windows 3.1 environment
In order to verify the rejection effects in transplanted patients, a software program has been developed for the analysis of the ECG
A multifiltering demodulator for adaptive estimation of muscular efforts from surface EMG
In order to estimate the muscular effort from surface electromyogram a demodulator with three level of filters has been adopted
Evoked potentials with personal computer
One of the most frequently used examination in neurological diagnosis is constituted by the evoked potential (EP). In this comunication we present our project of a computerized apparatus for the acquisition and processing of EP. Firstly devoped for the analysis and processing of EP in response to visual stimuli (VEP, Visual Evoked Potentials), now is also ready for Somatosensory (SEP) and acoustical (AEP) stimuli
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