Evaluation of Muscle Fatigue in Spinal Surgery Instruments Based on sEMG-JASA / 中国医疗器械杂志

Based on the joint analysis of EMG spectrum and amplitude method (JASA), a study on muscle fatigue assessment of spinal surgical instruments based on surface EMG signals was carried out, and a comparative evaluation of the operating comfort before and after the optimization of spinal surgical instruments was completed. A total of 17 subjects were recruited to collect the surface EMG signals of their brachioradialis and biceps. Five surgical instruments before and after optimization were selected for data comparison, and the operating fatigue time proportion of each group of instruments under the same task was calculated based on the RMS and MF eigenvalues. The results showed that when completing the same operation task, the operation fatigue time of the surgical instruments before optimization was significantly higher than that after optimization (P<0.05); there was no significant difference in the fatigue status of brachioradialis and biceps when operating the same instrument (P>0.05). These results provide objective data and reference for the ergonomic design of surgical instruments and fatigue damage protection.

Design and Experimental Research of Synchronous Acquisition System of EMG and Blood Oxygen Signal / 中国医疗器械杂志

In this study, a surface electromyography (sEMG) and blood oxygen signal real-time monitoring system is designed to explore the changes of physiological signals during muscle fatigue, so as to detect muscle fatigue. The analysis method of sEMG and the principle of blood oxygen detection are respectively introduced, and the system scheme is expounded. The hardware part of the system takes STM32 as the core. Conditioning module composition; blood oxygen signal acquisition is based on near infrared spectroscopy (NIRS), specifically including light source, light source driving, photoelectric conversion, signal conditioning and other modules. The system software part is based on the real-time uC/OS-III software system. The characteristic parameters of sEMG were extracted by isometric contraction local muscle fatigue experiment; the relative changes of oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) were calculated in the forearm blocking experiment, thereby verifying that the system collects two signals effectiveness.

A pilot study on the functional outcome using markerless motion analysis tool and surface emg of nerve transfers for upper trunk brachial plexus injuries

INTRODUCTION@#Brachial plexus injuries (BPI) have devastating functional effects. Clinical outcomes of BPI reconstruction have been documented in literature; however, these do not use EMG and quantitative kinematic studies.@*OBJECTIVE@#This study aims to use a markerless motion analysis tool (KINECT) and surface EMG to assess the functional outcomes of adult patients with traumatic upper trunk BPI who have undergone nerve transfers for the shoulder and elbow in comparison to the normal contralateral limb.@*METHODS@#This is an exploratory study which evaluated three participants with BPI after nerve reconstruction. KINECT was used to evaluate the kinematics (range of motion, velocity, and acceleration) and the surface EMG for muscle electrical signals (root mean square, peak EMG signal, and peak activation time) of the extremities. The means of each parameter were computed and compared using t-test or Mann-Whitney U test.@*RESULTS@#Participant C, with the best clinical recovery, showed mostly higher KINECT and EMG values for the BPI extremity. There was a significant difference between the KINECT data of Participants A and B, with lower mean values for the BPI extremity. Most of the EMG results showed lower signals for the BPI extremity, with statistical significance.@*CONCLUSION@#The KINECT and surface EMG provide simple, cost-effective, quick, and objective assessment tools. These can be used for monitoring and as basis for formulating individualized interventions. A specific algorithm should be developed for the KINECT sensors to address errors in data collection. A fine needle EMG may be more useful in evaluating the muscles involved in shoulder external rotation.

Design of Paravertebral Muscle Monitoring System Based on Surface Electromyography / 中国医疗器械杂志

In order to diagnose and evaluate the human spinal lesions through the paravertebral muscles, a paravertebral muscle monitoring system based on surface EMG signals was designed. The system used surface mount electrodes to obtain the surface myoelectric signal (sEMG) of paravertebral muscle. The signal was filtered and amplified by the conditioning circuit. The signal was collected by the microcontroller NRF52832 and was sent to the mobile APP. After the signal was preprocessed by the wavelet threshold denoising algorithm in APP, the time and frequency characteristics of the sEMG signal reflecting the functional state of the muscle were extracted. The calculated characteristic parameters was displayed in real time in the application interface. The experimental results show that the system meets the design requirements in analog signal acquisition, digital processing of signals and calculation of characteristic parameters. The system has certain application value.

Variation of neck EMG and mechanical characteristics during the process of cervical traction / 医用生物力学

Objective To observe changes of surface electromyography (sEMG) in cervical traction under different loading weight and at different angles, and compare the muscle activity changes obtained by experiment with simulation results obtained by AnyBody cervical modeling, so as to verify the rationality of the simulation results. Methods Ten young volunteers with supine cervical traction were selected to test the sEMG signals of bilateral sternocleidomastoid (SCM) and upper trapezius (UT) muscles by using the JE-TB0810 surface EMG device. The average EMG (AEMG) and mean power frequency (MPF) were used to analyze the variation patterns of sEMG in cervical spine. Results The AEMG values of SCM and UT muscles increased as the loading weight and traction angles increasing, with a statistically significant difference (P0.05). The experimental results were consistent with muscle force activity characteristics of SCM and UT muscles by modeling and simulation of cervical traction. Conclusions The simulation results are reasonable. The traction weight should be loaded reasonably according to the excitation and fatigue of the cervical muscles in clinic. This can both reach the treatment effect and improve the patient’s comfort, which will provide an important reference for further development and improvement of the cervical traction device.

Electromyographic preactivation pattern of the gluteus medius during weight-bearing functional tasks in women with and without anterior knee pain / Padrão de pré-ativação eletromiográfica do glúteo médio durante atividades funcionais com descarga de peso em mulheres com e sem dor anterior do joelho

BACKGROUND: Proximal factors have been proposed to influence the biomechanics of the patellofemoral joint. A delayed or diminished gluteus medius (GM) activation, before the foot contact on the ground during functional activities could lead to excessive femur adduction and internal rotation and be associated with anterior knee pain (AKP). There are few studies on this topic and the results were inconclusive, therefore, it is necessary to investigate the GM preactivation pattern during functional activities. OBJECTIVE: To compare the GM electromyographic (EMG) preactivation pattern during walking, descending stairs and in single leg jump task in women with and without AKP. METHODS: Nine women clinically diagnosed with AKP and ten control subjects with no history of knee injury participated in this study. We evaluated GM EMG linear envelope before the foot contact on the ground during walking and GM onset time and EMG linear envelope during descending stairs as well as in a single leg vertical jump. Mann-Whitney U tests were used to determine the between-group differences in GM EMG preactivation pattern. RESULTS: No between-group differences were observed in GM linear envelope during walking (P=0.41), GM onset time and linear envelope during descending stairs (P=0.17 and P=0.15) and single leg jump (P=0.81 and P=0.33). CONCLUSIONS: Women with AKP did not demonstrated altered GM preactivation pattern during functional weight bearing activities. Our results did not support the hypothesis that poor GM preactivation pattern could be associated with AKP.

CONTEXTUALIZAÇÃO: Tem sido proposto que fatores proximais influenciam a biomecânica da articulação fêmoro-patelar. Um atraso ou diminuição da ativação do glúteo médio (GM) antes do contato do pé no solo, durante atividades funcionais, poderia levar a adução e rotação interna excessiva do fêmur e provocar a dor anterior do joelho (DAJ). Existem poucos estudos sobre o assunto, e os resultados não foram conclusivos; assim, há necessidade de estudar a pré-ativação do GM durante atividades funcionais. OBJETIVO: Comparar o padrão de pré-ativação eletromiográfica (EMG) do GM durante a caminhada, descida de degraus e salto unipodal entre mulheres com e sem DAJ. MÉTODOS: Nove mulheres com diagnóstico clínico de DAJ e dez mulheres sem história de lesão no joelho participaram do estudo. Avaliou-se a envoltória linear do sinal EMG do GM antes do contato do pé no solo, durante caminhada; o tempo de ativação do GM e a envoltória linear do sinal EMG durante descida de degraus e salto unipodal. Utilizou-se o teste Mann-Whitney para determinar a diferença intergrupos no padrão de pré-ativação EMG do GM. RESULTADOS: Não se encontrou nenhuma diferença intergrupos na envoltória linear do GM durante caminhada (P=0.41), no tempo de ativação e na envoltória linear, durante descida de degraus (P=0.17 e P=0.15) e salto unipodal (P=0.81 e P=0.33). CONCLUSÕES: Mulheres com DAJ não apresentaram alterações significativas no padrão de pré-ativação do GM durante atividades funcionais. Os presentes resultados não sustentam a hipótese de que o pobre padrão de pré-ativação do GM esteja envolvido na DAJ.

Finger Motion Decoding Using EMG Signals Corresponding Various Arm Postures

We provide a novel method to infer finger flexing motions using a four-channel surface electromyogram (EMG). Surface EMG signals can be recorded from the human body non-invasively and easily. Surface EMG signals in this study were obtained from four channel electrodes placed around the forearm. The motions consist of the flexion of five single fingers (thumb, index finger, middle finger, ring finger, and little finger) and three multi-finger motions. The maximum likelihood estimation was used to infer the finger motions. Experimental results have shown that this method can successfully infer the finger flexing motions. The average accuracy was as high as 97.75%. In addition, we examined the influence of inference accuracies with the various arm postures.

A Study on the Decomposition of Surface EMG Signals Based on Second Order Non-stationary Source Separation / 航天医学与医学工程

Objective To investigate the decomposition method of surface EMG(sEMG)signals based on Blind Source Separation and to detect the the motor unit action potential(MUAP)information.Methods Utilizing the sEMG signals recorded at low muscle contraction force(10% MVC),the methods of second order non-stationary source separation(SEONS)and FastICA were explored to analyze the sEMG signals decomposition.Results The experiment results showed that the MUAP information could be acquired by spike detection and pattern recognition after the decomposition of recorded sEMG signals using the proposed algorithm and FastICA method,but a little difference occurred due to the complexity of sEMG signals.Conclusion The non-stationary characteristic of sEMG signals is considered by the SEONS algorithm,and the proposed method can be applied in the sEMG signals decomposition.

A study on the correlations between facial biotype, submentovertex cephalometric measurements and surface EMG activity in patients with facial asymmetry / 대한치과교정학회지

Although the submentovertex radiograph and surface EMG are not often used due to the difficulty of interpretation, they are accepted as useful diagnostic and analytic aids for skeletal asymmetry. There have been reports which state that they were also useful for the evaluation of vertical skeletal relations. The purpose of this study was to evaluate the correlations between EMG data, measurements from submentovertex radiographs, facial types and facial asymmetry following examination of 60 asymmetric patients. The radiographic corpus length were greater in the nonaffected sides (p < 0.001), gonion to interspinosum axis were greater in the affected sides and the mandibular condyle and gonion were located more anteriorly in the non-affected sides than in the affected sides but not significant (p=0.07). The activity of the anterior temporal muscle in rest position was higher in the affected sides than in the non-affected sides (p < 0.01). The activity of the masseter muscle at maximum clenching was found to be nonsignificant but it was higher in the affected sides than in the non-affected sides (p=0.09). There was positive correlation between facial index and the intercondylar axes angle (p < 0.01). There was positive correlation between masseter muscle activity in maximum occlusion and facial index in the affected and non-affected sides (p < 0.05). The results demonstrate that the submentovertex radiograph and EMG can provide useful information for the evaluation of horizontal and vertical skeletal relations.

Quantitative EMG Changes During 12-Week DeLorme's Axiom Strength Training

Strength training is one of the most common exercises practiced in the field of physical therapy or sports training. However, limited methodology is available to evaluate its effect on the target muscle. This study aimed to test the hypothesis that surface electromyographic (EMG) data from both isometric and isotonic exercise can express changes within the muscle during a 12-week strength training program. Ten healthy male volunteer students (5 for training, 5 for controls) from Yonsei University were recruited for evaluation in this study. DeLorme's axiom was practiced for 12 weeks in the dominant elbow flexors and knee extensors of the training group. Tension for 1 repetition maximum and maximal voluntary isometric contraction, and surface EMG information such as the integrated EMG and three variables from the regression line of median frequency (MDF) data were measured at weeks 0, 3, 6, 9, and 12. The limb circumference was measured at weeks 0 and 12. During the strength training, which was enough for the increment of muscle strength and limb circumference, the rectified-integrated EMG and initial MDF increased with a significant linear pattern in both types of contraction. The two surface EMG variables were able to monitor the physiologic muscle changes during the training. Based on these results, we propose that these two surface EMG variables can be used for monitoring electrophysiological changes in the specific muscle that is undergoing the training program, under conditions where the contraction mode for EMG data collection is either static or dynamic.

Comparison Study between Superficial and Deep Acupuncture on the Neck and Shoulder Stiffness-As index of muscle hardness, surface EMG and deep hemodynamics- / 日本温泉気候物理医学会雑誌

We examined the effects of superficial and deep acupuncture on the neck and shoulder stiffness. The aim of this study was 1) to clarify whether muscle hardness and surface EMG under slightly flexed neck position are useful as objective index of the muscle tone 2) to compare the effects of acupuncture in different depths (superficial and deep) on the muscle hardness, surface EMG and deep hemodynamics.<br>10 healthy subjects participated. Two modes of acupuncture, deep muscle stimulation and subcutaneous acupuncture insertion were performed at the neck and shoulder. Both of the superficial and deep acupuncture were left for 10 minutes.<br>As a result, there was a good correlation between muscle hardness and surface EMG under slightly flexed neck position (p<0.01). The integrated EMG was significantly decreased by the superficial acupuncture (p<0.05).<br>On the other hand, muscle hardness was significantly reduced by both of the superficial acupuncture and deep acupuncture (p<0.05).<br>Furthermore, the oxyHb was increased by the superficial acupuncture (p<0.05).<br>These results suggested that the superficial acupuncture has a greater efficiency than the deep acupuncture on neck and shoulder stiffness under slightly flexed neck position.

VALIDITY OF LOCATION OF MUSCULAR UNITS ESTIMATED THROUGH INVERSE ANALYSIS OF SURFACE ELECTROMYOGRAMS / 体力科学

We have developed a method for estimating the depth and intensity of muscular unit represented as equivalent current dipoles by the inverse analysis of surface electromyograms (EMGs) . In this study, the validity of the locations of current dipoles estimated through the inverse analysis was verified by animal experiments. Surface motor unit action potentials (MUAPs) were recorded from the gastrocnemius muscle activated by electrical stimulation at the ventral root of lumbar spinal cord (L4 or L5) of rats. After recording the surface MUAPs for the inverse analysis and glycogen depletion of active muscle fibers by repeated electrical stimulation, periodic acid-Schiff (PAS) staining was used to determine the position of muscle fibers belonging to an active single motor unit. In the results of the inverse analysis, the values of ‘goodness of fit’ between measured and calculated MUAP were 71%, 79% and 85%. Estimated depths of current dipoles ranged from 1.8 mm to 5.9 mm. The locations estimated through the inverse analysis were more medial and shallower than the actual distribution of active muscle fibers determined by PAS staining. These errors were probably caused by the effects of the boundary in the model, the relationship between the measurement area and the location of an active motor unit, and the artifacts such as deformation of the muscle during dissection and freezing.

MUSCULAR UNIT SIZE AND FIBER DENSITY DEDUCED FROM SIMULATION OF INVERSE ANALYSIS OF SURFACE ELECTROMYOGRAMS / 体力科学

The purpose of this study was to noninvasively extract information about the size and muscle fiber density of muscular units through the inverse analysis of surface electromyograms. Surface motor unit action potentials (MUAPs) were recorded with a multi-channel electrode array arranged along the circumference direction of the biceps brachii. The depth and intensity of equivalent current dipoles were estimated through the inverse analysis of surface MUAPs. The simulation of inverse analysis of surface potentials generated by the muscular unit models showed that the relationship between the depth and the intensity depends on the muscular unit size and muscle fiber density.<BR>In the simulation, we systematically varied the model parameters including distance from the skin, radius, and fiber density and used the inverse analysis to estimate the depth and intensity of current dipoles. And, our method to estimate the radius and fiber density of muscular units using estimated depth and intensity is demonstrated. Mean values (± SD) estimated from the surface MUAPs were 3.0±1.8mm for depth and 13.8±32.0nAm for intensity. The estimated distance ranged from slightly less than 1 mm to slightly more than 2 mm. The estimated radius ranged from 1.8 to 4.6 mm and fiber density from 0.7 to 5.4 fibers/mm<SUP>2</SUP>.

Application of improved BP algorithm to surface EMG signal classification / 医疗卫生装备

The application of improved BP neural network together with the wavelet transform to the classification of surface EMG signal is described. The data reduction and preprocessing of the signal are performed by wavelet transform. The network can identify such four kinds of forearm movements with a high accuracy as hand extension, clench fist, forearm pronation and forearm supination. This paper compares the results by standard BP algorithm with that of Bayesian regularization together with LM algorithm. Experimental result shows that the improved BP neural network has a great potential when applied to electromechanical prosthesis control because of its enhanced training speed and identification accuracy.

The sEMG Characteristics of the Lower Limbs Muscles in Stroke Patients / 中国运动医学杂志

Objective To observe the surface electromyogram(sEMG)characteristics of the lower limbs muscles in stroke patients and healthy subjects during the passive and active-assisted anti-resistance movements.Methods Twenty four stroke patients and 17 healthy individuals(control group) participated in this study.sEMG of rectus femoris(RF),vastus lateralis(VL),ventralis medialis(VM)and biceps femoris(BF)was recorded during passive and active-assisted anti-resistance of knee joint in both groups.Average EMG(AEMG),mean power frequency(MPF)and median frequency(MF) were analyzed.Results Multiple factor ANOVA showed that very significant differences in the values of MF,MPF and AEMG between non-paretic and the paretic limbs appeared(P

THERAPEUTIC THERA-BAND EXERCISE ON OSTEOARTHRITIS OF THE KNEE-EFFECTS OF SIMULTANEOUS EXERCISE OF KNEE EXTENSORS AND FLEXORS- / 体力科学

Purpose : We examined the effect of therapeutic exercise on osteoarthritis (OA) of the knee. Objects and Method : We evaluated seven women with bilateral OA of the knees of over Grade I on the Kellgren and Lawrence scale. The patients were instructed in therapeutic exercise for both knees. The exercise was to tie a Thera-Band <SUP>®</SUP> around the leg just above both ankles in the 8 figure, and then, in a sitting position, extend one leg while simultaneously retracting the other, repeating alternatively every 5 seconds. One set consisted of repeating this motion 10 times, and 2 sets were performed per day. Before exercise, 1 month, and 3 months after exercise, we evaluated the effect of this therapy by the JOA score, isokinetic muscle strength of knee extensors and flexors, and surface EMG signals recorded from rectos femoris (RF), vastus medialis (VM), vastus lateralis (VL), and biceps lemons (BF) . The integrated signal, the root mean square (RMS), and the mean power frequency (MPF) parameters were extracted.<BR>Result : The parameters of the JOA score, muscle strength of knee flexors, integrated EMG from RF, VM, VL, and RMS from VM, VL were significantly increased at 3 months after exercise. MPF from VM at 3 months after exercise decreased significantly.<BR>Conclusion : We thought a proper balance of knee extensors and flexors are related to the improvement of symptoms of OA of the knee. The decrease of MPF might suggest the possibility of muscle fiber type change. It is also possible that pain reduction results from the improvement of balance between knee extensors and flexors as well as from the increase of knee joint stability. Therapeutic exercise with the Thera-Band R is extremely easy and is effective in promoting con-tinuous exercise.

Electromyographic Changes Induced by Caloric Stimulation of the Semicircular Canals and by Neck Movement. Investigation of the F wave on the evoked electromyograms of the upper extremity and the surface electromyograms of the posterior cervical region / 全日本鍼灸学会雑誌

We assumed that changes in the excitability of motor nerves play some role in the stiffness of the neck, shoulders, and extremities in patients with vertigo. To obtain a better understanding of this phenomenon, we stimulated the receptors involved in body equilibrium with external stimuli, i.e., 1) caloric stimulation of the semicircular canals and 2) neck movements, and investigated changes in the F wave and the surface electromyogram (S-EMG) of the posterior cervical region.<BR>The subjects were 40 healthy adults. Caloric stimulation of the semicircular canals was performed by infusing15°C water, and changes in the F wave examined. In addition, changes in the S-EMG by stimulation at temperatures of 5°C or 44°C were investigated. We examined changes in the F wave by the neck movements in association with theresults of the blindfold ed vertical writing test. The F wave of a patient with vertigo was also examined.<BR>During vertigo induced by caloric stimulation of the semicircular canals, the excitability of the F wave on both the stimulated and non-stimulated sides increased, the S-EMGs showed decreased excitability on both the stimulated and non-stimulated sides during maximum voluntary contraction in the subject who experienced severe vertigo, nystagmus, and nausea. The changes in the F wave induced by the neck movements were small. However, excitability increased more significantly during posterior flexion than during other movements, and the angle of deviation of the letters written blindly tended to deviate most markedly toward the left during posterior flexion. The F wave of the patient with vertigo showed excitability, but it tended to decrease as the vertigo diminished.<BR>These findings suggest that vertigo is accompanied by changes in the excitability of motor nerves. These changes are somehow related to the muscle stiffening that results from vertigo.

Classification research on surface EMG signal based on fuzzy wavelet packet and decision tree / 医疗卫生装备

This paper introduces a method for feature extraction of surface EMG signal with fuzzy wavelet packet and classification with C4.5 decision tree. The application of the method to the classification of four action EMG signals proves its effectivity and high recognition rate.