Analysis of muscle synergy and muscle functional network at different walking speeds based on surface electromyographic signal / 生物医学工程学杂志

An in-depth understanding of the mechanism of lower extremity muscle coordination during walking is the key to improving the efficacy of gait rehabilitation in patients with neuromuscular dysfunction. This paper investigates the effect of changes in walking speed on lower extremity muscle synergy patterns and muscle functional networks. Eight healthy subjects were recruited to perform walking tasks on a treadmill at three different speeds, and the surface electromyographic signals (sEMG) of eight muscles of the right lower limb were collected synchronously. The non-negative matrix factorization (NNMF) method was used to extract muscle synergy patterns, the mutual information (MI) method was used to construct the alpha frequency band (8-13 Hz), beta frequency band (14-30 Hz) and gamma frequency band (31-60 Hz) muscle functional network, and complex network analysis methods were introduced to quantify the differences between different networks. Muscle synergy analysis extracted 5 muscle synergy patterns, and changes in walking speed did not change the number of muscle synergy, but resulted in changes in muscle weights. Muscle network analysis found that at the same speed, high-frequency bands have lower global efficiency and clustering coefficients. As walking speed increased, the strength of connections between local muscles also increased. The results show that there are different muscle synergy patterns and muscle function networks in different walking speeds. This study provides a new perspective for exploring the mechanism of muscle coordination at different walking speeds, and is expected to provide theoretical support for the evaluation of gait function in patients with neuromuscular dysfunction.

Follow control of upper limb rehabilitation training based on Kinect and NAO robot / 生物医学工程学杂志

Gesture imitation is a common rehabilitation strategy in limb rehabilitation training. In traditional rehabilitation training, patients need to complete training actions under the guidance of rehabilitation physicians. However, due to the limited resources of the hospital, it cannot meet the training and guidance needs of all patients. In this paper, we proposed a following control method based on Kinect and NAO robot for the gesture imitation task in rehabilitation training. The method realized the joint angles mapping from Kinect coordination to NAO robot coordination through inverse kinematics algorithm. Aiming at the deflection angle estimation problem of the elbow joint, a virtual space plane was constructed and realized the accurate estimation of deflection angle. Finally, a comparative experiment for deflection angle of the elbow joint angle was conducted. The experimental results showed that the root mean square error of the angle estimation value of this method in right elbow transverse deflection and vertical deflection directions was 2.734° and 2.159°, respectively. It demonstrates that the method can follow the human movement in real time and stably using the NAO robot to show the rehabilitation training program for patients.

An improved maximal information coefficient algorithm applied in the analysis of functional corticomuscular coupling for stroke patients / 生物医学工程学杂志

The functional coupling between motor cortex and effector muscles during autonomic movement can be quantified by calculating the coupling between electroencephalogram (EEG) signal and surface electromyography (sEMG) signal. The maximal information coefficient (MIC) algorithm has been proved to be effective in quantifying the coupling relationship between neural signals, but it also has the problem of time-consuming calculations in actual use. To solve this problem, an improved MIC algorithm was proposed based on the efficient clustering characteristics of K-means ++ algorithm to accurately detect the coupling strength between nonlinear time series. Simulation results showed that the improved MIC algorithm proposed in this paper can capture the coupling relationship between nonlinear time series quickly and accurately under different noise levels. The results of right dorsiflexion experiments in stroke patients showed that the improved method could accurately capture the coupling strength of EEG signal and sEMG signal in the specific frequency band. Compared with the healthy controls, the functional corticomuscular coupling (FCMC) in beta (14~30 Hz) and gamma band (31~45 Hz) were significantly weaker in stroke patients, and the beta-band MIC values were positively correlated with the Fugl-Meyers assessment (FMA) scale scores. The method proposed in this study is hopeful to be a new method for quantitative assessment of motor function for stroke patients.

Detection of inferior myocardial infarction based on morphological characteristics / 生物医学工程学杂志

Early accurate detection of inferior myocardial infarction is an important way to reduce the mortality from inferior myocardial infarction. Regrading the existing problems in the detection of inferior myocardial infarction, complex model structures and redundant features, this paper proposed a novel inferior myocardial infarction detection algorithm. Firstly, based on the clinic pathological information, the peak and area features of QRS and ST-T wavebands as well as the slope feature of ST waveband were extracted from electrocardiogram (ECG) signals leads Ⅱ, Ⅲ and aVF. In addition, according to individual features and the dispersion between them, we applied genetic algorithm to make judgement and then input the feature with larger degree into support vector machine (SVM) to realize the accurate detection of inferior myocardial infarction. The proposed method in this paper was verified by Physikalisch-Technische Bundesanstalt (PTB) diagnostic electrocardio signal database and the accuracy rate was up to 98.33%. Conforming to the clinical diagnosis and the characteristics of specific changes in inferior myocardial infarction ECG signal, the proposed method can effectively make precise detection of inferior myocardial infarction by morphological features, and therefore is suitable to be applied in portable devices development for clinical promotion.

An automatic pulmonary nodules detection algorithm with multi-scale information fusion / 生物医学工程学杂志

Lung nodules are the main manifestation of early lung cancer. So accurate detection of lung nodules is of great significance for early diagnosis and treatment of lung cancer. However, the rapid and accurate detection of pulmonary nodules is a challenging task due to the complex background, large detection range of pulmonary computed tomography (CT) images and the different sizes and shapes of pulmonary nodules. Therefore, this paper proposes a multi-scale feature fusion algorithm for the automatic detection of pulmonary nodules to achieve accurate detection of pulmonary nodules. Firstly, a three-layer modular lung nodule detection model was designed on the deep convolutional network (VGG16) for large-scale image recognition. The first-tier module of the network is used to extract the features of pulmonary nodules in CT images and roughly estimate the location of pulmonary nodules. Then the second-tier module of the network is used to fuse multi-scale image features to further enhance the details of pulmonary nodules. The third-tier module of the network was fused to analyze the features of the first-tier and the second-tier module of the network, and the candidate box of pulmonary nodules in multi-scale was obtained. Finally, the candidate box of pulmonary nodules under multi-scale was analyzed with the method of non-maximum suppression, and the final location of pulmonary nodules was obtained. The algorithm is validated by the data of pulmonary nodules on LIDC-IDRI common data set. The average detection accuracy is 90.9%.

Detection algorithm of paroxysmal atrial fibrillation with sparse coding based on Riemannian manifold / 生物医学工程学杂志

In order to solve the problem that the early onset of paroxysmal atrial fibrillation is very short and difficult to detect, a detection algorithm based on sparse coding of Riemannian manifolds is proposed. The proposed method takes into account that the nonlinear manifold geometry is closer to the real feature space structure, and the computational covariance matrix is used to characterize the heart rate variability (RR interval variation), so that the data is in the Riemannian manifold space. Sparse coding is applied to the manifold, and each covariance matrix is represented as a sparse linear combination of Riemann dictionary atoms. The sparse reconstruction loss is defined by the affine invariant Riemannian metric, and the Riemann dictionary is learned by iterative method. Compared with the existing methods, this method used shorter heart rate variability signal, the calculation was simple and had no dependence on the parameters, and the better prediction accuracy was obtained. The final classification on MIT-BIH AF database resulted in a sensitivity of 99.34%, a specificity of 95.41% and an accuracy of 97.45%. At the same time, a specificity of 95.18% was realized in MIT-BIH NSR database. The high precision paroxysmal atrial fibrillation detection algorithm proposed in this paper has a potential application prospect in the long-term monitoring of wearable devices.

Detection of inferior myocardial infarction based on densely connected convolutional neural network / 生物医学工程学杂志

Inferior myocardial infarction is an acute ischemic heart disease with high mortality, which is easy to induce life-threatening complications such as arrhythmia, heart failure and cardiogenic shock. Therefore, it is of great clinical value to carry out accurate and efficient early diagnosis of inferior myocardial infarction. Electrocardiogram is the most sensitive means for early diagnosis of inferior myocardial infarction. This paper proposes a method for detecting inferior myocardial infarction based on densely connected convolutional neural network. The method uses the original electrocardiogram (ECG) signals of serially connected Ⅱ, Ⅲ and aVF leads as the input of the model and extracts the robust features of the ECG signals by using the scale invariance of the convolutional layers. The characteristic transmission of ECG signals is enhanced by the dense connectivity between different layers, so that the network can automatically learn the effective features with strong robustness and high recognition, so as to achieve accurate detection of inferior myocardial infarction. The Physikalisch Technische Bundesanstalt diagnosis public ECG database was used for verification. The accuracy, sensitivity and specificity of the model reached 99.95%, 100% and 99.90%, respectively. The accuracy, sensitivity and specificity of the model are also over 99% even though the noise exists. Based on the results of this study, it is expected that the method can be introduced in the clinical environment to help doctors quickly diagnose inferior myocardial infarction in the future.

Effectiveness analysis of muscle fatigue in rehabilitation based on surface electromyogram / 生物医学工程学杂志

Muscle fatigue has widespread application in the field of rehabilitation medicine. The paper studies the muscle fatigue using surface electromyogram (sEMG) in the background of rehabilitation training system. The sEMG and ventilatory threshold of vastus lateralis, rectus femoris and erector spinae are collected synchronously and the electromyogram fatigue threshold (EMG ) of different sEMG was analyzed by increasing load cycling experiments of 10 healthy subjects. This paper also analyzes the effect of isotonic and isometric contraction on EMG . Results showed that the appeared time of EMG was earlier than that of ventilatory threshold in the incremental load cycling. While the differences were subtle and EMG was verified to be effective. EMG has been proven effective for different muscle contraction by comparing the EMG of vastus lateralis and erector spinae. EMG could be used to keep muscle injuries from overtraining in the process of rehabilitation. Therefore, EMG has a great significance for femoral shaft fractures's fatigue monitoring in rehabilitation training.

Effect of long-chain non-coding RNA TUG1 on radiosensitivity of human cervical cancer XB1702 cells by adsorption of miR-145 / 中华放射肿瘤学杂志

Objective@#To evaluate the effect of long-chain non-coding RNA TUG1 on the radiosensitivity of cervical cancer cells and explore its underlying mechanism.@*Methods@#The expression of TUG1 and miR-145 in cervical cancer cells XB1702 and normal endometrial stromal cells (ESCs) was detected by qRT-PCR. The transfected si-NC, transfected si-TUG1, transfected si-NC combined with irradiation, transfected si-TUG1 combined with irradiation, si-TUG1 and anti-miR-NC co-transfected and, si-TUG1 and anti-miR-145 co-transfected groups were established, which were transfected into XB1702 cells by liposome method. The survival fraction of each group was detected by colony formation assay. The cell apoptosis of each group was detected by flow cytometry. The fluorescence activity of each group was assessed by dual luciferase reporter gene assay.@*Results@#Compared with the normal ESCs, the expression of TUG1 was significantly up-regulated, whereas that of miR-145 was significantly down-regulated in the cervical cancer cells XB1702. Silencing TUG1 significantly increased the survival fraction of XB1702 cells, promoted cell apoptosis and enhanced the radiosensitivity of irradiation to XB1702 cells. TUG1 could target and regulate the expression of miR-145. Suppressing miR-145 reversed the silencing effect of TUG1 on inhibiting proliferation, accelerating apoptosis promotion and enhancing sensitization of XB1702 cells.@*Conclusions@#Silencing long-chain non-coding RNA TUG1 can enhance the radiosensitivity of cervical cancer cells. The mechanism may be related to targeting miR-145, which will provide a target for radiotherapy of cervical cancer.

Coronary vessel intimal sequence extraction based on prior boundary constraints in optical coherence tomography image / 生物医学工程学杂志

Optical coherence tomography (OCT) is a new technique applied in cardiovascular system. It can detect vessel intimal, small structure of plaque surface and discover small lesions with its high axial resolution and quantification character. Especially with the application of OCT in characterization of coronary atherosclerotic plaque, diagnosis and treatment strategy making, optimizing percutaneous coronary intervention therapy and assessment after stent planting make the OCT become an efficient tool for cardiovascular disease diagnosis and treatment. This paper presents a novel coronary vessel intimal sequence extraction method based on prior boundary constraints in OCT image. On the basis of conventional Chan-Vese model, we modified the evolutionary weight function to control the evolutionary rate of boundary by adding local information of boundary curve. At the same time, we added the gradient energy term and intimal boundary constraint term based on priori boundary condition to further control the evolutionary of boundary curve. At last, coronary vessel intimal is extracted in a sequence way. The comparison with vessel intimal, manual segmented by clinical scientists (golden standard), indicates that our coronary vessel intimal extraction method is robust to intimal boundary blur, distortion, guide wire shadow and plaque disturbs. The results of this study can be applied to clinical aid diagnosis and precise diagnosis and treatment.

An echo state network algorithm based on recursive least square for electrocardiogram denoising / 生物医学工程学杂志

Electrocardiogram (ECG) is easily submerged in noise of the complex environment during remote medical treatment, and this affects the intelligent diagnosis of cardiovascular diseases. Considering this situation, this paper proposes an echo state network (ESN) denoising algorithm based on recursive least square (RLS) for ECG signals. The algorithm trains the ESN through the RLS method, and can automatically learn the deep nonlinear and differentiated characteristics in the noisy ECG data, and then the network can use these characteristic to separate out clear ECG signals automatically. In the experiment, the proposed method is compared with the wavelet transform with subband dependent threshold and the S-transform method by evaluating the signal-to-noise ratio and root mean square error. Experimental results show that the denoising accuracy is better and the low frequency component of the signal is well preserved. This method can effectively filter out complex noise and effectively preserve the effective information of ECG signals, which lays a foundation for the recognition of ECG signal feature waveform and the intelligent diagnosis of cardiovascular disease.

Changes of Th17 cytokine in human bronchial epithelial cells induced by coke oven emission / 中国药理学与毒理学杂志

OBJECTIVE To find the infla mmation bio markers induced by coke oven e missions (COE),we investigated the changes of T helper 17 (Th17 )cytokines in hu man bronchial epithelial (16HBE)cells.METHODS 16HBE cells were exposed to organic extracts of COE collected fro m co-king plant at the concentrations of 5,10 and 20 mg·L -1 for 24 h or 5 d to establish short-term and long-term cell models,respectively.Cell viability was measured by MTT assay and infla mmatory da mage was assessed by lactate dehydrogenase assay (LDH).The cytokines in culture supernatant sa mples was detected by co mmercial hu man Th17 cytokine panel kit.RESULTS COE Can induce infla mmation in COE 20 mg·L -1 group and no expression on IL-17 F and IL-1 β.The concentration of IL-10 was 1 .25 ± 0.54,1 .39 ±0.13 and (1 .90 ±0.73)pg·mL -1 in COE 5,10 and 20 mg·L -1 group showing good con-centration-effect relationship (r=0.98,P <0.05 ).IL-23 expression was found only higher at 10 and 20 mg·L -1 and the concentrations were 3.38 ±3.90 and (1 .74 ±2.00 )pg·mL -1 ,respectively.In 16HBE cells treated by COE for 5 d,elevated expression of IL-17A was found in COE 5 and 10 mg·L -1 group,and there was statistically sigificant difference between COE 10 mg·L -1 and DMSO group (P<0.05).Elevated concentration of IL-17F of 10.2 ±1 1 .78 and (6.79 ±7.84)pg·mL -1 was found in COE 5 and 10 mg·L -1 group.The concentration of IL-10 was 1 .71 ±0.02,1 .49 ±0.25 and (2.82 ± 0.33)pg·mL -1 in COE 5,10 and 20 mg·L -1 group,respectively.We found increased IL-1 βexpression with concentration of 2.72 ±0.62,2.25 ±0.33 and (0.93 ±0.21 )pg·mL -1 in COE 5,10 and 20 mg·L -1 group with negative dose-response relationship.We also found more elevated TNF-αlevels in the 5 d than in the 24 h model with no COE specific relationship.CONCLUSION COE induces expression changes of Th17 cytokines profile in 16HBE cells,including IL-23 and IL-1 βfor early and long-term infla mmation,respectively.IL-10 may be a candidate marker for population study on COE induced infla mmatory injury.

An improved wavelet threshold algorithm for ECG denoising / 生物医学工程学杂志

Due to the characteristics and environmental factors, electrocardiogram (ECG) signals are usually interfered by noises in the course of signal acquisition, so it is crucial for ECG intelligent analysis to eliminate noises in ECG signals. On the basis of wavelet transform, threshold parameters were improved and a more appropriate threshold expression was proposed. The discrete wavelet coefficients were processed using the improved threshold parameters, the accurate wavelet coefficients without noises were gained through inverse discrete wavelet transform, and then more original signal coefficients could be preserved. MIT-BIH arrythmia database was used to validate the method. Simulation results showed that the improved method could achieve better denoising effect than the traditional ones.

Monitoring the Air Sterilization Effect in Operating Room by Different Sterilization Methods / 中华医院感染学杂志

OBJECTIVE To compare the air sterilization effect of in operating room used by different air sterilization methods.METHODS Four types sterilization methods were used to operating room air.Then sampling monitoring and evaluation were done.RESULTS The qualification rate of air sterilization were 79.17%,62.79%,79.63%,97.22% in peroxyacetic acid fumigating,simple ultraviolet radiation,peroxyacetic acid fumigating combined with simple ultraviolet radiation,ultraviolet light circulation wind air sterilization machine,respectively.The sterilization effect of ultraviolet light circulation wind was better than the others.CONCLUSIONS Ultraviolet light circulation wind air sterilization machine can be used to air sterilization in non-laminar air flow purify operating room.

A survey on the relationship between trace elements and blood lipids and glucose in Shanghai adults / 中华临床营养杂志

Objective To study the relationship between trace elements and blood lipids and glucose in Shanghai adults. Methods Totally 245 subjects aged above 18 years from two communities in Shanghai were en-rolled into this study. Blood trace elements (Fe, Zn, Cu, Mg, Pb, Mn, and Cd) were examined with atom ab-serption spectrophotometry. Body mass index (BMI), waist hip rate (WHR), and blood pressure (SBP, DBP)were also determined. Results Compared with the normal control group, plasma Fe and Mn levels were signifi-cantly lower while Zn and Zn/Cu levels were significantly higher in hyperlipemia group (P <0.05 or P <0. 01 ) ;plasma Zn, Zn/Cu, and Mn levels were significantly lower while Cu and Pb levels were significantly higher in dia- betes mellitus group (P <0. 05 or P <0. 01 ) . A tendency of lower Mg and higher Cd levels were also found in both disease groups, but there were no statistical significance ( P >0. 05 ). Conclusions The metabolism of trace elements is abnormal in patients with hyperlipemia and diabetes mellitus. Intervention of these trace elements disor-der may be valuable in the prevention and treatment of these diseases.

Association between the nutrition statuses of thiamine and riboflavin and the antioxidant capacity in the middle-aged and elderly / 中华临床营养杂志

Objective To investigate the nutrition statuses of thiamine and riboflavin and their relationship with the antioxidant capacity and blood glucose and lipids levels in the middle-aged and elderly. Methods Totally 314 subjects aged above 40 years old from communities in Shanghai were enrolled. The 3-day survey of 24-hour's diet recall was made to evaluate the daily nutrient intakes using a nutrition assessment software provided by CDC China. Thiamine and riboflavin levels were detected by urine load test. Fasting blood glucose ( FBG), total choles-terol (TC), triglyceride (TG), superoxide dismutase (SOD) activity and malondialdehyde (MDA) were deter-mined by commercial kits. Results The average daily intakes of thiamine and riboflavin were (0. 82 + 0. 36) and (0. 91 +0.48) rag, respectively. The middle-aged and elderly whose intakes of thiamine and riboflavin reached recommended nutrient intake (RNI) level accounted for 11.8% and 17.2%, while those lower than 60% RNI ac-counted for 51.3% and 49. 4%, respectively. Urine load test showed the deficiency rates of thiamine and ribofla-vin were 65.0% and 58.6%, respectively. Compared with the normal group, plasma MDA, FBG, TC, and TG levels progressively increased and SOD activity decreased in insufficient and deficient groups; the plasma MDA, FBG, and TC levels were significantly different between normal group and thiamine deficient group ( P < 0. 05 ).The FBG and TC levels were negatively correlated with the status of thiamine ( r = - 0. 246, r = - 0. 154, P <0. 05). The MDA and TG levels were negatively correlated with the status of riboflavin ( r = - 0. 136, r =-0. 297, P <0. 05). Conclusions The nutrition statuses of thiamine and riboflavin are poor in the middle-aged and elderly in Shanghai. The nutritional statuses of thiamine and riboflavin are positively correlated with the antioxi- dant capacities and are negatively correlated with the level of FBG, TC, and TG.