bluuebunny/crossref_metadata_2025_split huggingface dataset:
Local concentric muscle fatigue of the ankle dorsiflexors and plantar flexors: A reproducibility study
Authors: Mattes Klaus , Eldin Ali Hazzaa Walaa , Schaffert Nina , Manzer Stefanie 
Published: June 2015

BACKGROUND: Fatigue due to running or local muscle exhaustion is a causative factor for running injuries. Standardized local muscle fatigue can be produced and assessed with isokinetic devices. OBJECTIVE: To examine the absolute and relative reproducibility of local muscle fatigue of the ankle dorsiflexors (DF) and plantar flexors(PF). METHODS: Using a test-retest design, 29 male runners (height: 181.4 ± 4.7 cm, mass: 79.4 ± 9.3 kg, age: 26.6 ± 4.3 years) were twice assessed, isometrically and isokinetically, at 60°/s. Reproducibility was determined by an intraclass correlation coefficient (ICC) and the Bland-Altmann method. RESULTS: For the isometric test, the ICC values ranged from 0.90-0.99, whereas for the isokinetic fatigue protocol and index, they ranged from 0.87-0.97 and 0.76-0.96, respectively. Absolute reproducibility of the PM in the isometric test was 3.1% and 6.4%, for the DF and PF, respectively. The mean of the PM in the isokinetic fatigue protocol was 6.2% and 10.7% and in the fatigue index 12.3% and 21.8%, respectively. CONCLUSION: Using the protocol and instrument described in this paper, local muscle fatigue of the ankle DF and PF may be reproducibly measured.
Relationship between lower extremity isokinetic strength and anaerobic power in weightlifters, basketball and soccer players
Authors: Harbili Sultan 
Published: June 2015

BACKGROUND: Little is known about the comparative relationships between knee muscles strength and anaerobic power in weightlifters, basketball and soccer players, popular sports that rely on lower extremity muscles strength. METHODS: Ten weightlifters, 12 basketball and 19 soccer players participated in the study. Concentric peak torque of hamstring (H) and quadriceps (Q) of the dominant (D) and non-dominant leg (ND) was evaluated at 60 and 240°/s. Subjects also performed Wingate Anaerobic Test(WAnT) 48 h after isokinetic measurements. RESULTS: Normalized peak moment of the hamstring (NPMh) of D in soccer players was significantly greater than in basketball players and weightlifters at 60 and 240°/s. At 60°/s, weightlifters presented a greater NPMq when compared to soccer players in D. Significant correlations were observed between NPMq of both legs and peak and mean power at 60 and 240°/s in basketball. In soccer, significant correlations were found between the bilateral NPM of both muscles and the peak and mean power at 240°/s. CONCLUSIONS: Knee flexion strength plays a more decisive role in soccer due to the fast movement pattern while knee extension strength is more important in basketball and weightlifting due to vertical movement patterns.
Comparison of muscle activation of hip belt squat and barbell back squat techniques
Authors: Gulick Dawn T. , Fagnani James A. , Gulick Colleen N. 
Published: June 2015

BACKGROUND: Hip belt squats are believed to have been introduced in 1970. By removing the load from the shoulders and upper trapezius, the hip belt squat places emphasis on the legs with less load on the spine. No peer-reviewed research exists on the muscle recruitment patterns of a hip belt squat, or how it compares in muscle activation to other squatting activities. OBJECTIVE: The purpose of the study was to determine lower extremity muscle activation in a hip belt squat (SquatMax = MD) in comparison with a barbell back squat. METHODS: Thirteen participants performed four repetitions of an 8-RM squat using three different techniques: hip belt squat without a band, hip belt squat with a band, and barbell back squat. Electromyographic data were collected from six muscles: quadriceps, biceps femoris, hip adductors, hip abductors, gluteus maximus, and gastrocnemius. RESULTS: ANOVA revealed no significant difference in muscle activity between devices. The only muscle group statistically different between genders was the gastrocnemius (p = 0.04). Hip adductor activity was lowest and hip abductor activity was highest when performing a hip belt squat with the band for both genders. Likewise, the adductor to hamstring ratio was lowest with the hip belt squat. CONCLUSIONS: Given the lack of significant difference in the muscle activity between the squat techniques, one needs to look at other attributes to determine both the scientific and, consequently, the practical value. Given the placement of the belt around the pelvis, one positive attribute for the hip belt squat is the ability to unload the shoulders and spine. Another positive attribute for the hip belt squat is the higher hip abductor to adductor ratio. This could be very important for injury prevention and patella tracking. While the back squat has slightly higher hamstring recruitment, which is important in ACL injury prevention, the hip belt squat may address this by offsetting the free weight with the use of an additional band. If a free weight hip belt squat device is available, it may be a better alternative to the traditional barbell squat technique.
Effects of six weeks of resistance exercise with reciprocal contractions on knee extensors neuromuscular performance: Randomized controlled trial
Authors: Cardoso Euler , Bottaro Martim , Rodrigues Pâmella , Souza Igor Eduardo , Durigan João , Lima Ricardo Moreno , Júnior Silvio Assis Oliveira , Carregaro Rodrigo Luiz 
Published: June 2015

BACKGROUND: Studies have shown that reciprocal exercise using a pre-activation of antagonist muscles may increase the agonist neuromuscular performance. OBJECTIVE: To compare the efficiency of two modalities of resistance training (with and without antagonist muscle pre-activation) during a six week program on knee extension neuromuscular performance of healthy men. METHODS: Forty-nine men were randomly assigned into two groups: 1) reciprocal training: REC - one concentric knee flexion immediately followed by one concentric knee extension, and 2) control: CON - one concentric knee extension exercise, without pre-activation. Both training modes were characterized by three sets of 10 repetitions at 60°/s, 2 days/week. Knee extensor peak moment (PM), load range (LR), electromyographic activity (EMG) of the vastus medialis (VM), rectus femoris(RF), and biceps femoris (BF) co-activation were assessed pre and post 6 weeks of training. A 2 × 2 mixed factor ANOVA was applied to evaluate differences between variables. RESULTS: Significant increases were found for PM between pre and post-evaluations for both groups. In relation to VM and RF activation, co-activation (BF/VM and BF/RF) and LR, no significant differences between groups and moments were found. CONCLUSION: In view of the results further research is indicated in order to examine the utility of longer programs in positively affecting antagonist muscle co-activation as well as in elucidating its clinical effects in individuals with musculoskeletal dysfunction.
Identification of heart disease-prone personality using oscillometric blood pressure measurements
Authors: Jung Seungah , Shin Youngsuk 
Published: June 2015

BACKGROUND: By using the conventional method of measuring two-points (systolic and diastolic) blood pressure, it is difficult to differentiate a heart disease-prone personality from normals. Recently, an oscillometric method that reflects the personalized trait of blood pressure was developed by one author. OBJECTIVE: By using this new measurement technique, this study intended to test the possibility of differentiating a heart disease-prone personality (type A or type D) from normal people. METHODS: TPA scale in MMPI-2 and DS14 were used for screening type A and D. Oscillometric waveforms created by the cuff pressure were segmented into window blocks based on a single beat at a minimum, allowing this method to extract maximal top and bottom amplitudes in each window block. Then, a spectrogram using a short-time Fourier transform was applied to discriminate between character types in extracted blood pressure patterns with linear discriminant analysis. RESULTS: Compared to a normal personality, type A and type D personalities displayed a lower frequency response on STFT with maximum negative amplitudes than normals. In particular, the type D personality showed a lower frequency response than the type A personality. CONCLUSION: These results could provide a new qualitative method for measuring different biological indices between type A or D personalities and normals.
BP neural network tuned PID controller for position tracking of a pneumatic artificial muscle
Authors: Fan Jizhuang , Zhong Jun , Zhao Jie , Zhu Yanhe 
Published: June 2015

BACKGROUND: Although Pneumatic Artificial Muscle (PAM) has a promising future in rehabilitation robots, it's difficult to realize accurate position control due to its highly nonlinear properties. OBJECTIVE: This paper deals with position control of PAM. METHODS: To describe the hysteresis inside PAM, a polynomial based phenomenological function is developed. Based on the phenomenological model for PAM and analysis of pressure dynamics within PAM, an adaptive cascade controller is proposed. Both outer loop and inner loop employ BP Neural Network tuned PID algorithm. The outer loop is to handle high nonlinearities and unmodeled dynamics of PAM, while the inner loop is responsible for nonlinearities caused by pressure dynamics. RESULTS: Experimental results show high tracking accuracy as compared with a convention PID controller. CONCLUSION: The proposed controller is effective in improving performance of PAM and will be implemented in a rehabilitation robot.
A complexity-efficient and one-pass image compression algorithm for wireless capsule endoscopy
Authors: Liu Gang , Yan Guozheng , Zhao Shaopeng , Kuang Shuai 
Published: June 2015

BACKGROUND: As an important part of the application-specific integrated circuit (ASIC) in wireless capsule endoscopy (WCE), the efficient compressor is crucial for image transmission and power consumption. OBJECTIVE: In this paper, a complexity-efficient and one-pass image compression method is proposed for WCE with Bayer format images. The algorithm is modified from the standard lossless algorithm (JPEG-LS). METHODS: Firstly, a causal interpolation is used to acquire the context template of a current pixel to be encoded, thus determining different encoding modes. Secondly, a gradient predictor, instead of the median predictor, is designed to improve the accuracy of the predictions. Thirdly, the gradient context is quantized to obtain the context index (Q). Eventually, the encoding process is achieved in different modes. RESULTS: The experimental and comparative results show that our proposed near-lossless compression method provides a high compression rate(2.315) and a high image quality (46.31 dB) compared with other methods. CONCLUSION: It performs well in the designed wireless capsule system and could be applied in other image fields.
Research on an anti-motion interference algorithm of blood oxygen saturation based on AC and DC analysis
Authors: Yan Jiayun , Bin Guangyu 
Published: June 2015

BACKGROUND: There is an urgent need for blood oxygen saturation(SpO2) tests when participants are ambulatory, as in daily activity monitoring, sleep monitoring, or even athletes' cardiovascular function tests. In such situations, measuring equipment needs to be wearable. This restricts the processor volume, and the corresponding algorithm should be microprocessor compatible. OBJECTIVE: This article proposes an anti-motion interference blood oxygen saturation algorithm for the microcontroller based on AC and DC analysis, named de-trended FFT. METHODS: An experiment was conducted to compare the de-trended FFT algorithm with two other algorithms commonly used in the time and frequency domains. In the experiment, participants' oxygen saturation levels were calculated from Photoplethysmography (PPG) signals that were recorded continuously. Meantime, five types of hand motions were conducted, including hand trembling movements, horizontal hand movements, vertical hand movements, finger tapping, and finger bending, with each state lasting 2 minutes. RESULTS: Results show significant performance of de-trended FFT in SpO2 calculation (P < 0.05), in both accuracy and stability. CONCLUSION: De-trended FFT stands out in both mean deviation and variance by eliminating trending influence when compared with the other two algorithms. The motion interference's influence on SpO2 calculation mainly comes from the AC component, not the DC.
Can continuous scans in orthogonal planes improve diagnostic performance of shear wave elastography for breast lesions?
Authors: Yang Pan , Peng Yulan , Zhao Haina , Luo Honghao , Jin Ya , He Yushuang 
Published: June 2015

BACKGROUND: Static shear wave elastography (SWE) is used to detect breast lesions, but slice and plane selections result in discrepancies. OBJECTIVE: To evaluate the intraobserver reproducibility of continuous SWE, and whether quantitative elasticities in orthogonal planes perform better in the differential diagnosis of breast lesions. METHOD: One hundred and twenty-two breast lesions scheduled for ultrasound-guided biopsy were recruited. Continuous SWE scans were conducted in orthogonal planes separately. Quantitative elasticities and histopathology results were collected. Reproducibility in the same plane and diagnostic performance in different planes were evaluated. RESULTS: The maximum and mean elasticities of the hardest portion, and standard deviation of whole lesion, had high inter-class correlation coefficients (0.87 to 0.95) and large areas under receiver operation characteristic curve (0.887 to 0.899). Without loss of accuracy, sensitivities had increased in orthogonal planes compared with single plane(from 73.17% up to 82.93% at most). Mean elasticity of whole lesion and lesion-to-parenchyma ratio were significantly less reproducible and less accurate. CONCLUSION: Continuous SWE is highly reproducible for the same observer. The maximum and mean elasticities of the hardest portion and standard deviation of whole lesion are most reliable. Furthermore, the sensitivities of the three parameters are improved in orthogonal planes without loss of accuracies.
The study of medical image enhancement based on curvelet\footnote{This work is supported by Natural Science Foundation of Heilongjiang Province (No. GFQQ2440501411).}
Authors: Guo Qi , Su Xiaoyun 
Published: June 2015

BACKGROUND: Breast cancer is a tumor that begins in the breast tissue and is largely identified through X-ray imaging; however, human tissue, illumination, noise and other factors make the image's calcifications and masses unclear, which in turn affects the doctors' identification of lesions and normal tissue through X-ray imaging. Therefore, the rate of misdiagnoses can be reduced through the enhancement of X-ray images that make the images' calcifications and masses more prominent. OBJECTIVE: Enhancing the breast image would highlight the calcifications and masses. METHODS: One such way to do so is to use a curvelet that can detect curves and can, therefore, enhance the tumor characteristics. Essentially, existing methods perform a curvelet transform on each sub-image simultaneously; as the curvelet is based on the Radon transform, it involves complex computation and can easily result in difficulties. Based on this information, this article improved the algorithm that detects edges by curvelet and refines edges by wavelet. Simulation experiments using mammography X-ray images are implemented through Matlab. RESULTS: The results suggest that, after implementation of the improved algorithm, the image's edges and textures are clear, the calcifications are independent, and there is no caking. CONCLUSIONS: The curvelet method is imporved in efficacy with respect to the wavelet method.
Feature study of hysterical blindness EEG based on FastICA with combined-channel information
Authors: Qin Xuying , Wang Wei , Hu Lintao , Wang Xu , Yuan Xiaojie 
Published: June 2015

BACKGROUND: An appropriate feature study of hysteria electroencephalograms (EEG) would provide new insights into neural mechanisms of the disease, and also make improvements in patient diagnosis and management. OBJECTIVE: The objective of this paper is to provide an explanation for what causes a particular visual loss, by associating the features of hysterical blindness EEG with brain function. METHODS: An idea for the novel feature extraction for hysterical blindness EEG, utilizing combined-channel information, was applied in this paper. After channels had been combined, the sliding-window-FastICA was applied to process the combined normal EEG and hysteria EEG, respectively. Kurtosis features were calculated from the processed signals. As the comparison feature, the power spectral density of normal and hysteria EEG were computed. RESULTS: According to the feature analysis results, a region of brain dysfunction was located at the occipital lobe, O1 and O2. Furthermore, new abnormality was found at the parietal lobe, C3, C4, P3, and P4, that provided us with a new perspective for understanding hysterical blindness. CONCLUSIONS: Indicated by the kurtosis results which were consistent with brain function and the clinical diagnosis, our method was found to be a useful tool to capture features in hysterical blindness EEG.
Changes of pelvis control with subacute stroke: A comparison of body-weight- support treadmill training coupled virtual reality system and over-ground training
Authors: Mao Yurong , Chen Peiming , Li Lifang , Li Le , Huang Dongfeng 
Published: June 2015

BACKGROUND: Gait recovery is very important to stroke survivors to regain their independence in activity of daily life. OBJECTIVE: This study aimed to investigate the effects of virtual reality (VR) coupled body weight support treadmill training (BWSTT) on pelvic control at the early stage of stroke. METHODS: Kinematic and kinetic changes of pelvic motion were evaluated by a 3D gait analysis system and were compared to the results from over-ground walking training. Twenty-four patients having unilateral hemiplegia with subacute stroke were recruited to a VR coupled BWSTT group (n= 12) and a conventional therapy (CT) group (n= 12). Both of the groups received training of 20-40 min/day, 5 days/week, for 3 weeks. RESULTS: The results showed the tilt of pelvis in sagittal plane improved significantly (P= 0.038) after treatment in the BWSTT+VR group, in terms of decreased amplitude of anterior peak (mean, from 10.99° to 6.25°), while there were no significant differences in the control group. CONCLUSION: The findings suggested that VR coupled BWSTT gait training could decrease anterior tilt of pelvis in early hemiparetic persons following a modest intervention dose, and the training may have advantages over conventional over-ground gait training and can assist the therapists in correcting abnormal gait pattern of stroke survivors.
Computer-aided King classification of scoliosis
Authors: Zhang Junhua , Li Hongjian , Lv Liang , Shi Xinling , Zhang Yufeng 
Published: June 2015

OBJECTIVE: Surgical planning for scoliosis relies on the classification of spinal curve pattern. The widely used King classification is subject to human measurement and judgment errors. To reduce the variability of King classification, a computer-aided method is proposed and its reliability is evaluated in this study. METHODS: At the first step, endplate inclination and position of each vertebra are measured by a computerized system on the posteroanterior radiograph. Based on these measurements, the apical and end vertebrae are identified and then the Cobb angles are calculated automatically. The system subsequently classifies the curve types automatically based on the computerized Cobb measurements, the vertebral inclination, and the analysis of the relationship between the center sacral vertical line, and the apical lumbar vertebra. Five observers participated in the experiments. The kappa statistic was used to evaluate the variability. RESULTS: Classifications of 105 scoliotic cases by the five observers showed that with the aid of our system, the average intraobserver and interobserver kappa values improved from 0.75 to 0.90 and from 0.66 to 0.86, respectively. CONCLUSION: Results indicate that the proposed computerized system can assist a surgeon with the King classification of scoliosis.
Android based self-diagnostic electrocardiogram system for mobile healthcare
Authors: Choo Kan-Yeep , Ling Huo-Chong , Lo Yew-Chiong , Yap Zuo-Han , Pua Jun-Sheng , Phan Raphael C.-W. , Goh Vik-Tor 
Published: June 2015

BACKGROUND: Cardiovascular diseases are the most common cause of death worldwide and are characterized by arrhythmia (i.e. irregular rhythm of heartbeat). Arrhythmia occasionally happens under certain conditions, such as stress. Therefore, it is difficult to be diagnosed using electrocardiogram (ECG) devices available in hospitals for just a few minutes. Constant diagnosis and monitoring of heartbeat is required to reduce death caused by cardiovascular diseases. OBJECTIVE: Mobile healthcare system has emerged as a potential solution to assist patients in monitoring their own heart condition, especially those who are isolated from the reference hospital. This paper proposes a self-diagnostic electrocardiogram system for mobile healthcare that has the capability to perform a real-time ECG diagnostic. METHODS: The self-diagnostic capability of a real-time ECG signal is achieved by implementing a detrended fluctuation analysis (DFA) method. The result obtained from DFA is used to display the patient's health condition on a smartphone anytime and anywhere. If the health condition is critical, the system will alert the patient and his medical practitioner for further diagnosis. RESULTS: Experimental results verified the validity of the developed ECG diagnostic application on a smartphone. CONCLUSION: The proposed system can potentially reduce death caused by cardiovascular diseases by alerting the patient possibly undergoing a heart attack.
Detection of genioglossus myoelectric activity using ICA of multi-channel mandible sEMG
Authors: Song Tianyi , Meng Baowen , Chen Baoming , Zhao Di , Cao Zhengtao , Ye Jingying , Yu Mengsun 
Published: June 2015

BACKGROUND: Genioglossus myoelectric activity is of great significance in evaluating clinical respiratory function. However, there is a tradeoff in genioglossus EMG measurement with respect to accuracy versus convenience. OBJECTIVE: This paper presents a way to separate the characteristics of genioglossus myoelectric activity from multi-channel mandible sEMG through independent component analysis. METHODS: First, intra-oral genioglossus EMGgenioglossus EMG and three-channel mandible sEMG were recorded simultaneously. The FastICA algorithm was applied to three independent components from the sEMG signals. Then the independent components with the intra-oral genioglossus EMG were compared by calculating the Pearson correlation coefficient between them. RESULTS: An examination of 60 EMG samples showed that the FastICA algorithm was effective in separating the characteristics of genioglossus myoelectric activity from multi-channel mandible sEMG. The results of analysis were coincident with clinical diagnosis through intra-oral electrodes. CONCLUSIONS: Genioglossus myoelectric activity can be evaluated accurately by multi-channel mandible sEMG, which is non-invasive and easy to record.