Technology and Health Care - Volume 25, issue S1

Authors: Yang, Shuo | Qiao, Yanyun | Wang, Lei | Hao, Pengru

Article Type: Research Article

Abstract: BACKGROUND: Mental fatigue caused by continuous cognitive tasks represents one of the most worrying modern health problems. Event Related Potential (ERP) P300 is thought to be associated with cognitive function. OBJECTIVE: This study aimed at characterizing the neural activity correlated with the attentional processes and exploring a novelty method which combine the magnetic stimulation and acupoint to relieve mental fatigue caused by continuous cognitive tasks. METHODS: P300 (P3a and P3b) were extracted at three points: when subjects felt relaxed, at the point of mental fatigue, and after the subjects were stimulated at acupoints. …The amplitudes and latencies of P3a and P3b were analyzed statistically. RESULTS: Among the four features (P3a amplitude, P3a latency, P3b amplitude, and P3b latency), only P3b amplitude was found to have a significant difference between the resting state and the mental fatigue state. And P3b amplitude significantly increased after magnetic stimulation at the acupoints. CONCLUSIONS: Subjects experiencing mental fatigue demonstrated a significant decrease in P3b amplitude in the parietal region, suggesting attenuation of resource allocation for selective attention. P3b amplitude significantly increased after magnetic stimulation at acupoints indicating that this strategy can be used to improve selective attention and relieve mental fatigue. Show more

Keywords: Mental fatigue, magnetic stimulation, Event Related Potential, P300

DOI: 10.3233/THC-171318

Citation: Technology and Health Care, vol. 25, no. S1, pp. 157-165, 2017

Authors: Ding, Xiang | Liu, Wenli | Zhang, Jiyan | Zhao, Liangliang

Article Type: Research Article

Abstract: Accurate electrophysiological diagnosis relies on high precision and well calibrated instruments. A method to simulate the human electrophysiological activity is proposed and a simulation system is developed, as a calibration tool for electrophysiological inspectors. The system performance is tested by calibrating the amplitude and the latency of a commercial visual electrophysiological instrument. Several typical simulating signals are tested. The minimum amplitude of the simulating signal can be lower than 1 μ V. Measurement errors and uncertainties are calculated. The traceability of the measurement results to metrological standards is also demonstrated. It is proved by experimental results that the …system can generate simulating signals with different waveforms and variable parameters and it can be used to simulate the human visual electrophysiological activities. With simple modifications to the simulation system, it can also be used to calibrate other electrophysiological inspectors. Show more

Keywords: Electrophysiology, simulation system, low amplitude, calibration, metrological traceability

DOI: 10.3233/THC-171319

Citation: Technology and Health Care, vol. 25, no. S1, pp. 167-175, 2017

Authors: Xie, Feng | Zhou, Honghai | Zhao, Wenju | Huang, Lixin

Article Type: Research Article

Abstract: BACKGROUND: Lumbar disc herniation may result in excruciating pain due to it being one of the most common diseases related to changes of intervertebral disc (IVD). In order to find a better clinical treatment and prevention scheme for relieving the pain caused by spine degeneration, the mechanical behavior analysis of IVD must be studied. OBJECTIVE: A finite element method (FEM) is used in this study to analyze the mechanical behaviors of healthy and herniated IVD. METHOD: In order to compare the responses of IVD under different loading conditions for the annulus fibrosus of …IVD, the hyperelastic and elastic constitutive FE models were used in the FEM. RESULTS: The comparison shows that hyperelastic FE models have a much better capability to describe the mechanical behaviors of the IVD than elastic FE models. It can be found from FE simulation that there was a higher stress concentration at the annulus fibrosus of the herniated disc than the healthy disc. CONCLUSIONS: Higher stress concentration resulted in more damage and ease of bringing out lumbar disc herniation. Numerical examples of FE simulation indicate that the FEM with hyperelastic constitutive model has very good capability for analyzing the mechanical behaviors of IVD. Show more

Keywords: Intervertebral disc, finite element model, hyperelastic, lumbar disc herniation, mechanical behavior

DOI: 10.3233/THC-171320

Citation: Technology and Health Care, vol. 25, no. S1, pp. 177-187, 2017

Authors: Xin, Yi | Zhao, Yizhang | Mu, Yuanhui | Li, Qin | Shi, Caicheng

Article Type: Research Article

Abstract: BACKGROUND: Atrial fibrillation (AF) is a common type of arrhythmia disease, which has a high morbidity and can lead to some serious complications. The ability to detect and in turn prevent AF is extremely significant to the patient and clinician. OBJECTIVE: Using ECG to detect AF and develop a robust and effective algorithm is the primary objective of this study. METHODS: Some studies show that after AF occurs, the regulatory mechanism of vagus nerve and sympathetic nerve will change. Each R-R interval will be absolutely unequal. After studying the physiological mechanism of AF, …we will calculate the Rényi entropy of the wavelet coefficients of heart rate variability (HRV) in order to measure the complexity of PAF signals, as well as extract the multi-scale features of paroxysmal atrial fibrillation (PAF). RESULTS: The data used in this study is obtained from MIT-BIH PAF Prediction Challenge Database and the correct rate in classifying PAF patients from normal persons is 92.48%. CONCLUSIONS: The results of this experiment proved that AF could be detected by using this method and, in turn, provide opinions for clinical diagnosis. Show more

Keywords: Atrial fibrillation, heart rate variability, wavelet, entropy

DOI: 10.3233/THC-171321

Citation: Technology and Health Care, vol. 25, no. S1, pp. 189-196, 2017

Authors: Li, Qin | Zhang, Yiyan | Kang, Hongyu | Xin, Yi | Shi, Caicheng

Article Type: Research Article

Abstract: BACKGROUND: Stroke is a frequently-occurring disease and is a severe threat to human health. OBJECTIVE: We aimed to explore the associations between stroke risk factors. METHODS: Subjects who were aged 40 or above were requested to do surveys with a unified questionnaire as well as laboratory examinations. The Apriori algorithm was applied to find out the meaningful association rules. Selected association rules were divided into 8 groups by the number of former items. The rules with higher confidence degree in every group were viewed as the meaningful rules. RESULTS: The …training set used in association analysis consists of a total of 985,325 samples, with 15,835 stroke patients (1.65%) and 941,490 without stroke (98.35%). Based on the threshold we set for the Apriori algorithm, eight meaningful association rules were obtained between stroke and its high risk factors. While between high risk factors, there are 25 meaningful association rules. CONCLUSIONS: Based on the Apriori algorithm, meaningful association rules between the high risk factors of stroke were found, proving a feasible way to reduce the risk of stroke with early intervention. Show more

Keywords: Apriori algorithm, association rules, stroke, risk factors

DOI: 10.3233/THC-171322

Citation: Technology and Health Care, vol. 25, no. S1, pp. 197-205, 2017

Authors: Cai, Haoliuyang | Hao, Zhixiu | Xiao, Liying | Wan, Chao | Tong, Lingying

Article Type: Research Article

Abstract: BACKGROUND: Knee osteoarthritis (OA) is suggested to be induced by multi-factors, and mechanical environment is regarded as a risky factor. OBJECTIVE: To investigate the effect of isolated mechanical factor on cartilage. METHODS: An active wear test system was designed to perform parameters-controlled in vitro wear tests on rat knee joints with specific load magnitude, flexion-extension angle, and movement frequency. Six hind limbs of 9-month-old male Sprague-Dawley rats, with an additional spring on the medial side, were worn by using the custom-designed apparatus. Researchers observed both the menisci and tibial cartilages of these …hind limbs using multiphoton laser scanning microscopy to analyze the change of the collagen microstructure caused by wear. RESULTS: Collagen microstructure of both the medial and lateral meniscus became disordered under cyclic load. Some tissues on the surface of the medial tibial cartilage were removed and the middle layer of the medial compartment displayed cracks. On the contrary, the lateral tibial cartilage was intact. CONCLUSIONS: The results implied that cyclic load caused menisci microstructure disarrangement prior to tibial cartilage damage and the collagen structure of mid-layer tibial cartilage failed before that of the superficial layer under the kinematics adopted in the study. Show more

Keywords: Cartilage, wear test, collagen microstructure, multiphoton microscopy

DOI: 10.3233/THC-171323

Citation: Technology and Health Care, vol. 25, no. S1, pp. 207-217, 2017

Authors: Xiao, Jinzhuang | Zhang, Yunchao | Zhao, Shuai | Wang, Hongrui

Article Type: Research Article

Abstract: BACKGROUND: The 3D motion space of the human ankle is an important area of study in medicine. The 3D motion space can provide significant information for establishing more reasonable rehabilitation procedures and standards of ankle injury care. OBJECTIVE: This study aims to measure the 3D motion space of the human ankle and to use mathematical methods to quantify it. METHODS: A motion capturing system was used to simultaneously capture the 3D coordinates of points marked on the foot, and convert these coordinate values into rotation angles through trigonometric functions and vectors. The mathematical …expression of the ankle’s motion space was obtained by screening, arranging, and fitting the converted data. RESULTS: The mathematical expression of the 3D motion space of the participants was obtained. We statistically analyzed the data and learned that, in terms of 3D motion space, the right foot is more flexible than the left foot and the female foot is more flexible than the male foot. CONCLUSIONS: The adduction and abduction rotation ranges are affected by the plantar flexion or dorsal flexure rotation angles. This relationship can be expressed mathematically, which is significant in the study of the ankle joint. Show more

Keywords: Ankle, 3D motion space, rotation angles, rehabilitation, motion capturing system

DOI: 10.3233/THC-171324

Citation: Technology and Health Care, vol. 25, no. S1, pp. 219-230, 2017

Authors: Zhang, Jinao | Zhong, Yongmin | Smith, Julian | Gu, Chengfan

Article Type: Research Article

Abstract: BACKGROUND: Realistic and real-time modeling and simulation of soft tissue deformation is a fundamental research issue in the field of surgical simulation. OBJECTIVE: In this paper, a novel cellular neural network approach is presented for modeling and simulation of soft tissue deformation by combining neural dynamics of cellular neural network with ChainMail mechanism. METHOD: The proposed method formulates the problem of elastic deformation into cellular neural network activities to avoid the complex computation of elasticity. The local position adjustments of ChainMail are incorporated into the cellular neural network as the local connectivity of …cells, through which the dynamic behaviors of soft tissue deformation are transformed into the neural dynamics of cellular neural network. RESULTS: Experiments demonstrate that the proposed neural network approach is capable of modeling the soft tissues’ nonlinear deformation and typical mechanical behaviors. CONCLUSIONS: The proposed method not only improves ChainMail’s linear deformation with the nonlinear characteristics of neural dynamics but also enables the cellular neural network to follow the principle of continuum mechanics to simulate soft tissue deformation. Show more

Keywords: Surgical simulation, soft tissue deformation, cellular neural network, ChainMail method, real-time performance

DOI: 10.3233/THC-171325

Citation: Technology and Health Care, vol. 25, no. S1, pp. 231-239, 2017

Authors: Yu, Haiyang | Fan, Xingyu | Song, Aiqi

Article Type: Research Article

Abstract: A conclusion has not yet been reached on how exactly the human visual system detects curvature. This paper demonstrates how orientation-selective simple cells can be used to construct curvature-detecting neural units. Through fixed arrangements, multiple plurality cells were constructed to simulate curvature cells with a proportional output to their curvature. In addition, this paper offers a solution to the problem of narrow detection range under fixed resolution by selecting an output value under multiple resolution. Curvature cells can be treated as concrete models of an end-stopped mechanism, and they can be used to further understand “curvature-selective” characteristics and to explain …basic psychophysical findings and perceptual phenomena in current studies. Show more

Keywords: Computer vision, pattern recognition, object detection, image edge detection, spatial resolution

DOI: 10.3233/THC-171326

Citation: Technology and Health Care, vol. 25, no. S1, pp. 241-249, 2017

Authors: Yang, Jinzhu | Deng, Meili | Cao, Peng | Tan, Wenjun | Sun, Qi | Lu, Lin | Zhao, Dazhe

Article Type: Research Article

Abstract: BACKGROUND: Differential demon is a fast and efficient registration algorithm. It drives the floating image to deform using the force based on the gradient between the reference and floating image. But it will cause abnormal deformation when the driving force approaches zero,which limits its practical applications. OBJECTIVE: This paper proposed an improved differential demon algorithm, which aimed to enhance the registration performance of the existing demon algorithm. METHODS: Firstly, we review the original differential demon algorithm. Then, we propose an improved differential demon algorithm and the process of mathematical deduction. Finally, we use …experiment to prove that the improved differential demon algorithm is effective and it can improve the accuracy of registration. RESULTS: We tested our method on data sets provided by Xuanwu Hospital Capital Medical University. The registration performance proved to be better than the original demon algorithm in terms of mutual information, normalized correlation coefficient, mean square error and iteration number. CONCLUSIONS: Experiment results demonstrate the superiority of method proposed in this paper to the original demon algorithm. Show more

Keywords: Image registration, differential, correlation coefficient, gradient, mean square error

DOI: 10.3233/THC-171328

Citation: Technology and Health Care, vol. 25, no. S1, pp. 251-257, 2017