Technology and Health Care - Volume 26, issue S1

Authors: Kwon, Moon-Seok | Kwon, Yu-Ri | Park, Yang-Sun | Kim, Ji-Won

Article Type: Research Article

Abstract: Gait is associated with an important risk factor of falls in the elderly. It is important to find differences of quantitative gait variables between fallers and non-fallers. The aim of this study was to investigate gait patterns in elderly fallers and non-fallers. Thirty-eight fallers and 38 non-fallers of similar age and height participated in this study. Subjects walked across the GaitRite walkway at self-selected comfortable speeds. Spatio-temporal gait variables were measured to characterize gait patterns. Kinetic variables were derived from normalized vertical ground reaction force (GRF). Independent t-tests were performed to compare the fallers with the non-fallers. The fallers walked …more slowly with shorter steps and more variable step times than the non-fallers (p < 0.05). The fallers showed a longer stance phase with increased double-limb support than the non-fallers (p < 0.05). The times to reach maximal weight acceptance and mid-stance of the fallers were significantly longer than those of the non-fallers (p < 0.05). These results suggest that spatio-temporal variables and GRF variables would be useful for distinguishing prospective fallers from non-fallers among the elderly. Show more

Keywords: Gait, fall, ground reaction force, gait variable, elderly

DOI: 10.3233/THC-174736

Citation: Technology and Health Care, vol. 26, no. S1, pp. 427-436, 2018

Authors: Yang, Peng | Ni, Dong | Chen, Siping | Wang, Tianfu | Wu, Donghui | Lei, Baiying

Article Type: Research Article

Abstract: BACKGROUND: Brain functional connectivity network (BFCN) has been widely applied to identify biomarkers for the brain function understanding and brain diseases analysis. OBJECTIVE: Building a biologically meaningful brain network is a crucial work in these applications. For this task, sparse learning has been widely applied for the network construction. If multiple time-point data is added to the brain imaging application, the disease progression pattern in the longitudinal analysis can be better revealed. METHODS: A novel longitudinal analysis for MCI classification is devised based on resting-state functional magnetic resonating imaging (rs-fMRI). Specifically, this paper …proposes a novel multi-task learning method to integrate fused penalty by regularization. In addition, a novel objective function is developed for fused sparse learning via smoothness constraint. RESULTS: The proposed method achieves the best classification performance with an accuracy of 95.74% for baseline and 93.64% for year 1 data. CONCLUSIONS: The experimental results show that our proposed method achieves quite promising classification performance. Show more

Keywords: Mild cognitive impairment, brain functional connectivity network, longitudinal analysis, smooth regularization

DOI: 10.3233/THC-174587

Citation: Technology and Health Care, vol. 26, no. S1, pp. 437-448, 2018

Authors: Xie, Peng | Wang, Mengke | Guo, Yanrong | Wen, Huiying | Chen, Xin | Chen, Siping | Lin, Haoming

Article Type: Research Article

Abstract: During the past two decades, tissue elasticity has been extensively studied and has been used in clinical disease diagnosis. But biological soft tissues are viscoelastic in nature. Therefore, they should be simultaneously characterized in terms of elasticity and viscosity. In addition, the mechanical properties of soft tissues are temperature dependent. However, how the temperature influences the shear wave dispersion and the viscoelasticity of soft tissue are still unclear. The aim of this study is to compare viscoelasticity of fat emulsion phantom with different temperature using acoustic radiation force elasticity imaging method. In our experiment, we produced four proportions of ultrasonic …phantom by adding fat emulsion gelatin. Through adjusting the component of the fat emulsion, we change the viscoelasticity of the ultrasonic phantom. We used verasonics system to gather data and voigt model to fit the elasticity and viscosity value of the ultrasonic phantom we made. The influence of temperature to the ultrasonic phantom also measured in our study. The results show that the addition of fat emulsion to the phantom can increase the viscosity of the phantom, and the shear wave phase velocity decreases gradually at each frequency with the temperature increases, which provides a new material for the production of viscoelastic phantom. Show more

Keywords: Viscoelasticity, fat emulsion phantom, fatty liver, temperature dependent

DOI: 10.3233/THC-174746

Citation: Technology and Health Care, vol. 26, no. S1, pp. 449-458, 2018

Authors: Liu, Xin | Wang, Qisong | Liu, Dan | Wang, Yuan | Zhang, Yan | Bai, Ou | Sun, Jinwei

Article Type: Research Article

Abstract: BACKGROUND: Human emotion classification is traditionally achieved using multi-channel electroencephalogram (EEG) signal, which requires costly equipment and complex classification algorithms. OBJECTIVE: The experiments can be implemented in the laboratory environment equipped with high-performance computers for the online analysis; this will hinder the usability in practical applications. METHODS: Considering that other physiological signals are also associated with emotional changes, this paper proposes to use a wearable, wireless system to acquire a single-channel electroencephalogram signal, respiration, electrocardiogram (ECG) signal, and body postures to explore the relationship between these signals and the human emotions. …RESULTS AND CONCLUSIONS: Compared with traditional emotion classification method, the presented method was able to extract a small number of key features associated with human emotions from multiple physiological signals, where the algorithm complexity was greatly reduced when incorporated with the support vector machine classification. The proposed method can support an embedded on-line analysis and may enhance the usability of emotion classification. Show more

Keywords: Emotion, wearable sensors, support vector machine, EEG, ECG, respiration

DOI: 10.3233/THC-174747

Citation: Technology and Health Care, vol. 26, no. S1, pp. 459-469, 2018

Authors: Zhu, Shidong | Luo, Lin | Yang, Bibo | Ni, Kai | Zhou, Qian | Li, Xinghui | Wang, Xiaohao

Article Type: Research Article

Abstract: BACKGROUND: A novel intra-ventricular assist device (iVAD) was established as a new pulsatile assist device to address various disadvantages, such as bulky configuration and reduced arterial pulsatility, observed in conventional ventricular assist devices. OBJECTIVE: Analyzed the native left ventricular stroke volume (SV) after iVAD support in vitro . METHODS: The SV of iVAD was examined in a home-designed mock circulatory system (MCS) at different heart rates and drive pressures and the SV of a failure ventricle was examined with iVAD at 75, 90, 120 bpm and 120–180 mmHg drive pressure after iVAD support. …Data pertaining to native left ventricular SV before and after iVAD support were compared. RESULTS: The native ventricular SV was improved by iVAD when its drive pressure (DP) was slightly greater than that of the mock system. Conversely, the native ventricular SV was decreased when DP was much greater than that (150 mmHg) of MCS. A high DP had a significant effect on SV. CONCLUSIONS: The proposed device improved the dysfunctional native left ventricular SV when DP of iVAD was slightly greater than that of MCS. However, iVAD reduced the SV when the drive pressure was greater than that of MCS. Show more

Keywords: Left ventricular assist device, mock circulatory system, pulsatile pump, stroke volume

DOI: 10.3233/THC-174752

Citation: Technology and Health Care, vol. 26, no. S1, pp. 471-479, 2018

Authors: Sohn, Jeehoon | Park, Sung-Ha | Kim, Sukwon

Article Type: Research Article

Abstract: BACKGROUND: Dancesport is a popular activity among older adults who look for fun and fitness in Korea. Studies reported positive sociological and psychological effects of dancesport. But, little studies were performed to evaluate the effects of dancesport on balance performances. OBJECTIVE: The objective of the present study was to evaluate the effects of dancesport for 15 weeks on walking balance and standing balance of older adults. METHODS: Older adults regularly participated in the dancesport program 3 times a week for 15 weeks. The program included Rumba, Cha-cha-cha, and Jive. They exercised the prescribed …dancesport at intermediate level for 50–60 mins for each time. A total 22 reflective markers were placed on the anatomical landmarks and 8 cameras were used to measure 3-D positions of participants. Also, center of pressure (COP) data were measured to analyze standing balance using a ground reaction board at 1200 Hz for 30 seconds. One-way analysis of variance (ANOVA) was performed to test the effects of 15 weeks of dancesport on walking balance and standing balance. RESULTS: The results suggested that, after 15 weeks of dancesport participation, older adults’ walking balance (48.3 ± 20.3 cm 2 vs 38.2 ± 18.2 cm 2 ) and standing balance (COP area: 189.4 ± 85.4 mm 2 vs 103.5 ± 55.4mm 2 , COP distance: 84.2 ± 34.4 cm vs 76.5 ± 21.4 cm) were significantly improved. CONCLUSION: Performing dancesport would require moving center of mass rapidly and frequently while maintaining posture. This may result in improving walking balance and standing balance in the present study. The study concluded that dancesport would be an effective exercise method in enhancing postural stability of older adults. Show more

Keywords: Dancesport, stability, balance, walking, falls, elderly

DOI: 10.3233/THC-174760

Citation: Technology and Health Care, vol. 26, no. S1, pp. 481-490, 2018

Authors: Wei, Qun | Kim, Mi-Jung | Lee, Jong-Ha

Article Type: Research Article

Abstract: BACKGROUND: Drinking water has several advantages that have already been established, such as improving blood circulation, reducing acid in the stomach, etc. However, due to people not noticing the amount of water they consume every time they drink, most people drink less water than the recommended daily allowance. OBJECTIVE: In this paper, a capacitive sensor for developing an automatic tumbler to measure water level is proposed. Different than in previous studies, the proposed capacitive sensor was separated into two sets: the main sensor for measuring the water level in the tumbler, and the reference sensor for …measuring the incremental level unit. METHODS: In order to confirm the feasibility of the proposed idea, and to optimize the shape of the sensor, a 3D model of the capacitive sensor with the tumbler was designed and subjected to Finite Element Analysis (FEA) simulation. According to the simulation results, the electrodes were made of copper and assembled in a tumbler manufactured by a 3D printer. The tumbler was filled with water and was subjected to experiments in order to assess the sensor’s performance. RESULTS: The comparison of experimental results to the simulation results shows that the measured capacitance value of the capacitive sensor changed linearly as the water level varied. This proves that the proposed sensor can accurately measure the water level in the tumbler. Additionally, by use of the curve fitting method, a compensation algorithm was found to match the actual level with the measured level. CONCLUSIONS: The experimental results proved that the proposed capacitive sensor is able to measure the actual water level in the tumbler accurately. A digital control part with micro-processor will be designed and fixed on the bottom of the tumbler for developing a smart tumbler. Show more

Keywords: Capacitive sensor, water level, 3D modeling, FEA simulation, compensation algorithm

DOI: 10.3233/THC-174794

Citation: Technology and Health Care, vol. 26, no. S1, pp. 491-500, 2018

Authors: Li, Yan | Dai, Yongliang | Guo, Youmin

Article Type: Research Article

Abstract: BACKGROUND: Smoking for a long period is known to cause several harms to the human body, chiefly associated with serious pulmonary damage. OBJECTIVE: The purpose of this study was to evaluate the difference in the pulmonary damage between current smokers and ex-smokers, through measuring the bronchial parameters and the extent of emphysema, in order to further illustrate the harm of smoking and the need to stop smoking. METHODS: Using the FACT-Digital lung TM software quantitatively analysis of CT images, including the WT, WA%, LD, LV, PD, and %LAA-950 was performed. The percentage of low attenuation …areas less than -950 Hounsfield units (%LAA-950) was defined as the extent of emphysema. The longitudinal data in the two consecutive years of these current smoker group and ex-smoker group were compared by paired t-test. RESULTS: The LV, %LAA-950, WT and WA% of current smokers increased more rapidly each year than that of ex-smokers. The PD and LD of current smokers declined more rapidly each year than that of ex-smokers. CONCLUSIONS: This study shows that pulmonary damage caused by smoking related to the smoking status, can be measured. Smoking cessation has a positive role in alleviating the progress of pulmonary damage. Show more

Keywords: Quantitative CT measurements, smoking, computed tomography, longitudinal study

DOI: 10.3233/THC-174800

Citation: Technology and Health Care, vol. 26, no. S1, pp. 501-507, 2018

Authors: Li, Mi | Xu, Hongpei | Liu, Xingwang | Lu, Shengfu

Article Type: Research Article

Abstract: BACKGROUND: Many studies have been done on the emotion recognition based on multi-channel electroencephalogram (EEG) signals. OBJECTIVE: This paper explores the influence of the emotion recognition accuracy of EEG signals in different frequency bands and different number of channels. METHODS: We classified the emotional states in the valence and arousal dimensions using different combinations of EEG channels. Firstly, DEAP default preprocessed data were normalized. Next, EEG signals were divided into four frequency bands using discrete wavelet transform, and entropy and energy were calculated as features of K-nearest neighbor Classifier. RESULTS: The …classification accuracies of the 10, 14, 18 and 32 EEG channels based on the Gamma frequency band were 89.54%, 92.28%, 93.72% and 95.70% in the valence dimension and 89.81%, 92.24%, 93.69% and 95.69% in the arousal dimension. As the number of channels increases, the classification accuracy of emotional states also increases, the classification accuracy of the gamma frequency band is greater than that of the beta frequency band followed by the alpha and theta frequency bands. CONCLUSIONS: This paper provided better frequency bands and channels reference for emotion recognition based on EEG. Show more

Keywords: Emotion recognition, multi-channel EEG, DWT, Valence, Arousal

DOI: 10.3233/THC-174836

Citation: Technology and Health Care, vol. 26, no. S1, pp. 509-519, 2018

Authors: Ye, Fuli | Zhan, Huimiao | Shi, Guilian

Article Type: Research Article

Abstract: BACKGROUND: The preoperative evaluation of liver functional reserve is very important to determine the excision of liver lobe for the patients with liver cancer. There already exist many effective evaluation methods, but these ones have many disadvantages such as large trauma, complicated process and so on. OBJECTIVE: Therefore, it is essential to develop a fast, accurate and simple detection method of liver functional reserve for the practical application in the clinical engineering field. METHODS: According to the principle of spectrophotometry, this paper proposes a detection method of liver functional reserve based on three-wavelength …from red light to infrared light (IR), in which the artery pulse, the vein pulse and the move of tissue are taken into account. RESULTS: By using photoelectric sensor technology and excreting experiment of indocyanine green, a minimally invasive, fast and simple testing equipment is designed in this paper. CONCLUSIONS: The testing result shows this equipment can greatly reduce the interference from human body and ambient, realize continuous and real-time detection of arterial degree of blood oxygen saturation and liver functional reserve. Show more

Keywords: Liver functional reserve, pulse blood oxygen, three-wavelength, photoelectric conversion

DOI: 10.3233/THC-174843

Citation: Technology and Health Care, vol. 26, no. S1, pp. 521-529, 2018