Technology and Health Care - Volume 28, issue S1

Authors: Liu, Chengping | Wanyan, Xiaoru | Xiao, Xu | Zhao, Jingquan | Duan, Ya

Article Type: Research Article

Abstract: BACKGROUND: The aircraft cockpit is a highly intensive human-computer interaction system, and its design directly affects flight safety. OBJECTIVE: To optimize the display interface design in complex flight tasks, the present study aimed to propose a dynamic conceptual framework and a timeline task analysis method for the quantization of the dynamic time effect of mental workload and the influencing factors of task types in the mental workload prediction model. METHODS: The multi-factor mental workload prediction model based on attention resource allocation was integrated to establish the dynamic prediction model of mental workload. The …ergonomics simulation experiment was carried out by recording the data on the performance of embedded subtasks, National Aeronautics and Space Administration-Task Load Index (NASA-TLX) subjective evaluation, and eye tracking. RESULTS: The results indicated that the prediction model had a good prediction accuracy and effectiveness under different simulated interfaces and complex tasks, and the real-time monitoring of pilots’ mental workload state was realized. CONCLUSION: In conclusion, the prediction model and the experimental method could be applied to avoid the overload of the pilot throughout the flight phase by optimizing the display interface and adjusting the flight task. Show more

Keywords: Ergonomics, information theory, mental workload, prediction model, timeline analysis

DOI: 10.3233/THC-209021

Citation: Technology and Health Care, vol. 28, no. S1, pp. 207-216, 2020

Authors: Shin, Young-Suk

Article Type: Research Article

Abstract: BACKGROUND: Blood pressure (BP) is currently diagnosed by cuff-based devices, which are inconvenient and provide discontinuous measurements. Photoplethysmography (PPG)-based cuffless techniques have recently been used to accurately estimate both systolic BP (SBP) and diastolic BP (DBP). However, it is difficult to use these SBP and DBP estimations to reflect the personalized traits in the peripheral vascular condition; thus, their accuracy is limited. OBJECTIVE: The purpose of this study is to describe a technique that can be distinguished simply among three BP categories (normotensive, prehypertensive, and hypertensive) and reflect individual traits using PPG only. METHODS: …We measured BP over 120 s using the fingers of 105 subjects. The PPG waveforms varied in size and amplitude over time. Therefore, normalization for uniform features for individual traits was done after the extracted waveforms were divided into multiple windows. The feature is determined by the lowest amplitude in the waveform within each divided window. The features have been applied to distinguish three BP categories using the first-eigenvector (1-EV) and second-eigenvector (2-EV) in linear discriminant analysis. RESULTS: The best decision boundary for each BP category was estimated using 1-EV (- 0.02 to + 0.02) and 2-EV ( > + 0.02) in the hypertensive category, 1-EV (< 0) and 2-EV ( ⩽ + 0.02) in the prehypertensive category, and 1-EV ( ⩾ - 0.02) and 2-EV ( ⩽ + 0.02) in the normotensive category. The overlap range with 1-EV (- 0.02 to 0) and 2-EV ( ⩽ + 0.02) in particular accurately reflected individual traits. CONCLUSION: Discrimination among the three BP categories reflecting individual traits was successfully achieved using PPG. This method could improve limitations of cuff-based techniques. Show more

Keywords: Blood pressure, photoplethysmography, personalized trait, maximum low amplitudes, linear discriminant analysis

DOI: 10.3233/THC-209022

Citation: Technology and Health Care, vol. 28, no. S1, pp. 217-227, 2020

Authors: Han, Kap-Soo | Kim, Gi-Wook | Kang, Seung-Rok | Ko, Myoung-Hwan | Seo, Jeong-Hwan

Article Type: Research Article

Abstract: BACKGROUND: Bracing is one of the oldest non-operative treatments for patients with scoliosis. However, a wide variety of braces is used, and some show no effect, while others show conflicting results. OBJECTIVE: We aimed to evaluate the effectiveness of a new orthotic device for the treatment of adult scoliosis. METHODS: Twenty adult patients who were diagnosed with scoliosis and qualified for the study were selected and all participants were treated for 12 hours/day for 12 weeks using a new orthotic device. Various efficacy assessments (Cobb’s angle, spine length, pelvic angle, shoulder angle, thoracic …angle, lumbar angle, pelvic sacral angle) were performed before and after the 12-week treatment. The values at each time point were compared. RESULTS: There were significant treatment effects in a time-dependent manner on every efficacy assessment (p < 0.05) after 12 weeks of bracing. CONCLUSION: In this clinical study, it was demonstrated that a new brace that is more comfortable for the wearer reduced scoliosis and may be a useful option for non-operative treatment of scoliosis. Show more

Keywords: Scoliosis, orthotic device, non-operative treatment, spine, rehabilitation

DOI: 10.3233/THC-209023

Citation: Technology and Health Care, vol. 28, no. S1, pp. 229-236, 2020

Authors: Peng, Yangzhi | Su, Yue | Jiang, Yong

Article Type: Research Article

Abstract: OBJECTIVE: To study the molecular mechanism of warming and tonifying kidney-yang recipe (WTKYR) in the treatment of depression. METHODS: SD rats were divided into a control group, model group, WTKYR group, and fluoxetine group. Each group consisted of 21 rats. The chronic unpredictable mild stress model was used. Body weighing and SPT were performed regularly. After treatment, histopathology of the brain tissue was performed, and concentrations of 5-HT (5-hydroxytryptamine), NE (norepinephrine), and DA (dopamine) in the hippocampus were determined. RESULTS: The WTKYR group showed higher body weight and sucrose consumption than the control …groups. Moreover, the concentrations of 5-HT, NE, and DA in the hippocampus were significantly different in the WTKYR group in comparison to those in the other groups. The hippocampus histomorphology of the WTKYR group exhibited less dematous pyramidal cells and mild inflammatory cell infiltration. CONCLUSION: The treatment effect of WTKYR in depression may be based on improvement in the content of 5-HT, NE, and DA in the hippocampus, extenuating edema of the cortical surface and pyramidal cells and decreasing the infiltration of inflammatory cells into hippocampus tissue. Show more

Keywords: WTKYR, depression, kidney-yang, brain histopathology, monoamine neurotransmitters

DOI: 10.3233/THC-209024

Citation: Technology and Health Care, vol. 28, no. S1, pp. 237-244, 2020

Authors: Hu, Bing | Wang, Dingjiang | Shi, Qianqian

Article Type: Research Article

Abstract: BACKGROUND: Absence epilepsy (AE) is a systemic disease of the brain, which mainly occurs during childhood and adolescence. The control mechanism is still unclear, and few theoretical studies have been conducted to investigate this. OBJECTIVE: In this paper, we employed external direct voltage stimulation in the subthalamic nucleus to explore mechanisms that inhibit absence seizures. METHODS: All simulation results are obtained by the four-order Runge-Kutta method in the MATLAB environment. The inhibition mechanism can be inferred from the results. RESULTS: We found that the seizures may be inhibited by tuning …the strength of the voltage to suitable ranges. This regulation may be achieved through the competition between the inhibitory projections from the basal ganglia to the thalamus. CONCLUSION: Because the mechanism underlying the treatment of epilepsy with a uniform direct current electric field is unclear, we hope that these results can inspire further experimental studies. Show more

Keywords: Absence seizure, subthalamic nucleus, voltage, control, network

DOI: 10.3233/THC-209025

Citation: Technology and Health Care, vol. 28, no. S1, pp. 245-251, 2020

Authors: Kim, Kyong | Kim, Tae-Won | Kim, Seong Hyun

Article Type: Research Article

Abstract: BACKGROUND: Analysis of the change pattern of a user’s physiological signals collected over a long time and user health information prediction technology based on personal history data can provide the user with accurate health information. OBJECTIVE: In this study, we analyzed the change pattern of health information that was altered by performing personal training (PT) at the beginning of the study and subsequently quitting exercise and only performing activities of daily living (ADL). METHODS: The subject performed PT for 75 days, and then consistently performed relatively simple ADL, such as standing, sitting, and …walking, for 325 days that followed. After 400 days, the health information was analyzed through the change patterns of various physiological signals. Personal exercise information and heart rate data were collected through a smart watch (Apple watch Nike+ , Apple Inc.) and the obesity parameters (i.e. information on the weight, body fat fate, and body muscle rate) were measured using a smart scale (PICOOC S1 Pro, EasySolar). RESULTS: We found that the weight and body fat rate linearly decreased and the body muscle rate increased for the first 75 days when hard training was performed whereas they repeatedly increased or decreased when only ADL were performed. As the daily exercise distance increased, weight and body fat rate tended to decrease while body muscle rate tended to increase. There was no significant change in the weight, body fat rate, and body muscle rate while daily activities were performed, but continuous exercise is expected to improve cardiac function by increasing the cardiac output of the heart. CONCLUSION: We expected that the simple physiological data measured with smart watches and smart scales can be used for the health management of the elderly living in rural areas in the future. Show more

Keywords: Health management, personal health pattern, long-term physiological signals, heart rate, daily activities

DOI: 10.3233/THC-209026

Citation: Technology and Health Care, vol. 28, no. S1, pp. 253-262, 2020

Authors: Shao, Zeguo | Xiang, Yuhong | Yan, Mina | Chen, Wei

Article Type: Research Article

Abstract: BACKGROUND: With the gradual aging of China’s population development, the number of disabled elderly has increased significantly. OBJECTIVE: In order to better solve the problem of life care for these elderly people, it is necessary to conduct in-depth and detailed research on the specific conditions of disabled elderly people, in order to differentiate different conditions for care and set appropriate insurance provisions. METHODS: Based on the detailed analysis of the basic behavioral ability of the elderly, and referring to the International Disability standards, this paper refines the three basic living ability indicators of …physiological behavior, cognitive behavior and interpersonal behavior, and integrates the cultural elements of assimilation, continuity, fusion and cohesion with Chinese characteristics. A more systematic and perfect five-level disability scale which conforms to the national conditions of China is designed. RESULTS: The disability of the elderly in Shanghai was investigated with the newly constructed scale, and a detailed analysis and five-level division were made. CONCLUSION: Experiments show that the results of this study can more effectively establish the disability level of the elderly in China. Show more

Keywords: Behavioral ability, disabled elderly, disability level

DOI: 10.3233/THC-209027

Citation: Technology and Health Care, vol. 28, no. S1, pp. 263-271, 2020

Authors: Chou, Ryan | Chi, Hung-Yi | Lin, Yi-Hung | Ying, Liu-Kuo | Chao, Yu-Ju | Lin, Cheng-Hsun

Article Type: Research Article

Abstract: BACKGROUND: Metal artifact reduction (MAR) techniques can improve metal artifacts of computed tomography (CT) images. OBJECTIVE: This work focused on conducting a quantitative analysis to compare the effectiveness of four commercial MAR techniques on three types of metal implants (hip implant, spinal implant, and dental filling) with a self-made acrylic phantom. METHODS: A cylindrical phantom was made from acrylic with a groove in the middle, and then three types of metal implants were placed in the groove. The phantom was scanned by four CT scanners and four commercialized MAR techniques were used to …analyze the images. The techniques used were single-energy metal artifact reduction (SEMAR, Canon), smart metal artifact reduction software (Smart-MAR, GE), iterative metal artifact reduction (IMAR, Siemens), and metal artifact reduction for orthopedic implants (OMAR, Philips). Quantitative analysis methods included objective and subjective analysis. RESULTS: The expected value of SEMAR, Smart-MAR, IMAR, and OMAR were 36.6, 37.8, 5.0, and 2.3, respectively. SEMAR and Smart-MAR achieved optimal results. CONCLUSION: This study successfully evaluated the effects of four commercial MAR techniques on three types of metal implants in a phantom. All MAR techniques effectively reduced metal artifacts, but the effect was not significant with dental fillings due to high-density material. Show more

Keywords: Computed tomography, metal artifact reduction, quantitative analysis

DOI: 10.3233/THC-209028

Citation: Technology and Health Care, vol. 28, no. S1, pp. 273-287, 2020

Authors: Wang, Feng | Zhang, Haisheng | Bao, Junlin | Li, Huaiqiang | Peng, Weihao | Xu, Jia | Yang, Jun | Zhuang, Wei | Ning, Xu | Xu, Lin | Qiao, Liang | Qin, Mingxin | Chen, Mingsheng

Article Type: Research Article

Abstract: BACKGROUND: Hemorrhagic stroke and ischemic stroke have similar symptoms at the onset of the disease, but their clinical treatment is completely different. The early, effective identification of stroke types can effectively improve the cure rate. OBJECTIVE: In this study, an early, noncontact identification of the stroke type, i.e., hemorrhagic or ischemic, based on a microwave measurement technique was investigated. METHODS: This study was based on animal models of cerebral hemorrhage and cerebral ischemia and the design of a microwave scattering parameter measurement system. RESULTS: The accuracy of the cerebral hemorrhage …model with a blood loss interval of 2 ml reached 93.75%. While the accuracy of the cerebral ischemia model with an ischemic interval of 42 minutes reached 91.7%. CONCLUSION: The experimental results show that the system for identifying cerebral stroke based on microwaves can distinguish between cerebral hemorrhage and cerebral ischemia models and effectively distinguish between different degrees of cerebral hemorrhage or different durations of cerebral ischemia. This experimental system is inexpensive, portable, noninvasive, simple, and rapid and thus has good potential as a method for identifying the stroke type prior to hospitalization. Show more

Keywords: Stroke type diagnosis, cerebral hemorrhage, cerebral ischemia, microwave detection, noncontact diagnosis

DOI: 10.3233/THC-209029

Citation: Technology and Health Care, vol. 28, no. S1, pp. 289-301, 2020

Authors: Zhang, Jianfeng | Lu, Zhiying | Li, Min

Article Type: Research Article

Abstract: BACKGROUND: The chaotic system with low dimensions has a low security compared to the high-dimensional chaotic system. Furthermore, major pixel-level permutations merely transform the pixel position and cannot change the intensity distribution of the original image. Bit-level permutation could change the intensity distribution, as it devotes more time to conduct bit-level computation. OBJECTIVE: In this study, we present a more efficient image encryption approach based on hyper-chaos and a global bit cycle shift (HC-GBCS). METHODS: According to the input image we adopted the SHA-256 secure hash algorithm to obtain the initial key, which …served as the premier parameter of the chaotic system. Then we employed a 4D hyper-chaotic system for generating the chaotic series, on which we utilized global bit permutation to enhance the security of the encryption system. Finally, the diffusion process was conducted by using the generated chaotic series extended with a logistic map. RESULTS: Experimental results and analysis reveal that the presented approach encrypts plain images effectively and achieves high security and stability. CONCLUSION: The proposed method can deal with the problems inherently existing in encryption methods utilizing low-dimensional chaotic map. Furthermore, global bit permutation can transform the pixel distribution of plain images and enhance the cryptosystem security. Show more

Keywords: Hyper-chaos, global bit cycle shift, SHA-256, encryption

DOI: 10.3233/THC-209030

Citation: Technology and Health Care, vol. 28, no. S1, pp. 303-309, 2020

Authors: Lee, Gihyoun | Park, Ji-Su | Cho, Hong-Sig | Lee, Bong-Choon | Jung, Young-Jin

Article Type: Research Article

Abstract: BACKGROUND: Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that can help modulate cortical excitability by transmitting direct current (DC) between a pair of scalp electrodes. To date, most studies on tDCS have been relatively short-lived, and the DC stimulations only lasted a few minutes. Conventional tDCS devices usually have some problems such as needing a lot of patches and lead lines. OBJECTIVE: Since conventional tDCS devices are unsuitable for use in long-term stimulations, we developed a new tDCS which can easily be used by unskilled persons. METHODS: We developed …a new tDCS device that does not have lead lines for tDCS electrodes and has a simple structure. RESULT: This device can achieve stimulation with polarity interchangeable DC without physically swapping the anode and cathode. The performance of the proposed device was verified through an experiment. CONCLUSION: The developed tDCS device can contribute to long-term research as it uses neuroelectric stimulation. Show more

Keywords: Transcranial direct current stimulation (tDCS), interchangeable electrodes

DOI: 10.3233/THC-209031

Citation: Technology and Health Care, vol. 28, no. S1, pp. 311-319, 2020

Authors: Choi, Mi-Hyun | Kim, Hyung-Sik | Lee, Beob-Yi | Chung, Soon-Cheol

Article Type: Research Article

Abstract: BACKGROUND: Variations or malformation of the internal carotid artery (ICA) and basilar artery (BA) can be risk factors during simple surgery. So medically the focus has been on information about the positional relationship between the blood vessels based on the distance and angle between the ICA and BA. OBJECTIVE: This study measured the distance and angle between the ICA and BA in 188 healthy Korean male and female subjects in their 20s and 40s and analyzed the differences in terms of age and gender. METHODS: Magnetic resonance images were obtained; the distance between …the right ICA and BA was defined as R1 [cm], the distance between the left ICA and BA was defined as L2 [cm], and the distance between the right ICA and left ICA was defined as M3 [cm]. The angles between the right and left ICA and BA were defined as AR1 [degree] and AR2 [degree], respectively. RESULTS: With increasing age, R1 and M3 became shorter in both men and women, and L2 became shorter only in women. CONCLUSION: The results of this study provide data on the average distance and angle between the ICA and BA of healthy Korean men and women in their 20s and 40s, which may later be used to support the diagnosis of relevant brain diseases and simple routine surgical procedures. Show more

Keywords: Internal carotid artery (ICA), basilar artery (BA), distance and angle, age and gender

DOI: 10.3233/THC-209032

Citation: Technology and Health Care, vol. 28, no. S1, pp. 321-326, 2020

Authors: Yi, Jeong-Han | Kim, Ki-Han | Ahn, Jin-Su | Kim, Hyung-Sik

Article Type: Research Article

Abstract: BACKGROUND: The defibrillator is a device that instantaneously discharges the high energy stored in the capacitor to the human body to help revitalize the heart. The circuit for charging the capacitor uses the same power source as the biosignal measurement unit. Therefore, variation in main power supply voltage, ground noise, and electromagnetic interference from the charging circuit can induce distortion into the biosignal at the initial stage of charging. OBJECTIVE: In this study, a simple method is proposed for removing the initial irregularity of an electrocardiogram due to the transient state of a power supply. …METHODS: To evaluate the method, a 1-channel electrocardiogram measurement unit and peripheral units were separated from the main control module using galvanic isolation. An isolated push-pull converter was designed to power the secondary side. The method was tested under steady-state and transient conditions. RESULTS: The obtained results proved that biosignal distortion can be significantly reduced. CONCLUSION: This method could be another simple implementation approach for solving signal distortions due to the transient status of power supplies used in medical devices. Show more

Keywords: Defibrillator, electrocardiogram, irregularity, transient state, galvanic isolation

DOI: 10.3233/THC-209033

Citation: Technology and Health Care, vol. 28, no. S1, pp. 327-334, 2020

Authors: Kim, Hyung-Sik | Mun, Kyung-Ryoul | Choi, Mi-Hyun | Chung, Soon-Cheol

Article Type: Research Article

Abstract: BACKGROUND: A system that comprehensively analyzes a complex perceptual-motor behavior such as driving, by measuring changes in the central and autonomic nervous systems integrated with measurement of changes in vehicle operation, is lacking. OBJECTIVE: We aimed to develop a functional magnetic resonance imaging (fMRI)-compatible driving simulator to enable simultaneous measurement of physiological, kinematic, and brain activations. METHODS: The system mainly comprises a driving simulator and physiological/kinematic measurement. The driving simulator comprises a steering wheel, an accelerator, a brake pedal, and a virtual-reality optical system. The physiological system comprises a skin-conductance-level and a photoplethysmographic …meter. The kinematic system comprises a 3-axis accelerometer and a 2-axis gyroscope attached to the accelerator foot. To evaluate the influence of the MR system on the MMSD, physiological and kinematic signals were measured. RESULTS: The system did not blur or deform the MR image. Moreover, the main magnetic field, the gradient magnetic field, and the RF pulse of the MR system did not introduce noise into the physiological or kinematic signals. CONCLUSION: This system can enable a comprehensive evaluation of cognitively complex behaviors such as driving, by quantitatively measuring and analyzing concurrent brain activity, autonomic nervous system activity, and human movement during simulated driving. Show more

Keywords: fMRI-compatibility, driving simulator, physiological signal, kinematic signal, multi-biosignal measurement system

DOI: 10.3233/THC-209034

Citation: Technology and Health Care, vol. 28, no. S1, pp. 335-345, 2020

Authors: Chen, Jinliang | Lv, Xuedong | He, Haiyan | Qi, Feng | Chen, Jianrong

Article Type: Research Article

Abstract: OBJECTIVE: We aimed to observe and investigate the clinical significance of vascular endothelium growth factor (VEGF) levels in exhaled breath condensate (EBC) from patients with acute respiratory distress syndrome (ARDS). METHODS: An improved EcoScreen condenser was used to collect EBC from 31 ARDS patients on mechanical ventilation and from 22 healthy subjects. Serum and EBC VEGF levels were analyzed with ELISA. VEGF levels in the EBC of patients with different grades of lung injuries were analyzed. The correlation between VEGF levels and clinical indicators was analyzed. RESULTS: Serum and EBC VEGF levels were …linearly and positively correlated with a correlation coefficient of 0.694 (P < 0.01). The VEGF level in the EBC of ARDS patients was significantly lower than that in the control group (P < 0.01). The VEGF level in the EBC of the mild ARDS group was higher than that in the moderate-severe ARDS group (P < 0.01). The VEGF level in the EBC of the survival group was higher than that in the mortality group. The VEGF level in the EBC of ARDS patients was positively correlated with PaO 2 /FiO 2 and PaO 2 and was negatively correlated with lung injury score (LIS) and A-aDO 2 /PaO 2 . CONCLUSION: The changes in VEGF levels in the EBC of ARDS patients can Respiratory Medicine, reflect the severity of lung injury. Therefore, VEGF level in EBC can be used as an auxiliary index for judging the severity and prognosis of ARDS patients. Show more

Keywords: Vascular endothelium growth factor, exhaled breath condensate, acute respiratory distress syndrome, mechanical ventilation, ELISA, PaO2/FiO2, lung injury score

DOI: 10.3233/THC-209035

Citation: Technology and Health Care, vol. 28, no. S1, pp. 347-354, 2020

Authors: Hu, Fan | Jing, Limei | Shi, Rong

Article Type: Research Article

Abstract: BACKGROUND: In recent years, air pollution and the number of children with respiratory tract infections increased. This also increased the burden related to the treatment of disease, so the government and relevant departments need to strengthen their management. OBJECTIVE: The aim of the present study was to quantitatively analyze the relationship between respiratory infection and air quality in children and gain insight into the burden of related diseases. METHODS: Data regarding outpatient and emergency department visits in children of 14 years or younger in 16 public and private medical institutions were collected for …four months. Routine air quality monitoring data in Shanghai from the same period were correlated with these medical data by descriptive statistics, Pearson’s correlation analysis and multivariate linear regression analysis. RESULTS: There was a positive correlation between respiratory tract infections in 73376 children and Air Quality Index (AQI), PM2.5, SO 2 and NO 2 levels. The total medical expense per patient was 80.22 yuan, and the average compensation ratio of medical insurance per patient was 18.95%. The increase in AQI and the concentration of major air pollutants will lead to increased medical treatment for children with respiratory diseases. CONCLUSION: It is suggested that the intensity of air pollution control should be increased, so that the special period of childhood respiratory protection is strengthened. Moreover, child medical insurance coverage should also be moderately increased to safeguard the rights and interests of children’s health. Show more

Keywords: Air Quality Index, pollutant concentration, children, respiratory tract infection, outpatient emergency treatment visits, medical expenses, medical insurance

DOI: 10.3233/THC-209036

Citation: Technology and Health Care, vol. 28, no. S1, pp. 355-360, 2020

Authors: Lu, Haidan | Zhang, Kaili | Liu, Qiaoyun

Article Type: Research Article

Abstract: BACKGROUND: Pitch perception and pitch matching may link to individual reading skills. OBJECTIVE: In this study, we examined pitch perception and pitch matching tasks in children with learning disabilities to determine whether there was any connection between these tests and the reading fluency in these children. METHOD: The study used different types of pitch discrimination tests and reading fluency tests to compare the two groups. RESULTS: Results indicated that the accuracy of pitch discrimination and reading fluency was significantly different in these children with learning disabilities relative to typically developing …children. This study also indicated that they exhibit impaired pitch matching, which linked to their reading skills. CONCLUSION: The results indicate that processing and production of speech may be impacted by individuals’ musical pitch perception and matching ability. The results may also give us a piece of evidence that we need further research on how these deficits in musical pitch perception affect our speech and language production in children and adults. Show more

Keywords: Learning disabilities, pitch perception, pitch matching, reading fluency

DOI: 10.3233/THC-209037

Citation: Technology and Health Care, vol. 28, no. S1, pp. 361-370, 2020

Authors: Jiang, Zhongting | Wang, Dong | Shang, Huijie | Chen, Yuehui

Article Type: Research Article

Abstract: BACKGROUND: The nervous system senses and transmits information through the firing behavior of neurons, and this process is affected by various noises. However, in the previous study of the influence of noise on nerve discharge, the channel of some noise effects is not clear, and the difference from other noises was not examined. OBJECTIVE: To construct ion channel noise which is more biologically significant, and to clarify the basic characteristics of the random firing rhythm of neurons generated by different types of noise acting on ion channels. Method: Based on the dynamics of …the ion channel, we constructed ion channel noise. We simulated the nerve discharge based on the Chay model of potassium ion channel noise, and used the nonlinear time series analysis method to measure the certainty and randomness of nerve discharge. RESULTS: In the Chay model with potassium ion noise, the chaotic rhythm defined by the original model could be effectively unified with the random rhythm simulated by the previous random Chay model into a periodic bifurcation process. CONCLUSION: This method clarified the influence of ion channel noise on nerve discharge, better understood the randomness of nerve discharge and provided a more reasonable explanation for the mechanism of nerve discharge. Show more

Keywords: Nerve discharge, ion channel, noise, periodic bifurcation process, Chay model

DOI: 10.3233/THC-209038

Citation: Technology and Health Care, vol. 28, no. S1, pp. 371-381, 2020

Authors: Choi, Jin-Seung | Seo, Jeong-Woo | Lee, Jin-Soo | Kim, Jung-Gil | Cho, Jun-Hyeong | Tack, Gye-Rae

Article Type: Research Article

Abstract: BACKGROUND: Gait variability and fractal dynamics may be affected by the walking duration. OBJECTIVE: The purpose of this study is to examine the reproducibility of stride time while walking on a self-paced treadmill. METHODS: Fifteen young and healthy subjects walked on the treadmill for 10 minutes. Three to eight minutes duration of the data were used to compare the trial-to-trial and day-to-day reproducibility of the average, variability, and fractal dynamics of stride time. RESULTS: The results show that all variables had high trial-to-trial reproducibility. In the day-to-day results, the average …walking speed and mean stride time showed reproducibility without regard for duration, but the variability and gait fractal dynamics showed differences in reproducibility according to duration. The variability and fractal dynamics showed better reproducibility in less than 5 minutes and over time, respectively. However, both variables generally showed improved reproducibility when average data from two to three rounds were used. CONCLUSION: Based on the results of this study, it is proposed that variability should be examined using data of 5 min or less, and fractal dynamics should be examined using 5 min or more of repeated data when performing walking tests from a gait dynamics perspective. Show more

Keywords: Reproducibility, self-paced treadmill, walking duration, fractal dynamics, variability

DOI: 10.3233/THC-209039

Citation: Technology and Health Care, vol. 28, no. S1, pp. 383-390, 2020

Authors: Yu, Shuchun | Wang, Qi | Ru, Changhai | Pang, Ming

Article Type: Research Article

Abstract: BACKGROUND: Key area location is an important content of medical image processing and an important detail of auxiliary medical diagnosis. OBJECTIVE: In this paper, a prior knowledge fusion method based on Haar-like feature and contour feature is proposed to locate and detect key areas in medical images. METHOD: For the image to be processed, six Haar-like features and five contour features are extracted respectively. The improvement of Haar-like feature extraction template better adapts to the complexity of regional structure of medical images. The design of the contour feature extraction process fully reflects the …consideration of feature invariance. The two features, together with prior knowledge, are fed into their respective decision makers and final fusers as the basis for determining and locating key regions. RESULTS: The experimental results show that the proposed method has excellent performance in locating key regions of medical images on MRI. When the capacity of the database increases from 10 to 200, the accuracy of locating the key areas of the image to be processed still reaches more than 90%. CONCLUSION: The proposed method realizes the accurate location of the key areas of medical images, which is of great significance for the auxiliary medical diagnosis. Show more

Keywords: Haar-like features, contour features, prior knowledge, location

DOI: 10.3233/THC-209040

Citation: Technology and Health Care, vol. 28, no. S1, pp. 391-399, 2020

Authors: Kang, Hyun-Kyu | Kim, Ki-Han | Ahn, Jin-Su | Kim, Hong-Bae | Yi, Jeong-Han | Kim, Hyung-Sik

Article Type: Research Article

Abstract: BACKGROUND: Microscopic image analysis based on image processing is required for quantitative evaluation of decellularization. Existing methods are not widely used because of expensive commercial software, and machine learning-based techniques lack generality for decellularization because many high-resolution image data has to be processed. OBJECTIVE: In this study, we developed an image processing algorithm for quantitative analysis of tissues and cells in a general microscopic image. METHODS: The proposed method extracts the color images obtained by the microscope into reference images consisting of grayscale, red (R), green (G), and blue (B) information and transforms each into a …binary image. The transformed images were extracted by separating the cells and tissues through outlier noise elimination, logical multiplication and labeling. In order to verify the method, decellularization of porcine arotic valve was performed by the electrical method. Slice samples were obtained by time and the proposed method was applied. RESULTS: The experimental results show that the segmentation of cells and tissues, and quantitative analysis of the number of cells and changes in tissue area during the decellularization process was possible. CONCLUSIONS: The proposed method shows that cell and tissue extraction and quantitative numerical analysis were possible in different brightness of microscopic images. Show more

Keywords: Segmentation, microscope image, image process, decellularization

DOI: 10.3233/THC-209041

Citation: Technology and Health Care, vol. 28, no. S1, pp. 401-410, 2020

Authors: Song, Seong-Mi | Heo, Min | Oh, Seung-Yong | Kim, Kyong | Kwon, Tae-Kyu

Article Type: Research Article

Abstract: BACKGROUND: Mobile rehabilitation systems for patients with gait disorder are being developed. Safety functions to prevent patients from falling are considered during product development; however, few studies have been conducted on systems that have been prevalidated for healthy adults prior to application to patients. OBJECTIVE: This study analyzed the characteristics of lower extremity muscles and foot pressure in healthy adults during unbalanced walking with differences in the speed of left and right speed using a two-belt treadmill. METHODS: Twenty subjects performed gait motions with a difference in the weight support conditions (0% and 30%) …and the left and right lower limb speeds (1–3 km/h). Each subject’s muscular activities and foot pressure signals were collected. The gait patterns of the faster side exhibit similar characteristics to the paralyzed leg, and the slower side is similar to the non-paralyzed leg. RESULTS: Weight-supporting healthy subjects showed asymmetric gait patterns, similar to hemiplegic patients, because of the difference in the speed of the left and right side. CONCLUSIONS: The quantitative results can be used to develop a training protocol for two-belt treadmills with differently controlled left and right speeds for gait rehabilitation in hemiplegic patients. Show more

Keywords: Hemiplegic gait, two-belt treadmill, body weight support, EMG, foot pressure

DOI: 10.3233/THC-209042

Citation: Technology and Health Care, vol. 28, no. S1, pp. 411-419, 2020

Authors: Zhang, Shunqi | Ma, Ren | Zhou, Xiaoqing | Yin, Tao | Liu, Zhipeng

Article Type: Research Article

Abstract: BACKGROUND: Stimulating current distribution in the tissue is unknown due to the complex distribution. OBJECTIVE: A preliminary in vivo measurement of the magneto-acoustic (MA) signal of the human finger is performed in this study. The approach for locating the magneto-acoustic source of the stimulating current is studied. METHODS: We use a lock-in amplifier to measure the MA signal under continuous wave electrical stimulation. The phase of the MA signal is used to extract the location of the sonic source. The experimental system is designed to measure the MA signal under electrical stimulation. …RESULTS: Preliminary experiments results show that the amplitude precision is improved to less than 1 μ Pa. The sonic source is located with millimetre precision. CONCLUSIONS: We propose a new MA source-locating method with high measurement and location precision. This method will be significant to the study of the imaging and monitoring of the current distribution of electrical stimulation with high precision. Show more

Keywords: In vivo measurement, magneto-acoustic source, electrical stimulation, current distribution, lock-in amplifier

DOI: 10.3233/THC-209043

Citation: Technology and Health Care, vol. 28, no. S1, pp. 421-432, 2020

Authors: Yao, Huan-Chung | Chen, Pei-Jarn | Kuo, Yu-Ting | Shih, Chun-Chin | Wang, Xuan-Yin | Chen, Ping-Shun

Article Type: Research Article

Abstract: BACKGROUND: A two-hospital patient referral problem intends to calculate an optimal value of referral patients between two hospitals and to evaluate whether or not the current number of referral patients is too low. OBJECTIVE: The goal of this study is to develop a simulation-based optimization algorithm to find the optimal referral between two hospitals with the unfixed daily patient referral policy. METHODS: This study applied system simulation and a bat algorithm (BA) to build a simulation model in accordance with the status of the two hospitals case and to calculate an optimal value of …daily referral patients. RESULTS: Based on the 20 test instances, we verified the stability of this algorithm. The results show that the average magnetic resonance imaging (MRI) patient wait time reduced from 16 days to eight days. The hospital should increase the average total monthly MRI referral patients to 370 under the limitation of the daily referral patients to 25. CONCLUSIONS: This research investigated the two-hospital patient referral problems. We conducted and analyzed a simulation model and improved the case hospital’s conditions, enhancing the quality of its medical care. The findings of this study can extend to other departments or hospitals. Show more

Keywords: Patient referral problem, simulation optimization, bat algorithm

DOI: 10.3233/THC-209044

Citation: Technology and Health Care, vol. 28, no. S1, pp. 433-442, 2020

Authors: Kim, Kyong | Chong, Woo Suk | Yu, Chang Ho

Article Type: Research Article

Abstract: BACKGROUND: Accurate detection of the intended movement direction of a patient plays an important role in the development of a training system for gait rehabilitation and enables to increase the effect of gait rehabilitation training. OBJECTIVE: This study investigated the detection of the intended movement of a user to operate a ceiling rail-based rehabilitative training system with accurate timing. METHODS: To detect the movement direction intention of a user, two potentiometers were used to measure the movement direction in the anterior, posterior, and left and right directions of the user when operating the driving …motor of the rehabilitative training system. A simple test mock-up with two potentiometers was fabricated, and the experiments were conducted to determine the effect of the direction of movement on the measured values of potentiometers. A direction measurement algorithm was developed to control the driving motor of the rail-based gait rehabilitative training system. RESULTS: The intended movement direction of the user could be predicted for eight directions by combining the “positive value, 0, negative value” of each measured value of the two potentiometers. Further, the developed algorithm was effectively used to control the driving function to assist the walking, sitting–standing, and climbing up–down the step activities in daily life. CONCLUSIONS: The movement intention detection function for users developed in this paper can be used to effectively control a rehabilitative training system for patients with hemiplegia to improve gait movement and posture balance, thereby improving their function of activities of daily living. Show more

Keywords: Intended motion direction, rail-based rehabilitative training system, gait rehabilitation

DOI: 10.3233/THC-209045

Citation: Technology and Health Care, vol. 28, no. S1, pp. 443-452, 2020

Authors: Lin, Zhenkun | Zang, Xizhe | Zhang, Xuehe | Liu, Yubin | Heng, Shuai

Article Type: Research Article

Abstract: BACKGROUND: Biped robot locomotion is an active topic of research, and the walking stability is one of the research objectives. OBJECTIVE: This paper discusses the variable stiffness ankle joint and the walking control of a biped robot. METHODS: A design is introduced that achieves the ankle joint variable stiffness by using a pneumatic unit. The actuation system of the biped robot is based on the hybrid use of electric and pneumatic. The locomotion control architecture has been proposed to exploit natural leg dynamics in order to improve the biped robot walking stability. We also …present a dynamic simulation which matches the biped robot and experiments with the real biped robot. RESULTS: The simulation and experiments result that introducing the variable stiffness ankle joint and the controller achieve a significant improvement in foot-ground impact and walking stability of the biped robot. CONCLUSION: The biped robot with variable stiffness ankle joints has a better walking performance under the control method. Show more

Keywords: Biped robot, variable stiffness ankle joint, foot-ground impact, locomotion control

DOI: 10.3233/THC-209046

Citation: Technology and Health Care, vol. 28, no. S1, pp. 453-462, 2020

Authors: Ma, Guangkun | Yang, Jinzhu | Zhao, Hong

Article Type: Research Article

Abstract: BACKGROUND: Coronary artery image segmentation is an important auxiliary method for coronary artery disease diagnosis. OBJECTIVE: The classical region growing algorithms, which only consider the intensity of pixels, are noise-sensitive and require manual interaction. To this end, recent methods simultaneously consider the intensity of pixels and multi-scale analysis with the region growing. Nevertheless, these methods are not fully optimized and they suffer from the drawbacks of over- or under-segmentation in many cases. METHODS: In this paper, we propose a region growing based coronary artery segmentation method. Different from the existing methods, the variable …sector search area is considered in the region growing technique. A growing rule is proposed to segment the vessel, which combines the Hessian vector and the region growing with the variable sector search area. To further improve the quality of segmentation, we propose an optimization of removing some small disconnected regions. RESULTS: Our proposed method can search more branches while segmenting the vessel, even the small ones. It keeps an acceptable performance when dealing with stenosis and large curvature of blood vessels. CONCLUSIONS: Quantitative evaluations are conducted on coronary angiography and the results show that the proposed method achieves a higher DSC ratio and a more reliable sensitivity ratio. Show more

Keywords: Coronary artery, variable sector search area, region growing, coronary angiography

DOI: 10.3233/THC-209047

Citation: Technology and Health Care, vol. 28, no. S1, pp. 463-472, 2020

Authors: Shin, Mi Yeon | Chong, Woo Suk | Kim, Kyong | Yu, Chang Ho

Article Type: Research Article

Abstract: BACKGROUND: With the improvement in the standard of living, there has been increasing interest in facial skin care. In particular, it has been observed that people pay extra attention to eye-skin when they visit skin care parlors for special treatment and care. OBJECTIVE: There is a need for skin care devices that would enable convenient skin care anywhere, including at home and on the move. In this research, we developed a prototype of a glasses-type skin care device with a LED (Light-Emitting Diode) irradiation function and performed injection molding analysis of the skin care device model …for mass production. METHODS: First, the product was designed using a universal design to improve the wearability of the glasses-type skin care device. The first prototype of the skin care device was produced using an integrated LED optical module capable of irradiating at three LED wavelengths to investigate the structural function of the product. The prototype was classified into three mechanisms and injection molding analysis was performed. The fill time, temperature at flow front, injection pressure, clamp force, and deflection values were analyzed according to the appropriate number and location of gates into which the PC + PBT (Polycarbonate + Polybutylene terephthalate) resin was introduced. RESULTS: We found that all the other parts except the temple section of the device were inferior in moldability. CONCLUSION: In further studies, the 3D prototype will be modified to enhance moldability, and injection molding analysis with other materials as well as with PC + PBT resin will be performed. Show more

Keywords: Glasses-type skin care device, LED, injection molding analysis, wearability, universal design

DOI: 10.3233/THC-209048

Citation: Technology and Health Care, vol. 28, no. S1, pp. 473-485, 2020

Authors: Kim, Young-Kyu | Jang, Young-Jong | Kim, Dong-Sun | Wei, Qun

Article Type: Research Article

Abstract: BACKGROUND: Biomedical engineers in particular require fast and powerful data processing systems to process computerized tomography and magnetic resonance imaging scans and other medical imaging technologies. However, current computer data processing technologies are unable to satisfy such requirements. A promising approach to addressing these limitations is processing in memory (PIM). Unfortunately, several issues, such as the compatibility and interconnection of PIM with legacy systems, still remain. OBJECTIVE: This paper proposes a standard memory bus-based PIM interface for medical image processing and a PIM platform. The proposed PIM interface can overcome problems of compatibility with legacy systems. …METHODS: We will adapt an embedded system based on a commercial application processor (AP) to a medical image system to verify the functions and the performance of the proposed PIM interface. Using the PIM platform, we apply the proposed PIM interface and the AP to execute an image processing program, measure the image processing times, and compare the results of the measurements. RESULTS: Experimental results show that while the functions of the proposed PIM interface are normal, the processing time of PIM is more than 81% faster than that of the AP. CONCLUSION: The experimental results prove that the proposed PIM interface is able to solve problems of compatibility with legacy systems. We foresee that not only the medical image processing field but also a number of academic fields and professional sectors will use PIM in their data-intensive applications. Show more

Keywords: Processing in memory, memory centric computing, near data processing, medical image processing

DOI: 10.3233/THC-209049

Citation: Technology and Health Care, vol. 28, no. S1, pp. 487-497, 2020

Authors: Kwon, Do-Young | Kwon, Yu-Ri | Choi, Yoon-Hyeok | Eom, Gwang-Moon | Ko, Junghyuk | Kim, Ji-Won

Article Type: Research Article

Abstract: BACKGROUND: It is important to quantitatively assess tremor for accurate diagnosis and evaluation of the response to interventions in patients with essential tremor (ET). OBJECTIVE: The purpose of this study was to investigate the relationship between quantitative measures of postural tremor and clinical rating scale in patients with ET. METHODS: 18 ET patients performed a postural tremor task that required them to hold their arms outstretched parallel to the floor while wearing a gyro sensor based measurement system. The time domain variables were derived from the sensor signals. Additionally, the frequency domain variables …were derived from the power spectrum of the angular velocity signal. Spearman correlation analysis was employed in the relationship between the variables and clinical score. RESULTS: The RMS angular velocity of roll and yaw directions at the hand joint were strongly correlated with the clinical rating scale (r = 0.7, p < 0.01). Similarly, the peak power of roll and yaw directions at the hand joint were moderately correlated with the clinical rating scale (r = 0.61 and r = 0.67, p < 0.01). In contrast, no significant correlation coefficients were observed in the peak frequency (p > 0.05). CONCLUSION: These results indicate that hand tremor of roll and yaw directions are more associated with assessment of severity of ET compared to other joints. This study suggests that quantitative measurements of postural tremor should be considered as tremor directionality as well as attachment location. Show more

Keywords: Quantification, essential tremor, gyro sensor, postural tremor, directionality, joint

DOI: 10.3233/THC-209050

Citation: Technology and Health Care, vol. 28, no. S1, pp. 499-507, 2020

Authors: Son, Ji Eun | Choi, Hyoseon | Lim, Hyunmi | Ku, Jeonghun

Article Type: Research Article

Abstract: BACKGROUND: This study focused on developing an upper limb rehabilitation program. In this regard, a steady state visual evoked potential (SSVEP) triggered brain computer interface (BCI)-functional electrical stimulation (FES) based action observation game featuring a flickering action video was designed. OBJECTIVE: In particular, the synergetic effect of the game was investigated by combining the action observation paradigm with BCI based FES. METHODS: The BCI-FES system was contrasted under two conditions: with flickering action video and flickering noise video. In this regard, 11 right-handed subjects aged between 22–27 years were recruited. The differences in brain …activation in response to the two conditions were examined. RESULTS: The results indicate that T3 and P3 channels exhibited greater Mu suppression in 8–13 Hz for the action video than the noise video. Furthermore, T4, C4, and P4 channels indicated augmented high beta (21–30 Hz) for the action in contrast to the noise video. Finally, T4 indicated suppressed low beta (14–20 Hz) for the action video in contrast to the noise video. CONCLUSION: The flickering action video based BCI-FES system induced a more synergetic effect on cortical activation than the flickering noise based system. Show more

Keywords: Brain computer interface (BCI), functional electrical stimulation (FES), flickering action video, steady state visual evoked potential (SSVEP), action observation, rehabilitation, upper limb, mirror neuron system (MNS)

DOI: 10.3233/THC-209051

Citation: Technology and Health Care, vol. 28, no. S1, pp. 509-519, 2020