Technology and Health Care - Volume 28, issue S1

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