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ISSN 0928-7329 (P)
ISSN
1878-7401 (E)
Impact Factor 2024: 1.4
Technology and Health Care is intended to serve as a forum for the presentation of original articles and technical notes, observing rigorous scientific standards. Furthermore, upon invitation, reviews, tutorials, discussion papers and minisymposia are featured.
The following types of contributions and areas are considered:
1. Original articles:
Technology development in medicine: New concepts, procedures and devices associated with the use of technology in medical research and clinical practice are presented to a readership with a widespread background in engineering and/or medicine.
Significance of medical technology and informatics for healthcare: The appropriateness, efficacy and usefulness deriving from the application of engineering methods, devices and informatics in medicine and with respect to public health are discussed.
2. Technical notes:
Short communications on novel technical developments with relevance for clinical medicine.
3. Reviews and tutorials (upon invitation only):
Tutorial and educational articles for persons with a primarily medical background on principles of engineering with particular significance for biomedical applications and vice versa are presented.
4. Minisymposia (upon invitation only):
Under the leadership of a Special Editor, controversial issues relating to healthcare are highlighted and discussed by various authors.
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.
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Keywords: Transcranial direct current stimulation (tDCS), interchangeable electrodes
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.
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Keywords: Internal carotid artery (ICA), basilar artery (BA), distance and angle, age and gender
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.
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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.
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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.
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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.
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Keywords: Air Quality Index, pollutant concentration, children, respiratory tract infection, outpatient emergency treatment visits, medical expenses, medical insurance
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.
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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.
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Keywords: Nerve discharge, ion channel, noise, periodic bifurcation process, Chay model
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.
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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.
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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.
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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.
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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.
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Keywords: In vivo measurement, magneto-acoustic source, electrical stimulation, current distribution, lock-in amplifier
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.
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Keywords: Patient referral problem, simulation optimization, bat algorithm
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.
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Keywords: Intended motion direction, rail-based rehabilitative training system, gait rehabilitation
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.
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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.
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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.
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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.
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Keywords: Processing in memory, memory centric computing, near data processing, medical image processing
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.
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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.
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