Enhancement of dielectric performance of encapsulation in barium titanate oxide using size-controlled reduced graphene oxide.

Ferroelectric barium titanate (BTO) powder particles were encapsulated by three different sizes of reduced graphene oxide (rGO) platelets. The size of the graphene oxide (GO) platelets is controlled by varying the horn type ultrasonic times, i.e. 0, 30, and 60 min, respectively, and they are reduced with hydrazine to obtain rGO-encapsulated BTO (rGO@BTO) film. The rGO@BTO film exhibits an increase in the dielectric characteristics due to the interfacial polarization. These improved characteristics include a dielectric constant of 194 (a large increment of 111%), along with the dielectric loss of 0.053 (a slight increment of 13%) at 1 kHz, compared to the pure BTO dielectric film. The improvement in the dielectric constant of the rGO@BTO is attributed to the encapsulation degree between the rGO platelets and BTO powder particles, which results in the interfacial polarization and micro-capacitor effect in a dielectric film, and also contributes to a low dielectric loss. Therefore, a suitable size of rGO platelets for encapsulation is essential for high-dielectric performance.

Predictive Factors of Deep Vein Thrombosis in Gynecologic Cancer Survivors with Lower Extremity Edema: A Single-Center and Retrospective Study.

This study was conducted to examine predictive factors of deep vein thrombosis (DVT) in gynecologic cancer survivors with lower extremity edema (LEE). In the current single-center, retrospective study, there was a total of 315 eligible patients, including 80 patients with DVT and 235 without DVT. They were therefore divided into two groups: the DVT group (n = 80) and the non-DVT group (n = 235). Then, baseline and clinical characteristics of the patients were compared between the two groups. In our study, distant organ metastasis, advanced stage, lymphadectomy, and amount of intraoperative blood loss had a positive predictive value for the occurrence of DVT in gynecologic cancer survivors presenting LEE. In conclusion, our results indicate that it is necessary to consider the possibility of LEE arising from DVT in gynecologic cancer survivors with advanced-stage cancer, distant organ metastasis, lymphadectomy, and intraoperative blood loss over 1500 mL.

Use of Oral Prednisolone and a 3-Phase Bone Scintigraphy in Patients with Complex Regional Pain Syndrome Type I.

To compare the treatment effects of a high-dose and low-dose oral steroid regimen based on changes in the radioisotope uptake ratio (RUR) observed from three-phase bone scintigraphy (TPBS) in patients with complex regional pain syndrome type I (CRPS I), we retrospectively analyzed data of 34 patients with CRPS I from traumatic brain injury and stroke. Depending on the dose of steroid administered, patients were divided into high-dose (n = 14) and low-dose steroid groups (n = 20). We compared the severity scores, Kozin's classification scores, and RUR observed from TPBS between the two groups. There were significant changes in the severity scores and Kozin's classification between the baseline and 2 weeks from baseline (p < 0.05), however, there were no significant differences in terms of changes in the scores, classification, or the RUR observed from TPBS at 2 weeks from baseline (p > 0.05). There were no treatment-emergent adverse events (TEAEs) such as blood pressure elevation, impaired glycemic control, or gastrointestinal disturbances. Our results indicate that the efficacy profile of a low-dose oral steroid regimen is comparable to that of a high-dose regimen in alleviating symptoms in CRPS I patients. However, additional prospective, large-scale, multi-center studies are warranted to confirm our results.

Feasibility of Ultrasound-Guided Trigger Point Injection in Patients with Myofascial Pain Syndrome.

We compared the feasibility of ultrasound (US)-guided myofascial trigger point (MTrP) injection with that of a blind injection technique following the use of shear wave elastography (SWE) for the measurement of stiffness at the MTrPs in patients with trapezius myofascial pain syndrome (MPS). A total of 41 patients (n = 41) were randomized to either the trial group (n = 21, SWE combined with US-guided injection) or the control group (n = 20, SWE combined with blind injection). At baseline and four weeks, they were evaluated for the manual muscle test (MMT), the range of motion (ROM), pain visual analogue scale (VAS) scores, Shoulder Pain and Disability Index (SPADI) scores and Neck Disability Index (NDI) scores during the abduction, adduction, flexion, extension, external rotation and internal rotation of the shoulder joint. Differences in changes in pain VAS scores, NDI scores and SPADI scores at four weeks from baseline between the two groups reached statistical significance (p = 0.003, 0.012, and 0.018, respectively). US-guided MTrP injection is a more useful modality as compared with a blind injection in patients with MPS.

Effectiveness of limited airway ultrasound education for medical students: a pilot study.

OBJECTIVE: The point-of-care ultrasound of the airway (POCUS-A) is a useful examination method but there are currently no educational programs for medical students regarding it. We designed a POCUS-A training curriculum for medical students to improve three cognitive and psychomotor learning domains: knowledge of POCUS-A, image acquisition, and image interpretation. METHODS: Two hours of training were provided to 52 medical students in their emergency medicine (EM) rotation. Students were evaluated for cognitive and psychomotor skills before and immediately after the training. The validity measures were established with the help of six specialists and eight EM residents. A survey was administered following the curriculum. RESULTS: Cognitive skill significantly improved after the training (38.7±12.4 vs. 91.2±7.7) and there was no significant difference between medical students and EM residents in posttest scores (91.2±7.7 vs. 90.8±4.6). The success rate of overall POCUS-A performance was 95.8%. The students were confident to perform POCUS-A on an actual patient and strongly agreed to incorporate POCUS-A training in their medical school curriculum. CONCLUSION: Cognitive and psychomotor skills of POCUS-A among medical students can be improved via a limited curriculum on EM rotation.

Efficacy and Safety of Intra-articular Injections of Hyaluronic Acid Combined With Polydeoxyribonucleotide in the Treatment of Knee Osteoarthritis.

OBJECTIVE: To assess the clinical efficacy and safety of intra-articular injection of hyaluronic acid (HA) combined with polydeoxyribonucleotide (PDRN) in patients with knee osteoarthritis in comparison with that of HA alone. METHODS: The current single-center, prospective, randomized, double-blind, controlled study was conducted in 36 patients with knee osteoarthritis at our medical institution. All the eligible patients (n=30) were equally assigned to two treatment arms (trial group 'HA+PDRN' and control group 'HA'). For efficacy assessment, the patients were evaluated for the visual analogue scale (VAS) scores, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Knee Society Scores (KSS), all of which served as efficacy outcome measures. We monitored time-dependent changes in efficacy outcome measures at baseline and 1, 3 and 6 months. Subsequently, we compared differences in changes in efficacy outcome measures at 6 months from baseline between the two groups. Moreover, we assessed the safety based on the treatment-emergent adverse events (TEAEs), adverse drug reactions (ADRs) and any other complications serving as safety outcome measures. RESULTS: There were significant differences in changes in the VAS scores, the WOMAC scores in all domains, except 'Stiffness', the total WOMAC scores, and the KSS scores in all the domains at 6 months from baseline between the two groups (p<0.05). In our series, there were no TEAEs, ADRs, and any other complications. CONCLUSION: Intra-articular injections of HA combined with PDRN can also be considered in the treatment of knee osteoarthritis. However, further large-scale and multi-center studies are required to demonstrate the potential of the proposed combination.

Environment and Its Influence on Health and Demographics in South Korea.

As the prevalence of overweight and obesity has been increasing in South Korea, it is critical to better understand possible associations between environmental surroundings and general health status. We characterize key health test readings and basic demographic information from 10,816 South Koreans, obtained from two Ubiquitous Healthcare (U-Healthcare) centers that have distinct surrounding neighborhood characteristics. One is located in a rural area in Busan, the other is located in an urban area in Daegu surrounded by a highly crowded residential and commercial business area. We analyze comprehensive health data sets, including blood pressure, body mass index, pulse rate, and body fat percentage from December 2013 to December 2014 to study differences in overall health test measurements between users of rural and urban U-Healthcare centers. We conduct multiple regression analyses to evaluate differences in general health status between the two centers, adjusting for confounding factors. We report statistical evidence of differences in blood pressure at the two locations. As local residents are major users, the result indicates that the environmental surroundings of the centers can influence the demographics of the users, the type of health tests in demand, and the users' health status. We further envision that U-Healthcare centers will provide public users with an opportunity for enhancing their current health, which could potentially be used to prevent them from developing chronic diseases, while providing surveillance healthcare data.

A Gaussian Model-Based Probabilistic Approach for Pulse Transit Time Estimation.

In this paper, we propose a new probabilistic approach to pulse transit time (PTT) estimation using a Gaussian distribution model. It is motivated basically by the hypothesis that PTTs normalized by RR intervals follow the Gaussian distribution. To verify the hypothesis, we demonstrate the effects of arterial compliance on the normalized PTTs using the Moens-Korteweg equation. Furthermore, we observe a Gaussian distribution of the normalized PTTs on real data. In order to estimate the PTT using the hypothesis, we first assumed that R-waves in the electrocardiogram (ECG) can be correctly identified. The R-waves limit searching ranges to detect pulse peaks in the photoplethysmogram (PPG) and to synchronize the results with cardiac beats--i.e., the peaks of the PPG are extracted within the corresponding RR interval of the ECG as pulse peak candidates. Their probabilities of being the actual pulse peak are then calculated using a Gaussian probability function. The parameters of the Gaussian function are automatically updated when a new pulse peak is identified. This update makes the probability function adaptive to variations of cardiac cycles. Finally, the pulse peak is identified as the candidate with the highest probability. The proposed approach is tested on a database where ECG and PPG waveforms are collected simultaneously during the submaximal bicycle ergometer exercise test. The results are promising, suggesting that the method provides a simple but more accurate PTT estimation in real applications.

U-Healthcare Center Service in Busan City, South Korea: An Empirical Analysis and the Results of 1 Year of Service.

INTRODUCTION: Studies have demonstrated that technological innovation is vital for prosperous economies, and greater technological innovation leads to improved public health indicators. The South Korean government has implemented policies to provide city services using information communication technologies, and ubiquitous healthcare (u-healthcare) wellness is one of these. This article presents the effects of using a u-healthcare center model that proves self-healthcare monitoring can work for the general population. MATERIALS AND METHODS: The u-healthcare center has provided service to the public since April 2013. It is equipped with medical devices that evaluate physiological parameters such as weight, body mass index (BMI), blood pressure (BP), pulse rate (PR), and body fat (BF). This article focuses on the analysis of BMI, BP, PR, and BF parameters. RESULTS: Health test results from 12,766 voluntary patients of the u-healthcare center were analyzed during a 1-year period. The four health parameters from each of the four seasons were analyzed and compared, showing statistically significant seasonal differences. A Duncan's post hoc analysis showed that BMI did not differ between spring and summer, whereas BP differed throughout all seasons. Participation of females was higher compared with males, and men's average BMI was statistically higher than that of the women. Some additional significant findings for all participants were as follows: 48.8% scored normal in BMI, 31.7% scored normal-controlled in BP, 90.7% scored normal in PR, and 24.8% scored normal in BF. A survey showed that 96.4% found the u-healthcare center to be generally helpful, and 95.7% responded that they would recommend it. CONCLUSIONS: Implementation of u-healthcare projects provides a new public service toward evaluating health parameters, providing historical health information access, promoting self-monitoring, and motivating users to be more aware of their own health status.

Enhancing the pulse contour analysis-based arterial stiffness estimation using a novel photoplethysmographic parameter.

In this paper, we propose a novel method for enhancing pulse contour analysis-based arterial stiffness estimation using a simple and low-complexity photoplethysmographic parameter (P2Ocd). The method first eliminates baseline wanders in the digital volume pulse (DVP) by applying a simple morphological filter. The filtered DVP signal is then transformed into a slope sum function signal to simplify the pulse peak detection process by enhancing the upslope of the DVP signal while suppressing its downslope. An adaptive thresholding scheme is applied to detect pulse peaks from the transformed signal. Pulse onsets are then identified as the minimum values between consecutive pulse peaks. The P2Ocd is finally calculated by dividing the time interval between the pulse peak and the pulse onset by the pulse length. In order to assess the agreement of the P2Ocd with an established technique, brachial-ankle pulse wave velocity, we performed Bland-Altman and correlation analyses. Furthermore, we evaluated the P2Ocd-based arterial stiffness estimation in terms of prediction accuracy (% error rate) and repeatability (coefficient of variation). The results show that the proposed measurement agrees well with the established technique and shows a high repeatability; it also has a better predictive accuracy than that of conventional methods. In addition, we show that the proposed parameter further improves the predictive accuracy by combining it with age. The proposed method is therefore highly applicable to small ubiquitous healthcare applications.

How the awareness of u-healthcare service and health conditions affect healthy lifestyle: an empirical analysis based on a u-healthcare service experience.

OBJECTIVE: The objectives of this study are (1) to establish a ubiquitous healthcare (u-healthcare) center for those who wish to use u-healthcare, allowing them to experience the service, and (2) to evaluate the users' awareness and expectations of the service based on their overall assessment. MATERIALS AND METHODS: To establish the u-healthcare center, a kiosk, devices for health checkup, a body-type examination system, and a physical fitness assessment system were installed. Also, a u-healthcare Web site was developed. A survey was conducted on 280 individuals who visited the u-healthcare center and used the service, to determine (1) individual awareness of u-healthcare before using the service and their change of perception after use, (2) factors that affect the use of u-healthcare, and (3) the effects of disease awareness on exercise habits. RESULTS: Only 25.4% of the participants were aware of u-healthcare, and only 36% who saw the u-healthcare center recognized that it was where the u-healthcare service was provided. The group of individuals who were willing to use the u-healthcare showed statistically significant differences in their satisfaction with the overall environment of the center, as well as the specificity of the descriptions, examination results, kindness of the staff, and their responses. Additionally, the group of individuals who were diagnosed with chronic diseases and the group who were not showed statistically significant differences in the number of days on which they exercised lightly or took a walk. CONCLUSIONS: To promote the usage of u-healthcare service, the understanding of the service and the credibility of examination results need to be increased by sharing successful cases. Furthermore, to expand the use of the system that allows a person to regularly check his or her state of health, a lifelong periodical management system linked with another medical welfare program will be needed.

Development and evaluation of a mobile application for personal lifestyle check-up and improvement.

OBJECTIVE: This study aimed (1) to help individuals analyze their own health status by checking their lifestyle, (2) to develop a user-friendly mobile application that offered prescriptions for lifestyle improvement, and (3) to examine whether the developed application had positive effects on users. MATERIALS AND METHODS: In order to develop a lifestyle analysis engine that would operate in an Android(®) (Google, Mountain View, CA)-based mobile application, survey data on health awareness behaviors of 25,124 participants from the 2009 Korean National Health and Nutrition Examination Survey (KNHANES) were analyzed. Additionally, in order for the users to be aware of their lifestyles and explore the effects of the developed mobile application on lifestyle management and improvement, an additional survey of the lifestyle awareness and levels of motivation for lifestyle improvement of 152 users was conducted. RESULTS: The differences between lifestyles before and after using the application were examined. A paired t test was used for questions regarding (1) the level of motivation to improve lifestyles and (2) changes in lifestyle. The lifestyle score was lower after using the program than before using it. Conversely, the level of motivation to improve lifestyle was greater after the program than before it. Both results were statistically significant. CONCLUSIONS: By using the KNHANES, this study developed a mobile application that compared the quantified lifestyles of individuals and enabled individuals to check easily their health statuses, whenever and wherever necessary. The program developed in this study contributed to motivating individuals to be aware of and to improve their lifestyles.

A robust method for pulse peak determination in a digital volume pulse waveform with a wandering baseline.

This paper presents a robust method for pulse peak determination in a digital volume pulse (DVP) waveform with a wandering baseline. A proposed new method uses a modified morphological filter (MMF) to eliminate a wandering baseline signal of the DVP signal with minimum distortion and a slope sum function (SSF) with an adaptive thresholding scheme to detect pulse peaks from the baseline-removed DVP signal. Further in order to cope with over-detected and missed pulse peaks, knowledge based rules are applied as a postprocessor. The algorithm automatically adjusts detection parameters periodically to adapt to varying beat morphologies and fluctuations. Compared with conventional methods (highpass filtering, linear interpolation, cubic spline interpolation, and wavelet adaptive filtering), our method performs better in terms of the signal-to-error ratio, the computational burden (0.125 seconds for one minute of DVP signal analysis with the Intel Core 2 Quad processor @ 2.40 GHz PC), the true detection rate (97.32% with an acceptance level of 4 ms ) as well as the normalized error rate (0.18%). In addition, the proposed method can detect true positions of pulse peaks more accurately and becomes very useful for pulse transit time (PTT) and pulse rate variability (PRV) analyses.

An efficient words typing P300-BCI system using a modified T9 interface and random forest classifier.

The conventional P300-based character spelling BCI system consists of a character presentation paradigm and a classification system. In this paper, we propose modifications to both in order to increase the word typing speed and accuracy. In the paradigm part, we have modified the T9 (Text on Nine keys) interface which is similar to the keypad of mobile phones being used for text messaging. Then we have integrated a custom-built dictionary to give word suggestions to a user while typing. The user can select one out of the given suggestions to complete word typing. Our proposed paradigms significantly reduce the word typing time and make words typing more convenient by typing complete words with only few initial character spellings. In the classification part we have adopted a Random Forest (RF) classifier. The RF improves classification accuracy by combining multiple decision trees. We conducted experiments with five subjects using the proposed BCI system. Our results demonstrate that our system increases typing speed significantly: our proposed system took an average time of 1.83 minutes per word, while typing ten random words, whereas the conventional spelling required 3.35 minutes for the same words under the same conditions, decreasing the typing time by 45.37%.

Effect of Integrated Personalized Health Care System on Middle-Aged and Elderly Women's Health.

OBJECTIVES: Body weight, body mass index (BMI), body fat, and blood pressure are important indicators of a person's health. In this experimental study, we evaluated the effectiveness of an integrated personalized health care system, Health Improvement and Management System (HIMS)-everyday, which instantly provides subjects with biofeedback on their measured body weight, BMI, body fat and blood pressure using a database that stores subjects-customized information. METHODS: The subjects of this study used the system once or twice a week for 8 weeks. We analyzed the changes in their body weight, BMI, body fat, and blood pressure according to their respective usage of the system, and analyzed the changes in their perceived health status and health promoting behavior accordingly. RESULTS: Subjects' body weight, BMI, and blood pressure decreased significantly with respect to their individual usage of the system. Subjects who used the system more frequently showed significant improvement in their body weight, BMI, and body fat. However, subjects' perceived health status and health promoting behavior did not improve significantly. CONCLUSIONS: The study showed that the biofeedback-based personalized health care system was effective in controlling middle-aged and elderly women' body weight, BMI, body fat, and blood pressure.

A knowledge-based approach to arterial stiffness estimation using the digital volume pulse.

We have developed a knowledge based approach for arterial stiffness estimation. The proposed new approach reliably estimates arterial stiffness based on the analysis of age and heart rate normalized reflected wave arrival time. The proposed new approach reduces cost, space, technical expertise, specialized equipment, complexity, and increases the usability compared to recently researched noninvasive arterial stiffness estimators. The proposed method consists of two main stages: pulse feature extraction and linear regression analysis. The new approach extracts the pulse features and establishes a linear prediction equation. On evaluating proposed methodology with pulse wave velocity (PWV) based arterial stiffness estimators, the proposed methodology offered the error rate of 8.36% for men and 9.52% for women, respectively. With such low error rates and increased benefits, the proposed approach could be usefully applied as low cost and effective solution for ubiquitous and home healthcare environments.

Mental health promotion system.

Mental activity promotion system is presented that analyzes, quantifies, trains and prescribes based on analysis of logical, memorizing, concentrative, decisive, in conditions where time and space is involved, possibility of dementia, and on evaluation of lifestyle of subjects. Special consideration has been made to make the system motivational, persuasive, attractive and fun to use. The system has been successfully deployed in Bitgeoul Senior health town, Gwangju, South Korea.

Norm references of fat-free mass index and fat mass index and subtypes of obesity based on the combined FFMI-%BF indices in the Korean adults aged 18-89 yr.

OBJECTIVE: To establish reference values for fat-free mass index (FFMI), fat mass index (FMI), and percent body fat (%BF) in a large Korean adult group of apparently healthy subjects, and to analyze the characteristics of body composition indices among the subtypes of obesity in Korean adults. SUBJECTS AND METHODS: A multicenter, cross-sectional study was conducted on a sample of 1275 community-dwelling healthy Koreans, 504 men and 771 women, aged 18-89 years. Body composition parameters were measured by dual-energy X-ray absorptiometry. FFMI (FFM/height squared) and FMI (FM/height squared) were calculated, and then three subtypes of obesity were divided by FFMI; underlean (or sarcopenic), proportional, and heavy (or muscular) obesity. RESULTS: The reference values (5th-95th percentile) of the reference group (18-59 yr) for the FFMI was 16.3-22.3 kg/m(2) in men and 13.3-17.8 kg/m(2) in women. The %BF increased with age because of the reduction of FFM. Due to lower FFMI in the oldest men, they had the lowest BMI while FMI and BMI of Korean women increased with age like Caucasian women. The %BF among three subtypes of obesity was similar while FMI and BMI were increased as FFMI increased. The prevalence of underlean obesity in men was more than double in women. CONCLUSION: It is essential to analyze FFMI as well as %BF because %BF alone cannot explain the effects of ageing on FFM and the characteristics of subtypes of obesity. This is the first study to present DXA-determined age- and sex-specific percentiles for body composition indices in Korean adults. These reference values may be useful for clinical evaluation of body composition and nutritional status for Korean adults.

Modeling the human body shape in bioimpedance vector measurements.

Human body shape, called somatotype, has described physique of humans in health and sports applications, relating anthropometric measurements to fatness, muscularity and linearity in a structured way. Here we propose a new method based on bioelectric impedance vector analysis (BIVA) of R/H and Xc/H to represent the cross-sectional area and the body cell mass in a given surface area (m(2)) respectively. Data from six gymnasts, ten dancers, and five fashion models, groups whose physiques and BMI ranges were distinct from one another, were measured for somatotype and BIVA. The models had highest values of the R/H and gymnasts the lowest. Xc/H was lower in models than in the dancers and gymnasts (p < 0.05). Phase angle was lowest in the models and highest in gymnasts significantly (p < 0.05). Pattern analysis from BIVA corresponded to the calculated anthropometric somatotype supporting the hypothesis that BIA's resistance (R) and reactance (Xc) are meaningful discriminates of body size and function which relate to physique in a purposive way.

PPG delineator for real-time ubiquitous applications.

This paper presents real-time signal processing algorithm for detection of onsets and peaks in Photoplethysmogram (PPG) waveform. Algorithm relies on the analysis of amplitude, slope and inter-beat intervals. The presented algorithm consists of four stages for characterizing PPG waveform. Preprocessing stage involves transformation of PPG since the original waveform is less impulsive and robust. In second stage, algorithm seeks for valid pulse detection in transformed signal complying with the amplitude threshold and inter-beat interval. On detection of valid pulses, algorithm then searches backward and forward in transformed signal for the detection of peaks and onsets. Further the detection parameters are made adaptive to comply with varying beat morphologies and fluctuations in baseline. All signal processing steps and decision logics are implemented with low computational complexity to make it applicable for compact ubiquitous health monitoring devices. On evaluation with our database, the algorithm achieved sensitivity of 96.89% and positive predictivity of 94.55% within an acceptance level of 12 ms.