This letter proposes a soft wearable robot with shape memory alloy (SMA)-based artificial muscle ... more This letter proposes a soft wearable robot with shape memory alloy (SMA)-based artificial muscle to assist with upper limb motion. The SMA-based artificial muscle was designed by embedding a bundle of SMA coil springs into a stretchable coolant vessel, which allows active cooling of the SMA bundles through coolant circulation. By attaching SMA-based artificial muscles to a soft wearable brace, a soft wearable robot was designed to assist elbow flexion and forearm supination/pronation. To support the activities of daily living (ADLs), the proposed robot can produce more than 3 Nm torque in the direction of elbow flexion. In addition, the proposed robot can increase the forearm supination/pronation ROM by an average of 15.7° for impaired users. Finally, to evaluate the effect of the assistance provided by the proposed system, experiments and system usability scale (SUS) assessments were conducted on a group of patients with stroke and spinal cord injuries (SCI). The results indicate that the robot improves not only the range of motion (ROM) but also the torque produced by the users. In addition, from the results of the user experiment, we found certain design issues that require further development for better performance of the robot.
This article proposes a shape memory alloy (SMA)-based artificial muscle that has an active cooli... more This article proposes a shape memory alloy (SMA)-based artificial muscle that has an active cooling system. An SMA coil spring is embedded into a stretchable coolant vessel, which allows active cooling of SMA through coolant circulation. The coolant effect has been investigated by measuring actuation speed. Integrating a thermomechanical model and heat transfer model between coolant and SMA, actuation times have been estimated. Based on these results, actuation performances that use four different coolants have been found out, and the mineral oil cooling case shows both contraction and extension times of less than 1 s to contract to over 35% of its initial length with 1 kg load. A soft wearable robot for assisting wrist motion has been designed by integrating multiple SMA muscles with a glove, wristband, and elbow anchor. Thanks to the advantages of the SMA coil spring actuator, the proposed robot is compliant and weight-balanced structure. The robot shows ranges of motion of 38°, 50°, 34°, and 35°, for flexion, extension, radial deviation, and ulnar deviation, respectively. In addition, the robot shows improved cyclic performance compared to a natural air-cooling system. Finally, its torque assistance and theamount of time needed to wear it have been analyzed with user tests.
Background The Korean Society of Hypertension has published the Korea Hypertension Fact Sheet 202... more Background The Korean Society of Hypertension has published the Korea Hypertension Fact Sheet 2020 to provide an overview of the magnitude and management status of hypertension and their recent trends. Methods The Fact Sheets were based on the analyses of Korean adults aged 20 years or older of the 2007–2018 Korea National Health and Nutrition Examination Survey (KNHANES) and the 2002–2018 National Health Insurance Big Data (NHI-BD). Results Currently, the population average of systolic/diastolic blood pressure was 118/76 mmHg in Korean adults aged 20 years or older showing little change in the recent decade. However, the number of people with hypertension increased steadily, exceeding 12.0 million. Indeed, the number of people diagnosed with hypertension increased from 3.0 million in 2002 to 9.7 million in 2018. During the same period, the number of people using antihypertensive medication increased from 2.5 million to 9.0 million, and the number of people adherent to treatment inc...
Background COPD is a well-known risk factor for lung cancer, independent of smoking behavior. By ... more Background COPD is a well-known risk factor for lung cancer, independent of smoking behavior. By investigating the retrospective National Health Insurance Service-National Sample Cohort (NHIS-NSC) in Korea, this study attempted to prove the hypothesis that COPD is a risk factor for major cancers developing outside of the lungs. We also aimed to investigate the environmental factors associated with the development of lung cancer in COPD patients. Methods This study analyzed data from the NHIS-NSC over a 12-year period. Among the 514,795 subjects in the NHIS-NSC, 16,757 patients who were diagnosed with any cancer from 2002 to 2003 were excluded. This cohort enrolled six arms consisting of never-smokers without COPD (N = 313,553), former smokers without COPD (N = 41,359), smokers without COPD (N = 112,627), never-smokers with COPD (N = 7789), former smokers with COPD (N = 1085), and smokers with COPD (N = 2677). Results Incident rate of lung cancer per 100,000 person-year was higher ac...
Background COPD is a well-known risk factor for lung cancer, independent of smoking behavior. By ... more Background COPD is a well-known risk factor for lung cancer, independent of smoking behavior. By investigating the retrospective National Health Insurance Service-National Sample Cohort (NHIS-NSC) in Korea, this study attempted to prove our hypothesis that COPD is a risk factor for major cancers developing outside of the lungs. We also aimed to investigate the environmental factors associated with the development of lung cancer in COPD patients. Methods This study analyzed data from the NHIS-NSC over a 12-year period. Among the 514,795 subjects in the NHIS-NSC, 20,837 patients who were diagnosed with any cancer from 2002 to 2003 were excluded. Finally, this cohort enrolled four arms, the healthy control group (N=127,884), never-smokers with COPD (N=29,799), former smokers with COPD (N=3,267), and smokers with COPD (N=8,335). Results Over a 12-year period, lung cancer developed in 1.27% of the never-smokers with COPD, 2.97% of the former smokers with COPD, and 4.79% of smokers with C...
The ratio of serum leptin to adiponectin (L/A ratio) could be used as a marker for insulin resist... more The ratio of serum leptin to adiponectin (L/A ratio) could be used as a marker for insulin resistance. However, few prospective studies have investigated the impact of L/A ratio on improvement of metabolic components in high-risk individuals with metabolic syndrome. We examined the association between L/A ratio and the regression of metabolic syndrome in a population-based longitudinal study. A total of 1017 subjects (431 men and 586 women) with metabolic syndrome at baseline (2005-2008) were examined and followed (2008-2011). Baseline serum levels of leptin and adiponectin were analyzed by radioimmunoassay. Area under the receiver operating characteristics curve (AUROC) analyses were used to assess the predictive ability of L/A ratio for the regression of metabolic syndrome. During an average of 2.8 years of follow-up, metabolic syndrome disappeared in 142 men (32.9%) and 196 women (33.4%). After multivariable adjustment, the odds ratios (95% confidence interval) for regression of ...
We aimed to evaluate obesity, a risk factor of metabolic syndrome, and its association with prost... more We aimed to evaluate obesity, a risk factor of metabolic syndrome, and its association with prostatic enlargement in a retrospective cohort in Korea. Baseline data were obtained from the Korean Genome and Epidemiology Study on Atherosclerosis Risk of Rural Areas in the Korean General Population (KoGES-ARIRANG). Between March 2015 and November 2015, 2,127 male participants of KoGES-ARIRANG were invited to the Korean Prostate Health Council Screening Program, and 602 participants underwent urological examination, including serum prostate specific antigen measurement and transrectal ultrasonography, and completed the International Prostate Symptom Score questionnaire. The data for 571 participants were analyzed, after excluding 31 men who had a history of prostatic disease or testosterone replacement, or had undergone a prior prostatic surgery or procedure. Among components of metabolic syndrome, waist circumference had a statistically significant linear correlation with incremental in...
The fatty liver index (FLI), calculated from serum triglyceride, body mass index, waist circumfer... more The fatty liver index (FLI), calculated from serum triglyceride, body mass index, waist circumference, and gamma-glutamyltransferase, is considered a surrogate marker of nonalcoholic fatty liver disease (NAFLD). We investigated whether FLI predicts the development of diabetes mellitus (DM) and assessed the predictive ability of FLI for new onset of DM in a prospective population-based cohort study.We analyzed a total of 2784 adults (944 men and 1840 women) aged 40 to 70 years without DM at baseline. Participants were classified according to FLI values into 3 groups: FLI < 30, no NAFLD; 30 ≤ FLI ≤ 59, intermediate NAFLD; and FLI ≥ 60, participants with NAFLD. The area under the receiver-operating characteristic curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were calculated to determine whether FLI improved DM risk prediction.During a mean of 2.6 years follow-up, 88 (3.16%) participants developed DM. The odds ratio analyzed from...
The ratio of aspartate aminotransferase (AST) to alanine aminotransferase (ALT) is of great inter... more The ratio of aspartate aminotransferase (AST) to alanine aminotransferase (ALT) is of great interest as a possible novel marker of metabolic syndrome. However, longitudinal studies emphasizing the incremental predictive value of the AST-to-ALT ratio in diagnosing individuals at higher risk of developing metabolic syndrome are very scarce. Therefore, our study aimed to evaluate the AST-to-ALT ratio as an incremental predictor of new onset metabolic syndrome in a population-based cohort study. The population-based cohort study included 2276 adults (903 men and 1373 women) aged 40-70 years, who participated from 2005-2008 (baseline) without metabolic syndrome and were followed up from 2008-2011. Metabolic syndrome was defined according to the harmonized definition of metabolic syndrome. Serum concentrations of AST and ALT were determined by enzymatic methods. During an average follow-up period of 2.6-years, 395 individuals (17.4%) developed metabolic syndrome. In a multivariable adjust...
Journal of preventive medicine and public health = Yebang Uihakhoe chi, 2016
C-reactive protein (CRP), an inflammatory biomarker, has been widely used as a preclinical marker... more C-reactive protein (CRP), an inflammatory biomarker, has been widely used as a preclinical marker predictive of morbidity and mortality. Although many studies have reported a positive association between CRP and mortality, uncertainty still remains about this association in various populations, especially in rural Korea. A total of 23 233 middle-aged participants (8862 men and 14 371 women) who were free from cardiovascular disease, cancer, and acute inflammation (defined by a CRP level ≥10 mg/L) were drawn from 11 rural communities in Korea between 2005 and 2011. Blood CRP concentration was analyzed as a categorical variable (low: 0.0-0.9 mg/L; intermediate: 1.0-3.0 mg/L; high: 3.1-9.9 mg/L) as well as a continuous variable. Each participant's vital status through December 2013 was confirmed by death statistics from the National Statistical Office. Cox proportional hazard models were used to assess the independent association between CRP and mortality after adjusting for other ...
Osteoporosis is a progressive bone disease that is characterized by a decrease in bone mass densi... more Osteoporosis is a progressive bone disease that is characterized by a decrease in bone mass density and destruction of microstructure, which can lead to an increased risk of fracture. Although many studies have been published about the relationship between end-stage renal disease and osteoporosis, research on the relationship between proteinuria and the prevalence of osteoporosis is still lacking. We assessed 91 postmenopausal women with type 2 diabetes who visited our hospital from January 2009 to January 2012. Among 91 patients, the prevalence of osteoporosis and osteopenia was 35.2% (32 cases) and 32.9% (30 cases) according to bone mineral density. The patients with microalbuminuria and macroalbuminuria (urine albumin-to-creatinine ratio [UACR] ≥ 30) had a significantly higher incidence of osteoporosis compared to subjects with normoalbuminuria (P<0.05). This study indicates that UACR may be a useful biomarker for increased risk of osteoporosis in postmenopausal women with typ...
Clinica chimica acta; international journal of clinical chemistry, 2015
It has been reported that stable isotope ratios can be used as biomarkers for animal protein inta... more It has been reported that stable isotope ratios can be used as biomarkers for animal protein intake. Meat consumption and high protein intake could be risk factors for metabolic disorders. We investigated whether the stable isotope ratios of carbon and nitrogen are associated with metabolic syndrome. We conducted a cross-sectional study of 399 subjects (233 men and 166 women). Hair samples from 399 subjects were measured for stable isotope ratios of carbon (δ(13)C) and nitrogen (δ(15)N). The δ(15)N values progressively increased with the number of components of the metabolic syndrome present in study subjects (P for trend 0.047). In multivariable models, δ(15)N values were positively associated with the presence of metabolic syndrome (odds ratio, 1.53; 95% confidence interval, 1.09-2.14), whereas δ(13)C values were not (odds ratio, 0.97; 95% confidence interval, 0.72-1.30). The odds ratio (95% confidence interval) for metabolic syndrome comparing the highest to the lowest quartiles ...
This letter proposes a soft wearable robot with shape memory alloy (SMA)-based artificial muscle ... more This letter proposes a soft wearable robot with shape memory alloy (SMA)-based artificial muscle to assist with upper limb motion. The SMA-based artificial muscle was designed by embedding a bundle of SMA coil springs into a stretchable coolant vessel, which allows active cooling of the SMA bundles through coolant circulation. By attaching SMA-based artificial muscles to a soft wearable brace, a soft wearable robot was designed to assist elbow flexion and forearm supination/pronation. To support the activities of daily living (ADLs), the proposed robot can produce more than 3 Nm torque in the direction of elbow flexion. In addition, the proposed robot can increase the forearm supination/pronation ROM by an average of 15.7° for impaired users. Finally, to evaluate the effect of the assistance provided by the proposed system, experiments and system usability scale (SUS) assessments were conducted on a group of patients with stroke and spinal cord injuries (SCI). The results indicate that the robot improves not only the range of motion (ROM) but also the torque produced by the users. In addition, from the results of the user experiment, we found certain design issues that require further development for better performance of the robot.
This article proposes a shape memory alloy (SMA)-based artificial muscle that has an active cooli... more This article proposes a shape memory alloy (SMA)-based artificial muscle that has an active cooling system. An SMA coil spring is embedded into a stretchable coolant vessel, which allows active cooling of SMA through coolant circulation. The coolant effect has been investigated by measuring actuation speed. Integrating a thermomechanical model and heat transfer model between coolant and SMA, actuation times have been estimated. Based on these results, actuation performances that use four different coolants have been found out, and the mineral oil cooling case shows both contraction and extension times of less than 1 s to contract to over 35% of its initial length with 1 kg load. A soft wearable robot for assisting wrist motion has been designed by integrating multiple SMA muscles with a glove, wristband, and elbow anchor. Thanks to the advantages of the SMA coil spring actuator, the proposed robot is compliant and weight-balanced structure. The robot shows ranges of motion of 38°, 50°, 34°, and 35°, for flexion, extension, radial deviation, and ulnar deviation, respectively. In addition, the robot shows improved cyclic performance compared to a natural air-cooling system. Finally, its torque assistance and theamount of time needed to wear it have been analyzed with user tests.
Background The Korean Society of Hypertension has published the Korea Hypertension Fact Sheet 202... more Background The Korean Society of Hypertension has published the Korea Hypertension Fact Sheet 2020 to provide an overview of the magnitude and management status of hypertension and their recent trends. Methods The Fact Sheets were based on the analyses of Korean adults aged 20 years or older of the 2007–2018 Korea National Health and Nutrition Examination Survey (KNHANES) and the 2002–2018 National Health Insurance Big Data (NHI-BD). Results Currently, the population average of systolic/diastolic blood pressure was 118/76 mmHg in Korean adults aged 20 years or older showing little change in the recent decade. However, the number of people with hypertension increased steadily, exceeding 12.0 million. Indeed, the number of people diagnosed with hypertension increased from 3.0 million in 2002 to 9.7 million in 2018. During the same period, the number of people using antihypertensive medication increased from 2.5 million to 9.0 million, and the number of people adherent to treatment inc...
Background COPD is a well-known risk factor for lung cancer, independent of smoking behavior. By ... more Background COPD is a well-known risk factor for lung cancer, independent of smoking behavior. By investigating the retrospective National Health Insurance Service-National Sample Cohort (NHIS-NSC) in Korea, this study attempted to prove the hypothesis that COPD is a risk factor for major cancers developing outside of the lungs. We also aimed to investigate the environmental factors associated with the development of lung cancer in COPD patients. Methods This study analyzed data from the NHIS-NSC over a 12-year period. Among the 514,795 subjects in the NHIS-NSC, 16,757 patients who were diagnosed with any cancer from 2002 to 2003 were excluded. This cohort enrolled six arms consisting of never-smokers without COPD (N = 313,553), former smokers without COPD (N = 41,359), smokers without COPD (N = 112,627), never-smokers with COPD (N = 7789), former smokers with COPD (N = 1085), and smokers with COPD (N = 2677). Results Incident rate of lung cancer per 100,000 person-year was higher ac...
Background COPD is a well-known risk factor for lung cancer, independent of smoking behavior. By ... more Background COPD is a well-known risk factor for lung cancer, independent of smoking behavior. By investigating the retrospective National Health Insurance Service-National Sample Cohort (NHIS-NSC) in Korea, this study attempted to prove our hypothesis that COPD is a risk factor for major cancers developing outside of the lungs. We also aimed to investigate the environmental factors associated with the development of lung cancer in COPD patients. Methods This study analyzed data from the NHIS-NSC over a 12-year period. Among the 514,795 subjects in the NHIS-NSC, 20,837 patients who were diagnosed with any cancer from 2002 to 2003 were excluded. Finally, this cohort enrolled four arms, the healthy control group (N=127,884), never-smokers with COPD (N=29,799), former smokers with COPD (N=3,267), and smokers with COPD (N=8,335). Results Over a 12-year period, lung cancer developed in 1.27% of the never-smokers with COPD, 2.97% of the former smokers with COPD, and 4.79% of smokers with C...
The ratio of serum leptin to adiponectin (L/A ratio) could be used as a marker for insulin resist... more The ratio of serum leptin to adiponectin (L/A ratio) could be used as a marker for insulin resistance. However, few prospective studies have investigated the impact of L/A ratio on improvement of metabolic components in high-risk individuals with metabolic syndrome. We examined the association between L/A ratio and the regression of metabolic syndrome in a population-based longitudinal study. A total of 1017 subjects (431 men and 586 women) with metabolic syndrome at baseline (2005-2008) were examined and followed (2008-2011). Baseline serum levels of leptin and adiponectin were analyzed by radioimmunoassay. Area under the receiver operating characteristics curve (AUROC) analyses were used to assess the predictive ability of L/A ratio for the regression of metabolic syndrome. During an average of 2.8 years of follow-up, metabolic syndrome disappeared in 142 men (32.9%) and 196 women (33.4%). After multivariable adjustment, the odds ratios (95% confidence interval) for regression of ...
We aimed to evaluate obesity, a risk factor of metabolic syndrome, and its association with prost... more We aimed to evaluate obesity, a risk factor of metabolic syndrome, and its association with prostatic enlargement in a retrospective cohort in Korea. Baseline data were obtained from the Korean Genome and Epidemiology Study on Atherosclerosis Risk of Rural Areas in the Korean General Population (KoGES-ARIRANG). Between March 2015 and November 2015, 2,127 male participants of KoGES-ARIRANG were invited to the Korean Prostate Health Council Screening Program, and 602 participants underwent urological examination, including serum prostate specific antigen measurement and transrectal ultrasonography, and completed the International Prostate Symptom Score questionnaire. The data for 571 participants were analyzed, after excluding 31 men who had a history of prostatic disease or testosterone replacement, or had undergone a prior prostatic surgery or procedure. Among components of metabolic syndrome, waist circumference had a statistically significant linear correlation with incremental in...
The fatty liver index (FLI), calculated from serum triglyceride, body mass index, waist circumfer... more The fatty liver index (FLI), calculated from serum triglyceride, body mass index, waist circumference, and gamma-glutamyltransferase, is considered a surrogate marker of nonalcoholic fatty liver disease (NAFLD). We investigated whether FLI predicts the development of diabetes mellitus (DM) and assessed the predictive ability of FLI for new onset of DM in a prospective population-based cohort study.We analyzed a total of 2784 adults (944 men and 1840 women) aged 40 to 70 years without DM at baseline. Participants were classified according to FLI values into 3 groups: FLI < 30, no NAFLD; 30 ≤ FLI ≤ 59, intermediate NAFLD; and FLI ≥ 60, participants with NAFLD. The area under the receiver-operating characteristic curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were calculated to determine whether FLI improved DM risk prediction.During a mean of 2.6 years follow-up, 88 (3.16%) participants developed DM. The odds ratio analyzed from...
The ratio of aspartate aminotransferase (AST) to alanine aminotransferase (ALT) is of great inter... more The ratio of aspartate aminotransferase (AST) to alanine aminotransferase (ALT) is of great interest as a possible novel marker of metabolic syndrome. However, longitudinal studies emphasizing the incremental predictive value of the AST-to-ALT ratio in diagnosing individuals at higher risk of developing metabolic syndrome are very scarce. Therefore, our study aimed to evaluate the AST-to-ALT ratio as an incremental predictor of new onset metabolic syndrome in a population-based cohort study. The population-based cohort study included 2276 adults (903 men and 1373 women) aged 40-70 years, who participated from 2005-2008 (baseline) without metabolic syndrome and were followed up from 2008-2011. Metabolic syndrome was defined according to the harmonized definition of metabolic syndrome. Serum concentrations of AST and ALT were determined by enzymatic methods. During an average follow-up period of 2.6-years, 395 individuals (17.4%) developed metabolic syndrome. In a multivariable adjust...
Journal of preventive medicine and public health = Yebang Uihakhoe chi, 2016
C-reactive protein (CRP), an inflammatory biomarker, has been widely used as a preclinical marker... more C-reactive protein (CRP), an inflammatory biomarker, has been widely used as a preclinical marker predictive of morbidity and mortality. Although many studies have reported a positive association between CRP and mortality, uncertainty still remains about this association in various populations, especially in rural Korea. A total of 23 233 middle-aged participants (8862 men and 14 371 women) who were free from cardiovascular disease, cancer, and acute inflammation (defined by a CRP level ≥10 mg/L) were drawn from 11 rural communities in Korea between 2005 and 2011. Blood CRP concentration was analyzed as a categorical variable (low: 0.0-0.9 mg/L; intermediate: 1.0-3.0 mg/L; high: 3.1-9.9 mg/L) as well as a continuous variable. Each participant's vital status through December 2013 was confirmed by death statistics from the National Statistical Office. Cox proportional hazard models were used to assess the independent association between CRP and mortality after adjusting for other ...
Osteoporosis is a progressive bone disease that is characterized by a decrease in bone mass densi... more Osteoporosis is a progressive bone disease that is characterized by a decrease in bone mass density and destruction of microstructure, which can lead to an increased risk of fracture. Although many studies have been published about the relationship between end-stage renal disease and osteoporosis, research on the relationship between proteinuria and the prevalence of osteoporosis is still lacking. We assessed 91 postmenopausal women with type 2 diabetes who visited our hospital from January 2009 to January 2012. Among 91 patients, the prevalence of osteoporosis and osteopenia was 35.2% (32 cases) and 32.9% (30 cases) according to bone mineral density. The patients with microalbuminuria and macroalbuminuria (urine albumin-to-creatinine ratio [UACR] ≥ 30) had a significantly higher incidence of osteoporosis compared to subjects with normoalbuminuria (P<0.05). This study indicates that UACR may be a useful biomarker for increased risk of osteoporosis in postmenopausal women with typ...
Clinica chimica acta; international journal of clinical chemistry, 2015
It has been reported that stable isotope ratios can be used as biomarkers for animal protein inta... more It has been reported that stable isotope ratios can be used as biomarkers for animal protein intake. Meat consumption and high protein intake could be risk factors for metabolic disorders. We investigated whether the stable isotope ratios of carbon and nitrogen are associated with metabolic syndrome. We conducted a cross-sectional study of 399 subjects (233 men and 166 women). Hair samples from 399 subjects were measured for stable isotope ratios of carbon (δ(13)C) and nitrogen (δ(15)N). The δ(15)N values progressively increased with the number of components of the metabolic syndrome present in study subjects (P for trend 0.047). In multivariable models, δ(15)N values were positively associated with the presence of metabolic syndrome (odds ratio, 1.53; 95% confidence interval, 1.09-2.14), whereas δ(13)C values were not (odds ratio, 0.97; 95% confidence interval, 0.72-1.30). The odds ratio (95% confidence interval) for metabolic syndrome comparing the highest to the lowest quartiles ...
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