Holmium:YAG laser를 이용한 요관경하쇄석술의 초기 경험 : 기존의 쇄석술과의 결과 비교

구경완,노용수,김홍섭,양상국,나공찬 건국대학교 의과학연구소 2003 건국의과학학술지 Vol.13 No.-

Purpose: Holmium:YAG lasertripsy for the 33 patients with lower ureteral calculi compared the outcome with other results using Lithoclast and ultrasonic lithotripsy. Materials and Methods: Thirty-three patients with symptomatic urinary calculi underwent Holmium:YAG lasertripsy from March 1999 to December 2000. Twelve patients were treated with Ultrasonic lithotripsy and twenty-one patients with Lithoclast lithotripsy from April 1997 to October 1999. All calculi of the above patients were located in their lower ureters. The size of ureter stones was ranged from 3.5 mm to 12 mm (mean 6.54 mm). Results: The age of the patients ranged was from 19 to 62 years (me~n 35.7 years). After a single ureteroscopic lasertripsy calculi were conlpletely cleared in 83 % of the cases for the patients with lower ureter calculi. The immediate complications of lasertripsy were gross hematuria, fever, and flank pain. However in the long term follow up (up to 3 months after the procedures) there were no further complications, such as, vesicoureteral reflux or ureteral stricture. In other two lithotripsies Lithoclast and Ultrasonic lithotripsy accomplished calculi were completely cleared in 71 % and 74 % of cases respectively. But Holmium:Y AG lasertripsy is cleared in 94 % effectiveness. Holmium:Y AG lasertripsy is more effective than two other methods compared by stratified analysis that unmasking from confounding factors such as impacted situation. Conclusions: Lasertripsy with Holmium:Y AG laser is considered effective and safe procedure for the lower urinary calculi lithotripsy (Ultrasonic, Lithoclast).

Optimal Grip Span of A-type Pliers in a Maximum Gripping Task

Yong-Ku Kong,Jin Woo Jung,Sangmin Kim,Heewoong Jung,Hakje Yoo,Dae-Min Kim,Hyun-Sung Kang 대한인간공학회 2013 大韓人間工學會誌 Vol.32 No.6

Objective: The objective of this study is designing an optimal hand tool through maximum grip force study accordance to the hand grip span. Background: In order to prevent musculoskeletal diseases, studies on hand tool design are proceeding based on grip strength, finger force, and contribution of individual finger force on total grip strength. However, experimental apparatus using a tool that is actually used in work place was almost non-existent. Method: 19 males were participated in an experiment. Using the load cell inserted real plier, finger force, grip strength, and subjective discomfort rate of both hands (dominant and non-dominant) were measured in 5 different hand grip span(45mm, 50mm, 60mm, 70mm, and 80mm). Results: There was significant difference(p<0.001) of total grip strength, individual finger force and subjective discomfort rating according to various hand grip span(45, 50, 60, 70, and 80mm). Also, statistically significant different(p<0.001) was shown between the dominant hand and non-dominant hand. In addition, individual finger force in maximum grip was in order of middle finger, ring finger, index finger, and little finger. Conclusion: Optimal grip span of pliers that exerting maximum grip strength is 50~60mm. Application: This finding is expected to be used for designing proper pliers.

The Effects of Age, Gender, and Target Force Level on Controlled Force Exertion Tasks

Yong-Ku Kong,Sung Yong Lee,Dae-Min Kim,Kyeong-Hee Choi 대한인간공학회 2017 大韓人間工學會誌 Vol.36 No.1

Objective: The purpose of this study is to build basic data to systematically develop a hand function evaluation tool by determining the effects of age, gender and target force level on the difference in hand function according to the target force level. Background: Precise and objective evaluation of hand functionality is a very important factor in quantifying treatment progress in patients or elderly people, and in verifying treatment effects. However, most hand function evaluations lack objectivity and accuracy, and therefore it is difficult to properly treat patients according to the given situation. Method: Sixteen healthy subjects (eight elderly and eight young people) participated in this study to evaluate the effects of age, gender, and target force level on tracking performance through rRMSE in terms of the tracking force and actual exerted force, by carrying out a task of maintaining six different target force levels for 20 seconds. Results: The result of this experiment indicated that elderly people and women had a lower ability to maintain a certain level of force than young people and men by 16% and 10%, respectively. The target force level results showed that the tracking error of the lowest force level (5% MVC) was significantly higher than that of 15% MVC, which in turn showed a higher tracking error than that of the higher target force levels. Conclusion: The results of this study can thus be utilized to develop a rehabilitation program for elderly people or other patients. Application: The authors expect that the results of the present study will be valuable to develop a rehabilitation program and hand function evaluation tool.

A Design of Pliers in the Maximum Gripping Tasks

( Yong Ku Kong ),( Hyun Sung Kang ),( Dae Min Kim ),( Kyeong Hee Choi ) 한국감성과학회 2014 춘계학술대회 Vol.2014 No.-

Although automation of manufacturing environment, workers had to participated in most of processes and did manual task by using hand tools. Excessive use of hand tools also induced the WMSDs (i.e. carpal tunnel syndrome). Thus, optimal hand tool design for efficient use of grip strength is important factors for reducing the load on particular human body. In this study, a revised plier which can change gap from 45 to 80mm was applied to estimate grip strength, and resultant force. In the maximum gripping tasks, results showed that the effect of grip span on the total grip strength was statistically significant in the maximum gripping task (i.e. the 60mm grip span had a significantly higher total grip strength than the other grip spans). For resultant force task, the 60mm grip spans showed also significantly higher resultant force. The lowest subjective discomfort was observed in the 50mm span. So, 60mm grip span was optimal grip span for design optimal pliers. The results of this study are expected to be a basic guideline for optimal hand tool design so that reducing work-related musculoskeletal disorders related to hand tools

A comparison of muscle force between EMG and AnyBody Simulation

Yong-Ku Kong,Dae-Min Kim,Min-Tae Seo,Hyun-Sung Kang 대한인간공학회 2012 대한인간공학회 학술대회논문집 Vol.2012 No.11

Objective: The purpose of this study is to compare predicted force of each muscle between EMG and AnyBody simulation. Background: AnyBody provides a default human body model and users are able to customize that model for their research purpose. Users have to validate default human body models by comparing simulation data and real experimental data before customizing it. Methods: One subject participated to conduct a simple task which is lifting a dumbbell. While participants were doing the lifting task, forearm muscle activities (EMGs) were collected in this study. A lifting posture and weight of dumbbell was applied to AnyBody program to develop a simulation model. Results: The finding of this study showed that the measured muscle forces (EMG) of each muscle were not coincident with the findings of simulation model. The result of modeling data showed the tendency of the higher force than measured EMG data in a lifting dumbbell task. Discussion: The reason of discrepancy between AnyBody simulation and EMG analysis may different anthropometric data which were used in AnyBody simulation with actual participants" anthropometric data. Therefore, default models in AnyBody might need to be modified to acquire a similar result of experiment.

The relationship between hand anthropometrics, total grip strength and individual finger force for various handle shapes

Kong, Yong-Ku,Kim, Dae-Min Taylor Francis 2015 International journal of occupational safety and e Vol.21 No.2

Evaluation of pliers in a maximum gripping task

Yong-Ku Kong,Min-Tae Seo,Ji-Soo Kim,Hyun-Sung Kang 대한인간공학회 2013 대한인간공학회 학술대회논문집 Vol.2013 No.5

Objective: The objective of this study is to derive the optimal grip span of pliers in a maximum gripping task. Background: Although many previous studies have been performed for I-Type and cylinder-type handles and evaluated their various grip span size, there are only few studies regarding on A-Type handles such as pliers. Methods: A total of 25 males participated in this experiment and conducted maximum gripping task using custom-made pliers with three grip spans (50, 70, and 90㎜). The effects of grip spans on grip strength, muscle activity, and subjective discomfort were analyzed. Results: The experimental results showed that total grip strength of 50㎜ grip span had significantly higher than another grip spans. Subjective discomfort showed that the discomfort rating of radius side of the palm was higher than most other parts, significantly. The %MVC of the muscle has no significant difference in three grip span. Conclusion: It was recommended to use the 50mm grip span to exert the maximum grip strength with similar muscle activities in uses of pliers. Application: This finding is expected to be used as the basic data for designing proper pliers.

A Design of Pliers in the Maximum Gripping Tasks

Yong-Ku Kong,Hyun-Sung Kang,Dae-Min Kim,Kyeong-Hee Choi 대한인간공학회 2014 대한인간공학회 학술대회논문집 Vol.2014 No.5

Although automation of manufacturing environment, workers had to participated in most of processes and did manual task by using hand tools. Excessive use of hand tools also induced the WMSDs (i.e. carpal tunnel syndrome). Thus, optimal hand tool design for efficient use of grip strength is important factors for reducing the load on particular human body. In this study, a revised plier which can change gap from 45 to 80mm was applied to estimate grip strength, and resultant force. In the maximum g ripping tasks, results showed that the effect of grip span on the total grip strength was statistically significant in the maximum gripping task (i.e. the 60mm grip span had a significantly higher total grip strength than the other grip spans). For resultant force task, the 60mm grip spans showed also significantly higher resultant force. The lowest subjective discomfort was observed in the 50mm span. So, 60mm grip span was optimal grip span for design optimal pliers. The results of this study are expected to be a basic guideline for optimal hand tool design so that reducing work-related musculoskeletal disorders related to hand tools

The effects of the Aging on Hand Strength and Ability to Control Force

Yong-Ku Kong(공용구),Dae-Min Kim(김대민),Sung-Yong Lee(이성용),Kyeong-Hee Choi(최경희) 대한산업공학회 2015 대한산업공학회 춘계학술대회논문집 Vol.2015 No.4

Evaluation of Gender Effect in Various Pliers' Grip Spans for Maximum Isometric Grasping Tasks

Yong-Ku Kong,Dae-Min Kim,Ji-Soo Park,Sung-Yong Lee,Kyeong-Hee Choi,Kyung Ran Kim 대한인간공학회 2014 大韓人間工學會誌 Vol.33 No.6

Objective: The purpose of this study was to evaluate the effect of gender (male, female) and grip spans (45, 50, 60, 70, 80mm) on total grip strength, resultant force, finger force and subjective discomfort ratingI. Background: In order to prevent musculoskeletal disorders, studies of hand tools need to be preceded based on grip strength, finger force, and subjective discomfort rating. However, experimental apparatus using tools such as pliers that reflect the actual work place was almost non-existent. Method: Fifty-Two (26 males and 26 females) participants were recruited from the student population. In this study, a pair of revised pliers, which can change grip span from 45 to 80mm was applied to estimate total grip strength, resultant force and individual finger forces. All participants were asked to exert a maximum grip force with three repetitions, and to report the subjective discomfort rating for five grip spans of pliers (45, 50, 60, 70, 80mm). Results: There were significant differences of total grip strength, resultant force, individual finger forces and subjective discomfort rating according to grip span. The lowest total grip strength was obtained from the grip span of 80mm for both genders. For resultant force, the highest resultant force was exerted at grip spans of 50, 60 and 70mm for females and 50 and 60mm for males. The lowest subjective discomfort rating was observed in the 50mm for both genders. Conclusion: Based on the result, 50mm and 60mm grip spans which provide the highest force and lowest discomfort rating might be recommendable for the male and female pliers users. Application: The findings of this study can provide guidelines on designing a hand tool to help to reduce hand-related musculoskeletal disorders and obtain better performance.