• 한국정밀공학회지
• /
• 제20권3호
• /
• pp.202-209
• /
• 2003

We succeeded to build a cost effective assistance robotic arm with a compact and lightweight body. The robotic arm has three joints, and the tip of robotic arm to install tools consists of a closed link mechanism, which consisted of two actuators and several links. The robotic arm has been made possible by the use of actuators typically used in radio control devices. The controller of the robotic arm consists of a single chip PIC only. The robotic arm has a friendly user interface, as the operators are aged and disabled in most cases. The operator can manipulate the robotic arm by voice commands or by pressing a push button. The robotic arm has been successfully prototyped and tested on an elderly patient to assist with eating. The results of field test were satisfactory.

• 대한두개안면성형외과학회지
• /
• 제10권2호
• /
• pp.131-134
• /
• 2009

저자들은 보편적으로 보존치료가 불가능 하여 관혈적 정복술이 필요한 하악의 관절돌기골절 증례에서 당뇨, 고혈압의 병력, 고령으로 인한 절개 및 박리, 전신마취 시간증가로 발생할 수 있는 합병증을 줄이기 위해 우선적으로 시행한 형광투시하의 비관혈적 도수정복만으로 정확한 정복에 성공할 수 있었고 이후 골 유합까지 유지하여 만족스런 결과를 얻었기에 보고하는 바이다.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2005년도 제25회 추계학술대회논문집
• /
• pp.169-172
• /
• 2005

추진기관의 우발 점화를 방지해주는 점화안전장치의 성능 시험 결과를 기술하였다. 고전적인 형태의 기계식 안전장치와 보다 진보된 개념의 전기기계식 점화안전장치의 밀폐용기 시험 결과 및 점화기 적용 시험 결과를 제시하였고, 두 종류의 점화안전장치의 성능 비교 시험 결과 작동시간 측면에서 전기기계식 점화안전장치가 다소 유리한 것으로 판단되었다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1992년도 춘계학술대회 논문집
• /
• pp.185-189
• /
• 1992

This paper prsents an end-point control of a one-link flexible arm with a payload by using closed loop control. Tip position of arm is shifted by the base motion according to DC servomotor, whivh is driven by a feedback signal composed of the tip displacement and the estimated tip velocity. The shifting problem of the arm from initial position to desired position is considered by the variation of the displacement gain Gd and velocity agin Gv. Theoretical results are obtained by applying the method of the Laplace transform to the governing equations and the method of numerical inversion. This system is composed of a flexible arm with payload, DC servomotor, and a ballscrew mechanism. The flexible arm is mounted on a mobile stage driven by a servomotor and ballscrew. In controlling the tip displacement of flexible arm, the fundamental bode vibration is supressed more rapidly with an increase of the velocity feedback gain Gv and the feedback displacemenmt gain Gd. Theretical responses are approximately in good agreement with those obtained experimentally.

• PNF and Movement
• /
• 제13권2호
• /
• pp.95-102
• /
• 2015

Purpose: The purpose of this study was to analyze the effect of arm flexion patterns of proprioceptive neuromuscular facilitation on muscle activation in the contralateral lower extremity. Open kinematic chain and closed kinematic chain positions were used. Methods: This study used an electromyogram (MP150, Biopac Systems, USA) to measure muscle activation in 20 healthy male students. Comparative analysis was completed on muscle activation of the vastus lateralis, biceps femoris, tibialis anterior, and gastrocnemius of the contralateral lower extremity. Open kinematic chain and closed kinematic chain positions were used with a unilateral arm flexion-abduction-external rotation pattern. Paired t-tests using the SPSS 12.0 for Windows analyzed the data produced by the electromyogram. Results: There was a statistically significant difference in muscle activation in the biceps femoris, gastrocnemius, and tibialis anterior when the open kinematic chain and closed kinematic chain positions were compared (p < 0.05). Conclusion: The biceps femoris, gastrocnemius, and tibialis anterior muscles showed greater muscle activation in the closed kinematic chain position when compared to the open kinematic chain position.

• Journal of Advanced Marine Engineering and Technology
• /
• 제32권2호
• /
• pp.343-350
• /
• 2008

In this paper, a six degree-of-freedom robot arm which is very light but capable of delivering heavy loads was studied. The proposed robot arm has much higher load capacity than conventional robot arms actuated by motors with speed reducers such as the harmonic drive since a new type of robot actuator based on a closed chain mechanism driven by the ball screw was adopted. Analysis on the design scheme and on the mechanism of the joint actuator of the robot arm were made. Since the robot arm was designed very light, it has deflection in the links. To analyze this, a finite element analysis on the structure of the designed robot links was made using ANSYS software. Verifying experiments on the performance of high load capacity of the robot arm was performed by loading heavy weights on the robot arm. Through experiments. the correctness of the numerical analysis was also verified.

• 대한두개안면성형외과학회지
• /
• 제14권2호
• /
• pp.96-101
• /
• 2013

Background: Among facial fractures, nasal bone fracture, zygomatic arch fracture and mandibular subcondyle fracture take a large portion. Among surgical operations for nasal bone fracture, zygomatic arch fracture and mandibular subcondyle fracture, closed reduction has been generally used but, unlike open reduction, there is a problem in evaluating its accuracy of reduction. Methods: An assessment was made from October 2011 until April 2013 prospectively on 37 patients. For all the operations, closed reductions were executed in a conventional way and simultaneously using C-Arm to verify the reduction of fractures. Two images of plain radiography, one taken before operation and another one taken one day after the operation, were compared. After obtaining images of plain radiography using C-Arm immediately after the correction upon operation, they were compared with the images of plain radiography taken one day after the operation. Results: The fracture reductions of 26 patients among 27 nasal fracture patients were satisfactory but one patient showed a marginal overcorrection of less than 1 mm. The fracture reductions of 7 patients among 8 zygomatic arch fracture patients were satisfactory but one patient showed a marginal undercorrection of less than 2 mm. All of two mandibular subcondyle fracture patients showed less than 2 mm undercorrection. Conclusion: Closed reduction guided by C-Arm for nasal bone fracture, zygomatic arch fracture and mandibular subcondyle fracture was clinically useful because it could make a real-time assessment on fractured areas and add immediate corrections during the operation.

• Journal of Chest Surgery
• /
• 제12권3호
• /
• pp.174-182
• /
• 1979

This is a report on four cases of successful surgical correction of coarctation of the aorta [COA] in Department of the Thoracic & Cardiovascular Surgery, Hanyang University Hospital. The first case was a postductal type of coarctation of the aorta associated with Patent ductus arteriosus [PDA], Persistent left superior vena cava [LSVC] and richly developed collateral circulation. Blood pressure was measured to be hypertensive at the arm, but hypotensive at the legs. The coarctation of the aorta was corrected with following procedure: Partial resection of the aortic wall with diaphragmatic structure lust above and below the coarctating line of the aorta, and then the defect of the aortic wall was closed by lateral aortographic suture. PDA was closed by ligation procedure. The second case a preductal type of coarctation of the aorta associated with PDA, LSVC, ventricular septal defect [VSD] and poorly developed collateral circulation. Normal blood pressure was measured at the arm, but hypotension was observed at the legs. Correction of coarctation of the aorta was performed under the establishment of tube bypass because of poor collateral circulation. After resection of coarctating short segment, end to end anastomosis was performed without any tension. PDA was closed by division procedure. Simple suture closure of VSD was performed by open heart surgery two weeks after correction of COA. The third case was a long segment COA without any other anomaly. Blood pressure was measured to be hypertensive at the arm, but hypotensive at the legs. Vascular prosthesis was performed using Teflon graft tube after resecting coarctating long segment [6.5 cm] of the aorta. The fourth case was a long segment COA associated with aortic insufficiency and richly developed collateral circulation. Normal blood pressure was measured at the arm, but hypotension was observed at the legs. Vascular prosthesis was performed using Teflon graft tube after resecting coarctating long segment [6.0 cm] of the aorta. Both blood pressure and peripheral pulse on the arm and the legs returned to normal postoperatively in all patients.

• 대한물리의학회지
• /
• 제6권2호
• /
• pp.215-223
• /
• 2011

Purpose: The purpose of this study was to determine the effect of leg muscle activation by applying proprioceptive neuromuscular facilitation (PNF) arm patterns to unilateral upper extremities under the condition of both open and closed kinetic chains in a seated position. Methods: Twenty-two healthy subjects participated in this study. Four PNF patterns were applied to each subject's unilateral upper extremity. EMG data were collected from the vastus medialis, biceps femoris, tibialis anterior and gastrocnemius. The measured EMG data were digitized and processed to root mean square (RMS) and expressed as percentage maximal voluntary isometric contraction (%MVIC). The data were analyzed using two-way analysis of variance (ANOVA) with repeated measures to determine the statistical significance. Results: The results of this study were summarized as follows: Firstly, in comparison to muscle activation of the biceps femoris, there was a significant increase in the D2 flexion pattern when it was compared with D2 extension pattern and when it was compared with D1 flexion pattern (p<.05). Secondly, there was a significant increase in the muscle activation of the vastus medialis and tibialis anterior with a closed kinetic chain rather than an open kinetic chain (p<.05). Conclusion: In conclusion, in order to increase muscle activation of the biceps femoris, the D2 flexion pattern can be applied, regardless of kinetic chain. In addition, in order to increase muscle activation of the vastus medialis and tibialis anterior, four arm patterns can be applied with a closed kinetic chain.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
• /
• pp.607-612
• /
• 1992

This paper presents a tip position control of a single-link flexible arm with a payload by using closed loop control. The shifting problem of the arm from the initial position to desired position is considered by the variation of the displacement gain $G_{p}$ and velocity gain $G_{v}$. The system is composed of a flexible arm with payload, DC servomotor, and a ballscrew mechanism. The flexible arm is mounted on a mobile stage driven by a servomotor and ballscrew. As a result, the increase of the displacement and velocity gain respectively comes to the reduction of tip vibration. Theoretical results are approximately in good agreement with those obtained experimentally.y.y.