• 대한족부족관절학회지
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• 제22권4호
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• pp.161-165
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• 2018

Purpose: A distal tibiofibular syndesmosis injury with an ankle fracture is usually fixed with syndesmotic screws. Knotless Tightrope$^{(R)}$ has been used as an alternative procedure because of the fewer reported complications. Therefore, this study compared the two surgeries. Materials and Methods: Forty-two patients, who underwent syndesmotic screw fixation, and 34 patients, who underwent Knotless Tightrope$^{(R)}$ fixation for distal tibiofibular syndesmosis injury from February 2014 to February 2016, were analyzed retrospectively. The visual analogue scale (VAS) score, American Orthopaedic Foot and Ankle Society (AOFAS) score, range of motion of ankle at 1 year after surgery, tibiofibular clear space, and tibiofibular interval at preoperative, postoperative and 1 year after surgery were investigated. Results: The VAS score, AOFAS score and radiographs were similar in the two groups. Knotless Tightrope$^{(R)}$ showed better results in complications and plantarflexion. Conclusion: Knotless Tightrope$^{(R)}$ fixation is a useful treatment that does not show a difference in fixation strength and clinical outcome. Knotless Tightrope$^{(R)}$ fixation also has an advantage in the range of motion and complications.

• 한국기계가공학회지
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• 제19권8호
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• pp.81-87
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• 2020

A stable rotational-to-linear motion transformation structure using a driving mechanism with 2 degrees of freedom was developed for an orthogonal mechanism to prevent the interference of each axis in 2D motion. In this mechanism, a step motor was used for precise position control. This structure was developed to maneuver workparts in micro particle blast machining experiments. To determine the real-time performance of micro particle blast machining, the control, input, and output were operated simultaneously and precise position control was implemented, using a timer interrupt with multiple execution codes. The two step motors obtained precise position control by removing backlash with a ball-screw mechanism. The device has menu-type control codes for user-friendliness, and real-time sequence control was simultaneously adopted for user control input.

• Korea-Australia Rheology Journal
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• 제13권3호
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• pp.141-148
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• 2001

In this research, experimental studies leave been performed on the hydrodynamic interaction between a spherical particle and a plane wall by measuring the force between the particle and wall. To approach the system as a resistance problem, a servo-driving system was set-up by assembling a microstepping motor, a ball screw and a linear motion guide for the particle motion. Glycerin and dilute solution of polyacrylamide in glycerin were used as Newtonian and non-Newtonian fluids, respectively. The polymer solution behaves like a Boger fluid when the concentration is 1,000 ppm or less. The experimental results were compared with the asymptotic solution of Stokes equation. The result shows that fluid inertia plays all important role in the particle-wall interaction in Newtonian fluid. This implies that the motion of two particles in suspension is not reversible even in Newtonian fluid. In non-Newtonian fluid, normal stress difference and viscoelasticity play important roles as expected. In the dilute solution weak shear thinning and the migration of polymer molecules in the inhomogeneous flow field also affect the physic of the problem.

• Clinics in Shoulder and Elbow
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• 제19권1호
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• pp.43-47
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• 2016

Many types of osteotomy have been proposed for the treatment of cubitus varus deformity of the elbow, and various methods for fixation of the osteotomy site have also been described. However, no method has been perfect. We treated two cases of cubitus varus elbow deformity with step-cut osteotomy using a new fixation method with two crossing screws and an anatomically designed locking plate. Active assisted elbow range of motion (ROM) exercise was permitted at postoperative 3 days, after removal of the drainage. Preoperative and postoperative humerus-elbow-wrist angles and ranges of motion of the two patients were compared. At 3 months followup, each patient had recovered the preoperative elbow ROM, and achieved the complete bony union of the osteotomy site and proper correction of the cubitus varus deformity. In addition, the appropriate remodeling of the lateral bony protrusion was observed. Therefore, we introduce a new fixation method for achievement of stable fixation allowing immediate postoperative elbow motion after corrective osteotomy for cubitus varus deformity in young adults.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.209-214
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• 2003

We developed a new type of human-sized BWR (biped walking robot), named KUBIR1 which is driven by the closed-chain type of actuator. A new type of the closed-chain actuator for the robot is developed, which is composed of the four-bar-link mechanism driven by the ball screw which has high strength and high gear ratio. Each leg of the robot is composed of 6 D.O.F joints. For front walking, three pitch joints and one roll joint at the ankle. In addition to this, one yaw joint for direction change, and another roll joint for balancing the body are attached. Also, the robot has two D.O.F joints of each hand and three D.O.F. for eye motion. There are three actuating motors for stereo cameras for eyes. In all, a 18 degree-of-freedom robot was developed. KUBIR1 was designed to walk autonomously by adapting small 90W DC motors as the robot actuators and batteries and controllers are on-boarded. The whole weight for Kubir1 is over 90Kg, and height is 167Cm. In the paper, the performance test of KUBIR1 will be shown.

• 대한기계학회논문집A
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• 제24권2호
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• pp.362-369
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• 2000

Via screw theory, a vibration mode can be geometrically interpreted as a pure rotation about the vibration center in a plane and as a twisting motion on a screw in a three dimensional space. In thi s paper, applying the conditions that can be used to diagonalize the stiffness matrix by a parallel axis congruence transformation, the vibration modes and frequency response of an elastically suspended optical disc drive have been analyzed. It is first shown that the system has one plane of symmetry, which enables one to decouple the complicated vibration modes into two sets of modes independent of each other. Having obtained the analytical solutions for the axes of vibrations, the frequency response for a given applied input force has been demonstrated. Most importantly, it has been explained that this research result could be used in the synthesis process of a linear vibration system in order to improve the frequency response.

• Journal of Yeungnam Medical Science
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• 제20권2호
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• pp.177-186
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• 2003

교통사고의 증가로 심한 경골 고평부 골절이 점진적으로 증가되는 양상이며, 경골 고평부 골절 후 동반손상의 적절한 치료, 해부학적 정복 및 견고한 고정, 조기 관절운동이 좋은 예후를 보이며 외상성 관절염을 줄일 수 있을 것으로 사료된다.

• 한국기계가공학회지
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• 제13권6호
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• pp.88-98
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• 2014

A moving mass on a skewed linear guideway model to analyze the friction-induced stick-slip behavior of ball-screw-driven slides is proposed. To describe the friction force, a friction coefficient function is modelled as a third-order polynomial of the relative velocity between the slide mass and a guideway. A nonlinear differential equation of motion is derived and an approximate solution is obtained using a perturbation method for the amplitudes and base frequencies of both pure-slip and stick-slip oscillations. The results are presented with time responses, phase plots, and amplitude plots, which are compared adequately with those obtained by Runge Kutta 4th-order numerical integration, as long as the difference between the static and kinematic friction coefficients is small. However, errors in the results by the approximate solution increase and are not negligible if the difference between the friction coefficients exceeds approximately 40% of the static friction coefficient.

• Clinics in Shoulder and Elbow
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• 제19권1호
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• pp.8-14
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• 2016

Background: The purpose of this study was to investigate the difference between two nailing approaches of intramedullary screw fixation, the retrograde nailing versus the anterograde nailing, on the radiological and clinical outcomes in patients with clavicle shaft fractures. Methods: From April 2002 to August 2014, we enrolled a total of 22 patients with clavicle shaft fractures to participate in this study. Twelve patients received retrograde intramedullary nailing and 10 received anterograde nailing. The average duration of follow-up was 12 months. In all the patients, we took follow-up radiographs of the anteroposterior and the axial views to assess the postoperative radiological outcomes. We measured the visual analogue scale (VAS) score, American Shoulder and Elbow Surgeons (ASES) score, and the range of motion (ROM). Results: Clinically, we did not find a statistically significant difference in the retrograde group and the anterograde group in terms of the duration to bone union, the VAS score the ASES score and the ROMs. Radiologically, we found that the difference in the clavicle shortening of the affected arm and the unaffected arm did not show a statistically significant difference at the immediate postoperative assessment. we found that the difference in the clavicle shortening of the affected arm between the immediate postoperative and the final follow-up value did not show a statistically significant difference. Conclusions: We found that both the retrograde nailing and the anterograde nailing gave a favorable outcome for clavicle shaft fractures. Although we saw evidence of clavicle shortening after intramedullary screw fixation, this was not a factor that influenced clinical outcome.

• 대한관절경학회지
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• 제13권3호
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• pp.254-258
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• 2009

경골 과간 융기부 골절은 슬관절의 뒤틀림, 과도한 굴곡 및 신전, 내반 및 외반 손상으로 인한 견열 골절의 형태로 발생을 하며 정확한 해부학적 정복이 이루어지지 않을 경우 슬관절의 불안정성과 관절 운동 제한을 초래할 수 있다. 최근 관절경을 이용한 정복과 다양한 고정 방법이 시행되고 있으며, 저자들은 이 중 견인 봉합술을 시행함에 있어서 도관 나사못을 이용한 터널을 만들어 기존에 시행되어지던 술기에 비해 보다 쉽고 편리하게 내고정을 얻을 수 있었으며, 이에 수술방법의 소개와 증례를 보고하고자 한다.