원위 경골 간부 골절에서 최소 침습적 경피적 금속판 고정술과 관혈적 금속판 고정술의 비교

유성호 ( Seong Ho Yoo ),안성준 ( Seong Jun Ahn ),송무호 ( Moo Ho Song ),김부환 ( Bu Hwan Kim ),이민수 ( Min Soo Lee ),박종하 ( Jong Ha Park ) 대한골절학회 2006 대한골절학회지 Vol.19 No.1

목적: 경골 원위부 골절의 치료에 있어 최소 침습적금속판 고정술과 관혈적 고정술에 대한 비교를 통한 효율성에 대한 연구고찰을 하고자 한다. 대상 및 방법: 2001년 6월부터 2004년 6월까지 경골 원위부 골절에 대하여 수술을 시행한 최소 1년 이상의 추시가 가능하였던 30예 중 최소 침습적 금속판 고정술을 시행한 15예를 A군, 관혈적 금속판 고정술을 시행한 15예를 B군으로 나누어 수술시간, 술 후 재활, 술 후 운동범위, 동통에 대하여 McLennan과 Ungersma의 기준을 이용한 임상평가, 술 후 염증반응에 대한 C-반응성 단백 및 술 후 합병증을 후향적으로 비교 분석하였다. 결과: A군과 B군의 수술시간은 각각 63분 (45∼105)/129분 (80∼120), 능동적 관절 운동가능시기는 8.3일 (6∼14)/15.8일 (13∼21), McLennan과 Ungersma의 기준에 의한 임상평가는 두 군 모두에서 대부분 양호 이상의 결과를 보였으나, B군에서는 보통 1예가 있었다. 술 후 3일, 7일째 각각 시행한 CRP는 A군에서는 4.0 mg% (범위: 0.9∼7.2)/0.5 mg% (0.1∼1.5), B군에서는 7.97 mg% (2.8∼14.6)/1.0 mg% (0.3∼1.6)로 A군에서 조직손상이 적고 회복이 빨랐다. 술 후 합병증으로는 A군에서는 표재성 감염 1예와 5도 이상의 족관절 외반변형 1예가 있었고, B군에서는 표재성 감염 1예, 감염성 불유합 1예와 10도 미만의 족관절 배굴장애를 보이는 경우가 2예 있었다. 결론: 경골 원위부 골절의 수술적 치료에서 최소 침습적 금속판 고정술이 관혈적 고정술에 비해 조직의 염증반응과 합병증이 적고 수술시간 및 술 후 재활 등에서 보다 효율적인 술식으로 사료된다. Purpose: To evaluate the efficacy of the surgical treatment through the comparison of MIPPO vs open plate fixation in the treatment of the distal tibia fracture retrospectively. Materials and Methods: 30 patients with distal tibia fracture from Jun. 2001 to Jun. 2004 were divided into two groups depending on the surgical method. Minimum follow up was 12 months. Group A consisted of 15 patients treated with MIPPO, Group B was 15 patients treated with open plate fixation. The clinical outcomes were evaluated retrospectively from operation time, rehabilitation, ROM, interval change of postoperative CRP to assess postoperative inflammatory reaction, postoperative complications and clinical result with the use of McLennan and Ungersma criteria. Results: There were no significant differences in clinical result by McLennan and Ungersma criteria in both groups. The postoperative 3 days and 7 days CRP were 4.0 mg% (0.9∼7.2)/0.5 mg% (0.1∼1.5) in group A and 7.97 mg% (2.8∼14.6)/1.0 mg% (0.3∼1.6) in group B, shows more minimal tissue injury and early recovery in group A. Operation time in group A was shorter than group B. Normal recovery of ROM was quicker in Group A. In complications, group A showed one superficial infection and one angular deformity and group B showed one superficial infection, one infected nonunion and two ankle stiffness. Conclusion: There were no significant differences in clinical result and bony union. MIPPO technique is superior to group B in view of the minimal tissue injury, complications, operation time and postoperative rehabilitation.

연속파형 Nd:YAG SM45C 레이저 용접의 결함 감소연구

유영태,오용석,노경보,신호준 朝鮮大學校 機械技術硏究所 2003 機械技術硏究 Vol.6 No.1

본 연구에서는 Nd:YAG 연속파형 레이저를 이용하여 레이저 용접시 레이저빔의 출력에 대한 레이저범의 이송속도를 변화시켜 심입용접을 실시했다. 열처리를 하지 않고 용접을 실시했을 경우 매우 조대한 기공이 많이 발생하였지만 열처리 후 용접을 실시했을 때는 몇몇 미세한 기공만 발생하였다. Present investigation reports on the effect of incorporating pre-heating on the mechanical properties of laser weldi'ng joints. The Nd:YAG laser in combination with the optical fiber increase the automation and the flexibility of a whole industry. The Nd:YAG laser welding process is one of the most advenced menufacturing technologies owing to its high sped and penetration. This paper describes the weldability of Sh4456 carbon steel fox machine structural use by Nd:YAG laser. Optical microscopy SEM were performed to observe the micro structures and to determine the structures of welded zone. In addtion, mechanical propreties, were measured by tensile test to evaluate the formablity of the welded specimen. The results show that proper selection of the control parameters for per-heating technique can result the porosity and cracking of the welding significantly, and improve the welded joints mechanical properties, such as higher tensile strength and better durability.

압박 고 나사로 치료한 대퇴골 전자부 골절 : 고정 실패의 인자에 대한 분석 Analysis of Factors associated with Failure of Fixation

유찬훈,김홍태,변영수,남준모,조영호,문성건 대한골절학회 2002 대한골절학회지 Vol.15 No.4

목 적 : 압박 고 나사로 치료한 대퇴골 전자부 골절의 고정 실패에 영향을 미치는 요소에 대하여 분석하고자 하였다. 대상 및 방법 : 1995년 5월부터 2000년 7월까지 대퇴골 전자부 골절을 압박 고 나사를 이용하여 치료하고 1년 이상 추시가 가능했던 97예를 대상으로 하였다. 골절의 분류는 Jensen 분류법을, 골다공증의 정도는 Singh 지수를 이용하였다. 술후 방사선 검사에서 경체각, 정복 상태, 지연 나사의 대퇴골 두 내 위치, tip-apex distance(TAD) 및 지연 나사의 활강 거리를 측정하였고 고정 실패에 미치는 영향을 통계학적으로 분석하였다. 결 과 : 97예 중 17예(17%)에서 고정 실패가 발생하였고 그 중 지연 나사의 과도한 활강으로인한 경우가 15례(15.4%), 골두 천공 1얘, 10도 이상의 외반 변형 1예였다. 고정 실패의 발생과 80세 이상의 고령, 불안정성 골절, telescoping 정복, 원위 골편의 내측 혹은 전방 전위, 대퇴골 두 내 지연 나사의 위치와 밀접한 관계가 있었다. 결 론 : 압박 고 나사를 이용한 대퇴골 전자부 골절의 치료에서 고정 실패를 방지하기 위해서는 정확한 정복이 필요하고 대퇴골 두 내에서 지연 나사의 전방 위치를 피하는 것이 좋을 것으로 사료된다. Purpose : This study was performed to analyze the significant factors that may affect failure of fixation in trochanteric fractures of the femur treated with the compression hip screw. Materials and Methods : From May 1995 to July 2000, the authors analyzed 97 cases of trochanteric fracture of the femur treated with the compression hip screw and followed more than one year. We classified the fracture type by Jensen's method. We used Singh index for the degree of osteroporosis. In the post-operative radiograph, we checked neck-shaft angle, state of reduction, position of the lag screw within the femoral head, tip-apex distance, and sliding distance of the lag screw. The relationship between these factors and failure of fixation was statistically analyzed. Results : There were 17 cases(17.5%) of failure of fixation ; 15 cases(15.4%) of excessive sliding of the lag screw, 1 case (1%) of cutting out of the lag screw, and 1 case (1%) of valgus malunion. There were significant relationship between failure of fixation and old age over 80 , unstable fracture, telescoping reduction, anterior or medial displacement of the distal fragment, and anterior placement of the lag screw within the femoral head. Conclusion : Accurate reduction and avoidance of the placement of the lag screw in the anterior part of the femoral head were important factors to prevent failure of fixation in trochanteric fractures of the femur treated with the compression hip screw.

마이크로그로브 형태에 따른 평활근 세포 운동 측정

유소영,박찬영,정석,김동익,이병붕,허세호,한동철,장준근 대한혈관외과학회 2002 Vascular Specialist International Vol.18 No.2

Purpose: The spreading, orientation, and chemotaxis the gradient of a chemoattractant of smooth muscle cells (SMCs) were studied on the micro-grooved substrata by the light, fluorescence and scanning electron microscopy. Method: Vertical-walled grooves were produced in silicon wafers by the micromachining technique. All grooves were 4~20㎛ deep and 10~80㎛ wide, SMCs were cultured on each microgroove and examined under stereo-microscope. Result: Cell clusters were markedly oriented by all the grooved substrata examined. Tim-lapse images acquired from CCD (Charge Coupled Device) showed that the grooves directed the migration of SMCs. There was no prominent difference in the migration speed of SMCs according to the grooves. All the cytoskeletal fibers were reoragnized in the same direction with grooves. Especially the alignments of microtubule and intermediate filaments were distinguished in the SMCs on the micro grooves. Conclusion: These results could be applied to the analysis of vascular restenosis and the development of artificial blood vessels.

레이저를 이용한 SM45C와 STS304의 이종금속용접

유영태,신호준 조선대학교 에너지.자원신기술연구소 2004 에너지·자원신기술연구소 논문지 Vol.26 No.2

For many years and primarily for economical reasons, Dissimilar Metal Welds have been used as transition joints in a variety of equipment and applications. But Dissimilar Metal Welds have several fabrication and metallurgical drawbacks that can often lead to in-service failures For example, the most pronounced fabrication faults are hot cracks. Laser welding techniques have been characterised for various materials. In this paper, the laser weldability of STS304 stainless steel and SM45C at dissimilar metal welds using a continuous wave Nd:YAG laser are experimentally investigated. An experimental study was conducted to determine effects of welding parameters, on eliminating or reducing the extent welding zone formation at dissimilar metal welds and to optimize those parameters that have the most influence parameters such as focus length, Power, beam speed, shielding gas, and wave length of laser were tested.

고출력 CW Nd:YAG 레이저를 이용한 인코넬 600의 용접 특성

유영태,신호준,임기건 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.6

The welding characteristics of Inconel 600 Alloy using a continuous wave Nd:YAG laser are experimentally investigated. The major process parameters studied in the present laser welding experiment were the positions of focus, laser power and travel speed of laser beam. We measured the fusion zone size and its shape using an optical microscope for the observation of cross-sectional area. We performed two tests regarding the tension and the micro hardness for welding quality estimation. Then we measured residual stress in welds by electronic speckle pattern interferometry(ESPI). In conclusion, the optimum butt welding process parameters were 0.5mm focus position, 1.6kW laser power, 1m/min travel speed and 5.5ℓ/min assist gas discharge.

CW Nd:YAG 레이저에 의한 이종금속 용접공정변수

유영태,신호준,나기대 조선대학교 에너지.자원신기술연구소 2004 에너지·자원신기술연구소 논문지 Vol.26 No.1

For many years and primarily for economical reasons, Dissimilar Metal Welds have been used as transition joints in a variety of equipment and applications. But Dissimilar Metal Welds have several fabrication and metallurgical drawbacks that can often lead to in-service failures. For example, the most pronounced fabrication faults are hot cracks.Laser welding techniques have been characterised for various materials. In this paper, the laser weldability of STS304 stainless steel and Inconel 600 at dissimilar metal welds using a continuous wave Nd:YAG laser are experimentally investigated. Inconel 600 is being used in a steam generator tubing of pressurized water reactor(PWR) exposed to some corrosion. Stress corrosion cracking can occur on this material. An experimental study was conducted to determine effects of welding parameters, on eliminating or reducing the extent welding zone formation at dissimilar metal welds and to optimize those parameters that have the most influence parameters such as focus length, power, beam speed, shielding gas, and wave length of laser were tested.

CW Nd:YAG레이저를 이용한 금형 재료의 표면열처리

유영태,신호준,장우양 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.5

Laser heat treatment is an effective technique used to improve the tribological properties and also to increase the service life of automobile components such as camshafts, crankshatfs, lorry brake drums and gears. High power CO₂ lasers and Nd:YAG lasers are employed for localized hardening of materials and hence are of potential application in the automobile industries. The heat is conducted rapidly into the bulk of the specimen causing self-quenching action to occur and the formation of matrensitic structure. In this investigation, the microstructrual features occurring in Nd:YAG laser hardening SM45C and STD_(11) steel are discussed with the use of optical microscopic and scanning electron microscopic analysis. Moreover, This paper describes the optimisation of the processing parameters for maximum hardened depth of SM45C and STD_(11) steel specimens of 10mm thickness by using CW:YAG laser.

포도종실 추출물이 Methylcellulose 필름 성질에 미치는 영향

유승모,박준서,정하열,심재용,김병호,박장우 한국산업식품공학회 2003 산업 식품공학 Vol.7 No.4

The film with methylcellulose(MC) and grape seed extract(GSE) were prepared by casting their aqueous solution at 80℃ and drying at 23℃ for 48 hrs. Effect of grape seed extract(GSE) on the barrier permeabilities and the thermomechanical property of methylcellulose(MC) film was studied. The barrier permeabilities and the thermomechanical property of MC film containing various contents of GSE were evaluated in terms of water vapor, oxygen permeabilities, and dynamic mechanical analysis(DMA). The rate of water vapor permeability of MC film decreased with GSE contnets in the MC films. Also, the rate of oxygen permeability also decreased with GSE contents indicating higher oxygen barrier property of MC film. The results showed that GSE had a good miscibility with MC and acted as a plasticizer for MC film resuling in lowering the glass transition temperature of the film.

공동주택에 있어서 하자발생현황 및 보수책임기간에 관한 연구

유진호,김준환,김용수 중앙대학교 건설산업기술연구소 2001 건설산업기술연구소 논문집 Vol.2 No.-

The purpose of this study is to suggest a practical guarantee period in apartment buildings. The study has been performed by survey and interview for apartment buildings and managers in Seoul, Kyunggi and Chonnam provinces. The results of this study are as follows: 1. Practical guarantee periods of plastering, waterproofing, and tiling work are 2.3∼3.2, 3.5∼4.3, and 3∼4 years. 2. Rational guarantee periods of joiner's work, factory work, and paper hanging work are 2.7∼3.4, 2∼3, and 2.1∼2.6 years. 3. Rational guarantee periods of lighting work, water supply work, and water disposal work are 1.8∼2.4, 1.8∼3.4, and 2.6∼3.8 years. 4. Rational guarantee periods of sanitary fixture work, and kitchen facility work are 2.7∼2.9, and 1.8∼2.4 years.