여성 복압성요실금 치료에서 Tension-free Vaginal Tape 술식의 5년 추적 결과

두진경 울산대학교 대학원 2005 국내석사

여성 복압성요실금 환자에서 tension-free vaginal tape(TVT)술식 후 5년이상의 장기 추적결과를 알아보고자 하였다.1999년 3월부터 2000년 6월까지 TVT술식을 시행한 155명의 환자 중 5susd 이상 추적 관찰된 138명 (52.4±9.3세)을 대상으로 하였다.수술 전후에 병력 청취,신체검사,패드검사,요속검사 및 수술전 요역동학적 검사와 수술 후 설문지를 시행하였다.환자의 평균 분만력은 3.3±1.6회,체질량지수는 24.1±2.7kg/m²이었으며,과거력 상 8명 (5.8%)dms 요실금 수술을 17명(12.3%)은 자궁 절제수루을 시행 받았다, 수술 전 절박성요실금은 27명 (19.6%),요절박은 32명(23.2%)에서 있었고,요실금 정도는 grade I,67명(48.6%),grade II 66명 (47.8%) .grade III 5(3.6%)명이었고 술 후 평균 추적기간은 67.2±4.61개월 이었다.요실금유발검사에서 요실금이 없으면서 복압상승시 불수의적인 요실금이 없는 상태를 완치로 정의하였다.수술 후 1년째 치료성공률은 완치가 90.4%(122/135).호전이 7.4%(10/135)였으며 5년째 치료성공률은 완치가 76.8%(106/138).호전이 18.1%(25/138)였다. 만족도(매우만족 +만족)는 86.9%(120/138)였다.최대요속은 술 전 26.9±9.5ml/s에서 술 후 1달에 20.4±8.4ml/s로 유의한 감소가 있었으나 술 후 5년에 28.3±37.3ml/s로 술 전과 의미있는 변화가 없었고 잔뇨는 술 전 15.3±26.4ml에서 술 후 1달에 24.1±32.7ml,술 후 5년에 29.3±46.5ml으로 계속 유의하게 증가하였다.(P<0.05).술 후 합병증은 방광천공 6명 (4.3%),TVT tape 절제 및 완화가 11명 (8.0%),배뇨장애로 인한 자가도뇨가 1명(0.7%)이었고,16명 (15.4%)이 술 후 새로이 요절박을 호소하였다, 요절박을 호소하던 32명 줄 14명 (43.8%)에서,절박성 요실금을 호소하던 27명 중 13명 (48.1%)에서 증상의 호전이 있었다.단변량과 다변량 분석시 술 전 인자 중 완치에 관련된 유의한 인자는 없었으며 요절박이 만족도에 의한 인자였다.(p=0.017).체질량지수를 25kg/m²미만과 이상으로 나누었을 때 두 군간 완치율은 각각 68.3%,83.3%(p=0.044),VLPP를 60cmH₂O미만과 이상으로 나누었을 때 각각 51.6%,82.8%(p=0.003),요실금 정도로 나누었을 때 각각 40.0%,69.7%,86.6%로 (p=0.012) 유의한 차이가 있었다.그 외 성공률에 관련된 유의한 인자는 없었다.TVT술식은 높은 장기 치료 성공률과 만족도를 보였으며,안전한 수술법으로 생각된다. 그러나 낮은 VLPP,높은 체질량지수와 grade III 요실금은 명확한 위험인자는 아니었지만 TVT 수술 후 치료 완치율을 낮출 수 있을 것으로 생각된다.

(An) effective suppression methodology of the simultaneous switching noise in multi-layer high performance printed circuit boards

두진경 Graduate School, Yonsei University 2007 국내석사

본 논문에서는 기존의 Electromagnetic Bandgap (EBG) 구조의 필터링 현상을 바탕으로 하여, Simultaneous Switching Noise (SSN)를 보다 효과적으로 억압시킬 수 있는 방법에 대해 연구하였다. 기존의 EBG 구조의 주기적인 패턴과는 달리, 소수의 패턴만을 전원층 (power plane)에 적용시킴으로써 유사한 SSN 억압 특성을 얻을 수 있는데, 이는 패턴의 필터링 효과 때문이다. EBG 구조의 SSN 억압 현상을 설명하기 위해 등가 회로가 사용되어 왔으나 이는 집중 소자들 (lumped elements)로만 이루어져 있기 때문에 정확성에 한계가 있다. 따라서 본 논문에서는 분산 소자 (distributed elements)를 일부 적용시킴으로써 EBG 구조의 억압 특성을 보다 정확히 표현하였고, 이를 바탕으로 하여 패턴의 모양을 변화시킴으로써 SSN 억압 특성을 향상시켰다. 패턴의 전체 크기를 줄여 고주파 대역으로 억압 영역을 확장하였으며, 패턴 사이 연결부의 수를 줄이고 길이를 늘림으로써 저주파 대역으로 억압 영역을 또한 확장하였다. 그 결과 0.8 GHz부터 7.5 GHz까지의 대역에서 -25 dB 이하의 억압 특성을 얻었다. 그리고 이와 같이 향상된 특성의 패턴을 4층 기판에 실제로 적용시킨 결과, 넓은 대역에서 잡음의 전달이 크게 줄어드는 것을 확인하였다. In this thesis, filtering effects of the conventional electromagnetic bandgap (EBG) structures are investigated to propose the enhanced equivalent circuit which describes the suppression characteristics more exactly. To reduce the simultaneous switching noise (SSN) effectively without signal integrity (SI) problems, an effective suppression methodology was reported. The reported methodology shows similar suppression characteristics with the conventional EBG structures due to filtering effects. But the conventional equivalent circuit is not enough to explain the suppression characteristics of the conventional EBG structures exactly. Therefore an enhanced equivalent circuit is required to understand the filtering effects.And, based on the achieved equivalent circuit, suppression of the SSN is improved by modifying the suppression patterns. To increase the inductance of bridge, the number of bridges for each pattern is reduced to the minimum, and the meander-shaped bridges are used. As the result, good suppression of the SSN is achieved from 0.8 GHz to 7.5 GHz below -25dB. And by applying the improved patterns to 4-layer test boards, good suppression of noise coupling is achieved below -23 dB. Therefore the improved suppression methodology is enough to be applied to the real PCBs without the additional SI problems.

Analysis of coupling effects from IEMI to multilayered PCBs in metallic enclosures

두진경 Graduate School, Yonsei University 2015 국내박사

The intentional electromagnetic interference (IEMI) penetrates into electric devices and makes malfunctions or destructions of them. To protect the electric devices against IEMI, metallic enclosures have been utilized, and the shielding effectiveness of the metallic enclosure has been studied actively. Even though many literatures report simulation and measurement techniques to probe the electromagnetic fields inside the metallic enclosure, it is not enough to predict coupling effects to a target PCB in the metallic enclosure. Moreover, the multilayered structure of the PCB should be considered because those structures have their own resonant characteristics which affect to coupling phenomena. Hence, in this dissertation, radiated coupling effects from the IEMI to a multilayered PCB in the metallic enclosure are studied. Based on the coupling mechanism in free-space, the coupling effects in the metallic enclosure are revealed, and a PCB and aperture placement guide is proposed for further reduction of the radiated coupling effects. The established coupling mechanism in the metallic enclosure is also applied to analyze coupling phenomena in several metallic waveguides which include multilayered PCBs and apertures inside. Calculated results support the coupling mechanism reasonably. The IEMI is handled as an incident plane wave, and it is assumed that the electric field intensity around the target PCB is 1 V/m. In free-space, the IEMI excites resonant modes of a multilayered PCB, and the resonant modes are differently generated in accordance with the PCB orientations. The effects of PCB resonances are appeared as coupling peaks in the frequency domain, and the maximum induced voltage is -35 dBV when a target trace includes a via-hole connecting different signal layers. The smallest coupling level is resulted when a normal vector of the PCB surface, a field polarization vector of the incident plane wave, and a wave vector indicating a direction of the propagating waves are perpendicular to each other. The smallest voltage level induced to traces is -60 dBV, regardless of the via-hole existence. Simulated and measured results considerably support the established coupling mechanism. In the metallic enclosure including a multilayered PCB, as well as an aperture, the coupling effects are also influenced from resonant modes of the entire structure, resulting peaks in the frequency domain. Below the fundamental frequency of the metallic enclosure, coupling peaks are dominantly generated by the PCB resonances, which are predictable. Whereas, above the fundamental frequency, peak frequencies are densely appeared thus they are mostly unpredictable. The maximum peak level is around -35 dBV, but it can be suppressed to -47 dBV by adjusting the placement of PCB and aperture. To reduce the coupling effects in the metallic enclosure, the placement of PCB and aperture should be handled properly, thus a useful guide is proposed in this work. The established coupling mechanism in the metallic enclosure is also utilized to analyze missile-type structures which are simplified to rectangular waveguides. The coupling effects from the IEMI to multilayered PCBs in metallic waveguide structures are investigated using the full-wave method, as well as the EMT method. For analysis using the EMT method, the modified BLT equation is proposed, and full-wave analysis data for partial structures are combined with the modified BLT equation to handle a multi-scale problem. Constructing of a topological network for waveguide structures is demonstrated considering propagating modes of the waveguide. The calculated results by the full-wave analysis, as well as the modified BLT equation, considerably support the coupling mechanism in the metallic enclosure, and especially, PCB resonant modes are obviously appeared below the fundamental frequency of the metallic enclosure. Considering the coupling mechanism investigated in this dissertation, the radiated coupling effects from the IEMI to a multilayered PCB in the metallic enclosure can be suppressed further by placing the PCB and aperture properly. It will be also helpful to predict the coupling phenomena in other metallic structures including multilayered PCBs, effectively.