The Primary Patency and Fracture Rates of Self-Expandable Nitinol Stents Placed in the Popliteal Arteries, Especially in the P2 and P3 Segments, in Korean Patients

장일수,지현근,박상우,윤익진,황재준,이송암,김준석,장성환,정홍근 대한영상의학회 2011 Korean Journal of Radiology Vol.12 No.2

Objective: We wanted to evaluate the status of self-expandable nitinol stents implanted in the P2 and P3 segments of the popliteal artery in Korean patients. Materials and Methods: We retrospectively analyzed 189 consecutive patients who underwent endovascular treatment for stenoocclusive lesions in the femoropopliteal artery from July 2003 to March 2009, and 18 patients who underwent stent placement in popliteal arterial P2 and P3 segments were fi nally enrolled. Lesion patency was evaluated by ultrasound or CT angiography, and stent fracture was assessed by plain X-rays at 1, 3, 6 and 12 months and annually thereafter. Results: At the 1-month follow-up, stent fracture (Type 2) was seen in one limb (up to P3, 1 of 18, 6%) and it was identifi ed in seven limbs at the 3-month follow-up (Type 2, Type 3, Type 4) (n = 1: up to P2; n = 6: P3). At the 6-month follow-up, one more fracture (Type 1) (up to P3) was noted. At the 1-year follow-up, there were no additional stent fractures. Just four limbs (up to P2) at the 2-year follow-up did not have stent fracture. The primary patency was 94%, 61% and 44% at 1, 3 and 6 months, respectively, and the group with stent implantation up to P3 had a higher fracture rate than that of the group that underwent stenting up to P2 (p < 0.05). Conclusion: We suggest that stent placement up to the popliteal arterial P3 segment and over P2 in an Asian population can worsen the stent patency owing to stent fracture. It may be necessary to develop a stent design and structure for the Asian population that can resist the bending force in the knee joint.

고주파 열치료시 두 개의 전극을 이용한 동시 소작의 유용성에 관한 실험적 연구

장일수,임현철,고병희,조온구,서흥석,김용수,김영선,허정남 대한영상의학회 2003 대한영상의학회지 Vol.48 No.2

The Effi cacy of the Coaxial Technique Using a 6-Fr Introducer Sheath in Stent Placement for Treating the Obstructions Proximal to the Descending Colon

장일수,박상우,황대용,성무경,조희경,윤소영,조요한,최원혁 대한영상의학회 2011 Korean Journal of Radiology Vol.12 No.1

Objective: We wanted to evaluate the effi cacy of stent placement using the coaxial technique with a stiff, long introducer sheath in patients with technical failure using an angiographic catheter for the obstructions proximal to the descending colon. Materials and Methods: Self-expandable metallic stent placement was attempted under fluoroscopy-guidance in 77 consecutive patients who had malignant colorectal obstruction. Stent placement was performed using an angiographic catheter and a guide wire. If the angiographic catheter could not be advanced over the guide wire into the obstructive lesions proximal to the descending colon, then a 6-Fr introducer sheath was used. The technical success rate, the clinical success rate and the complications were analyzed. Results: Successful stent placement was achieved in 75 of 77 patients (97%). The angiographic catheter failed to advance into the obstructive lesions of 11 patients (M:F = 7:4; mean age, 65.5 years) whose lesions were at the level of the splenic fl exure or transverse colon. Therefore, the coaxial technique was implemented in all these 11 patients using a 6-Fr stiff introducer sheath and then the stent placement was successful. There were no complications related to the use of a stiff introducer sheath. Clinical success, which was defined as relief of clinical obstructive bowel symptoms, was obtained within 24 hours in all of patients. Conclusion: The coaxial technique using a stiff introducer sheath can increase the technical success of fl uoroscopy-guided, self-expandable metallic stent placement in patients with colonic obstruction proximal to the descending colon. Objective: We wanted to evaluate the effi cacy of stent placement using the coaxial technique with a stiff, long introducer sheath in patients with technical failure using an angiographic catheter for the obstructions proximal to the descending colon. Materials and Methods: Self-expandable metallic stent placement was attempted under fluoroscopy-guidance in 77 consecutive patients who had malignant colorectal obstruction. Stent placement was performed using an angiographic catheter and a guide wire. If the angiographic catheter could not be advanced over the guide wire into the obstructive lesions proximal to the descending colon, then a 6-Fr introducer sheath was used. The technical success rate, the clinical success rate and the complications were analyzed. Results: Successful stent placement was achieved in 75 of 77 patients (97%). The angiographic catheter failed to advance into the obstructive lesions of 11 patients (M:F = 7:4; mean age, 65.5 years) whose lesions were at the level of the splenic fl exure or transverse colon. Therefore, the coaxial technique was implemented in all these 11 patients using a 6-Fr stiff introducer sheath and then the stent placement was successful. There were no complications related to the use of a stiff introducer sheath. Clinical success, which was defined as relief of clinical obstructive bowel symptoms, was obtained within 24 hours in all of patients. Conclusion: The coaxial technique using a stiff introducer sheath can increase the technical success of fl uoroscopy-guided, self-expandable metallic stent placement in patients with colonic obstruction proximal to the descending colon.

Efficacy and Safety of Balloon-Occluded Retrograde Transvenous Obliteration with Sodium Tetradecyl Sulfate Liquid Sclerotherapy

장일수,박상우,권소영,최원혁,천영국,심찬섭,이태윤,김정한 대한영상의학회 2016 Korean Journal of Radiology Vol.17 No.2

Objective: To evaluate the efficacy and safety of balloon-occluded retrograde transvenous obliteration (BRTO) with sodium tetradecyl sulfate (STS) liquid sclerotherapy of gastric varices. Materials and Methods: Between February 2012 and August 2014, STS liquid sclerotherapy was performed in 17 consecutive patients (male:female = 8:9; mean age 58.6 years, range 44–86 years) with gastric varices. Retrograde venography was performed after occlusion of the gastrorenal shunt using a balloon catheter and embolization of collateral draining veins using coils or gelfoam pledgets, to evaluate the anatomy of the gastric varices. We prepared 2% liquid STS by mixing 3% STS and contrast media in a ratio of 2:1. A 2% STS solution was injected into the gastric varices until minimal filling of the afferent portal vein branch was observed (mean 19.9 mL, range 6–33 mL). Patients were followed up using computed tomography (CT) or endoscopy. Results: Technical success was achieved in 16 of 17 patients (94.1%). The procedure failed in one patient because the shunt could not be occluded due to the large diameter of gastrorenal shunt. Complete obliteration of gastric varices was observed in 15 of 16 patients (93.8%) with follow-up CT or endoscopy. There was no rebleeding after the procedure. There was no procedure-related mortality. Conclusion: BRTO using STS liquid can be a safe and useful treatment option in patients with gastric varices.

RFID GEN2 태크 표준의 VHDL 설계

장일수,양훈기 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.12

협조적 게임에 의한 송전요금체계: 국내 전력시장을 사례로

장일수 재단법인 에너지경제연구원 2015 에너지경제연구 Vol.14 No.3

This article modeles Korean power transmission system, and calculates transmission fees by using Aumann-Shapley method and compares them with the current transmission fee. To analyze the effect of a new transmission line on the whole transmission fees, Miryang high-voltage transmission line and other two related lines are added in the model. The results show that the Aumann-Shapley method does well in providing rational economic signals in making transmission fee policies, and also provides good explanations of the impact of added transmission lines on the transmission fees. 이 논문에서는 국내 전력산업에서의 전력계통을 모형화하고 협조적 게임의 해인 Aumann-Shapley 밸류로 발전 측과 부하 측의 송전요금을 산정하여 현재 시행하고 있는 국내 송전이용요금체계와 비교・분석하였다. 또한 최근 이슈화되고 있는 송전선로 건설이 송전요금에 주는 영향을 관찰하기 위하여 밀양송전탑 및 관련된 기타 송전선로를 추가한 후 송전요금의 변화도 관찰하였다. 이로써 협조적 게임의 해인 Aumann-Shapley 밸류는 발전 및 부하 측 송전요금의 책정에서 경제적 신호를 잘 제공하고 있다는 것을 보여 주었다. 또한 협조적 게임을 사용하면 송전선로의 추가 건설이 각 지역의 송전요금에 어떠한 영향을 주는지에 대해서도 합리적인 설명이 가능하다는 것을 보여주었다.

RFID Classl Generation2 태그의 FPGA 구현을 위한 설계 연구

장일수(Jang Il soo),양훈기(Yang Hoon gi) 한국통신학회 2007 한국통신학회 학술대회논문집 Vol.2007 No.7

UHF 대역 RFID 태그 디지털 프로세서의 설계 연구 및 시뮬레이션

장일수(Jang Il Su),양훈기(Yang Hoon Kee) 한국통신학회 2006 한국통신학회 학술대회논문집 Vol.2006 No.11

RFID GEN2 태그 표준의 VHDL 설계

장일수(Il Su Jang),양훈기(Hoon Gee Yang) 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.12A

본 논문에서는 UHF 대역 RFID 수동형 태그의 디지털 회로부 구현을 위한 VHDL 설계과정을 보인다. 태그의 동작은 EPCglobal Class1 Gen2 표준을 지원하며 합성과 구현과정을 거친 타이밍 시뮬레이션 결과를 통해 검증하였다. 수 미터의 인식거리로 인해 Frame-Slotted Aloha를 사용하는 환경에서, 단위시간당 태그 인식률을 향상시키기 위해서는 리더 명령에 대한 빠른 처리와 응답을 할 수 있는 디지털 회로 설계가 필요하다. 본 설계는 Pipeline 처리 구조를 기반으로 직렬 입력 신호에 대한 응답지연의 최소화를 목표로 하였다. 또한, 효율적인 다중 접속 명령들의 처리와 태그의 데이터 전송 속도의 오차를 낮추기 위해 리더의 Preamble과 PIE 디코딩을 위한 샘플링 과정을 제안하였다. FPGA 검증을 위한 Place & Route 후 다중 태그 상황을 감안한 테스트 벤치 시뮬레이션 결과, 표준상의 최대 송수신 데이터 전송 속도에서 디코딩 및 인코딩 을 위한 최소 요구 시간 보다 빠른 처리 결과를 확인 할 수 있었다. This paper presents the VHDL implementation procedure of the passive RFID tag operating in Ultra High Frequency. The operation of the tag compatible with the EPCglobal Class1 Generation2(GEN2) protocol is verified by timing simulation after synthesis and implementation. Due to the reading range with relatively large distance, a passive tag needs digital processor which facilitates faster decoding, encoding and state transition for enhancement of an interrogation rate. In order to satisfy linking time, the pipe-line structure is used, which can minimize latency to serial input data stream. We also propose the sampling strategy to decode the Preamble, the Frame-sync and PIE symbols in reader commands. The simulation results with the fastest data rate and multi tags environment scenario show that the VHDL implemented tag performs faster operation than GEN2 proposed.

ADS를 이용한 UWB TR과 BPM 변조의 AWGN & 다중경로 채널 테이터 변복조 시뮬레이션

장일수(Jang Ilsu),최호선(Choi Hoseon),우선걸(Woo Sunkeol),양훈기(Yang Hoongee) 한국통신학회 2005 한국통신학회 학술대회논문집 Vol.2005 No.6