A Study on the Correlation of Left Atrial Volume Change according to Left Ventricular Contraction in Atrial Fibrillation

Sung Kwan Kim,Hee Chang Chae,Choong Beom Seo,Eun Hee Seo,Chang Min Dae,Tae Eun Kim 대한CT영상기술학회 2022 대한CT영상기술학회지 Vol.24 No.1

The purpose of this study was to increase accuracy and success rate of radiofrequency catheter ablation by analysis of left atrial volume change relative to left ventricular volume change and left atrial diameter change relative to left atrial volume change. 20 patients with normal heart rhythm were set as the control group, and 20 patients with diagnosed atrial fibrillation were set as the experimental group. The cardiac cycle was divided into 10 stages ranging from 0% to 90%, and left ventricular volume, left atrial volume, left atrial diameter, pulmonary vein diameter were measured for each group. the correlation between the left ventricular volume and the left atrial volume was analyzed, and the correlation between the left atrial volume and left atrial diameter was analyzed. The diameter of the pulmonary veins was measured. As a result of analyzing the correlation between left ventricular volume and left atrial volume through Spearman correlation, the control group showed a negative correlation.(P<0.001) The experimental group were not correlated.(P=0.075) As a result of analyzing the correlation between the left atrial volume and the left atrial diameter, both groups showed a positive correlation.(P<0.001) As a result of analyzing the diameter of the pulmonary vein by Wilcoxon signed-rank test, both groups showed a significant difference in the maximum diameter and the minimum diameter.(P<0.001) Because the volume and diameter of the left atrium in patients with atrial fibrillation change irregularly, the radiologist check all cardiac cycle and reconstruct to increase the accuracy and success rate of radiofrequency catheter ablation.

Assessment of Aortic Annulus Dimensions for Patients with Hypertrophic Cardiomyopathy in Pre-TAVI Planning CT

송민철(Min-Cheol Song),김태은(Tae-Eun Kim),채희창(Hee-Chang Chae),서충범(Choong-Beom Seo),서은희(Eun-Hee Seo),대창민(Chang-Min Dae) 대한CT영상기술학회 2023 대한CT영상기술학회지 Vol.25 No.2

본 연구는 비후성 심근증 환자의 심장 주기에 따른 대동맥판륜의 형태학적 크기 변화를 측정하여 TAVI planning 3차원 영상처리시 대동맥판륜의 크기 측정 오류와 합병증을 최소화하고자 연구를 진행하였다. 2021년 4월부터 2022년 6월까지 본원을 내원하여 심전도 동조화 기법 TAVI planning CT 검사를 진행한 환자 중 심실중격 두께가 정상인 환자를 대조군 41명(78.92 ± 12.6세, 남성 44%), 비후성 심근증 환자를 실험군 31명(74.92 ± 10.8세, 남성 61%)으로 설정하였다. 심장 주기의 10% 간격으로 영상재구성하여 대동맥판륜의 면적, 둘레, 유효 직경, 면적 기반 직경, 둘레 기반 직경을 측정하여 비교 분석 하였다. 분석 결과, 심장 주기 동안 대동맥판륜의 면적, 둘레, 유효 직경, 면적 기반 직경, 둘레 기반 직경의 상대적인 변화는 각각 27.3%, 10.4%, 11.9% 12.6% 11.1%로 유의한 크기 변화를 나타냈다.(P<0.001) 대조군은 전체 심장 주기 중 수축기에서 대동맥판륜 각 측정인자의 최대값이 나타났으며, 실험군은 전체 심장 주기에서 측정 인자의 최대값이 불규칙적으로 나타났다. 또한 두 그룹 간 심장 주기 동안 대동맥판륜 측정 인자의 최대값 빈도 분포 분석 결과는 유의한 차이를 나타냈다.(P<0.05) TAVI 3차원 영상처리에 있어 비후성 심근증 환자의 경우 전체 심장 주기를 확인하여 대동맥판륜 크기가 가장 큰 심장 주기에서 측정하는 것이 정확한 크기의 인공판막 선택과 추후 합병증을 최소화하는데 큰 기여를 할 것으로 사료된다. The purpose of this study was to minimize the undersizing of aortic annulus size and reduce complications by analysis the size change of aortic annulus during the cardiac cycle in patients with hypertrophic cardiomyopathy. Patients were prospectively underwent an ECG-gated TAVI Planning CT. Retrospective study was conducted 41 normal group (78.92 ± 12.6 years; 44% males) and 31 hypertrophic cardiomyopathy group (74.92 ± 10.8 years; 61% males). The annulus plane was identified on reconstructions at 10% intervals of the cardiac cycle. Based on semi-automatically defined Aortic annulus, area, perimeter, effective diameter, area-derived diameter, perimeter-derived diameter were measured. The area, perimeter, effective diameter, area-derived diameter and perimeterderived diameter were significantly changes during the cardiac cycle with a relative change of 27.3%, 10.4%, 11.9%, 12.6% and 11.1% respectively. (all p < 0.001) During the cardiac cycles of groups normal and Hypertrophic myopathy, aortic annulus showed different dynamic changes. Different group showed a significant difference in the maximum values distribution plot. (p < 0.05) In patients with hypertrophic cardiomyopathy, reconstructing the entire cardiac cycle and selecting the largest annulus to TAVI planning is considered to contribute greatly to the accurate selection of the size of prosthesis in the procedure and minimizing TAVI complications.

췌장염에 의한 가성낭종내에 생긴 가성동맥류 : 1례 보고

오연희,이채경,김승현,이성우,양창현,이정호,이영현 동국대학교 경주대학 1996 東國論集 Vol.15 No.-

만성 췌장염의 합병증으로 생긴 가성동맥류는 드문질환으로, 반복적으로 다량의 출혈을 일으킬 수 있으며, 치료를 하지 않을 경우 사망율이 높기 때문에, 조기 진단과 치료가 필수적이다. 저자들은 38세 남자 환자에서 췌장염의 합병증으로 생긴 가성낭종내에서 발생한 가성동맥류 1예를 경험하였기에 보고하는 바이다. 가성 동맥류의 색혈류도플러상 낭종내에 양방향 흐름의 와류를 볼 수 있었다. Pancreatic Pseudoaneurysm within Pseudocyst from Pancreatitis: 1 Case Department of Diagnostic Radiology and Internal Medicine, College of Medicine,DongGuk University Yeon Hee OH M.D., Chae Kyeong Lee M.D., Seoung Hyeon Kim M.D., Sung Woo Lee M.D., Chang Heon Yang M.D., Jung Ho Lee M.D., Young Hyun Lee M.D. Pseudoaneurysm from pancreatitis is uncommon, but it can cause recurrent and massive hemorrhage. Because of high morbidity and mortality, early detection and treatment of the pseudoaneurysm is needed. We report a case of pseudoaneurysm within pseudocyst from pancreatitis. Color-flow Doppler sonography shows bidirectional flow and turbulent arterial flow, within anechoic mass.

제왕절개술을 위한 경막외 마취시 술전 투여 수액이 신생아 혈당치에 미치는 영향

이혜원,김선희,신정순,장성호,임혜자,채병국 대한마취과학회 1993 Korean Journal of Anesthesiology Vol.26 No.4

It is common for patient undergoing cesarean section under epidural anesthesia to have lower blood pressure because of not only supine hypotension syndrome but vasodilation due to sympathetic blockade. So it is necessary to give large volume of fluid before perfarming epidural anesthesia to prevent hypotension. When we use the dextrose containing fluid for that purpose, newborn baby could have a high blood glucose at delivery and low blood glucose level due to high insulin level after birth. The authors examined the blood glucose level at delivery and two hours after birth following use of 5% dextrose in lactated Ringers solution(HD group, n=24) or lactated Ringers solution (HS group, n=24) for prevention of hypotension during epidural anesthesia for cesarean section. The results were as follows; 1) The total amount of fluid was 789.6±264.2 ml in HD group and 741.1±253.5 ml in HS group. 2) The glucose level of mother at delivery was 300.9±76.3 mg/dl in HD group and 98.7±24.6 mg/dl in HS group and there wastistical significance(p$lt;0.01). 3) In HD group, the glucose level of newborn baby was 212.2±57.2 mg/dl at delivery and 465.±20.3 mg/dl at 2 hours after birth. The change of amount during 2 hours after birth was highly related to the glucose level at birth. Higher level of glucose at birth, larger amount of change during 2 hours after birth. 4) In HS group, the glucose level of newborn baby was 66.8±10.2 mg/dl at birth and 67.0±12.1 mg/dl at 2 hours after birth. There was no significant change.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

壓縮用 圓錐 코일 스프링의 컴퓨터 利用設計

蔡熙昌,鄭寅聖 全北大學校 1990 論文集 Vol.32 No.-

CAD of the conical springs under compressive load was studied in the personal computer. Unlike cylindrical spring, the behavior of conical coil spring is very complex and difficult to be calculated. Under the critical load, the spring has linear characteristics. When the load is above the critical value, the relation between load and deformation is no more linear. Even though the stress of spring material is below the proportional limit, non-linear phenomena appears due to the reduction of deformable portion of the spring. Design equations of the conical spring and design constraints were searched. Non-linear least square method was used to get the design parameters for the given design conditions. This method is more stable and useful than Newton method in the field of mechanical design.

삼각형기반 형상모델러를 이용한 STL의 검증

채희창,김동우 한국공작기계학회 1997 한국생산제조학회지 Vol.6 No.1

The verification of the STL file is essential to build the confident parts using a RP machine, because the STL file obtained from the CAD software has many errors - the orientation of triangle does not coincide with adjacent triangles or some triangles are omitted, overlpped and so forth. Especially, the STL file translated from the surface model has more errors than those translated from the solid model. In this study, all possible errors were classified with the most general form and the causes of errors were analyzed to verify and correct errors. Using the triangle based non-manifold geometric modeling, these errors were corrected. Especially, this study took the notice of the problem about the intersected triangles and non-manifold properties overlooked in the previous studies. But this study has a penalty on computing time of O(n^2)

점 데이터를 이용한 3차원 형상의 구현을 위한 소프트웨어 개발

채희창 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.1

Reverse engineering is an emerging technology to obtain CAD models from existing physical parts in the case that CAD models are not available or parts are changed and modified so that new CAD models for final parts are necessary. Reverse engineering helps designers to quickly generate compute interpretable data from existing physical objects. So it applying for field of Rapid Prototyping NC Processing CAE, Inspection and so on. The objective of this study is to develop the software that deals with unorganized point data and quickly obtains CAD model. In this paper, several models such as human's bone, car , are experimented by the proposed methods.

대형물의 RP 작업을 위한 절단 알고리즘의 개발

채희창,강희용,유상훈,이승현,문홍렬 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.2

Nowadays, as the development period of new products becomes shorter and consumer's requirement is more various, the importance of Rapid Prototyping Technology has been rapidly increased. Rapid Prototyping makes prototypes or functional parts directly using the 3D CAD data. But RP machines can make protypes in limit size. For making large size prototype, we slice solid, which is made of STL file, and then glue sliced solid. And if contact area of part is small, union solid will be easily destroyed for going down of adhesion. So we need to expand contact area, I suggest making a section into stair shape. This paper is concerned with slicing solid on STL file and improving on adhesion.

고속적층조형법에서 성형 정밀도와 Support Sturcture를 고려한 최적 적층방향의 결정

채희창 全北大學校 1996 論文集 Vol.42 No.-

Rapid Prototyping(RP) is the technique which is used to make prototypes or functional parts directly using the 3-D solid data. Before building the prototype, several processes such as transfering 3D data from CAD system(STL), determination of build-direction, adding support sutructure and slicing are required. Among the above processes, determination of build-direction is the target of this study. The build-direction is determined by many factors according to the objective of the user, like part accuracy, number of support structure, build time, amount of trapped volume, etc. But it is not easy to determine the build-direction because there are many factors and some factors have dependent properties with one another. So, in this study the part accuracy and the number of support structures are considered as the main factor to determine the optimal build-direction. To determine the optimal build-direction for increasing part accuracy, sum of projected area which caused stairstepping effect was considered. The less the projected area is the better part accuracy os. About the optimal build-direction to minimize the amount of support structure, similar projected area of facets that require support structures was considered. Finally total object function for both of part accuracy and the amount of support structures was derived. It is composed of two non-dimensional object functions and two weighting factors. First function is the ratio of projected area and total facet area. The second function is the ratio of projected area of facets that require support structures and total facet area.