• Journal of Chest Surgery
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• 제24권7호
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• pp.693-700
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• 1991

A rare case of the association of distal aortopulmonary septal defect, aortic origin of the right pulmonary artery, intact ventricular septum, patent ductus arteriosus and interrupted aortic isthmus in a 40-day-old infant is reported. The infant was suffered from two operations with an interval of nine days. At the first operation a 10mm polytetrafluoroethylene prosthesis was inserted instead of the interrupted aortic isthmus and ductus was ligated via the left posterolateral thoracotomy. But the patient could not be weaned from the respirator because of large amount of left-to-right shunt. So the total correction was subsequently performed after an interval of nine days. At the second operation, tunneling of the right pulmonary artery to the main pulmonary artery through the aortopulmonary septal defect was performed using the Dacron patch via a longitudinal transaortic approach and a separate autologous pericardial patch was applied to the longitudinally incised margins of the anterior wall of the ascending aorta. The second postoperative course was relatively uneventful except some respiratory distress and nutritional problems. Now he is at 6 months of age and thrives well without any symptom. Because the success of the surgical repair of this complex anomalies depends upon the accurate diagnosis and meticulous design of each step of procedure prior to operation these problems are also discussed.

• 대한치과기공학회지
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• 제38권3호
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• pp.119-125
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• 2016

Purpose: The purpose of this study is to evaluate the marginal gap of all-ceramic crowns fabricated by CEREC$^{(R)}$ in-office CAD/CAM system. Methods: The mandibular first molar was selected as the abutment for the experiments. Thirty working models were prepared. VITA Mark II(VM) and VITA Enamic(VE), LAVA Ultimate(LU) blocks were milled using CEREC MCXL with CEREC 3D system to construct 10 crowns for each groups. To measure marginal gap, milled restorations were examined under digital microscope with scale under 160x magnifications. The results were statistically analyzed using the one-way ANOVA and Tukey's HSD test(${\alpha}=0.05$). Results: There was no significant difference in the marginal gap regarding to ceramic materials(p>0.05). Conclusion: Single crowns fabricated using CEREC in-office CAD/CAM system provided clinically acceptable marginal gap. This confirmed that the type of ceramic material used does not determine the precision of fit of a prosthesis.

• 대한의용생체공학회:의공학회지
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• 제18권4호
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• pp.413-420
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• 1997

In this paper, we analyzed the contraction patterns of active elbow muscles during isometric, concentric and eccentric contraction. The analysis parameters consist of frequency domain parameters (mean frequency, median frequency, peak frequency, peak power, skewness, kurtosis) and time domain paraseters (zero crossing, positive maxima, integrated EMG). The results of this study were as follows; The BR/BB of isometric contraction appeared to be Venter as the elbow joint was more extended. The BR /BB during concentric and eccentric contraction tended to increase with more extension of the elbow joint angle, but there was no significant difference between concentric and eccentric contraction. Further, the EMG power spectrum due to the type of contraction were different betwen eccentric and concentric contraction. According to the results, it was found that the activation pattern in elbow flexor muscles was different during three different muscle contraction pattern. Therefore, elbow flexor muscles should not be considered a single functioning unit. Especially, at the time domain analysis, IEMG is a dominant parameter for analysis of activation patterns, and the skewness kurtosis can be useful parameters in functional recognition for prosthesis control purpose.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.891-894
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• 2005

This paper describes a human finger model driven by shape memory alloy(SMA) wires. The finger model has three joints that are similar to human finger. Each joint is actuated with two wires in the antagonistic manner and six wires are used to actuate three finger joint. In order to obtain the desirable finger motion, the diameters of the SMA wires are designed with different diameters by considering the required actuating force and response time. The rotary sensors are used to measure the angle positions of the joints and PWM control using PID algorithm is used to achieve desired angle positions of the finger joints. After estimating the control performance of each finger joint for the desired angle position, the antagonistic motion control of the finger model is experimentally evaluated.

• 대한방사선기술학회지:방사선기술과학
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• 제44권3호
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• pp.189-194
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• 2021

This study was conducted to reduce the exposure dose to the breast and adjacent organs as the number of Mammography increased. Therefore, it has been designed a shield in lead, bismuth + tungsten, and bismuth that does not require to be equipped by the patient, in which each type of shield was compared and analyzed of radiation exposure dose to breast, thyroid, and eye. Using a mammography machine, optically stimulated luminescent dosimeter(OSLD) was inserted to bilateral breast, thyroid, and eye of a dosimetry phantom to measure dose radiated onto the phantom. Shielding device was made in different thickness of 2mm, 3mm, and 5mm and dose evaluation was performed by measuring the dose while using lead, bismuth, and bismuth + tungsten prosthesis. When each shields combined with shielding device, were compared of dose, all showed similar does reduction in the dose to breast, thyroid, and eye in both cranialcaudal and mediolateraloblique view. Based on the current study, bismuth and bismuth + tungsten can replace conventional lead shield and it is anticipated to safely and conveniently reduce radiation exposure to breast, thyroid, and eye with the shield that does not require to be equipped.

• 대한후두음성언어의학회지
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• 제14권2호
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• pp.117-122
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• 2003

Background and Objectives : $VoCoM^{\circledR}$ is a commercialized set composed of prefabricated hydroxylapatite implants and shims of various sizes which are specially designed for the type I thyroplasty. Even though a previously published preliminary report showed that $VoCoM^{\circledR}$ is a convenient and safe product for the type I thyroplasty, further investigations or experiences are yet to be reported. Authors aimed to evaluate the efficacy of $VoCoM^{\circledR}$type I thyroplasty, and its advantage and/or disadvantage. Materials and Method : Twenty three consecutive patients with unilateral vocal cord palsy enrolled for the study, who received type I thyroplasty with $VoCoM^{\circledR}$ between July 2001 and June 2003. Acoustic, aerodynamic and stoboscopic analyses were performed prior to surgery and 1 to 3 months after surgery. Speech language pathologists evaluated their voice quality by GRBAS scale, and patients themselves reported subjective changes of their voice by visual analog scale. Results : The average time for the operation was 80 min, which is about 30 min less than other methods. Preoperative jitter was 3.25$\pm$1.65% and improved to 1.94$\pm$1.79% postoperatively (p<0.05). Preoperative shimmer was 9.72$\pm$6.56% and improved to 5.61 $\pm$3.76% (p<0.05), Maximal phonation time increased from 4.41$\pm$2.99 to 7.98$\pm$4.35 sec (p<0.05) The postoperative stroboscopy revealed an effective medialization in 91.3% of the patients. The subjective phonetic improvements were reported in 21 out of 23 patients. GRBAS scale improved from 2.71$\pm$0.46 to 1.47$\pm$1.12(p<0.05). Additional medialization with $Gore-Tex^{\circledR}$ was easily performed in two revision cases. Previously inserted $VoCoM^{\circledR}$ implant was hard to remove because of the tight integration of soft tissues around the implant. Side effects such as extrusion or foreign body reaction are not observed. $VoCoM^{\circledR}$ was relatively expensive and costed more than 10 times of $Gore-Tex^{\circledR}$. Conclusion : Prefabricated hydroxylapatitie implant($VoCoM^{\circledR}$) provides a convenient, safe and efficient way of vocal fold medialization. However it is relatively expensive and hard to remove.

• 대한치과보철학회지
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• 제55권2호
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• pp.198-204
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• 2017

악안면부의 결손은 선천적으로 결손을 가지고 있거나 외상이나 수술적인 절제 등에 의한 후천적 원인에 의해 발생할 수 있다. 특히 구강 내 결손을 가진 환자 중 상악의 결손과 연관되어 있는 경우가 높은 비중을 차지하고 있으며 보철적 치료의 필요성이 높다. 하악의 부분적 결손을 가질 경우 기능적 회복에 상당한 한계점을 보이나 양측 턱관절이 정상적으로 남아 있을 경우 국소의치를 이용한 악안면 보철물을 제작함으로써 양호한 결과를 기대할 수 있다. 본 증례의 환자는 58세 남자 환자로서 안면부 총상으로 인한 구개부 및 좌측 하악 구치부 결손을 가진 분으로 obturator와 하악 RPD 재제작을 위해 내원하였다. 환자의 상악 결손 범위는 Aramany 분류법 Class IV에 해당되는 상태이며, 하악은 Cantor와 Curtis 분류법 Type V resection 상태이다. 상, 하악의 우측 구치부가 잔존하였으나, 수술 후 악골 변형으로 인해 서로 교합되지 않았으며 치주상태 불량으로 인한 동요도도 존재하는 상태였다. Obturator의 유지를 위해 잔존 지대치를 최대한 활용하였고 안정적인 교합이 형성되도록 치아를 배열하였다. 하악 RPD는 하악 절제술로 변형된 연조직에 적합하도록 제한된 범위를 피개하는 RPD를 제작하였다. 이에 환자분의 저작, 연하, 발음 기능이 많이 개선되었으며 만족할 만한 결과를 보여주어 본 증례를 발표하는 바이다.

• 대한치과기공학회지
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• 제31권1호
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• pp.63-74
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• 2009

Partial or complete prosthesis is needed when teeth are lost due to various kinds of reason. Artificial teeth recover occlusion instead of natural teeth. Artificial teeth are required of esthetics, fragile resistance and abrasive resistance. Artificial tooth is made of acrylic resin or porcelain. Nowadays, acrylic resin artificial teeth are mainly used. Acrylic resin teeth are occluded with natural teeth, gold alloy, Ni-Cr alloy or porcelain etc. Acrylic resin teeth have similar translucency, gloss of natural teeth. And it has good chemical bond with denture base material, but it has low wear resistance. The aim of this study is to compare wear resistance among several denture teeth(Endura, SR-orthosit-PE, Planustar) and between artificial resin denture teeth and opposing 3 restorative materials(gold, Ni-Cr alloy, porcelain). Wear tests were conducted with a rotating wear testing apparatus(pin-on-disk type wear tester) under conditions of rpm 180, 75 minutes and constant loading of 50N. The upper part was the cusp of maxillary first molar and the lower part was a disk type restorative materials. To make similar oral environment, water was supplied continually. The acrylic resin teeth wear was determined by weighing the cusp each 5 minutes during 75 minutes test. Vicker's hardness tester was used to evaluate the surface hardness of test specimens. The SEM was used to evaluate the wear surfaces. The results were as follows: 1. Wear rates of acrylic resin teeth opposing to the restorative materials were high in order of Porcelain, Gold, Ni-Cr alloy (p<.05). 2. Wear resistance rate opposing to the Porcelain disk, was shown in order of Endura, SR-orthosit-PE, Planustar. The wear rate of opposing to porcelain disk was above two times more than that of other groups (p<.05). 3. Wear resistance rates opposing to the Gold, Ni-Cr alloy disk, was shown in order of Endura, SR-orthosit-PE, Planustar (p<.05). 4. A degree of the surface hardness is directly proportional to the degree of wear resistance. There are statistically significant differences between each groups (p<.05).

• 대한치과기공학회지
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• 제41권4호
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• pp.255-262
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• 2019

Purpose: Recently, the production technology of dental prosthesis using 3D Printer workpeices has been developed. However, the lack of information on the work processes and casting techniques of materials for 3D printing casting is expected to require research. Therefore, in this study, we intend to cast a Dental DLP 3D Printer workpiece, which is being commercialized, to identify its appearance and internal clearance, and to observe its castability. Methods: Castability of the 3D Printer workpiece was evaluated. The specimen is prepared in a cylindrical shape and in a 1 mm thick coping shape. The control specimen is made of wax and the experimental specimen is made of resin using two types of 3D printers. After casting, the appearance of the casting body was observed and the internal clearance of the coping was measured. Results: RP1 and RP2, cylindrical specimens, were partially cast or fin. When coping-type specimens were measured before casting, the internal clearance of PE2 was more accurate than that of PC and PE1. When coping-type specimens were measured after casting, CE1 was the most accurate in occlusal clearance and CE2n was the most accurate in axial clearance. Conclusion: 1. Exterior observations of the casting body indicated casting defects and fins. 2. Internal clearance observations show that the occlusal clearance of the castings is larger after casting, and the axial clearance of the castings is smaller after casting. 3. It is judged that the RP2 specimen is more likely to be applied for casting than the RP1 specimen.

• Journal of Chest Surgery
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• 제29권4호
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• pp.440-443
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• 1996

삼첨 판막 심내막염은 감수성이 있는 항생제에 효과적으로 치료될 수 있다. 그러나 패혈증이 지속되거 나, 중증의 심부전, 다발성 폐 색전증 그리고 실 초음파상 증식증 (vegetation)이 있는 경우는 수술이 필요 하다. . 19세횝 남자환자가 감염성심내막염으로 입원하였다. 환자는 9년전에 perimembranous type의 VSD로 수술받은 병 력 이 있다. 심초음파상 삼첨판의 전엽부에 커다란 증식증의 소견이 보였고,과거에 VSD를 봉합했던 부위에 누 출 (leakage)을 통한 좌우단락이 관찰되었다. 항생제치료와 함께 인공판막치 환술을 시행하였다. St. Jude Medical 양엽판막 (size 33 mm으로 삼첨 판막 대 치술을 시 행하였고 잔여 VSD는 단순봉합으 로 폐쇄하였다. 술후 시행한 심초음파검사에서 치환된 삼첨 판막의 기능은 좋았고, 증식증과 좌우단락의 소견은 보이지 않았다. 환자는 합병증없이 술후 25일째에 퇴원하였다. 저자들이 경험한 본 증례는 잔여 VSD로 인해 생긴 감염성심내막염을 초기에 적극적인 수술을 시행 하여 좋은결과를 얻었음을 보여준다. 이 에 문헌고찰과 더불어 보고하는 바이다.