경항문 내시경 수술 도구에서의 최적 활동 반경 개선을 위한 컴퓨터 시뮬레이션 연구

김형태,김광기,남경원,김현호,손대경,Kim, Hyung-Tae,Kim, Kwang-Gi,Sohn, Dae-Kyung,Kim, Hyun-Ho,Nam, Kyoung-Won 대한의용생체공학회 2009 의공학회지 Vol.30 No.6

Conventional devices for transanal endoscopic microsurgery that are currently used clinically for intestine or rectal cancer patients have 40 mm external diameter of rectoscope tube - induces anal damage and long-term postoperative pain for small-sized patients. In this paper, we designed rectum and rectoscope models and calculated the changing trends of operation area of the surgical tools in accordance with the step-by-step variation of design parameters of the rectoscope tube - external diameter, axial length, and distal angle. Using the results of computer simulation, we suggested an optimal set of design parameters that minimizes external diameter of the rectoscope tube and at the same time, maintains similar operation area of the surgical tools compared with commercialized devices (${\geq}\;4274.7mm^2$). The results of the simulation showed that the optimal design parameters were 35 mm external diameter, 100 mm axial length, and $45^{\circ}$ distal angle of the rectoscope tube. This result can be applied to the development of endoscopic microsurgery device that can minimize side effects to the intestine or rectal cancer patients.

심한 소장침범을 보인 Henoch-Schonlein Purpura의 치료 2례

김형태,문진수,장현오,조희승,이종국,김기홍,서정욱,김민경,Kim, Hyung Tae,Moon, Jin Soo,Jang, Hyun Oh,Jo, Heui Seung,Lee, Jong Guk,Kim, Ki Hong,Seo, Jung Wook,Kim, Min Kyung 대한소아소화기영양학회 2004 Pediatric gastroenterology, hepatology & nutrition Vol.7 No.1

보존적인 스테로이드 치료로 호전이 없는 심한 복부증상을 동반한 HSP 환자의 치료에는 아직까지 정설이 없으나, 저자들은 면역글로불린 정맥투여로 증상이 호전된 증례와 소장의 경장괴사를 동반하고 수술적 치료로 호전된 증례를 경험하였기에 문헌고찰과 함께 보고하는 바이다. Henoch-$Sch{\ddot{o}}nlein$ purpura (HSP) is a vasculitis of the small vessels in skin, joints, gastrointestinal (GI) tract and kidney. GI symptoms occur in up to 85% of patients and may lead to severe problems such as intussusception, obstruction, and perforation. GI symptoms may not be easily controlled, showing refractoriness to the conventional corticosteroid therapy. Although GI involvements of HSP are acute, and self-limited in most instances, they may cause fatal results in some unusual cases. In such conditions all the possible therapeutic modalities should be considered. We report two cases of severe small bowel involvement of HSP. One case presented with severe abdominal pain showing refractoriness to corticosteroid, but improved with IV immunoglobulin therapy. In the second case, HSP with transmural infarction in the small bowel could be cured with surgical intervention.

학술 4 - 최신 외과 수술 기계(VESSEL SEALING SYSTEM)

김형태,Kim, Hyeong-Tae 대한수의사회 2014 대한수의사회지 Vol.50 No.7

학술 6 - 미세 현미경을 통한 척추 디스크 수술

김형태,Kim, Hyeong-Tae 대한수의사회 2014 대한수의사회지 Vol.50 No.6

특이점분포방식(特異點分布方式)에 의한 비정상수중익문제(非正常水中翼問題)의 해석(解析) -제2보(第2報) 3차원(次元) 문제(問題)로의 확장(擴張)-

김형태,이창섭,Hyoung-Tae,Kim,Chang-Sup,Lee 대한조선학회 1983 大韓造船學會誌 Vol.20 No.3

In this paper a discrete-vortex-method(DVM) is presented for investigating the hydromechanics of the planar hydrofoils performing the undulatory motion which can be related to fish propulsion with carangiform mode. This is an extention of the authors previous work(1981) on the 2-dimensional hydrofoil. The applicability and accuracy of the present method are shown by means of comparing the calculated lifts and moments, and their distributions over the planforms with those in available references, for aspect ratio 1.0 and 2.0 rectangular hydrofoils and a swept-back hydrofoil of aspect ratio 2.0 from reduced frequency 0.1 to 0.5. The agreement is considered good. To assure the applicability of the DVM to the study of the propulsive performance of the oscillating planar hydrofoils, the convergence tests are performed. The mean thrust(in pure heave, this is wholly due to leading-edge suction), the mean power to maintain the motion and the hydromechanical efficiency are calculated for the rectangular hydrofoil of aspect ratio 8.0 and these are compared with the calculations by Chopra & Kambe(1977) and Lan(1979) for the same cases.

하악골의 발육중인 생쥐에서 기능력의 변화가 특이-유전자 발현에 미치는 영향

김형태,박주철,이창섭,박헌동,Kim, Hyung-Tae,Park, Joo-Cheol,Lee, Chang-Seop,Park, Heon-Dong 대한소아치과학회 2003 大韓小兒齒科學會誌 Vol.30 No.2

기능력은 뼈의 형성, 유지 및 개조 이외에도 치아이동, 교정치료, 기능성 악교정장치의 사용 등과 관련한 치주인대세포의 특성 변화 등에 중요한 영향을 미친다. 또한, 하악과두에서도 기능력의 변화에 따라서 다양한 특성의 변화가 나타난다. 본 연구에서는 ICR 생쥐를 8주 동안 soft-diet와 hard-diet의 식이 조절을 통해 기능력의 변화를 유도하여, 기능력의 변화와 관련한 특이 유전자를 검출하기 위하여 subtractive hybridization, northern 분석 및 mRNA in-situ hybidization 등의 실험을 시행하여 다음과 같은 결과를 얻었다. 1. Soft-diet군과 hard-diet군의 subtractive hybridization을 통하여 총 39개의 clone을 얻었고 이중에서 11개의 서로 다른 hard-diet군 특이 후보 유전자들을 분리하였다. 2. 11개의 후보 유전자들 중에서 homology 검색과 northern 분석을 통하여 기능력과 관련이 있을 것으로 생각되거나 hard-diet군에서 mRNA가 선택적으로 발현되는 FS-s2, FS-s5, FS-s18 및 Fs-s22 유전자를 선택하였다. 3. Soft-diet군과 hard-diet군의 형태학적 분석에서 soft-diet군은 hard-diet군에 비하여 골모세포의 활성과 골개조의 특성은 저하된 것으로 관찰되었으나, 하악과두의 연골성골화 과정은 오랜 시간동안 지속되는 것으로 나타났다. 4. FS-s2, FS-s5, FS-s18 및 Fs-s22 유전자의 cRNA 탐침자를 이용한 in-situ hybridization에서 4개의 유전자의 mRNA들은 hard-diet군의 세포들에서는 강하게 발현되었으나 soft-diet군의 세포들에서는 그 발현이 미약하거나 나타나지 않았다. 이상의 결과를 종합하여 FS-s2, FS-s5, FS-s18 및 Fs-s22 유전자들은 대부분이 기능이 거의 알려져 있지 않는 것들로 기능력의 변화 과정에서 중요한 역할을 할 것으로 생각되나 앞으로 보완 연구를 통하여 각 각의 유전자들의 보다 정확한 기능을 이해하는 것이 필요 할 것으로 사료된다. Mechanical forces are known to have an effect on bone formation, maintenance and remodeling, and there is evidence that the development of the mandibular condyle in the rat or mouse is influenced by altered functional force. However, studies are lacking in molecular-biologic mechanism such as the identification of differentiation factor induced from functional force. Here a mouse model was used to investigate the functional stress-responsive gene or factors which is related to the altered force by comparing the expression genes of functional state and hypo-functional state of the mouse mandible. ICR mice were provisioned with either a soft, mushy diet (soft-diet group) or hard rat pellets (hard-diet group) beginning at weaning for the alteration of functional force and subsequently sacrificed at 89 days of age. Incisor of mice in group 1 were trimmed twice a week to reduce occlusal forces. After killing the animals, mandibular bone including condyle were collected for RNA extraction, subtractive hybridization, northern blot analysis and mRNA in-situ hybridization. The results as follows; 1. A total of 39 clones were sequenced, and 11 individual sequence types were subsequently identified by subtractive hybridization, as 28 clones were represented twice in the analyzed sets. 2. Consequently four candidate clones, FS-s (functional stress-specific)2, -5, -18, and -22 were identified and characterized by homolgy search and northern analysis. Four of these clones, FS-s2, -5, -18, and -22, were shown to be expressed differentially in the hard-diet group. 3. Histologic sections showed that osteoblastic activity along the bone trabeculae and active bone remodeling were significantly lower in soft than in hard diet animals. A soft diet seems to enable a longer period of endochondral ossification in the mandibular condyle. 4. Although the mRNAs of FS-s2, -5, -18, and -22 were expressed rarely by cells of the soft-diet group, highest expression was detected in the cells of the hard-diet group. Together with the above results, it is suggested that FS-s2, -5, -18, and -22 could act as an important factors controlling the tissue changes in response to functional stress. The exact functional significance of these findings remains to be established.

기획기사-인력선 경주대회 소개

김형태,강대선,Kim, Hyeong-Tae,Gang, Dae-Seon 선박안전기술공단 2005 선박안전 Vol.20 No.-

가임신 흰쥐에 있어서 자궁척출 및 Prostaglandin F2α 투여가 혈청 Progesterone 의 농도 및 황체에 미치는 영향

김형태,정영채,김창근 ( Hyung Tae Kim,Yung Chai Chung,Chang Keun Kim ) 한국축산학회 1981 한국축산학회지 Vol.23 No.4

The purpose of this experiment was to investigate the effects of hysterectomy and administration of PGF₂α on serum progesterone level and corpus luteum in pesudopregnant rats. PGF₂α administration or hysterectomy was performed at day S of pseudopregnancy. Five rats from each group were randomly sacrificed at day 5,6,7,8,9 and 12 of pseudopregnancy for assay of serum progesterone level and microscopic observation of ovary. The results obtained were as follows; 1. In both normal and hysterectomized groups, PGF₂α administration caused significant reduction in serum progesterone level to 24.2% and 30.8% at day 6 and to 11.3% and 34.3% at day 9 of pseudopregnancy as compared with pretreatment level. The serum progesterone level of hysterectomized group untreated with PGF₂α remained elevated until day 12 of pseudopregnancy as compared to those of other three groups. 2. The ovarian weights of control group treated with PGF₂α were significantly reduced as compared to those of other three groups at day 9 of pseudopregnancy (p$lt;0.05). 3. The number of corpus luteum in groups treated with PGF₂α was slightly reduced, but there were no significant difference between PGF₂α and non-PGF₂α treated groups at day 6,7,8,9 of pseudopregnancy. 4. The number of lutein cell in corpus luteum of PGF₂α treated groups on day 9 of pseudopregnancy was significantly lower than those of PGF₂α untreated groups (p$lt;0.05).

GUST 중에서의 2차원 수중익 해석

김형태,이창섭,양승일,Kim, Hyeong-Tae,Lee, Chang-Seop,Yang, Seung-Il 한국기계연구원 1982 기계연구원소보 Vol.4 No.2

In this paper, a classical gust problem is treated by using the numerical lifting¬-surface theory to verify the effect of gust-a sudden fluctuating fluid velocity around an object, which is normal to the main stream direction-on the hydrody¬namic forces, especially the mean thrust in upstream direction, acting on the two¬-dimensional flat plate. In this case, the mean thrust wholly resorts to the leading edge suction, and it is the same situation to the case of the heaving plate in uniform flow. The ph¬enomenon of leading edge suction is very important for the flapping propulsion of animals, typical to fish and birds, and can be related to the prediction of the hydrodynamic forces acting on marine propellers operating in gustlike wakes of ships. The results of this paper can be easily superposed to those of the reference [1J in order to solve the problem of the two-dimensional oscillacting plate in gust

수정 발진기의 제조기술 현황과 전망

김형태,Kim, Hyeong-Tae 한국전자정보통신산업진흥회 1990 電子振興 Vol.10 No.6

전자산업의 급속한 성장에 따라 수정응용산업도 지속적인 성장을 해왔으나 기술적인 측면에서 균형적인 발전이 이루어지지 않아 부품기술 수준이 완제품 개발을 뒷바침 하지 못나는 실정으로서 사실상 기술집약형 고부가가치 제품은 수입에 의존하고 저부가가치 제품을 국내 생산을 통해 해외로 수출하고 있는 상황이다.