• 제어로봇시스템학회논문지
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• 제16권9호
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• pp.840-845
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• 2010

This paper proposes the method indirectly measuring the operating force of the end-effect tip of surgical robot instrument which conducts the surgical operation in the body on behalf of the surgeon's hand. Due to the size and safety obligation to the surgical robot instrument, it is difficult to measure the operation force of its tip like grasping force. However the instrument is driven by cable-pulley torque transmission mechanism and when some force is occurred at the tip, then the reaction force appears on the cable as additional tension. Based on this phenomenon, this paper proposes a method to estimate the operating force from measuring reaction force against the driving motor by using a loadcell. And it induces mathematical equation to calculate the force from loadcell by approaching the modulus of elasticity to high order polynomial. And this paper proves the validity of proposed mechanism by experimental test.

• Clinical and Experimental Pediatrics
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• 제56권4호
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• pp.182-185
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• 2013

Children have a natural tendency to explore objects with their mouths; this can result in the swallowing of foreign objects. Most ingested foreign bodies pass uneventfully through the gastrointestinal tract. However, some foreign bodies cause obstruction or perforation of the gastrointestinal tract, requiring surgical intervention. Perforation of the gastrointestinal tract may be associated with considerable morbidity and mortality. The most common sites of intestinal foreign body perforation are the ileocecal and rectosigmoid regions. Foreign body perforation of the duodenum is relatively uncommon. We report the first Korean case of duodenal perforation by an ingested 8-cm lollipop stick. Lollipops are popular with the children and fairly accessible to them, as most parents are not aware of their potential harm. Pediatric clinicians should be aware of the risks associated with lollipop stick ingestion. Our report also describes the feasibility and safety of laparoscopic diagnosis and management of pediatric patients with peritonitis induced by the ingestion of foreign bodies.

• 제어로봇시스템학회논문지
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• 제20권8호
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• pp.801-806
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• 2014

LAS (Laparoscopy Assisted Surgery) has been substituted alternatively for traditional open surgery. However, when using a commercialized robot assisted laparoscopic such as Da Vinci, surgeons have encountered some problems due to having to depend only on information by visual feedback. To solve this problem, a haptic function is required. In order to realize the haptic teleoperation system, a force feedback and bilateral control system are needed. Previous research showed that the perturbation value estimated by a SPO (Sliding Perturbation Observer) followed a reaction force that loaded on the surgical robot instrument. Thus, in this paper, the force feedback problem of surgical robots is solved through the reaction force estimation method. This paper then introduces the possibility of the haptic function realization of a laparoscopic surgery robot using a bilateral control system. For bilateral control, the master uses an impedance control and the slave uses a SMC (Sliding Mode Control). The experiment results show that a torque and force sensorless teleoperation system can be implemented using a bilateral control structure.

• Clinical and Experimental Reproductive Medicine
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• 제42권3호
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• pp.126-129
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• 2015

Essure (Bayer) received approval from the U.S. Food and Drugs Administration as a permanent non-hormonal contraceptive implant in November 2002. While the use of Essure in the management of hydrosalpinx prior to in vitro fertilization (IVF) remains off-label, it has been used specifically for this purpose since at least 2007. Although most published reports on Essure placement before IVF have been reassuring, clinical experience remains limited, and no randomized studies have demonstrated the safety or efficacy of Essure in this context. In fact, no published guidelines deal with patient selection or counseling regarding the Essure procedure specifically in the context of IVF. Although Essure is an irreversible birth control option, some patients request the surgical removal of the implants for various reasons. While these patients could eventually undergo hysterectomy, at present no standardized technique exists for simple Essure removal with conservation of the uterus. This article emphasizes new aspects of the Essure procedure, as we describe the first known association between the placement of Essure implants and the subsequent development of fluid within the uterine cavity, which resolved after the surgical removal of both devices.

• Advances in pediatric surgery
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• 제19권2호
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• pp.90-97
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• 2013

Laparoscopic surgery has become popular in the past few decades, owing to less postoperative pain, fast recovery, and better cosmetic outcomes. The laparoscopic approach has been employed in pediatric surgery for the same reasons. After the first attempts of single incision laparoscopic appendectomy in pediatrics in 1998, single incision laparoscopic surgery (SILS) has recently been proven to be safe and feasible for the pediatric population. However, limitations have been reported for SILS, such as the wide learning curve, compared to standard laparoscopic surgery, and the restricted number of hospitals with surgical training programs including SILS. In this study, we intend to present our initial experiences with SILS in children, and to describe the technique, instruments used, and outcomes. This is a retrospective study of 71 pediatric patients who underwent SILS, at a tertiary medical center, between September, 2012 and August, 2013. Electronic medical records were reviewed for demographics, type of procedure, operation time, use of additional ports, conversion to open surgery, complications and hospital stay. Additional ports were inserted in 4 cases, for the purpose of traction. Postoperative complications were noted in 13 cases, which were mostly related to wound inflammation or formation of granulation tissue. According to our analyses, patients with complications had significantly longer use and more frequent use of pain killers. Notwithstanding the small sample size, many of the procedures performed in pediatric patients seem to be possible with SILS.

• Journal of Gastric Cancer
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• 제12권1호
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• pp.46-48
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• 2012

A trocar site hernia is a rare complication. We report a patient who had an abdominal wall mass at a previous trocar site after laparoscopic distal gastrectomy. It was diagnosed as omental herniation and fat necrosis. We conclude that patients with trocar site masses exhibiting fat density on a computed tomography scan could be followed up without surgery, and that fascial defects located at 10-mm or larger trocar sites should be closed whenever possible to prevent hernia formation.

• Journal of Gastric Cancer
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• 제16권3호
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• pp.200-206
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• 2016

In Korea, proximal gastrectomy has recently attracted attention as a better choice of function-preserving surgery for proximal early gastric cancer than total gastrectomy. Of the various strategies to overcome reflux symptoms from remnant stomach, double tract reconstruction not only reduces the incidence of anastomosis-related complications, but is also sufficiently reproducible as a laparoscopic procedure. Catching up with the recent rise of single-port laparoscopic surgeries, we performed a pure single-port laparoscopic proximal gastrectomy with DTR. This procedure was designed by merging the function-preserving concept of proximal gastrectomy with single-port laparoscopic total gastrectomy.

• Journal of Gastric Cancer
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• 제18권2호
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• pp.152-160
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• 2018

Purpose: Totally laparoscopic gastrectomy (TLG) for advanced gastric cancer (AGC) is a technically and oncologically challenging procedure for surgeons. This study aimed to compare the oncologic feasibility and technical safety of TLG for AGC versus early gastric cancer (EGC). Materials and Methods: Between 2011 and 2016, 535 patients (EGC, 375; AGC, 160) underwent curative TLG for gastric cancer. Clinicopathologic characteristics and surgical outcomes of both patient groups were analyzed and compared. Results: Patients with AGC required a longer operation time and experienced more intraoperative blood loss than those with EGC did. However, patients from both the AGC and EGC groups demonstrated similar short-term surgical outcomes such as postoperative morbidity (14.4% vs. 13.3%, P=0.626), mortality (0% vs. 0.5%, P=0.879), time-to-first oral intake (2.7 days for both groups, P=0.830), and postoperative hospital stay (10.2 days vs. 10.1 days, P=0.886). D2 lymph node dissection could be achieved in the AGC group (95%), with an adequate number of lymph nodes being dissected ($36.0{\pm}14.9$). In the AGC group, the 3-year overall and disease-free survival rates were 80.5% and 73.7%, respectively. Conclusions: TLG is as safe and effective for AGC as it is for EGC.

• Journal of Chest Surgery
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• 제42권5호
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• pp.645-648
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• 2009

저자들은 우리나라에서는 처음으로 복강경을 이용한 수기보조 방법으로 복부 대동맥류 치환술을 시행하였다. 환자는 67세 남자였으며, 복부 대동맥류의 직경은 약 5.8 cm였다. 첫 단계로 상복부에 6 cm 절개선을 내고, 복강경하에서 집도의의 왼손을 이용하여 대동맥류 주위를 박리하였다. 근위부 문합은 절개창을 통하여 직접 하였으며, 인조혈관의 양쪽 다리를 후복막을 통하여 양족 서혜부에서 총대퇴동맥과 단측문합하였다. 환자는 술 후 6시간 후 경구 식이를 시작하였으며, 술 후 4일째 퇴원하였다.

• Advances in pediatric surgery
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• 제17권1호
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• pp.58-64
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• 2011

Minimally invasive techniques for pediatric inguinal hernia repair have been evolving in recent years. We applied the laparoscopic method to repair pediatric inguinal hernia using the techniques of sac transection and intra-corporeal ligation. Between November 2008 and August 2010, 67 pediatric patients (47 boys and 20 girls) with inguinal hernias were included in this study. Postoperative activities, pain, and complication were checked prospectively at regular follow-up. One patient presented with clinically bilateral hernia, and three patients had metachronous hernias. Thirty-two cases out of 63 patients with unilateral hernias had a patent processus vaginalis on the contralateral side. Mean operation time was $35{\pm}11.4$ minutes for unilateral hernias and $43{\pm}11$ minutes for bilateral hernias. There were no intra-operative complications. One patient had a small hematoma on the groin postoperatively, which subsided spontaneously in a week. Recurrence and metachronous hernia were not found at follow up. In summary, laparoscopic inguinal repair in children is safe, easy to perform and has an additional advantage of contralateral exploration. Further studies should include long term follow-up.