• Journal of Veterinary Clinics
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• v.31 no.6
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• pp.477-482
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• 2014

The aim of this study was to investigate and compare technique, surgical time, and complications of laparoscopic ovariectomy using $LigaSure^{TM}$ and bipolar vessel sealing system in cats. Laparoscopic ovariectomy was performed under general anesthesia on 10 healthy female cats admitted for elective ovariectomy. Surgery was performed through three midline portals. Each ovary was randomly-assigned to removal by use of either $LigaSure^{TM}$ or bipolar vessel sealing system. Duration of predetermined surgery intervals and complications were compared. Bipolar OVE ($2:16{\pm}1:14$ minutes) took significantly longer surgical time compared to the $LigaSure^{TM}$ OVE ($1:24{\pm}0:59$ minutes, P = 0.021). The ovarian pedicle fat and obesity did not influence surgery duration. Intraoperative hemorrhage occurred with bipolar OVE in three cats, but had no significant influence on surgical time. The results suggest that both $LigaSure^{TM}$ and bipolar devices appear to be effective, but $LigaSure^{TM}$ can be used as a stand-alone device that decreases surgical time and complication compared with bipolar vessel sealing system.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.4
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• pp.1-7
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• 2015

In the present study, copper micromolds with a microhole array were precisely manufactured by a synchrotron LIGA process. Like in the traditional LIGA process, a deep X-ray lithography based on a synchrotron radiation was employed as the first manufacturing step. Due to the excellent optical performance of the synchrotron X-ray used, cylindrical micropillar arrays with high aspect ratio could be efficiently obtained. The fabricated microfeatures were then used as a master of the subsequent copper electroforming process, thereby resulting in copper micromolds with a microhole array. Thermoplastic hot embossing experiments with the copper micromolds were carried out for imprinting cylindrical microfeatures onto a polystyrene sheet. Through the hot embossing, the effect of embossing temperature and usefulness of the present manufacturing method could be verified.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.12
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• pp.1871-1876
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• 2004

We demonstrate a novel fabrication technology for the microneedle array that can be used in the medical test field, which is transdermal drug delivery and blood analyte sampling. Previous researchers have used silicon-processed micromachining, a reactive ion etching, and molding techniques for the fabrication of microneedle array. However, these fabrication techniques have somewhat limitations apply to the microneedle array fabrication according to its application. Inclined LIGA process is suggested to overcome these problems. This process provides easier, sharper and longer out-of-plane microneedle array structure than conventional silicon-processed fabrication method did. Additionally, because of the advantage of the LIGA process based on mold fabrication for mass production, the polymer, PMMA(PolyMethylMethAcrylate), based microneedle array is useful as the mold base of nickel electroplating process; on the other hand, silicon-processed microneedle array is used in itself. In this research, we fabricate different types of out-of-plane microneedle array, which have different shape of tip, base and hole structure, using the inclined LIGA process. The fabricated microneedles have proper mechanical strength, height and sharpness to puncture human hand epidermis or dermis with less pain and without needle tip break during penetrating the skin.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.733-736
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• 2000

In the first step of the LIGA process a resist layer, typically PMMA(polymethylmethacrylate), is pattered by deep X-ray lithography. Then the exposed parts are dissolved by an organic developer. To describe the developer. To describe the development course the parameters influencing the development process was investigated. The developed depth is proportional to the square root of the development time which suggests that the development rate increases with increasing dose value and temperature. So the development course can be described by a phenomenological equation.

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.70-71
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• 2004

Back light unit(BLU) using a microlens fabricated by the modified LIGA process for the liquid crystal display(LCD) is proposed, and some experimental results are presented. To realize the back light unit using microlens pattern, LIGA and reflow process are used.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.2049-2053
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• 2016

Background: The LigaSure vessel sealing system has been proposed to save operation time and reduce intraoperative blood loss for various surgeries. However, its usage for gastric cancer is still controversial. The aim of the present meta-analysis was to compare the effectiveness of LigaSure with conventional surgery in gastrectomy. Materials and Methods: Sources were retrieved from the Cochrane Library, MEDLINE, EMBASE, SCOPUS and Google Scholar until February, 2015. All randomized controlled trials comparing LigaSure with conventional surgery in curative gastric cancer resection were selected. After data extraction, statistics were performed by Review Manager 5.1 software. Results: Three eligible randomized controlled trials were evaluated, with a total of 335 patients. The quality of the included trials was good, yet some methodological and clinical heterogeneity existed. There were no significant differences between the LigaSure and conventional groups in operative time (weighted mean difference [WMD], -22.95 minutes; 95% confidence interval [CI], [-59.75, 13.85]; P = 0.22), blood loss (WMD, -45.8 ml; 95% CI, [-134.5, 42.90]; P = 0.31), nor the incidence of surgical complications (odds ratio, 1.18; 95% CI, [0.68, 2.05]; P = 0.54). But there was a longer duration of hospital stay in LigaSure group (WMD, 1.41 days; 95% CI, [0.14, 2.68]; P = 0.03). Conclusions: All available randomized evidence has been summarized. LigaSure does not confer significant advantage over conventional surgery for curative gastric cancer resection. The usefulness of the device may be limited in gastrectomy. But, more trials are needed for further assessment of the LigaSure system for gastric cancer.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.757-758
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• 2012

• Transactions of Materials Processing
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• v.15 no.1 s.82
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• pp.34-41
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• 2006

Microlens arrays were fabricated by a modified LIGA process composed of the exposure of a PMMA (Polymethylmethacrylate) sheet to deep x-rays and subsequent thermal treatment. A successful modeling and analyses for microlens formation were presented according to the experimental procedure. A nickel mold insert was fabricated by the nickel electroforming process on the PMMA microlens arrays fabricated by the modified LIGA process. For the replication of microlens arrays having various diameters with different foci on the same substrate, both hot embossing and microinjection molding processes have been successfully utilized with the fabricated mold insert. Replicated microlenses showed very good surface roughness with the order of 1 nm. The focal lengths of the injection molded microlenses were successfully estimated theoretically and also measured experimentally.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.945-949
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• 2003

LIGA(Lithographie Galvanoformung Abformung), a fabrication method for the production of microstructrues with a high aspect ratio, is now playing an important role in a fabrication of polymeric optical waveguide device as the replication processes have been developed such as hot embossing and injection molding. The present report deals with the fabrication of Ni master used for the replication of multi-mode polymeric optical waveguide. With the basic technological features in the sequence of the LIGA technique, we fabricated Ni master with 12 channel microstructures of $100\;{\times}\;100{\mu}m\;^2{\times}\;60mm$, and achieved an accuracy of ${\pm}1\;{\mu}m$. Manufactured polymeric optical wavegude with the same using hot embossing process has also the same accuracy and approved its mass production capability.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.7
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• pp.36-44
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• 2000

X-선 사진식각공정(이하 LIGA 기술이라 함)을 이용한 초소형, 초정밀 금형 및 3차원 구조물 제작 가공기술은, 생산기반 기술 중 금형기술 및 가공기술 분야에 해당하는 기술로 포항가속기와 같은 방사선 가속기에서 생성되는 수 보대 파장의 X-선을 이용하는 기술이다. 짧은 파장을 사용하는 연유로, 일반 반도체 공정으로는 실현할 수 없는 높고, 광학적 용도까지 가능한 거울정도의 벽면 거칠기(수백${\AA}$이하)를, 그러면서도 서브 마이크론의 정밀도 (1$\mu\textrm{m}$이하)를 가지는 금형 및 3차원 구조물을 일괄 가공할 수 있는 기술이다.(중략)