피부과 영역에서의 레이저

최지호 (Jee Ho Choi) 대한피부과학회 1994 대한피부과학회지 Vol.32 No.2

레이저의 기본 개념은 1917년 아인슈타인에 의해서 처음 기술되었으며 1960년대부터 의학 분야에 치료 목적으로 이용되기 시작하여 최근에는 다양한 종류의 레이저가 개발되어 사용되고 있다. 피부과 영역에서 현재 사용되고 있는 레이저는 이산화탄소 레이저(CO_2 laser), 색소 레이저(Dye laser), 구리증기 레이저(Copper vapor laser), Nd:YAG 레이저(Neodymium:Yttrium-Aluminum-Garnet laser), Q-switched 루비 레이저(Q-switched ruby laser). 아르곤 레이저(Argon laser), 알렉산드라이트 레이저(Alexandrite laser), He-Ne 레이저(Helium-Neon laser) 등이며 피부 혈관성 병변, 색소성 피부질환, 문신 및 양성 피부 종양의 제거에 이용되고 있다. 본 종설에서는 레이저의 특징, 생체조직과의 상호작용, 피부과에서 사용되고 있는 레이저의 특성 및 각종 피부질환의 치료에 대한 레이저의 응용, 레이저 치료시의 주의사항 등에 대하여 언급하고자 한다. The basic concept of the laser was first described by Einstein in 1917. Laser is an acronym for “Light Amplification by Stimulated Emission of Radiation”. The applications of laser light to the field of medicine were begun in 1960s. Since that time there has been a great increase in the development of laser technology and in the understanding of laser-target tissue interactions. The theory of selective photothermolysis means that a chromophore can be selectively damaged with a laser light of an appropriate wavelength and of a suitably short pulse duration that is shorter than the thermal relaxation time of the chromophore. The introduction of pulsed tunable dye lasers has considerably improved the treatment of vascular lesions, particularly light pink nevus flammeus in children. The argon pumped dye laser and copper vapor laser may be better for telangiectatic and the hypertrophic nevus falmmeus often seen in adults. Since the Q-switched and pulsed green light lasers are capable of selective photothermolysis of melanosomes and tattoo dyes, their efficacy has lasers are capable of selective photothermolysis of melanosomes and tottoo dyes, their efficacy has been under investigation for the treatment of pigmented lesions. The automated delivery of laser light and the risk of scarring is reduced. Further comparative study is needed to determine which lesions respond best to each laser system, and which treatment techniques are optimal. Treatment combining more than one of these laser systems may prove superior to any of them used alone.(Korean J Dermatol 1994;32(8):205~216)

Long-pulsed Er:YAG 레이저(CO3)를 이용한 안면부 주름의 치료

최준영,홍인표,김종환 대한미용성형외과학회 2005 Archives of Aesthetic Plastic Surgery Vol.11 No.2

Facial rhytides are a common problem that often presents for treatment. Laser facial skin resurfacing has become a method of treatment for photoaging and pigmentary conditions. Although excellent results can be obtained by high-energy, pulsed carbon dioxide(CO2) laser, significantly morbidity exists due to the considerable thermal damage to the skin. Long-pulsed Er:YAG laser (CO3 laser, Cynosure) combines the performance of a CO2 system with the safety and convenience of an Er:YAG. Yet the CO3 laser is more than the combination of two complementary resurfacing lasers. It brings thermal management to skin resurfacing. The CO3 effect is due to a wide range of pulse durations, up to 20 times longer than those delivered by conventional Er:YAG lasers. With the CO3 laser, the user chooses the correct depth of thermal effect for maximum safety and efficacy. The purpose of this study was to evaluate the results of the CO3 laser in the treatment of facial wrinkles. Forty-three patients, aged between 35 and 70 years, with facial wrinkles, were evaluated. Wrinkle improvement was evaluated by the patient's satisfaction, clinical improvement, and photographic analysis before and after the resurfacing procedure. The long-pulsed Er: YAG laser for facial wrinkles is a safe and effective mode for laser skin resurfacing.

577 nm 레이저 섬유주성형술의 단기 임상효과

김종민,조경진,경성은,장무환,Jong Min Kim,MD,Kyong Jin Cho,MD,Sung Eun Kyung,MD,PhD,Moo Hwan Chang,MD,PhD 대한안과학회 2014 대한안과학회지 Vol.55 No.4

Purpose: To evaluate the pressure-lowering effects of single-spot laser trabeculoplasty and patterned laser trabeculoplasty using a 577-nm wavelength laser. Methods: A total 35 eyes of 35 patients with primary open-angle glaucoma were enrolled in this study. Eighteen eyes of 18 patients were treated with 360° single-spot laser trabeculoplasty and 17 eyes of 17 patients were treated with 360° patterned laser trabeculoplasty. All patients were evaluated after laser trabeculoplasty at 1 week, 1 month, 3 months, and 6 months using slit lamp examination and Goldmann applanation tonometry. Results: At 6 months postoperatively, the single-spot laser trabeculoplasty group had a mean IOP of 15.89 ± 3.89 mm Hg with a mean IOP reduction of 37.1%, while the patterned laser trabeculoplasty group had a mean IOP of 17.57 ± 2.64 mm Hg with a mean IOP reduction of 27.1%. Conclusions: Laser trabeculoplasty with a 577-nm optically pumped semiconductor laser was safe and demonstrated an IOP lowering effect. There were no significant differences in the IOP lowering effects between the single-spot laser trabeculoplasty and the patterned laser trabeculoplasty. J Korean Ophthalmol Soc 2014;55(4):563-569

The Advent of Laser Therapies in Dermatology and Urology: Underlying Mechanisms, Recent Trends and Future Directions

이호,정연욱,Kin F. Chan 한국광학회 2009 Current Optics and Photonics Vol.13 No.3

Following their applications in cardiology, ophthalmology and dentistry among others, the advent of lasers in dermatology and urology had become the success story of the past decade. Laser-assisted treatments in dermatology and urology are mainly based on the laser-induced tissue injury/coagulation and/or ablation, depending upon the desirable clinical endpoint. In this review, we discussed the underlying mechanisms of the laser induced tissue ablation. In any medical laser application, the controlled thermal injury and coagulation, and the extent of ablation, if required, are critical. The laser thermal mechanism of injury is intricately related to the selective absorption of light and its exposure duration, similarly to the laser induced ablation. The laser ablation mechanisms were categorized into four different categories (the photo-thermally induced ablation, the photo-mechanically induced ablation, the plasma induced ablation and the photoablation) and their fundamentals are herein described. The brief history of laser treatment modality in dermatology and urology are summarized.

레이저를 이용한 3차원 공간 연출 조형에 관한 연구 -레이저아트를 중심으로-

조정호,김형기 한국일러스아트학회 2019 조형미디어학 Vol.22 No.3

Laser is a light made by humans that has an amazing characteristic that is not found in natural white light. Since it was first discovered in the 1960s, it has an infinite range of possibilities for applications based on user ideas, expresses formative forms and has a fantastic yet strong impact. The strong energy and intensity of laser are used in various forms, creating new technologies one after another and creating new industries. One of them is laser art. Because the pure color of lasers has a high degree of transparency and can make fantastic and vivid production, they can be combined with various IT technologies to make new laser art. One example is the laser-based media facade with intense effects. With the recent improvement in laser production technology, many small, high-powered lasers have been produced, and artists are producing kinetic art in combination with audio and visual. At this point, we are going to identify the characteristics of light art using laser as a technical part and visual art to find laser art as a better content production. As a research method, the characteristics of each type of laser used in media art are classified and the application method of laser art is studied accordingly. We propose a research and improvement method of the advantages and disadvantages of the technology according to the laser directing method by producing the media art using the laser. 레이저는 인간에 의해 만들어진 빛으로서 자연발생적으로 존재하는 백색광에는 없는 놀라운 특성을 갖는다. 레이저는 1960년대 처음 발견된 이후 사용자의 아이디어에 따라 응용 범위의 무한한 가능성을 갖고 있으며 조형적인 형태를 표출, 환상적이면서도 강한 Impact를 갖고 있다. 레이저가 가진 강한 에너지와 집광성은 다양한 형태로 이용되고 새로운 기술을 창조하고 산업 분야를 만들었다. 그중 하나로 레이저아트가 있다. 레이저의 순수한 빛깔은 투명도가 높고 환상적이며 생생한 연출을 할 수 있기 때문에 각종 IT 기술과 접목하여 새로운 레이저아트를 할 수 있다. 그 예의 하나로 레이저를 이용한 미디어파사드가 강렬한 효과로 연출되고 있다. 최근 레이저 생산 기술이 향상됨에 따라 소형 고출력 레이저들이 많이 생산되어 예술가들이 오디오ㆍ비주얼과 결합하여 키네틱 아트로도 제작되고 있다. 이 시점에서 레이저를 이용한 라이트아트의 특징을 기술적인 부분과 시각적 예술로서 특징을 규명하여 더 나은 콘텐츠 제작으로서의 레이저아트를 알아보고자 한다. 연구방법으로 미디어아트에 사용되어지는 레이저 종류별 특징을 분류하고 이에 따라 연출되는 레이저아트 적용방법을 연구하고자 한다. 레이저를 이용한 미디어아트를 제작하여 레이저 연출방식에 따른 기술의 장단점에 대한 연구 및 개선 방법을 제시하고자 한다.

High power-pulsed Nd:YAG laser as a new stimulus to induce BMP-2 expression in MC3T3-E1 osteoblasts

Kim, In Sook,Cho, Tae Hyung,Kim, Kwansik,Weber, Franz E.,Hwang, Soon Jung Wiley Subscription Services, Inc., A Wiley Company 2010 Lasers in surgery and medicine Vol.42 No.6

<B>Background and Objective</B><P>High-power laser has recently become a physical stimulus for bone regeneration. Little is known about how high-power laser irradiation affects osteoblast differentiation. This study investigated osteoblast responses to high-power laser and combined irradiation with BMP-2 treatment.</P><B>Study Design/Materials and Methods</B><P>MC3T3-E1 pre-osteoblasts were exposed to laser irradiation, 100 ng/ml BMP-2 or both. Cells were irradiated with a Q-switched, pulsed neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, with a 1,064 nm wavelength and 0.75 W output power under 1.5, 3, or 5 J/cm<SUP>2</SUP> energy densities. Cell proliferation was evaluated using tetrazolium salt, WST-8. To determine the effect of these treatments on in vitro osteogenesis, we examined alkaline phosphatase (ALP) activity, mineral deposition, and expression of genes associated with osteogenesis. Quantitative real time PCR or ELISA was used to examine cytokine expression. In each experiment, either non-irradiated or BMP-2 (100 ng/ml)-treated cells were used as controls.</P><B>Results</B><P>High-power, low-level, Nd:YAG laser irradiation significantly increased ALP activity, when combined with BMP-2 or not. Cell proliferation declined in the irradiation and combined irradiation/BMP-2 groups. Interestingly, Nd:YAG laser stimulation resulted in significant induction of endogenous BMP-2 protein and gene expression. The increased expression of upstream regulators cbfa1 by Nd:YAG laser alone was comparable to exogenous BMP-2 treatment (100 ng/ml). Combined laser/BMP-2 treatment was synergistic in the expression of some genes (IGF-1, cbfa1) and ALP activity, compared to both BMP-2 treatment and laser irradiation alone. In vitro matrix mineralization was significantly accelerated by laser stimulation compared to that of the control, more so than with the combined laser/BMP-2 treatment.</P><B>Conclusions</B><P>The present in vitro findings demonstrate that high-power, low-level Nd:YAG laser increased osteoblast activity, very efficiently accelerating mineral deposition. Osteoinductive effect of laser is likely mediated by activation of BMP-2-related signaling pathway. Lasers Surg. Med. 42:510–518, 2010. © 2010 Wiley–Liss, Inc.</P>

Research on the Microstructure Characteristic and Tensile Property of Laser‑MIG Hybrid Welded Joint for 5A06 Aluminum Alloy

Yanqiu Zhao,Xiaohong Zhan,Qiyu Gao,Shuai Chen,Yue Kang 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.3

Laser-metal inter gas (MIG) hybrid welding technique provides higher overall productivity over the traditional fusionwelding processes for joining medium-thick aluminum alloy. In this paper, laser-MIG hybrid welding experiment was performedby the TruDisk 12003 Laser and KUKA robot. The second fusion line, the laser-dominated region and laser-MIGhybrid-dominated region were introduced to this study to discuss the microstructure distribution. A three-dimensionalfinite element model was established by MSC. Marc to study the thermal field distribution of laser-MIG hybrid weldingprocess. It found that the temperature in the laser-MIG hybrid-dominated region was much higher than the laser-dominatedregion. The formation of the second fusion line in the welded joint is mainly owing to the different heat effect of laser-archybrid-dominated region and laser-dominated region. The crystalline size of equiaxed dendrite grains in the laser-MIGhybrid-dominated region is finer than the laser-dominated region. In addition, the tensile property was measured to dissectthe failure mechanism of the laser-MIG hybrid welding joints. The element content in fractured surface at the position ofdimple and pore wall were comprehensively analyzed. The element content of Mg and O in pore wall are higher than dimple. In the solidification process, the growth of equiaxed dendrite grains is in part hindered by the existence of coarse pores inthe laser-MIG hybrid-dominated region.

Case series of split-face, single-blinded, randomized controlled comparison of Nd:YAG 1064-nm picosecond laser versus Nd:YAG 1064-nm nanosecond laser in the treatment of pigmentary disorders

( Myoung Eun Choi ),( Seung Hwan Paik ),( Ik Jun Moon ),( Woo Jin Lee ),( Chong Hyun Won ),( Mi Woo Lee ),( Jee Ho Choi ),( Sung Eun Chang ) 대한피부과학회 2019 대한피부과학회 학술발표대회집 Vol.71 No.1

Introduction: : Q-switched nanosecond lasers demonstrated their efficacy in various pigmentary disorders. However, there are limited data to compare Q-switched ruby and neodymium (Nd:YAG) nanosecond laser to Nd:YAG picosecond laser in the treatment of mottled pigmentation, lentigo and melasma. Methods: Picosecond 1064-nm Nd:YAG laser with spot size of 7 mm, fluence of 0.6 to 0.8 J/cm2, repetition rate of 10 Hz, 3 pass was delivered with a zoom hand piece to one side of face. Nanosecond 1064-nm Nd:YAG laser was delivered to the other side of face with spot size of 7 mm, fluence of 2.0 to 2.2 J/cm2, repetition rate of 10 Hz, 3 pass. Results: Three patient of Fitzpatrick skin type 3 and two patients of Fitzpatrick skin type 4 were enrolled. Pigmentary lesions assessed with global assessment scale from 0 (no pigmentation) to 4 (severe pigmentation) decreased from 2.8 to 1.25 in average after 6 sessions. The response was faster in nanosecond laser site. One patient showed postinflammatory hyperpigmentation (PIH) after nanosecond laser treatment. Patient satisfaction was meased with global assessment scale implying that all patients were comparably satisfied with both laser treatment. Discussion: Pigmentary lesions show faster response to nanosecond laser compared to picosecond laser. Nanosecond laser was more efficient in severe cases while PIH can result in dark skin. General skin tone becomes clear and bright after picosecond laser.

Pilot study on efficacy and patient satisfaction with 1,450-nm laser boosting treatment after a thread lift procedure

Chang Hosun,Kang Kyoungjin 대한미용의학회 2022 대한미용의학회지 Vol.6 No.1

Background: Polydioxanone used in thread lifting is mostly absorbed in skin tissues within six months, and its therapeutic effect diminishes gradually. However, we often experience a decrease in the effectiveness of thread lifting within 1–2 months. We performed a laser boosting treatment to maintain the long-term effect of thread lifting and reported its additional utility. Objective: To investigated the impact of laser boosting treatment on therapeutic effect and patient satisfaction after thread lifting during the first three months. Methods: This study was conducted between March and July, 2019. Severity of jawline and mouth corner sagging were graded by Merz Scale scores in seven middle-aged female patients. After the symmetrical thread lift procedure, 1,450-nm laser boosting treatment was applied to the side of the face with higher preoperative grade. Average pain scores at postoperative day (POD) 0, 3, and 7 were compared, including changes from POD 0 to POD 3 and 7. Face halves were compared regarding improvements in elasticity, skin tone, sagging of mouth corners, jawline sagging, overall satisfaction, and Merz Scale scores after three months. Results: All the patients showed improvements in elasticity, skin tone, sagging of mouth corners, and jawline sagging with improved overall patient satisfaction. During pain assessment, five of the seven patients showed greater changes in the laser-treated side at POD 3 and 7. Comparing the Merz Scale scores, there was a significant difference between pre-and post-treatment in jawline sagging and between jawline sagging and sagging of mouth corner in the laser-treated side. Conclusion: A 1,450‑nm laser boosting treatment can help reduce pain and discomfort during early stages after thread lifting and improve elasticity, skin tone, sagging of mouth corners, jawline sagging, and overall patient satisfaction. Laser boosting treatment should be actively considered during thread lift to improve sagging of the mouth corner and jawline. Background: Polydioxanone used in thread lifting is mostly absorbed in skin tissues within six months, and its therapeutic effect diminishes gradually. However, we often experience a decrease in the effectiveness of thread lifting within 1–2 months. We performed a laser boosting treatment to maintain the long-term effect of thread lifting and reported its additional utility. Objective: To investigated the impact of laser boosting treatment on therapeutic effect and patient satisfaction after thread lifting during the first three months. Methods: This study was conducted between March and July, 2019. Severity of jawline and mouth corner sagging were graded by Merz Scale scores in seven middle-aged female patients. After the symmetrical thread lift procedure, 1,450-nm laser boosting treatment was applied to the side of the face with higher preoperative grade. Average pain scores at postoperative day (POD) 0, 3, and 7 were compared, including changes from POD 0 to POD 3 and 7. Face halves were compared regarding improvements in elasticity, skin tone, sagging of mouth corners, jawline sagging, overall satisfaction, and Merz Scale scores after three months. Results: All the patients showed improvements in elasticity, skin tone, sagging of mouth corners, and jawline sagging with improved overall patient satisfaction. During pain assessment, five of the seven patients showed greater changes in the laser-treated side at POD 3 and 7. Comparing the Merz Scale scores, there was a significant difference between pre- and post-treatment in jawline sagging and between jawline sagging and sagging of mouth corner in the laser-treated side. Conclusion: A 1,450‑nm laser boosting treatment can help reduce pain and discomfort during early stages after thread lifting and improve elasticity, skin tone, sagging of mouth corners, jawline sagging, and overall patient satisfaction. Laser boosting treatment should be actively considered during thread lift to improve sagging of the mouth corner and jawline.

Interaction of Laser Beam with PZT - Target and Observation of Laser - Induced Plume and Particle Ejection

이병우,Lee, Byeong-U Korean Society of Marine Engineers 1996 한국마린엔지니어링학회지 Vol.20 No.5

Laser-induced plume and laser-target interaction during pulsed laser deposition are demonstrated for a lead zirconate titanate (PZT). A KrF excimer laser (wavelength 248nm) was used and the laser was pulsed at 20Hz, with nominal pulse width of 20ns. The laser fluence was~$16J/cm^2,$ with 100mJ per pulse. The laser-induced plasma plume for nanosecond laser irradiation on PZT target has been investigated by optical emission spectra using an optical multichannel analyzer(OMA) and by direct observation of the plume using an ICCD high speed photography. OMA analysis showed two distinct ionic species with different expansion velocities of fast or slow according to their ionization states. The ion velocity of the front surface of the developing plume was about $10^7$cm/sec and corresponding kinetic energy was about 100eV. ICCD photograph showed another kind of even slower moving particles ejected from the target. These particles considered expelled molten parts of the target. SEM morphologies of the laser irradiated targets showed drastic melting and material removal by the laser pulse, and also showed the evidence of the molten particle ejection. The physics of the plasma(plume) formation and particle ejection has been discussed.