• Korean Journal of Bronchoesophagology
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• v.2 no.1
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• pp.135-139
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• 1996

Laryngeal amyloidosis is a rare benign disease. It is characterized by extracellular deposition of homogeneous and eosinophilic protein material in the form of fibrils. Diagnosis of this disease is made by histologic examination of involved tissue. It is ususlly primary or localized but rarely associated with a systemic or generalized disease. We present a case of primary laryngeal amyloidosis that was treated with KTP 532 laser vaporization.

• Korean Journal of Head & Neck Oncology
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• v.24 no.2
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• pp.139-144
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• 2008

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.26 no.1
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• pp.54-57
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• 2015

Hemangioma is one of the most common benign neoplasm, which occurs about 50% in head and neck region, but laryngeal hemangioma is relatively rare. Hemangioma occurred in larynx can be treated by surgical removal, cryosurgery, and steroid injection. Transoral CO2 laser micorsurgery has been known as useful method for the treatment of laryngeal hemangioma. We have experienced a 54-years old male patient of hemangioma originated in arytenoid area. This mass was removed via transoral approach with 'en bloc' resection by CO2 laser. We report this case regarding the treatment and prognosis of laryngeal hemangioma with review of literatures.

• Korean Journal of Head & Neck Oncology
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• v.19 no.1
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• pp.21-24
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• 2003

Objectives: In this report, we confirmed the distributed pattern of ALA and ALA-methylester in normal and tumor-bearing region. Materials and Methods: ALA and ALA-methylester were administered to nude mouse by intratumoral, subcutaneous and intravenous injection. After injection, the fluorescence in normal and tumor region was measured by LESA (laser electronic spectrum analyzer). Results: The tumor-specificity of ALA and ALA-methylester was shown in the case of intratumoral injection. In all case, the fluorescence caused by ALA and ALA-methylester was maximally increased in 2 hours after injection. Then while the fluorescence level was rapidly decreased to control level in normal region, it was still remained in tumor region. Conclusion: According to this result, The intratumoral injection was more efficient administration method for PDT/PDD than subcutaneous and intravenous injection.

• Korean Journal of Head & Neck Oncology
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• v.17 no.1
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• pp.3-7
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• 2001

Objectives: New photosensitizer 9-hydroxypheophorbide-$\alpha$(9-HpbD-$\alpha$) was derived from chlorophyll in water with peak absorption at 660nm. 9-HpbD-$\alpha$ was tested with 660 nm diode laser for the anticancer effect of photodynamic therapy. Materials and Methods: Human SNU 1041 cells were seeded into 96 well plate at a density of $$ cells/well for 24 hours. Cells were washed with media containing various concentration of 9-HpbD-$\alpha$ ranging from $0{\mu}g/ml\;to\;3.75{\mu}g/ml$. Then, laser treatment was done with 660nm diode laser ($10mW/cm^2$) at various time setting (0, 30, 60, 90, 120 minutes) and with various time interval (0, 1, 4, 6, 18 hours). The treated cells were incubated 48 hours and MTT assay was done to measure the viability of cells. Results: The viability of cells was more than 90% after laser treatment in control group. The viability of cells was decreased with increasing concentration of 9-HpbD-$\alpha$ and laser treatment time in experimental groups. The viability of cells was decreased significantly as the interval time between addition of 9-HpbD-$\alpha$ and laser irradiation was increased. Conclusion: This study shows the anticancer effect of photodynamic therapy using 9-HpbD-$\alpha$ and 660nm Diode laser on carcinoma cell line. 9-HpbD-$\alpha$ is considerd as one of new photo sensitizers in the field of photodynamic therapy.

• Korean Journal of Bronchoesophagology
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• v.17 no.1
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• pp.29-34
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• 2011

Traditionally, the main strategy of treatment of the head and neck cancer was en bloc resection including adjacent normal tissues through wide incision. However, the procedures may leave severe functional deficit such as swallowing difficulty, aspiration, and wide neck scar. Therefore, many attempts have been made up to minimize these morbidities. Of them, the minimal invasive approach such as transoral laser microsurgery (TLM) and transoral robot surgery (TORS) have been spolighted as a sensible strategy for organ preservation of the head and neck cancer patients. Results of TLM are equivalent to those obtained by conventional surgery, with considerably less morbidity, less hospital time and better postoperative function. Oncologic results of TLM are equivalent to conventional surgery. TORS are safe, feasible, and promising but oncologic safety is not yet verified. This article covers to current application of TLM and TORS, their advantages and limitations, and future direction.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.2
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• pp.61-67
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• 1998

Dynamic stability in rotation of the head drum of digital VCR is very important due to the nature of high rotation speed and small angular inertia. Therefore special considerations on reducing the unbalance and assuring the stability are required the design and manufacturing process. In this paper, newly developed digital head drum is introduced. And advanced methods in analyzing and reducing the unbalance is suggested. LDV(Laser Doppler Vibrometer) was used as a measurement system verifying our modeling and new method for balancing. Experiments show that the theoretical data estimated by modeling of shaft bending caused by unbalance mass and the measured data are almost identical. The deflection was reduced to 30％ by applying the suggested balancing method.

• Journal of Institute of Convergence Technology
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• v.3 no.2
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• pp.31-37
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• 2013

This paper proposes a vision-based inspection algorithm for a punch which is used when forming the head of the small screws. To maintain good quality of punch, the precise inspection of its dimension and the depth of the punch head is important. A CCD camera and an illumination dome light are used to measure its dimensions. And a structured line laser is also used to measure the depth of the punch head. Resolution and visible area depend on setup between laser and camera which is determined using CAD-based simulation. The proposed method is successfully evaluated using experiment on #2 punch.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.31 no.2
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• pp.92-95
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• 2020

Tracheal granuloma, the most commonly reported sequela of pediatric tracheotomy. A variety of techniques are available for the management of tracheal granuloma. Potassium-titanyl-phosphate (KTP) laser has been previously established as an acceptable technique for removal of laryngeal surgery, which emits a green light with a wave length of 532 nm, which is well-absorbed by hemoglobin and can coagulate and vaporize tissue. The ability to deliver laser energy through a flexible glass fiber makes the technique convenient for use with a rigid bronchoscope, overcoming problems with intraluminal access encountered with earlier attempts at CO2 laser therapy for this problem. Another advantage of KTP laser is the avoidance of the risks and morbidity associated with an open procedure. We report our surgical technique KTP laser in the management of tracheal granuloma removal into the tracheostomy site. KTP laser is good tool for management of tracheal granuloma with low incidence of complications.

• Korean Journal of Head & Neck Oncology
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• v.14 no.2
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• pp.164-168
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• 1998

Background: Supraglottis and glottis have a different embryologic origin. Supraglottic cancer is characterized by high incidence of cervical lymph node metastasis at initial diagnosis, and favored surgical management of the early supraglottic cancer was partial supraglottic laryngectomy, however the procedure resulted in frequent incidences of postsurgical aspiration and voice disabilities. Objectives: We retrospectively analyzed the problems and the advantages of the endoscopic laser assisted supraglottic partial laryngectomy as a part of surgical management for early supraglottic cancer. Materials and Methods: During the past nine years 25 cases of supraglottic cancer(Tl 10 cases, T2 15 cases) were treated by tracheotomy and laser assisted supraglottic partial laryngectomy(KTP532, 15 Watt, continuous type) and in 10 cases with cervical lymph node metastasis, they were additionally managed by neck dissection one week later, and all cases received postoperative irradiation therapy. Results: At present, 19 cases are alive with no evidence of disease. During the follow up period total of six cases(primary failure: three cases, nodal failure: three cases) were recurred. In relation to tumor staging, One of the 10 Tl cases and two of the 15 T2 cases recurred showing 88% locoregional recurrence rate for early supraglottic cancer. Postoperative com-plication included bleeding in three cases who were controlled by electrocautery under general anesthsia, one case of longstanding aspiration and two cases of laryngeal stenosis as a delayed complication. Conclusion: High control rate suggests that the endoscopic laser assisted supraglottic partial laryngectomy may be a good initial management method for early supraglottic cancer, however it is difficult to determine the resection margin, therefore, accurate tumor staging must be done prior to surgery. In order to prepare for postoperative bleeding, edema and aspiration, the tracheotomy must be performed prior to surgery.