• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.9 no.1
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• pp.66-70
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• 1998

Background and Objectives : The managements of unilateral vocal cord palsy include type Ⅰ thyroplasty and arytenoid adduction. One type operation has been shown no satisfactory effect. We evaluated preoperative and postoperative speech of unilateral vocal cord palsy patients who received combined operation of type Ⅰ thyroplasty and arytenoid adduction to help for the management plan of unilateral vocal cord palsy patients. Materials and Methods : We reviewed the postoperative results and complication of 17 surgically treated patients of unilateral vocal cord palsy at Severance hospital from Nov. 1996 to Dec. 1997 retrospectively. They were received combined operation of type Ⅰ thyroplasty and arytenoid adduction. Their pre and post-operative speech were analyzed with MDVP(Multi-Dimension-Voice analysis Program) of CSL(Computerized Speech Lab). Results : After the operation, MPT(Maximal Phonation Time) was increased and MFR(Mean Flow Rate) was decreased in all patients. NHR(Noise to Harmonic Ratio) and VTI(Voice Turbulence Index) were decreased : liner, RAP(Relative Average Perturbation Quotient), PPQ(Pitch Period Perturbation Quotient), sPPQ(smoothed Pitch Period Perturbation Quotient), vFo(fundamental frequency Variation) were decreased : Shimmer, APQ(Amplitude Perturbation Quotient), sAPQ(Smoothed Amplitude Perturbation Qoutient), vAm(Peak Amplitude Variation) were decreased in all the patients. Conclusions : In unilateral vocal cord pals), combined operation of type Ⅰ thyroplasty and arytenoid adduction could obtain satisfactory postoperative voice. MDVP has many parameters and good method for evaluation of voice surgery.

• Korean Journal of Bronchoesophagology
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• v.17 no.1
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• pp.53-56
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• 2011

Vocal cord paralysis (VCP) is a common complication after thyroidectomy despite the continuity of the recurrent laryngeal nerve (RLN) is preserved. Much efforts have been made into preventing VCP, but few of them focuses on the treatment strategies and prognosis after VCP take place. In this case, patient visited the clinic for papillary thyroid cancer in Rt. thyroid gland without VCP. She underwent total thyroidectomy with central neck dissection. During dissection, Rt main mass was encircling Rt. RLN. To make matters worse, Lt. RLN was severed due to tight attachment with Berry's ligament. After that, intratumoural dissection of Rt. RLN and end to end anastomosis of Lt. RLN were performed with microscopy to preserve the functions of RLNs as much as possible, otherwise permanent bilateral VCPs were inevitable. We report this case, since both vocal cords recovered from VCPs with symmetric, synchronous movements at postoperative follow up.

• International journal of thyroidology
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• v.11 no.2
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• pp.130-136
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• 2018

Background and Objectives: Intraoperative neural monitoring (IONM) of recurrent laryngeal nerve (RLN) in thyroid surgery has been employed worldwide to identify and preserve the nerve as an adjunct to visual identification. The aims of this study was to evaluate the efficacy of IONM and difficulties in the learning curve. Materials and Methods: We studied 63 patients who underwent thyroidectomy with IONM during last 2 years. The standard IONM procedure was performed using NIM 3.0 or C2 Nerve Monitoring System. Patients were divided into two chronological groups based on the success rate of IONM (33 cases in the early period and 30 cases in the late period), and the outcomes were compared between the two groups. Results: Of 63 patients, 32 underwent total thyroidectomy and 31 thyroid lobectomy. Failure of IONM occurred in 9 cases: 8 cases in the early period and 1 case in the late period. Loss of signal occurred in 8 nerves of 82 nerves at risk. The positive predictive value increased from 16.7% in the early period to 50% in the late period. The mean amplitude of the late period was higher than that of the early period (p<0.001). Conclusion: IONM in thyroid surgery is effective to preserve the RLN and to predict postoperative nerve function. However, failure of IONM and high false positive rate can occur in the learning curve, and the learning curve was about 30 cases based on the results of this study.

• International journal of thyroidology
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• v.11 no.2
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• pp.109-116
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• 2018

It is very important to identify recurrent laryngeal nerve (RLN) and prevent RLN injury during thyroid surgery. The intraoperative neuromonitoring (IONM) for the prevention of RLN injury is a useful method because it can identify the location and status of RLN and predict postoperative vocal cord function easily. The IONM consists of a stimulating side that applies electrical stimulation to the nerve and a recording side that measures the surface electromyography (EMG) of the vocal cord muscle through electrode endotracheal tube. The nerve stimulator and surgical dissector are separate instruments. So, during IONM for the prevention of the RLN injury in conventional, endoscopic, or robotic thyroid surgery, repeated exchanging between surgical instruments and the nerve stimulator is inconvenient and time consuming. On the recording side, the accuracy of the electrode endotracheal tube which measures the EMG of the vocalis muscle can be affected by contact with between electrode and vocal fold and position change of patient. We would like to introduce recent several researches to overcome the current limitations of IONM.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1979.05a
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• pp.6.3-7
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• 1979

During last two. decades, microlaryngeal surgery opened now era in the laryngeal surgery. In 1960, using Lynch's suspension laryngoscope, Seal co et al performed the first successful microsurgery in the treatment of polyp and other laryngeal diseases. In 1968, Kleinsasser reported a new technique of microlaryngeal surgery with a self retaining laryngoscope. Authors studied the statistic analysis of 53 cases (75 times) of the suspension laryngoscopic microsurgery at E.N.T. department of Han Yang University Hospital from May 1972 to April 1979 an reported this result. 1) sex distribution was male 1.3 : female 1. 2) age distribution was 3rd decade 14 cases (26.4%), 2nd decade 10 cases (18.7%) and 5th decade 9 cases (17%) in order. 3) chief compliant was hoarseness 48 cases (90.6%), dyspnea 16 cases (30.5%) and sore throat 8 cases (15.1%) in order. 4) diagnostic impression was polyp 18 cases (34%), nodule 12 cases (22.6%), papilloma 9 cases (17%), tumor 7 cases (13.2%), intubation granuloma 3 cases (5.7%) in order and other kinds were laryngeal stenosis with decannulation difficulty, laryngeal paralysis and hematoma. 5) histopathologic result of 48 cases was polyp 17 cases (35.4%), papilloma 11 cases (23%), nodule 9 cases (18.9%), malignancy 3 cases (6.3%), chronic inflammation 2 cases (4.2%) in order and others were hyperkeratosis, mucous retension cyst, nodule associated abscess, granuloma, hematoma and unconfirmed case. 6) in involved site, both sides 15 cases (60%), Lt.side 5 cases (19%), Rt side 3 cases (12%), anterior commissure 3 cases (12%) on the nodule and polyp (26 cases) and whole laryngeal involvement 7 cases (63.6%), one side cord involement 3 cases (23.7%), extralaryngeal involvement 1 cases (9.1%) on the papilloma (11 cases).

• Phonetics and Speech Sciences
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• v.12 no.2
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• pp.73-80
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• 2020

Breathing is the voice's driving force and also acts as a regulator of larynx function and efficiency. Respiratory distress is a side effect of general anesthesia in thyroid surgery. Therefore, this study's objective was to provide practical and complementary information for voice recovery after thyroid surgery, based on aerodynamic evaluation pre- and post-thyroidectomy. From May 2014 to July 2015, aerodynamic evaluations were performed on 34 female patients diagnosed with thyroid papillary cancer one week before surgery (PRE), one month after surgery (P1), and three months after surgery (P3). The Phonatory Aerodynamic System (model 6600, KayPENTAX, USA) was employed for this purpose, and a total of 29 analysis parameters were selected. The results showed statistically significant differences in peak expiratory airflow (p=0.004), mean pitch (p<0.01), expiration airflow duration (p=0.001), and expiratory volume (p=0.018), based on time factors. In the comparison of time factors, peak expiratory airflow and mean pitch parameters were different in PRE-P1 and PRE-P3. Expiration airflow duration and expiratory volume parameters were different in PRE-P3 and P1-P3. The interaction effect of time and surgical range was significant only for expiratory volume (p=0.024). Female patients who undergo thyroidectomy require post-operative breathing training, and exhalation improvement is considered to reflect a positive lifestyle after surgery.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.14 no.2
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• pp.117-122
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• 2003

Background and Objectives : $VoCoM^{\circledR}$ is a commercialized set composed of prefabricated hydroxylapatite implants and shims of various sizes which are specially designed for the type I thyroplasty. Even though a previously published preliminary report showed that $VoCoM^{\circledR}$ is a convenient and safe product for the type I thyroplasty, further investigations or experiences are yet to be reported. Authors aimed to evaluate the efficacy of $VoCoM^{\circledR}$type I thyroplasty, and its advantage and/or disadvantage. Materials and Method : Twenty three consecutive patients with unilateral vocal cord palsy enrolled for the study, who received type I thyroplasty with $VoCoM^{\circledR}$ between July 2001 and June 2003. Acoustic, aerodynamic and stoboscopic analyses were performed prior to surgery and 1 to 3 months after surgery. Speech language pathologists evaluated their voice quality by GRBAS scale, and patients themselves reported subjective changes of their voice by visual analog scale. Results : The average time for the operation was 80 min, which is about 30 min less than other methods. Preoperative jitter was 3.25$\pm$1.65% and improved to 1.94$\pm$1.79% postoperatively (p<0.05). Preoperative shimmer was 9.72$\pm$6.56% and improved to 5.61 $\pm$3.76% (p<0.05), Maximal phonation time increased from 4.41$\pm$2.99 to 7.98$\pm$4.35 sec (p<0.05) The postoperative stroboscopy revealed an effective medialization in 91.3% of the patients. The subjective phonetic improvements were reported in 21 out of 23 patients. GRBAS scale improved from 2.71$\pm$0.46 to 1.47$\pm$1.12(p<0.05). Additional medialization with $Gore-Tex^{\circledR}$ was easily performed in two revision cases. Previously inserted $VoCoM^{\circledR}$ implant was hard to remove because of the tight integration of soft tissues around the implant. Side effects such as extrusion or foreign body reaction are not observed. $VoCoM^{\circledR}$ was relatively expensive and costed more than 10 times of $Gore-Tex^{\circledR}$. Conclusion : Prefabricated hydroxylapatitie implant($VoCoM^{\circledR}$) provides a convenient, safe and efficient way of vocal fold medialization. However it is relatively expensive and hard to remove.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.675-680
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• 2010

Background: The aim of this study was to identify the distinguishing clinicoradiologic findings of traumatic tracheobronchial injury. Material and Method: Between January 2003 and December 2009, six patients who underwent surgical repair for traumatic tracheobronchial injury due to blunt trauma were included in this study. We evaluated the mechanism of the injury, the coexisting injuries, the time until the making diagnosis and treatment, the diagnostic methods, the anatomic location of the injury and the surgical outcomes. Result: The mechanisms of injury were traffic accident and crushing forces. The frequent symptoms were subcutaneous emphysema, dyspnea and pain, and the common radiologic findings were pneumothorax, mediastinal emphysema, rib fracture and lung contusion. Only 2 patients were diagnosed by chest CT and the others were not diagnosed preoperatively. The location of injury was the trachea in 2 patients and the bronchial tree in 4 patients. There was no postoperative mortality or anastomotic leak; however, vocal cord palsy occurred in one patient. The most distinguishing sign was persistent lung collapse even though the chest tube was connected with negative pressure. Conclusion: Although it was not easy to diagnose traumatic tracheobronchial injury without a clinical suspicion, the distinguishing clinical symptoms and CT findings could help to make an early diagnosis without performing bronchoscopy.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.04a
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• pp.16-16
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• 2000

충격파를 포함하는 초음속 유동을 해석하는 수치해법 중에서 많이 사용되어진 것은 엄밀 및 근사 리만 해법과 플럭스 분할 기법들로서 이들은 Euler 방정식에 기반을 두고 선형 또는 비선형파의 상호작용을 풍상 차분법으로 기술하는 방법들이다. 이러한 수치기법들은 과거 광범위하게 사용되어 왔으나 최근 여러 가지 단점이 발견되었다. 이와 같은 문제점을 극복하고자 입자의 통계적인 운동을 기술하는 기체 운동론에 근거하여 BGK 수치기법이 제시되었다. 이는 비충돌 볼츠만 방정식으로부터 입자의 수준에서 플럭스 분할 기법 형태의 풍상차분법을 구현하는 것으로 볼츠만 방정식의 충돌항을 BGK 모델로 대치하고 이것의 적분해로부터 수치 플럭스를 구한다. 이 수치기법은 기존의 리만해법에 비하여 수치적으로나 물리적으로 매우 타당한 성질인 강건성, 정확성, 엔트로피 조건, 양수보존성 등을 가지고 있음이 밝혀졌다. 이와 같은 수치기법을 사용하여 로켓 노즐 내의 아음속, 천이음속, 초음속에서의 유동장 해석을 위한 프로그램을 작성하였다. 시간 적분에 대하여는 정상 상태의 계산을 위하여 내재적 시간 적분 방법을 사용하였으며, 공간 이산화 방법으로는 임의의 제어체적에 대하여 적분형 보존 방정식을 적용하는 유한 체적법을 사용하였다. 초음속 입구 유동과 출구에서 초음속과 저음속 유동의 두가지 경우를 고려하여 얻은 결과를 기존의 연구 결과와 비교하여 본 결과 잘 일치하였다. 입구 유동이 저음속이고 출구 유동이 초음속인 경우에 대하여도 해석결과가 실험결과와 잘 일치하였다. 상대적으로 낮은 온도, 압력 조건과 높은 온도, 압력 조건을 가지는 고체 로켓 모터 노즐 내의 유동을 해석하였다. 이들 해석 결과를 전압, 전온도로 표준화시킨 결과 서로 일치하였으며, 파라서 저온, 저압에서 얻은 결과도 표준화시킬 경우, 고온, 고압에서도 사용될 수 있음을 알 수 있었다.의 영향에 초점을 맞추었다.다고 판단되며 배기 가스 자체에 대기 공기중에 함유되어 있던 습기가 얼어붙는(Icing화) 문제가 발생하기 때문에 배기가스의 Icing을 방지하기 위하여 압축기 끝단에서 공기를 추출하여 배기부분에 송출할 필요성이 있는 것으로 판단되었다. 출구가스의 기체 유동속도가 매우 빠르므로 (100-l10m.sec) 이를 완화하기 위한 디퓨저의 설계가 요구된다고 판단된다. 또 연소기 후방에 물을 주입하는 경우 열교환기 및 기타 부분품에 발생할 수 있는 부식 및 열교환 효율 저하도 간과할 수 없는 문제로 파악되었다. 이러한 기술적 문제가 적절히 해결되는 경우 비활성 가스 제너레이터는 민수용으로는 대형 빌딩, 산림, 유조선 등의 화재에 매우 적절히 사용되어 질 수 있을 뿐 아니라 군사적으로도 군사작전 중 및 공군 기지의 화재 그리고 지하벙커에 설치되어 있는 고급 첨단 군사 장비 등의 화재 뿐 아니라 대간첩작전 등에 효과적으로 활용될 수 있을 것으로 판단된다.가 작으며, 본 연소관에 충전된 RDX/AP계 추진제의 경우 추진제의 습기투과에 의한 추진제 물성 변화는 미미한 것으로 나타났다.의 향상으로, 음성개선에 효과적이라고 사료되었으며, 이 방법이 편측 성대마비 환자의 효과적인 음성개선의 치료방법의 하나로 응용될 수 있으리라 생각된다..7%), 혈액투석, 식도부분절제술 및 위루술·위회장문합술을 시행한 경우가 각 1례(2.9%)씩이었다. 13) 심각한 합병증은 9례(26.5%)에서 보였는데 그중 식도협착증이 6례(17.6%), 급성신부전증 1례(2.9%), 종격동기흉과 폐염이 병발한 경우와 폐염이 각 1례(2.9%)였다. 14) 식도경 시행회수는 1회가 17례(54.8%), 2회가 9례(29.0%), 3회 이상이 5례(16.1%)였다.EX>$IC_{50}$/ 값이 210 $\mu\textrm{g}$<

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.04a
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• pp.10-10
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• 2000

램제트 엔진은 비추력이 높고 추력 레벨은 낮으므로, 2단 추진기관에 적합한 추진 시스템이다. 1단-추진기관의 작동이 끝나고, 2단 램제트 엔진이 점화 후 안정된 연소에 도달되기까지 비행체의 속도는 항력에 의하여, 초당 약 마하수 0.1 정도씩 감소된다. 1단 연소 후 2단 램제트로 전환되는 지연시간이 길수록 1단에서 요구되는 종말 가속도는 증가되므로, 1단이 차지하게되는 부피는 증가되고 비행체의 크기 또한 늘어나게 된다. 따라서 1단에서 2단 램제트로 천이되는데 소요되는 시간을 가능한 짧게 하는 것이 효과적이다. 그러나 램제트 엔진의 특성상 선결되어야할 다음과 같은 여러 문제들이 있다. 첫째, 1단 작동 시 공기 흡입구와 연소실은 차단벽으로 분리되어 있다가, 1단 연소후 차단막이 제거되어 외부공기가 램제트 연소실로 흡입된다. 흡입되는 공기는 흡입구의 형상에 의하여 램 압축되지만 초음속으로 연소실을 통과하게된다. 연료 주입 구에서 공급되는 연료는 연소실에서 유동의 흐름방향(streamline)에 따라서 연소실로 확산되는데, 연소되기 전에는 유속이 빠르게 노즐로 빠져 나가므로 램제트 연료가 재순환 구역(recirculation zone)으로 침투하는데 쉽지가 않다. 둘째, 연소실 입구에서 발생되는 와류 (ring vortex)는 1단 연료의 고온 연소 가스를 연소실로 확산시키는데, 비 균일한 온도 분포를 유발하여 램제트 연료의 점화에너지가 공급되는 시간이 적당하지 않을 경우 균일한 화염 전파에 악영향을 준다. 셋째, 연소실에서의 빠른 유동 조건은 연료가 연소실에 머무를 수 있는 시간을 감소시키며, 연소실 입구에서 강한 전단 응력이 발생되어 화염이 안정화되는데 악 영향을 미치게된다. 본 논문은 공기 흡입구, 연소실 및 노즐을 통합하여 수치해석을 하였으며 열유동/점화/연소등의 미케니즘을 이해하고, 주요 인자들 중 와류의 영향에 초점을 맞추었다.다고 판단되며 배기 가스 자체에 대기 공기중에 함유되어 있던 습기가 얼어붙는(Icing화) 문제가 발생하기 때문에 배기가스의 Icing을 방지하기 위하여 압축기 끝단에서 공기를 추출하여 배기부분에 송출할 필요성이 있는 것으로 판단되었다. 출구가스의 기체 유동속도가 매우 빠르므로 (100-l10m.sec) 이를 완화하기 위한 디퓨저의 설계가 요구된다고 판단된다. 또 연소기 후방에 물을 주입하는 경우 열교환기 및 기타 부분품에 발생할 수 있는 부식 및 열교환 효율 저하도 간과할 수 없는 문제로 파악되었다. 이러한 기술적 문제가 적절히 해결되는 경우 비활성 가스 제너레이터는 민수용으로는 대형 빌딩, 산림, 유조선 등의 화재에 매우 적절히 사용되어 질 수 있을 뿐 아니라 군사적으로도 군사작전 중 및 공군 기지의 화재 그리고 지하벙커에 설치되어 있는 고급 첨단 군사 장비 등의 화재 뿐 아니라 대간첩작전 등에 효과적으로 활용될 수 있을 것으로 판단된다.가 작으며, 본 연소관에 충전된 RDX/AP계 추진제의 경우 추진제의 습기투과에 의한 추진제 물성 변화는 미미한 것으로 나타났다.의 향상으로, 음성개선에 효과적이라고 사료되었으며, 이 방법이 편측 성대마비 환자의 효과적인 음성개선의 치료방법의 하나로 응용될 수 있으리라 생각된다..7%), 혈액투석, 식도부분절제술 및 위루술·위회장문합술을 시행한 경우가 각 1례(2.9%)씩이었다. 13) 심각한 합병증은 9례(26.5%)에서 보였는데 그중 식도협착증이 6례(17.6%), 급성신부전증 1례(2.9%), 종격동기흉과 폐염이 병발한 경우와 폐염이 각 1례(2.9%)였다. 14) 식도경 시행회수는 1회가 17례(54.8%), 2회가 9례(29.0%), 3회 이상이 5례(16.1%)였다.EX>$IC_{50}$/ 값이 210 $\mu\textrm{g}$/$m\ell$로서 효과적