The effect of electromagnetic guidance system on early learning curve of ultrasound for novices

변효진,김은정,민지영,송정윤,송경철,송장호 대한마취통증의학회 2016 Korean Journal of Anesthesiology Vol.69 No.1

Background: Electromagnetic guidance reveals needle alignment and position relative to the image plane on an ultrasound view. This study compared the early learning curves of novices performing ultrasound-guided needle placement with (n = 10) or without electromagnetic guidance (n = 10). Methods: Participants performed 30 ultrasound-guided needle placements using an echogenic stick (0.3-cm diameter) as a target inside a phantom model; this early learning period was divided into sequential periods (P1: 1–5, P2: 6–10, P3: 11–15, P4: 16–20, P5: 21–25, P6: 26–30 attempts). Results: Using an in-plane approach, the time required for needle placement in the EMG group was significantly shorter than that of the non-EMG group in P1, P2, P4, and P6 and the number of needle advances of the EMG group was significantly smaller than that of the non-EMG group in P1 and P2. Using an out-of-plane approaches, the time required for needle placement in the EMG group was significantly shorter than that of the non-EMG group in all periods, but the number of needle advances was similar between both groups in P1–P5. Conclusions: The electromagnetic guidance system may be beneficial when performing ultrasound guided peripheral nerve blocks or vascular cannulation in the early learning period, especially by inexperienced operators with reducing patient risk.

The influence of DNA polymorphism of multidrug resistant 1 (MDR1) on the effect of midazolam pretreatment in children

변효진,박근석,박용희,김진태,정철우,김희수 대한마취통증의학회 2012 Korean Journal of Anesthesiology Vol.62 No.4

Background: Patients showed a different response following intravenous midazolam injection. Some children showed irritability or were not sedated by midazolam. We hypothesized that there may be genetic variations of the MDR1 gene, based on the response to midazolam. Methods: One hundred and ninety-three pediatric patients were recruited in this study. Midazolam (0.1 mg/kg) was injected intravenously before surgery. Anxiety score (activity, vocalizations, emotional expressivity, state of apparent arousal) was checked before and 5 minutes after midazolam injection. In addition, other manifestations after midazolam injection were recorded. After anesthesia, 2 ml of blood was sampled. Children were genotyped MDR1. Haplotype was analyzed using the software package PHASE, version 2.0. Results: The observed frequencies of MDR1 haplotype of TTT, TGC, CAC, CGC were 0.334, 0.205, 0.182 and 0.225, respectively. There was no significant correlation between the response of midazolam and the MDR1 haplotype of TTT, TGC, CAC or CGC (P = 0. 98). Conclusions: Genotyping of MDR1 may not be related to the response of midazolam in children.

Comparison of the preventive effects of pretreatment of lidocaine with a tourniquet and a premixed injection of lidocaine on propofol-LCT/MCT injection pain

변효진,이길우,심영희,정종권,차영덕,이두익,송장호 대한마취통증의학회 2014 Korean Journal of Anesthesiology Vol.66 No.2

Background: Lidocaine has been used widely to prevent propofol injection pain. Various methods of administration exist, such as lidocaine premixed with propofol or lidocaine pretreatment using a tourniquet, but it is unclear which method of lidocaine administration is more effective for the prevention of injection pain of propofol LCT/MCT. The purpose of this study was to compare pretreatment of lidocaine with a tourniquet and a premixed injection of lidocaine to prevent injection pain of propofol-LCT/MCT. Methods: Patients were randomly allocated into the pretreatment group (n = 117) or the premixed group (n = 117). The pretreatment group was pretreated with 2 ml of lidocaine 2%, held with a tourniquet, before propofol-LCT/MCT injection. The premixed group was injected with a premixed solution of propofol-LCT/MCT and 2 ml of lidocaine 2%. To evaluate the incidence and severity of pain, spontaneous verbal expressions of pain, movement of hand, frowning, and moaning were recorded, and the patients were asked to recall their pain with the visual analogue score (VAS) 30 minutes after awakening from anesthesia. Results: Overall, injection pain occurred in 13.7% of the pretreatment group and 15.4% of the premixed group, without any statistical difference (P = 0.71). There was no difference in spontaneous verbal expressions of pain, movement of hand, frowning, and moaning between the two groups. The pain intensity (VAS) also showed no difference between the two groups (P = 0.49). Conclusions: Pretreatment of lidocaine with a tourniquet showed no more benefit to prevent injection pain of propofol LCT/MCT compared to a premixed injection with lidocaine.

전정맥마취와 흡입마취하에서 실시한 복강경 담낭절제술 시 심전도상 QTc 간격 변화의 비교

변효진,정성진,정현준,안현수,이홍식,이춘수,송장호 대한마취통증의학회 2013 Anesthesia and pain medicine Vol.8 No.1

Background: There can be changes in the cardiac function during laparoscopic cholecystectomy. In this study, QTc interval changes were compared between total intravenous anesthesia (TIVA) group and inhalation anesthesia group during laparoscopic cholecystectomy. Methods: The study was conducted on adult patients, ages ranging from 20 to 65 years old, and classified as the American Society of Anesthesiologists physical status I or II. At random, the patients were divided into group 1 (TIVA, n = 20) and group 2(inhalation anesthesia, n = 19). Group 1 patients were induced and maintained with continuous infusion of remifentanil and propofol using a target controlled infusion device. Patients in group 2 were induced with sevoflurane and N2O using mask ventilation, and then anesthesia was maintained with sevoflurane and N2O. The QTc interval, heart rate and mean arterial pressure were measured prior to induction, immediately following intubation, 10 minutes following intubation, following CO2 inflation, immediately following head-up position, 10 minutes following head-up position, following CO2deflation-supine position respectively. Results: In group 1, the ECG sampling showed no prolongation in the QTc intervals at all measured points. In group 2, QTc interval was significantly longer at all other measured points compared to prior to induction (P < 0.05). Except prior to induction, QTc intervals were significantly longer at all other measure points in group 2compared to those in group 1 (P < 0.05). Conclusions: There was no QTc interval prolongation under the TIVA using propofol and remifentanil during laparoscopic cholecystectomy.

시간적 분해에 기반한 F0 궤적 모델에 관한 연구

변효진,김연준,오영환 한국음향학회 1999 韓國音響學會誌 Vol.18 No.8

본 논문에서는 음성합성의 억양 제어를 위한 새로운 F0 궤적 모델을 제안한다. 제안한 모델은 발성된 문장의 F0 궤적을 중첩가산되는 사건들로 분해하고, 각 사건들을 가우시안 종모양의 사건함수로 모델링한다. 그리고 제안한 모델을 위한 파라미터 추정 알고리즘을 제시한다. 제안한 모델은 특정한 음운론적 지식에 기반하지 않았으며, F0 궤적의 분석단계와 합성단계에 모두 사용 가능하다. 제안한 모델의 성능평가를 위해 다양한 장르에서 추출한 여러 형태의 500문장의 코퍼스를 구축하고, 이를 전문 아나운서에게 발성하게 하여 구축한 음성코퍼스로 실험한 결과, 원음성의 F0 궤적과 제안한 모델에 의해 합성된 F0 궤적의 평균 제곱 오류근이 7.87Hz이었다. This paper proposes a new F0 contour model for intonation control in speech synthesis. We assume that the F0 contour of an utterance can be described using a sequence of time-overlapping events, which determine the fluctuation of a given F0 contour, described by asymmetric Gaussian functions. In addition, We propose a parameter estimation algorithm for the proposed model. The proposed model is not developed with a particular phonological theory in mind, and can be used in both F0 contour analysis and synthesis. For testing our F0 model, we collected 500 sentences from various genres and built a corresponding speech corpus uttered by a professional female announcer. As n result of F0 resynthesis experiment using the proposed model, the RMSE was 7.87Hz for given speech corpus.

질의 - 응답 시스템에서의 의미정보를 이용한 음성생성에 관한 연구

변효진(Heo-Jin Byeon),오영환(Yung-Hwan Oh) 한국정보과학회 1995 한국정보과학회 학술발표논문집 Vol.22 No.1

본 논문에서는 질의-응답 시스템의 대화처리부에서 생성하는 의미정보를 이용하여 음성을 생성하는 방법을 제안한다. 음성합성부의 입력형태는 응답문장의 의미정보를 표현한 SM(Semantic Message)을 정의하여 사용하였다. 의미정보 형태에 따른 응답문형을 정의하고, 정의된 문형과 생성문장에 사용될 동사의 격구조를 이용하여 응답문장을 생성한다. 응답문장을 생성할 때 함께 생성되는 구문구조정보와 응답문형정보를 이용하여 생성음성의 길이, 세기, 억양등의 운율제어를 한다. 음성합성은 TD-PSOLA(Time Domain-Pitch Synchronous Overlap Add) 합성방식을 이용하였으며, 합성단위는 확장성과 조음현상을 고려하여 2-3개의 음운열(모음, 자음의 조합)을 이용하였다. 열차예약에 관련된 질의에 대한 응답생성을 실험하여, 제안된 방법에 의해 생성한 합성음을 MOS(Mean Opinion Score) 평가한 결과, 7.1/10의 평가점수를 얻었다.

미디어 기업의 사회적 책임 활동에 대한 이용자와 조직 구성원의 인식 차이 연구

변효진(Hyojin Byun),전범수(Bum Soo Chon) 한국방송학회 2008 한국방송학보 Vol.22 No.4

연속식 하수처리 공정에서의 슬러지를 이용한 바이오 가스 회수

양효진,변병수,양인석,전항배 대한환경공학회 2013 대한환경공학회 학술발표논문집 Vol.2013 No.6

중환자실 간호사의 감정노동과 직무만족도 관계에서 회복탄력성의 조절 및 매개효과

변미림,이윤미,박효진 한국중환자간호학회 2019 중환자간호학회지 Vol.12 No.3

Purpose : The purpose of this study was to identify the moderating and mediating effects of resilience in the relationship between emotional labor and job satisfaction among nurses working in intensive care units (ICUs). Method : The participants were 144 ICU nurses from three university hospitals. Data were collected using structured questionnaires and analyzed by t-test, ANOVA, Scheffé test, Pearson correlation coefficients, and multiple regression analysis, using SPSS 25.0. The mediating effect of resilience in the relationship between emotional labor and job satisfaction was analyzed by multiple regression analysis according to Baron and Kenny’s procedure. Results : Statistically significant negative correlations were found between emotional labor and resilience (r=-.21, p<.014) and between emotional labor and job satisfaction (r=-.34, p<.001). A significant positive correlation was found between resilience and job satisfaction (r=.31 p<.001). A partial mediating effect by resilience was found between emotional labor and job satisfaction (Z=-2.11, p = .034), but no moderating effect was found. Conclusion : To improve the job satisfaction of ICU nurses, evaluation of their emotional labor, resilience, and interventions are necessary to alleviate emotional labor and improve resilience.

Biophysical Effects Simulated by an Ocean General Circulation Model Coupled with a Biogeochemical Model in the Tropical Pacific

박효진,문병권,위지은,김기영,변영화 한국지구과학회 2017 韓國地球科學會誌 Vol.38 No.7

Controversy has surrounded the potential impacts of phytoplankton on the tropical climate, since climate models produce diverse behaviors in terms of the equatorial mean state and El Niño-Southern Oscillation (ENSO) amplitude. We explored biophysical impacts on the tropical ocean temperature using an ocean general circulation model coupled to a biogeochemistry model in which chlorophyll can modify solar attenuation and in turn feed back to ocean physics. Compared with a control model run excluding biophysical processes, our model with biogeochemistry showed that subsurface chlorophyll concentrations led to an increase in sea surface temperature (particularly in the western Pacific) via horizontal accumulation of heat contents. In the central Pacific, however, a mild cold anomaly appeared, accompanying the strengthened westward currents. The magnitude and skewness of ENSO were also modulated by biophysical feedbacks resulting from the chlorophyll affecting El Niño and La Niña in an asymmetric way. That is, El Niño conditions were intensified by the higher contribution of the second baroclinic mode to sea surface temperature anomalies, whereas La Niña conditions were slightly weakened by the absorption of shortwave radiation by phytoplankton. In our model experiments, the intensification of El Niño was more dominant than the dampening of La Niña, resulting in the amplification of ENSO and higher skewness.