다구찌 기법을 이용한 차량용 휠 베어링 진원도 최적화

조호선(Hosun CHO),유창범(Changbeom Yu),오병기(Byungki Oh) 한국자동차공학회 2018 한국자동차공학회 학술대회 및 전시회 Vol.2018 No.11

Radiological analysis of the position of epidural catheters in the thoracic epidural space

김문규,박세광,조호범,김상호,옥시영 대한마취통증의학회 2014 Korean Journal of Anesthesiology Vol.67 No.6

Case report : Canine distemper virus infection in a wild Korean raccoon dog

조아라,노윤석,이해범,조호성,임채웅,강석진,김하영,김종완,김범석 한국예방수의학회 2015 예방수의학회지 Vol.39 No.1

Abstract: A female wild raccoon dog was referred with a history of generalized seizure. Mild leukocytosis was noted onlaboratory tests. Gross lesions included nasal hemorrhage, hemothorax, and hemorrhage in the urinary bladder withhematuria. Microscopically, interstitial and purulent bacterial pneumonia was observed in the lungs. In the cerebellum,characteristic eosinophilic intracytoplasmic and intranuclear inclusion bodies were found in Purkinje cells, and severedemyelination was observed in the cerebellar white matter. Canine distemper virus (CDV) infection was suspected andconfirmed after detection of CDV nucleoprotein RNA in the cerebrum and the lungs by nested reverse transcriptionpolymerase chain reaction (RT-PCR) and reverse transcription loop-mediated isothermal amplification (RT-LAMP). Based onthe histopathological and molecular diagnostic findings, it was concluded that the raccoon dog was infected with CDV.

Cause of postoperative mortality in patients with end-stage renal disease

송상훈,Cho Chaeyeon,박선영,조호범,유재화,김문규,정지원,김상호 대한마취통증의학회 2022 Anesthesia and pain medicine Vol.17 No.2

Background: The number of patients with end-stage renal disease (ESRD) who are dependent on hemodialysis is increasing rapidly. As a result, more patients with ESRD need surgery. These patients have a significantly higher risk of postoperative death than those with normal kidney function. Therefore, this study analyzed the causes of postoperative mortality in ESRD patients undergoing surgery under general anesthesia and the risk factors for postoperative mortality.Methods: This retrospective analysis examined the mortality of ESRD patients, 20 to 80 years old, undergoing surgery under general anesthesia. We excluded patients who underwent cardiac, cancer, or emergency surgery or organ transplantation from the analysis. The primary outcome was the cause of postoperative 30-day mortality in ESRD patients. We also assessed the mortality rate and risk factors.Results: There were 2,459 eligible ESRD patients. When patients underwent multiple surgeries during the study period, only the last surgery was considered. In total, 167 patients died during the study period, including 65 within 30 days postoperatively. The cause of death was sepsis in 22 cases (33.8%) and a major cardiac event in 16 (24.6%). Atrial fibrillation, current angina, previous myocardial infarction, asthma, lower hemoglobin and albumin levels, and a larger intraoperative colloid volume were likely to increase mortality. Conclusions: Our study suggests that immunological issues have a significant role in the death of ESRD patients after general anesthesia.

The effect of dexmedetomidine sedation on patient and surgeon satisfaction during retinal surgery under sub-tenon’s anesthesia : a randomized controlled trial

유재화,김순임,조아나,이성진,선해정,조호범,이동련 대한마취통증의학회 2015 Korean Journal of Anesthesiology Vol.68 No.5

Background: The purpose of this study was to evaluate the effect of intraoperative dexmedetomidine sedation on patient’s and surgeon’s satisfaction during retinal surgery under sub-tenon’s anesthesia. Methods: Forty-four patients scheduled for elective retinal surgery under sub-tenon’s anesthesia were enrolled in this randomized controlled trial. The patients were divided into Dexmedetomidine (n = 22) and Control (n = 22) groups. Intravenous dexmedetomidine or 0.9% saline via infusion pump were administered continuously to the dexmedetomidine or control group, respectively. Ramsay sedation scale with a target level of 3–4 was used to assess adequacy of sedation. Perioperative pain, hemodynamic and respiratory data were collected, while satisfaction from patients and surgeon were assessed post-surgery using a 5-point satisfaction scale. Results: Patient and surgeon satisfaction was higher in the dexmedetomidine group (P < 0.001, P = 0.002, respectively). The pain associated with sub-tenon’s anesthesia and peripheral vitrectomy was lesser in the dexmedetomidine group than in the control group (P = 0.020). There was significant reduction of heart rate in the dexmedetomidine group (P = 0.001), but only one patient needed treatment with atropine. There was no respiratory effect on both groups. Conclusions: Dexmedetomidine sedation during retinal surgery improved satisfaction from both patient and surgeon without respiratory complication. It is a safe and preferable choice of sedation for retinal surgery.

Comparison of eye protection methods for corneal abrasion during general anesthesia

이세진,김순임,정진권,고은효,조아나,조호범,한유미 대한마취통증의학회 2016 Anesthesia and pain medicine Vol.11 No.1

Background: Corneal abrasion is one of the most common ophthalmic complications that occurs after general anesthesia. Although they can occur by direct contact with surgical drapes or masks, most occur as a result of the drying of the cornea exposed during general anesthesia due to a reduced amount of tear secretions, the loss of light reflex, or the loss of recognition of pain during the procedure. Thus, to prevent corneal abrasions during general anesthesia, proper eye protection is required. Methods: Seventy-two patients (144 eyes) were divided into four groups as follows: 1) control group: careful manual eye closure; 2) adhesive tape group: a bandage attached over the eyelid; 3) ointment group: eye ointment placed into the eye followed by eye closure; and 4) ointment and tape group: eye ointment placed into the eye followed by a bandage attached over the eyelid, with the patient subjected to both methods for each eye. The National Eye Institute (NEI) scale, conjunctiva hyperemia scale, tear break-up time, and Schmer test were conducted before and after operation. Results: No statistically significant difference was noted between groups regarding the NEI scale, conjunctiva hyperemia scale, tear break-up time, or Schirmer test. Conclusions: To prevent corneal abrasions in normal patients undergoing general anesthesia, eye taping, eye ointment appli- cation, or taping after eye ointment application will not significantly reduce the degree of corneal epithelial damage compared to manual eye closure.

암석 시편의 충격반향(공진주) 시험에 관한 고찰

조정우(Jung-woo Cho),임보성(Bo-sung Lim),조호범(Ho-bum Cho),전석원(Seokwon Jeon),하희상(Hee-sang Ha) 한국암반공학회 2007 터널과지하공간 Vol.17 No.2

충격반향기법은 특정 매질에 충격을 가하여 매질의 동적 물성을 측정할 수 있는 비파괴 시험법이다. 본 연구에서는 암석시편에 충격반향기법을 수행할 수 있는 시험장비를 설치하고, 동적 물성치를 측정할 수 있는 시스템을 구축하였다. 이를 통해 국내 5개 지역에서 채취한 암석 시료 및 시멘트 모르타르와 알루미늄 합금에 대해 시험을 수행하여 동적 물성치를 측정하고, 1회의 충격시험으로 종파 및 횡파의 공진주파수와 감쇠비를 결정하였다. 그 결과, 동탄성계수와 정탄성계수는 10%내외의 차이를 가진 결과치가 도출되었고, 동포아송비는 정포아송비에 비해 0.07 이상 높은 값이 측정되었다. 또한 풍화도가 높거나 절리가 발달한 암석일수록 감쇠비가 증가하는 현상을 관찰하였다. Impact-echo test is a non-destructive testing method to determine dynamic properties of a material. This presentation introduces the experimental set-up and procedure of the test for rock specimens. In addition, the test results of domestic rocks collected in 5 different areas, a cement mortar and aluminium alloy are presented. The test results include resonance frequencies of P- and S-wave as well as damping ratios of the described 7 different materials. The differences between dynamic and static values of elastic moduli are about 10%, while the dynamic Poisson's ratios are greater than the static Poisson's ratios by at least 0.07. The damping ratio is dependent on the joint density and degree of weathering of a rock specimen.

광통신용 1.3 ㎛ Ridge Waveguide Distributed Feedback Laser Diode의 제작과 특성 평가

박경현(K. H. Park),이중기(J. K. Lee),장동훈(D. H. Jang),유지범(J. B. Yoo),강승구(S. K. Kang),김홍만(H. M. Kim),이용탁(Y. T. Lee),박형무(H. M. Park),조호성(H. S. Cho),홍창희(T. Hong) 한국광학회 1994 한국광학회지 Vol.5 No.1

발진파장이 1.3 ㎛인 Ridge Waveguide Distributed Feedback Laser Diode(RWG-DFB-LD)를 제작하고 특성을 평가하였다. 회절격자 형성은 광간섭무늬 노광법을 이용하였고 결정성장은 LPE로 수행하였다. 제작된 RWG-DFB-LD의 발진 임계전류는 67 ㎃이었고, 1296.5 ㎚ 파장에서 측모우드 억제율 30 dB 이상으로 단일 종모우드로 발진하였다. 금지대역폭 측정에 의한 회절격자 결합계수(k)는 40 ㎝-¹로 평가되었다. 소신호 변조특성평가 결과 제작한 RWG-DFB-LD는 1.2 Ith에서 1.99 ㎓의 변조대역폭(f_(-3dB)) 특성을 보였다. We fabricated and characterized RWG-DFB-LDs emitting at 1.3 ㎛ wavelength. For fabrication of the laser diode, inteference fringe of optical beams was used for grating formation and epi layers were grown by LPE. The fablicated RWG-DFB-LD operated in a single longitudinal mode with more than 30 dB SMSR at 1296.5 ㎚ emitting wavelength and its threshold current was 67 ㎃. Coupling coefficient (k) was estimated as 40 ㎝-¹ by means of stop-band measurement. Finally, we show that the RWG-DFB-LD fabricated in this experiment can be applicable as light source of 2.5 Gbps optical communication system from the fact that the small signal response of the RWG-DFB-LD rated up to 1.99 ㎓ at pre-bias level of 1.2Ith.

Effects of 10-min of pre-warming on inadvertent perioperative hypothermia in intraoperative warming patients: a randomized controlled trial

유재화,Ok Si Young,김상호,정지원,박선영,김문규,조호범,You Gyu Wan 대한마취통증의학회 2020 Anesthesia and pain medicine Vol.15 No.3

Background: This study aimed to evaluate the efficacy of 10-min pre-warming in preventing inadvertent perioperative hypothermia, which is defined as a reduction in body temperature to less than 36.0℃ during the perioperative period in intraoperative warming patients. Methods: In this prospective randomized study, 60 patients scheduled for elective surgery under general anesthesia lasting less than 120 min were divided into two groups: the 10-min pre-warming group (n = 30) and the control group (n = 30). Patients in the 10-min pre-warming group were pre-warmed for 10 min in the pre-anesthetic area using a forced-air warmer set at 47ºC. Intraoperatively, we warmed all patients with a forced-air warmer. Body temperature was measured using a tympanic membrane thermometer pre- or postoperatively and a nasopharyngeal temperature probe intraoperatively. Patients were evaluated on the shivering and thermal comfort scale in the pre-anesthetic area and post-anesthesia care unit. Results: The incidences of intraoperative hypothermia and postoperative hypothermia were similar in both groups (10.7% vs. 28.6%, P = 0.177; 10.7% vs. 10.7%, P = 1.000 respectively). Body temperature was higher in the 10-min pre-warming group (P = 0.003). Thermal comfort during the pre-warming period was higher in the 10-min pre-warming group (P < 0.001). However, postoperative thermal comfort and shivering grades of both groups were similar.Conclusions: Ten minutes of pre-warming has no additional effect on the prevention of inadvertent perioperative hypothermia in intraoperative warming patients.

X-ray를 이용한 경부 피부에서 경막외강까지의 깊이 예측

김문규,최동혁,최동혁,김호준,박선영,김상호,정지원,유재화,조호범,옥시영 대한마취통증의학회 2017 Anesthesia and pain medicine Vol.12 No.1

Background: Previous studies have shown that measuring the distance from the skin to the ligamentum flavum by ultrasound preceding cervical epidural block can be beneficial in excluding false loss of resistance. However, the measurement value using ultrasound may vary depending on the degree of operator experience. Therefore, we aimed to determine the depth from skin to cervical epidural space by using lateral cervical spine X-ray, which is a more intuitive method. Methods: We enrolled 102 adult patients who were scheduled to undergo cervical epidural anesthesia for vascular bypass surgery of upper arm. After attaching a steel rod on the needle insertion site, lateral cervical spine X-ray was taken before the epidural procedure. We measured the distance from the steel rod to the midpoint of interlaminar space on the spinolaminar line. The X-ray depth was compared with needle depth. Results: Of the 102 enrolled patients, 18 patients including 13 in whom we were unable to measure X-ray depth were excluded from the analysis. In total, 84 patients were included in the analysis. Concordance correlation coefficient between the X-ray-measured depth and needle depth was 0.925. Bland-Altman analysis indicated a mean difference of ± 1.96 SD with 0.06 ± 0.56 cm. Conclusions: Lateral cervical spine X-ray can be useful for prediction of the midline depth from skin to epidural space, particularly for operators who are not skilled at spine ultrasound or the use the C-arm fluoroscopy.