Large vibration-desensitized fiber-optic point-diffraction interferometer for on-machine measurement

학위논문(박사) - 한국과학기술원 : 기계공학전공, 2011.2, [ v, 102 p. ]오늘날 대형 광학계에 대한 수요는 갈수록 증가하고 있는 상황이다. 이러한 대형 타깃을 제작하는 경우 가공과 측정의 과정을 반복적으로 수행해야 한다. 따라서 필연적으로 가공기 위에서 측정을 직접 수행하는 기상측정(機上測定)이 필요해진다. 한편 이러한 대형 타깃을 측정하는 경우, 광간섭계 방법이 그것의 성능과 측정 용이성 때문에 가장 좋은 측정 방법으로 주목 받고 있다. 그러나 이러한 광간섭계를 이용하여 가공기 위에서 측정을 진행하는 경우, 주변 환경에 많이 영향을 받는다는 단점을 동시에 가지고 있다. 따라서 이러한 문제를 해결하기 위해 많은 연구들이 진행되어 왔다. 이러한 연구들 중에 가장 훌륭한 성능을 보이는 간섭계 중의 하나로 공통 경로를 이용한 광섬유 점회절 간섭계가 있다. 그러나 이러한 점회절 간섭계는 기준 파면의 광량이 타깃 진동에 의해 변화하며 큰 진폭의 진동에는 대응이 안 되는 단점을 가지고 있다. 따라서 본 연구는 두 가지 핵심 기능으로부터 광섬유 점회절 간섭계를 개선하고자 한다. 먼저 첫 번째 기능으로 진동에 대한 허용량을 높이기 위해 벤드 로스 기술을 적용한 다중 모드 광섬유를 점회절 장치로서 사용한다. 두 번째 기능으로 광섬유 출력단에 광량 증폭 및 안정화를 위해 다이오드 레이저를 이용한 주입 잠금 장치를 사용한다. 언급한 두 개의 시스템을 이용하여 고진동 둔감 특성의 광섬유 점회절 간섭계를 얻을 수 있었고 실험을 통해 이것의 성능을 검증하였다.한국과학기술원 : 기계공학전공

Profile measurements of silicon wafers using a vibration-desensitized optical interferometer

We devised a vibration-insensitive interferometer with a common-path scheme of generating the reference wave directly by transmitting the measurement wave through a single-mode fiber. This fiber-diffraction interferometer enables to cancel out the dominating vibration effect encountered commonly in both the reference and measurement waves in the due course of the two waves’ interference. Besides, to suppresss parasite vibration disturbances caused to interferometer hardware components, a special type of spatial phase-shifter is added to capture four phase-shifted interferograms simultaneously without time delay using a single camera shot. The proposed interferometer system is capable of providing a high level of vibration immunity that is found useful for testing large scaledsilicon wafer's surface profile when sufficient ground isolation for anti-vibration is not feasible

Reduced bladder capacity without daytime voiding symptoms with nocturnal enuresis

Background: This study aimed to evaluate the prevalence of monosymotomatic nocturnal enuresis (MSNE) with reduced bladder capacity in children with primary nocturnal enuresis (NE) and to suggest treatment outcomes. Methods: This study retrospectively evaluated 54 children (30 males, 24 females; median age: 8; range: 5?14) who were newly diagnosed with primary NE from November 2017 to October 2019. Reduced bladder capacity in MSNE was defined when a patient’s maximal voided volume (MVV) from his or her voiding diary was 75% or less than estimated functional bladder capacity ([age + 1] x 30 mL) for his or her age and there were no daytime lower urinary tract symptoms (LUTS) as assessed using history taking and questionnaires. Results: Nineteen (35.2%) of 54 children with newly diagnosed primary NE did not report daytime LUTS. Fifteen children (27.8%) had a reduced bladder capacity and were prescribed anticholinergic or beta-3 agonist. After three months of medication, MVV significantly increased from 117.5 mL to 183.3 mL (P = 0.010), but frequency showed no significant change from 5.7 to 4.9 times a day. Improvement in enuresis occurred completely and partially in 41.7% and 25% of participants, respectively. Conclusions: The prevalence of reduced bladder capacity without daytime voiding symptoms was relatively high as 27.8% in children newly diagnosed with primary NE. In primary MSNE, reduced bladder capacity should be investigated using a frequency-volume chart in addition to thorough history taking or questionnaires. Anticholinergics or beta-3 agonists for MSNE with reduced bladder capacity are effective at increasing the bladder capacity of these patients

Outcomes of extracoporeal shock wave lithotripsy for ureteral stones according to ESWL intensity

Baekground: We evaluated the treatment outcomes of ureteral stones according to energy intensity generated by ESWL. Conclusions: Stone size and HU affected the ESWL success rate. ESWL intensity was not significantly relate to the success rate, so it should be adjusted accordig ton patient pain and the degree of stone fragmentation

Varying Outcomes among Patients with Large Angiomyolipomas according to the Treatment Method

Purpose: This study aimed to evaluate the outcomes of large angiomyolipoma (AML) treatment by selective arterial embolization (SAE) versus nephron-sparing surgery (NSS) using a robotic surgical system. Materials and Methods: Between January 2011 and June 2018, we retrospectively reviewed 25 patients who underwent robot-assisted partial nephrectomy (RAPN) or SAE for large AMLs. Ten patients underwent RAPN, and 15 underwent SAE. Patient demographics, AML characteristics, and operative and postoperative clinical outcomes were recorded and analyzed. Outcomes were compared between patients who underwent RAPN and patients who underwent SAE. Specifically, changes in renal function and size were evaluated after the treatment. Results: The mean age of the patients was 52.9 years, and 22 of 25 patients were female. The mean maximum AML diameter on computed tomography was 8.9 cm, and 8 patients had multiple masses. Twenty-two of 25 patients had moderate to high RENAL complexity. Patients who underwent SAE had more symptoms (p = 0.018) and higher RENAL complexity scores (p = 0.013) on average. On average, tumor size decreased by 99% among RAPN patients and by 58% among SAE patients (p = 0.001). Although the mean pretreatment estimated glomerular filtration rate (eGFR) was higher among RAPN patients (99.8 vs. 80.0 mL/min/1.73 m(2), p = 0.043), there were no significant changes in eGFR in either group after the treatment. One patient in the RAPN group experienced complications, but the postoperative ileus resolved without intervention. Conclusions: Both RAPN and SAE were effective and feasible treatment options for large AMLs. The AML characteristics and the condition of the patient might be important in determining the appropriate treatment method

Efficacy and tolerability of mirabegron compared with solifenacin for children with idiopathic overactive bladder: A preliminary study

Purpose: To compare the efficacy and tolerability of mirabegron and solifenacin in pediatric patients with idiopathic overactive bladder (OAB) and to identify factors affecting OAB symptom improvement after treatment. Materials and Methods: We retrospectively reviewed 103 patients (5-15 years old) who visited our hospital with OAB symptoms between July 2017 and March 2019. All participants had received solifenacin or mirabegron. Those who had secondary OAB or who did not complete the frequency-volume chart either before or after treatment were excluded. The age-adjusted bladder capacity ratio was used to evaluate bladder capacity. Efficacy was assessed on the basis of patient reports and changes in the frequency-volume chart, and >= 90% reduction was regarded as "responding to medication." Tolerability was assessed by obtaining reports from patients about the adverse effects of the drug. Results: After the exclusion of 58 patients, 45 patients (29 in solifenacin-group and 16 in mirabegron-group) were included in the primary analysis. The age-adjusted bladder capacity ratio increased from 0.71 to 0.96 (p<0.001) and from 0.57 to 0.97 (p=0.002) after solifenacin and mirabegron use, respectively. Decreased bladder capacity before medication was associated with responding to medication (odds ratio, 7.41; p=0.044). There was no significant difference in efficacy between the two drugs. Drug-induced adverse effects were reported in only 3 (10.3%) of the solifenacin-treated patients. Conclusions: Mirabegron showed comparable efficacy to solifenacin in pediatric patients with idiopathic OAB. Additionally, only few adverse effects were reported, suggesting that mirabegron can be a safe alternative for the treatment of idiopathic pediatric OAB