• Radiation Oncology Journal
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• v.16 no.2
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• pp.167-175
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• 1998

Purpose : It is not a simple task to achieve the ideal isodose curve with a standard vaginal applicator or sing1e plane needle impant in the paravaginal tissue when primary or recurrent gynecological neoplasms(cervical cancers, vaginal cancers and vulvar cancers) are treated as a boost following external beam radiotherapy. The authors introduce the development and construction of a simple, inexpensive, customized applicator for volume implant to maximize the radiation dose to the tumor while minimizing the dose to the rectum and the bladder. Materials and Methods : Nine patients underwent Ir-192 transperineal interstitial implantation for either recurrent(5 cases) or primary(3 cases) cervical cancers or primary vaginal cancer(1 case) between August 1994 and February 1998 at Ajou university hospital. First 3 cases were performed with a sing1e plane implant guided by digital palpation. Because of inadequate isodose coverage in the tumor volume in first 3 cases, we designed and constructed interstitial vaginal applicator for volume implant to improve tumor dose distribution and homogeneity while sparing the surrounding normal tissue. Our applicators consist of vaginal obturator and perineal template that made of the clear acrylamide and dental mold material$(Provil^{(R)})$. The applicators were customized individually according to the tumor size and its location Both HDR and LDR irradiation were given with these applicators accomodating 6 Fr needles(Microselectron Nucletron). The pretreatment planning prior to actual implant was performed whenever possible. Results : Needles can be inserted easily and evenly into the tumor volume through the holes of templates, requiring less efforts and time for the implant procedure. Our applicators made of materials available from commercial vendors. These have an advantage that require easy procedure, and spend relatively short time to construct. Also it was possible to fabricate applicators to individualize according to the tumor size and its location and to achieve the ideal isodose coverage. We found an accurate needle arrangement and ideal dose distribution through the CT scan that was obtained in 3 cases after needle implant. Three patients with primary cervical and vaginal cancers were controlled locally at final follow up. But all recurrent cases failed to do so. Conclusion : The authors introduce inexpensive, simple interstitial vaginal templates which were self-designed and constructed using materials available from commercial vendors such as acrylanide and dental mold material $(Provil^{(R)})$.

• Journal of Energy Engineering
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• v.14 no.3 s.43
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• pp.194-202
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• 2005

The present study was analytically and experimentally carried out to predict the absorption characteristics on combined heat and mass transfer process in a vertical falling film of variable absorbers. Heat and mass transfer enhancements were analytically investigated. Effects of geometric parameters by insert device (spring) and corrugate, flow pattern on absorption performances has been also investigated. Especially, the optimal values of absorber geometry (ID=22.8mm, L=1150m) and kinetic variables (solution flow rate, flow pattern) for maximum absorption performance has been predicted by the numerical analysis. The maximum absorption performance in a numerical analysis and experiment was shown at the wavy-flow by insert device (spring).

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.4
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• pp.466-474
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• 1998

In the present study, the improvement of absorption characteristics by installing insert devices, such as spring and wire screen, inside the vertical tube absorber were studied experimentally. Momentum, heat and mass transfer rate in the absolution process of smooth bare tube, smooth tube with spring-insert, and with wire screen-insert were compared and analysed in range of film Reynolds number of 40∼200. The improvement of heat transfer rate by spring-insert and screen-insert were remarkable especially in the low Reynolds number region. As the mesh number increased in screen-insert and as the pitch decreased in spring-insert, Nusselt and Sherwood number increased. Degradation of mass transfer by non-absorbable gas showed similar qualitative trends regardless of the insert type.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1995-1996
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• 2006

검출기 안내관은 노내 핵계측 계통의 중성자 분포 측정을 위한 이동형 검출기의 이동경로를 제공할 뿐만 아니라 원자로 냉각수 계통의 압력경계를 유지하는 안전성 등급의 중요한 설비이다. 그러나, 인출과 삽입을 위한 검출기 안내관 취급은 의외로 낙후되어 작업자의 인력에만 의존하고 있는 실정이며, 원자로 격납용기 내부에 위치한 고방사선 지역에서 작업이 수행되고 있는 실정이다. 따라서 노내 핵계측 계통의 검출기 안내관의 안정적인 관리를 위해 검출기 안내판을 일정한 힘으로 인출하고 삽입할 수 있는 자동화시스템의 개발이 이루어지고 있다. 전력연구원에서 개발한 안내관 취급기구는 롤러에 의해 안내관을 파지하고, DC 모터 구동에 의해 안내관을 인출하고 삽입하는데, 본 논문에서는 안내관 취급 기구의 제어 시스템 구성과, 롤러와 안내관 사이에 발생하는 슬립을 고려한 제어기 구조를 제안하고, 실험을 통해 구현한 제어 시스템의 효용성을 보인다.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05a
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• pp.269-274
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• 1996

월성원자력발전소 2호기와 같은 CANDU 6형 원자로의 반응도제어기구 설치대에는 여러 반응도제어기구가 삽입되기때문에 원자로심으로부터의 방사선흐름현상으로 인한 방사선피폭이 예상될 수 있는 위치이다. 좁고 긴 반응도제어기구 도관에서의 방사선 흐름으로 인한 반응도제어기구 설치대에서의 방사선량을 예측하기 위해 몬테 칼로 MCNP 코드를 1차원 각분할법 코드인 ANISN과 연계하여 사용하였다. 월성원자력2호기의 상단차폐해석을 위한 ANISN 계산, 도관의 방사선흐름을 평가하기 위한 MCNP 계산, 그리고 반응도제어기구 설치대에서의 방사선량율 평가를 위한 MCNP 계산등 3단계 계산 기법의 적응이 시도되었다.

• Journal of the Korean Society of Radiology
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• v.8 no.6
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• pp.317-323
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• 2014

This study aims to suggest and test methods using an orally inserted guiding device in order to improve a motion artifact by involuntary oral motor such as removing one's dentures and swallowing saliva clinically structured cervical spine scan and to make the optimal image by minimizing motion artifact. A cervical spine test was conducted with 30 patients who wore dentures among those who had a cervical spinal disease from January 1, 2014 through June 30, 2014. As for testing methods, after removing denture, T1-TSE-Sagittal, T2-TSE-Sagittal, T1-TSE-Axial and T2-TSE-Axial were obtained in a normal position and a supine position; the orally inserted guiding device was inserted in patients' mouth; and then T1-TSE-Axial and T2-TSE-Axial were retested. As a result, in SNR, T1-TSE-Axial before inserting an orally inserted guiding device was $22.33{\pm}8.59$; T1-TSE-Axial after inserting the orally inserted guiding device was $25.21{\pm}7.93$; T2-TSE-Axial before inserting the orally inserted guiding device was $14.49{\pm}5.74$; and T2-TSE-Axial after inserting the orally inserted guiding device was $16.61{\pm}6.72$. In CNR, T1-TSE-Axial was measured at $0.23{\pm}0.01$ while T2-TSE-Axial at $0.21{\pm}0.01$. As a result of the qualitative analysis, T1-TSE-Axial before inserting the orally inserted guiding device was $3.49{\pm}0.11$; T1-TSE-Axial after inserting the orally inserted guiding device was $3.95{\pm}0.14$; T2-TSE-Axial before inserting the orally inserted guiding device was $3.25{\pm}0.18$; and T2-TSE-Axial after inserting the orally inserted guiding device was $3.68{\pm}0.09$. As a result of using an orally inserted guiding device, the resolution and contrast of the images improved as the patients' involuntary artifact decreased because of removing dentures and swallowing saliva, and it was found that the interpretation of the images and identification of the diseases improved.

• Journal of the Korean Arthroscopy Society
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• v.16 no.1
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• pp.87-91
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• 2012

A making appropriate portals is most important start in the arthroscopic surgery, and a step which determines the easiness of the operation procedures. It affects the precision of the examination of the target joints, making the next portals, and handling the instrument in the joint space. The knowledge about the normal and pathologic structures and understanding the portals should be needed to make an arthroscopic surgery ease.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.701-707
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• 2023

In PET/CT, the injection volume of ¹⁸F-FDG directly affects the SUV(standard uptake value), which can affect the reading results. Therefore, it is important to inject the correct dose value of ¹⁸F-FDG. In this study, we performed the correlation between the residual radioactivity remaining in the syringe and catheter insertion device according to the number of flushing during ¹⁸F-FDG injection. CRC-25R dose calibrator, catheter insertion devices, 3 cc syringes and 50 cc physiological saline were used in this study, and the results were statistically analyzed. As a result, the total residual radioactivity of the syringe and catheter insertion device remained the highest at 5.84% after two flushing, and the least remained at 1.49% after five flushing. The correlation analysis results showed that the number of flushing had a negative correlation with the residual radioactivity of the syringe at -0.436 and the catheter insertion device at -0.300. As a result of one-way distributed analysis of the average according to the number of flushing, the syringe showed a significant decrease at 4 times, and the catheter insertion device showed a significant decrease at 5 times. However, considering that an average of 0.8% remains in the case of catheter insertion devices, four time flushing seems to be the most appropriate.

• Progress in Medical Physics
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• v.20 no.3
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• pp.119-124
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• 2009

Stents are frequently used throughout the human body. They keep pathways open in vascular or nonvascular duct for a long time. Therefore its stability is very important factor. In recent years, aconsiderable amount of research has been carried out in order to estimate mechanical properties of the stent such as expansion pressure behavior, radial recoil and longitudinal recoil using FEM (Finite element analyses). However, published works on simulation of stent fatigue behavior using FEM are relatively rare. In this paper, a nonlinear finite-element methodwas employed to analyses the compression of a stent using external pressure and fatigue behavior. Finite element analyses for the stent system were performed using NASTRAN FX. In conclusion this paper shows how the stent is behaved in the body, and its fatigue behavior.

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.11a
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• pp.155-155
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• 1999