• Journal of Periodontal and Implant Science
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• v.34 no.3
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• pp.551-562
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• 2004

The purpose of this study was to evaluate the effects of negatively electric field on bone healing in rabbit segmental long bone defects using negatively charged PTFE membrane. Ten millimeter segmental defects in the rabbit radius were used as the experimental model. After membranes were then charge injected using a corona-charging apparatus, the left defects were covered with non charged PTFE membranes as control groups, whereas the right defect was covered with negatively charged PTFE membranes as test group. The animals were divided into 4 groups of 2 rabbits each, and sacrificed at 2, 4, 6, and 8 weeks. Histomorphometric analysis showed a more newly formed bone in negatively charged membrane at early healing period. At 2 weeks, the proportion of new bone formation to total defect area was 0.32% in control group, 1.10% in experimental group. At 4 weeks, the proportion of new bone formation to total defect area was 6.86% in control, and 13.75% in experimental. At 6 and 8 weeks, no obvious difference was found between the two groups but newly formed bone in test groups were slightly more than that in control groups. In conclusion, negatively charged membranes showed more newly bone tissue than noncharged membranes at an early healing period. Although the number of samples was small, this study showed that the combination of negatively electrical stimulation and P1FE membrane may be of value in long bone healing.

• Tuberculosis and Respiratory Diseases
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• v.67 no.1
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• pp.21-26
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• 2009

Background: Non-invasive positive pressure ventilation (NPPV) ensures adequate gas exchange during bronchoscopy in spontaneously breathing, hypoxemic patients, thus avoiding endotracheal intubation. However, in some patients, endotracheal intubation is eventually required after bronchoscopy. This study investigated the incidence of intubation and predictors of a need for emergency intubation prior to NPPV bronchoscopy initiation. Methods: On a retrospective basis, we reviewed the medical records of 36 patients (median age, 55 years; interquartile range [IQR], 43~65 years) with acute hypoxemic respiratory failure who required NPPV during bronchoscopy between January 2005 and October 2007. Results: All patients were hypoxemic (median $PaO_2/FiO_2$ ratio 155; IQR 90~190), but tolerated bronchoscopy with NPPV support. SOFA score and SAPS II score immediately before NPPV initiation were 4 (3~7) and 36 (30~42), respectively. Seventeen (47%) patients needed endotracheal intubation at a median time of 22 (2~50) hours after bronchoscopy. Patients who needed intubation after bronchoscopy had a higher in-hospital mortality (11 [65%] vs. 4 [21%], p=0.017). Upon multiple logistic regression analysis, the need for intubation after bronchoscopy was independently associated with a $P_aO_2/FiO_2$ ratio (OR, 0.961; 95% CI, 0.924~0.999; p=0.047) immediately before NPPV initiation for bronchoscopy. Conclusion: The severity of the hypoxemia immediately prior to NPPV initiation for bronchoscopy was associated with the need for intubation after bronchoscopy in patients with hypoxemic respiratory failure.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.188-192
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• 2018

Surgery to increase cerebral blood flow is one of the treatment methods of cerebral infarction. However, invasive methods, such as surgery, may result in postoperative complications or side effects. In order to supplement this invasive method, non-invasive devices have been introduced that use human blood pressure to pressurize the extremities to increase cerebral blood flow. However, the problem of poor speed and accuracy was raised. In this paper, the perfusion index of each arm was measured by applying pressure to both arms using Blood Oxygen Level Sensor to improve the accuracy of measurement and measurement time. The pressure applied to the arm by 75% of the moment when it falls to the leg and the pressure calculated by using the pressure value obtained from the arm. Like the existing blood pressure measuring cerebral blood flow increasing device, the blood flow can be increased by more than 20% and the measurement time can be shortened, so that it can be selectively used for the patient with cerebral infarction.

• Journal of the Korean Orthopaedic Association
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• v.56 no.6
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• pp.540-545
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• 2021

A transverse fracture is the most common type of displaced patella fracture requiring surgery. These fractures are commonly fixed with parallel Kirschner wires or screws that cross the fracture line, often with an additional tension band. Nevertheless, conventional fixation methods of patella fractures have prevalent complications caused by the protrusion of wires or pins. These complications necessitate additional surgery for hardware removal, increase medical cost, and can limit the function of the knee joint. This paper reports cases treated with a minimally invasive load-sharing percutaneous suture of the patella tendon. The procedure provides reliable fixation for transverse patella fractures, minimizes soft tissue injuries, preserves blood flow, and reduces postoperative pain. In addition, the procedure also reduces the irritation and pain caused by the internal fixture, thereby reducing the risk of restricted knee joint movement.

• Clinical and Experimental Pediatrics
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• v.48 no.7
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• pp.696-700
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• 2005

Propose : Body composition by bioelectrical impedance analysis(BIA) is a very useful method of analysing body composition. BIA is non-invasive, inexpensive, nonhazaedous and reproducible technique. The aim of this study was to determine the level of agreement between body composition measurement by BIA and dual-energy X-ray absorptiometry(DEXA). Methods : Data was examined in 100 children(male 58; female 42), who visited Pusan National Hospital. Weight(kg) and height(cm) were measured, and body compositions were analyzed with fat mass, lean body mass, body fat percent by BIA and DEXA methods. Results : Comparison of the DEXA and BIA methods showed highly statistically significant correlations in measurement of human body composition(fat mass, lean body mass, body fat percent). Conclusion : BIA should be considered as the method of choice in measurement of human body composition, since it's non-invasive, reliable, rapid, nonhazaedous and inexpensive, using portable equipment.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.4
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• pp.279-285
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• 2017

In this paper, the resonator with a parallel plate capacitor is newly proposed around sub-microwave frequency band and applied to earlobe for non-invasive glucose monitoring the human biological tissue. The capacitor including the earlobe as dielectric material is connected to inductive slot in the ground plane of the microstrip line. Based on the simulation, one port resonator circuit is designed and fabricated as a prototype. Three step glucose concentration levels(0, 250, 500 mg/dL) was tested, and its reflection coefficients($S_{11}$) were measured. Owing to high Q resonator more than 100, resonant frequency shift of about 9 MHz per glucose level of 250 mg/dL has been successfully measured. This proves that the proposed sensor is applicable to a blood glucose sensor.

• Journal of Chest Surgery
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• v.32 no.8
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• pp.693-701
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• 1999

Recently non-invasive diagnostic imaging replaced the invasive catheter angiography in the diagnosis of vascular disease. Catheter methods are now almost confined to the purpose of intervention. Coronary artery or coronary artery bypass graft still needs catheter technique because of small diameter and the cardiac motion. The last challenge for radiologists in this domain is to obtain a non-invasive imaging. Electron beam tomography(EBT) for high temporal resolution is able to obtain a coronary arteriogram or coronary artery bypass graft (CABG), of which CABG imaging is quite useful for the evaluation of patency. In our experience as well as others, the accuracy of EBT angiogram in evaluating CABG patency revealed that the accuracy of patency of saphenous vein grafts(SVG) is high due to relatively wide lumen, short and straight course and less influence from cardiac motion. The sensitivity and specificity of patency of SVGs were 92%, 97% respectively in the prospective evaluat on and 100% each in the retrospective evaluation. A false positive and a false negative case are rudimentary errors in the initial learing period. In contrast the analysis of left internal mammary artery(LIMA) graft was difficult due to the inherent small size and the adjacent surgical clips provoking beam-hardening artifact; therefore, the method of combining 3 dimensional reconstruction and flow mode study was important in improving the accuracy of LIMA patency. The sensitivity and specificity of LIMA patency were 100% and 80% in both prospective and retrospective evaluation. Therefore, EBT angiography is an accurate non-invasive diagnostic modality for evaluating the patency of CABG, particularly in SVGs. The accuracy can be improved with the improvement of the EBT and the development of the image reconstruction software.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.1124-1129
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• 2009

This study aims to examine the effects of non-invasive constant microcurrent stimulation on expression of Bone Morphogenetic Protein(BMP) 4 after tibia fracture in rabbits. Twenty four rabbits with tibia fracture were randomly divided into control and experimental groups. Each group was divided into four subgroups, based on the duration of the experiment (3, 7, 14, 28 days). The experimental groups received a constant microcurrent stimulation of $20{\sim}25{\mu}A$ intensity with surface Ag-AgCl electrode (diameter 1cm, Biopac, U.S.A.) for 24 hours a day. Cathode of the microcurrent stimulator located on the tibia directly, anode of it did on the gastrocnemius muscle. Rabbits were sacrificed on each of the postoperative days 3, 7, 14, 28. To investigate how non- invasive constant microcurrent stimulation affects bone healing, immunohistochemical analysis of BMP-4 was performed at each point. After evaluation, the test results are as follows: Comparisons of immunohistochemical observation of BMP-4 in 7 days after tibial fracture show that there was shown to be a moderate positive reaction (++) on concentric circles of Harversian system andt he interstitial lamella in the control group, while there was a very strong positive reaction (++++) on concentric circles of Harversian system and interstitial lamellain the experimental group. These results suggest that applying non-invasive constant microcurrent stimulation on fractured bone is helpful to bone healing.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.3
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• pp.263-270
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• 2019

Current trends in restorative dentistry focus on improving the esthetics and keeping the sound dental tissues as long as possible. The aims of this case report were to describe the successful outcome of cubic-phase zirconia laminate veneers for a patient with isolated microdontia by using a digital workflow, and to describe their clinical implications. A 15-year-old female who had isolated microdontia in combination with spacing visited Ajou University Dental Hospital for esthetic treatment. In this case, 6 maxillary anterior teeth were restored with cubic-phase zirconia laminate veneers without tooth structure removal by using a digital impression, computer-aided design (CAD) software, and computer-aided manufacturing (CAM) procedures. At 6-month follow-up, no distinct mechanical and biological complications were detected and the prostheses exhibited satisfactory esthetics and functions. Due to its favorable tissue responses and enhanced translucency, cubic-phase zirconia can be a suitable strategy for a noninvasive esthetic approach.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.05a
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• pp.179-182
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• 2001

인체 활동에 따라 우리 몸에는 다양한 전기적 생체신호가 발생하며 특히 뇌의 활동에 따라 발생되는 뇌파(EEG)는 비침습적 방법으로 측정될 수 있는 장점 때문에 뇌기능 연구 및 임상 등에서 널리 사용되어지고 있다. 또한 임상에서는 주로 뇌 신경계 질환환자의 병인 규명 및 기전 연구를 위하여 뇌파가 사용되어지고 있다. 최근에는 컴퓨터 발달에 따라 카오스, 비선형 이론 등의 다양한 방법으로 복잡한 시계열 신호인 뇌파를 분석하는 기법들이 개발되어 뇌파의 특징점을 찾아 임상에 활용하거나 뇌기능 연구에 적용하려는 연구가 진행되고 있다. 본 논문에서는 잡화(artifact)가 섞여 있는 뇌파신호 및 artifact가 제거된 다음 재구성된 뇌파신호(reconstructed EEG signal), 그리고 독립성분으로 분리된 각각의 신호에 대하여 특징점을 찾기 위하여 비선형 및 선형 분석을 실시하여 유의한 차이점을 밝혔다.