• Journal of Chest Surgery
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• v.37 no.4
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• pp.322-327
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• 2004

Coronary artery bypass grafting on the beating heart is no longer a new methods for any cardiac surgeon. We evaluated the application of the off-pump coronary artery bypass procedure relative to safety and efficiency as measured by postoperative complication and operative mortality. Material and Method: We used our retrospective database to compare the patients having off-pump coronary surgery (n=100) with those having on-pump coronary surgery (n=100) between June, 1999 and August, 2002. Patients whom underwent associated valvular or aortic aneurysmal operation were excluded. Result: Neither groups showed any differences in the patient's risk factors and extent of coronary disease. Off-pump CABG group did not have significantly less mean operation time (295$\pm$73 min vs 323$\pm$83 min, p=ns) and mean hospital day (15.34$\pm$6.02 day vs 13.80$\pm$4.95 day, p=ns). However, off-pump CABG group had significantly shorter mean ventilation time (17.3$\pm$11.27 hour vs 24.98$\pm$16.1 hour, p＜0.05). No patients were converted to on-pump CABG in off-pump CABG. Intraoperative hemodynamic instability in off-pump CABG were 6 cases, of whom 2 cases were in lateral wall approach and 4 cases in right coronary anastomosis. Postoperative mortality was 1 case in off-pump CABG and 2 cases in on-pump CABG. Intra-aortic ballon pump (IABP) was applied in 1 case with off-pump CABG and in 2 cases with on-pump CABG. No patients presented postoperative cerebral infarction ＆ stroke in off-pump CABG but 2 patients in on-pump CABG. Postoperative arrhythmia presented in 4 cases with off-pump CABG and in 6 cases with on-pump CABG. Acute renal failure (ARF) was complicated in 3 cases with off-pump CABG and in 2 cases with on-pump CABG. Conclusion: This study documented the immediate safety and efficiency of the off-pump CABG procedure.

• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.537-543
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• 2020

The elderly population in the modern society is growing rapidly due to advance medical technology and minimally invasive surgery. Therefore, as the tendency to use medical device is increasing, pathogenic infection is a concern. Therefore, the first aim of modern medicine is infection prevention in medical place. Recently, patient implants are increasing using 3D printing. Hydroxyapatite is used as a representative material. And, there haven't had currently absorbed dose standard for sterilization of hydroxyapatite discs. Escherichia coli and Streptococcus mutans contaminated on the surface of hydroxyapatite discs were irradiated at each absorbed dose of 0, 0.5, 1.0, 3.0, 5.0 kGy using Gamma-ray of cobalt and Electron-beam of linear accelerator. Then, the number of bacteria was measured in the sample by the decimal dilution method. After sterilization, a non-parametric testing method was performed to compare the survival of Escherichia coli and Streptococcus mutans. As a result, Escherichia coli was sterilized at 1 kGy or more and Streptococcus mutans at 3 kGy or more on absorbed dose. It is considered possible to perform sterilization at a lower value than the recommended absorbed dose of radiation sterilization.

• Journal of Biomedical Engineering Research
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• v.23 no.6
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• pp.451-458
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• 2002

Osteoporosis is a systemic skeletal disease caused by low bone mass and the decrease of bone density in the microstructure of trabecular bone. Drug therapy(PTH Parathyroid hormone) may increase the trabecular thickness and thus bone strength. Vertebroplasty is a minimally invasive surgery foy the treatment of osteoporotic vertebral compression fracture. This Procedure includes Puncturing vertebrae and filling with Polymethylmethacrylate(PMMA). Although altering recommended monomer-to-Powder ratio affects material properties of bone cement, clinicians commonly alter the mixture ratio to decrease viscosity and increase the working time. The Purposes of this study were to analyze the effect of 4he monomer-to-powder ratio on the mechanical characteristics of trabecular. In this paper, the finite element model of human vertebral trabecualr bone was developed by modified Voronoi diagram, to analyze the relative effect of hormone therapy and vertebroplasty at the treatment of osteoporotic vertebrae. Trabeuclar bone models for vertebroplasty with varied monomer-to-Powder ratio(0.40∼1.07 ㎖/g) were analyzed. Effective modulus and strength of bone cement-treated models were approximately 60% of those of intact models and these are almost twice the values of hormone-treated models. The bone cement models with the ratio of 0.53㎖/g have the maximum modulus and strength. For the ratio of 1.07㎖/g, the modulus and strength were minimum(42% and 49% respectively) but these were greater than those for drug therapy. This study shows that bone cement treatment is more effective than drug therapy. It is found that in vertebroplasty, using a monomer-to-powder ratio different from that recommended by manufacturer nay significantly not only reduce the cement's material Properties but also deteriorate the mechanical characteristics of osteoporotic vertebrae.

• Journal of Chest Surgery
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• v.35 no.12
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• pp.882-889
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• 2002

Acute Complications of Remodelling Plasty of Costochondral Rib Cage For Pectus excavatum Recently, Remodelling Plasty of Costochondral Rib Cage has been introduced as an minimally invasive procedure and expanded its application for pectus excavatum. Outcomes and acute complications were reviewed Material and Method: A retrospective survey of 55 patients who underwent Remodelling Plasty of Costochondral Rib Cage from September, 1999 to February, 2002 was conducted to review complications, postoperative treatments, and outcomes. Result: Age ranged from 1 to 27 years(mean 11.4 $\pm$ 7.1). 35(64%) were less than 15-year old and 20(36%) were more than 15-year old. There were 44(80%) Male patients and 11(20%) female patients. Length of hospital stay was 7.8 $\pm$ 2.1 days for less than 15-Y-old group, 10.6 $\pm$ 6.2 days for more than 15-Y-old group(p ＝ 0.042) One substernal bar was inserted in 52 patients and two substernal bars were inserted in 3 patients. As for stabilizer, one lateral side was fastened in 15 patients and both lateral sides were fastened in 6 patients. In the less than 15-Y-old group, 4 patients needed stabilizer, whereas in the more than 15-Y-old group, 18 patients needed stebilizer(s)(p ＝ 0.000). Including all kinds of complications, 28(51 %)patients had postoperative complications. Of them, only 7 patients were treated for complications(C-tube insertion was done in 7 patients and reoperation for bar refixation or removal was done in 3 patients of them). Conclusion: Most complications after Remodelling Plasty of Costochondral Rib Cage For Pectus Excavatum were trivial without treatment although C-tube drainage was needed in some patients. However bar displacement such as rotation and lateral sliding should be corrected as soon as detected in order not to remove the bar(the worst situation).

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.1
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• pp.47-54
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• 2017

The atrophy of edentulous ridge and pneumatization of the maxillary sinus often limit the volume of bone available for implant placement on maxillary posterior teeth. Most clinicians suffer difficulties from poor bone quality and quantity on maxillary posterior site. Thus, the success of maxillary posterior implant surgery depends on the increase of the available bone and obtaining a good initial stability of the implant after maxillary sinus reconstruction. The maxillary sinus augmentation methods include a crestal approach and a lateral approach. Less morbidity and complications after operation is major advantage to sinus augmentation using crestal approach than lateral approach. However, when the residual ridge height is ${\geq}6mm$, it is known that crestal approach is appropriate. Also delayed implantation after sinus augmentation is recommended in severely atrophic ridge. We present the three cases of implant placement simultaneously sinus augmentation using crestal approach in posterior maxilla site with ${\leq}3mm$ of residual alveolar bone.

• Journal of Chest Surgery
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• v.41 no.4
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• pp.469-475
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• 2008

Background: Video-assisted thoracic sympathicotomy is a definitive minimally invasive treatment for axillary hyperhidrosis. Different techniques exist for controlling axillary hyperhidrosis, but they are temporary and expensive. We compared the results after using two different levels of sympathicotomy for treating axillary hyperhidrosis: T3-T4 and T4. Material and Method: Between June 2002 and May 2007, 30 patients with isolated axillary hyperhidrosis underwent either T3-T4 or T4 thoracoscopic sympathicotomy in the Department of Thoracic & Cardiovascular Surgery at Wonkwang University Hospital. The patients were divided into two groups. Group I (n=15) was composed of patients who underwent T3-T4 sympathicotomy (thermal ablation), and Group II (n=15) was composed of patients who underwent T4 sympathicotomy (thermal ablation). The procedures were bilateral and simultaneous, involving the use of two 2-mm trocars and a 0-degree 2-mm thoracoscope under general anesthesia with single endotracheal intubation. Outcome parameters included satisfaction rate of treatment, degree of compensatory sweating, and postoperative complications. Patients were interviewed by telephone regarding satisfaction and compensatory hyperhidrosis. Result: There were no differences in age between group I and group II. The mean follow-up for the T3-T4 group was $38.7{\pm}2.3$ months, and the mean follow-up for the T4 group was $18.7{\pm}3.6$ months. The immediate therapeutic success rate (within 2 weeks postoperative) was 100% in both groups, and there were no recurrences in either group during the long-term follow-up period. The satisfaction rate was higher (93.3%) in the T4 group than in the T3-T4 group (53.3%), and the incidence of compensatory hyperhidrosis was lower in the T4 group (6.7%) than in the T3-T4 group (46.7%). Postoperative complications included one mild pneumothorax and two instances of intercostal neuralgia. Digital infrared thermographic imaging (DITI) correlated well with postoperative satisfaction. Conclusion: Both techniques proved effective for controlling isolated axillary hyperhidrosis. The T4 group had a higher satisfaction rate and lower severity of compensatory hyperhidrosis. Hence, thermal ablation of the lower interganglionic fibers of the third thoracic sympathetic ganglion on the fourth rib is a more practical and minimally invasive treatment than is the T3-T4 surgical method, according to the degree of compensatory sweating in isolated axillary hyperhidrosis.

• Journal of the Korean Arthroscopy Society
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• v.10 no.1
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• pp.118-122
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• 2006

Purpose: We introduce a technique of all inside arthroscopic capsular imbrication and lateral release used to treat patellofemoral instability. Methods: With the arthroscope in the anteromedial portal for best viewing, the arthroscopic scissor is placed through superolateral portal for proximal to distal release. The release performed 5mm to 1cm from the edge of the patella. After completion of the procedure, with the arthroscope in anterolateral portal, we inserted 5mm cannula in superolateral portal and made working portal from superomedial portal. Medial reefing was performed with all inside technique by using curved needle of the spectrum suturing system and No. 1 monofilament PDS suture is passed through the superomedial portal percutaneously and retrieved through a superolateral portal. Conclusion: Several methods for arthroscopic patella realignment have been proposed, but they have consisted primarily of arthroscopically assisted techniques using a medial incision. We believe that our procedure is preferable to arthroscopically assisted methods commonly used, in that an incision is avoided and the vastus medialis obliqqus is not violated. Our technique is minimally invasive and is easy to control the tightness of the medial patellofemoral ligament (MPFL) under direct vision.

• Journal of the Korean Arthroscopy Society
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• v.10 no.2
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• pp.214-218
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• 2006

Purpose: We describe a new technique of arthroscopic medial plication using pull-out suture with consideration of anatomical location of medial patellofemoral ligament for the treatment of acute or recurrent patellar dislocation. Operative technique: Under arthroscopic examination, sutures are passed through the medial capsule, at which medial patellofemoral ligament is located, from outside to inside of knee joint. Three guide wires are inserted from anterior surface of the patella to upper half of its medial border. Intraarticular portions of sutures are pulled out toward anterior surface of the patella through bony tunnels. Under appropriate tension, the sutures are tied after performing lateral retinacular release. Conclusion: As suturing medial patellofemoral ligament, this technique can maximize the effect of medial plication and can correct subluxation and tilt of the patella. It seems to be a minimally invasive, easy and effective method for the treatment of acute or recurrent patellar dislocation.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.681-686
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• 2010

Background: A chest computed-tomography has become more prevalent so that it is more common to detect small sized pulmonary nodules that have not been found in previous simple chest x-ray. If those detected nodules are undersized or located in pulmonary parenchyma, it is difficult to accomplish a biopsy since it is vulnerable to explore them either grossly or digitally. Thus, in our hospital, a thoracoscopic pulmonary wedge resection was performed after locating a lesion by means of hook wire with CT-guided. Material and Method: 31 patients (17 males and 14 female patients) from December in 2006 to June in 2010 became our subjects; their 34 pulmonary nodules were subjected to the thoracoscopic pulmonary wedge resection after locating a lesion by means of hook wire with CT-guided. Also we analyzed a possibility of hook wire dislocation, a frequency of conversion to open thoracotomy, time consumed to operation after location of a lesion, operation time, post operation complication, and histological diagnosis of the lesion. Result: 12 of 34 cases were ground glass lesion, whereas 22 cases of them were solitary pulmonary lesion. The median value of the lesion was 8mm in size (range: 3 to 23 mm), while the median value was 12.5 mm in depth (range: 1 to 34 mm). The median value of time consumed from location of the lesion to anesthetic induction was 86.5 minutes (41~473 minutes); furthermore the mean value of operation time was 103 minutes (25~345 minutes). Intrathoracic wire dislocation was found in one case, but a target lesion was successfully excised. Open thoracotomy was performed in four cases due to pleural adhesion. However, there was no case of conversion to open thoracotomy due to failure to detect a target lesion. In histological diagnosis, metastatic cancer were found in 15 cases, which were the most common, primary lung cancer were in 9 cases, non-specific inflammation were in 3 cases, tuberculosis inflammation were in 2 cases, lymph nodes were in 2 cases, active tuberculosis were in 1 case, atypical adenomatous hyperplasia was in 1 case and normal lung parenchymal finding was in 1 case, respectively. Conclusion: In our hospital, in order to accomplish a precise histological diagnosis of ground-glass lesion and pulmonary nodules in lung parenchyma, location of pulmonary nodules were exactly located with hook wire under chest computed-tomography, which was followed by lung biopsy. We concluded that this was an accurate, minimally invasive and valuable method to minimize the complications and increase of cost of medical service provided.

• Science of Emotion and Sensibility
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• v.8 no.1
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• pp.17-28
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• 2005

With the advent of computer technology, the fundamental nature of products has shaped from physical forms towards product interactivity, The focus is now on usability of the product with ease and efficiency rather than conversing with just the looks of the product. However, most definitions of usability and contemporary usability-related researches, have focused on the performance-oriented functional aspects of usability (i.e., how well users perform tasks using a product). Today, user expectations are higher; products that bring not only functional benefits but also emotional satisfaction. So far, there have been many studies on human emotions and the emotional side of products in the field of emotional engineering. Contemporary emotion-related researches have focused mainly on the relationship between product aesthetics and the emotional responses elicited by the products, but little is known about emotions elicited from using the products. The main objective of our research is analyzing user's emotional changes while using a product, to reveal the influence of usability on human emotions. In this research, we suggested conceptual framework for the study on the relationship between usability of products, and human emotions with emphasis on mobile phones. We also extracted emotional words for measuring user's emotions expressed not from looking at the product's appearance, but from using the product. First, we assembled a set of emotions that is sufficiently extensive to represent a general overview of the full repertoire of Korean emotions from the literature study. Secondly, we found emotional words in the after note by the users on the websites. Finally, verbal protocols in which the user says out loud what he/she ks feeling while he/she ks carrying out a task were collected. And then, the appropriateness of extracted emotional words was verified by the members of the consumer panel of a company through web survey. It is expected that emotional words extracted in this research will be used to measure user's emotional changes while using a product. Based on the conceptual framework suggested in this research, basic guidelines on interface design methods that reflect user's emotions will be illustrated.