• Korean Journal of Applied Biomechanics
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• v.22 no.3
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• pp.277-284
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• 2012

The purpose of this study was to find out the changes in beginners' batting movements after taking undergraduate baseball lectures, by comparing and analyzing the speed of bat, the angle of body and its segments, the angular velocity and so on. For this purpose, the author picked up five undergraduates who had not taken baseball lectures, and conducted three-dimension computerized tomography twice on them, that is, before and after taking baseball classes, with eight infrared cameras and two force platforms. The conclusions are, first, the time required for swing was shortened after taking the classes. Second, the maximum velocity of the bat-end was increased. Third, at the time of impact, while the rotation angles of the pelvis and the tip of left foot were increased, the left elbow had more flexion after the classes. Fourth, the size of ground reaction force was increased at the point of swing where the ground reaction force of left foot became maximized. As we can infer from these conclusions, beginners' hitting movements before taking baseball classes tended to swing only with the arms, without waist rotation and weight shift of the lower body, but after the classes, their movements were proved to be corrected into the swing using the lower body. For the future studies, the author expects a research in a close to real environment by using pitching machine.

• Journal of Chest Surgery
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• v.42 no.3
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• pp.361-363
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• 2009

A 17-year-old male patient was referred with symptoms of dyspnea. Multi-detector computerized tomography (MDCT) and echocardiography evaluation revealed quadricuspid aortic and pulmonary valves, an atrial septal defect (ASD), and pulmonary stenosis. We closed the ASD using a bovine patch and performed a commissurotomy of the pulmonary valve. Quadricuspid semilunar valves are very rare congenital abnormalities that are reported to occur nine times more frequently in the pulmonic valve than in the aortic valve. According to the Hurwitz Roberts classification, the aortic valve was type A, and the pulmonic valve was type B. The aortic valve normal function, but the pulmonic valve was stenotic and had abnormal function.

• Journal of Korean Neurosurgical Society
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• v.48 no.2
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• pp.181-184
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• 2010

A case of idiopathic hypertrophic cranial pachymeningitis (IHCP) misdiagnosed as an acute subdural hematoma is reported. A 37-year-old male patient presented with headache following head trauma 2 weeks earlier. Computerized tomography showed a diffuse high-density lesion along the left tentorium and falx cerebri. Initial chest X-rays revealed a small mass in the right upper lobe with right lower pleural thickening, which suggested lung cancer, such as an adenoma or mediastinal metastasis. During conservative treatment under the diagnosis of a subdural hematoma, left cranial nerve palsies were developed (3rd and 6th), followed by scleritis and uveitis involving both eyes. Magnetic resonance imaging (MRI) revealed an unusual tentorium-falx enhancement on gadolinium-enhanced T1-weighted images. Non-specific chronic inflammation of the pachymeninges was noticed on histopathologic examination following an open biopsy. Systemic steroid treatment was initiated, resulting in dramatic improvement of symptoms. A follow-up brain MRI showed total resolution of the lesion 2 months after steroid treatment. IHCP should be included in the differential diagnosis of subtentorial-enhancing lesions.

• The Journal of the Korean bone and joint tumor society
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• v.5 no.1
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• pp.51-55
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• 1999

Aspirin has usually been taken for pain relief originating in the nidus of osteoid osteoma, however it takes too long to become effective. Because of the protracted painful course and the unpredictability of regression, osteoid osteoma is usually removed. And then, the defective host bone is internally fixed by plate and screws and augumented by autogenous bone graft. However, the common intracortical location and exuberant periosteal reaction hinders the exact intraoperative localization of the nidus. The authors managed 6 patients by computerized tomography-guided percutaneous nidus excision with a relatively small skin incision, small cortical window, short operation time and no bone graft. It may be one of the best options for removal of the nidus of osteoid osteoma with certainty.

• Journal of Korean Neurosurgical Society
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• v.46 no.5
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• pp.451-458
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• 2009

Objective : The purpose of this study was to analyze risk factors that are associated with intracranial lesion, and to propose criteria for classification of mild head injury (MHI), and appropriate treatment guidelines. Methods : The study was based on 898 patients who were admitted to our hospital with Glasgow Coma Scale (GCS) score of 13 to 15 between 2003 and 2007. The patients' initial computerized tomography (CT) findings were reviewed and clinical findings that were associated with intracranial lesions were analyzed. Results : GCS score, loss of consciousness (LOC), age and skull fracture were identified as independent risk factors for intracranial lesions. Based on the data ana lysed in this study, MHI patients were divided into four subgroups : very low risk MHI patients are those with a GCS score of 15 and without a history of LOC or headache; low risk MHI patients have a GCS score of 15 and with LOC and/or headache; medium risk MHI patients are those with a GCS score of 15 and with a skull fracture, neurological deficits or with one or more of the risk factors; high risk MHI patients are those with a GCS score of 15 with abnormal CT findings and GCS score of 14 and 13. Conclusion : A more detailed classification of MHI based on brain CT scan findings and clinical risk factors can potentially improve patient diagnosis. In light of our findings, high risk MHI patients should be admitted and treated in same manner as those with moderate head injury.

• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.6
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• pp.767-776
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• 1985

Unsteady thermally stratified flow caused by two-dimensional surface discharge of warm water into a oblong channel was investigated. Experimental study was focused on the rapidly developing thermal diffusion at small Richardson number. The basic objective were to study the interfacial mixing between a flowing layer of warm water and an underlying body of cold water and to accumulate experimental data to test computational turbulence models. Mean velocity field measurements were carried out by using NMR-CT (Nuclear Magnetic Resonance-Computerized Tomography). It detects quantitative flow image of any desired section in any direction of flow in short time. Results show that at small Richardson number warm layer rapidly penetrates into the cold layer because of strong turbulent mixing and instability between the two layers. It is found that the transfer ofheat across the interface is more vigorous than that of momentum. It is also proved that the NMR-CT technique is a very valuable tool to measure unsteady three dimensional flow field.

• Journal of Biomedical Engineering Research
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• v.28 no.3
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• pp.332-337
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• 2007

In the early twenty-first century, minimally invasive surgery is the mainstay of various kinds of surgical fields. Surgeons gave percutaneously surgical treatment of the screw directly using a fluoroscopic view in the past. The latest date, they began to operate the fractured carpal bone surgery using Computerized Tomography (CT). Carpal bones composed of wrist joint consist of eight small bones which have hexahedron and sponge shape. Because of these shape, it is difficult to grasp the shape of carpal bones using only CT image data. Although several image segmentation studies have been conducted with carpal bone CT image data, more studies about carpal bone using CT data are still required. Especially, to apply the software implemented from the studies to clinical fIeld, the outcomes should be user friendly and very accurate. To satisfy those conditions, we propose modified multi-seed region growing segmentation method which uses simple threshold and the canny edge detector for finding edge information more accurately. This method is able to use very easily and gives us high accuracy and high speed for extracting the edge information of carpal bones. Especially, using multi-seed points, multi-bone objects of the carpal bone are extracted simultaneously.

• The Journal of Korean Medicine
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• v.21 no.4
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• pp.236-241
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• 2000

Background and Purpose : Cerebrovascular accident is a serious neurologic event. It can have temporary or permanent effects on survivors, including memory, cognition and volitional control of voiding. The purpose of this study is to evaluate the clinical effect of moxibustion in patients with voiding dysfunction after a cerebrovascular accident. Methods : Twenty patients with post-stroke voiding dysfunction were studied. All patients had computerized tomography(CT) and magnetic resonance imaging(MRI) to localize the lesion in the central nervous system. They were randomly divided into two groups : the control and moxibustion group. Ten of twenty patients underwent moxibustion treatment by randomization. The moxibustion group receieved moxibustion at three points : Chung-guk (Conception Vessel CV3), Kuanwon (CV4) Kihae (CV6). Residual urine volume evaluation was undertaken in all patients. Results : 1. IIn the balanced bladder time, the moxibustion group had the shorter time than non moxibustion group. But there was no significiant difference between the moxibustion group and non-moxibustion group. 2. In the residual urine volume, the moxibustion group and non-moxibustion group showed a tendency to decrease. But there was no significiant difference between the moxibustion group and non-moxibustion group. Conclusions : Though further study is needed, our findings suggested that the time of achieving balanced voiding was shorter with moxibustion than in the control group.

• Journal of Biomedical Engineering Research
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• v.7 no.2
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• pp.113-116
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• 1986

We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies.

• Journal of Korean Neurosurgical Society
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• v.42 no.5
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• pp.413-415
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• 2007

A 26-year-old man was admitted to our department due to intermittent left hemiparesis for 3 months. Magnetic resonance Image showed subacute infarction in the right precentral gyrus. Digital subtraction angiography and magnetic resonance angiography revealed an aneurysmal protrusion at the right middle cerebral artery (MCA) bifurcation. It was difficult to differentiate the aneurysm from the occlusion of the middle trunk of the MCA trifurcation. Brain single photon emission computerized tomography showed a decrease in perfusion in the right posterior frontal lobe without vascular reserve. Therefore, we planned a superficial temporal artery MCA anastomosis with an exploration of the right MCA bifurcation. Intraoperatively, the aneurysmal opacification on preoperative angiography proved to be the proximal stump of the occluded middle trunk of the MCA trifurcation. An aneurysmal protrusion at the MCA bifurcation does not always indicate an aneurysm. In diagnosing protruding vascular lesions at the MCA bifurcation, the possibility of a vascular stump should be considered according to their angioanatomical appearance and the history of the patient.