• 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.

• The Korean Journal of Nuclear Medicine
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• v.26 no.1
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• pp.49-57
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• 1992

혈관확장제 투여에 의한 약물부하 심근스캔시는 운동부하 심근스캔시와 비교하여 심박출량과 관상 동백 혈류의 증가정도가 달라서 심근내 T1-201의 농도가 달라진다. 그러므로 부하 심근관류스캔의 정량적 판독시에 각각의 부하에 특이적인 Normal file을 사용하지 않으면 이러한 심근내 T1-201 농도의 차이로 인하여 관류 결손의 크기가 다르게 나타날 수 있으리라 추측할 수 있다. 본 연구는 좌전하행지의 유의한 협착이 있는 34명의 단일 혈관 관상동맥 환자에서 이러한 가정이 실제적으로 어떻게 나타나는가를 조사하였다. 환자들은 adenosine 140ug/kg/min을 정맥주사하고 T1-201 SPECT를 실시하였다. 관류결손의 크기는 답차운동부하 T1-201 스캔을 실시한 정상인에서 구한 Normal File (File-ex)과 adenosine T1-201 스캔의 Normal File (File-ad)을 각각 이용하여 만든 극성지도에서 구한 adenosine 심근스캔의 관류결손의 범위지수(extent score)와 중증도지수(severity score)로 표시하였고, 이들의 값을 비교하여 아래의 결과를 얻었다. File-ex로 구한 관류결손의 범위지수는 $19{\pm}13%$였고 File-ad로 구한 범위는 $11{\pm}10%$였다(차이 $8.1{\pm}1.6%$, p=0.0001), 중증도지수는 File-ex를 사용하였을 때 $582{\pm}479$였고 File-ad를 사용하였을때는 $310{\pm}309$였다(차이 $272{\pm}49$, p<0.0001). $50\sim70%$의 중등도의 내경 협착이 있었던 20명의 환자에서는 범위지수는 File-ex와 File-ad에서 각각 $17{\pm}10$과 $7{\pm}7%$(p=0.001)였고, 70% 이상의 내경 협착이 있었던 14명에서의 범위 지수는 각각 $24{\pm}16$과 $18{\pm}10%$ (p=0.03)로 모두에서 File-ex를 사용하였을때의 값이 컸다. 이와 같은 성적으로 보아 T1-201 스핀에서 관류결손의 정도를 정량적으로 첨가할 시에는 부하에 특이적인 Normal File을 사용하여야 관류 결손의 정도를 정확하게 추출할 수 있다는 사실을 알 수가 있다. 즉 dipyridamole이나 adenosine부하경사에서 운동부하의 Normal File을 사용하면 관류결손의 정도가 과대평가 된다는 것이다.

• Journal of Chest Surgery
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• v.41 no.2
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• pp.210-215
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• 2008

Background: Drug-eluting stents are contributing to the exponential growth of percutaneous coronary intervention, and even in the patients with left main coronary artery disease, owing to the decreased restenosis rate. Our study aimed at comparing the one-year results after coronary artery bypass grafting versus percutaneous coronary intervention with drug-eluting stents in patients with left main coronary artery disease. Material and Method: Those patients who underwent coronary bypass surgery or stenting at our hospital under the diagnosis of left main coronary artery disease were divided in two groups. The variables for comparison were the preoperative disease severity, the length of the hospital stay, the early mortality and the cumulative incidence of mortality, myocardial infarction and repeated revascularization. Result: There were 101 cases in the surgery group and 78 cases in the stent group. Age, gender, the risk factors, the left ventricular ejection fraction and the proportion of acute coronary syndrome showed no significant differences between the two groups. The surgery group showed a more severe condition according to the Euroscore, a greater incidence of urgency, a longer hospital stay and a greater incidence of multi-vessel disease. The early mortality and one-year cumulative mortality were not different between the groups. The Euroscore-matched comparison for the surgery group (41 patients) and the stent group (78 patients) showed no significant differences in the Euroscore, age, gender, risk factors and the proportion of acute coronary syndrome. The surgery group in the Euroscore-matched comparison showed more multi-vessel disease and a longer hospital stay. The surgery group showed lower early mortality and lower one-year cumulative mortality, but this was statistically insignificant (0% vs 2.6%, respectively, p=0.55; 0% vs 6.6%, respectively, p=0.30). The rates of repeated revascularization and major adverse events (death or myocardial infarct) were lower in the CABG group, but this was not statistically significant (13.3% vs 6.3%, respectively, p=0.48; 10.0% vs 0%, respectively, p=0.09). Conclusion: Percutaneous coronary intervention using drug-eluting stents in low-risk patients with left main coronary artery disease resulted in a shortened length of the hospital stay, as compared with that of the CABG group of patients. However, the patients who underwent percutaneous coronary intervention using drug-eluting stents showed a tendency for an increased rate of repeated revascularization and higher one-year cumulative mortality. Further studies with large populations and longer follow-up will be necessary to reaffirm our findings.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.1
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• pp.75-79
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• 2019

Purpose Cadmium-zinc-telluride (CZT) camera with semiconductor detector is capable of dynamic myocardial perfusion SPECT for coronary flow reserve (CFR). Image acquisition with the heart positioned within 2 cm in the center of the quality field of view (QFOV) is recommended because the CZT detector based on focused multi-pinhole collimators and is stationary gantry without rotation. The aim of this study was to investigate the optimal method for measuring position of the heart within the center of the QFOV when performing dynamic myocardial perfusion SPECT with the Discovery NM 530c camera. Materials and Methods From June to September 2018, 45 patients were subject to dynamic myocardial perfusion SPECT with D530c. For accurate heart positioning, the patient's heart was scanned with a mobile ultrasound and marked at the top of the probe where the mitral valve (MV) was visible in the parasternal long-axis view (PLAX). And, the marked point on the patient's body matched with the reference point indicated CZT detector in dynamic stress. The heart was positioned to be in the center of the QFOV in rest. The coordinates of dynamic stress and rest were compared statistically. Results The coordinates of the dynamic stress using mobile ultrasound and those taken of the rest were recorded for comparative analysis with regard to the position of the couch and analyzed. There were no statistically significant differences in the coordinates of Table in & out, Table up & down, and Detector in & out (P > 0.05). The difference in distance between the 2 groups was measured at $0.25{\pm}1.00$, $0.24{\pm}0.96$ and $0.25{\pm}0.82cm$ respectively, with no difference greater than 2 cm in all categories. Conclusion The position of the heart taken using mobile ultrasound did not differ significantly from that of the center of the QFOV. Therefore, The use of mobile ultrasound in dynamic stress will help to select the correct position of the heart, which will be effective in clinical diagnosis by minimizing the image quality improvement and the patient's exposure to radiation.

• Journal of Chest Surgery
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• v.21 no.5
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• pp.842-849
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• 1988

Between July, 1987, and September, 1988, 6 patients with coronary occlusive disease received coronary artery bypass surgery at Kyungpook University Hospital. There were five males and one female whose age ranged from 39 to 64 years[mean 54*8.0 years]. Of the 6 patients, 5 suffered from unstable angina, 1 suffered from stable angina. Selective coronary angiography revealed a significant stenosis of the left anterior descending artery in 6 cases, of its diagonal branch in 1 case, of the right coronary artery in 1 case, the circumflex artery in 1 case, and of its obtuse marginal branch in 1 case. The mode of anastomosis were single saphenous vein graft in 3 cases, single left internal mammary artery graft in 1 case, double saphenous vein graft with sequential anastomosis in 1 case, and left internal mammary artery plus saphenous vein graft in 1 case. Of these, 6 grafts to left anterior descending artery were done. There was no operative death, but perioperative myocardial infarction was happened in 1 case. All survivors were free of angina and discontinuing medical therapy during the follow up period[mean 7.8*5.15 months].

• Journal of Chest Surgery
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• v.27 no.6
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• pp.472-476
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• 1994

The incidence of single coronary artery is extremely rare in a review of congenital anomalies of the coronary arteries. This 27-year-old male patient was referred for the evaluation of cardiac condition showing exertional dyspnea[NYHA class II-III] and chest discomfort for about 1 year. A complete catheterization study including angiogram disclosed large single coronary artery arising from left aortic sinus [Ogden classification L-4] associated with bicuspid aortic valvular stenosis and low grade supravalvular aortic stenosis. Calcified stenotic aortic valve was fully removed with caution and the 19mm St. Jude Medical valve was then implanted in the small nortic annulus. The patient had an uneventful recovery and was discharged on 13th postoperative day.

• Journal of Chest Surgery
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• v.32 no.4
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• pp.373-378
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• 1999

Background: Minimally invasive technique for various cardiac surgeries has become widely accepted since it has been proven to have distinct advantages for the patients. We describe here the results of our experiences of minimal incision in cardiac surgery. Material and Method: From February 1997 to November 1998, we successfully performed 31 cases of minimally invasive cardiac surgery. Male and female ratio was 17:14, and the patients age ranged from 1 to 75 years. A left parasternal incision was used in 9 patients with single vessel coronary heart disease. A direct coronary bypass grafting was done under the condition of the beating heart without cardiopulmonary bypass support(MIDCAB). Among these, one was a case of a reoperation 1 week after the first operation due to a kinked mammary artery graft. A right parasternal incision was used in one case of a redo mitral valve replacement. Mini-sternotomy was used in the remaining 21 patients. The procedures were mitral valve replacement and tricuspid annuloplasty in 6 patients, mitral valve replacement 5, double valve replacement 2, aortic valve replacement 1, removal of left atrial myxoma 1, closure of atrial septal defect 2, repair of ventricular septal defect 2, and primary closure of r ght ventricular stab wound 1. The initial 5 cases underwent a T-shaped mini-sternotomy, however, we adopted an arrow-shaped ministernotomy in the remaining cases because it provided better exposure of the aortic root and stability of the sternum after a sternal wiring. Result: The operation time, the cardiopulmonary bypass time, the aorta cross-clamping time, the mechanical ventilation time, the amount of chest tube drainage until POD#1, the chest tube indwelling time, and the duration of intensive care unit staying were in an acceptable range. There were two surgical mortalities. One was due to a rupture of the aorta cannulation site after double valve replacement on POD#1 in the mini-sternotomy case, and the other was due to a sudden ventricular arrhythmia after MIDCAB on POD#2 in the parasternal incision case. Postoperative complications were observed in 2 cases in which a cerebral embolism developed on POD#2 after a mini-sternotomy in mitral valve replacement and wound hematoma developed after a right parasternal incision in a single coronary bypass grafting. Neither mortality nor complication was directly related to the incision technique itself. Conclusion: Minimally invasive surgery using parasternal or mini-sternotomy incision can be used in cardiac surgeries since it is as safe as the standard full sternotomy incisions.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.611-618
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• 2006

Background: There have been controversies whether mitral valvular surgery is necessary in the patients with moderate ischemic mitral regurgitation undergoing coronary artery bypass grafting. The purpose of this study is to evaluate the long term clinical results of patients with moderate ischemic mitral regurgitation. Material and Method: Between January 1992 and February 2005, 44 patients with moderate ischemic mitral regurgitation underwent coronary artery bypass grafting. Concomitant mitral valvular procedure was performed in 20 patients (group 1) and isolated coronary artery bypass grafting was performed in 24 patients (group 2). There were no significant difference between groups except cardiopulmonary bypass time (p<0.01). Postoperative follow up duration was $30.1{\pm}29.6$ months and last follow up echocardiographic examination was performed at $21.2{\pm}28.0$ months. Result: There was no difference in operative mortality between groups (group 1 vs group 2, 15.0% vs 8.3%, p=0.493). Grade of mitral regurgitation ${(0.81{\pm}0.91\;vs\;1.50{\pm}0.05,\;p=0.046)}$ and reduction in regurgitation grade ${(1.75{\pm}0.93\;vs\;0.70{\pm}1.26,\;p=0.009)}$ were different between two groups. But there were no significant differences in left ventricular ejection fraction ${(34.1{\pm}11.4%\;vs\;41.6{\pm}12.9%)}$, left ventricular end systolic volume ${(118.2{\pm}63.9\;ml%\;vs\;85.6{\pm}281\;ml)}$, New York Heart Association functional class ${(2.1{\pm}0.2\;vs\;2.4{\pm}1.2)}$ and 5 year survival rate ${(85{\pm}8%\;vs\;82{\pm}8%)}$. There was no risk factor for operative mortality and the only risk factor for late death was preoperative atrial fibrillation (p=0.042). There was no significant correlation between mitral valvular surgery and late death. Conclusion: Concomitant mitral valvular procedure in patients with moderate ischemic mitral regurgitation undergoing coronary artery bypass grafting had no significant positive effect on survival and ventricular function compared with isolated coronary artery bypass grafting. Prospective randomized study may be needed to evaluate the necessity of concomitant mitral procedure and to find more effective method for the improvement of ventricular function.

• The Journal of the Korea Contents Association
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• v.12 no.7
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• pp.273-283
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• 2012

Drug-eluting stents (DES) have significantly reduced in-stent restenosis, compared to bare-metal stents (BMS). However, there remains concern for the increased risk of stent thrombosis (ST) associated with DES. The present study sought to evaluate the incidence, clinical characteristics and outcome of ST in patients with acute myocardial infarction (MI) during a 1-year follow-up. 80 patients who developed ST were divided into 2 groups according to stent type: group I (DES-ST, n = 57 ) and group II (BMS-ST, n = 23 ). There were no differences between group I and II in the overall incidence of ST (2.7% vs. 4.3%, p=0.064) and in the incidence of each type of ST: acute ST (8.8% vs. 2.3%), subacute ST (50.9% vs. 60.9%), late ST (19.3% vs. 8.7%), and very late ST (21.1% vs. 17.4%) (p=0.605). Predictors of 1-year mortality were the occurrence of ST (OR 8.12, 95% CI 2.83-23.61, p<0.001), left ventricular ejection fraction<40% (OR 6.41, 95% CI 2.42-16.96, p<0.001), and age${\geq}$75 years (OR 4.98, 95% CI 1.95-12.74, p=0.001).

• Journal of Yeungnam Medical Science
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• v.18 no.2
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• pp.215-225
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• 2001

Background: There are many evidences that inflammation is an important determinant of the development of atherosclerosis and one of the systemic markers of inflammation, C-reactive protein(CRP), is associated with extent of coronary artery disease and risk of coronary events. We assessed the time response of CRP response after coronary angioplasty and it's influence on the clinical restenosis in angina patients. Materials and Methods: Patients included 36 angina patients undergoing single vessel angioplasty. Levels of CRP were measured before and 12, 24, 48, and 72 hours after angioplasty. Clinical restenosis was assessed at 6 months after procedure. Results: Baseline CRP level was $0.30{\pm}0.01$ mg/dL in stable and $0.46{\pm}0.28$ mg/dL in unstable angina patients(p<0.05). After angioplasty, CRP level was increased with peak at 24 hour and persisted to 72 hours after angioplasty. At 24 hour after angioplasty, the magnitude of CRP change was $0.32{\pm}0.31$ mg/dL in stable and $0.79{\pm}0.73$ mg/dL in unstable angina patient(p<0.05). The change of CRP level was not associated with troponin-T after angioplasty. In unstable angina patients, clinical restenosis was developed in 8% of patients with low baseline CRP levels and in 50% of those with high baseline CRP levels more than 0.6 mg/dL(p<0.05). Conclusion: In unstable angina patients, inflammatory response is more increased than stable angina patients, and increased inflammatory response effects on the restenosis after coronary angioplasty.