• The Journal of the Society of Korean Medicine Diagnostics
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• v.12 no.1
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• pp.42-62
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• 2008

Objectives: It is well known that some parameters of the photoplethysmogram (PPG) acquired by time domain contour analysis can be used as markers of vascular aging. But the previous studies that have been performed for frequency domain analysis of the PPG to date have provided only restrictive and fragmentary information. The aim of the present investigation was to determine whether the harmonics extracted from the PPG using a fast Fourier transformation could be used as an index of vascular aging. Methods: The PPG was measured in 600 recruited subjects for 30 second durations, To grasp the gross age-related change of the PPG waveform, we grouped subjects according to gender and age and averaged the PPG signal of one pulse cycle. To calculate the conventional indices of vascular aging, we selected the 5-6 cycles of pulse that the baseline was relatively stable and then acquired the coordinates of the inflection points. For the frequency domain analysis we performed a power spectral analysis on the PPG signals for 30 seconds using a fast Fourier transformation and dissociated the harmonic components from the PPG signals. Results: A final number of 390 subjects (174 males and 216 females) were included in the statistical analysis. The normalized power of the harmonics decreased with age and on a logarithmic scale reduction of the normalized power in the third (r=-0.492, P<0.0001), fourth (r=-0.621, P<0.0001) and fifth harmonic (r=-0.487, P<0.0001) was prominent. From a multiple linear regression analysis, Stiffness index, reflection index and corrected up-stroke time influenced the normalized power of the harmonics on a logarithmic scale. Conclusions: The normalized harmonic power decreased with age in healthy subjects and may be less error prone due to the essential attributes of frequency domain analysis. Therefore, we expect that the normalized harmonic power density can be useful as a vascular aging marker.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.1
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• pp.16-25
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• 2012

To calculate the total mass flux that change in dry and flood season in the Yeomha Channel of Gyeonggi Bay, the 13 hour bottom tracking observation was performed from the southern extremity. The value of the total mass flux(Lagrange flux) was calculated as the sum of the Eulerian flux value and stroke drift value and the tidal residual flow was harmonically analyzed through the least-squares method. Moreover, the average during the tidal cycle is essential to calculate the mass flux and the tidal residual flow and there is the need to equate the grid of repeatedly observed data. Nevertheless, due to the great differences in the studied region, the number of vertical grid tends to change according to time and since the horizontal grid differs according to the transport speed of the ship as a characteristic of the bottom tracking observation, differences occur in the horizontal and vertical grid for each hour. Hence, the present study has vertically and horizontally normalized(sigma coordinate) to equate the grid per each hour. When compared to the z-level coordinate system, the Sigma coordinate system was evaluated to have no irrationalities in data analysis with 5% of error. As a result of the analysis, the tidal residual flow displayed the flow pattern of sagging in the both ends in the main waterway direction of dry season. During flood season, it was confirmed that the tidal residual flow was vertical 2-layer flow. As a result of the total mass flux, the ebb properties of 359 cm/s and 261 cm/s were observed during dry and flood season, respectively. The total mass flux was moving the intertidal region between Youngjong-do and Ganghwa-do.

• Sleep Medicine and Psychophysiology
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• v.18 no.2
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• pp.87-94
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• 2011

Objective: OSAS (obstructive sleep apnea syndrome) is a common disorder and its consequences are often serious. It is important to detect the disorder early in the course for proper treatment. This study is to grasp the snoring clinic visitors' knowledge level of OSAS. Method: One hundred and seventy-nine visitors at the of snoring clinic of Seoul National University Hospital were surveyed by questionnaire about reasons of visit and knowledge of treatment methods of snoring and OSAS, diagnostic method, OSAS-related symptoms, and complications. Results: Most of the respondents (89.4%) "have already heard about OSAS" and the major sources of information was the mass media (58.1%) such as television and radio. More than half (60.3%) were aware that snoring is closely related to OSAS. More than half (59.8%) recognized that a nocturnal polysomnograpy was necessary for proper diagnosis. Two thirds (67%) of the respondents noted surgery as a treatment for snoring. More than half (55.9%) answered that they would follow the doctor's advice on the treatment choice. Only 12.3% of respondents "have heard about nCPAP". No one chose nCPAP (nasal continuous positive airway pressure) as a treatment for either snoring or OSAS. About one third (34.6%) of the respondents were aware that OSAS is related to hypertension. Only 12.8% noted that OSAS is related to diabetes mellitus. Conclusion: Visitors at the snoring clinic were found to have substantially limited knowledge of health risks and proper treatments of OSAS. We suggest that it is crucially important to educate patients and offer easy-to-understand information on snoring and OSAS. We predict that provision of educaiton and information to patients and general public will faciliate the diagnosis and treatment of snoring and OSAS and reduce the related disorders such as hypertension, stroke, and diabetes mellitus.

• Journal of Chest Surgery
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• v.38 no.5 s.250
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• pp.349-356
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• 2005

Background: Arterial conduits using in coronary artery bypass grafting (CABG) have been known a great long term patency rates, and improved short and long term clinical outcomes. It has been reported that Off pump CABG has better clinical results than CABG using cardiopulmonary bypass. To evaluate the advantage of arterial conduits over venous conduits and to avoid the adverse effects of cardiopulmonary bypass, we performed total arterial Off pump CABG. Material and Method: From January 2001 to October 2004, Off pump CABG using only arterial conduits was performed on 325 patients with a mean age of $59.3\pm11.9$ years ($36\~83$). Mean ejection fraction was $55.4\pm14.0\%\;(15\~86).$ Angiography showed left main disease or triple-vessel disease in $81.9\%$ of the patients. Indications of using arterial conduits was stenosis $\ge50\%$ of left anterior descending artery, stenosis $\ge80\%$ of branches of left circumflex artery, and stenosis $\ge90\%$ of right coronary artery and its branches. Multi-slice computed tomography was performed on 194 patients to evaluate the short term patency rates. Result: A total of 928 distal anastomoses were performed and the average anastomoses per a patient were $2.86\pm0.78$. There was 1 operative mortality. Postoperative complications were mediastinitis in 6 patients ($1.8\%$), renal failure in 4 patients ($1.2\%$), perioperative myocardial infarction in 3 patients ($0.9\%$), reoperation for bleeding in 3 patients ($0.9\%$). There was no postoperative stroke. Patency rate of arterial conduits was $99.3\%$ (581/585). There were 4 stenoses or competitive flows in 2 radial arteries and 2 right internal mammary arteries. Conclusion: Total arterial Off pump CABG appears to be safe, showing a low surgical mortality and morbidity and excellent short term patency rates of arterial conduits.

• Journal of Chest Surgery
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• v.41 no.1
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• pp.34-40
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• 2008

Background: Off-pump coronary artery bypass grafting (OPCAB) shows fewer side effects than cardiopulmonary by. pass, and other benefits include myocardial protection, pulmonary and renal protection, coagulation, inflammation, and cognitive function. We analyzed the clinical results of our cases of OPCAB. Material and Method: From May 1999 to August 2007, OPCAB was performed in 100 patients out of a total of 310 coronary artery bypass surgeries. There were 63 males and 37 females, from 29 to 82 years old, with a mean age of $62{\pm}10$ years. The preoperative diagnoses were unstable angina in 77 cases, stable angina in 16, and acute myocardial infarction in 7. The associated diseases were hypertension in 48 cases, diabetes in 42, chronic renal failure in 10, carotid artery disease in 6, and chronic obstructive pulmonary disease in 5. The preoperative cardiac ejection fraction ranged from 26% to 74% (mean $56.7{\pm}11.6%$). Preoperative angiograms showed three-vessel disease in 47 cases, two-vessel disease in 25, one-vessel disease in 24, and left main disease in 23. The internal thoracic artery was harvested by the pedicled technique through a median sternotomy in 97 cases. The radial artery and greater saphenous vein were harvested in 70 and 45 cases, respectively (endoscopic harvest in 53 and 41 cases, respectively). Result: The mean number of grafts was $2.7{\pm}1.2$ per patient, with grafts sourced from the unilateral internal thoracic artery in 95 (95%) cases, the radial artery in 62, the greater saphenous vein in 39, and the bilateral internal thoracic artery in 2. Sequential anastomoses were performed in 46 cases. The anastomosed vessels were the left anterior descending artery in 97 cases, the obtuse marginal branch in 63, the diagonal branch in 53, the right coronary artery in 30, the intermediate branch in 11, the posterior descending artery in 9 and the posterior lateral branch in 3. The conversion to cardiopulmonary bypass occurred in 4 cases. Graft patency was checked before discharge by coronary angiography or multi-slice coronary CT angiography in 72 cases, with a patency rate of 92.9% (184/198). There was one case of mortality due to sepsis. Postoperative arrhythmias or myocardial in-farctions were not observed. Postoperative complications were a cerebral stroke in 1 case and wound infection in 1. The mean time of respirator care was $20{\pm}35$ hours and the mean duration of stay in the intensive care unit was $68{\pm}47$ hours. The mean amounts of blood transfusion were $4.0{\pm}2.6$ packs/patient. Conclusion: We found good clinical outcomes after OPCAB, and suggest that OPCAB could be used to expand the use of coronary artery bypass grafting.

• Journal of Nutrition and Health
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• v.53 no.1
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• pp.27-38
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• 2020

Purpose: This study assessed the food intake and nutritional status of the elderly in long-term care facilities in order to provide adequate food services and improve the nutritional status. Methods: The survey was carried out from August 2019 to October 2019 for the elderly in long-term care facilities located in Gwangju Metropolitan City. The survey was conducted to collect data from 199 elderly persons (34 males and 165 females) aged over 65 years old. The food intake was assessed using a 1-day 24-hour recall method. Results: More than 90% of the subjects were over 75 years old. Forty five percent of the subjects were active, 44.2% of the subjects perceived themselves as not being healthy. Dementia and Parkinson's disease were the most common diseases, followed by hypertension, musculo-skeletal disease, diabetes, and stroke. Only 25.6% of the subjects had most of their teeth intact, and 44.7% of the subjects had difficulty in chewing and swallowing. The total food intake was 1,127 g in males and 1,078 g in females. The most frequently consumed foods were kimchi, cooked rice with multi-grains, soybean soup, cooked rice with white rice, yogurt, pumpkin porridge, soy milk, and duck soup. The average energy intake of the subjects was 1,564.9 kcal in males and 1,535.5 kcal in females. The overall nutritional status of the elderly in the long-term care facilities was poor. In particular, the intake of vitamin D and calcium, vitamin C, riboflavin, and potassium were very low. The intake of vitamin D was 5 ㎍, and 86.4% of the elderly were below the estimated average requirement, while the intake of sodium was high. Conclusion: The results of this study can be used to understand the health and nutritional status and to improve the food services and nutrition management for the elderly in longterm care facilities.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.441-446
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• 2009

Background: Side clamping of ascending aorta during proximal graft anastomosis in coronary bypassing surgery in-creases the risk of direct aortic injury as well as embolization of intimal atheroma. Heartstring proximal sealing system (Guidant Corporation, Santa Clara, Calif), developed to avoid aortic side clamping, may minimize risks of such complications. The aim of the current study is to compare the surgical outcomes of the two proximal anastomosis techniquesi.e., Heartstring system versus aortic side clamping in off pump coronary bypassing' surgery (OPCAB). Material and Method: From January 2003 to August 2008, 499 patients underwent OPCAB. Of them, proximal graft anastomosis was performed using Heartstring system in 182 patients (Group I) and conventional manual anastomosis in 317 patients (Group II). The two groups were compared for postoperative major complications and mortality. Result: Two groups showed similar characteristics in terms of preoperative demographic data, left ventricular ejection fraction, renal function and history of diabetes, hypertension and smoking. Although there was no inter-group difference in the history of cerebral ischemia (p=0.48), preoperative brain magnetic resonance angiography revealed greater incidence of severe carotid artery stenosis (>75% of lumen) in the Group I than in the. Group II (44.5% in the Group I and 30.0% in the Group II, p=0.003). There were no inter-group differences in postoperative mortality (p=0.40) and complications (p=0.47) including neurologic events (3 in the Group land 2 in the Group II, p=0.258). Whereas neurologic events all comprised transient ischemic attacks in the Group I, they comprised multiple embolic strokes in the Group II. One patient in the Group II experienced aortic dissection during proximal anastomosis which resulted in ascending aortic replacement. Conclusion: Although proximal anastomosis using Heartstring system did not show statistically significant benefit over aortic side clamping, the. absence of embolic stroke maybe a definite benefit which may be better defined through further studies over a larger cohort.

• Progress in Medical Physics
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• v.16 no.4
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• pp.207-213
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• 2005

The severity of carotid Intima-media thickness (IMT) is an Independent predictor of atherosclerosis which causes transient cerebral ischemia, stroke, and coronary events such as myocardial Infarction. The IMT consists of Intima thickness (IT) and media thickness (MT). However, the Individual clinical significance of IT and MT has not been well studied. We devised a method of measuring IT, MT, and IMT using B-mode ultrasound Image processing technique for the diagnosis of atherosclerosis. To inspect the clinical significance of IT, MT, and IMT, one hundred forty-four consecutive patients (mean age; 57 years old, 72 males) were underwent common carotid artery scanning using high-resolution ultrasound. Results showed that, the IT (p<0.05), MT (p<0.05) as well as IMT (p<0.01) of patients with atherosclerotic disease were significantly thicker than that of the patients without atherosclerotic disease. Patients with hyperiension showed significantly thicker IT (p<0.01), MT (p<0.001), and IMT (p<0.001). However, only IT was thicker in patients with smoking (p<0.01). The IT (r=0.374, p=0.001), MT (r=0.433, p=0.000), and IMT (r=0.479, p=0.000) showed positive correlation with age. The coefficients of determination ($r^2$) were estimated to be $92.4\%$ for IMT and MT, $49.1\%$ for IMT and IT, and $27.4\%$ for IT and MT. This result suggests that the Intima layer of the carotid artery has a different physiology with the media layer.

• Journal of Chest Surgery
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• v.41 no.1
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• pp.41-48
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• 2008

Background: Accurate assessment of the preload and the fluid responsiveness is of great importance for optimizing cardiac output, especially in those patients with coronary artery occlusive disease (CAOD). In this study, we evaluated the relationship between the parameters of preload with the changes in the stroke volume index (SVI) after fluid loading in patients who were undergoing coronary artery bypass grafting (CABG). The purpose of this study was to find the predictors of fluid responsiveness in order to assess the feasibility of using. certain parameters of preload as a guide to fluid therapy. Material and Method: We studied 96 patients who were undergoing CABG. After induction of anesthesia, the hemodynamic parameters were measured before (T1) and 10 min after volume replacement (T2) by an infusion of 6% hydroxyethyl starch 130/0.4 (10 mL/kg) over 20 min. Result: The right ventricular end-diastolic volume index (RVEDVI), as well as the central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP), failed to demonstrate significant correlation with the changes in the SVI (%). Only the right ventricular ejection fraction (RVEF) measured at T1 showed significant correlation. with the changes of the SVI by linear regression (r=0.272, p=0.017). However, when the area under the curve of receiver operating characteristics (ROC) was evaluated, none of the parameters were over 0.7. The volume-induced increase in the SVI was 10% or greater in 31 patients (responders) and under 10% in 65 patients (non-responders). None of the parameters of preload measured at T1 showed a significant difference between the responders and non-responders, except for the RVEF. Conclusion: The conventional parameters measured with a volumetric pulmonary artery catheter failed to predict the response of SVI following fluid administration in patients suffering with CAOD.

• The Journal of Korean Medicine
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• v.18 no.1
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• pp.5-24
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• 1997

Clinical observation was made on 226 cases of CVA that were confirmed through brain CT, MRI scan and clinical observation. They were hospitalized in the oriental medical hospital of Kyung-Won University from January to December in 1995. 1. The CVA cases were classified into the following kinds: cerebral infarction, cerebral hemorrhage, subarachnoid hemorrhage(SAH), transient ischemic attack, and the greatest in number among them were the cases of cerebral infarction. 2. The frequency of strokes was much the same between male and female cases and most cases were over 50 of age. 3. In the case of cerebral infarction the place of the most frequent occurrences was in the MCA territory, and as for cerebral hemorrhage, in the basal ganglia area. 4. The most ordinary preceding disease was hypertension. The next was diabetes mellitus. 5. Generally it is thought that CVA occurs frequently in winter. But on the contrary this study of observation confirmed that it occurs mostly in spring and summer. 6. The predisposing factors of cerebral infarction were usually initiated during the time of resting and sleeping and those of cerebral hemorrhage chiefly during the time of exercising. 7. As concerns the course of hospitalization, most patients passed through vestern medical hospitals or oriental medical hospitals. 8. For the patients the condition of whose consciousness was bad at the time of admission. the prognosis in most cases was bad. 9. The common symptoms were motor disability and verbal disturbance. 10. With regard to cerebral infarction, the average time to start physical theraphy was 6.4 days and with cerebral hemorrhage 9.7 days after stroke. 11. The duration of hospitalization was in most cases more than one month. 12. The main complication was urinary tract infection. 13. At the time of admission to hospital, the blood pressure in most cases was high, but it well controlled at the time of discharge. 14. Most cases were given simultaneous treatment in both ways of western and oriental medicine.