• Journal of Yeungnam Medical Science
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• v.11 no.1
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• pp.49-54
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• 1994

Postoperative brain damage is one of most serious complications of cardiopulmonary bypass (CPB). To prevent brain damage during CPB, adequate cerebral perfusion for cerebral oxygen demand should be maintained. This study monitored jugular venous oxyhemoglobin saturation ($SjO_2$), which reflects the overall balance of cerebral oxygen supply and demand, intermittently in 10 patients undergoing cardiac surgery. At the initiation of CPB, in spite of a significant decrease in mean arterial pressure, $SjO_2$ did not change, and it was stable during the hypothermic period of CPB. But a significan reduction in $SjO_2$ was observed during the rewarming period, and $SjO_2$ had an inverse linear correlation with esophageal temperature. Furthermore, the percent decrease of $SjO_2$ was related to rewarming speed. Therefore, therapeutic approaches for $SjO_2$ desaturation include slower rewarming, increasing cerebral blood flow, decreasing the cerebral metabolic rate for oxygen, increasing oxygen content, and increasing perfusion flow rate.

• Neonatal Medicine
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• v.28 no.1
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• pp.14-21
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• 2021

Purpose: Premature infants have immature respiratory control and cerebral autoregulation. We aimed to investigate changes in cerebral oxygenation during apnea with and without peripheral oxygen desaturation in premature infants. Methods: This prospective observational study was conducted at Inha University Hospital. Near-infrared spectroscopy (NIRS)-monitored regional cerebral oxygen saturation (rScO₂) and pulse oximeter-monitored peripheral oxygen saturation (SpO₂) were assessed during the first week of life in 16 stable, spontaneously breathing preterm infants. Apneic episodes that lasted for ≥20 seconds or were accompanied by desaturation or bradycardia were included for analysis. The average rScO₂ value during the 5-minute prior to apnea (baseline), the lowest rScO₂ value following apnea (nadir), the time to recover to baseline (recovery time), the area under the curve (AUC), and the overshoot above the baseline after recovery were analyzed. Results: The median gestational age and birth weight of the infants were 29.2 weeks (interquartile range [IQR], 28.5 to 30.5) and 1,130 g (IQR, 985 to 1,245), respectively. A total of 73 apneic episodes were recorded at a median postnatal age of 2 days (IQR, 1 to 4). The rScO₂ decreased significantly following apneic episodes regardless accompanied desaturation. There were no differences in baseline, nadir, or overshoot rScO₂ between the two groups. However, the rScO₂ AUC for apnea with desaturation was significantly higher than that for apnea without desaturation. Conclusion: Cerebral oxygenation can significantly decrease during apnea, especially when accompanied by reduced SpO₂. These results add the evidence for the clinical utility of NIRS in monitoring premature infants.

• Tuberculosis and Respiratory Diseases
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• v.67 no.2
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• pp.88-94
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• 2009

Background: From November 2006, The national health insurance system in the Republic of Korea began to cover prescribed long-term oxygen therapy (LTOT) in patients with chronic respiratory insufficiency. This study examined the current status of LTOT after national health insurance coverage. Methods: Between November 1, 2006 and June 30, 2008, the medical records of patients who were prescribed LTOT by chest physicians were reviewed. The data was collected from 13 university hospitals. Results: 197 patients (131 male and 66 female) were prescribed LTOT. The mean age was 64.3${\pm}$13.0 years. The most common underlying disease was chronic obstructive pulmonary disease (n=103, 52.3%). Chest physicians prescribed LTOT using arterial blood gas analysis or a pulse oxymeter (74.6%), symptoms (14%), or a pulmonary function test (11.2%). The mean oxygen flow rate was 1.56${\pm}$0.68 L/min at rest, 2.08${\pm}$0.91 L/min during exercise or 1.51${\pm}$0.75 L/min during sleep. Most patients (98.3%) used oxygen concentrators. Only 19% of patients used ambulatory oxygen supplies. The oxygen saturation before and after LTOT was 83.18${\pm}$10.48% and 91.64${\pm}$7.1%, respectively. After LTOT, dyspnea improved in 81.2% of patients. The mean duration of LTOT was 16.85${\pm}$6.71 hours/day. The rental cost for the oxygen concentrator and related electricity charges were 48,414${\pm}$15,618 won/month and 40,352${\pm}$36,815 won/month, respectively. Approximately 75% of patients had a regular visit by the company. 5.8% of patients had personal pulse oxymetry. 54.9% of patients had their oxygen saturation checked on each visit hospital. 8% of patients were current smokers. The most common complaint with LTOT was the limitation of daily activity (53%). The most common complaint with oxygen concentrators was noise (41%). Conclusion: The patients showed good compliance with LTOT. However, only a few patients used an ambulatory oxygen device or had their oxygen saturation measured.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.1
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• pp.57-66
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• 2024

Objective: Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow obstruction that is only partly reversible, inflammation in the airways, and systemic effects. This study aimed to investigate the association between low peripheral oxygen saturation levels (SpO₂), and composite indices predicting death in male patients with (COPD). Method: A total of 140 participants with post-bronchodilator FEV₁/FVC ratio less than 0.7 were included. Three composite indices (ADO, DOSE, BODEx) were calculated using six variables such as age (A), airflow obstruction (O), body mass index (B), dyspnea (D), exacerbation history (E or Ex), and smoking status (S). Severity of airflow limitation was classified according to Global Initiative for Obstructive Lung Disease (GOLD) guidelines. SpO₂ was measured by pulse oximetry, and anemia and iron deficiency were assessed based on blood hemoglobin levels and serum markers such as ferritin, transferrin saturation, or soluble transferrin receptor. Results: Participants with low SpO₂ (<95%) showed significantly lower levels of %FEV₁ predicted (p=0.020) and %FEV₁/FVC ratio (p=0.002) compared to those with normal SpO₂ levels. The mMRC dyspnea scale (p<0.001) and GOLD grade (p=0.002) showed a significant increase in the low SpO₂ group. Receiver Operating Characteristic analysis revealed higher area under the curve for %FEV₁ (p=0.020), %FEV₁/FVC(p=0.002), mMRC dyspnea scale (p=0.001), GOLD grade (p=0.010), ADO (p=0.004), DOSE (p=0.002), and BODEx (p=0.011) in the low SpO₂ group. Conclusion: These results suggest that low SpO₂ levels are related to increased airflow limitation and the composite indices of COPD.

• Journal of Biomedical Engineering Research
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• v.22 no.5
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• pp.431-438
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• 2001

Oxygen saturation of blood is defined as ratio of total hemoglobins density to oxyhemoglobins density And the accuracy of pulse oxymeter that measures the oxygen saturation of blood by a noninvasive method is influenced by a measuring environment, breathing and motion of patient. Especially when patient moved his arms and fingers, it is difficult to eliminate motion artifact because the motion artifact signal has features that are overlap or closed at normal signal in frequency domain. We propose the filtering method that construct the filter banks and a matched falter to improve the Problem. When experimented by the proposed method, the ratio regulation of the proposed methods has 4.1% below than an adaptive filter (39.7%) and a moving average filter (11.2%). So. the Proposed method will be able to get a stable ratio of SpO2.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.3
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• pp.575-583
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• 2000

Pulse oximetry is a well established non-invasive optical technique for monitoring the $SpO_2$ during anaesthesia, recovery and intensive care. Pulse oximeters determine the oxygen saturation level of blood by measuring the light absorption of arterial blood. In the measurement of the hemoglobin oxygen saturation, conventional method has required the technique of filtering of remove the noise, and of complex signal processing algorithm. So much time have been required to signal processing. In this research, we separate AC signal and DC signal in the stage of signal detection. Therefore we simplify the calculation algorithm for $SpO_2$. The implemented system have the high performance such an accuracy and a processing time than the traditional method.

• The Korean Journal of Pain
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• v.9 no.2
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• pp.374-379
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• 1996

Background: Recently, improvements in drug administration technology have intensified interest in the treatment of postoperative pain. this has resulted in increased use of continuous intravenous infusion of opioid and epidural opioid as alternative to traditional intramuscular administration of opioid. The goal of this study, therefore, was to document the effects of pain control and side effects following continuous intravenous infusion of morphine or meperidine and intramuscular meperidine following cesarean section. Methods: The vital signs, pain score, oxygen saturation and side effects were compared in 150 patients receiving continuous intravenous infusion of morphine, 30 ${\mu}g/kg/hr$ (n=50, group 1); continuous intravenous infusion of meperidine, 150 ${\mu}g/kg/hr$ (n=50, group 2); or intramuscular meperidine, 50mg/every 6hrs (n=50, group 3). Results: VAS (Visual Analogue Scale) was significantly decreased after 30 minutes of administration in all three groups and was significantly lower at 1 hour, but higher at 6 hours in group 3 than two other groups. Severe desaturation episode, defined as $SpO_2$<90%, occurred in the group 3(0.2%). Moderate desaturation episodes, defined as $SpO_2$ 91~95%, occurred more in group 3 than in group 1 and 2 (17.4% vs. 10.4%, 8.2%). The incidence of side effects were similar among three groups. Conclusion: The continuous infusion of opioid was more effective and safe method of postoperative pain control than traditional intramuscular injection.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.4 no.2
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• pp.88-91
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• 2008

A female patient (14 years-old) with mental retardation was scheduled for ambulatory general anesthesia to treat peri-apical abscess and multiple dental caries. She had got cleft palate plasty at 5 years, but there was no past history of difficulty airway during general anesthesia or airway obstruction. Following induction of anesthesia using an inhalational anesthetic technique, conventional naso-tracheal intubation was tried. However, with conventional intubation technique we could not insert tube. And following several trial of intubation with laryngoscope, she developed an upper airway obstruction. Her lungs could not be ventilated using a facial mask and oxygen saturation was decreased. A #3 laryngeal mask airway (LMA) was inserted immediately, which allowed us to ventilate her lungs and restore the oxygen saturation. And dental treatment was carried out under LMA insertion successfully.

• Journal of Biomedical Engineering Research
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• v.38 no.4
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• pp.153-162
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• 2017

The present study proposes a system that can detect sleep-disordered breathing automatically using an air mattress and oxygen saturation. A thin air mattress was fabricated to reduce discomfort during sleep, and respiration signals were acquired. The system was configured to be synchronized with a polysomnography to receive signals simultaneously with other bio-signals. The present study has been conducted with nine adult male and female patients with sleep-disordered breathing, and sleep-disordered breathing events have been detected by applying the signals acquired from the subjects to the rule-based detection algorithm. The sensitivity and positive predictive values were found to evaluate the performance of the system, which are 91.4% and 89.7% for all events, respectively. The comparison of apnea hypopnea index(AHI) between the polysomnography and the proposed method showed squared R-value of 0.9. This study presents the possibility of detecting sleep-disordered breathing at hospitals or homes using the proposed system.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.4
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• pp.772-781
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• 1998

The purpose of this study was to assess the sedative effect of intranasal spray with midazolam for management of the uncooperative 20 children aged from 24 months to 92 months who required extensive treatment. The patients were given randomly a dose of 0.2mg/kg of intranasal placebo, intranasal spray with midazolam, and intranasal drop with midazolam. All the children were restrained in a pediwrap and were monitored with pulse oximeter for assessing the pulse rate and peripheral oxygen saturation. According to Fukuta's behavior rating scale, behavior was checked for evaluation of the clinical sedative effect. The obtained results were as follows: 1. Behavior score of intranasal spray with midazolam was lower than intranasal drop with midazolam(P<0.01). 2. Pulse rate was a significant change as a function of dental procedure(P<0.001), however the peripheral oxygen saturation was not influenced significantly by either adiministration route of drug or dental procedure. Clinically, intranasal spray with midazolam were safe and effective sedation in young children undergoing pediatric dental procedures.