• 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.

• Tuberculosis and Respiratory Diseases
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• v.84 no.2
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• pp.125-133
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• 2021

Background: The coronavirus disease (COVID-19) can manifest in a range of symptoms, including both asymptomatic systems which appear nearly non-existent to the patient, all the way to the development of acute respiratory distress syndrome (ARDS). Specifically, COVID-19-associated pneumonia develops into ARDS due to the rapid progression of hypoxia, and although arterial blood gas analysis can assist in halting this deterioration, the current environment provided by the COVID-19 pandemic, which has led to an overall lack of medical resources or equipment, has made it difficult to administer such tests in a widespread manner. As a result, this study was conducted in order to determine whether the levels of oxygen saturation (SpO₂) and the fraction of inhaled oxygen (FiO₂) (SF ratio) can also serve as predictors of ARDS and the patient's risk of mortality. Methods: This was a retrospective cohort study conducted from February 2020 to Mary 2020, with the study's subjects consisting of COVID-19 pneumonia patients who had reached a state of deterioration that required the use of oxygen therapy. Of the 100 COVID-19 pneumonia cases, we compared 59 pneumonia patients who required oxygen therapy, divided into ARDS and non-ARDS pneumonia patients who required oxygen, and then investigated the different factors which affected their mortality. Results: At the time of admission, the ratios of SpO₂, FiO₂, and SF for the ARDS group differed significantly from those of the non-ARDS pneumonia support group who required oxygen (p<0.001). With respect to the predicting of the occurrence of ARDS, the SF ratio on admission and the SF ratio at exacerbation had an area under the curve which measured to be around 85.7% and 88.8% (p<0.001). Multivariate Cox regression analysis identified that the SF ratio at exacerbation (hazard ratio [HR], 0.916; 95% confidence interval [CI], 0.846-0.991; p=0.029) and National Early Warning Score (NEWS) (HR, 1.277; 95% CI, 1.010-1.615; p=0.041) were significant predictors of mortality. Conclusion: The SF ratio on admission and the SF ratio at exacerbation were strong predictors of the occurrence of ARDS, and the SF ratio at exacerbation and NEWS held a significant effect on mortality.

• Journal of Chest Surgery
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• v.16 no.3
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• pp.362-367
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• 1983

Pulmonary arteriovenous fistula is a congenital malformation resulting from errant capillary development, with incomplete formation or disintegration of the vascular septa that normally divide the primitive connections between the venous and arterial plexuses. It generally occurs as part of the disorder known as hereditary hemorrhagic telangiectasia [Rendu-Osler-Weber disease]. The hereditary lesion is transmitted as a simple non-sex-linked dominant trait. It may be single or multiple, too small to see on plain chest films or large and easily recognized. One third of the lesions are multiple on plain chest film. The pathogenesis of its symptoms is that unoxygenated, desaturated arterial blood enters into the pulmonary venous system, directly. Recently we have experienced a case of the pulmonary arteriovenous fistula in 26 years old male soldier, which was confirmed by pulmonary angiography preoperatively. 2 thumb-tip sized, well circumscribed cystic masses filled with bright red colored blood were seen in subpleural and anterolateral portion of the right upper lobe. Right upper Iobectomy was performed due to close approximation of the fistula with pulmonary vein. Microscopically, it shows angiomatous dilatation of the abnormal vessels embedding in the parenchyma. Postoperative physiologic studies show nearly normal arterial oxygen saturation, hemoglobin and RBC count. There was good, uneventful postoperative course.

• Tuberculosis and Respiratory Diseases
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• v.81 no.4
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• pp.319-329
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• 2018

Background: Bronchoalveolar lavage (BAL) is a necessary procedure for diagnosis of various lung diseases. High-flow nasal cannula (HFNC) oxygen delivery was recently introduced. This study aimed to investigate the safety and effectiveness of HFNC oxygen supply during BAL procedure in patients with acute respiratory failure (ARF). Methods: Patients who underwent BAL while using HFNC at a partial pressure of oxygen in arterial blood/fraction of inspired oxygen ($PaO_2/FiO_2$; PF) ratio of 300 or below among patients who had been admitted from March 2013 to May 2017 were retrospectively investigated. Results: Thirty-three BAL procedures were confirmed. Their baseline PF ratio was $166.1{\pm}46.7$. $FiO_2$ values before, during, and after BAL were $0.45{\pm}0.12$, $0.74{\pm}0.19$, and $0.57{\pm}0.14$, respectively. Flow (L/min) values before, during, and after BAL were $26.5{\pm}20.3$, $49.0{\pm}7.2$, and $40.8{\pm}14.2$, respectively. Both $FiO_2$ and flow during and after the procedure were significantly different from those before the procedure (both p<0.001). Oxygen saturation levels before, during, and after BAL measured by pulse oximeter were $94.8{\pm}2.9$, $94.6{\pm}3.5$, and $95.2{\pm}2.8%$, respectively. There were no significant differences in oxygen saturation among the three groups. Complications of BAL procedure included transient hypoxemia, hypotension, and fever. However, there was no endotracheal intubation within 24 hours. Baseline PF ratio in "without HFNC" group was significantly higher than that in "with HFNC" group. There were no differences in complications between the two groups. Conclusion: The use of HFNC during BAL procedure in ARF patients was effective and safe. However, there were no significant differences in oxygen saturation level and complications comparing "without HFNC" group in mild ARF. More studies are needed for moderate to severe ARF patients.

• Journal of Chest Surgery
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• v.29 no.7
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• pp.723-727
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• 1996

An adequate exposure is important in thoracoscopic procedures. The insufflation of $CO_2$has been demonstrated to aid in compressing lung parenchyma, and act as a retractor when combined with changes in patient's position. However, a recent study demonstrated that $CO_2$insufflation during thoracoscopy in the pig has adverse hemodynamic consequences. We prospectively studied 12 patients undergoing thoracoscopy to evaluate the effect of $CO_2$insufflation in the clinical setting. The mean arterial pressure, heart rate, central venous pressure, arterial oxygen saturation, and end-tidal $CO_2$pressure were monitored. Measurements were determined at baseline, at the initiation of one-lung ventilation, and at intrapleural pressure of 5, 10, 15 mmHg and following results were obtained. 1) The insufflation of 5 to 15 mmHg of $CO_2$had no significant effect on the mean arterial pressure, heart rate, arterial oxygen saturation. 2) The end-tidal $CO_2$pressure rose from 31.00$\pm$1.67 mmHg to 38.49$\pm$1.82 mmHg at an intrapleural pressure of 15 mmHg(p<0.05). 3) The central venous pressure rose from 7.75$\pm$0.76 mmHg to 12.83$\pm$1.64 mmHg and 16.16$\pm$l.97mmHg at an intrapleural pressure of 10 and 15 mmHg(p<0.05). 4) The low pressure (<10 mmHg) insufflation is a safe adjunct to the conduct of thoracoscopic surgical procedures.

• Journal of Chest Surgery
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• v.43 no.1
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• pp.104-107
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• 2010

Acute respiratory distress syndrome (ARDS) is difficult to treat and it is often fatal. If the medical treatment for ARDS is not effective, then extracorporeal membrane oxygenation (ECMO) can be applied to the patient. A 22-year-old female who suffered multiple traumatic injuries due to a car accident presented with acute respiratory distress syndrome. Veinarterial extracorporeal membrane oxygenation (VA ECMO) was started to treat her respiratory failure. With the VA ECMO, the systemic oxygen saturation remained at only 84%, and so the ECMO system was switched to V-VA ECMO via an additional venous outflow through the right jugular vein to increase both the systemic and pulmonary oxygen saturation. After conversion to the V-VA type ECMO, the systemic oxygen saturation increased to 94% and the partial pressure of oxygen ($PaO_2$) increased to 65 mmHg. We report here on a successful case of ECMO conversion from the VA type to the V-VA type in a patient with severely hypoxic respiratory failure.

• 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.

• Laboraroty Animal Research
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• v.34 no.4
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• pp.270-278
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• 2018

This study was conducted to compare the anesthetic effects of 2,2,2-tribromoethanol (TBE, $Avertin^{(R)}$) in ICR mice obtained from three different sources. TBE (2.5%) was intraperitoneally injected at three doses: high-dose group (500 mg/kg), intermediate-dose group (250 mg/kg), and low-dose group (125 mg/kg). Anesthesia time, recovery time, end-tidal peak $CO_2$ ($ETCO_2$), mean arterial blood pressure, heart rate, oxygen saturation ($SpO_2$), body temperature, pH, $PCO_2$, and $PO_2$ of the arterial blood were measured. Stable anesthesia was induced by all doses of TBE and the anesthesia time was maintained exhibited dose dependency. No significant differences in anesthetic duration were found among the three different strains. However, the anesthesia time was longer in female than in male mice, and the duration of anesthesia was significantly longer in female than in male mice in the high-dose group. The recovery time was significantly longer for female than male mice in the intermediate- and high-dose groups. In the ICR strains tested, there were no significant differences in the mean arterial blood pressure, $SPO_2$, arterial blood $PCO_2$, and $PO_2$, which decreased after TBE anesthesia, or in heart rate and $ETCO_2$, which increased after TBE anesthesia. In addition, body temperature, blood biochemical markers, and histopathological changes of the liver, kidney, and lung were not significantly changed by TBE anesthesia. These results suggested that ICR mice from different sources exhibited similar overall responses to a single exposure to TBE anesthesia. In conclusion, TBE is a useful drug that can induce similar anesthetic effects in three different strains of ICR mice.

• Journal of Life Science
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• v.13 no.1
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• pp.42-46
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• 2003

Photoplethysmogram is widely used to measure heart rate and arterial blood oxygen saturation in human. This paper describes radial pulse waves recorded by photoplethysmogram with 940 nm wavelength infra red light. Radial pulse waves were varied according to the recording site. When recorded on the skin over radial artery, the radial pulse wave was inverted, comparing to the photoplethysmogram at fingertip. The mechanism of inverted pulse wave seemed to be caused by the change of the blood volume in the subcutaneous tissue between radial artery and the skin, which was reduced during systolic period and increased during diastolic period of the cardiac cycle. These results suggest that radial arterial wall may reflect infra red ray.

• Journal of the Korea Society of Computer and Information
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• v.17 no.3
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• pp.105-111
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• 2012

Photoplethysmogram is widely used to measure heart rate and arterial blood oxygen saturation in human. This paper describes implementation a photoplethysmography monitoring system that uses 780nm and 940nm length infrared light in radial artery. That system used combinations of 8 LEDs and 2 photoelectricities. When recorded on the skin over radial artery, the radial pulse wave was inverted. The mechanism of inverted pulse wave skin, which was reduced during systolic period and increase during diastolic period of the cardiac cycle. Through this system, we discovered optimal environments and combinations of sensors in both penetration type and reflection type. These results suggest that radial arterial wall way reflect infrared ray.