scholarly journals Learning about reflective PPG for SpO2 determination using Machine Learning

2021 ◽  
Vol 7 (2) ◽  
pp. 33-36
Author(s):  
Idoia Badiola Aguirregomezcorta ◽  
Vladimir Blazek ◽  
Steffen Leonhardt ◽  
Christoph Hoog Antink
Keyword(s):  
Neural Network ◽  
Machine Learning ◽  
Linear Regression ◽  
Oxygen Saturation ◽  
Arterial Oxygen Saturation ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Stochastic Gradient Descent ◽  
Arterial Oxygen ◽  
Peripheral Oxygen Saturation

Abstract Reflective Photoplethysmography (PPG) sensors are less obtrusive than transmissive sensors, but they present patient-dependent variations in the so-called “Ratio of Modulation” (R). Thus, the conventionally employed calibration curves for determining peripheral oxygen saturation ( SpO2) may report inaccurate values. In this paper, we study the possibility of overcoming these limitations through Machine Learning (ML). For that, we show the results of applying several algorithms and feature combinations to PPG data from a human hypoxia study. The study was performed on ten healthy subjects. Their target oxygen saturation was reduced in five steps from 98- 100% to 70-77% through an oral mask. Blood Gas Analysis (BGA) was performed five times for each saturation level to measure the arterial oxygen saturation. PPG data were acquired from a reflective pulse oximeter placed in the subjects’ ear canals. PPG signals were pre-processed, and several features in the frequency and temporal domain were calculated. For the ML algorithms’ input, we explored different combinations of the features. We trained and validated the algorithms with the data from seven patients, and we tested them on three. Finally, we performed leaveone- out cross-validation to ensure the universality of the methods. The results show a good agreement of the predictions with the BGA values for Linear Regression, k- Nearest Neighbors, Stochastic Gradient Descent, and Neural Network for all input feature combinations with an average RMSE in the range of 3%. However, the performance of the Linear Regression was not beaten by the Neural Network, even for overfitting with 2000 hidden layers. The combination of R calculated with a Fast-Fourier Transform and ACRMS.red/ACRMS.irsignificantly improved the results, reducing the RMSE by 25%. This work demonstrates that a straight-forward Linear Regression is capable of determining SpO2with reflective PPG independently of the subject if the ratio ACRMS.red/ACRMS.ir is considered simultaneously with the Ratio of Modulation.

scholarly journals Sequestro Leucocitário de Oxigénio

2016 ◽  
Vol 29 (5) ◽  
pp. 343
Author(s):  
Miguel Pinto da Costa ◽  
Henrique Pimenta Coelho
Keyword(s):  
Oxygen Saturation ◽  
Pulse Oximetry ◽  
Arterial Oxygen Saturation ◽  
Gas Analysis ◽  
Lymphocytic Leukemia ◽  
Red Blood Cell Transfusion ◽  
Clinical State ◽  
Arterial Oxygen ◽  
Low Oxygen ◽  
Arterial Blood

<p>The authors present a case of a 60-year-old male patient, previously diagnosed with B-cell chronic lymphocytic leukemia, who was admitted to the Emergency Room with dyspnea. The initial evaluation revealed severe anemia (Hgb = 5.0 g/dL) with hyperleukocytosis (800.000/µL), nearly all of the cells being mature lymphocytes, a normal chest X-ray and a low arterial oxygen saturation (89%; pulse oximetry). After red blood cell transfusion, Hgb values rose (9.0 g/dL) and there was a complete reversion of the dyspnea. Yet, subsequent arterial blood gas analysis, without the administration of supplemental oxygen, systematically revealed very low oxygen saturation values (~ 46%), which was inconsistent with the patient’s clinical state and his pulse oximetry values (~ 87%), and these values were not corrected by the administration of oxygen via non-rebreather mask. The investigation performed allowed to establish the diagnosis of oxygen leukocyte larceny, a phenomenon which conceals the true oxygen saturation due to peripheral consumption by leukocytes.</p>

scholarly journals Clinical efficacy of combinations of nebulised fluticasone, salbutamol and furosemide on lung function in premature calves with respiratory distress syndrome

2017 ◽  
Vol 62 (No. 10) ◽  
pp. 541-552 ◽  
Author(s):  
R. Yildiz ◽  
M. Ok
Keyword(s):  
Carbon Dioxide ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Oxygen Saturation ◽  
Distress Syndrome ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Control Group ◽  
Peripheral Oxygen Saturation ◽  
Arterial Blood

Surfactant deficiency, poor development of the lung structure and fibrosis as a result of inflammation are thought to play an important role in the development of respiratory distress syndrome in premature calves. Nebulised steroid (fluticasone), bronchodilator (salbutamol) and diuretics (furosemide) can be used in combination alongside standard treatment procedures for premature calves, and might improve viability as observed in infants, foals and horses with pulmonary disorders. Twenty-five premature calves with respiratory distress syndrome were used in this study. Oxygen and supportive treatment were administered to all groups. The first group was used as a control group (Group 1). The nebulised drug combinations were as follows: Group 2: fluticasone + salbutamol, Group 3: salbutamol + furosemide, Group 4: fluticasone + furosemide and Group 5: fluticasone + salbutamol + furosemide. During the 72-h time period of the study, fluticasone (15 µg/kg/12 h), salbutamol (0.025 mg/kg/6 h) and furosemide (1 mg/kg/12h) were applied for 5 min. Arterial blood samples were collected from the auricular artery at 0 h and at 1, 24, 48 and 72 h for blood gas analysis. Significant (P &lt; 0.05) increases in arterial partial oxygen, oxygen saturation and peripheral oxygen saturation and decreases in arterial partial carbon dioxide, lactate and respiration rate were observed in all the nebulised treatment groups, while a statistical difference was observed only for arterial partial carbon dioxide in control group. When comparing the treated groups with the control, it may be concluded that nebulised drugs are highly effective in the therapy of premature calves with respiratory distress syndrome, while the different nebulised groups exhibited similar efficacies.

scholarly journals A Survey to Evaluate the Impact of Ailurophobia on Blood Oxygen Level

2019 ◽  
Vol 4 (2) ◽  
Keyword(s):  
Oxygen Saturation ◽  
Pulse Oximeter ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
P Value ◽  
Blood Oxygen ◽  
Oxygen Level ◽  
Blood Oxygen Level ◽  
Peripheral Oxygen Saturation ◽  
The Impact

The blood oxygen level is a measure of amount of oxygen circulation in the blood. The blood oxygen level test also known as ‘blood gas analysis’ estimates the proper working of the lungs and it performs different measurements. Pulse oximeter, a noninvasive device that helps to detect or estimate the level of carbon dioxide and oxygen saturation in the blood. Normal pulse oximeter reading has a range of 95 to 100 percent. 200 individuals were selected and asked about the fear of cats and their peripheral oxygen saturation was estimated using pulse oximeter device. The results calculated from M Stat software and student’s t-test revealed that there is a significant impact of cat phobia on peripheral oxygen saturation. The calculated p-value was significant depicting the correlation between blood oxygen level and ailurophobia.

scholarly journals Performance of the MP570T pulse oximeter in volunteers participating in the controlled desaturation study: a comparison of seven probes

2020 ◽  
Vol 15 (3) ◽  
pp. 371-377
Author(s):  
Byung-Moon Choi ◽  
Bong Jin Kang ◽  
Ho-Yong Yun ◽  
Bokyoung Jeon ◽  
Ji-Yeon Bang ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Pulse Oximeter ◽  
Breathing Circuit ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Gas Mixture ◽  
Mean Square ◽  
Peripheral Oxygen Saturation ◽  
Hypoxic Gas Mixture ◽  
Finger Probe

Background: The performance of the pulse oximeter was evaluated based on the ISO 80601-2-61:2011 (E) guidelines. This study aimed to determine whether the various finger probes of the MP570T pulse oximeter (MEK-ICS Co., Ltd., Korea) would provide clinically reliable peripheral oxygen saturation (SpO2) readings over a range of 70100% arterial oxygen saturation (SaO2) during non-motion conditions.Methods: Each volunteer (n = 12) was connected to a breathing circuit for the administration of a hypoxic gas mixture. For frequent blood sampling, an arterial cannula was placed in a radial artery. The following seven pulse oximeter probes were simultaneously attached to each volunteer’s fingers: (1) WA-100 reusable finger probe (MEDNIS Co., Ltd., Korea), (2) MDNA disposable finger probe (MEDNIS Co., Ltd.), (3) IS-1011 disposable finger probe (Insung Medical Co., Ltd., Korea), (4) CJ340NA disposable finger probe (CHUN JI IN Medical Co., Ltd., Korea), (5) NellcorTM OxiMax DS-100A reusable finger probe (Medtronic, USA), (6) NellcorTM OxiMax MAX-N disposable finger probe (Medtronic), and (7) OXI-PRO DA disposable finger probe (Bio-Protech Inc., Korea). Results: A total of 275 SpO2-SaO2 pairs were included in the analysis. The accuracy of the root mean square (Arms) of each probe was 2.83%, 3.98%, 3.75%, 6.84%, 3.43%, 5.17%, and 3.84%, respectively.Conclusions: The MP570T pulse oximeter with WA-100 reusable, MDNA disposable, IS-1011 disposable, NellcorTM OxiMax DS-100A reusable, and OXI-PRO DA disposable finger probes meets an acceptable standard of SpO2 accuracy under non-motion conditions.

scholarly journals Exercise peripheral oxygen saturation (Spo2) accurately reflects arterial oxygen saturation (Sao2) and predicts mortality in systemic sclerosis

Thorax ◽  
2009 ◽  
Vol 64 (7) ◽  
pp. 626-630 ◽  
Author(s):  
J J Swigris ◽  
X Zhou ◽  
F S Wamboldt ◽  
R du Bois ◽  
R Keith ◽  
...  
Keyword(s):  
Systemic Sclerosis ◽  
Oxygen Saturation ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Peripheral Oxygen Saturation

Quantitative analysis of the effect of fraction of inspired oxygen on peripheral oxygen saturation in healthy volunteers

2020 ◽  
Author(s):  
Ji-Yeon Bang ◽  
Changhun Cho ◽  
Eun-Kyung Lee ◽  
Byung-Moon Choi ◽  
Gyu-Jeong Noh
Keyword(s):  
Oxygen Saturation ◽  
Acute Hypoxia ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Peripheral Oxygen Saturation ◽  
Turnover Model ◽  
Inhibitory Function ◽  
Short Term Exposure ◽  
Fraction Of Inspired Oxygen ◽  
Inspired Oxygen

Abstract Background The international organization for standardization (ISO) 80601-2-61 dictates that the accuracy of a pulse oximeter should be assessed by a controlled desaturation study. We aimed to characterize the relationship between the fraction of inspired oxygen (FiO 2 ) and peripheral oxygen saturation (SpO 2 ) using a turnover model by retrospectively analyzing the data obtained from previous controlled desaturation studies. We also measured the changes in biomarkers expected to be related to hypoxia (i.e., lactate, carboxyhemoglobin (COHb), and methemoglobin (MetHb)) in response to short-term exposure to hypoxia.Methods Volunteers were exposed to various levels of induced hypoxia over 70−100% arterial oxygen saturation (SaO 2 ). The study period consisted of two rounds of hypoxia and the volunteers were maintained in room air between each round. FiO 2 and SpO 2 were recorded continuously during the study period. A population pharmacodynamic analysis was performed with the NONMEM VII level 4 (ICON Development Solutions, Ellicott City, MD, USA). Lactate, COHb, and MetHb were measured using a CO-oximeter.Results In total, 2899 SpO 2 data points obtained from 20 volunteers were used to determine the pharmacodynamic characteristics. The pharmacodynamic parameters were as follows: k out = 0.942 1/min, Imax = 0.802, IC 50 = 85.3%, γ = 27.3. The changes in SpO 2 due to decreases in FiO 2 well explained by the turnover model with inhibitory function as a sigmoidal model. As SpO 2 decreased, lactate and COHb increased as a whole, and COHb showed the best correlation (Pearson’s correlation, R 2 =0.3263, P < 0.0001).Conclusion The potency of FiO 2 required to reduce SpO 2 from 100% to 70% was 14.7%. Carboxyhemoglobin has the potential to be a useful biomarker for acute hypoxia.

scholarly journals Accuracy of two pulse-oximetry measurements for INTELLiVENT-ASV in mechanically ventilated patients: a prospective observational study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shinshu Katayama ◽  
Jun Shima ◽  
Ken Tonai ◽  
Kansuke Koyama ◽  
Shin Nunomiya
Keyword(s):  
Oxygen Saturation ◽  
Pulse Oximetry ◽  
Prospective Observational Study ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Arterial Blood Gas ◽  
Mechanically Ventilated ◽  
Mechanically Ventilated Patients ◽  
Arterial Blood ◽  
Ventilated Patients

AbstractRecently, maintaining a certain oxygen saturation measured by pulse oximetry (SpO2) range in mechanically ventilated patients was recommended; attaching the INTELLiVENT-ASV to ventilators might be beneficial. We evaluated the SpO2 measurement accuracy of a Nihon Kohden and a Masimo monitor compared to actual arterial oxygen saturation (SaO2). SpO2 was simultaneously measured by a Nihon Kohden and Masimo monitor in patients consecutively admitted to a general intensive care unit and mechanically ventilated. Bland–Altman plots were used to compare measured SpO2 with actual SaO2. One hundred mechanically ventilated patients and 1497 arterial blood gas results were reviewed. Mean SaO2 values, Nihon Kohden SpO2 measurements, and Masimo SpO2 measurements were 95.7%, 96.4%, and 96.9%, respectively. The Nihon Kohden SpO2 measurements were less biased than Masimo measurements; their precision was not significantly different. Nihon Kohden and Masimo SpO2 measurements were not significantly different in the “SaO2 < 94%” group (P = 0.083). In the “94% ≤ SaO2 < 98%” and “SaO2 ≥ 98%” groups, there were significant differences between the Nihon Kohden and Masimo SpO2 measurements (P < 0.0001; P = 0.006; respectively). Therefore, when using automatically controlling oxygenation with INTELLiVENT-ASV in mechanically ventilated patients, the Nihon Kohden SpO2 sensor is preferable.Trial registration UMIN000027671. Registered 7 June 2017.

scholarly journals BIOCHEMICAL STUDIES ON SHOCK

1944 ◽  
Vol 79 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Frank L. Engel ◽  
Helen C. Harrison ◽  
C. N. H. Long
Keyword(s):  
Blood Pressure ◽  
Amino Acids ◽  
Oxygen Saturation ◽  
Hepatic Artery ◽  
Arterial Oxygen Saturation ◽  
Amino Nitrogen ◽  
Arterial Oxygen ◽  
High Positive Correlation ◽  
Peripheral Tissues ◽  
Arterial Blood

1. In a series of rats subjected to hemorrhage and shock a high negative correlation was found between the portal and peripheral venous oxygen saturations and the arterial blood pressure on the one hand, and the blood amino nitrogen levels on the other, and a high positive correlation between the portal and the peripheral oxygen saturations and between each of these and the blood pressure. 2. In five cats subjected to hemorrhage and shock the rise in plasma amino nitrogen and the fall in peripheral and portal venous oxygen saturations were confirmed. Further it was shown that the hepatic vein oxygen saturation falls early in shock while the arterial oxygen saturation showed no alteration except terminally, when it may fall also. 3. Ligation of the hepatic artery in rats did not affect the liver's ability to deaminate amino acids. Hemorrhage in a series of hepatic artery ligated rats did not produce any greater rise in the blood amino nitrogen than a similar hemorrhage in normal rats. The hepatic artery probably cannot compensate to any degree for the decrease in portal blood flow in shock. 4. An operation was devised whereby the viscera and portal circulation of the rat were eliminated and the liver maintained only on its arterial circulation. The ability of such a liver to metabolize amino acids was found to be less than either the normal or the hepatic artery ligated liver and to have very little reserve. 5. On complete occlusion of the circulation to the rat liver this organ was found to resist anoxia up to 45 minutes. With further anoxia irreversible damage to this organ's ability to handle amino acids occurred. 6. It is concluded that the blood amino nitrogen rise during shock results from an increased breakdown of protein in the peripheral tissues, the products of which accumulate either because they do not circulate through the liver at a sufficiently rapid rate or because with continued anoxia intrinsic damage may occur to the hepatic parenchyma so that it cannot dispose of amino acids.

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