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Katsuyuki Miyasaka - One of the best experts on this subject based on the ideXlab platform.
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Multiwavelength Pulse Oximetry: Theory for the Future
Anesthesia & Analgesia, 2007Co-Authors: Takuo Aoyagi, Masayoshi Fuse, Naoki Kobayashi, Kazuko Machida, Katsuyuki MiyasakaAbstract:BACKGROUND:As the use of pulse oximeters increases, the needs for higher performance and wider applicability of pulse Oximetry have increased. To realize the full potential of pulse Oximetry, it is indispensable to increase the number of optical wavelengths. To develop a multiwavelength Oximetry sys
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Multiwavelength pulse Oximetry: theory for the future.
Anesthesia and analgesia, 2007Co-Authors: Takuo Aoyagi, Masayoshi Fuse, Naoki Kobayashi, Kazuko Machida, Katsuyuki MiyasakaAbstract:As the use of pulse oximeters increases, the needs for higher performance and wider applicability of pulse Oximetry have increased. To realize the full potential of pulse Oximetry, it is indispensable to increase the number of optical wavelengths. To develop a multiwavelength Oximetry system, a physical theory of pulse Oximetry must be constructed. In addition, a theory for quantitative measurement of optical absorption in an optical scatterer, such as in living tissue, remains a difficult theoretical and practical aspect of this problem. We adopted Schuster's theory of radiation through a foggy atmosphere for a basis of theory of pulse Oximetry. We considered three factors affecting pulse Oximetry: the optics, the tissue, and the venous blood. We derived a physical theoretical formula of pulse Oximetry. The theory was confirmed with a full SO2 range experiment. Based on the theory, the three-wavelength method eliminated the effect of tissue and improved the accuracy of Spo2. The five-wavelength method eliminated the effect of venous blood and improved motion artifact elimination. Our theory of multiwavelength pulse Oximetry can be expected to be useful for solving almost all problems in pulse Oximetry such as accuracy, motion artifact, low-pulse amplitude, response delay, and errors using reflection Oximetry which will expand the application of pulse Oximetry. Our theory is probably a rare case of success in solving the difficult problem of quantifying optical density of a substance embedded in an optically scattering medium.
Robert G. Hahn - One of the best experts on this subject based on the ideXlab platform.
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Accuracy of noninvasive haemoglobin measurement by pulse Oximetry depends on the type of infusion fluid.
European journal of anaesthesiology, 2013Co-Authors: Christian Bergek, Joachim Zdolsek, Robert G. HahnAbstract:Context: Measurement of blood haemoglobin concentration by pulse Oximetry could be of value in determining when erythrocytes should be transfused during surgery, but the effect of infusion fluids on the results is unclear.Objective: To study the effect of crystalloid and colloid fluid on the accuracy (bias) and precision of pulse Oximetry haemoglobin estimation to indicate the venous haemoglobin concentration in volunteers.Design: Open interventional crossover study.Setting: Single university hospital.Participants: Ten male volunteers aged 18–28 (mean 22) years.Interventions: Each volunteer underwent three infusion experiments on separate days and in random order. The infusions were Ringer's acetate (20 ml kg−1), hydroxyethyl starch 130/0.4 (10 ml kg−1) and a combination of both.Results: At the end of the infusions of Ringer's acetate, pulse Oximetry haemoglobin concentration had decreased more than the true haemoglobin concentration (15 vs. 8%; P < 0.005; n = 10) whereas starch solution decreased pulse Oximetry haemoglobin concentration less than true haemoglobin concentration (7 vs. 11%; P < 0.02; n = 20). The same differences were seen when the fluids were infused separately and when they were combined. The overall difference between all 956 pairs of pulse Oximetry haemoglobin concentration and true haemoglobin concentrations (the bias) averaged only −0.7 g l−1 whereas the 95% prediction interval was wide, ranging from −24.9 to 23.7 g l−1. In addition to the choice of infusion fluid, the bias was strongly dependent on the volunteer (each factor, P < 0.001).Conclusion: The bias of measuring haemoglobin concentration by pulse Oximetry is dependent on whether a crystalloid or a colloid fluid is infused.
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Accuracy of noninvasive haemoglobin measurement by pulse Oximetry depends on the type of infusion fluid.
European journal of anaesthesiology, 2012Co-Authors: Christian Bergek, Joachim Zdolsek, Robert G. HahnAbstract:Measurement of blood haemoglobin concentration by pulse Oximetry could be of value in determining when erythrocytes should be transfused during surgery, but the effect of infusion fluids on the results is unclear. To study the effect of crystalloid and colloid fluid on the accuracy (bias) and precision of pulse Oximetry haemoglobin estimation to indicate the venous haemoglobin concentration in volunteers. Open interventional crossover study. Single university hospital. Ten male volunteers aged 18-28 (mean 22) years. Each volunteer underwent three infusion experiments on separate days and in random order. The infusions were Ringer's acetate (20 ml kg), hydroxyethyl starch 130/0.4 (10 ml kg) and a combination of both. At the end of the infusions of Ringer's acetate, pulse Oximetry haemoglobin concentration had decreased more than the true haemoglobin concentration (15 vs. 8%; P < 0.005; n = 10) whereas starch solution decreased pulse Oximetry haemoglobin concentration less than true haemoglobin concentration (7 vs. 11%; P < 0.02; n = 20). The same differences were seen when the fluids were infused separately and when they were combined. The overall difference between all 956 pairs of pulse Oximetry haemoglobin concentration and true haemoglobin concentrations (the bias) averaged only -0.7 g l whereas the 95% prediction interval was wide, ranging from -24.9 to 23.7 g l. In addition to the choice of infusion fluid, the bias was strongly dependent on the volunteer (each factor, P < 0.001). The bias of measuring haemoglobin concentration by pulse Oximetry is dependent on whether a crystalloid or a colloid fluid is infused. Trial registration ClinicalTrials identifier: NCT01195025.
Scott D Grosse - One of the best experts on this subject based on the ideXlab platform.
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role of pulse Oximetry in examining newborns for congenital heart disease a scientific statement from the american heart association and american academy of pediatrics
Circulation, 2009Co-Authors: William T Mahle, Robert Koppel, Jane W Newburger, Paul G Matherne, Frank C Smith, Tracey R Hoke, Samuel S Gidding, Robert H Beekman, Scott D GrosseAbstract:Background— The purpose of this statement is to address the state of evidence on the routine use of pulse Oximetry in newborns to detect critical congenital heart disease (CCHD). Methods and Results— A writing group appointed by the American Heart Association and the American Academy of Pediatrics reviewed the available literature addressing current detection methods for CCHD, burden of missed and/or delayed diagnosis of CCHD, rationale of Oximetry screening, and clinical studies of Oximetry in otherwise asymptomatic newborns. MEDLINE database searches from 1966 to 2008 were done for English-language papers using the following search terms: congenital heart disease, pulse Oximetry, physical examination, murmur, echocardiography, fetal echocardiography, and newborn screening. The reference lists of identified papers were also searched. Published abstracts from major pediatric scientific meetings in 2006 to 2008 were also reviewed. The American Heart Association classification of recommendations and levels of evidence for practice guidelines were used. In an analysis of pooled studies of Oximetry assessment performed after 24 hours of life, the estimated sensitivity for detecting CCHD was 69.6%, and the positive predictive value was 47.0%; however, sensitivity varied dramatically among studies from 0% to 100%. False-positive screens that required further evaluation occurred in only 0.035% of infants screened after 24 hours. Conclusions— Currently, CCHD is not detected in some newborns until after their hospital discharge, which results in significant morbidity and occasional mortality. Furthermore, routine pulse Oximetry performed on asymptomatic newborns after 24 hours of life, but before hospital discharge, may detect CCHD. Routine pulse Oximetry performed after 24 hours in hospitals that have on-site pediatric cardiovascular services incurs very low cost and risk of harm. Future studies in larger populations and across a broad range of newborn delivery systems are needed to determine whether this practice should become standard of care in the routine assessment of the neonate.
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role of pulse Oximetry in examining newborns for congenital heart disease a scientific statement from the aha and aap
Pediatrics, 2009Co-Authors: William T Mahle, Robert Koppel, Jane W Newburger, Paul G Matherne, Frank C Smith, Tracey R Hoke, Samuel S Gidding, Robert H Beekman, Scott D GrosseAbstract:BACKGROUND: The purpose of this statement is to address the state of evidence on the routine use of pulse Oximetry in newborns to detect critical congenital heart disease (CCHD). METHODS AND RESULTS: A writing group appointed by the American Heart Association and the American Academy of Pediatrics reviewed the available literature addressing current detection methods for CCHD, burden of missed and/or delayed diagnosis of CCHD, rationale of Oximetry screening, and clinical studies of Oximetry in otherwise asymptomatic newborns. MEDLINE database searches from 1966 to 2008 were done for English-language papers using the following search terms: congenital heart disease, pulse Oximetry, physical examination, murmur, echocardiography, fetal echocardiography, and newborn screening. The reference lists of identified papers were also searched. Published abstracts from major pediatric scientific meetings in 2006 to 2008 were also reviewed. The American Heart Association classification of recommendations and levels of evidence for practice guidelines were used. In an analysis of pooled studies of Oximetry assessment performed after 24 hours of life, the estimated sensitivity for detecting CCHD was 69.6%, and the positive predictive value was 47.0%; however, sensitivity varied dramatically among studies from 0% to 100%. False-positive screens that required further evaluation occurred in only 0.035% of infants screened after 24 hours. CONCLUSIONS: Currently, CCHD is not detected in some newborns until after their hospital discharge, which results in significant morbidity and occasional mortality. Furthermore, routine pulse Oximetry performed on asymptomatic newborns after 24 hours of life, but before hospital discharge, may detect CCHD. Routine pulse Oximetry performed after 24 hours in hospitals that have on-site pediatric cardiovascular services incurs very low cost and risk of harm. Future studies in larger populations and across a broad range of newborn delivery systems are needed to determine whether this practice should become standard of care in the routine assessment of the neonate.
Takuo Aoyagi - One of the best experts on this subject based on the ideXlab platform.
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Multiwavelength Pulse Oximetry: Theory for the Future
Anesthesia & Analgesia, 2007Co-Authors: Takuo Aoyagi, Masayoshi Fuse, Naoki Kobayashi, Kazuko Machida, Katsuyuki MiyasakaAbstract:BACKGROUND:As the use of pulse oximeters increases, the needs for higher performance and wider applicability of pulse Oximetry have increased. To realize the full potential of pulse Oximetry, it is indispensable to increase the number of optical wavelengths. To develop a multiwavelength Oximetry sys
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Multiwavelength pulse Oximetry: theory for the future.
Anesthesia and analgesia, 2007Co-Authors: Takuo Aoyagi, Masayoshi Fuse, Naoki Kobayashi, Kazuko Machida, Katsuyuki MiyasakaAbstract:As the use of pulse oximeters increases, the needs for higher performance and wider applicability of pulse Oximetry have increased. To realize the full potential of pulse Oximetry, it is indispensable to increase the number of optical wavelengths. To develop a multiwavelength Oximetry system, a physical theory of pulse Oximetry must be constructed. In addition, a theory for quantitative measurement of optical absorption in an optical scatterer, such as in living tissue, remains a difficult theoretical and practical aspect of this problem. We adopted Schuster's theory of radiation through a foggy atmosphere for a basis of theory of pulse Oximetry. We considered three factors affecting pulse Oximetry: the optics, the tissue, and the venous blood. We derived a physical theoretical formula of pulse Oximetry. The theory was confirmed with a full SO2 range experiment. Based on the theory, the three-wavelength method eliminated the effect of tissue and improved the accuracy of Spo2. The five-wavelength method eliminated the effect of venous blood and improved motion artifact elimination. Our theory of multiwavelength pulse Oximetry can be expected to be useful for solving almost all problems in pulse Oximetry such as accuracy, motion artifact, low-pulse amplitude, response delay, and errors using reflection Oximetry which will expand the application of pulse Oximetry. Our theory is probably a rare case of success in solving the difficult problem of quantifying optical density of a substance embedded in an optically scattering medium.
Robert T Brouillette - One of the best experts on this subject based on the ideXlab platform.
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planning adenotonsillectomy in children with obstructive sleep apnea the role of overnight Oximetry
Pediatrics, 2004Co-Authors: Gillian M Nixon, Andrea S Kermack, Michael G Davis, John J Manoukian, Karen Brown, Robert T BrouilletteAbstract:Objective. Obstructive sleep apnea (OSA) in children is usually effectively treated by adenotonsillectomy (TA 22%) had no additional sleep studies before T&A. Timing of T&A was based on Oximetry score, leading to a significant reduction in waiting time for surgery for those with higher Oximetry scores. Postoperative respiratory complications were more common with increasing Oximetry score. Conclusions. Overnight pulse Oximetry can be used to estimate the severity of OSA, to shorten the diagnostic and treatment process for those with more severe disease, and to aid clinicians in prioritization of T&A and planning perioperative care.
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nocturnal pulse Oximetry as an abbreviated testing modality for pediatric obstructive sleep apnea
Pediatrics, 2000Co-Authors: Robert T Brouillette, Angela Morielli, Andra Leimanis, Karen A Waters, Rina Luciano, Francine DucharmeAbstract:Objective. To determine the utility of pulse Oximetry for diagnosis of obstructive sleep apnea (OSA) in children. Methods. We performed a cross-sectional study of 349 patients referred to a pediatric sleep laboratory for possible OSA. A mixed/obstructive apnea/hypopnea index (MOAHI) greater than or equal to 1 on nocturnal polysomnography (PSG) defined OSA. A sleep laboratory physician read nocturnal Oximetry trend and event graphs, blinded to clinical and polysomnographic results. Likelihood ratios were used to determine the change in probability of having OSA before and after Oximetry results were known. Results. Of 349 patients, 210 (60%) had OSA as defined polysomnographically. Oximetry trend graphs were classified as positive for OSA in 93 and negative or inconclusive in 256 patients. Of the 93 Oximetry results read as positive, PSG confirmed OSA in 90 patients. A positive Oximetry trend graph had a likelihood ratio of 19.4, increasing the probability of having OSA from 60% to 97%. The median MOAHI of children with a positive Oximetry result was 16.4 (7.5, 30.2). The 3 false-positive Oximetry results were all in the subgroup of 92 children who had diagnoses other than adenotonsillar hypertrophy that might have affected breathing during sleep. A negative or inconclusive Oximetry result had a likelihood ratio of .58, decreasing the probability of having OSA from 60% to 47%. Interobserver reliability for Oximetry readings was very good to excellent (κ = .80). Conclusions. In the setting of a child suspected of having OSA, a positive nocturnal Oximetry trend graph has at least a 97% positive predictive value. Oximetry could: 1) be the definitive diagnostic test for straightforward OSA attributable to adenotonsillar hypertrophy in children older than 12 months of age, or 2) quickly and inexpensively identify children with a history suggesting sleep-disordered breathing who would require PSG to elucidate the type and severity. A negative Oximetry result cannot be used to rule out OSA.
