scholarly journals Pulse Oximetry with Two Infrared Wavelengths without Calibration in Extracted Arterial Blood

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3457 ◽  
Author(s):  
Ohad Yossef Hay ◽  
Meir Cohen ◽  
Itamar Nitzan ◽  
Yair Kasirer ◽  
Sarit Shahroor-karni ◽  
...  
Keyword(s):  
Pulse Oximetry ◽  
Pulse Oximeter ◽  
Breath Holding ◽  
Arterial Line ◽  
Non Invasive ◽  
Arterial Blood ◽  
Infrared Wavelengths ◽  
Path Lengths ◽  
Similar Accuracy ◽  
Pulse Oximeters

Oxygen saturation in arterial blood (SaO2) provides information about the performance of the respiratory system. Non-invasive measurement of SaO2 by commercial pulse oximeters (SpO2) make use of photoplethysmographic pulses in the red and infrared regions and utilizes the different spectra of light absorption by oxygenated and de-oxygenated hemoglobin. Because light scattering and optical path-lengths differ between the two wavelengths, commercial pulse oximeters require empirical calibration which is based on SaO2 measurement in extracted arterial blood. They are still prone to error, because the path-lengths difference between the two wavelengths varies among different subjects. We have developed modified pulse oximetry, which makes use of two nearby infrared wavelengths that have relatively similar scattering constants and path-lengths and does not require an invasive calibration step. In measurements performed on adults during breath holding, the two-infrared pulse oximeter and a commercial pulse oximeter showed similar changes in SpO2. The two pulse oximeters showed similar accuracy when compared to SaO2 measurement in extracted arterial blood (the gold standard) performed in intensive care units on newborns and children with an arterial line. Errors in SpO2 because of variability in path-lengths difference between the two wavelengths are expected to be smaller in the two-infrared pulse oximeter.

Pulse Oximetry: An Alternative Method for the Assessment of Oxygenation in Newborn Infants

PEDIATRICS ◽  
1987 ◽  
Vol 79 (4) ◽  
pp. 524-528
Author(s):  
Michael S. Jennis ◽  
Joyce L. Peabody
Keyword(s):  
Pulse Oximetry ◽  
Pulse Oximeter ◽  
Arterial Oxygen Saturation ◽  
Newborn Infants ◽  
Fetal Hemoglobin ◽  
Arterial Oxygen ◽  
Skin Injury ◽  
Reliable Technique ◽  
Arterial Blood

Continuous monitoring of oxygenation in sick newborns is vitally important. However, transcutaneous Po2 measurements have a number of limiations. Therefore, we report the use of the pulse oximeter for arterial oxygen saturation (Sao2) determination in 26 infants (birth weights 725 to 4,000 g, gestational ages 24 to 40 weeks, and postnatal ages one to 49 days). Fetal hemoglobin determinations were made on all infants and were repeated following transfusion. Sao2, readings from the pulse oximeter were compared with the Sao2 measured in vitro on simultaneously obtained arterial blood samples. The linear regression equation for 177 paired measurements was: y = 0.7x + 27.2; r = .9. However, the differences between measured Sao2 and the pulse oximeter Sao2 were significantly greater in samples with > 50% fetal hemoglobin when compared with samples with < 25% fetal hemoglobin (P < .001). The pulse oximeter was easy to use, recorded trends in oxygenation instantaneously, and was not associated with skin injury. We conclude that pulse oximetry is a reliable technique for the continuous, noninvasive monitoring of oxygenation in newborn infants.

Understanding the use of pulse oximetry in COVID-19 disease

2021 ◽  
Vol 32 (8) ◽  
pp. 312-316
Author(s):  
Paul Silverston
Keyword(s):  
Oxygen Saturation ◽  
Pulse Oximetry ◽  
Respiratory Symptoms ◽  
Disease Process ◽  
Clinical Findings ◽  
The Other ◽  
Know How ◽  
Non Invasive ◽  
Pulse Oximeters ◽  
The Way

The pandemic has led to an increase in the use of pulse oximetry to assess and manage patients with COVID-19 disease. Paul Silverston explains the principles of pulse oximetry and the factors that can affect the reliability and accuracy of readings Pulse oximetry is performed to detect and quantify the degree of hypoxia in patients with respiratory symptoms and illnesses, including patients with COVID-19 disease. Pulse oximeters are non-invasive, simple to use and inexpensive, but it is important to know how to interpret the readings in the context of the patient's symptoms and the other clinical findings. In COVID-19 disease, very small differences in the oxygen saturation reading result in significant differences in the way that the patient is managed, so it is important to be aware of the factors that can affect these readings. It is also important to appreciate that a low reading in a patient with suspected or confirmed COVID-19 disease may be the result of another disease process.

Measurement of Carboxyhemoglobin and Methemoglobin by Pulse Oximetry

2006 ◽  
Vol 105 (5) ◽  
pp. 892-897 ◽  
Author(s):  
Steven J. Barker ◽  
Jeremy Curry ◽  
Daniel Redford ◽  
Scott Morgan
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Saturation ◽  
Pulse Oximetry ◽  
Sodium Nitrite ◽  
Pulse Oximeter ◽  
Hemoglobin Oxygen Saturation ◽  
Arterial Blood ◽  
Human Volunteers ◽  
Oxygenation Monitoring ◽  
Intravenous Sodium

Background A new eight-wavelength pulse oximeter is designed to measure methemoglobin and carboxyhemoglobin, in addition to the usual measurements of hemoglobin oxygen saturation and pulse rate. This study examines this device's ability to measure dyshemoglobins in human volunteers in whom controlled levels of methemoglobin and carboxyhemoglobin are induced. Methods Ten volunteers breathed 500 ppm carbon monoxide until their carboxyhemoglobin levels reached 15%, and 10 different volunteers received intravenous sodium nitrite, 300 mg, to induce methemoglobin. All were instrumented with arterial cannulas and six Masimo Rad-57 (Masimo Inc., Irvine, CA) pulse oximeter sensors. Arterial blood was analyzed by three laboratory CO-oximeters, and the resulting carboxyhemoglobin and methemoglobin measurements were compared with the corresponding pulse oximeter readings. Results The Rad-57 measured carboxyhemoglobin with an uncertainty of +/-2% within the range of 0-15%, and it measured methemoglobin with an uncertainty of 0.5% within the range of 0-12%. Conclusion The Masimo Rad-57 is the first commercially available pulse oximeter that can measure methemoglobin and carboxyhemoglobin, and it therefore represents an expansion of our oxygenation monitoring capability.

Validity of pulse oximetry during exercise in elite endurance athletes

1992 ◽  
Vol 72 (2) ◽  
pp. 455-458 ◽  
Author(s):  
D. Martin ◽  
S. Powers ◽  
M. Cicale ◽  
N. Collop ◽  
D. Huang ◽  
...  
Keyword(s):  
Pulse Oximeter ◽  
High Intensity ◽  
Aerobic Power ◽  
Constant Load ◽  
Cycle Exercise ◽  
Exercise Tests ◽  
Arterial Blood ◽  
Highly Correlated ◽  
Pulse Oximeters ◽  
Finger Probe

Eleven highly trained male cyclists [maximal aerobic power (VO2max) = 70.6 +/- 4.2 ml.kg-1.min-1] performed both high intensity constant load (90–95% VO2max) and incremental cycle exercise tests with arterial blood sampling to evaluate the accuracy of pulse oximeter estimates (%SpO2) of arterial oxyhemoglobin fraction of total hemoglobin (%HbO2). Three subjects also performed an incremental exercise test in hypoxic conditions (inspired partial pressure of O2 = 89, 93, or 100 Torr). Arterial %HbO2 was determined via CO-oximetry and ranged from 72 to 99%. Three Ohmeda 3740 pulse oximeters were used to estimate %HbO2, one on each ear lobe and a finger probe. The finger probe tended to provide the best estimate of %HbO2 during exercise: the mean %SpO2 - %HbO2 difference for 232 exercise observations was 0.52 +/- 1.36% (SD). Finger probe %SpO2 and %HbO2 were highly correlated [r = 0.98, standard error of the estimate (SEE) = 1.32%, P less than 0.0001]. The accuracy of pulse oximeters has been questioned during high-intensity exercise. When aerobic power was greater than 81% of VO2max (n = 75), the finger probe's mean error was -0.01 +/- 1.40%. Finger probe %SpO2 and %HbO2 were highly correlated (r = 0.97, SEE = 1.32%, P less than 0.0001). These results indicate that this pulse oximeter is a valid predictor of %HbO2 in elite athletes during cycle exercise.

scholarly journals Bedside Pulse Oximeters with a Clinical Algorithm Make Economic Sense in the Intensive Care Unit

1996 ◽  
Vol 3 (1) ◽  
pp. 47-51
Author(s):  
David J Leasa ◽  
Jacqueline M Walker
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Pulse Oximeter ◽  
Cost Savings ◽  
Clinical Algorithm ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Before And After ◽  
The Mean ◽  
Pulse Oximeters

OBJECTIVE:To determine the effect on arterial blood gas (ABG) and hospital resource use by introducing a strategy of using bedside oximeters with a clinical algorithm, based on the argument that bedside pulse oximeters make economic sense in the intensive care unit (ICU) if safe patient oxygenation can be ensured at a lower cost than that of existing monitoring options.DESIGN:A before and after design was used to examine the consequences of a pulse oximeter at each bedside in the ICU along with a pulse oximeter clinical algorithm (POCA) describing use for titrating oxygen therapy and for performing ABG analysis.SETTING:A 19-bed multidisciplinary ICU with a six-bed extended ICU (EICU) available to function as a 'step-down' facility.PATIENTS:All patients admitted to the ICU/EICU over two 12-month periods were included.RESULTS:The strategy yielded a 31% reduction in the mean number of ABGs per patient after POCA (20.0±26.1 versus 13.8±16.7, mean ± SD; P<0.001) as well as a potential annual cost savings of $32,831.CONCLUSIONS:Bedside oximeters within the ICU, when used with explicit guidelines, reduce ABG use and result in hospital cost savings.

scholarly journals First Evaluation of a Newly Constructed Underwater Pulse Oximeter for Use in Breath-Holding Activities

2021 ◽  
Vol 12 ◽  
Author(s):  
Eric Mulder ◽  
Erika Schagatay ◽  
Arne Sieber
Keyword(s):  
Oxygen Saturation ◽  
Pulse Oximeter ◽  
Arterial Oxygen Saturation ◽  
Dropout Rate ◽  
Arterial Oxygen ◽  
Breath Holding ◽  
Signal Loss ◽  
Physiological Variables ◽  
Dry Conditions ◽  
Pulse Oximeters

Studying risk factors in freediving, such as hypoxic blackout, requires development of new methods to enable remote underwater monitoring of physiological variables. We aimed to construct and evaluate a new water- and pressure proof pulse oximeter for use in freediving research. The study consisted of three parts: (I) A submersible pulse oximeter (SUB) was developed on a ruggedized platform for recording of physiological parameters in challenging environments. Two MAX30102 sensors were used to record plethysmograms, and included red and infra-red emitters, diode drivers, photodiode, photodiode amplifier, analog to digital converter, and controller. (II) We equipped 20 volunteers with two transmission pulse oximeters (TPULS) and SUB to the fingers. Arterial oxygen saturation (SpO2) and heart rate (HR) were recorded, while breathing room air (21% O2) and subsequently a hypoxic gas (10.7% O2) at rest in dry conditions. Bland-Altman analysis was used to evaluate bias and precision of SUB relative to SpO2 values from TPULS. (III) Six freedivers were monitored with one TPULS and SUB placed at the forehead, during a maximal effort immersed static apnea. For dry baseline measurements (n = 20), SpO2 bias ranged between −0.8 and −0.6%, precision between 1.0 and 1.5%; HR bias ranged between 1.1 and 1.0 bpm, precision between 1.4 and 1.9 bpm. For the hypoxic episode, SpO2 bias ranged between −2.5 and −3.6%, precision between 3.6 and 3.7%; HR bias ranged between 1.4 and 1.9 bpm, precision between 2.0 and 2.1 bpm. Freedivers (n = 6) performed an apnea of 184 ± 53 s. Desaturation- and resaturation response time of SpO2 was approximately 15 and 12 s shorter in SUB compared to TPULS, respectively. Lowest SpO2 values were 76 ± 10% for TPULS and 74 ± 13% for SUB. HR traces for both pulse oximeters showed similar patterns. For static apneas, dropout rate was larger for SUB (18%) than for TPULS (&lt;1%). SUB produced similar SpO2 and HR values as TPULS, both during normoxic and hypoxic breathing (n = 20), and submersed static apneas (n = 6). SUB responds more quickly to changes in oxygen saturation when sensors were placed at the forehead. Further development of SUB is needed to limit signal loss, and its function should be tested at greater depth and lower saturation.

Pulse Oximetry: Theory and Applications for Noninvasive Monitoring

1992 ◽  
Vol 38 (9) ◽  
pp. 1601-1607 ◽  
Author(s):  
Y Mendelson
Keyword(s):  
Pulse Oximetry ◽  
Near Infrared ◽  
Arterial Oxygen Saturation ◽  
Theoretical Background ◽  
Blood Oxygenation ◽  
Advanced Technology ◽  
Arterial Oxygen ◽  
Arterial Blood ◽  
Technological Advances ◽  
Pulse Oximeters

Abstract Noninvasive measurement of arterial oxygen saturation (SaO2) by pulse oximetry is widely acknowledged to be one of the most important technological advances in monitoring clinical patients. Pulse oximeters compute SaO2 by measuring differences in the visible and near infrared absorbances of fully oxygenated and deoxygenated arterial blood. Unlike clinical blood gas analyzers, which require a sample of blood from the patient and can provide only intermittent measurement of patient oxygenation, pulse oximeters provide continuous, safe, and instantaneous measurement of blood oxygenation. Here I review the theoretical background behind this advanced technology, instrumentation requirements, practical instrument calibration, common features of commercial pulse oximeters, specific clinical applications, and performance limitations of pulse oximeters.

Pulse Oximetry

2011 ◽  
Author(s):  
Patrick Magee ◽  
Mark Tooley
Keyword(s):  
Oxygen Saturation ◽  
Pulse Oximeter ◽  
Anaesthetic Machine ◽  
Additional Information ◽  
Non Invasive ◽  
Point Of Interest ◽  
Arterial Blood ◽  
Body Tissues ◽  
Oxygen Analyser

The pulse oximeter is a device for non-invasive, continuous measurement of oxygen saturation. As such it is arguably one of the most important intraoperative monitors at the disposal of anaesthetists, and efforts are being made to make pulse oximeters available at all operating locations throughout the world [Walker et al. 2009]. Although the device measures oxygen saturation of arterial blood, which is the physiological end point of interest, it is not a replacement for monitoring all the events which may lead to hypoxaemia; in other words it does not replace an oxygen analyser at the common gas outlet of the anaesthetic machine. Depending on the site of the probe, usually ear lobe or finger, there is a variable delay between the onset of a causative hypoxaemic event and detection of hypoxaemia by the pulse oximeter, the delay being longer the more peripherally placed is the probe. Appropriate size and design of the probe for accuracy and safety in children is important [Howell et al. 1993] and finger probes are more accurate but slower to respond than ear probes [Webb et al. 1991]. Forehead reflectance probes have been used with good results [Casati et al. 2007]. It is also true that the human eye is notoriously bad at detecting cyanosis in the range of saturations 81–85%. For additional information on Monitoring Principles see Chapter 11. It is clear, however, that in a hierarchy of monitors for anaesthesia, the pulse oximeter is indispensable. A pulse oximeter uses two separate technologies: one is plethysmography, where reproduction of the pulsatile waveform takes place; the other is spectroscopy, where absorption of light of specific wavelengths by body tissues occurs and is analysed. The spectroscopic aspects depend on the laws of Beer and Lambert, which can be combined to state that the amount of light absorbed by a substance is proportional to the thickness of the substance sample (the path length of the light) and the concentration of the substance.

Research: Comparison of the Accuracy of a Pocket versus Standard Pulse Oximeter

2016 ◽  
Vol 50 (3) ◽  
pp. 190-193 ◽  
Author(s):  
João Cordeiro da Costa ◽  
Paula Faustino ◽  
Ricardo Lima ◽  
Inês Ladeira ◽  
Miguel Guimarães
Keyword(s):  
Pulse Oximetry ◽  
Pulse Oximeter ◽  
Blood Gas Analysis ◽  
Quality Standard ◽  
Gas Analysis ◽  
Current Evidence ◽  
Self Monitoring ◽  
Precision Error ◽  
Arterial Blood ◽  
Standard Pulse

Abstract Background: Pulse oximetry has become an essential tool in clinical practice. With patient self-management becoming more prevalent, pulse oximetry self-monitoring has the potential to become common practice in the near future. This study sought to compare the accuracy of two pulse oximeters, a high-quality standard pulse oximeter and an inexpensive pocket pulse oximeter, and to compare both devices with arterial blood co-oximetry oxygen saturation. Methods: A total of 95 patients (35.8% women; mean [±SD] age 63.1 ± 13.9 years; mean arterial pressure was 92 ± 12.0 mmHg; mean axillar temperature 36.3 ± 0.4°C) presenting to our hospital for blood gas analysis was evaluated. The Bland-Altman technique was performed to calculate bias and precision, as well as agreement limits. Student's t test was performed. Results: Standard oximeter presented 1.84% bias and a precision error of 1.80%. Pocket oximeter presented a bias of 1.85% and a precision error of 2.21%. Agreement limits were −1.69% to 5.37% (standard oximeter) and −2.48% to 6.18% (pocket oximeter). Conclusion: Both oximeters presented bias, which was expected given previous research. The pocket oximeter was less precise but had agreement limits that were comparable with current evidence. Pocket oximeters can be powerful allies in clinical monitoring of patients based on a self-monitoring/efficacy strategy.

scholarly journals Pulse Rate and Oxygen Level Measurement Using Arduino

2021 ◽  
Vol 9 (VII) ◽  
pp. 1518-1524
Author(s):  
Shiv Prakash Singh
Keyword(s):  
Heart Rate ◽  
Oxygen Saturation ◽  
The Body ◽  
Intensity Change ◽  
Blood Oxygen Saturation ◽  
Non Invasive ◽  
Level Measurement ◽  
Arterial Blood ◽  
Use Of Technology ◽  
Infrared Wavelengths

Use of technology in healthcare is growing importance as a result of the tendency to acquire chronic disease like heart attack and high blood pressure. Heart rate and blood oxygen saturation is a couple of such biometrics that is monitored in this project to provide information regarding the health of the body. By measuring the intensity change of light transmitted through tissue due to arterial blood, heart rate is measured. Furthermore, oxygenated blood has different light absorption characteristics than deoxygenated blood under red and infrared wavelengths. Comparing the absorptions produce an estimate of the oxygen saturation of blood. The purpose is to examine how heart rate and the oxygen saturation of subject is measured from finger and then processed and displayed. The design, is small in size, easy to use, allows a non- invasive, real time method to provide information regarding health. This enables an efficient and economical means for managing the health care. This document is intended to be used by engineers, medical equipment developers, anyone related to medical practice and interested in understanding the operation of pulse oximeter and heart rate monitoring system.

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