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

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 (<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.

2005 ◽  
Vol 102 (4) ◽  
pp. 715-719 ◽  
Author(s):  
Philip E. Bickler ◽  
John R. Feiner ◽  
John W. Severinghaus

Background It is uncertain whether skin pigmentation affects pulse oximeter accuracy at low HbO2 saturation. Methods The accuracy of finger pulse oximeters during stable, plateau levels of arterial oxygen saturation (Sao2) between 60 and 100% were evaluated in 11 subjects with darkly pigmented skin and in 10 with light skin pigmentation. Oximeters tested were the Nellcor N-595 with the OxiMax-A probe (Nellcor Inc., Pleasanton, CA), the Novametrix 513 (Novametrix Inc., Wallingford, CT), and the Nonin Onyx (Nonin Inc., Plymouth, MN). Semisupine subjects breathed air-nitrogen-carbon dioxide mixtures through a mouthpiece. A computer used end-tidal oxygen and carbon dioxide concentrations determined by mass spectrometry to estimate breath-by-breath Sao2, from which an operator adjusted inspired gas to rapidly achieve 2- to 3-min stable plateaus of desaturation. Comparisons of oxygen saturation measured by pulse oximetry (Spo2) with Sao2 (by Radiometer OSM3) were used in a multivariate model to determine the interrelation between saturation, skin pigmentation, and oximeter bias (Spo2 - Sao2). Results At 60-70% Sao2, Spo2 (mean of three oximeters) overestimated Sao2 (bias +/- SD) by 3.56 +/- 2.45% (n = 29) in darkly pigmented subjects, compared with 0.37 +/- 3.20% (n = 58) in lightly pigmented subjects (P < 0.0001). The SD of bias was not greater with dark than light skin. The dark-light skin differences at 60-70% Sao2 were 2.35% (Nonin), 3.38% (Novametrix), and 4.30% (Nellcor). Skin pigment-related differences were significant with Nonin below 70% Sao2, with Novametrix below 90%, and with Nellcor at all ranges. Pigment-related bias increased approximately in proportion to desaturation. Conclusions The three tested pulse oximeters overestimated arterial oxygen saturation during hypoxia in dark-skinned individuals.


2015 ◽  
Vol 27 (01) ◽  
pp. 1550007 ◽  
Author(s):  
Chun-Hao Lu ◽  
Jiun-Hung Lin ◽  
Han-Ming Huang ◽  
Cheng-Yang Huang ◽  
Cheng-Chi Tai

A pulse oximeter is a noninvasive instrument used in clinical medicine to monitor arterial oxygen saturation. Fingertip-type pulse oximeters are popular, but their inconvenience for long-term monitoring in daily life means that other types of wearable pulse oximeters, such as a ring-type reflection pulse oximeter, needs to be developed. However, designing a ring-type pulse oximeter for measuring the oxygen saturation is difficult due to the complex tissue architecture of the finger base. This study used human tissue simulations to evaluate the practicability of a ring-type reflection pulse oximeter design. Moreover, given that the collection of diffusely reflected light can be enhanced by using a parabolic reflector, the efficacy of a ring-type reflection pulse oximeter with a parabolic reflector was also evaluated.


1997 ◽  
Vol 86 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Steven J. Barker ◽  
Nitin K. Shah

Background Pulse oximetry is considered a standard of care in both the operating room and the postanesthetic care unit, and it is widely used in all critical care settings. Pulse oximeters may fail to provide valid SpO2 data in various situations that produce low signal-to-noise ratio. Motion artifact is a common cause of oximeter failure and loss of accuracy. This study compares the accuracy and data dropout rates of three current pulse oximeters during standardized motion in healthy volunteers. Methods Ten healthy volunteers were monitored by three different pulse oximeters: Nellcor N-200, Nellcor N-3000, and Masimo SET (prototype). Sensors were placed on digits 2, 3, and 4 of the test hand, which was strapped to a mechanical motion table. The opposite hand was used as a stationary control and was monitored with the same pulse oximeters and an arterial cannula. Arterial oxygen saturation was varied from 100% to 75% by changing the inspired oxygen concentration. While SpO2 was both constant and changing, the oximeter sensors were connected before and during motion. Oximeter errors and dropout rates were digitally recorded continuously during each experiment. Results If the oximeter was functioning before motion began, the following are the percentages of time when the instrument displayed an SpO2 value within 7% of control: N-200 = 76%, N-3000 = 87%, and Masimo = 99%. When the oximeter sensor was connected after the beginning of motion, the values were N-200 = 68%, N-3000 = 47%, and Masimo = 97%. If the alarm threshold was chosen SpO2 less than 90%, then the positive predictive values (true alarms/total alarms) are N-200 = 73%, N-3000 = 81%, and Masimo = 100%. In general, N-200 had the greatest SpO2 errors and N-3000 had the highest dropout rates. Conclusions The mechanical motions used in this study significantly affected oximeter function, particularly when the sensors were connected during motion, which requires signal acquisition during motion. The error and dropout rate performance of the Masimo was superior to that of the other two instruments during all test conditions. Masimo uses a new paradigm for oximeter signal processing, which appears to represent a significant advance in low signal-to-noise performance.


Author(s):  
Aslıhan Gürün Kaya ◽  
Miraç Öz ◽  
İREM AKDEMİR KALKAN ◽  
Ezgi Gülten ◽  
güle AYDIN ◽  
...  

Introduction: Guidelines recommend using a pulse oximeter rather than arterial blood gas (ABG) for COVID-19 patients. However, significant differences can be observed between oxygen saturation measured by pulse oximetry (SpO2) and arterial oxygen saturation (SaO2) in some clinical conditions. We aimed to assess the reliability of pulse oximeter in patients with COVID-19 Methods: We retrospectively reviewed ABG analyses and SpO2 levels measured simultaneously with ABG in patients hospitalized in COVID-19 wards. Results: We categorized total 117 patients into two groups; in whom the difference between SpO2 and SaO2 was 4% (acceptable difference) and >4% (large difference). Large difference group exhibited higher neutrophil count, C-reactive protein, ferritin, fibrinogen, D-dimer and lower lymphocyte count. Multivariate analyses revealed that increased fibrinogen, increased ferritin and decreased lymphocyte count were independent risk factors for large difference between SpO2 and SaO2. The total study group demonstrated the negative bias of 4.02% with the limits of agreement of −9.22% to 1.17%. The bias became significantly higher in patients with higher ferritin, fibrinogen levels and lower lymphocyte count. Conclusion: Pulse oximeters may not be sufficient to assess actual oxygen saturation especially in COVID-19 patients with high ferritin and fibrinogen levels and low lymphocyte count low SpO2 measurements.


2018 ◽  
Vol 128 (3) ◽  
pp. 520-530 ◽  
Author(s):  
Aaron Louie ◽  
John R. Feiner ◽  
Philip E. Bickler ◽  
Laura Rhodes ◽  
Michael Bernstein ◽  
...  

Abstract Background Pulse oximeter performance is degraded by motion artifacts and low perfusion. Manufacturers developed algorithms to improve instrument performance during these challenges. There have been no independent comparisons of these devices. Methods We evaluated the performance of four pulse oximeters (Masimo Radical-7, USA; Nihon Kohden OxyPal Neo, Japan; Nellcor N-600, USA; and Philips Intellivue MP5, USA) in 10 healthy adult volunteers. Three motions were evaluated: tapping, pseudorandom, and volunteer-generated rubbing, adjusted to produce photoplethsmogram disturbance similar to arterial pulsation amplitude. During motion, inspired gases were adjusted to achieve stable target plateaus of arterial oxygen saturation (SaO2) at 75%, 88%, and 100%. Pulse oximeter readings were compared with simultaneous arterial blood samples to calculate bias (oxygen saturation measured by pulse oximetry [SpO2] − SaO2), mean, SD, 95% limits of agreement, and root mean square error. Receiver operating characteristic curves were determined to detect mild (SaO2 < 90%) and severe (SaO2 < 80%) hypoxemia. Results Pulse oximeter readings corresponding to 190 blood samples were analyzed. All oximeters detected hypoxia but motion and low perfusion degraded performance. Three of four oximeters (Masimo, Nellcor, and Philips) had root mean square error greater than 3% for SaO2 70 to 100% during any motion, compared to a root mean square error of 1.8% for the stationary control. A low perfusion index increased error. Conclusions All oximeters detected hypoxemia during motion and low-perfusion conditions, but motion impaired performance at all ranges, with less accuracy at lower SaO2. Lower perfusion degraded performance in all but the Nihon Kohden instrument. We conclude that different types of pulse oximeters can be similarly effective in preserving sensitivity to clinically relevant hypoxia.


2010 ◽  
Vol 13 (2) ◽  
pp. 278-285 ◽  
Author(s):  
J. P. Phillips ◽  
R. M. Langford ◽  
S. H. Chang ◽  
K. Maney ◽  
P. A. Kyriacou ◽  
...  

2020 ◽  
Vol 15 (3) ◽  
pp. 371-377
Author(s):  
Byung-Moon Choi ◽  
Bong Jin Kang ◽  
Ho-Yong Yun ◽  
Bokyoung Jeon ◽  
Ji-Yeon Bang ◽  
...  

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.


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