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Sensors (Basel, Switzerland) May 2022The purpose of this research was to develop an algorithm for a wearable device that would prevent people from drowning in swimming pools. The device should detect...
The purpose of this research was to develop an algorithm for a wearable device that would prevent people from drowning in swimming pools. The device should detect pre-drowning symptoms and alert the rescue staff. The proposed detection method is based on analyzing real-time data collected from a set of sensors, including a pulse oximeter. The pulse oximetry technique is used for measuring the heart rate and oxygen saturation in the subject's blood. It is an optical method; subsequently, the measurements obtained this way are highly sensitive to interference from the subject's motion. To eliminate noise caused by the subject's movement, accelerometer data were used in the system. If the acceleration sensor does not detect movement, a biosensor is activated, and an analysis of selected physiological parameters is performed. Such a setup of the algorithm allows the device to distinguish situations in which the person rests and does not move from situations in which the examined person has lost consciousness and has begun to drown.
Topics: Drowning; Humans; Oximetry; Oxygen; Swimming Pools; Wearable Electronic Devices
PubMed: 35632232
DOI: 10.3390/s22103823 -
Archivos Argentinos de Pediatria Apr 2022Near infrared spectroscopy (NIRS) is a non-invasive optical technique for the evaluation of regional tissue oxygenation using transcutaneous detectors. In recent years,... (Review)
Review
Near infrared spectroscopy (NIRS) is a non-invasive optical technique for the evaluation of regional tissue oxygenation using transcutaneous detectors. In recent years, publications about this topic have increased exponentially; this reflects the growing interest among investigators and clinicians about this new technology and its potential benefits for pediatric patients. The objective of this review is to know the functioning and potential uses of regional saturation measured by NIRS and establish future challenges.
Topics: Child; Hemodynamic Monitoring; Humans; Oximetry; Oxygen; Pediatrics; Spectroscopy, Near-Infrared
PubMed: 35338818
DOI: 10.5546/aap.2022.eng.129 -
Respiratory Care Dec 2020The aim of CPAP and noninvasive ventilation (NIV) is to correct sleep-disordered breathing and nocturnal gas exchange. The aim of the study was to analyze the results of...
BACKGROUND
The aim of CPAP and noninvasive ventilation (NIV) is to correct sleep-disordered breathing and nocturnal gas exchange. The aim of the study was to analyze the results of a systematic home pulse oximetry ([Formula: see text]) and transcutaneous carbon dioxide ([Formula: see text]) monitoring in stable pediatric subjects on long-term CPAP/NIV or screened for CPAP/NIV weaning, and the consequent interventions in the subjects with abnormal gas exchange.
METHODS
The home overnight [Formula: see text] and [Formula: see text] recordings of stable pediatric subjects treated with or weaned from CPAP, NIV, or high-flow nasal cannula between January 2017 and March 2018 were analyzed.
RESULTS
A total of 110 recordings, performed in 79 subjects, median age 6 (interquartile range [IQR] 1.5-14) y, were analyzed. Fifty-two recordings (47%) were performed during NIV, 43 (39%) during CPAP, 2 (2%) during high-flow nasal cannula, and 13 (12%) during a spontaneous ventilation weaning trial from ventilatory support. The quality of recording was excellent in 81% of recordings, 5 recordings (5%) had <4 h of recording time, 5 (5%) had artifacts on the [Formula: see text] signal, and 16 (15%) had artifacts on the [Formula: see text] signal. Gas exchange abnormalities were observed in 11 subjects with [Formula: see text] > 50 mm Hg during ≥ 2% of recording time ( 8), mean [Formula: see text] ≥ 50 mm Hg ( 6), mean [Formula: see text] < 35 mm Hg ( 3), and [Formula: see text] < 90% during ≥ 2% of recording time ( 2). Consequent interventions were (multiple interventions possible): change of device settings ( 6), change of interface ( 2), switched to high-flow nasal cannula ( 1), and a control recording ( 2).
CONCLUSIONS
A significant number (∼12%) of systematic home [Formula: see text] and [Formula: see text] recordings in stable pediatric subjects treated with CPAP/NIV were abnormal and may be corrected by adequate therapeutic interventions.
Topics: Carbon Dioxide; Child; Humans; Noninvasive Ventilation; Oximetry; Sleep Apnea Syndromes
PubMed: 32723858
DOI: 10.4187/respcare.07488 -
Chronic Respiratory Disease 2022Measurement of oxygen saturation (SO) during the 6 minute walk test (6MWT) could be impacted by the measurement site.
BACKGROUND
Measurement of oxygen saturation (SO) during the 6 minute walk test (6MWT) could be impacted by the measurement site.
AIMS
To compare SO and heart rate (HR) between forehead and finger sensors during the 6MWT. Sensor readings were also to be compared for signal quality and with capillary blood gas (CBG) pre and post 6MWT.
METHOD
80 subjects with pulmonary vascular disease (PVD) and/or interstitial lung disease (ILD) performed the 6MWT. Pulse oximetry was recorded at 30 s intervals. CBG was taken pre and post 6MWT to determine capillary oxygen saturation (SO).
RESULTS
The forehead sensor recorded higher values for SO ( < 0.001) and HR ( < 0.01) compared with the finger sensor during the 6MWT. For both sensors, the demonstrated bias compared to CBG post 6MWT was higher and more variable in subjects who desaturated. During the 6MWT there was a higher occurrence ( < 0.001) of poor signal quality in the finger sensor compared with the forehead sensor.
CONCLUSION
This study suggests that the sensor site can impact pulse oximetry readings. The variance in bias suggests pulse oximetry may not accurately reflect SO measurements particularly in subjects who desaturate during 6MWT.
Topics: Humans; Forehead; Lung Diseases, Interstitial; Oximetry; Oxygen; Walk Test
PubMed: 35045761
DOI: 10.1177/14799731211070844 -
Journal of Perinatology : Official... Jan 2022Pulse oximetry is commonly used in Neonatology, however recent adult data suggest racial disparity in accuracy, with overestimation of oxygen saturation for Black...
OBJECTIVE
Pulse oximetry is commonly used in Neonatology, however recent adult data suggest racial disparity in accuracy, with overestimation of oxygen saturation for Black patients.
STUDY DESIGN
Black and White infants <32 weeks gestation underwent simultaneous arterial blood gas and pulse oximetry measurement. Error by race was examined using mean bias, A, Bland-Altman, and linear/non-linear analysis.
RESULTS
A total of 294 infants (124 Black, 170 White) were identified with mean GA of 25.8 ± 2.1 weeks and mean BW of 845 ± 265 grams, yielding 4387 SaO-SpO datapoints. SpO overestimation, measured by mean bias, was 2.4-fold greater for Black infants and resulted in greater occult hypoxemia (SpO > 90% when SaO < 85%; 9.2% vs. 7.7% of samples). Sensitivity and specificity for detection of true hypoxemia were similar between groups (39 vs. 38%; 81 vs. 78%).
CONCLUSION
There is a modest but consistent difference in SpO error between Black and White infants, with increased incidence of occult hypoxemia in Black infants.
Topics: Adult; Blood Gas Analysis; Humans; Hypoxia; Infant, Newborn; Infant, Premature; Oximetry; Oxygen
PubMed: 34642469
DOI: 10.1038/s41372-021-01230-3 -
Anesthesiology Sep 2022
Topics: Ethnicity; Healthcare Disparities; Humans; Hypoxia; Oximetry; Self Report
PubMed: 35767661
DOI: 10.1097/ALN.0000000000004291 -
Magnetic Resonance in Medicine Aug 2021Cerebral T oximetry is a non-invasive imaging method to measure blood T and cerebral venous oxygenation. Measured T values are converted to oximetry estimates using...
PURPOSE
Cerebral T oximetry is a non-invasive imaging method to measure blood T and cerebral venous oxygenation. Measured T values are converted to oximetry estimates using carefully validated and potentially disease-specific calibrations. In sickle cell disease, red blood cells have abnormal cell shape and membrane properties that alter T oximetry calibration relationships in clinically meaningful ways. Previous in vitro works by two independent groups established potentially competing calibration models.
METHODS
This study analyzed pooled datasets from these two studies to establish a unified and more robust sickle-specific calibration to serve as a reference standard in the field.
RESULTS
Even though the combined calibration did not demonstrate statistical superiority compared to previous models, the calibration was unbiased compared to blood-gas co-oximetry and yielded limits of agreement of (-10.1%, 11.6%) in non-transfused subjects with sickle cell disease. In transfused patients, this study proposed a simple correction method based on individual hemoglobin S percentage that demonstrated reduced bias in saturation measurement compared to previous uncorrected sickle calibrations.
CONCLUSION
The combined calibration is based on a larger range of hematocrit, providing greater confidence in the hematocrit-dependent model parameters, and yielded unbiased estimates to blood-gas co-oximetry measurements from both sites. Additionally, this work also demonstrated the need to correct for transfusion in T oximetry measurements for hyper-transfused sickle cell disease patients and proposes a correction method based on patient-specific hemoglobin S concentration.
Topics: Anemia, Sickle Cell; Calibration; Humans; Magnetic Resonance Imaging; Oximetry; Oxygen
PubMed: 33719133
DOI: 10.1002/mrm.28757 -
Sensors (Basel, Switzerland) Nov 2023Obstructive Sleep Apnea (OSA) is a respiratory disorder characterized by frequent breathing pauses during sleep. The apnea-hypopnea index is a measure used to assess the... (Review)
Review
Obstructive Sleep Apnea (OSA) is a respiratory disorder characterized by frequent breathing pauses during sleep. The apnea-hypopnea index is a measure used to assess the severity of sleep apnea and the hourly rate of respiratory events. Despite numerous commercial devices available for apnea diagnosis and early detection, accessibility remains challenging for the general population, leading to lengthy wait times in sleep clinics. Consequently, research on monitoring and predicting OSA has surged. This comprehensive paper reviews devices, emphasizing distinctions among representative apnea devices and technologies for home detection of OSA. The collected articles are analyzed to present a clear discussion. Each article is evaluated according to diagnostic elements, the implemented automation level, and the derived level of evidence and quality rating. The findings indicate that the critical variables for monitoring sleep behavior include oxygen saturation (oximetry), body position, respiratory effort, and respiratory flow. Also, the prevalent trend is the development of level IV devices, measuring one or two signals and supported by prediction software. Noteworthy methods showcasing optimal results involve neural networks, deep learning, and regression modeling, achieving an accuracy of approximately 99%.
Topics: Humans; Polysomnography; Sleep Apnea, Obstructive; Sleep; Sleep Apnea Syndromes; Oximetry
PubMed: 38067885
DOI: 10.3390/s23239512 -
Acta Ophthalmologica Nov 2022The aim of the study was to obtain the values of oxygen saturation in retinal vessels and ophthalmic blood flow parameters in a healthy Caucasian population and assess...
PURPOSE
The aim of the study was to obtain the values of oxygen saturation in retinal vessels and ophthalmic blood flow parameters in a healthy Caucasian population and assess whether the oximetry parameters are affected by the flow rate or the vascular resistance.
METHODS
The spectrophotometric retinal oximetry and colour Doppler imaging (CDI) of retinal vessels were successfully performed with 52 healthy subjects (average age 29.7 ± 5.6 years). The retinal oximeter simultaneously measures the wavelength difference of haemoglobin oxygen saturation in retinal arterioles and venules. The arteriolar and venular saturation in both eyes was measured. The peak systolic (PSV) end diastolic (EDV) velocities, resistive (RI) and pulsatility (PI) indices were obtained for both eyes using CDI in the ophthalmic artery. A paired t-test and two sample t-tests were used for statistical analyses. The correlation was assessed using the Pearson coefficient correlation.
RESULTS
The mean oxygen saturation level was 96.9 ± 3.0% for the retinal arterioles and 65.0 ± 5.1% for the retinal venules. The A-V difference was 31.8 ± 4.6%. The mean of the measured haemodynamic parameters was PSV 46.6 ± 9.4 cm/s, EDV 12.0 ± 3.5 cm/s, PI 1.68 ± 0.38 and RI 0.74 ± 0.05. No significant difference in oxygen saturation and haemodynamic parameters was found between the left and the right eyes or the dominant and non-dominant eye. The oximetry and ultrasound values were sex independent. The Pearson correlation coefficient demonstrated a significant yet weak negative correlation between A-V difference and RI (r = -0.321, p = 0.020).
CONCLUSIONS
A negative correlation between A-V difference and resistance index was observed, suggesting that reduced oxygen consumption may reflect the increased vascular tone of the ophthalmic vessels, which is likely determined by autoregulatory mechanisms.
Topics: Adult; Blood Flow Velocity; Healthy Volunteers; Hemodynamics; Hemoglobins; Humans; Ophthalmic Artery; Oximetry; Oxygen; Oxygen Saturation; Retina; Retinal Artery; Young Adult
PubMed: 35599335
DOI: 10.1111/aos.15189 -
Resuscitation Dec 2021
Topics: Cardiopulmonary Resuscitation; Humans; Oximetry; Plethysmography
PubMed: 34757060
DOI: 10.1016/j.resuscitation.2021.10.039