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Pulmonology 2022
Topics: Humans; Noninvasive Ventilation; Oximetry
PubMed: 35339420
DOI: 10.1016/j.pulmoe.2022.02.008 -
Proceedings of the National Academy of... May 2020Assessing oxygen saturation (sO) remains challenging but is nonetheless necessary for understanding retinal metabolism. We and others previously achieved oximetry on...
Assessing oxygen saturation (sO) remains challenging but is nonetheless necessary for understanding retinal metabolism. We and others previously achieved oximetry on major retinal vessels and measured the total retinal oxygen metabolic rate in rats using visible-light optical coherence tomography. Here we extend oximetry measurements to capillaries and investigate all three retinal vascular plexuses by amplifying and extracting the spectroscopic signal from each capillary segment under the guidance of optical coherence tomography (OCT) angiography. Using this approach, we measured capillary sO in the retinal circulation in rats, demonstrated reproducibility of the results, validated the measurements in superficial capillaries with known perfusion pathways, and determined sO responses to hypoxia and hyperoxia in the different retinal capillary beds. OCT capillary oximetry has the potential to provide new insights into the retinal circulation in the normal eye as well as in retinal vascular diseases.
Topics: Algorithms; Animals; Capillaries; Hypoxia; Image Processing, Computer-Assisted; Oximetry; Oxygen; Rats; Retinal Vessels; Signal Processing, Computer-Assisted; Tomography, Optical Coherence
PubMed: 32398376
DOI: 10.1073/pnas.1918546117 -
Respirology (Carlton, Vic.) Dec 2023
Topics: Humans; Oximetry; Sleep Apnea, Obstructive
PubMed: 37882673
DOI: 10.1111/resp.14615 -
Advanced Science (Weinheim,... May 2021For wearable electronics/optoelectronics, thermal management should be provided for accurate signal acquisition as well as thermal comfort. However, outdoor solar energy...
For wearable electronics/optoelectronics, thermal management should be provided for accurate signal acquisition as well as thermal comfort. However, outdoor solar energy gain has restricted the efficiency of some wearable devices like oximeters. Herein, wireless/battery-free and thermally regulated patch-type tissue oximeter (PTO) with radiative cooling structures are presented, which can measure tissue oxygenation under sunlight in reliable manner and will benefit athlete training. To maximize the radiative cooling performance, a nano/microvoids polymer (NMVP) is introduced by combining two perforated polymers to both reduce sunlight absorption and maximize thermal radiation. The optimized NMVP exhibits sub-ambient cooling of 6 °C in daytime under various conditions such as scattered/overcast clouds, high humidity, and clear weather. The NMVP-integrated PTO enables maintaining temperature within ≈1 °C on the skin under sunlight relative to indoor measurement, whereas the normally used, black encapsulated PTO shows over 40 °C owing to solar absorption. The heated PTO exhibits an inaccurate tissue oxygen saturation (StO) value of ≈67% compared with StO in a normal state (i.e., ≈80%). However, the thermally protected PTO presents reliable StO of ≈80%. This successful demonstration provides a feasible strategy of thermal management in wearable devices for outdoor applications.
Topics: Body Temperature Regulation; Cold Temperature; Humans; Monitoring, Physiologic; Oximetry; Oxygen; Signal Processing, Computer-Assisted; Skin Temperature; Wireless Technology
PubMed: 34026462
DOI: 10.1002/advs.202004885 -
Sensors (Basel, Switzerland) Aug 2020Muscle oximetry based on near-infrared spectroscopy (NIRS) and electromyography (EMG) techniques in adherent clothing might be used to monitor the muscular activity of...
Muscle oximetry based on near-infrared spectroscopy (NIRS) and electromyography (EMG) techniques in adherent clothing might be used to monitor the muscular activity of selected muscle groups while exercising. The fusion of these wearable technologies in sporting garments can allow the objective assessment of the quality and the quantity of the muscle activity as well as the continuous monitoring of exercise programs. Several prototypes integrating EMG and NIRS have been developed previously; however, most devices presented the limitations of not measuring regional muscle oxyhemoglobin saturation and did not embed textile sensors for EMG. The purpose of this study was to compare regional muscle oxyhemoglobin saturation and surface EMG data, measured under resting and dynamic conditions (treadmill run and strength exercises) by a recently developed wearable integrated quadriceps muscle oximetry/EMG system adopting smart textiles for EMG, with those obtained by using two "gold standard" commercial instrumentations for EMG and muscle oximetry. The validity and agreement between the wearable integrated muscle oximetry/EMG system and the "gold standard" instrumentations were assessed by using the Bland-Altman agreement plots to determine the bias. The results support the validity of the data provided by the wearable electronic garment developed purposely for the quadriceps muscle group and suggest the potential of using such device to measure strength and endurance exercises in vivo in various populations.
Topics: Adult; Cross-Over Studies; Electromyography; Humans; Male; Oximetry; Quadriceps Muscle; Textiles; Thigh; Wearable Electronic Devices; Young Adult
PubMed: 32824976
DOI: 10.3390/s20174664 -
Acta Ophthalmologica Nov 2019To study the retinal vascular oxygen saturation in amblyopic eyes and compare them to unaffected fellow eyes and eyes of normal subjects. (Comparative Study)
Comparative Study Observational Study
PURPOSE
To study the retinal vascular oxygen saturation in amblyopic eyes and compare them to unaffected fellow eyes and eyes of normal subjects.
METHODS
A total of 32 amblyopic, 24 normal and 13 fellow eyes of patients below age of 18 were enrolled in this prospective observation study. Retinal oximetry was performed using the Oxymap T1 retinal oximeter. Retinal vascular oxygen saturations and diameters were compared between amblyopic eyes, normal eyes and unaffected fellow eyes.
RESULTS
The average age was 8.6 years in the amblyopia group (M:F 16:16) and 10.9 years in the normal group (M:F 7:5; p = 0.024). Median corrected distance visual acuity in the amblyopia group was 20/50; it was 20/20 in the other groups (p < 0.001). The average arteriolar and venous saturation in the amblyopia, normal and fellow group was 84.5% (95% CI: 82.6-86.4), 83.2% (95% CI: 80.7-85.6) and 80.8% (95% CI: 78.6-82.9) and 51.9% (95% CI: 50.4-53.4), 50.8% (95% CI: 48.2-53.4) and 49.3% (95% CI: 45.7-52.9). There was no statistically significant difference between the saturation values of the amblyopia group and the controls, however, significantly higher values were found in the amblyopia group compared to the fellow group for arteriolar and venous saturations (p = 0.013; p = 0.005). Arteriolar and venous diameters showed no significant difference between groups.
CONCLUSION
Amblyopic eyes showed higher mean oxygen saturations than the fellow eyes. This observation could be due to altered neuronal activity or could be due to a measurement artefact due to alterations in retinal reflectivity.
Topics: Adolescent; Amblyopia; Child; Cross-Sectional Studies; Female; Humans; Male; Oximetry; Oxygen; Pilot Projects; Prospective Studies; Retina; Tomography, Optical Coherence
PubMed: 30843376
DOI: 10.1111/aos.14075 -
Resuscitation May 2020Flow disruptions (FDs) are deviations from the progression of care that compromise safety and efficiency of a specific process. The study aim was to identify the impact... (Observational Study)
Observational Study
AIM
Flow disruptions (FDs) are deviations from the progression of care that compromise safety and efficiency of a specific process. The study aim was to identify the impact of FDs during neonatal resuscitation and determine their association with key process and outcome measures.
METHODS
Prospective observational study of video recorded delivery room resuscitations of neonates <32 weeks gestational age. FDs were classified using an adaptation of Wiegmann's FD tool. The primary outcome was target oxygenation saturation achievement at 5 min. Secondary outcomes included achieving target saturation at 10 min, time to positive pressure ventilation for initially apnoeic/bradycardic neonates, time to electrocardiogram signal, time to pulse oximetry signal, and time to stable airway. Multivariable logistic regression assessed association between FDs and achieving target saturations adjusting for gestational age and leader. Associations between FDs and time to event outcomes were assessed using Cox proportional hazards models.
RESULTS
Between 10/2017-7/2018, 32 videos were included. A mean of 52.6 FDs (standard deviation 17.9) occurred per resuscitation. Extraneous FDs were the most common FDs. FDs were associated with an adjusted odds ratio of 0.92 (95% confidence interval [CI] 0.80-1.05) of achieving target saturation at 5 min and 0.94 (95% CI 0.84-1.05) at 10 min. There was no significant evidence to show FDs were associated with time to event outcomes.
CONCLUSIONS
FDs occurred frequently during neonatal resuscitation. Measuring FDs is a feasible method to assess the impact of human factors in the delivery room and identify modifiable factors and practices to improve patient care.
Topics: Delivery Rooms; Female; Humans; Infant, Newborn; Intermittent Positive-Pressure Ventilation; Oximetry; Positive-Pressure Respiration; Pregnancy; Resuscitation
PubMed: 32194162
DOI: 10.1016/j.resuscitation.2020.02.037 -
Pediatric Pulmonology Jan 2022Pulse oximetry monitoring is prescribed to children receiving home oxygen for chronic medical conditions associated with hypoxemia. Although home pediatric pulse...
INTRODUCTION
Pulse oximetry monitoring is prescribed to children receiving home oxygen for chronic medical conditions associated with hypoxemia. Although home pediatric pulse oximetry is supported by national organizations, there is a lack of guidelines outlining indications and prescribing parameters.
METHODS
A mixed-methods analysis of pediatric home pulse oximetry orders prescribed through the institutional home healthcare provider at a large US children's hospital 6/2018-7/2019 was retrospectively reviewed to determine prescribed alarm parameter limits and recommended interventions. Semi-structured qualitative interviews with pediatric providers managing patients receiving home oxygen and pulse oximetry were conducted to identify opportunities to improve home pulse oximetry prescribing practices. Interviews were analyzed using a modified content analysis approach to identify recurring themes.
RESULTS
A total of 368 children received home pulse oximetry orders. Orders were most frequently prescribed on noncardiac medical floors (32%). Attending physicians were the most frequent ordering providers (52%). Frequency of use was prescribed in 96% of orders, however, just 70% were provided with specific instructions for interventions when alarms occurred. Provider role and clinical setting were significantly associated with the presence of a care plan. Provider interviews identified opportunities for improvement with the device, management of alarm parameter limits, and access to home monitor data.
DISCUSSION
This study demonstrated significant variability in home pulse oximetry prescribing practices. Provider interviews highlighted the importance of the provider-patient relationship and areas for improvement. There is an opportunity to create standardized guidelines that optimize the use of home monitoring devices for patients, families, and pulmonary providers.
Topics: Child; Hospitals, Pediatric; Humans; Monitoring, Physiologic; Oximetry; Patient Discharge; Retrospective Studies
PubMed: 34633759
DOI: 10.1002/ppul.25722 -
Journal of Biomedical Informatics Feb 2022Uncontrolled hemorrhage is a leading cause of preventable death among patients with trauma. Early recognition of hemorrhage can aid in the decision to administer blood...
Uncontrolled hemorrhage is a leading cause of preventable death among patients with trauma. Early recognition of hemorrhage can aid in the decision to administer blood transfusion and improve patient outcomes. To provide real-time measurement and continuous monitoring of hemoglobin concentration, the non-invasive and continuous hemoglobin (SpHb) measurement device has drawn extensive attention in clinical practice. However, the accuracy of such a device varies in different scenarios, so the use is not yet widely accepted. This article focuses on using statistical nonparametric models to improve the accuracy of SpHb measurement device by considering measurement bias among instantaneous measurements and individual evolution trends. In the proposed method, the robust locally estimated scatterplot smoothing (LOESS) method and the Kernel regression model are considered to address those issues. Overall performance of the proposed method was evaluated by cross-validation, which showed a substantial improvement in accuracy with an 11.3% reduction of standard deviation, 23.7% reduction of mean absolute error, and 28% reduction of mean absolute percentage error compared to the original measurements. The effects of patient demographics and initial medical condition were analyzed and deemed to not have a significant effect on accuracy. Because of its high accuracy, the proposed method is highly promising to be considered to support transfusion decision-making and continuous monitoring of hemoglobin concentration. The method also has promise for similar advancement of other diagnostic devices in healthcare.
Topics: Hematologic Tests; Hemoglobins; Hemorrhage; Humans; Oximetry
PubMed: 34906736
DOI: 10.1016/j.jbi.2021.103975 -
Critical Care Medicine Feb 2022To assess disparities in hypoxemia detection by pulse oximetry across self-identified racial groups and associations with clinical outcomes.
OBJECTIVES
To assess disparities in hypoxemia detection by pulse oximetry across self-identified racial groups and associations with clinical outcomes.
DESIGN
Observational cohort study from May 5, 2018, to December 31, 2020.
SETTING
Three academic medical centers in the United States.
PATIENTS
Adults greater than or equal to 18 years who self-identified as White, Black, Asian, or American Indian admitted to the ICU or undergoing surgery during inpatient hospitalization with simultaneous measurements of pulse oximetry-estimated oxygen saturation and arterial blood gas-derived oxygen saturation.
INTERVENTIONS
None.
MEASUREMENTS AND MAIN RESULTS
Multivariable models were employed to assess the relationships between race, occult hypoxemia (i.e., arterial blood gas-derived oxygen saturation < 88% despite pulse oximetry-estimated oxygen saturation ≥ 92%), and clinical outcomes of hospital mortality and hospital-free days. One-hundred twenty-eight-thousand two-hundred eighty-five paired pulse oximetry-estimated oxygen saturation-arterial blood gas-derived oxygen saturation measurements were included from 26,603 patients. Pulse oximetry-estimated oxygen saturation on average overestimated arterial blood gas-derived oxygen saturation by 1.57% (1.54-1.61%). Black, Asian, and American Indian patients were more likely to experience occult hypoxemia during hospitalization (estimated probability 6.2% [5.1-7.6%], 6.6% [4.9-8.8%], and 6.6% [4.4-10.0%], respectively) compared with White patients (3.6% [3.4-3.8%]). Black patients had increased odds of occult hypoxemia compared with White patients after adjustment (odds ratio, 1.65; 1.28-2.14; p < 0.001). Differences in occult hypoxemia between Asian and American Indian patients compared with White patients were not significant after adjustment (odds ratio, 1.53; 0.95-2.47; p = 0.077 and odds ratio, 1.31; 0.80-2.16; p = 0.288, respectively). Occult hypoxemia was associated with increased odds of mortality in surgical (odds ratio, 2.96; 1.20-7.28; p = 0.019) and ICU patients (1.36; 1.03-1.80; p = 0.033). Occult hypoxemia was associated with fewer hospital-free days in surgical (-2.5 d [-3.9 to -1.2 d]; p < 0.001) but not ICU patients (0.4 d [-0.7 to 1.4 d]; p = 0.500).
CONCLUSIONS
Occult hypoxemia is more common in Black patients compared with White patients and is associated with increased mortality, suggesting potentially important outcome implications for undetected hypoxemia. It is imperative to validate pulse oximetry with expanded racial inclusion.
Topics: Academic Medical Centers; Aged; Arizona; Cohort Studies; Female; Florida; Humans; Hypoxia; Male; Middle Aged; Minnesota; Outcome Assessment, Health Care; Oximetry; Oxygen; Racial Groups; Self Report; Skin Pigmentation
PubMed: 35100193
DOI: 10.1097/CCM.0000000000005394