scholarly journals Estimated Pao 2: A Continuous and Noninvasive Method to Estimate Pao 2 and Oxygenation Index

2021 ◽  
Vol 3 (10) ◽  
pp. e0546
Author(s):  
Michaël Sauthier ◽  
Gaurav Tuli ◽  
Philippe A. Jouvet ◽  
John S. Brownstein ◽  
Adrienne G. Randolph
Keyword(s):  
Oxygenation Index ◽  
Noninvasive Method

scholarly journals Effect of PEMF on Muscle Oxygenation during Cycling: A Single-Blind Controlled Pilot Study

2021 ◽  
Vol 11 (8) ◽  
pp. 3624
Author(s):  
Aurelio Trofè ◽  
Milena Raffi ◽  
David Muehsam ◽  
Andrea Meoni ◽  
Francesco Campa ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Slow Component ◽  
Local Level ◽  
Lactate Concentration ◽  
Oxygenation Index ◽  
State Level ◽  
Acute Effect ◽  
Primary Component ◽  
Muscle Oxygenation ◽  
Oxygen Kinetics

Pulsed electromagnetic fields (PEMFs) are used as non-invasive tools to enhance microcirculation and tissue oxygenation, with a modulatory influence on the microvasculature. This study aimed to measure the acute effect of PEMF on muscle oxygenation and its influence on pulmonary oxygen kinetics during exercise. Eighteen male cyclists performed, on different days, a constant-load exercise in both active (ON) and inactive (OFF) PEMF stimulations while deoxyhemoglobin and pulmonary oxygen kinetics, total oxygenation index, and blood lactate were collected. PEMF enhanced muscle oxygenation, with higher values of deoxyhemoglobin both at the primary component and at the steady-state level. Moreover, PEMF accelerated deoxyhemoglobin on-transition kinetic, with a shorter time delay, time constant, and mean response time than the OFF condition. Lactate concentration was higher during stimulation. No differences were found for total oxygenation index and pulmonary oxygen kinetics. Local application of a precise PEMF stimulation can increase the rate of the muscle O2 extraction and utilization. These changes were not accompanied by faster oxygen kinetics, reduced oxygen slow component, or reduced blood lactate level. It seems that oxygen consumption is more influenced by exercise involving large muscle mass like cycling, whereas PEMF might only act at the local level.

scholarly journals Engineering digital biomarkers of interstitial glucose from noninvasive smartwatches

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Brinnae Bent ◽  
Peter J. Cho ◽  
Maria Henriquez ◽  
April Wittmann ◽  
Connie Thacker ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Data Driven ◽  
Self Management ◽  
Noninvasive Method ◽  
Medical Interventions ◽  
Interstitial Glucose ◽  
Using Data ◽  
Glucose Prediction ◽  
Digital Biomarkers

AbstractPrediabetes affects one in three people and has a 10% annual conversion rate to type 2 diabetes without lifestyle or medical interventions. Management of glycemic health is essential to prevent progression to type 2 diabetes. However, there is currently no commercially-available and noninvasive method for monitoring glycemic health to aid in self-management of prediabetes. There is a critical need for innovative, practical strategies to improve monitoring and management of glycemic health. In this study, using a dataset of 25,000 simultaneous interstitial glucose and noninvasive wearable smartwatch measurements, we demonstrated the feasibility of using noninvasive and widely accessible methods, including smartwatches and food logs recorded over 10 days, to continuously detect personalized glucose deviations and to predict the exact interstitial glucose value in real time with up to 84% and 87% accuracy, respectively. We also establish methods for designing variables using data-driven and domain-driven methods from noninvasive wearables toward interstitial glucose prediction.

scholarly journals Pathogenetic and predictive value of biomarkers in patients with ALI and lower severity of illness: results from two clinical trials

2012 ◽  
Vol 303 (8) ◽  
pp. L634-L639 ◽  
Author(s):  
Ashish Agrawal ◽  
Hanjing Zhuo ◽  
Sandra Brady ◽  
Joseph Levitt ◽  
Jay Steingrub ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Clinical Outcomes ◽  
Predictive Value ◽  
Secondary Analysis ◽  
Activated Protein C ◽  
Oxygenation Index ◽  
Severity Of Illness ◽  
Plasminogen Activator Inhibitor ◽  
High Plasma ◽  
Plasminogen Activator Inhibitor 1

Plasma and bronchoalveolar lavage (BAL) biomarkers related to the pathogenesis of acute lung injury (ALI) have previously been associated with poorer clinical outcomes and increased disease severity among patients with ALI. Whether these biomarkers have predictive value in a less severely ill population that excludes septic patients with high APACHE II scores is currently unknown. We tested the association of plasma and BAL biomarkers with physiological markers of ALI severity or clinically relevant outcomes in a secondary analysis of a clinical trial of activated protein C for the treatment of ALI. Plasma plasminogen activator inhibitor-1 (PAI-1) and mini-BAL protein were both significantly associated with increased oxygenation index ( P = 0.02 and 0.01, respectively), whereas there was a trend toward an association between IL-6 and oxygenation index ( P = 0.057). High plasma IL-6, thrombomodulin, and mini-BAL protein were all significantly associated with fewer ventilator-free days (VFDs) ( P = 0.01, 0.01, and 0.05, respectively); no markers were associated with mortality, but we hypothesized that this was due to the small size of our cohort and the low death rate. To confirm these associations in a larger sample, we identified a restricted cohort of patients from the ARDS Network ALVEOLI study with similar baseline characteristics. We retested the associations of the significant biomarkers with markers of severity and clinical outcomes and studied IL-8 as an additional biomarker given its important predictive value in prior studies. In this restricted cohort, IL-6 was significantly associated with oxygenation index ( P = 0.02). Both IL-6 and IL-8 were associated with decreased VFDs and increased 28-day mortality. Future studies should be focused on examining larger numbers of patients with less severe ALI to further test the relative predictive value of plasma and mini-BAL biomarkers for clinically relevant outcomes, including VFDs and mortality, and for their prospective utility in risk stratification for future clinical trials.

Which common NIRS variable reflects muscle estimated lactate threshold most closely?

2006 ◽  
Vol 31 (5) ◽  
pp. 612-620 ◽  
Author(s):  
Lixin Wang ◽  
Takahiro Yoshikawa ◽  
Taketaka Hara ◽  
Hayato Nakao ◽  
Takashi Suzuki ◽  
...  
Keyword(s):  
Lactate Threshold ◽  
Near Infrared ◽  
Ventilatory Threshold ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Oxygenation Index ◽  
Muscle Lactate ◽  
Tissue Oxygenation Index ◽  
The Mean ◽  
Tissue Hemoglobin

Various near-infrared spectroscopy (NIRS) variables have been used to estimate muscle lactate threshold (LT), but no study has determined which common NIRS variable best reflects muscle estimated LT. Establishing the inflection point of 2 regression lines for deoxyhaemoglobin (ΔHHbi.p.), oxyhaemoglobin (ΔO2Hbi.p.), and tissue oxygenation index (TOIi.p.), as well as for blood lactate concentration, we then investigated the relationships between NIRS variables and ventilatory threshold (VT), LT, or maximal tissue hemoglobin index (nTHImax) during incremental cycling exercise. ΔHHbi.p. and TOIi.p. could be determined for all 15 subjects, but ΔO2Hbi.p. was determined for only 11 subjects. The mean absolute values for the 2 measurable slopes of the 2 continuous linear regression lines exhibited increased changes in 3 NIRS variables. The workload and VO2 at ΔO2Hbi.p. and nTHImax were greater than those at VT, LT, ΔHHbi.p., and TOIi.p.. For workload and VO2, ΔHHbi.p. was correlated with VT and LT, whereas ΔO2Hbi.p. was correlated with nTHImax, and TOIi.p. with VT and nTHImax. These findings indicate that ΔO2Hb strongly corresponds with local perfusion, and TOI corresponds with both local perfusion and deoxygenation, but that ΔHHb can exactly determine deoxygenation changes and reflect O2 metabolic dynamics. The finding of strongest correlations between ΔHHb and VT or LT indicates that ΔHHb is the best variable for muscle LT estimation.

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