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Purpose: The purpose of this study was to evaluate the accuracy of peripheral oxygen saturation (SpO2) measurements from Polar Elixir™ pulse oximetry technology compared with arterial oxygen saturation (SaO2) measurements during acute stepwise steady-state inspired hypoxia at rest. A post hoc objective was to determine if SpO2 measurements could be improved by recalibrating the Polar Elixir™ algorithm with SaO2 values from a random subset of participants. Methods: The International Organization for Standardization (ISO) protocol (ISO 80601-2-61:2017) for evaluating the SpO2 accuracy of pulse oximeter equipment was followed whereby five plateaus of SaO2 between 70% and 100%were achieved using stepwise reductions in inspired O2 during supine rest. Blood samples drawn through a radial arterial catheter from 25 participants were first used to compare SaO2 with SpO2 measurements from Polar Elixir™. Then the Polar Elixir™ algorithm was recalibrated using SaO2 data from 13 random participants, and SpO2 estimates were recalculated for the other 12 participants. For SaO2 values between 70%and 100%, root mean square error, intraclass correlation coefficients (ICC), Pearson correlations, and Bland--Altman plots were used to assess the accuracy, agreement, and strength of relationship between SaO2 values and SpO2 values from Polar Elixir™. Results: The initial root mean square error for Polar Elixir™ was 4.13%. After recalibrating the algorithm, the RMSE was improved to 2.67%. The ICC revealed excellent levels of agreement between SaO2 and Polar Elixir™SpO2 values both before (ICC(1,3) = 0.837, df = 574, P < 0.001) and after (ICC(1,3) = 0.942, df = 287, P < 0.001) recalibration. Conclusions: Relative to ISO standards, Polar Elixir™ yielded accurate SpO2 measurements during stepwise inspired hypoxia at restwhen comparedwith SaO2 values, which were improved by recalibrating the algorithm using a subset of the SaO2 data. [ABSTRACT FROM AUTHOR]

The effects of elexacaftor/tezacaftor/ivacaftor (ETI) on respiratory outcomes for people with cystic fibrosis (CF) were demonstrated by several clinical trials, mainly based on simple spirometry. However, gains in lung function may vary greatly between patients, and predictors of FEV 1 change after treatment have yet to be defined. Which ventilatory parameters are involved in the heterogeneity of FEV 1 change after 12-month ETI treatment in people with CF and advanced lung disease? This was a multicenter, observational, prospective cohort study at two major CF centers in Italy. We enrolled 47 adults with CF and advanced lung disease (FEV 1 < 40% or actively listed for lung transplant) who started ETI treatment between December 2019 and December 2021. At treatment initiation and after 12 months, patients underwent body plethysmography. Values were compared at the two time points. To assess the relationship between baseline plethysmography measurements and treatment-induced changes in FEV 1 , we used the Spearman rank correlation coefficient (r s) and median quantile regressions. After 12 months of ETI treatment, there was a significant increase in FEV 1 % predicted from a median value of 36.0 (25th-75th percentile, 33-39) to 52 (25th-75th percentile, 43-61) (P <.001). Inspiratory capacity/total lung capacity (TLC) ratio also increased from 32.0 (25th-75th percentile, 28.6-36.9) to 36.3 (25th-75th percentile, 33.4-41.3) (P <.001). Specific airway resistance decreased from 263 (25th-75th percentile, 182-405) to 207 (25th-75th percentile, 120-258) (P <.001). Functional residual capacity/TLC ratio decreased from 68.2 (25th-75th percentile, 63.3-71.9) to 63.9 (25th-75th percentile, 58.8-67.1) (P <.001), and residual volume/TLC ratio decreased from 53.1 (25th-75th percentile, 48.3-59.4) to 45.6 (25th-75th percentile, 39.4-49.8) (P <.001). Changes in FEV 1 % predicted negatively correlated with baseline functional residual capacity/TLC ratio (r s = −0.38, P =.009) and residual volume/TLC ratio (r s = −0.42, P =.004). After adjustment for age at treatment initiation and cystic fibrosis transmembrane conductance regulator genotype, we estimated that for each 10-unit increase in baseline residual volume/TLC ratio, the expected median change in FEV 1 decreased by 2.3 (95% CI, −5.8 to −0.8). ETI was associated with improvements in both static and dynamic volumes in people with CF and advanced lung disease. Heterogeneity in FEV 1 % predicted change after 12 months of treatment may be predicted by the severity of hyperinflation at baseline. [ABSTRACT FROM AUTHOR]

Blood lactate is a marker of tissue hypoxia while capillary refill time (CRT) is a surrogate of tissue perfusion. Measuring these parameters is recommended for assessing circulatory status and guiding resuscitation. However, blood lactate is not widely available in African emergency departments. Additionally, CRT assessment faces challenges related to its precision and reproducibility. This study aims to evaluate the accuracy of visual CRT(V-CRT) compared to plethysmographic CRT (P-CRT) in predicting lactate levels among septic patients. This prospective observational study enrolled consecutive patients with sepsis or septic shock over a 6-month period from a tertiary hospital in Marrakech, Morroco. V-CRT and P-CRT were evaluated upon admission, and simultaneous measurements of arterial lactate levels were obtained. The precision of V-CRT and P-CRT in predicting arterial lactate was assessed using ROC curve analysis. Forty-three patients aged of 64±15 years, of whom 70 % were male, were included in the study. Of these, 23 patients (53 %) had sepsis, and 20 patients (47 %) experienced septic shock. Both V-CRT and P-CRT demonstrated statistically significant correlations with arterial lactate, with correlation coefficients of 0.529 (p < 0.0001) and 0.517 (p = 0.001), respectively. ROC curve analysis revealed that V-CRT exhibited satisfactory accuracy in predicting arterial lactate levels >2 mmol/l, with an area under the curve (AUC) of 0.8 (95 % CI=0.65 – 0.93; p < 0.0001). The prediction ability of P-CRT was lower than V-CRT with an AUC of 0.73 (95 % CI: 0.57–0.89; p = 0.043). The optimal thresholds were determined as 3.4 s for V-CRT (sensitivity = 90 %, specificity = 58 %) and 4.1 s for P-CRT (sensitivity = 85 %, specificity = 62 %). These findings suggest that the plethysmographic evaluation did not improve the accuracy of CRT for predicting lactate level. However, V-CRT may still serve as a viable surrogate for lactate in septic patients in low-income settings. [ABSTRACT FROM AUTHOR]

BACKGROUND: High-flow nasal cannula (HFNC) systems employ different methods to provide aerosol to patients. This study compared delivery efficiency, particle size, and regional deposition of aerosolized bronchodilators during HFNC in neonatal, pediatric, and adult upper-airway and lung models between a proximal aerosol adapter and distal aerosol circuit chamber. METHODS: A filter was connected to the upper airway to a spontaneously breathing lung model. Albuterol was nebulized using the aerosol adapter and circuit at different clinical flow settings. The aerosol mass deposited in the upper airway and lung was quantified. Particle size was measured with a laser diffractometer. Regional deposition was assessed with a gamma camera at each nebulizer location and patient model with minimum flow settings. RESULTS: Inhaled lung doses ranged from 0.2-0.8% for neonates, 0.2-2.2% for the small child, and 0.5-5.2% for the adult models. Neonatal inhaled lung doses were not different between the aerosol circuit and adapter, but the aerosol circuit showed marginally greater lung doses in the pediatric and adult patient models. Impacted aerosols and condensation in the non-heated HFNC and aerosol delivery components contributed to the dispersion of coarse liquid droplets, high deposition (11-44%), and occlusion of the supine neonatal upper airway. In contrast, the upright pediatric and adult upper-airway models had minimal deposition (0.3-7.0%) and high fugitive losses (~24%) from liquid droplets leaking out of the nose. The high impactive losses in the aerosol adapter (56%) were better contained than in the aerosol circuit, resulting in less cannula sputter (5% vs 22%), fewer fugitive losses (18% vs 24%), and smaller inhaled aerosols (5 µm vs 13 µm). CONCLUSIONS: The inhaled lung dose was low (1-5%) during HFNC. Approaches that streamline aerosol delivery are needed to provide safe and effective therapy to patients receiving aerosolized medications with this HFNC system. [ABSTRACT FROM AUTHOR]

Background: Currently, there is conflicting information and guidance on the effective management of Alpha 1 Antitrypsin Deficiency (AATD). Establishing a consensus of assessment and disease management specific to AATD is important for achieving a standardized treatment pathway and for improving patient outcomes. Here, we aim to utilize the Delphi method to establish a European consensus for the assessment and management of patients with severe AATD. Methods: Two rounds of a Delphi survey were completed online by members of the European Alpha-1 Research Collaboration (EARCO). Respondents were asked to indicate their agreement with proposed statements for patients with no respiratory symptoms, stable respiratory disease, and worsening respiratory disease using a Likert scale of 1–7. Levels of agreement between respondents were calculated using a weighted average. Results: Round 1 of the Delphi survey was sent to 103 members of EARCO and 38/103 (36.9%) pulmonologists from across 15 countries completed all 109 questions. Round 2 was sent to all who completed Round 1 and 36/38 (94.7%) completed all 79 questions. Responses regarding spirometry, body plethysmography, high-resolution computed tomography, and the initiation of augmentation therapy showed little variability among physicians, but there was discordance among other aspects, such as the use of low-dose computed tomography in both a research setting and routine clinical care. Conclusions: These results provide expert opinions for the assessment and monitoring of patients with severe AATD, which could be used to provide updated recommendations and standardized treatment pathways for patients across Europe. [ABSTRACT FROM AUTHOR]

Introduction: High blood pressure (HBP) is an independent, modifiable driver of cardiovascular (CV) morbidity and mortality. Nocturnal hypertension and non-dipping of blood pressure (NdBP)may be earlymarkers of HBP. Similar to patients with NdBP, individuals with non-dipping of heart rate (NdHR) during sleep have an increased risk of CV disease, CV events, and CV-related mortality. The aim of this analysis was to evaluate if cardiopulmonary coupling (CPC) analysis-derived sleep states [stable/unstable non-rapid eyemovement (NREM) sleep] and concomitant heart rate (HR) changes can provide information about nocturnal blood pressure (BP). Method: Plethysmogram (pleth) signals from the HeartBEAT study (NCT01086800) were analyzed for CPC sleep states. Included in the analysis are sleep recordings from participants with acceptable pleth-signal quality at baseline (n = 302) and follow-up (n = 267), all having confirmed CV disease or CV-disease risk factors. The participants had a high prevalence of obstructive sleep apnea (OSA), 98.4% with moderate-OSA [apnea-hypopnea index (AHI) ≥ 15) and 29.6% severe OSA (AHI ≥ 30). A "heart-rate module" was created to evaluate the utility of identifying patients more likely to have BP dipping during sleep. Patients who did not have a decrease of ≥10% in their BP from wake to sleep were defined as NdBP and NdHR if their heart rate during stable-NREM sleep was higher than during unstable-NREM sleep. Results: The most significant difference in minimum HR (HRmin) was observed when comparing BP dippers [56 ± 4 beats per minute (BPM)] and non-BP dippers (59 ± 4 BPM; p < 0.0001) during diastolic blood pressure in stable-NREM sleep. Higher HRmin were associated with an increased likelihood of being a non-dipper, with the strongest relationship with diastolic BP and stable-NREM sleep. Every increase of 1 BPM during stable-NREM sleep was associated with an ~4.4% increase in the probability of NdBP (p = 0.001). Subjects with NdHR have higher mean BP during sleep and wake periods than HR dippers. When continuous positive airway pressure therapy is efficacious, and a dipping pattern is achieved--physical and mental health is improved. Conclusion: HR analytics in relation to the sleep period and the CPC spectrogram-estimated sleep states can provide novel and potentially clinically useful information on autonomic health. HR dipping (or not) may be a useful screener of BP dipping or non-dipping to identify individuals who may benefit from a formal assessment of 24-h ambulatory BP. Such a stepped approach may enable a more practical and applicable approach to diagnosing HBP. [ABSTRACT FROM AUTHOR]

We propose a novel approach for predicting stress severity by measuring sleep phasic heart rate variability (HRV) using a smart device. This device can potentially be applied for stress self‐screening in large populations. Using a Holter electrocardiogram (ECG) and a Huawei smart device, we conducted 24‐h dual recordings of 159 medical workers working regular shifts. Based on photoplethysmography (PPG) and accelerometer signals acquired by the Huawei smart device, we sorted episodes of cyclic alternating pattern (CAP; unstable sleep), non‐cyclic alternating pattern (NCAP; stable sleep), wakefulness, and rapid eye movement (REM) sleep based on cardiopulmonary coupling (CPC) algorithms. We further calculated the HRV indices during NCAP, CAP and REM sleep episodes using both the Holter ECG and smart‐device PPG signals. We later developed a machine learning model to predict stress severity based only on the smart device data obtained from the participants along with a clinical evaluation of emotion and stress conditions. Sleep phasic HRV indices predict individual stress severity with better performance in CAP or REM sleep than in NCAP. Using the smart device data only, the optimal machine learning‐based stress prediction model exhibited accuracy of 80.3 %, sensitivity 87.2 %, and 63.9 % for specificity. Sleep phasic heart rate variability can be accurately evaluated using a smart device and subsequently can be used for stress predication. [ABSTRACT FROM AUTHOR]

Simple Summary: The stress load of cats undergoing lung function diagnostics using barometric whole-body plethysmography has not yet been investigated. In this study, a feline stress score was used to determine the stress level of healthy cats over a 30 min time period during plethysmographic measurement; in addition, the correlation with measured parameters was evaluated. The stress levels of the majority of the 48 cats studied were increased at the beginning of measurements and decreased significantly over time. There was a significant correlation between most measurement parameters and the total stress score. Although the barometric whole-body plethysmography is considered to be a particularly gentle method, most cats initially experienced moderate stress. The stress level must be taken into account when interpreting the measured parameters. Barometric whole-body plethysmography (BWBP) is considered to be a particularly gentle method of assessing lung function in cats. However, there have been no studies to date investigating the stress experienced by cats during measurements. The prospective study included 48 healthy adult cats. Each cat was measured in the plethysmographic chamber for a total of 30 min and stress levels were determined every 10 min using a stress ethogram. At the beginning of measurements, 75% of cats were assessed as tense. Over the three time periods, a significant (p < 0.001) reduction in the total stress score was observed. In addition, all measurement parameters correlated significantly with the stress score, with the exception of enhanced pause and tidal volume. It can therefore be assumed that cats will initially experience stress during examination in the plethysmographic chamber, but stress will decrease significantly over time. As the stress level correlates with many measurement parameters, this should be taken into account when interpreting the results. [ABSTRACT FROM AUTHOR]

This article discusses a study on the prevalence of isolated inter-scalene compression in patients with suspected thoracic outlet syndrome (TOS). The study used photoplethysmography to analyze arterial and venous results in 116 subjects. The results showed that a significant proportion of limbs had isolated arterial inflow or venous outflow impairment. The authors suggest that this method of analysis can help differentiate between arterial and venous compression and potentially aid in the evaluation and treatment of TOS. Additionally, the document includes a study on TOS using photoplethysmography to assess hemodynamic responses, which found that symptoms were present in more than half of the limbs with apparently normal responses. The document also provides a list of references related to TOS, covering various aspects of the condition. [Extracted from the article]

Summary CDKL5 deficiency disorder is a rare genetic disease caused by mutations in the CDKL5 gene. Central apneas during wakefulness have been reported in patients with CDKL5 deficiency disorder. Studies on CDKL5‐knockout mice, a CDKL5 deficiency disorder model, reported sleep apneas, but it is still unclear whether these events are central (central sleep apnea) or obstructive (obstructive sleep apnea) and may be related to alterations of brain circuits that modulate breathing rhythm. This study aimed to discriminate central sleep apnea and obstructive sleep apnea in CDKL5‐knockout mice, and explore changes in the somatostatin neurons expressing high levels of neurokinin‐1 receptors within the preBötzinger complex. Ten adult male wild‐type and 12 CDKL5‐knockout mice underwent electrode implantation for sleep stage discrimination and diaphragmatic activity recording, and were studied using whole‐body plethysmography for 7 hr during the light (resting) period. Sleep apneas were categorised as central sleep apnea or obstructive sleep apnea based on the recorded signals. The number of somatostatin neurons in the preBötzinger complex and their neurokinin‐1 receptors expression were assessed through immunohistochemistry in a sub‐group of animals. CDKL5‐knockout mice exhibited a higher apnea occurrence rate and a greater prevalence of obstructive sleep apnea during rapid eye movement sleep, compared with wild‐type, whereas no significant difference was observed for central sleep apnea. Moreover, CDKL5‐knockout mice showed a reduced number of somatostatin neurons in the preBötzinger complex, and these neurons expressed a lower level of neurokinin‐1 receptors compared with wild‐type controls. These findings underscore the pivotal role of CDKL5 in regulating normal breathing, suggesting its potential involvement in shaping preBötzinger complex neural circuitry and controlling respiratory muscles during sleep. [ABSTRACT FROM AUTHOR]

The aging population in Canada has been increasing continuously throughout the past decades. Amongst this demographic, around 11% suffer from some form of cognitive decline. While diagnosis through traditional means (i.e., Magnetic Resonance Imagings (MRIs), positron emission tomography (PET) scans, cognitive assessments, etc.) has been successful at detecting this decline, there remains unexplored measures of cognitive health that could reduce stress and cost for the elderly population, including approaches for early detection and preventive methods. Such efforts could additionally contribute to reducing the pressure and stress on the Canadian healthcare system, as well as improve the quality of life of the elderly population. Previous evidence has demonstrated emotional facial expressions being altered in individuals with various cognitive conditions such as dementias, mild cognitive impairment, and geriatric depression. This review highlights the commonalities among these cognitive health conditions, and research behind the contactless assessment methods to monitor the health and cognitive well-being of the elderly population through emotion expression. The contactless detection approach covered by this review includes automated facial expression analysis (AFEA), electroencephalogram (EEG) technologies and heart rate variability (HRV). In conclusion, a discussion of the potentials of the existing technologies and future direction of a novel assessment design through fusion of AFEA, EEG and HRV measures to increase detection of cognitive decline in a contactless and remote manner will be presented. [ABSTRACT FROM AUTHOR]

Objective: Orthostatic hypotension is a frequently encountered problem after sitting position. The aim of our study was to evaluate the intravascular volume status with passive leg-raising maneuver (PLRM), vena cava inferior (VCI) diameter measurements and plethysmographic variability index- plethysmographic waveform amplitude (∆Ppleth) before sitting position and to investigate the effect of these on predicting hemodynamic changes that may develop after sitting position. Methods: Fifty-three patients undergoing arthroscopic shoulder surgery under general anesthesia, aged 18-65, ASA I-II, were included in this prospective study. Mechanical ventilation was commenced with tidal volume of 6-8 mL kg-1, 5 cm H2O of PEEP. Heart rates, blood pressure and manually measured plethysmographic waveform amplitudes were recorded and VCI-distensibility index (VCI-DI) was calculated. Measurements were repeated after performing PLRM. Correlation of hemodynamic changes, observed after patients were placed in sitting position, with VCI-DI and variations in the ∆Ppleth was evaluated. Results: After induction, VCI-DI was >18% in 19 (35.8%) of 53 patients and in 14 (73.7%) of these, VCI-DI decreased with PLRM. In 14 (93.3%) of 15 patients with ∆Ppleth >15% after induction, ∆Ppleth decreased after PLRM. The decrease in VCI-DI and ∆Ppleth with PLRM was statistically significant (p<0.001; p<0.001). Changes in VCI-DI were found to correlate with ∆Ppleth (p<0.001). When patients were placed in sitting position, there was a significant decrease in heart rate, systolic blood pressure, mean arterial pressure (p=0.031; p<0.001), and a significant increase in ∆Ppleth (p<0.001). Conclusion: Plethysmographic waveform amplitude after PLRM can be used to predict the volume status and hemodynamic response of patients undergoing shoulder surgery in sitting position. [ABSTRACT FROM AUTHOR]

Finger photo pulse plethysmography is a simple, inexpensive and non-invasive method for measurement of arterial stiffness. The objective is to assess the correlation of arterial stiffness in low back pain subjects with lumbar disc degeneration. Thirty-four back pain patients of both sexes in age group of 30–65 were included. Anthropometric measures like height, body weight, body mass index (BMI) were included. Stiffness index (SI) and reflection index (RI) were measured from the digital volume pulse waveform. There was a negative correlation between SI/RI and no correlation between SI and RI with BMI in both sexes. A significant correlation found between weight and BMI in both sexes. Arterial stiffness may not have any influence on disc degeneration. BMI showed some influence on disc degeneration and back pain. [ABSTRACT FROM AUTHOR]

Abstract Acute respiratory distress syndrome is a severe lung condition resulting from various causes, with life-threatening consequences that necessitate intensive care. The phenomenon can be modeled in preclinical models, notably through the use of lipopolysaccharide (LPS) instillation in mice. The phenotype induced closely recapitulates the human syndrome, including pulmonary edema, leukocyte infiltration, acute inflammation, impaired pulmonary function, and histological damage. However, the experimental designs using LPS instillations are extremely diverse in the literature. This highly complicates the interpretation of the induced phenotype chronology for future study design and hinders the proper identification of the optimal time frame to assess different readouts. Therefore, the definition of the treatment window in relation to the beginning of the disease onset also presents a significant challenge to address questions or test compound efficacy. In this context, the temporality of the different readouts usually measured in the model was evaluated in both normal and neutrophil-depleted male C57bl/6 mice using LPS-induction to assess the best window for proper readout evaluation with an optimal dynamic response range. Ventilation parameters were evaluated by whole-body plethysmography and neutrophil recruitment were evaluated in bronchoalveolar lavage fluids and in lung tissues directly. Imaging evaluation of myeloperoxidase along with activity in lung lysates and fluids were compared, along with inflammatory cytokines and lung extravasation by enzyme-linked immunoassays. Moreover, dexamethasone, the gold standard positive control in this model, was also administered at different times before and after phenotype induction to assess how kinetics affected each parameter. Overall, our data demonstrate that each readout evaluated in this study has a singular kinetic and highlights the key importance of the timing between ARDS phenotype and treatment administration and/or analysis. These findings also strongly suggest that analyzes, both in-life and post-mortem should be conducted at multiple time points to properly capture the dynamic phenotype of the LPS-ARDS model and response to treatment.

Introduction: Blood lactate is a marker of tissue hypoxia while capillary refill time (CRT) is a surrogate of tissue perfusion. Measuring these parameters is recommended for assessing circulatory status and guiding resuscitation. However, blood lactate is not widely available in African emergency departments. Additionally, CRT assessment faces challenges related to its precision and reproducibility. This study aims to evaluate the accuracy of visual CRT(V-CRT) compared to plethysmographic CRT (P-CRT) in predicting lactate levels among septic patients. Methods: This prospective observational study enrolled consecutive patients with sepsis or septic shock over a 6-month period from a tertiary hospital in Marrakech, Morroco. V-CRT and P-CRT were evaluated upon admission, and simultaneous measurements of arterial lactate levels were obtained. The precision of V-CRT and P-CRT in predicting arterial lactate was assessed using ROC curve analysis. Results: Forty-three patients aged of 64±15 years, of whom 70 % were male, were included in the study. Of these, 23 patients (53 %) had sepsis, and 20 patients (47 %) experienced septic shock. Both V-CRT and P-CRT demonstrated statistically significant correlations with arterial lactate, with correlation coefficients of 0.529 (p < 0.0001) and 0.517 (p = 0.001), respectively. ROC curve analysis revealed that V-CRT exhibited satisfactory accuracy in predicting arterial lactate levels >2 mmol/l, with an area under the curve (AUC) of 0.8 (95 % CI=0.65 – 0.93; p < 0.0001). The prediction ability of P-CRT was lower than V-CRT with an AUC of 0.73 (95 % CI: 0.57–0.89; p = 0.043). The optimal thresholds were determined as 3.4 s for V-CRT (sensitivity = 90 %, specificity = 58 %) and 4.1 s for P-CRT (sensitivity = 85 %, specificity = 62 %). Conclusion: These findings suggest that the plethysmographic evaluation did not improve the accuracy of CRT for predicting lactate level. However, V-CRT may still serve as a viable surrogate for lactate in septic patients in low-income settings.

Abstract Background Currently, there is conflicting information and guidance on the effective management of Alpha 1 Antitrypsin Deficiency (AATD). Establishing a consensus of assessment and disease management specific to AATD is important for achieving a standardized treatment pathway and for improving patient outcomes. Here, we aim to utilize the Delphi method to establish a European consensus for the assessment and management of patients with severe AATD. Methods Two rounds of a Delphi survey were completed online by members of the European Alpha-1 Research Collaboration (EARCO). Respondents were asked to indicate their agreement with proposed statements for patients with no respiratory symptoms, stable respiratory disease, and worsening respiratory disease using a Likert scale of 1–7. Levels of agreement between respondents were calculated using a weighted average. Results Round 1 of the Delphi survey was sent to 103 members of EARCO and 38/103 (36.9%) pulmonologists from across 15 countries completed all 109 questions. Round 2 was sent to all who completed Round 1 and 36/38 (94.7%) completed all 79 questions. Responses regarding spirometry, body plethysmography, high-resolution computed tomography, and the initiation of augmentation therapy showed little variability among physicians, but there was discordance among other aspects, such as the use of low-dose computed tomography in both a research setting and routine clinical care. Conclusions These results provide expert opinions for the assessment and monitoring of patients with severe AATD, which could be used to provide updated recommendations and standardized treatment pathways for patients across Europe.

Introduction: The aim of the presented prospective observational study was to evaluate the effect of fistula flow on peripheral wave morphology and pulse wave velocity by means of the oscillometric Vicorder®-device with the purpose of fistula surveillance. Methods: Digitized and normalized curves of 53 haemodialysis patients at the fistula and non-fistula arm were analysed. Slope parameters and the areas under the curve of characteristic sections of pulse waves as well as the power spectrum of the pulse waves and their first and second derivatives were computed. Furthermore, the amplitude of volumetric change (AMP) was assessed. Duplex sonography served as a reference method. Results: In the comprehensive set of novel pulse wave parameters significant inter-arm differences were demonstrated and a significant delay of the systolic maximum at the fistula arm in comparison to the non-fistula arm (204 ± 3.4 vs. 162 ± 5.3 ms, p < 0.001) was proven. Unexpectedly, pulse wave velocity apparently did not differ between both arms (7.85 vs. 8.05 m/s at the fistula/non-fistula side, p = 0.942). The inter-arm differences of the slope parameters were more pronounced in forearm than in upper arm fistulas. Finally, we showed that the inter-arm difference of AMP correlated with volume flow (r = 0.326 with p = 0.017). Conclusion: Pulse waves as assessed by oscillometric pulse wave analysis have distinct features at fistula and non-fistula arms. This is due to enhanced arteriovenous flow, i.e. in both the brachial artery and the fistula vein. The analysis of those alterations has the potential to assess fistula function.

Purpose: The accuracy of heart rate measured with a wrist photoplethysmography monitor can be influenced by the tightening of the wristband, movement of arms, or kinetics of the signal (eg, steady-state exercise vs on- and off-transients). To test these hypotheses, photoplethysmographic and electrocardiographic (ECG) signals were compared. Methods: Thirty participants (50% female) randomly performed two 13′ sequences (3′ rest, 5′ submaximal-intensity exercise, and 5′ passive recovery) on a motorized treadmill and a bicycle ergometer. Heart rate was measured concomitantly with a 10-lead ECG, a chest-strap monitor, and 2 wrist photoplethysmography monitors (Polar Unite) with different tightening (free vs imposed at the maximum tolerable). Results: The level of association (r) and coefficient of variation (CV; ie, the error of measurement) of the Polar Unite versus the 10-lead ECG is affected by the tightness of the wristband (normal vs high; r =.83 and.96, CV = 16.1 and 8.1% for the treadmill, respectively; r =.71 and.97, CV = 20.3% and 6.2% for the bicycle, respectively) by the phase of the signal (transition vs steady state; r =.90 and.97, CV = 9.0% and 7.6% for the treadmill, respectively; r =.93 and.99, CV = 7.5% and 3.1% for the bicycle, respectively) and movement of arms (treadmill vs bicycle; r =.90 and.93, CV = 9.0% and 7.5% during the transition phase, respectively; r =.97 and.99, CV = 7.6% and 3.1% during the steady-state phase, respectively). Conclusion: The accuracy of heart rate measured with a wrist photoplethysmography monitor is affected by the tightness of the wristband and the phase of the signal. A high tightening is required when high accuracy is expected. [ABSTRACT FROM AUTHOR]

BACKGROUND: Thoracoabdominal asynchrony (TAA) is commonly seen in preterm infants. Respiratory inductive plethysmography (RIP) is a noninvasive way to objectively assess work of breathing (WOB) indices. The impact of bronchopulmonary dysplasia (BPD) on TAA at discharge has not been established. The aim of this study is to compare WOB indices in premature infants with a diagnosis of BPD to premature infants without a diagnosis of BPD at discharge. METHODS: A prospective, observational study of premature infants (<32 weeks gestation) at discharge during quiet breathing in the supine position. RIP noninvasively measured WOB indices. A high-resolution pulse oximeter collected oxygen saturation and heart rate data. RESULTS: This study included thirty-one infants with BPD and thirty-four infants without BPD. Infants diagnosed with BPD had increased phase angle [BPD Φ = 73. 90 (8.2) vs NoBPD Φ = 52.6 (8.2), p = 0.039]. Infants diagnosed with BPD had decreased saturations [BPD SpO2 = 96% (0.4) vs NoBPD Sp02 98% (0.3), p=<0.001], increased time with saturations less than 85% [BPD % =2.74 (0.7) vs NoBPD % =0.91 (0.4), p =.018], and increased time with saturations less than 80% [BPD % =1.57 (0.5) vs NoBPD % =0.52 (0.3), p = 0.045]. There was no difference in heart rate or breaths per minute for infants with BPD versus controls. CONCLUSION: Premature infants with BPD demonstrated increased TAA and had lower saturations compared to infants without BPD at discharge despite being chronologically older and being discharged at an older corrected gestational age. The impact of BPD on breathing patterns persists at discharge and suggests these patients may have residual lung and/or respiratory muscle dysfunction. [ABSTRACT FROM AUTHOR]

Purpose: This study assessed the cardiorespiratory capacity, anaerobic speed reserve, and anthropometric and spatiotemporal variables of a 75-year-old world-class middle-distance runner who previously obtained several European and world records in the age categories of 60–70 years, achieved 13 European titles and 15 world champion titles, and also holds several European records for the 75-year-old category. Methods: Heart rate, oxygen uptake, carbon dioxide production, ventilation, step frequency, contact time, and velocity at maximal oxygen uptake (VO2max) were measured during treadmill running. Maximal sprinting speed was assessed during track sprinting and used to compute anaerobic speed reserve. Body fat percentage was assessed using air displacement plethysmography. Results: Body fat percentage was 8.6%, VO2max was 50.5 mL·kg−1·min−1, maximal ventilation was 141 L·min−1, maximum heart rate was 164 beats·min−1, maximum respiratory exchange ratio was 1.18, and velocity at VO2max was 16.7 km·h−1. The average stride frequency and contact time during the last 30 seconds of the 4-minute run at 10 km·h−1 were 171 steps·min−1 and 241 ms and 187 steps·min−1 and 190 ms in the last 40 seconds at 17 km·h−1, respectively. The anaerobic speed reserve was 11.4 km·h−1, corresponding to an anaerobic speed reserve ratio of 1.68. Conclusion: This 75-year-old runner has an exceptionally high VO2max and anaerobic speed reserve ratio. In addition, his resilience to injuries, possibly due to a relatively high volume of easy runs, enabled him to sustain regular training since his 50s and achieve international performance in his age group. [ABSTRACT FROM AUTHOR]

Introduction: Heart rate variability biofeedback (HRVB) is awell-studied intervention known for its positive effects on emotional, cognitive, and physiological well-being, including relief from depressive symptoms. However, its practical use is hampered by high costs and a lack of trained professionals. Smartphone-based HRVB, which eliminates the need for external devices, offers a promising alternative, albeit with limited research. Additionally, premenstrual symptoms are highly prevalent among menstruating individuals, and there is a need for low-cost, accessible interventions with minimal side effects. With this pilot study, we aim to test, for the first time, the influence of smartphone-based HRVB on depressive and premenstrual symptoms, as well as anxiety/stress symptoms and attentional control. Methods: Twenty-sevenparticipantswithabove-averagepremenstrualordepressive symptoms underwent a 4-week photoplethysmography smartphone-based HRVB intervention using a waitlist-control design. Laboratory sessions were conducted before and after the intervention, spaced exactly 4 weeks apart. Assessments included resting vagally mediated heart rate variability (vmHRV), attentional control via the revised attention network test (ANT-R), depressive symptoms assessed with the BDI-II questionnaire, and stress/anxiety symptoms measured using the DASS questionnaire. Premenstrual symptomatology was recorded through the PAF questionnaire if applicable. Data analysis employed linear mixedmodels. Results: We observed improvements in premenstrual, depressive, and anxiety/stress symptoms, as well as the Executive Functioning Score of the ANT-R during the intervention period but not during the waitlist phase. However, we did not find significant changes in vmHRV or the Orienting Score of the ANT-R. Discussion: These findings are promising, both in terms of the effectiveness of smartphone-based HRVB and its potential to alleviate premenstrual symptoms. Nevertheless, to provide a solid recommendation regarding the use of HRVB for improving premenstrual symptoms, further research with a larger sample size is needed to replicate these effects. [ABSTRACT FROM AUTHOR]

Development and Calibration of a PATCH Device for Monitoring Children's Heart Rate and Acceleration. Med. Sci. Sports Exerc., Vol. 56, No. 6, pp. 1196-1207, 2024. Introduction: Current wearables that collect heart rate and acceleration were not designed for children and/or do not allow access to raw signals, making them fundamentally unverifiable. This study describes the creation and calibration of an open-source multichannel platform (PATCH) designed to measure heart rate and acceleration in children ages 3-8 yr. Methods: Children (N = 63; mean age, 6.3 yr) participated in a 45-min protocol ranging in intensities from sedentary to vigorous activity. Actiheart-5 was used as a comparison measure. We calculated mean bias, mean absolute error (MAE) mean absolute percent error (MA%E), Pearson correlations, and Lin's concordance correlation coefficient (CCC). Results: Mean bias between PATCH and Actiheart heart rate was 2.26 bpm, MAE was 6.67 bpm, and M%E was 5.99%. The correlation between PATCH and Actiheart heart rate was 0.89, and CCC was 0.88. For acceleration, mean bias was 1.16 mg and MAE was 12.24 mg. The correlation between PATCH and Actiheart was 0.96, and CCC was 0.95. Conclusions: The PATCH demonstrated clinically acceptable accuracies to measure heart rate and acceleration compared with a research-grade device. [ABSTRACT FROM AUTHOR]

OBJECTIVE To compare the accuracy of doppler ultrasound (DOP) and pulse oximeter plethysmography (POP) in the measurement of systolic arterial pressure (SAP) to invasive blood pressure (IBP) in anesthetized dogs. ANIMALS 40 client-owned healthy dogs > 10 kg. METHODS Dogs were anesthetized for surgical procedures in dorsal recumbency. Invasive blood pressure was measured from a dorsal pedal artery. DOP and POP device probes were placed over the median caudal artery with a flow-occluding cuff for noninvasive blood pressure measurement. Systolic arterial pressure measured by DOP, loss of pulse oximeter plethysmograph (POPL), and return of pulse oximeter plethysmograph (POPR) were compared to SAP measured by IBP. A linear mixed model was used to determine correlation. Bland-Altman analyses were performed to determine bias, SD, and limits of agreement. The accuracy of DOP and POP was compared to IBP across different tensive states. RESULTS Conditional R2 values for DOP, POPL, and POPR versus IBP were 0.92, 0.85, and 0.87, respectively (all P < .001). The biases for DOP, POPL, and POPR compared to IBP were +7.6 ± 13.1, +3.9 ± 14.4, and +8.6 ± 15.2 mm Hg (bias ± SD), respectively. Limits of agreement (lower, upper) were (-18.1, +33.3), (-24.3, +32.1), and (-21.2, +38.4) mm Hg for DOP, POPL, and POPR, respectively. DOP and POP overestimated SAP during hypotension (SAP < 90 mm Hg), DOP to a lesser magnitude. CLINICAL RELEVANCE DOP measured from the median caudal artery may be acceptable for SAP measurement in dorsally recumbent, healthy anesthetized dogs > 10 kg. POP was determined an unacceptable method. [ABSTRACT FROM AUTHOR]

Respiratory Inductance Plethysmography (RIP) is a non-invasive method for the measurement of respiratory rates and lung volumes. Accurate detection of respiratory rates and volumes is crucial for the diagnosis and monitoring of prognosis of lung diseases, for which spirometry is classically used in clinical applications. RIP has been studied as an alternative to spirometry and shown promising results. Moreover, RIP data can be analyzed through machine learning (ML)-based approaches for some other purposes, i.e., detection of apneas, work of breathing (WoB) measurement, and recognition of human activity based on breathing patterns. The goal of this study is to provide an in-depth systematic review of the scope of usage of RIP and current RIP device developments, as well as to evaluate the performance, usability, and reliability of ML-based data analysis techniques within its designated scope while adhering to the PRISMA guidelines. This work also identifies research gaps in the field and highlights the potential scope for future work. The IEEE Explore, Springer, PLoS One, Science Direct, and Google Scholar databases were examined, and 40 publications were included in this work through a structured screening and quality assessment procedure. Studies with conclusive experimentation on RIP published between 2012 and 2023 were included, while unvalidated studies were excluded. The findings indicate that RIP is an effective method to a certain extent for testing and monitoring respiratory functions, though its accuracy is lacking in some settings. However, RIP possesses some advantages over spirometry due to its non-invasive nature and functionality for both stationary and ambulatory uses. RIP also demonstrates its capabilities in ML-based applications, such as detection of breathing asynchrony, classification of apnea, identification of sleep stage, and human activity recognition (HAR). It is our conclusion that, though RIP is not yet ready to replace spirometry and other established methods, it can provide crucial insights into subjects' condition associated to respiratory illnesses. The implementation of artificial intelligence (AI) could play a potential role in improving the overall effectiveness of RIP, as suggested in some of the selected studies. [ABSTRACT FROM AUTHOR]

The thoracoabdominal breathing motion pattern is being considered in sports training because of its contribution, along with other physiological adaptations, to overall performance. We examined whether and how experience with cycling training modifies the thoracoabdominal motion patterns. We utilized optoelectronic plethysmography to monitor ten trained male cyclists and compared them to ten physically active male participants performing breathing maneuvers. Cyclists then participated in a self-paced time trial to explore the similarity between that observed during resting breathing. From the 3D coordinates of 32 markers positioned on each participant's trunk, we calculated the percentage of contribution of the superior thorax, inferior thorax, and abdomen and the correlation coefficient among these compartments. During the rest maneuvers, the cyclists showed a thoracoabdominal motion pattern characterized by an increased role of the inferior thorax relative to the superior thorax (26.69 ± 5.88%, 34.93 ± 5.03%; p= 0.002, respectively), in contrast to the control group (26.69 ± 5.88%; 25.71 ± 6.04%, p= 0.4, respectively). In addition, the inferior thorax showed higher coordination in phase with the abdomen. Furthermore, the results of the time trial test underscored the same pattern found in cyclists breathing at rest, suggesting that the development of a permanent modification in respiratory mechanics may be associated with cycling practice. [ABSTRACT FROM AUTHOR]

Objectives: This study investigates the chest wall motions and estimates respiratory volumes in a patient with scoliosis compared to a healthy person using the optoelectronic plethysmography method in a sitting position. Methods: In this research, a scoliosis patient and a healthy individual comprised two subjects. Each person's upper, middle, and lower chest movement in a seated position was measured using optoelectronic plethysmography. Results: The changes in respiratory volumes of the middle and lower parts of the chest in patients with scoliosis are more than those of a healthy person during quiet breathing. Moreover, the changes in the upper, middle, and lower parts of the chest in the healthy person are also more than those of the subject with scoliosis during deep breathing. Discussion: Optoelectronic plethysmography is a noninvasive method to evaluate chest wall movements, respiratory system function, and volumes with fewer limitations than other methods of evaluating respiratory function. [ABSTRACT FROM AUTHOR]

Aims/hypothesis: The aim of this substudy (Eudra CT No:2019-001997-27)was to assess ATB availability in patients with infected diabetic foot ulcers(IDFUs)in the context of microcirculation and macrocirculation status. Methods: For this substudy, we enrolled 23 patients with IDFU. Patients were treated with boluses of amoxicillin/clavulanic acid(AMC)(12patients) or ceftazidime(CTZ)(11patients). After induction of a steady ATB state, microdialysis was performed near the IDFU. Tissue fluid samples from the foot and blood samples from peripheral blood were taken within 6 hours. ATB potential efficacy was assessed by evaluating the maximum serum and tissue ATB concentrations(Cmax and Cmax-tissue)and the percentage of time the unbound drug tissue concentration exceeds the minimum inhibitory concentration (MIC)(=100% tissue and =50%/60% tissue fT>MIC). Vascular status was assessed by triplex ultrasound, ankle-brachial and toe-brachial index tests, occlusive plethysmography comprising two arterial flow phases, and transcutaneous oxygen pressure(TcPO2). Results: Following bolus administration, the Cmax of AMC was 91.8 ± 52.5 mgmL-1 and the Cmax-tissue of AMC was 7.25 ± 4.5 mgmL-1(P<0.001). The Cmax for CTZ was 186.8 ± 44.1 mgmL-1 and the Cmax-tissue of CTZ was 18.6 ± 7.4 mgmL-1(P<0.0001). Additionally, 67% of patients treated with AMC and 55% of those treated with CTZ achieved tissue fT>MIC levels exceeding 50% and 60%, respectively. We observed positive correlations between both Cmax-tissue and AUCtissue and arterial flow. Specifically, the correlation coefficient for the first phase was r=0.42; (P=0.045), and for the second phase, it was r=0.55(P=0.01)and r=0.5(P=0.021). Conclusions: Bactericidal activity proved satisfactory in only half to two-thirds of patients with IDFUs, an outcome that appears to correlate primarily with arterial flow. [ABSTRACT FROM AUTHOR]

This study aimed to propose a portable and intelligent rehabilitation evaluation system for digital stroke-patient rehabilitation assessment. Specifically, the study designed and developed a fusion device capable of emitting red, green, and infrared lights simultaneously for photoplethysmography (PPG) acquisition. Leveraging the different penetration depths and tissue reflection characteristics of these light wavelengths, the device can provide richer and more comprehensive physiological information. Furthermore, a Multi-Channel Convolutional Neural Network–Long Short-Term Memory–Attention (MCNN-LSTM-Attention) evaluation model was developed. This model, constructed based on multiple convolutional channels, facilitates the feature extraction and fusion of collected multi-modality data. Additionally, it incorporated an attention mechanism module capable of dynamically adjusting the importance weights of input information, thereby enhancing the accuracy of rehabilitation assessment. To validate the effectiveness of the proposed system, sixteen volunteers were recruited for clinical data collection and validation, comprising eight stroke patients and eight healthy subjects. Experimental results demonstrated the system's promising performance metrics (accuracy: 0.9125, precision: 0.8980, recall: 0.8970, F1 score: 0.8949, and loss function: 0.1261). This rehabilitation evaluation system holds the potential for stroke diagnosis and identification, laying a solid foundation for wearable-based stroke risk assessment and stroke rehabilitation assistance. [ABSTRACT FROM AUTHOR]

Background: Cats in respiratory distress have limited tolerance for manipulation, hindering clinical monitoring. Minute volume (MV) can be utilized to rate dyspnea in humans, but its relationship with respiratory distress in cats remains poorly investigated. Hypothesi s : Cats with respiratory distress will show higher MV per kg body weight (MV/BW) than normal cats, and the MV/BW increase will correlate with survival. Animals: Fifty‐two cats with respiratory distress from lung parenchymal disease, pleural space disease, lower airway obstruction (LAO), or upper airway obstruction were recruited since 2014. Methods: This is a prospective observational study. Study cats were placed in a transparent chamber, allowing clinicians to easily observe their breathing status and record ventilation using barometric whole‐body plethysmography (BWBP). Ventilatory variables of the 52 cats were compared with those of 14 historic control cats. Follow‐up data, including disease category, clinical outcomes, and survival, were prospectively collected. Results: Cats in respiratory distress demonstrated significantly higher MV/BW (397 mL/kg; range, 158‐1240) than normal cats (269 mL/kg; range, 168‐389; P <.001). Among the etiologies, cats with LAO, parenchymal, and pleural space disease exhibited higher‐than‐normal MV/BW trends. A cutoff value of 373 mL/kg (1.4‐fold increase) indicated abnormally increased breathing efforts (sensitivity, 67%; specificity, 93%). MV/BW was independently associated with increased cardiorespiratory mortality in cats with respiratory distress (adjusted hazard ratio 1.17, 95% confidence interval [CI] 1.02‐1.35; P =.03). Conclusions and Clinical Importance: Breathing efforts in cats can be noninvasively quantified using BWBP. Measurement of MV/BW could serve as a prognostic index for monitoring cats experiencing respiratory distress. [ABSTRACT FROM AUTHOR]

To determine the validity of bioelectrical impedance analysis (BIA) in quantifying fat-free mass (FFM) compared to air-displacement plethysmography (ADP) in patients with a motor neurone disease (MND). FFM of 140 patients diagnosed with MND was determined by ADP using the BodPod (i.e. the gold standard), and by BIA using the whole-body Bodystat. FFM values were translated to predicted resting energy expenditure (REE); the actual REE was measured using indirect calorimetry, resulting in a metabolic index. Validity of the BIA compared to the ADP was assessed using Bland-Altman analysis and Pearson's r. To assess the clinical relevance of differences, we evaluated changes in metabolic index and in individualized protein demand. Despite the high correlation between ADP and BIA (r = 0.93), averaged across patients, the assessed mean fat-free mass was 51.7 kg (± 0.9) using ADP and 54.2 kg (± 1.0) using BIA. Hence, BIA overestimated fat-free mass by 2.5 kg (95% CI 1.8–3.2, p < 0.001). Clinically, an increased metabolic index would be more often underdiagnosed in patients with MND using BIA (31.4% according to BIA versus 44.2% according to ADP, p = 0.048). A clinically relevant overestimation of ≥ 15 g in protein demand was observed for 4 (2.9%) patients using BIA. BIA systematically overestimates FFM in patients with MND. Although the differences are limited with ADP, underscoring the utility of BIA for research, overestimation of fat-free mass may have consequences for clinical decision-making, especially when interest lies in determining the metabolic index. [ABSTRACT FROM AUTHOR]

Repetitive tasks can lead to long-term cardiovascular problems due to continuous strain and inadequate recovery. The automobile operators on the assembly line are exposed to these risks when workload volume changes according to the workstation type. However, the current ergonomic assessments focus primarily on observational and, in some cases, biomechanical methods that are subjective and time-consuming, overlooking cardiorespiratory adaptations. This study aimed to analyze the cardiorespiratory response to distinct workload volumes and ergonomic risk (ER) scores for an automotive assembly line. Sixteen male operators (age = 38 ± 8 years; BMI = 25 ± 3 kg·m2) volunteered from three workstations (H1, H2, and H3) with specific work cycle duration (1, 3, and 5 min respectively). Electrocardiogram (ECG), respiratory inductance plethysmography (RIP), and accelerometer (ACC) data were collected during their shift. The results showed significant differences from the first to the last 10 min, where H3 had its SDRRi reduced (p = 0.014), H1's phase synchrony and H2's coordination between thoracic and abdominal movements decreased (p < 0.001, p = 0.039). In terms of ergonomic risk, the moderate-high rank showed a reduction in SDRRi (p = 0.037) and moderate-risk activities had diminished phase synchrony (p = 0.018) and correlation (p = 0.004). Thus, the explored parameters could have the potential to develop personalized workplace adaptation and risk assessment systems. [ABSTRACT FROM AUTHOR]

Dysfunctional breathing (DB) describes a respiratory condition that is mainly characterized by abnormal breathing patterns, affecting both children and adults, often leading to intermittent or chronic complaints and influencing physiological, psychological, and social aspects. Some symptoms include breathlessness; dizziness; palpitations; and anxiety, while its classification lies in breathing pattern disorders and upper airway involvement. Its prevalence among the pediatric population varies with a female overrepresentation, while the existence of comorbidities in DB, such as asthma, gastro-esophageal reflux, nasal diseases, and anxiety/depression, frequently leads to misdiagnosis or underdiagnosis and complicates therapeutic approaches. The basic diagnostic tools involve a detailed history, physical examination, and procedures such as structured light plethysmography, cardiopulmonary exercise testing, and laryngoscopy when a laryngeal obstruction is present. The management of DB presumes a multidimensional approach encompassing breathing retraining, disease-specific advice through speech and language therapy in the presence of laryngeal obstruction, psychotherapy for fostering self-efficacy, and surgical therapy in a structural abnormality. The current review was developed to provide a summary of classifications of DB and epidemiological data concerning the pediatric population, comorbidities, diagnostic tools, and therapeutic approaches to enhance the comprehension and management of DB in children. [ABSTRACT FROM AUTHOR]

Featured Application: Near-infrared spectroscopy (NIRS) has gained popularity in biomedical and sport sciences to non-invasively assess the microvascular responses and health in men and women. Venous occlusion plethysmography (VOP) is also capable of assessing microvascular health. However, due to the ease of assessment and portability of a NIRS sensor, this method may be more favorable to some individuals. Currently, there are limited direct comparisons between each approach, and thus, the ability to interchange values is not clear. Here, it was reported that NIRS responses do not correlate well with strain-gauge VOP values. Background: Venous occlusion plethysmography (VOP) non-invasively measures forearm blood flow (FBF), whereas near-infrared spectroscopy (NIRS) assesses skeletal muscle oxygenation. Using these techniques has revealed sex differences in microvascular responses. However, it is not clear if NIRS and VOP results are interchangeable under various conditions like reactive hyperemia (RH). Our purpose was to evaluate sex-specific associations between FBF and NIRS-derived parameters: oxygenated hemoglobin, deoxygenated hemoglobin, total hemoglobin, and hemoglobin difference (O2Hb, HHb, tHb, and HbDiff). Methods: In total, 29 adults (15 men) participated, and a strain-gauge was placed on the forearm for VOP and a NIRS device was distally attached. Slopes for FBF and NIRS parameters were quantified during venous occlusion intervals at rest and during RH. Pearson's correlations were assessed between VOP and NIRS slopes. Intraclass correlation coefficients (ICC2,1) examined the sex-specific consistency of the slopes at rest. p ≤ 0.05 was considered significant. Results: During RH, FBF was not correlated with O2Hb (r = −0.126), HHb (r = 0.228), tHb (r = 0.061), or HbDiff (r = 0.046). Seemingly, there were no sex differences. Resting FBF and NIRS-derived variables, except for HbDiff, displayed suitable consistency as suggested by the reliability results (ICC2,1 = 0.115–0.577). Conclusions: The NIRS values collected did not match the strain-gauge slopes. Individuals should practice caution when generating blood flow inferences from NIRS-based data during VOP. [ABSTRACT FROM AUTHOR]

Background: Reference values for lung volumes are necessary to identify and diagnose restrictive lung diseases and hyperinflation, but the values have to be validated in the relevant population. Our aim was to investigate the Global Lung Function Initiative (GLI) reference equations in a representative healthy Austrian population and create population-derived reference equations if poor fit was observed. Methods: We analysed spirometry and body plethysmography data from 5371 respiratory healthy subjects (6–80 years) from the Austrian LEAD Study. Fit with the GLI equations was examined using z-scores and distributions within the limits of normality. LEAD reference equations were then created using the LMS method and the generalized additive model of location shape and scale package according to GLI models. Results: Good fit, defined as mean z-scores between + 0.5 and -0.5,was not observed for the GLI static lung volume equations, with mean z-scores > 0.5 for residual volume (RV), RV/TLC (total lung capacity) and TLC in both sexes, and for expiratory reserve volume (ERV) and inspiratory capacity in females. Distribution within the limits of normality were shifted to the upper limit except for ERV. Population-derived reference equations from the LEAD cohort showed superior fit for lung volumes and provided reproducible results. Conclusion: GLI lung volume reference equations demonstrated a poor fit for our cohort, especially in females. Therefore a new set of Austrian reference equations for static lung volumes was developed, that can be applied to both children and adults (6–80 years of age). [ABSTRACT FROM AUTHOR]

Background. Accurate measurements of limb volumes are important for clinical reasons. We aimed to assess the reliability and validity of two centimetric and two optoelectronic techniques for limb volume measurements against water volumetry, defined as the gold standard. Methods. Five different measurement methods were executed on the same day for each participant, namely water displacement, fixed-height (circumferences measured every 5 (10) cm for the upper (lower limb) centimetric technique, segmental centimetric technique (circumferences measured according to proportional height), optoelectronic plethysmography (OEP, based on a motion analysis system), and IGOODI Gate body scanner technology (which creates an accurate 3D avatar). Results. A population of 22 (15 lower limbs, 11 upper limbs, 8 unilateral upper limb lymphoedema, and 6 unilateral lower limb lymphoedema) participants was selected. Compared to water displacement, the fixed-height centimetric method, the segmental centimetric method, the OEP, and the IGOODI technique resulted in mean errors of 1.2, 0.86, −16.0, and 0.71%, respectively. The corresponding slopes (and regression coefficients) of the linear regression lines were 1.0002 (0.98), 1.0047 (0.99), 0.874 (0.94) and 0.9966 (0.99). Conclusion. The centimetric methods and the IGOODI system are accurate in measuring limb volume with an error of <2%. It is important to evaluate new objective and reliable techniques to improve diagnostic and follow-up possibilities. [ABSTRACT FROM AUTHOR]

Introduction: Advanced chronic obstructive pulmonary disease (COPD) is associated with chronic hypercapnic failure. The present work aimed to comprehensively investigate inspiratory muscle function as a potential key determinant of hypercapnic respiratory failure in patients with COPD. Methods: Prospective patient recruitment encompassed 61 stable subjects with COPD across different stages of respiratory failure, ranging from normocapnia to isolated nighttime hypercapnia and daytime hypercapnia. Arterialized blood gas analyses and overnight transcutaneous capnometry were used for patient stratification. Assessment of respiratory muscle function encompassed body plethysmography, maximum inspiratory pressure (MIP), diaphragm ultrasound, and transdiaphragmatic pressure recordings following cervical magnetic stimulation of the phrenic nerves (twPdi) and a maximum sniff manoeuvre (Sniff Pdi). Results: Twenty patients showed no hypercapnia, 10 had isolated nocturnal hypercapnia, and 31 had daytime hypercapnia. Body plethysmography clearly distinguished patients with and without hypercapnia but did not discriminate patients with isolated nocturnal hypercapnia from those with daytime hypercapnia. In contrast to ultrasound parameters and transdiaphragmatic pressures, only MIP reflected the extent of hypercapnia across all three stages. MIP values below −48 cmH2O predicted nocturnal hypercapnia (area under the curve = 0.733, p = 0.052). Conclusion: In COPD, inspiratory muscle dysfunction contributes to progressive hypercapnic failure. In contrast to invasive tests of diaphragm strength only MIP fully reflects the pathophysiological continuum of hypercapnic failure and predicts isolated nocturnal hypercapnia. [ABSTRACT FROM AUTHOR]

Background: Wearable devices based on the PPG algorithm can detect atrial fibrillation (AF) effectively. However, further investigation of its application on long‐term, continuous monitoring of AF burden is warranted. Method: The performance of a smartwatch with continuous photoplethysmography (PPG) and PPG‐based algorithms for AF burden estimation was evaluated in a prospective study enrolling AF patients admitted to Beijing Anzhen Hospital for catheter ablation from September to November 2022. A continuous Electrocardiograph patch (ECG) was used as the reference device to validate algorithm performance for AF detection in 30‐s intervals. Results: A total of 578669 non‐overlapping 30‐s intervals for PPG and ECG each from 245 eligible patients were generated. An interval‐level sensitivity of PPG was 96.3% (95% CI 96.2%–96.4%), and specificity was 99.5% (95% CI 99.5%–99.6%) for the estimation of AF burden. AF burden estimation by PPG was highly correlated with AF burden calculated by ECG via Pearson correlation coefficient (R2 = 0.996) with a mean difference of ‐0.59 (95% limits of agreement, ‐7.9% to 6.7%). The subgroup study showed the robust performance of the algorithm in different subgroups, including heart rate and different hours of the day. Conclusion: Our results showed the smartwatch with an algorithm‐based PPG monitor has good accuracy and stability in continuously monitoring AF burden compared with ECG patch monitors, indicating its potential for diagnosing and managing AF. [ABSTRACT FROM AUTHOR]

Fentanyl exposure and overdose are growing concerns in public health and occupational safety. This study aimed to establish parameters of fentanyl lethality in SKH1 mice for future overdose research. Lethality was determined using the up‐down procedure, with subjects monitored post‐administration using pulse oximetry (5 min) and then whole‐body plethysmography (40 min). Following the determination of subcutaneous dose–response, [18F]Fluorodeoxyglucose positron emission tomography (18F‐FDG PET) was performed after LD10 fentanyl at 40 min, 6 h, 24 h or 7 days post‐dose. LD10 and LD50 were observed to be 110 and 135 mg/kg, respectively, and consistent with four‐parameter logistic fit values of 111.2 and 134.6 mg/kg (r2 = 0.9996). Overdose (LD10 or greater) yielded three distinct cardiovascular groups: survival, non‐survival with blood oxygen saturation (SpO2) minimum ≥37% and non‐survival with SpO2 <37%. Breaths per minute, minute volume and inspiratory quotient were significantly different between surviving and non‐surviving animals for up to 40 min post‐injection. 18F‐FDG PET revealed decreased glucose uptake in the heart, lungs and brain for up to 24 h. These findings provide critical insights into fentanyl lethality in SKH1 mice, including non‐invasive respiratory effects and organ‐specific impacts that are invaluable for future translational studies investigating the temporal effects of fentanyl overdose. Fentanyl exposure and overdose are growing concerns in public health and occupational safety. This study aimed to establish parameters of fentanyl lethality in SKH1 mice for future overdose research. After a single subcutaneous injection of fentanyl, subjects were monitored via pulse oximetry for 5 min, respiration for 40 min, then imaged for glucose uptake using positron emission tomography (PET). Pulse oximetry revealed a cardiac phenomenon determining acute lethality, respiratory data exhibited significant differences associated with survival, and PET showed decreased glucose uptake for up to 24 h. These non‐invasive, organ‐specific findings are critical for future temporal studies on fentanyl overdose. [ABSTRACT FROM AUTHOR]

Objective: The current study aimed to investigate the relationship between resiliency and the prevalence and severity of prenatal anxiety and depression in the context of high-risk pregnancies. Methods: A descriptive cross-sectional correlational survey design was used. A convenience sample of 404 high-risk pregnant women from a maternity department at the National Guard Health Affairs hospital, in Jeddah completed three online scales: the Connor-Davidson Resilience Scale, the Patient Health Questionnaire-9, and the Generalized Anxiety Disorder-7. Results: Most women (89.85%) had low resilience, while only 1.98% had high resilience. There was a strong negative correlation between resilience and depression (r = -0.81, p < 0.001) and between resilience and anxiety (r = -0.79, p < 0.001). Women with low resilience had higher levels of depression and anxiety than women with high resilience. Additionally, women with high-risk pregnancies who have higher levels of resilience are more likely to have normal vaginal delivery, to be employed, and to have fewer pregnancy complications than those who have lower levels of resilience Conclusion: Resilience is an important factor for the mental health of women with high-risk pregnancies. Interventions to enhance resilience may help reduce the psychological burden of high-risk pregnancies and improve maternal and fetal outcomes. Further research is needed to explore the causal mechanisms and the modifiable factors that influence resilience. [ABSTRACT FROM AUTHOR]

Apnea detection is critical to the management of infant apnea. Effective monitoring and management of apnea using apnea monitors is known to reduce complications and possible fatalities in infants. There is a need to determine the critical design considerations in apnea monitors. This article reviews the design and development of infant apnea monitors. We conducted a targeted literature review from different databases, including PubMed, ScienceDirect, and Google Scholar. We reviewed articles published between January 1995 and February 2023. The search was done using combinations of key terms, namely, “apnea,” “apnea monitors,” and “apnea monitor design.” Articles that met the inclusion criteria were extracted and analyzed. The review investigated common physiological parameters, sensor types, and validation results of apnea monitors. The review revealed important design considerations adopted in the literature as well as the different sensor types and methods of apnea detection. It was found that thoracic impedance pneumography, thermistors, respiratory inductance plethysmography, pneumotachograph, and MEMS accelerometer are the most common sensor types used to design apnea monitors. The review revealed that most apnea monitors were designed to measure multiple physiological parameters. Device validation results varied from one device to another, with sensitivity and specificity metrics ranging between 80% and 96%. With the high burden of infant apnea in developing countries and its associated mortality and morbidity, the design of functional infant apnea monitors has become increasingly important to complement the expensive and complex polysomnography technique. Therefore, we must use appropriate sensors and design approaches for effective detection of infant apnea. [ABSTRACT FROM AUTHOR]

Background: The effect of position and gender on chest movements and respiratory volumes is controversial and investigated in only a few studies.Objective: This study aimed to investigate the effects of position and gender on the breathing pattern during four different positions in healthy individuals.Material and Methods: In this cross-sectional study, twenty-eight (14 males, 14 females) healthy individuals participated aged 20-45 years. The optoelectronic plethysmography (OEP) method was used for the three-dimensional evaluation of chest wall motions and the compartmental analysis of the breathing pattern in supine, sitting, standing, and active straight leg raised (ASLR) positions. Volume changes in different parts of the chest wall were also measured.Results: Position affected total and compartmental respiratory volumes in both genders. Respiratory volumes decreased in the supine position compared to sitting and standing. Total and abdominal respiratory volumes also decreased in females when comparing supine positions with the ASLR. A higher pulmonary rib cage contribution was identified in females, and males exhibited higher abdominal rib cage volume compared with females. Conclusion: The breathing pattern was affected by position and gender, and the respiratory volumes increased in more upright positions, perhaps due to a greater gravitational load. The ASLR decreases the respiratory volume, which is probably due to increased postural demand.

Sleep is crucial for physical and mental health, but traditional sleep quality assessment methods have limitations. This scoping review analyzes 35 articles from the past decade, evaluating 62 wearable setups with varying sensors, algorithms, and features. Our analysis indicates a trend towards combining accelerometer and photoplethysmography (PPG) data for out-of-lab sleep staging. Devices using only accelerometer data are effective for sleep/wake detection but fall short in identifying multiple sleep stages, unlike those incorporating PPG signals. To enhance the reliability of sleep staging wearables, we propose five recommendations: (1) Algorithm validation with equity, diversity, and inclusion considerations, (2) Comparative performance analysis of commercial algorithms across multiple sleep stages, (3) Exploration of feature impacts on algorithm accuracy, (4) Consistent reporting of performance metrics for objective reliability assessment, and (5) Encouragement of open-source classifier and data availability. Implementing these recommendations can improve the accuracy and reliability of sleep staging algorithms in wearables, solidifying their value in research and clinical settings. [ABSTRACT FROM AUTHOR]

Background: With the rise of smartphone ownership and increasing evidence to support the suitability of smartphone usage in healthcare, the light source and smartphone camera could be utilized to perform photoplethysmography (PPG) for the assessment of vital signs, such as heart rate (HR). However, until rigorous validity assessment has been conducted, PPG will have limited use in clinical settings. Objective: We aimed to conduct a scoping review assessing the validity of resting heart rate (RHR) acquisition from PPG utilizing contact-based smartphone devices. Our four specific objectives of this scoping review were to (1) conduct a systematic search of the published literature concerning contact-based smartphone device-derived PPG, (2) map study characteristics and methodologies, (3) identify if methodological and technological advancements have been made, and (4) provide recommendations for the advancement of the investigative area. Methods: ScienceDirect, PubMed and SPORTDiscus were searched for relevant studies between January 1st, 2007, and November 6th, 2022. Filters were applied to ensure only literature written in English were included. Reference lists of included studies were manually searched for additional eligible studies. Results: In total 10 articles were included. Articles varied in terms of methodology including study characteristics, index measurement characteristics, criterion measurement characteristics, and experimental procedure. Additionally, there were variations in reporting details including primary outcome measure and measure of validity. However, all studies reached the same conclusion, with agreement ranging between good to very strong and correlations ranging from r = .98 to 1. Conclusions: Smartphone applications measuring RHR derived from contactbased smartphone PPG appear to agree with gold standard electrocardiography (ECG) in healthy subjects. However, agreement was established under highly controlled conditions. Future research could investigate their validity and consider effective approaches that transfer these methods from laboratory conditions into the "real-world", in both healthy and clinical populations. [ABSTRACT FROM AUTHOR]

Background: Pulmonary function testing by barometric whole-body plethysmography (BWBP) is a long-established and well-accepted, non-invasive investigative procedure in cats. Hypothesis/Objectives: To evaluate, if different acclimatization times influence the measurement parameters of BWBP in healthy adult cats. Animals: 48 healthy adult cats. Methods: In the prospective observational study, healthy cats were placed in a measuring chamber and BWBP was performed over 30 minutes. Parameters obtained during the three measurement units of 10 minutes each (T1, T2 and T3) were compared. Results: All measurement parameters except for tidal volume per body weight changed significantly (p<0.05) over the three time periods. From T1-T2, the parameters minute volume per body weight (p<0.001), peak inspiratory flow per body weight (p<0.001), peak expiratory flow per body weight (p = 0.002), pause (p = 0.03), enhanced pause (p = 0.03) and quotient of peak expiratory flow divided by expiratory flow at end expiratory volume plus 50% tidal volume (p = 0.03) changed significantly. From the time interval T2-T3, only respiratory rate (p = 0.02), inspiratory time (p = 0.02), expiratory time (p = 0.04), and relaxation time (p = 0.01) changed significantly. All measurement parameters except for tidal volume per body weight changed significantly (p<0.05) between T1 and T3. Age had a significant influence on all parameters except for peak expiratory flow per body weight and peak inspiratory flow per body weight. The parameters were not influenced by sex. Conclusion and clinical importance: All measurement parameters except tidal volume per body weight were significantly affected by acclimatization time. Controlling for age and sex, there was still a significant influence of acclimatization time on all parameters except for tidal volume per body weight. Standardization of the acclimatization time for future studies would be appropriate in order to maintain comparability. [ABSTRACT FROM AUTHOR]