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Background: Free throws serve as a crucial scoring mechanism in basketball games. As the level of basketball and the intensity of competition continue to improve, the frequency of free throw attempts gradually rises. However, with heightened game intensity, maintaining a consistent free throw success rate becomes increasingly challenging. The aim of this study was to investigate the eye movement characteristics exhibited by basketball players during free throws of varying intensities, as well as explore the relationship between these eye movement characteristics and free throw percentage. Methods: Twenty elite female basketball players were recruited to perform free throws at varying exercise intensities (low, moderate, and high) while wearing an eye tracker device. Eye tracking data was collected using the Tobii Glasses 3 eye tracker. Additionally, the Polar team pro, a heart rate monitoring system manufactured in Finland, was utilized to monitor participants' heart rates during different exercise intensities. Results: The average number of fixations on the hoop and net during free throws of varying intensities exhibited statistically significant differences (P < 0.05). The fixation durations of the hoop, backboard, and net exhibited statistically significant differences (P < 0.05). Notably, the hoop accounted for the highest proportion of the overall average fixation duration. high-intensity free throws necessitate lengthier processing durations compared to low-intensity and medium-intensity free throws. Furthermore, for free throws of moderate intensity, there was a significant negative correlation between the number of fixations on the hoop and free throw percentage (P < 0.05). Conversely, for high intensity free throws, there was a significant positive correlation between the fixation duration on the hoop and free throw percentage (P < 0.05). Conclusions: Under the three kinds of sports intensity, the players mainly focus on the hoop position, the moderate intensity free throw has the best stability, and the information search strategy and information processing efficiency are the highest. In high intensity free throws, the longer the fixation duration at the hoop, the higher the free throw percentage; The higher the number of fixations at the hoop, the lower the percentage of free throws. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine: (1) whether physically active virtual reality (VR) games exert an acute hypoaglesic effect on the thigh and bicep compared to a non-active VR game and an exercise only condition matched for exercise intensity in healthy individuals, and (2) whether movement variables during gameplay are associated with the hypoalgesic effect of the games. Twenty young adults completed five separate study sessions, with each session devoted to playing one head-mounted display VR game or stationary cycling for 15 minutes. The games included Holopoint at level 2 and level 3, Hot Squat, and Relax Walk. Pressure pain thresholds at the thigh and bicep were measured pre and post VR gameplay and cycling. Participants wore a heart rate monitor and accelerometers on the wrist and thigh during play to measure the intensity and quantity of movement. Repeated measures ANOVAs revealed that pressure pain thresholds on the bicep increased from pre to posttest for each condition. The results also revealed that pressure pain thresholds on the thigh increased only for the conditions eliciting the greatest cardiovascular response, which included Holopoint at level 3, Hot Squat, and cycling. Bivariate correlations indicated that moderate to vigorous physical activity of the thigh was associated with pain reduction at the thigh during Holopoint. These results revealed that active VR games and exercise exerted a more widespread hypoalgesic effect compared to the non-active VR game, which was likely driven in part by the intensity and quantity of movement during gameplay. [ABSTRACT FROM AUTHOR]

Background: Heart rate variability (HRV), an important marker of autonomic nervous system activity, is usually determined from electrocardiogram (ECG) recordings corrected for extrasystoles and artifacts. Especially in large population-based studies, computer-based algorithms are used to determine RR intervals. The Modular ECG Analysis System MEANS is a widely used tool, especially in large studies. The aim of this study was therefore to evaluate MEANS for its ability to detect non-sinus ECG beats and artifacts and to compare HRV parameters in relation to ECG processing. Additionally, we analyzed how ECG processing affects the statistical association of HRV with cardiovascular disease (CVD) risk factors. Methods: 20-min ECGs from 1,674 subjects of the population-based CARLA study were available for HRV analysis. All ECGs were processed with the ECG computer program MEANS. A reference standard was established by experienced clinicians who visually inspected the MEANS-processed ECGs and reclassified beats if necessary. HRV parameters were calculated for 5-minute segments selected from the original 20-minute ECG. The effects of misclassified typified normal beats on i) HRV calculation and ii) the associations of CVD risk factors (sex, age, diabetes, myocardial infarction) with HRV were modeled using linear regression. Results: Compared to the reference standard, MEANS correctly classified 99% of all beats. The averaged sensitivity of MEANS across all ECGs to detect non-sinus beats was 76% [95% CI: 74.1;78.5], but for supraventricular extrasystoles detection sensitivity dropped to 38% [95% CI: 36.8;38.5]. Time-domain parameters were less affected by false sinus beats than frequency parameters. Compared to the reference standard, MEANS resulted in a higher SDNN on average (mean absolute difference 1.4ms [95% CI: 1.0;1.7], relative 4.9%). Other HRV parameters were also overestimated as well (between 6.5 and 29%). The effect estimates for the association of CVD risk factors with HRV did not differ between the editing methods. Conclusion: We have shown that the use of the automated MEANS algorithm may lead to an overestimation of HRV due to the misclassification of non-sinus beats, especially in frequency domain parameters. However, in population-based studies, this has no effect on the observed associations of HRV with risk factors, and therefore an automated ECG analyzing algorithm as MEANS can be recommended here for the determination of HRV parameters. [ABSTRACT FROM AUTHOR]

The pervasive use of social media has raised concerns about its potential detrimental effects on physical and mental health. Others have demonstrated a relationship between social media use and anxiety, depression, and psychosocial stress. In light of these studies, we examined physiological indicators of stress (heart rate to measure autonomic nervous system activation and cortisol to assess activity of the hypothalamic-pituitary-adrenal axis) associated with social media use and investigated possible moderating influences of sex, age, and psychological parameters. We collected physiological data from 59 subjects ranging in age from 13 to 55 across two cell phone treatments: social media use and a pre-selected YouTube playlist. Heart rate was measured using arm-band heart rate monitors before and during cell phone treatments, and saliva was collected for later cortisol analysis (by enzyme immunoassay) before and after each of the two cell phone treatments. To disentangle the effects of cell phone treatment from order of treatment, we used a crossover design in which participants were randomized to treatment order. Our study uncovered a significant period effect suggesting that both heart rate and cortisol decreased over the duration of our experiment, irrespective of the type of cell phone activity or the order of treatments. There was no indication that age, sex, habits of social media use, or psychometric parameters moderated the physiological response to cell phone activities. Our data suggest that 20-minute bouts of social media use or YouTube viewing do not elicit a physiological stress response. [ABSTRACT FROM AUTHOR]

This study presents a novel concept for a smart home cage design, tools, and software used to monitor the physiological parameters of mice and rats in animal-based experiments. The proposed system focuses on monitoring key clinical parameters, including heart rate, respiratory rate, and body temperature, and can also assess activity and circadian rhythm. As the basis of the smart home cage system, an in-depth analysis of the requirements was performed, including camera positioning, imaging system types, resolution, frame rates, external illumination, video acquisition, data storage, and synchronization. Two different camera perspectives were considered, and specific camera models, including two near-infrared and two thermal cameras, were selected to meet the requirements. The developed specifications, hardware models, and software are freely available via GitHub. During the first testing phase, the system demonstrated the potential of extracting vital parameters such as respiratory and heart rate. This technology has the potential to reduce the need for implantable sensors while providing reliable and accurate physiological data, leading to refinement and improvement in laboratory animal care. [ABSTRACT FROM AUTHOR]

Background: Cardiac rehabilitation (CR) is an evidence-based comprehensive program that includes exercise training, health education, physical activity promotion, and extensive counseling for the management of cardiovascular risk factors. Wearable devices monitor certain physiological functions, providing biometric data such as heart rate, movement, sleep, ECG analysis, blood pressure, energy expenditure, and numerous other parameters. Recent evidence supports wearable devices as a likely relevant component in cardiovascular risk assessment and disease prevention. The purpose of this scoping review is to better understand the role of wearable devices in home-based CR (HBCR) and to characterize the evidence regarding the incorporation of wearable devices in HBCR programs and cardiovascular outcomes. Methods & findings: We created a search strategy for multiple databases, including PubMed, Embase (Elsevier), CINAHL (Ebsco), Cochrane CENTRAL (Wiley), and Scopus (Elsevier). Studies were included if the patients were eligible for CR per Medicare guidelines and >18 years of age and if some type of wearable device was utilized during HBCR. Our search yielded 57 studies meeting all criteria. The studies were classified into 4 groups: patients with coronary heart disease (CHD) without heart failure (HF); patients with HF; patients with heart valve repair or replacement; and patients with exposure to center-based CR. In three groups, there was an upward trend toward improvement in quality of life (QOL) and peak VO2, less sedentary time, and an increase in daily step count in the intervention groups compared to control groups. Conclusions: HBCR using wearable devices can be a comparable alternative or adjunct to center-based CR for patients with CHD and HF. More studies are needed to draw conclusions about the comparability of HBCR to center-based CR in patients with heart valve repair or replacement. [ABSTRACT FROM AUTHOR]

There is a growing body of literature demonstrating that a single bout of exercise benefits executive cognitive function. While the acute effect of closed-skill exercises like walking, running, and cycling has been well investigated, it is less clear how open-skill exercise impacts executive function and brain activation. Therefore, we compared the acute effects of an open-skill exercise on inhibitory control and brain activation with those of a closed-skill exercise using functional near-infrared spectroscopy (fNIRS). Twenty-four young right-hand dominant adults (9 women) completed three interventions: badminton, running, and a seated rest control condition for 10 min each. The intensities of badminton and running were comparable. During each intervention, oxygen uptake and heart rate were monitored. A Stroop task composed of neutral and incongruent conditions was administrated before and after each intervention. An fNIRS system recorded hemodynamics in the prefrontal cortex to evaluate brain activation during the Stroop task. Performance on the Stroop task was significantly improved after badminton, specifically in the incongruent condition relative to in the neutral condition. On the other hand, neither running nor seated rest affected performance in the Stroop task. The fNIRS measures indicated that badminton and running had no significant influence on brain activation. These results show that a single bout of open-skill exercise enhances inhibitory control without increasing brain activation compared to closed-skill exercise, suggesting that an acute open-skill exercise induces neural efficiency. [ABSTRACT FROM AUTHOR]

Background: Numerous wearables are used in a research context to record cardiac activity although their validity and usability has not been fully investigated. The objectives of this study is the cross-model comparison of data quality at different realistic use cases (cognitive and physical tasks). The recording quality is expressed by the ability to accurately detect the QRS complex, the amount of noise in the data, and the quality of RR intervals. Methods: Five ECG devices (eMotion Faros 360°, Hexoskin Hx1, NeXus-10 MKII, Polar RS800 Multi and SOMNOtouch NIBP) were attached and simultaneously tested in 13 participants. Used test conditions included: measurements during rest, treadmill walking/running, and a cognitive 2-back task. Signal quality was assessed by a new local morphological quality parameter morphSQ which is defined as a weighted peak noise-to-signal ratio on percentage scale. The QRS detection performance was evaluated with eplimited on synchronized data by comparison to ground truth annotations. A modification of the Smith-Waterman algorithm has been used to assess the RR interval quality and to classify incorrect beat annotations. Evaluation metrics includes the positive predictive value, false negative rates, and F1 scores for beat detection performance. Results: All used devices achieved sufficient signal quality in non-movement conditions. Over all experimental phases, insufficient quality expressed by morphSQ values below 10% was only found in 1.22% of the recorded beats using eMotion Faros 360°whereas the rate was 8.67% with Hexoskin Hx1. Nevertheless, QRS detection performed well across all used devices with positive predictive values between 0.985 and 1.000. False negative rates are ranging between 0.003 and 0.017. eMotion Faros 360°achieved the most stable results among the tested devices with only 5 false positive and 19 misplaced beats across all recordings identified by the Smith-Waterman approach. Conclusion: Data quality was assessed by two new approaches: analyzing the noise-to-signal ratio using morphSQ, and RR interval quality using Smith-Waterman. Both methods deliver comparable results. However the Smith-Waterman approach allows the direct comparison of RR intervals without the need for signal synchronization whereas morphSQ can be computed locally. [ABSTRACT FROM AUTHOR]

Objective: To develop a machine learning algorithm utilizing heart rate variability (HRV) and salivary cortisol to detect the presence of acute stress among pregnant women that may be applied to future clinical research. Methods: ECG signals and salivary cortisol were analyzed from 29 pregnant women as part of a crossover study involving a standardized acute psychological stress exposure and a control non-stress condition. A filter-based features selection method was used to identify the importance of different features [heart rate (HR), time- and frequency-domain HRV parameters and salivary cortisol] for stress assessment and reduce the computational complexity. Five machine learning algorithms were implemented to assess the presence of stress with and without salivary cortisol values. Results: On graphical visualization, an obvious difference in heart rate (HR), HRV parameters and cortisol were evident among 17 participants between the two visits, which helped the stress assessment model to distinguish between stress and non-stress exposures with greater accuracy. Eight participants did not display a clear difference in HR and HRV parameters but displayed a large increase in cortisol following stress compared to the non-stress conditions. The remaining four participants did not demonstrate an obvious difference in any feature. Six out of nine features emerged from the feature selection method: cortisol, three time-domain HRV parameters, and two frequency-domain parameters. Cortisol was the strongest contributing feature, increasing the assessment accuracy by 10.3% on average across all five classifiers. The highest assessment accuracy achieved was 92.3%, and the highest average assessment accuracy was 76.5%. Conclusion: Salivary cortisol contributed a significant increase in accuracy of the assessment model compared to using a range of HRV parameters alone. Our machine learning model demonstrates acceptable accuracy in detection of acute stress among pregnant women when combining salivary cortisol with HR and HRV parameters. [ABSTRACT FROM AUTHOR]

Objectives: Patients with Panic Disorder (PD) show an abnormal stress-induced functioning of the Hypothalamic-Pituitary-adrenal (HPA)-axis. Different protocols for stress induction are of rather low relevance for the psychotherapeutic treatment. In practice, interoceptive exposure is often realized as Low Intensity Exercise (LIE), as compared to an incremental cycle exercise test to exhaustion. Currently, it is not known, whether LIE displays an effective interoceptive stressor 1.) leading to a significant anxiety induction; 2.) a comparable HPA- and Sympathetic-Adreno-Medullar (SAM)-axis response in both patients and healthy controls; 3.) stress responses under LIE are associated with treatment outcomes. Patients and methods: N = 20 patients with PD and n = 20 healthy controls were exposed to ten minutes of LIE on an exercise bike. LIE was applied as part of the interoceptive exposure, during an intensive Cognitive-Behavioral Therapy (CBT) in a day clinic. Heart rate was monitored and salivary cortisol samples collected. Before and after the LIE, state anxiety/ arousal were assessed. In order to evaluate psychopathology, the Panic and Agoraphobia Scale, Mobility Inventory, Agoraphobic Cognitions Questionnaire and Body Sensations Questionnaire were applied, before (T1) and after five weeks (T2) of an intensive CBT. Results: LIE led to a significant and similar heart rate increase in both groups. Cortisol decreased over time in both groups, especially in male patients. A higher psychopathology before, and after CBT, was associated with a significantly lower cortisol response under LIE. Conclusions: In the present study, LIE led to a divergent stress response: while there was a significant heart rate increase, cortisol decreased over time, particularly in male patients. A lower reactivity of the HPA-axis seems to be associated with a lower treatment outcome, which may affect extinction based learning. The findings suggest, that interoceptive stimuli should be designed carefully in order to be potent stressors. [ABSTRACT FROM AUTHOR]

Cardiovascular disease is the number one cause of death in the world and is a serious problem. In the case of cardiopulmonary arrest due to myocardial infarction, the survival rate is as low as 13.3% one month after resuscitation, which birthed the need for continuous heart monitoring. In this study, we develop a Ballistocardiogram (BCG) measurement system using a load cell installed on a chair and a heart rate estimation algorithm that is robust to waveform changes, with the aim of constructing a non-contact heart rate acquisition system. The proposed system was evaluated by utilizing data obtained from 13 healthy subjects and 1 subject with abnormal ECG who were simultaneously measured with ECG. The output of the BCG system was confirmed to change with the same period as the ECG data obtained as the correct answer, and the synchronization of the R-peak positions was confirmed for all cases. As a result of comparing the heart rate intervals estimated from BCG and those obtained from ECG, it was confirmed that the same heart rate variability (HRV) features could be obtained even for abnormal ECG subject. [ABSTRACT FROM AUTHOR]

Background: People living with HIV (PLHIV) present impaired muscle metaboreflex, which may lead to exercise intolerance and increased cardiovascular risk. The muscle metaboreflex adaptations to exercise training in these patients are unknown. The present study aims to investigate the effects of a supervised multimodal exercise training on hemodynamic and autonomic responses to muscle metaboreflex activation in PLHIV. Methods and design: In this randomized clinical trial protocol, 42 PLHIV aged 30–50 years will be randomly assigned at a ratio of 1:1 into an intervention or a control group. The intervention group will perform exercise training (3x/week during 12 weeks) and the control group will remain physically inactive. A reference group composed of 21 HIV-uninfected individuals will be included. Primary outcomes will be blood pressure and heart rate variability indices assessed during resting, mental stress, and activation of muscle metaboreflex by a digital sphygmomanometer and a heart rate monitor; respectively. Mental stress will be induced by the Stroop Color-Word test and muscle metaboreflex will be activated through a post-exercise circulatory arrest (PECA) protocol, being the latter performed without and with the application of a capsaicin-based analgesic balm in the exercised limb. Secondary outcomes will be heart rate, peripheral vascular resistance, stroke volume, cardiac output, blood lactate, anthropometric markers and handgrip maximal voluntary contraction. The intervention and control groups of PLHIV will be evaluated at baseline and after the intervention, while the HIV-uninfected reference group only at baseline. Discussion: The findings of the present study may help to elucidate the muscle metaboreflex adaptations to exercise training in PLHIV. Trial registration: This study will be performed at University of Rio de Janeiro State following registration at ClinicalTrials.gov as NCT04512456 on August 13, 2020. [ABSTRACT FROM AUTHOR]

The way people respond to stressful situations (i.e., stress reactivity) varies widely. Researchers typically measure stress reactivity in controlled studies, but this is limited because laboratory stressors cannot capture the variety, severity, or duration of stressors that individuals face in their daily lives. The present study examined the feasibility of using ecological momentary assessment (EMA) and a wireless electrocardiography (ECG) patch to develop an understanding of stress reactivity in natural settings. Thirty-five adult women completed EMA surveys about stressors they were exposed to while wearing a wireless ECG monitor for 7 consecutive days. Daily stressors were measured using seven questions adapted from the Daily Inventory of Stressful Events and a stressor interval was defined as the presence of at least one stressor during the EMA survey prompt. Participants wore the Cardea SOLO wireless ECG monitor (Cardiac Insight Inc., Bellevue, WA) to continuously track their heart rate. Participant-specific differences in 5-minute heart rate variability (HRV) between intervals when participants did and did not report stressors were calculated and displayed in a heat map. Survey response rate was satisfactory (72.0%, n = 588) and nearly all participants (33 out of 35) reported both stressor and non-stressor intervals. Each participant reported at least one stressor on approximately 35% of completed surveys while wearing the ECG patch. Mean wear time (6.6 days) and the duration of analyzable data with an ECG monitor were close to the 7-day study period. While many participants had lower HRV during stressor versus non-stressor intervals, the magnitude and direction of these differences varied widely. In summary, we found that a 7-day sampling scheme combining ecological momentary assessment (EMA) with HRV measured using continuous ECG monitoring was feasible and effective in capturing a variety of daily stressors and measuring autonomic stress reactivity. [ABSTRACT FROM AUTHOR]

Measures of heart rate variability (and heart rate more generally) are providing powerful insights into the physiological drivers of behaviour. Resting heart rate variability (HRV) can be used as an indicator of individual differences in temperament and reactivity to physical and psychological stress. There is increasing interest in deriving such measures from free ranging wild animals, where individuals are exposed to the natural and anthropogenic stressors of life. We describe a robust, externally mounted heart rate monitor for use in wild mammals, deployed here on wild breeding adult female grey seals (Halichoerus grypus), that delivers millisecond precise measures of inter beat intervals (IBIs), allowing computation of resting HRV parameters. Based on Firstbeat™ heart rate belts, our system allows for remote, continuous recording of IBI data from over 30 individuals simultaneously at ranges of up to 200m. We assessed the accuracy of the IBI data provided by the Firstbeat™ system using concurrent IBI data derived from in-field electrocardiogram (ECG) recordings. Bland-Altmann analyses demonstrated high correspondence between the two sets of IBI data, with a mean difference of 0.87±0.16ms. We used generalized additive mixed-effects models to examine the impact of the default Firstbeat™ software artefact correction procedure upon the generation of anomalous data (flats and stairs). Artefact correction and individual activity were major causes of flats and stairs. We used simulations and models to assess the impact of these errors on estimates of resting HRV and to inform criteria for subsampling relatively error free IBI traces. These analyses allowed us to establish stringent filtering procedures to remove traces with excessive numbers of artefacts, including flats and stairs. Even with strict criteria for removing potentially erroneous data, the abundance of data yielded by the Firstbeat™ system provides the potential to extract robust estimates of resting HRV. We discuss the advantages and limitations of our system for applications beyond the study system described here. [ABSTRACT FROM AUTHOR]

Horses have the ability to generate a remarkable repertoire of facial expressions, some of which have been linked to the affective component of pain. This study describes the facial expressions in healthy horses free of pain before and during transportation and social isolation, which are putatively stressful but ordinary management procedures. Transportation was performed in 28 horses by subjecting them to short-term road transport in a horse trailer. A subgroup (n = 10) of these horses was also subjected to short-term social isolation. During all procedures, a body-mounted, remote-controlled heart rate monitor provided continuous heart rate measurements. The horses' heads were video-recorded during the interventions. An exhaustive dataset was generated from the selected video clips of all possible facial action units and action descriptors, time of emergency, duration, and frequency according to the Equine Facial Action Coding System (EquiFACS). Heart rate increased during both interventions (p<0.01), confirming that they caused disruption in sympato-vagal balance. Using the current method for ascribing certain action units (AUs) to specific emotional states in humans and a novel data-driven co-occurrence method, the following facial traits were observed during both interventions: eye white increase (p<0.001), nostril dilator (p<0.001), upper eyelid raiser (p<0.001), inner brow raiser (p = 0.042), tongue show (p<0.001). Increases in 'ear flicker' (p<0.001) and blink frequency (p<0.001) were also seen. These facial actions were used to train a machine-learning classifier to discriminate between the high-arousal interventions and calm horses, which achieved at most 79% accuracy. Most facial features identified correspond well with previous findings on behaviors of stressed horses, for example flared nostrils, repetitive mouth behaviors, increased eye white, tongue show, and ear movements. Several features identified in this study of pain-free horses, such as dilated nostrils, eye white increase, and inner brow raiser, are used as indicators of pain in some face-based pain assessment tools. In order to increase performance parameters in pain assessment tools, the relations between facial expressions of stress and pain should be studied further. [ABSTRACT FROM AUTHOR]

Introduction: The analysis of heart rate variability (HRV) has proven to be an important tool for the management of autonomous nerve system in both surgical and critically ill patients. We conducted this study to show the different spectral frequency and time domain parameters of HRV as a prospective predictor for critically ill patients, and in particular for COVID-19 patients who are on mechanical ventilation. The hypothesis is that most severely ill COVID-19 patients have a depletion of the sympathetic nervous system and a predominance of parasympathetic activity reflecting the remaining compensatory anti-inflammatory response. Materials and methods: A single-center, prospective, observational pilot study which included COVID-19 patients admitted to the Surgical Intensive Care Unit was conducted. The normalized high-frequency component (HFnu), i.e. ANIm, and the standard deviation of RR intervals (SDNN), i.e. Energy, were recorded using the analgesia nociception index monitor (ANI). To estimate the severity and mortality we used the SOFA score and the date of discharge or date of death. Results: A total of fourteen patients were finally included in the study. ANIm were higher in the non-survivor group (p = 0.003) and were correlated with higher IL-6 levels (p = 0.020). Energy was inversely correlated with SOFA (p = 0.039) and fewer survival days (p = 0.046). A limit value at 80 of ANIm, predicted mortalities with a sensitivity of 100% and specificity of 85.7%. In the case of Energy, a limit value of 0.41 ms predicted mortality with all predictive values of 71.4%. Conclusion: A low autonomic nervous system activity, i.e. low SDNN or Energy, and a predominance of the parasympathetic system, i.e. low HFnu or ANIm, due to the sympathetic depletion in COVID-19 patients are associated with a worse prognosis, higher mortality, and higher IL-6 levels. [ABSTRACT FROM AUTHOR]

Heart rate variability (HRV) measurements via ambulatory monitors have become common. We examined the validity of recording R-R intervals using the Polar V800™ compared to 12-lead electrocardiograms (ECG) among middle-aged (44.7±10.1years); overweight to obese (29.8±4.3 kg.m-2) adults (n = 25) with hypertension (132.3±12.2/ 84.3±10.2 mmHg). After resting for 5-min in the supine position, R-R intervals were simultaneously recorded using the Polar V800™ and the 12-lead ECG. Artifacts present in uncorrected (UN) R-R intervals were corrected with the Kubios HRV Premium (ver. 3.2.) automatic (AC) and threshold-based (TBC) correction, and manual correction (MC) methods. Intra-class correlation coefficients (ICC), Bland-Altman limits of agreement (LoA), and effect sizes (ES) were calculated. We detected 71 errors with the Polar V800™ for an error rate of 0.85%. The bias (LoAs), ES, and ICC between UN and ECG R-R intervals were 0.69ms (-215.80 to +214.42ms), 0.004, and 0.79, respectively. Correction of artifacts improved the agreeability between the Polar V800™ and ECG HRV measures. The biases (LoAs) between the AC, TBC, and MC and ECG R-R intervals were 3.79ms (-130.32 to +137.90ms), 1.16ms (-92.67 to +94.98ms), and 0.37ms (-41.20 to +41.94ms), respectively. The ESs of AC, TBC, and MC were 0.024, 0.008, and 0.002, and ICCs were 0.91, 0.95, and 1.00, respectively. R-R intervals measured using the Polar V800™ compared to 12-lead ECG were comparable in adults with hypertension, especially after the artifacts corrected by MC. However, TBC correction also yielded acceptable results. [ABSTRACT FROM AUTHOR]

Validation of heart rate responses in wearable technology devices is generally composed of laboratory-based protocols that are steady state in nature and as a result, high accuracy measures are returned. However, there is a need to understand device validity in applied settings that include varied intensities of exercise. The purpose was to determine concurrent heart rate validity during trail running. Twenty-one healthy participants volunteered (female n = 10, [mean (SD)]: age = 31 [11] years, height = 173.0 [7] cm, mass = 75.6 [13] kg). Participants were outfitted with wearable technology devices (Garmin Fenix 5 wristwatch, Jabra Elite Sport earbuds, Motiv ring, Scosche Rhythm+ forearm band, Suunto Spartan Sport watch with accompanying chest strap) and completed a self-paced 3.22 km trail run while concurrently wearing a criterion heart rate strap (Polar H7 heart rate monitor). The trail runs were out-and-back with the first 1.61 km in an uphill direction, and the 1.61 return being downhill in nature. Validity was determined through three methods: Mean Absolute Percent Error (MAPE), Bland-Altman Limits of Agreement (LOA), and Lin's Concordance Coefficient (rC). Validity measures overall are as follows: Garmin Fenix 5 (MAPE = 13%, LOA = -32 to 162, rC = 0.32), Jabra Elite Sport (MAPE = 23%, LOA = -464 to 503, rC = 0.38), Motiv ring (MAPE = 16%, LOA = -52 to 96, rC = 0.29), Scosche Rhythm+ (MAPE = 6%, LOA = -114 to 120, rC = 0.79), Suunto Spartan Sport (MAPE = 2%, LOA = -62 to 61, rC = 0.96). All photoplethysmography-based (PPG) devices displayed poor heart rate agreement during variable intensity trail running. Until technological advances occur in PPG-based devices allowing for acceptable agreement, heart rate in outdoor environments should be obtained using an ECG-based chest strap that can be connected to a wristwatch or other comparable receiver. [ABSTRACT FROM AUTHOR]

Objective: Exercise capacity is impaired in Fontan palliated patients. The change in daily activity behaviour with an increase in sedentary lifestyle results in low physical activity levels. This might have a greater impact on patients with chronic heart disease in contrast to healthy controls. For a better understanding, we compared data from cardiopulmonary exercise testing (CPET) with heart rates and physical activity in daily life. Methods: 21 Fontan patients and 20 age, sex and BMI matched controls underwent CPET and 5 days of daily life activity tracking with a triaxial accelerometer (wGT3x-BT, Actigraph) including heart rate monitoring with an optical heart rate sensor. Results: 27% of our Fontan teenagers and 71% of the Fontan adults reached the specific WHO recommendations for moderate to vigorous physical activity (MVPA) during everyday life (EDL), without differences to controls. There was a strong correlation between MVPA and V˙O2peak for all Fontan patients (p = 0.0035, Pearson r = 0.788). Daily MVPA correlated to peak oxygen uptake and lactate production. Up to workloads of 2 W/kg and in daily life heart rates in Fontan patients were similar to controls. Conclusions: Daily MVPA is alarmingly low without any differences between Fontan patients and controls. Heart rate behaviour was similar and does not seem to be a limiting factor for physical activity in daily life. Higher intensity activities should be implemented regularly in EDL for Fontan patients. Proof is needed as to whether sports in moderate or possibly even in vigorous activity (e.g. high-intensity interval training) improve exercise capacity the most. [ABSTRACT FROM AUTHOR]

Background: Atrial Fibrillation is the most common arrhythmia worldwide with a global age adjusted prevalence of 0.5% in 2010. Anticoagulation treatment using warfarin or direct oral anticoagulants is effective in reducing the risk of AF-related stroke by approximately two-thirds and can provide a 10% reduction in overall mortality. There has been increased interest in detecting AF due to its increased incidence and the possibility to prevent AF-related strokes. Inexpensive consumer devices which measure the ECG may have the potential to accurately detect AF but do not generally incorporate diagnostic algorithms. Machine learning algorithms have the potential to improve patient outcomes particularly where diagnoses are made from large volumes or complex patterns of data such as in AF. Methods: We designed a novel AF detection algorithm using a de-correlated Lorenz plot of 60 consecutive RR intervals. In order to reduce the volume of data, the resulting images were compressed using a wavelet transformation (JPEG200 algorithm) and the compressed images were used as input data to a Support Vector Machine (SVM) classifier. We used the Massachusetts Institute of Technology (MIT)—Beth Israel Hospital (BIH) Atrial Fibrillation database and the MIT-BIH Arrhythmia database as training data and verified the algorithm performance using RR intervals collected using an inexpensive consumer heart rate monitor device (Polar-H7) in a case-control study. Results: The SVM algorithm yielded excellent discrimination in the training data with a sensitivity of 99.2% and a specificity of 99.5% for AF. In the validation data, the SVM algorithm correctly identified AF in 79/79 cases; sensitivity 100% (95% CI 95.4%-100%) and non-AF in 328/336 cases; specificity 97.6% (95% CI 95.4%-99.0%). Conclusions: An inexpensive wearable heart rate monitor and machine learning algorithm can be used to detect AF with very high accuracy and has the capability to transmit ECG data which could be used to confirm AF. It could potentially be used for intermittent screening or continuously for prolonged periods to detect paroxysmal AF. Further work could lead to cost-effective and accurate estimation of AF burden and improved risk stratification in AF. [ABSTRACT FROM AUTHOR]

Heart rate can be used as a measure of cognitive engagement. We measured average student heart rates during medical school lecture classes using wristwatch-style monitors. Analysis of 42 classes showed a steady decline in heart rate from the beginning to end of a lecture class. Active learning sessions (peer-discussion based problem solving) resulted in a significant uptick in heart rate, but this returned to the average level immediately following the active learning period. This is the first statistically robust assessment of changes in heart rate during the course of college lecture classes and indicates that personal heart rate monitors may be useful tools for assessment of different teaching modalities. The key findings suggest that the value of active learning within the classroom resides in the activity itself and not in an increase in engagement or reset in attention during the didactic period following an active learning session. [ABSTRACT FROM AUTHOR]

Remote photoplethysmography (rPPG) allows contactless monitoring of human cardiac activity through a video camera. In this study, we assessed the accuracy and precision for heart rate measurements of the only consumer product available on the market, namely the FacereaderTM rPPG by Noldus, with respect to a gold standard electrocardiograph. Twenty-four healthy participants were asked to sit in front of a computer screen and alternate two periods of rest with two stress tests (i.e. Go/No-Go task), while their heart rate was simultaneously acquired for 20 minutes using the ECG criterion measure and the FacereaderTM rPPG. Results show that the FacereaderTM rPPG tends to overestimate lower heart rates and underestimate higher heart rates compared to the ECG. The Facereader™ rPPG revealed a mean bias of 9.8 bpm, the 95% limits of agreement (LoA) ranged from almost -30 up to +50 bpm. These results suggest that whilst the rPPG FacereaderTM technology has potential for contactless heart rate monitoring, its predictions are inaccurate for higher heart rates, with unacceptable precision across the entire range, rendering its estimates unreliable for monitoring individuals. [ABSTRACT FROM AUTHOR]

Objective: Although high intensity physical activities may represent a great proportion of the total energy expenditure in active people, only sparse studies have investigated the accuracy of wearable monitors to assess activity related energy expenditure (AEE) during high intensity exercises. Therefore, the purpose of the present study was to investigate the accuracy of the Actiheart, a light portable monitor estimating AEE based on heart rate (HR) and activity counts (ACT), during two popular activities (running and cycling) performed at high intensities. The benefit of an individual calibration of the HR-AEE relationship established during a preliminary maximal test was also evaluated. Methods: AEE was estimated in eighteen active adults (4 women and 14 men; 25 ± 4 yr) with indirect calorimetry using a respiratory gas analysis system (reference method) and the Actiheart during 5-min running and cycling at 60, 75 and 85% of maximal oxygen uptake (VO2max) previously determined during a maximal test performed on a treadmill or cycle ergometer. For the Actiheart, AEE was estimated either using the group or individual calibrated equations available in the dedicated software, and their respective HR, ACT or combined HR/ACT algorithms. Results: When the HR algorithm was used for cycling and the HR or HR/ACT algorithms for running, AEE measured by the Actiheart increased proportionally to exercise intensity from 60 to 85% VO2max (P<0.001). Compared to indirect calorimetry, the Actiheart group calibrated equations slightly to moderately underestimated (3 to 20%) AEE for the three exercise intensities (P<0.001). Accuracy of AEE estimation was greatly improved by individual calibration of the HR-AEE relationship (underestimation below 5% and intraclass correlation coefficient [ICC]: 0.79–0.93) compared to group calibration (ICC: 0.64–0.79). Conclusion: The Actiheart enables to assess AEE during high intensity running and cycling when the appropriate algorithm is applied. Since an underestimation was present for group calibration, an individual and sport-specific calibration should be performed when a high accuracy is required. [ABSTRACT FROM AUTHOR]

Pig experiments have played an important role in medical breakthroughs during the last century. In fact, pigs are one of the major animal species used in translational research, surgical models and procedural training due to their anatomical and physiological similarities to humans. To ensure high bioethical standards in animal trials, new directives have been implemented, among others, to refine the procedures and minimize animals' stress and pain. This paper presents a contactless motion-based approach for monitoring cardiorespiratory signals (heart rate and respiratory rate) in anesthetized pigs using infrared thermography. Heart rate monitoring is estimated by measuring the vibrations (precordial motion) of the chest caused by the heartbeat. Respiratory rate, in turn, is computed by measuring the mechanical chest movements that accompany the respiratory cycle. To test the feasibility of this approach, thermal videos of 17 anesthetized pigs were acquired and analyzed. A high agreement between infrared thermography and a gold standard (electrocardiography and capnography-derived respiratory rate) was achieved. The mean absolute error averaged 3.43 ± 3.05 bpm and 0.27 ± 0.48 breaths/min for heart rate and respiratory rate, respectively. In sum, infrared thermography is capable of assessing cardiorespiratory signals in pigs. Future work should be conducted to evaluate infared thermography capability of capturing information for long term monitoring of research animals in a diverse set of facilities. [ABSTRACT FROM AUTHOR]

Multiple cross-sectional studies have shown that regular complex exercises, which require cognitive demands (e.g., decision making) and various motions, are associated with greater positive effects on executive functions compared to simple exercises. However, the evidence of a single bout of complex exercises is mixed, and investigations on the acute effect of complex exercise using a well-controlled within-subjects research design are few. Therefore, we compared the acute effects of complex exercise on inhibitory functions with those of simple running. Twenty young adults performed three interventions, which were running, badminton, and seated rest as a control condition for 10 min each. During each intervention, oxygen consumption and heart rate were monitored. A Stroop test and a reverse-Stroop test were completed before and after each intervention. The intensities of the badminton and running were equivalent. Badminton significantly improved performance on the Stroop task compared to seated rest; however, running did not enhance performance on the Stroop task relative to seated rest. A single bout of complex exercise elicits a larger benefit to inhibitory function than a single bout of simple exercise. However, the benefit of complex exercise may vary depending on the type of executive functions. [ABSTRACT FROM AUTHOR]

The aim of the present study was to assess the accuracy of heart rate to estimate energy cost during eight resistance exercises performed at low intensities: half squat, 45° inclined leg press, leg extension, horizontal bench press, 45° inclined bench press, lat pull down, triceps extension and biceps curl. 56 males (27.5 ± 4.9 years, 1.78 ± 0.06 m height, 78.67 ± 10.7 kg body mass and 11.4 ± 4.1% estimated body fat) were randomly divided into four groups of 14 subjects each. Two exercises were randomly assigned to each group and subjects performed four bouts of 4-min constant-intensity at each assigned exercise: 12%, 16%, 20% and 24% 1-RM. Exercise and intensity order were random. Each subject performed no more than 2 bouts in the same testing session. A minimum recovery of 24h was kept between sessions. During testing VO2 was measured with Cosmed K4b2 and heart rate was measured with Polar V800 monitor. Energy cost was calculated from mean VO2 during the last 30-s of each bout by using the energy equivalent 1 ml O2 = 5 calorie. Linear regressions with heart rate as predictor and energy cost as dependent variable were build using mean data from all subjects. Robustness of the regression lines was given by the scatter around the regression line (Sy.x) and Bland-Altman plots confirmed the agreement between measured and estimated energy costs. Significance level was set at p≤0.05. The regressions between heart rate and energy cost in the eight exercises were significant (p<0.01) and robustness was: half squat (Sy.x = 0,48 kcal·min-1), 45° inclined leg press (Sy.x = 0,54 kcal·min-1), leg extension (Sy.x = 0,59 kcal·min-1), horizontal bench press (Sy.x = 0,47 kcal·min-1), 45° inclined bench press (Sy.x = 0,54 kcal·min-1), lat pull down (Sy.x = 0,28 kcal·min-1), triceps extension (Sy.x = 0,08 kcal·min-1) and biceps curl (Sy.x = 0,13 kcal·min-1). We conclude that during low-intensity resistance exercises it is possible to estimate aerobic energy cost by wearable heart rate monitors with errors below 10% in healthy young trained males. [ABSTRACT FROM AUTHOR]

Introduction: Wrist-mounted motion sensors can quantify the volume and intensity of physical activities, but little is known about their long-term validity. Our aim was to validate a wrist motion sensor in estimating daily energy expenditure, including any change induced by long-term participation in endurance and strength training. Supplemental heart rate monitoring during weekly exercise was also investigated. Methods: A 13-day doubly labeled water (DLW) measurement of total energy expenditure (TEE) was performed twice in healthy male subjects: during two last weeks of a 12-week Control period (n = 15) and during two last weeks of a 12-week combined strength and aerobic Training period (n = 13). Resting energy expenditure was estimated using two equations: one with body weight and age, and another one with fat-free mass. TEE and activity induced energy expenditure (AEE) were determined from motion sensor alone, and from motions sensor combined with heart rate monitor, the latter being worn during exercise only. Results: When body weight and age were used in the calculation of resting energy expenditure, the motion sensor data alone explained 78% and 62% of the variation in TEE assessed by DLW at the end of Control and Training periods, respectively, with a bias of +1.75 (p <.001) and +1.19 MJ/day (p = .002). When exercise heart rate data was added to the model, the combined wearable device approach explained 85% and 70% of the variation in TEE assessed by DLW with a bias of +1.89 and +1.75 MJ/day (p <.001 for both). While significant increases in TEE and AEE were detected by all methods as a result of participation in regular training, motion sensor approach underestimated the change measured by DLW: +1.13±0.66 by DLW, +0.59±0.69 (p = .004) by motion sensor, and +0.98±0.70 MJ/day by combination of motion sensor and heart rate. Use of fat-free mass in the estimation of resting energy expenditure removed the biases between the wearable device estimations and the golden standard reference method of TEE and demonstrated a training-induced increase in resting energy expenditure by +0.18±0.13 MJ/day (p <.001). Conclusions: Wrist motion sensor combined with a heart rate monitor during exercise sessions, showed high agreement with the golden standard measurement of daily TEE and its change induced by participation in a long-term training protocol. The positive findings concerning the validity, especially the ability to follow-up the change associated with a lifestyle modification, can be considered significant because they partially determine the feasibility of wearable devices as quantifiers of health-related behavior. [ABSTRACT FROM AUTHOR]

A high standard of physical fitness is an essential characteristic of drug detection dogs because it affects not only their ability to sustain high activity levels but also their attention and olfaction efficiency. Nutritional supplements could improve physical fitness by modulating energy metabolism, oxidative processes, and perceived fatigue. The aim of this study was to investigate the physiological and biochemical changes induced by submaximal exercise on drug detection dogs (German Shepherd breed) and to assess whether a dietary supplement improves their physical fitness. During a drug detection dog training course, seven dogs were fed with a basal diet (Control Group) for three-month period, while a further seven dogs were fed with a basal diet as well as a daily nutritional supplement containing branched-chain and limiting amino acids, carnitine, vitamins, and octacosanol (Treatment Group). At the end of this period, individual physical fitness was assessed by making each subject take a graded treadmill exercise test. A human heart rate monitor system was used to record the dog’s heart rate (HR) during the treadmill exercise and the subsequent recovery period. The parameters related to HR were analysed using nonparametric statistics. Blood samples were collected before starting the nutritional supplement treatment, before and after the treadmill exercise and following recovery. Linear mixed models were used. The dietary supplements accelerated HR recovery, as demonstrated by the lower HR after recovery (P<0.05) and Time constants of HR decay (P<0.05), and by the higher Absolute HR Recovered (P<0.05) recorded in the Treatment group compared with the Control dogs. The supplemented dogs showed the lowest concentrations of creatine kinase (CK; P<0.001), aspartate aminotransferase (AST, P<0.05) and non-esterified fatty acids (NEFA; P<0.01) suggesting a reduction in muscle damage and improvement of energy metabolism. These data suggest that this combined supplement can significantly enhance the physical fitness of drug detection dogs. [ABSTRACT FROM AUTHOR]

Background: Optical measurement techniques and recent advances in wearable technology have made heart rate (HR) sensing simpler and more affordable. Objectives: The Polar OH1 is an arm worn optical heart rate monitor. The objectives of this study are two-fold; 1) to validate the OH1 optical HR sensor with the gold standard of HR measurement, electrocardiography (ECG), over a range of moderate to high intensity physical activities, 2) to validate wearing the OH1 at the temple as an alternative location to its recommended wearing location around the forearm and upper arm. Methods: Twenty-four individuals participated in a physical exercise protocol, by walking on a treadmill and riding a stationary spin bike at different speeds while the criterion measure, ECG and Polar OH1 HR were recorded simultaneously at three different body locations; forearm, upper arm and the temple. Time synchronised HR data points were compared using Bland-Altman analyses and intraclass correlation. Results: The intraclass correlation between the ECG and Polar OH1, for the aggregated data, was 0.99 and the estimated mean bias ranged 0.27–0.33 bpm for the sensor locations. The three sensors exhibited a 95% limit of agreement (LoA: forearm 5.22, -4.68 bpm; upper arm 5.15, -4.49; temple 5.22, -4.66). The mean of the ECG HR for the aggregated data was 112.15 ± 24.52 bpm. The intraclass correlation of HR values below and above this mean were 0.98 and 0.99 respectively. The reported mean bias ranged 0.38–0.47 bpm (95% LoA: forearm 6.14, -5.38 bpm; upper arm 6.07, -5.13 bpm; temple 6.09, -5.31 bpm), and 0.15–0.16 bpm (95% LoA: forearm 3.99, -3.69 bpm; upper arm 3.90, -3.58 bpm; temple 4.06, -3.76 bpm) respectively. During different exercise intensities, the intraclass correlation ranged 0.95–0.99 for the three sensor locations. During the entire protocol, the estimated mean bias was in the range -0.15–0.55 bpm, 0.01–0.53 bpm and -0.37–0.48 bpm, for the forearm, upper arm and temple locations respectively. The corresponding upper limits of 95% LoA were 3.22–7.03 bpm, 3.25–6.82 bpm and 3.18–7.04 bpm while the lower limits of 95% LoA were -6.36–(-2.35) bpm, -6.46–(-2.30) bpm and -7.42–(-2.41) bpm. Conclusion: Polar OH1 demonstrates high level of agreement with the criterion measure ECG HR, thus can be used as a valid measure of HR in lab and field settings during moderate and high intensity physical activities. [ABSTRACT FROM AUTHOR]

Physical fatigue and pronated feet constitute two risk factors for running-related lower limb injuries. Accordingly, different running shoe companies designed anti-pronation shoes with medial support to limit over pronation in runners. However, there is little evidence on the effectiveness and clinical relevance of anti-pronation shoes. This study examined lower limb kinematics and kinetics in young female runners with pronated feet during running with anti-pronation versus regular (neutral) running shoes in unfatigued and fatigued condition. Twenty-six female runners aged 24.1±5.6 years with pronated feet volunteered to participate in this study. Kinetic (3D Kistler force plate) and kinematic analyses (Vicon motion analysis system) were conducted to record participants’ ground reaction forces and joint kinematics when running with anti-pronation compared with neutral running shoes. Physical fatigue was induced through an individualized submaximal running protocol on a motorized treadmill using rate of perceived exertion and heart rate monitoring. The statistical analyses indicated significant main effects of “footwear” for peak ankle inversion, peak ankle eversion, and peak hip internal rotation angles (p<0.03; d = 0.46–0.95). Pair-wise comparisons revealed a significantly greater peak ankle inversion angle (p<0.03; d = 0.95; 2.70°) and smaller peak eversion angle (p<0.03; d = 0.46; 2.53°) when running with anti-pronation shoes compared with neutral shoes. For kinetic data, significant main effects of “footwear” were found for peak ankle dorsiflexor moment, peak knee extensor moment, peak hip flexor moment, peak hip extensor moment, peak hip abductor moment, and peak hip internal rotator moment (p<0.02; d = 1.00–1.79). For peak positive hip power in sagittal and frontal planes and peak negative hip power in horizontal plane, we observed significant main effects of “footwear” (p<0.03; d = 0.92–1.06). Pairwise comparisons revealed that peak positive hip power in sagittal plane (p<0.03; d = 0.98; 2.39 w/kg), peak positive hip power in frontal plane (p = 0.014; d = 1.06; 0.54 w/kg), and peak negative hip power in horizontal plane (p<0.03; d = 0.92; 0.43 w/kg) were greater with anti-pronation shoes. Furthermore, the statistical analyses indicated significant main effects of “Fatigue” for peak ankle inversion, peak ankle eversion, and peak knee external rotation angles. Pair-wise comparisons revealed a fatigue-induced decrease in peak ankle inversion angle (p<0.01; d = 1.23; 2.69°) and a fatigue-induced increase in peak knee external rotation angle (p<0.05; d = 0.83; 5.40°). In addition, a fatigue-related increase was found for peak ankle eversion (p<0.01; d = 1.24; 2.67°). For kinetic data, we observed a significant main effect of “Fatigue” for knee flexor moment, knee internal rotator moment, and hip extensor moment (p<0.05; d = 0.83–1.01). The statistical analyses indicated significant a main effect of “Fatigue” for peak negative ankle power in sagittal plane (p<0.01; d = 1.25). Finally, we could not detect any significant footwear by fatigue interaction effects for all measures of joint kinetics and kinematics. Running in anti-pronation compared with neutral running shoes produced lower peak moments and powers in lower limb joints and better control in rear foot eversion. Physical fatigue increased peak moments and powers in lower limb joints irrespective of the type of footwear. [ABSTRACT FROM AUTHOR]

Background and objectives: ECG signal is relatively weak and vulnerable to various noise interferences, such as electromyography. There will be robustness problems when detecting the instantaneous heart rate independently. In some cases, multiple human physiologic parameters are monitored to help in heart rate detection. Methods: In this paper, an algorithm that marks the R-wave peaks with the help of simultaneously recorded continuous blood pressure is proposed and tested on two databases. One database, called the challenge database, is provided by the PhysioNet/Computing in Cardiology Challenge 2014, and the other is the MGH/MF waveform database. Results: The final scores of the proposed algorithm are 97.3% for the challenge database and 96.6% for the MGH/MF waveform database. Conclusions: The experimental results show that this algorithm has high detection accuracy and a relatively strong robustness. [ABSTRACT FROM AUTHOR]

Non-invasive fetal electrocardiography (ECG) is based on the acquisition of signals from abdominal surface electrodes. The composite abdominal signal consists of the maternal electrocardiogram along with the fetal electrocardiogram and other electrical interferences. These recordings allow for the acquisition of valuable and reliable information that helps ensure fetal well-being during pregnancy. This paper introduces a procedure for fetal heart rate extraction from a single-channel abdominal ECG signal. The procedure is composed of three main stages: a method based on wavelet for signal denoising, a new clustering-based methodology for detecting fetal QRS complexes, and a final stage to correct false positives and false negatives. The novelty of the procedure thus relies on using clustering techniques to classify singularities from the abdominal ECG into three types: maternal QRS complexes, fetal QRS complexes, and noise. The amplitude and time distance of all the local maxima followed by a local minimum were selected as features for the clustering classification. A wide set of real abdominal ECG recordings from two different databases, providing a large range of different characteristics, was used to illustrate the efficiency of the proposed method. The accuracy achieved shows that the proposed technique exhibits a competitve performance when compared to other recent works in the literature and a better performance over threshold-based techniques. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this pilot study was to evaluate the potential of a new noninvasive optical measurement of muscle oxygenation (MOx) to identify shock severity in patients with suspected sepsis. Methods: We enrolled 51 adult patients in the emergency department (ED) who presented with possible sepsis using traditional Systematic Inflammatory Response Syndrome criteria or who triggered a “Code Sepsis.” Noninvasive MOx measurements were made from the first dorsal interosseous muscles of the hand once potential sepsis/septic shock was identified, as soon as possible after admission to the ED. Shock severity was defined by concurrent systolic blood pressure, heart rate, and serum lactate levels. MOx was also measured in a control group of 17 healthy adults. Results: Mean (± SD) MOx in the healthy control group was 91.0 ± 5.5% (n = 17). Patients with mild, moderate, and severe shock had mean MOx values of 79.4 ± 21.2%, 48.6 ± 28.6%, and 42.2 ± 4.7%, respectively. Mean MOx for the mild and moderate shock severity categories were statistically different from healthy controls and from each other based on two-sample t-tests (p < 0.05). Conclusions: We demonstrate that noninvasive measurement of MOx was associated with clinical assessment of shock severity in suspected severe sepsis or septic shock. The ability of MOx to detect even mild septic shock has meaningful implications for emergency care, where decisions about triage and therapy must be made quickly and accurately. Future longitudinal studies may validate these findings and the value of MOx in monitoring patient status as treatment is administered. [ABSTRACT FROM AUTHOR]

Reference 1 Aragón-Benedí C, Oliver-Forniés P, Galluccio F, Yamak Altinpulluk E, Ergonenc T, El Sayed Allam A, et al. (2021) Is the heart rate variability monitoring using the analgesia nociception index a predictor of illness severity and mortality in critically ill patients with COVID-19? The correct sentence is: A low autonomic nervous system activity, i.e. low SDNN or Energy, and a predominance of the parasympathetic system, i.e. high HFnu or ANIm, due to the sympathetic depletion in COVID-19 patients are associated with a worse prognosis, higher mortality, and higher IL-6 levels. Correction: Is the heart rate variability monitoring using the analgesia nociception index a predictor of illness severity and mortality in critically ill patients with COVID-19?. [Extracted from the article]