Pre-existing parasympathetic dominance seems to cause persistent heart rate slowing after 6 months of fingolimod treatment in patients with multiple sclerosis.

PURPOSE: Vagomimetic fingolimod effects cause heart rate (HR) slowing upon treatment initiation but wear off with sphingosine-1-phosphate receptor downregulation. Yet, prolonged HR slowing may persist after months of fingolimod treatment. We evaluated whether cardiovascular autonomic modulation differs before and 6 months after fingolimod initiation between patients with RRMS with and without initially prolonged HR slowing upon fingolimod initiation. METHODS: In 34 patients with RRMS, we monitored RR intervals (RRI) and blood pressure (BP), at rest and upon standing up before fingolimod initiation. Six hours and 6 months after fingolimod initiation, we repeated recordings at rest. At the three time points, we calculated autonomic parameters, including RRI standard deviation (RRI-SD), RRI-total-powers, RMSSD, RRI high-frequency [HF] powers, RRI and BP low-frequency (LF) powers, and baroreflex sensitivity (BRS). Between and among patients with and without prolonged HR slowing upon fingolimod initiation, we compared all parameters assessed at the three time points (analysis of variance [ANOVA] with post hoc testing; significance: p < 0.05). RESULTS: Six hours after fingolimod initiation, all patients had decreased HRs but increased RRIs, RRI-SDs, RMSSDs, RRI-HF-powers, RRI-total-powers, and BRS; 11 patients had prolonged HR slowing. Before fingolimod initiation, these 11 patients did not decrease parasympathetic RMSSDs and RRI-HF-powers upon standing up. After 6 months, all parameters had reapproached pretreatment values but the 11 patients with prolonged HR slowing had lower HRs while the other 23 patients had lower parasympathetic RMSSDs and RRI-HF-powers, and BRS than before fingolimod initiation. CONCLUSION: Our patients with prolonged HR slowing upon fingolimod initiation could not downregulate cardiovagal modulation upon standing up even before fingolimod initiation, and 6 months after fingolimod initiation still had more parasympathetic effect on HR while cardiovagal modulation and BRS were attenuated in the other 23 patients. Pre-existing parasympathetic predominance may cause prolonged HR slowing upon fingolimod initiation.

Investigating the eye-catching effect in the entrance zone of highway tunnels through heart rate variability analysis.

OBJECTIVE: This study aimed to investigate the influence of visual attraction conditions on drivers' cognitive workload and physiological responses, assessed through heart rate variability (HRV) indicators. The study examined four experimental scenarios, including a baseline condition and three visual attractions (landscape-style architecture, tip slogan, and billboard) at tunnel entrances. METHODS: HRV indicators, including RMSSD, SDNN, LF, and LF/HF ratio, were analyzed to assess cognitive workload and physiological states. The study collected data from a sample of drivers under each experimental scenario and compared the HRV measures across conditions. RESULTS: The presence of visual attractions at tunnel entrances significantly impacted drivers' HRV. The introduction of visual attractions resulted in decreased RMSSD and SDNN values, indicating increased cognitive workload and reduced adaptability of the autonomic nervous system. Moreover, visual attractions led to increased LF values and LF/HF ratio, suggesting heightened sympathetic activation and potential cognitive engagement. CONCLUSIONS: Visual attractions have a significant impact on drivers' cognitive workload and physiological responses. Designing tunnel entrances with a balance between visual attractiveness and cognitive demands is essential to optimize drivers' cognitive performance and overall driving experience. These findings provide valuable insights for transportation authorities and designers to create safer and more user-friendly tunnel environments.

Feature importance for estimating rating of perceived exertion from cardiorespiratory signals using machine learning.

Introduction: The purpose of this study is to investigate the importance of respiratory features, relative to heart rate (HR), when estimating rating of perceived exertion (RPE) using machine learning models. Methods: A total of 20 participants aged 18 to 43 were recruited to carry out Yo-Yo level-1 intermittent recovery tests, while wearing a COSMED K5 portable metabolic machine. RPE information was collected throughout the Yo-Yo test for each participant. Three regression models (linear, random forest, and a multi-layer perceptron) were tested with 8 training features (HR, minute ventilation (VE), respiratory frequency (Rf), volume of oxygen consumed (VO2), age, gender, weight, and height). Results: Using a leave-one-subject-out cross validation, the random forest model was found to be the most accurate, with a root mean square error of 1.849, and a mean absolute error of 1.461 ± 1.133. Feature importance was estimated via permutation feature importance, and VE was found to be the most important for all three models followed by HR. Discussion: Future works that aim to estimate RPE using wearable sensors should therefore consider using a combination of cardiovascular and respiratory data.

Validity of the estimated core temperature algorithm during real-world prolonged walking exercise under warm ambient conditions.

BACKGROUND: Non-invasive methods to estimate core body temperature (TC) are increasingly available. We examined the group-level and individual participant-level validity of the Estimated Core Temperature (ECTemp™) algorithm to estimate TC based on sequential heart rate (HR) measurements during real-world prolonged walking exercise in warm ambient conditions. METHODS: Participants walked 30 (n = 3), 40 (n = 13) or 50 (n = 2) km on a self-selected pace during which TC was measured every minute using an ingestible temperature capsule. HR was measured every second and used to compute the estimated core temperature (TC-est) using the ECTemp™ algorithm. Bland-Altman analyses were performed to assess agreement between TC and TC-est. A systematic bias <0.1 °C was considered acceptable. RESULTS: 18 participants (56 ± 16 years, 11 males) walked for 549 min (range 418-645 min), while ambient temperature increased from 22 °C to 29 °C. Average HR was 108 ± 13 bpm and TC ranged from 36.9 to 39.2 °C, whereas TC-est ranged from 36.8 to 38.9 °C (n = 8572 observations). Group level data revealed a systematic bias of 0.09 °C (p < 0.001) with limits of agreements of ±0.44 °C. A weak correlation was found between TC and TC-est (r = 0.28; p < 0.001). Large inter-individual differences in bias (range -0.45 °C to 0.62 °C) and correlation coefficients (range -0.09 to 0.95) were found, while only 3 participants (17%) had an acceptable systemic bias of <0.1 °C. CONCLUSION: Group level data showed that the ECTemp™ algorithm had an acceptable systematic bias during prolonged walking exercise in warm ambient conditions, but only 3 out of 18 participants had an acceptable systemic bias. Future studies are needed to improve the accuracy of the algorithm before individual users can rely on their estimated TC during real-world exercise.

Smartwatch measurement of blood oxygen saturation for predicting acute mountain sickness: Diagnostic accuracy and reliability.

Objective: This study aims to assess the accuracy and stability of smartwatches in predicting acute mountain sickness (AMS). Methods: In locations exceeding an altitude of 2500 m, a cohort of 42 subjects had their Lake Louise AMS self-assessment score, blood oxygen saturation (SpO2), heart rate, and perfusion index measured using smartwatches, with the data seamlessly conveyed to the Huawei Cloud. Results: A significant decrease in SpO2 was observed in individuals positive for AMS compared to those negative (p < 0.05), with the mild AMS group exhibiting significantly lower SpO2 levels than the non-AMS group (p < 0.05). Furthermore, SpO2 emerged as a significant, independent predictor of AMS [ß=-0.086, p < 0.01, OR (95% CI) = 0.92 (0.87-0.97)], indicating that each unit increase in SpO2 decreases the probability of AMS occurrence by 8.6%. Conclusion: The Huawei smartwatches have demonstrated efficacy in diagnosing and foretelling AMS at elevations exceeding 4000 m, showcasing significant reliability and high precision in SpO2 measurement.

Assessing the psychobiological demands of high-fidelity training in pre-hospital emergency medicine.

BACKGROUND: Individuals who provide critical emergency care mount rapid psychobiological responses when faced with an incident. These responses are adaptive and ensure resources at time of demand; however, frequent activation with minimal opportunity for recovery can have negative consequences for health and wellbeing. Monitoring individuals in real emergency situations would provide an understanding of their stress responses during the provision of critical care; however, this presents logistical challenges. An alternative is to assess individuals during high-fidelity training scenarios. This is the first comprehensive assessment of psychobiological responding during continuous high-fidelity training in pre-hospital emergency medicine. METHODS: A sample of doctors and paramedics (N = 27) participated during 10 days of training and a weekend of no activities. Training involved the acquisition of human factors, non-technical and surgical skills, and their application in complex high-fidelity scenarios including road-traffic accidents, firearms incidents, and swift water rescue operations. On each day participants reported levels of state, cognitive, and somatic anxiety, and self-confidence following waking and before sleep, and their anticipated (at wake) and experienced (before sleep) demands of the day. Saliva samples were obtained each day for assessment of diurnal cortisol indices and the Cortisol Awakening Response (CAR). Garmin smartwatches were worn throughout for the collection of heart rate and HRV-derived stress. RESULTS: There were significant (p < 0.001) differences across days for state, cognitive, and somatic anxiety; self-confidence; anticipated and experienced demands; aggregated measures of heart rate and HRV-derived stress; levels of cortisol at waking (p = 0.002) and for the CAR (p < 0.001). Measures of psychobiological responding during training were distinct from the weekend and the highest levels of psychobiological responding occurred on days characterised by greater anticipated and experienced demands. DISCUSSION: This high-fidelity training is typical of the day-to-day requirements of emergency services and these observations are representative of functioning during real-life critical care emergencies. Increased responding during times of demand is adaptive; however, frequent and sustained responding increases allostatic load and is a contributor to burnout. As burnout is a significant concern in emergency medicine, this study identifies patterns of responding and recovery that may impact upon longer-term health and wellbeing.

Using a virtual reality game to train biofeedback-based regulation under stress conditions.

Physiological regulation strategies can be effective in reducing anxiety. However, while these strategies are often learned and practised under low-stress conditions, they are more likely to be required under conditions of high stress. We created virtual reality (VR) biofeedback games to both teach participants a breathing technique and then practise that technique under stress. We present two studies: the first provides a proof of concept, demonstrating that participants can apply the breathing technique during stress, with a significant lowering of both respiration rate and increase in heart rate variability (HRV) under stress (p < .001). The second study explicitly evaluated the effectiveness of training by comparing trained and untrained groups. Training was associated with a significantly greater HRV (p = .008) under stress. In within-group comparisons of HRV during stress compared to a baseline stressor presented before training, the trained group showed a significantly greater increase compared to untrained controls (p = .025). Our results show the feasibility and potential effectiveness of VR-based games for biofeedback training under experimentally applied stress. This may offer the opportunity for clinical techniques to more closely reflect the circumstances under which those techniques will be required.

Cognitive control processes and emotion regulation in adolescence: Examining the impact of affective inhibition and heart-rate-variability on emotion regulation dynamics in daily life.

Cognitive control processes likely influence the extent to which adolescents can successfully regulate their emotions. This study examined whether individual differences in affective inhibition and heart rate variability (HRV), as a peripheral index of cognitive control, moderated the association between momentary emotion regulation and negative affect (NA). Ecological Momentary Assessments (EMA) over 14 days were obtained in 235 adolescents (Mage = 13.48 years; 106 females). At each assessment, participants reported their current NA and the extent to which they used cognitive reappraisal and rumination. Moreover, at three time points (approximately 1 year, 6 months, and just before the EMA), affective inhibition was assessed using an affective go/no-go task and HRV was recorded at rest. Results indicate that adolescents with lower affective inhibition reported lower average levels of daily rumination. However, affective inhibition did not moderate the association between either daily cognitive reappraisal or rumination and momentary NA. Consistent with hypotheses, the association between momentary rumination and NA was weaker in adolescents showing higher levels of resting HRV. Overall, findings may underscore the importance of interventions targeting HRV as a malleable factor for enhancing adolescents' affective well-being.

The influence of heart rate on the relationship between pulse transit time and systolic blood pressure.

OBJECTIVE: Pulse transit time (PTT) is a popular indicator of blood pressure (BP) changes. However, the relationship between PTT and BP is somehow individual dependent, resulting in the inaccuracy of PTT-based BP estimation. Confounding factors, e.g., heart rate (HR), of PTT and BP could be the primary cause. In this study we attempt to explore the impact of HR as a window to look at the influence of confounding factors on the relationship between PTT and BP. APPROACH: We investigated the relationship between PTT and systolic BP (SBP) at different HR levels by introducing the heterogeneous treatment effects (HTE) as a quantitative indicator. Compared to the average HR calculated using traditional indicators (e. g. regression coefficient, correlation coefficient), the HTE calculation method can compute the relationship between PTT and SBP at different HR levels, and reduce the influence of confounding factors. MAIN RESULTS: We analyzed the HTE of PTT and SBP of 47 subjects who are resting healthy young people with varying levels of HR. The results showed that the strength of the HTE of PTT and SBP varied with HR, indicating that the strength of the causal relationship between PTT and SBP is subject to HR levels. Whereas the correlation between SBP and PTT was individual dependent; either the strength or the direction of the correlation can vary with HR. We further investigated the group in which PTT and SBP exhibited a negative correlation, and found that about 50% of the subjects showed enhanced strength of HTE in with an increase in HR and the remaining showed the opposite. SIGNIFICANCE: This study means that HR needs to be considered when PTT is used as an indicator of SBP.

Pathways to maternal health inequities: Structural racism, sleep, and physiological stress.

Racial inequities in health are vast and well-documented, particularly regarding maternal and infant health. Sleep health, including but not limited to duration and quality, is central to overall health and well-being. However, research has not adequately addressed how racism embedded in structures and systems, in addition to individual experiences, may affect maternal health by impacting sleep. In this critical review, we aim to 1) synthesize findings, emphasizing collaborative studies within our group, 2) highlight gaps in knowledge, and 3) propose a theoretical framework and methodological approach for moving the field forward. Specifically, we focus on findings and future directions linking perinatal sleep, cardiovascular and immune function, and racial disparities in maternal health. Because too few studies look beyond individual-level determinants of sleep deficiencies among Black Americans, we assert a critical need for research that bridges multiple levels of analysis (e.g., individual, community, society) and provides recommendations for specific health parameters that researchers in this area can target. Although the need to understand and address perinatal health disparities is clear, the goal of identifying multilevel mechanisms underlying how racism in one's environment and daily life may interact to affect health extends far beyond pregnancy research.

Maternal vascular indices and hemodynamic parameters at 36 weeks' gestation in gestational and pre-existing diabetes mellitus.

OBJECTIVE: To compare maternal vascular indices and hemodynamic parameters at 35-37 weeks' gestation in pregnancies complicated by gestational diabetes mellitus (GDM), those with pre-existing diabetes mellitus (DM) and those without GDM or pre-existing DM. METHODS: This was a prospective observational study in women with a singleton pregnancy attending for a routine hospital visit at 35 + 0 to 36 + 6 weeks' gestation. The visit included recording of maternal demographic characteristics and medical history, and measurement of vascular indices and hemodynamic parameters using a non-invasive operator-independent device. These included carotid-to-femoral pulse-wave velocity, augmentation index, cardiac output, stroke volume, central systolic and diastolic blood pressure, total peripheral resistance and heart rate. The values in the GDM and pre-existing DM groups were compared to those in the unaffected group. RESULTS: We examined 6746 women, of whom 396 were excluded because they had chronic hypertension or developed pre-eclampsia or gestational hypertension. The study population of 6350 pregnancies contained 99 (1.6%) with pre-existing Type-I or Type-II DM and 617 (9.7%) that developed GDM, including 261 (42.3%) that were treated with diet alone, 239 (38.7%) treated with metformin alone and 117 (19.0%) treated with insulin with or without metformin. Among women with GDM and those with pre-existing DM, compared to those without GDM or pre-existing DM, there was a higher median cardiac output and heart rate, central systolic and diastolic blood pressure and pulse-wave velocity, but there was no significant difference in stroke volume and total peripheral resistance. There were no significant differences within the GDM group according to treatment type, except for higher heart rate in women treated with metformin alone compared to the group treated with diet alone. CONCLUSION: Women with GDM and those with pre-existing DM have evidence of early vascular disease in the third trimester, and this may contribute to their increased long-term cardiovascular risk. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Social Context in Stress and Autism: Comparing Physiological Profiles Across Two Social Paradigms in Youth with and without Autism Spectrum Disorder.

Background: The social world is often stressful for individuals with autism spectrum disorder (ASD). Research shows youth with ASD demonstrate physiological hyperreactivity to some social stressors (e.g., interaction) but not others (e.g., evaluation); therefore, this study examined diagnosis (ASD or typical development (TD)), social context, perceived anxiety, and physiological responsivity across multiple stress systems; namely, the hypothalamic pituitary adrenal (HPA) axis and autonomic nervous system (ANS). Method: This study examined 244 ten-to-thirteen-year-olds with ASD (N = 140) or TD (N = 104). Physiological responses, measured by salivary cortisol, heart rate (HR), and respiratory sinus arrhythmia (RSA), were assessed before and after a social evaluative threat paradigm (Trier Social Stress Test; TSST) and social interaction (Trier Social Stress Test- Friendly; TSST-F). Mediation models examined the relationships between anxiety, diagnosis, and physiology. Results: Significant three-way interactions were observed for cortisol (p=0.007) and HR (p=0.002), suggesting diagnostic groups respond differently across context and time points. There was no significant interaction for RSA (p=0.149), although ASD youth had significantly lower RSA overall (p=0.038). State and trait anxiety did not mediate the relationship between diagnosis and physiology (all p>0.05). Conclusions: Findings emphasize the critical role of context and a multisystem approach in examination of physiological social stress in youth with ASD. Results provide a foundation to elucidate unique response patterns across physiological systems to more precisely identify those with heightened physiological arousal across social contexts. It is proposed that future identification of subtypes may ultimately inform approaches for enhancing social engagement.

Comparison of Heart Rate Variability Psychological Responses and Performance in Virtual and Real Archery.

BACKGROUND: This study examines the psychophysiological differences between virtual reality (VR) and real archery. It explores whether VR archery induces heart rate (HR), heart rate variability (HRV), and breathing rates similar to those experienced in real archery. Additionally, the study assesses differences in perceived anxiety, difficulty, confidence, rate of perceived exertion (RPE), and shooting performance between the two modalities, providing insights into the efficacy of VR as a training tool for archery. METHODS: Twenty-two (women: 8) individuals aged 20-24 participated in the study. We first recorded individuals' resting HR, HRV, and breathing rates during baseline. Afterward, participants shot 10 real and virtual arrows from 18 m, whereas their HR, HRV, and breathing rate were measured, each lasting 4 min. Performance in VR and real archery was determined separately as the sum of the shots. We performed paired sample t-tests to compare individuals' performance, psychological, and psychophysiological responses recorded during VR and real arrow shooting. Afterward, we compared percentage changes between VR and real archery. RESULTS: Results showed that HR and root mean square of successive differences (RMMSD) were significantly higher during real archery compared to virtual archery. In addition, VR archery led to a greater percentage change in RMSSD compared to real archery. Participants reported greater RPE and perceived difficulty after real archery. Performance was also higher during VR archery than real archery. CONCLUSIONS: Consequently, the results of the present study illustrated that VR, and real archery might lead to different autonomic response patterns in terms of vagal activity.

Evaluating the Effects of Different Cognitive Tasks on Autonomic Nervous System Responses: Implementation of a High-Precision, Low-Cost Complementary Method.

INTRODUCTION: We developed a low-cost, user-friendly complementary research tool to evaluate autonomic nervous system (ANS) activity at varying levels of cognitive workload. This was achieved using visual stimuli as cognitive tasks, administered through a specially designed computer-based test battery. METHODS: To assess sympathetic stress responses, skin conductance response (SCR) was measured, and electrocardiograms (ECG) were recorded to evaluate heart rate variability (HRV), an indicator of cardiac vagal tone. Twenty-five healthy adults participated in the study. SCR and ECG recordings were made during both tonic and phasic phases using a computer-based system designed for visual stimuli. Participants performed a button-pressing task upon seeing the target stimulus, and the relationship between reaction time (RT) and cognitive load was evaluated. RESULTS: Analysis of the data showed higher skin conductance levels (SCLs) during tasks compared to baseline, indicating successful elicitation of sympathetic responses. RTs differed significantly between simple and cognitive tasks, increasing with mental load. Additionally, significant changes in vagally mediated HRV parameters during tasks compared to baseline highlighted the impact of cognitive load on the parasympathetic branch of the ANS, thereby influencing the brain-heart connection. CONCLUSION: Our findings indicate that the developed research tool can successfully induce cognitive load, significantly affecting SCL, RTs, and HRV. This validates the tool's effectiveness in evaluating ANS responses to cognitive tasks.

Racial biases, facial trustworthiness, and resting heart rate variability: unravelling complexities in pain recognition.

The study explores whether racial identity and appearance-based trustworthiness judgments can affect recognition of pain in medical students differing in levels of resting heart rate variability (HRV), a measure of parasympathetic control of the heart. After undergoing HRV assessment, 68 medical students (37 females) participated in a dynamic pain recognition task, viewing video clips of White and Black faces, which differed in perceived trustworthiness based on facial appearance, transitioning from neutral to intense pain expressions. Response time, pain intensity attribution and treatment recommendations were analyzed. Pain was recognized slower and estimated as less intense in Black compared to White faces, leading to a lower likelihood of recommending therapy. Pain recognition was faster for untrustworthy-looking White faces compared to trustworthy ones, while perceived trustworthiness had a minimal impact on the speed of pain recognition in Black faces. However, untrustworthy-looking faces were estimated to express more pain, particularly for Black faces. Notably, these biases were more pronounced in individuals with low, rather than high, resting HRV. Considering that therapeutic decisions mirrored pain intensity attribution, it would be important to increase awareness of these biases during medical training in order to promote equity in future pain assessment and treatment.

Agreement Between Heart Rate Variability - Derived vs. Ventilatory and Lactate Thresholds: A Systematic Review with Meta-Analyses.

BACKGROUND: Determining thresholds by measuring blood lactate levels (lactate thresholds) or gas exchange (ventilatory thresholds) that delineate the different exercise intensity domains is crucial for training prescription. This systematic review with meta-analyses aims to assess the overall validity of the first and second heart rate variability - derived threshold (HRVT1 and HRVT2, respectively) by computing global effect sizes for agreement and correlation between HRVTs and reference - lactate and ventilatory (LT-VTs) - thresholds. Furthermore, this review aims to assess the impact of subjects' characteristics, HRV methods, and study protocols on the agreement and correlation between LT-VTs and HRVTs. METHODS: Systematic computerised searches for studies determining HRVTs during incremental exercise in humans were conducted. The agreements and correlations meta-analyses were conducted using a random-effect model. Causes of heterogeneity were explored by subgroup analysis and meta-regression with subjects' characteristics, incremental exercise protocols, and HRV methods variables. The methodological quality was assessed using QUADAS-2 and STARDHRV tools. The risk of bias was assessed by funnel plots, fail-safe N test, Egger's test of the intercept, and the Begg and Mazumdar rank correlation test. RESULTS: Fifty included studies (1160 subjects) assessed 314 agreements (95 for HRVT1, 219 for HRVT2) and 246 correlations (82 for HRVT1, 164 for HRVT2) between LT-VTs and HRVTs. The standardized mean differences were trivial between HRVT1 and LT1-VT1 (SMD = 0.08, 95% CI -0.04-0.19, n = 22) and between HRVT2 and LT2-VT2 (SMD = -0.06, 95% CI -0.15-0.03, n = 42). The correlations were very strong between HRVT1 and LT1-VT1 (r = 0.85, 95% CI 0.75-0.91, n = 22), and between HRVT2 and LT2-VT2 (r = 0.85, 95% CI 0.80-0.89, n = 41). Moreover, subjects' characteristics, type of ergometer, or initial and incremental workload had no impact on HRVTs determination. CONCLUSION: HRVTs showed trivial differences and very strong correlations with LT-VTs and might thus serve as surrogates. These results emphasize the usefulness of HRVTs as promising, accessible, and cost-effective means for exercise and clinical prescription purposes.

Pilot turning behavior cognitive load analysis in simulated flight.

Background: To identify the cognitive load of different turning tasks in simulated flight, a flight experiment was designed based on real "preliminary screening" training modules for pilots. Methods: Heart Rate Variability (HRV) and flight data were collected during the experiments using a flight simulator and a heart rate sensor bracelet. The turning behaviors in flight were classified into climbing turns, descending turns, and level flight turns. A recognition model for the cognitive load associated with these turning behaviors was developed using machine learning and deep learning algorithms. Results: pnni_20, range_nni, rmssd, sdsd, nni_20, sd1, triangular_index indicators are negatively correlated with different turning load. The LSTM-Attention model excelled in recognizing turning tasks with varying cognitive load, achieving an F1 score of 0.9491. Conclusion: Specific HRV characteristics can be used to analyze cognitive load in different turn-ing tasks, and the LSTM-Attention model can provide references for future studies on the selection characteristics of pilot cognitive load, and offer guidance for pilot training, thus having significant implications for pilot training and flight safety.

Feasibility of Monitoring Heart and Respiratory Rates Using Nonwearable Devices and Consistency of the Measured Parameters: Pilot Feasibility Study.

Background: As Japan is the world's fastest-aging society with a declining population, it is challenging to secure human resources for care providers. Therefore, the Japanese government is promoting digital transformation and the use of nursing care equipment, including nonwearable devices that monitor heart and respiratory rates. However, the feasibility of monitoring heart and respiratory rates with nonwearable devices and the consistency of the rates measured have not been reported. Objective: In this study, we focused on a sheet-type nonwearable device (Safety Sheep Sensor) introduced in many nursing homes. We evaluated the feasibility of monitoring heart rate (HR) and respiratory rate (RR) continuously using nonwearable devices and the consistency of the HR and RR measured. Methods: A sheet-type nonwearable device that measured HR and RR every minute through body vibrations was placed under the mattress of each participant. The participants in study 1 were healthy individuals aged 20-60 years (n=21), while those in study 2 were older adults living in multidwelling houses and required nursing care (n=20). The HR was measured using standard methods by the nurse and using the wearable device (Silmee Bar-type Lite sensor), and RR was measured by the nurse. The primary outcome was the mean difference in HR and RR between nonwearable devices and standard methods. Results: The mean difference in HR was -0.32 (SD 3.12) in study 1 and 0.04 (SD: 3.98) in study 2; both the differences were within the predefined accepted discrepancies (<5 beats/min). The mean difference in RR was -0.98 (SD 3.01) in study 1 and -0.49 (SD 2.40) in study 2; both the differences were within the predefined accepted discrepancies (3 breaths/min). Conclusions: HR and RR measurements obtained using the nonwearable devices and the standard method were similar. Continuous monitoring of vital signs using nonwearable devices can aid in the early detection of abnormal conditions in older people.

International expert consensus statement on physiological interpretation of cardiotocograph (CTG): First revision (2024).

The first international consensus guideline on physiological interpretation of cardiotocograph (CTG) produced by 44 CTG experts from 14 countries was published in 2018. This guideline ensured a paradigm shift from classifying CTG by arbitrarily grouping certain features of the fetal heart rate into different "categories", and then, randomly combining them to arrive at an overall classification of CTG traces into "Normal, Suspicious and Pathological" (or Category I, II and III) to a classification which is based on the understanding of fetal pathophysiology. The guideline recommended the recognition of different types of fetal hypoxia, and the determination of features of fetal compensatory responses as well as decompensation to ongoing hypoxic stress on the CTG trace. Since its first publication in 2018, there have been several scientific publications relating physiological interpretation of CTG, especially relating to features indicative of autonomic instability due to hypoxic stress (i.e., the ZigZag pattern), and of fetal inflammation. Moreover, emerging evidence has suggested improvement in maternal and perinatal outcomes in maternity units which had implemented physiological interpretation of CTG. Therefore, the guideline on Physiological Interpretation of CTG has been revised to incorporate new scientific evidence, and the interpretation table has been expanded to include features of chorioamnionitis and relative utero-placental insufficiency of labour (RUPI-L).