Relevant Physiological Indicators for Assessing Workload in Conditionally Automated Driving, Through Three-Class Classification and Regression

In future conditionally automated driving, drivers may be asked to take over control of the car while it is driving autonomously. Performing a non-driving-related task could degrade their takeover performance, which could be detected by continuous assessment of drivers' mental load. In this regard, three physiological signals from 80 subjects were collected during 1 h of conditionally automated driving in a simulator. Participants were asked to perform a non-driving cognitive task (N-back) for 90 s, 15 times during driving. The modality and difficulty of the task were experimentally manipulated. The experiment yielded a dataset of drivers' physiological indicators during the task sequences, which was used to predict drivers' workload. This was done by classifying task difficulty (three classes) and regressing participants' reported level of subjective workload after each task (on a 0–20 scale). Classification of task modality was also studied. For each task, the effect of sensor fusion and task performance were studied. The implemented pipeline consisted of a repeated cross validation approach with grid search applied to three machine learning algorithms. The results showed that three different levels of mental load could be classified with a f1-score of 0.713 using the skin conductance and respiration signals as inputs of a random forest classifier. The best regression model predicted the subjective level of workload with a mean absolute error of 3.195 using the three signals. The accuracy of the model increased with participants' task performance. However, classification of task modality (visual or auditory) was not successful. Some physiological indicators such as estimates of respiratory sinus arrhythmia, respiratory amplitude, and temporal indices of heart rate variability were found to be relevant measures of mental workload. Their use should be preferred for ongoing assessment of driver workload in automated driving.

Anthropometric Determinants of Respiratory Sinus Arrhythmia in Children

Background: The study was conducted to investigate the implications of anthropometry in school-aged children on the degree of respiratory sinus arrhythmia observed in clinical settings. Methods: In a cohort study, 626 healthy children (52% male) aged 10.8 ± 0.5 years attending primary school in a single town underwent a 12-lead electrocardiogram coupled with measurements of height, weight and blood pressure. Indices of respiratory sinus arrhythmia (pvRSA, RMSSD, RMSSDc) were derived from semi-automatic measurements of RR intervals. Height, weight, BMI, blood pressure as well as waist and hip circumferences were compared between subjects with rhythmic heart rate and respiratory sinus arrhythmia, and correlations between indices of sinus arrhythmia and anthropometry were investigated. Results: Respiratory sinus arrhythmia was recognized in 43% of the participants. Subjects with sinus arrhythmia had lower heart rate (p < 0.001), weight (p = 0.009), BMI (p = 0.005) and systolic (p = 0.018) and diastolic (p = 0.004) blood pressure. There were important inverse correlations of heart rate and indices of sinus arrhythmia (r = −0.52 for pvRSA and r = −0.58 for RMSSD), but not the anthropometry. Conclusion: Lower prevalence of respiratory sinus arrhythmia among children with overweight and obesity is a result of higher resting heart rate observed in this population.

Post craniotomy and electrocardiographic monitoring

Background: Post craniotomy management mainly emphasizes monitoring complications that occur. Close supervision and monitoring are needed in post craniotomy patients, especially in the first 48 hours so that the patient is placed in the intensive care unit (ICU). Various studies have identified various complications that arise from mild complications to severe complications, namely the death of patients after craniotomy, so that hemodynamic monitoring tool are needed. Electrocardiography is one of the hemodynamic monitoring tools in the intensive care room which is very useful in monitoring heart rhythm abnormalities in post-craniotomy patients.Methods: This descriptive study was conducted on 30 respondents post craniotomy and were treated in the Intensive Care Unit (ICU) for 1-3 days of treatment. An electrocardiographic monitoring analysis was performed on 30 respondents, then confirmed by examination of blood electrolytes and blood gas analysis.Results: In this study 90% of respondents experienced electrocardiographic rhythm abnormalities, 50% sinus arrhythmia, 33.3% sinus tachycardia, 6.7% sinus bardycardia. The results of electrolyte examination 18 respondents experienced electrolyte balance disorders where 4 respondents experienced hyponatremia, 7 respondents experienced hypernatremia+hyperchloremia, 1 respondent experienced hyponatremia+hypochloremia, 5 respondents experienced hyperchloremia and 1 respondent experienced hypokalemia. There are 7 respondents experiencing acid-base balance disorders.Conclusions: in this study showed that most of the patients after craniotomy had heart rhythm abnormalities. The most common arrhythmia is sinus arrhythmia. The pathological conditions that accompany these rhythm disturbances are mostly caused by electrolyte balance disorders, acid-base balance disorders or a combination of the two disorders.

Vagal flexibility to negative emotions moderates the relations between environmental risk and adjustment problems in childhood

Neurobiological and social-contextual influences shape children’s adjustment, yet limited biopsychosocial studies have integrated temporal features when modeling physiological regulation of emotion. This study explored whether a common underlying pattern of non-linear change in respiratory sinus arrhythmia (RSA) across emotional scenarios characterized 4–6 year-old children’s parasympathetic reactivity (N = 180). Additionally, we tested whether dynamic RSA reactivity was an index of neurobiological susceptibility or a diathesis in the association between socioeconomic status, authoritarian parenting, and the development of externalizing problems (EP) and internalizing problems over two years. There was a shared RSA pattern across all emotions, characterized by more initial RSA suppression and a subsequent return toward baseline, which we call vagal flexibility (VF). VF interacted with parenting to predict EP. More authoritarian parenting predicted increased EP two years later only when VF was low; conversely, when VF was very high, authoritarian mothers reported that their children had fewer EP. Altogether, children’s patterns of dynamic RSA change to negative emotions can be characterized by a higher order factor, and the nature by which VF contributes to EP depends on maternal socialization practices, with low VF augmenting and high VF buffering children against the effects of authoritarian parenting.

Evaluation of the first-night effect of polysomnographic recording on cardiac autonomic activity in children with autism spectrum disorder

Introduction. The first night effect (FNE) is the tendency to have lower than usual sleep quality and quantity during the first polysomnography (PSG) recording, which alters sleep architecture. The FNE occurs in autism spectrum disorder (ASD), with studies suggesting that cardiac autonomic dysregulation is altered in patients with this illness. Objective. To determine whether the FNE influences the autonomic activity of ASD and typically developing (TD) children. Method. Two PSGs were recorded in 13 ASD and 13 TD children. The FNE was evaluated with eight sleep variables and autonomic activity through respiratory sinus arrhythmia (RSA) and low frequency (LF). Statistical analyses included intra- and inter-subject comparisons. Results. The FNE was present in both groups and affected more sleep variables in the ASD group. There were no significant differences between both recordings in RSA and LF. Inter-subject comparison showed significant differences in certain sleep variables, mainly during the first night. A comparison of RSA and LF between N2 and N3 stages and REM sleep showed that the TD group had significant differences in both measures whereas the ASD group only did so in the LF the first night. Discussion and conclusion. The influence of the FNE on the quantitative characteristics of sleep is corroborated in ASD and TD children, but not in RSA or LF. When the activity of the RSA and LF between sleep stages was considered, a different pattern was observed between the two PSG recordings.

Child maltreatment severity and sleep variability predict mother–infant RSA coregulation

Regulatory processes underlie mother-infant interactions and may be disrupted in adverse caregiving environments. Child maltreatment and sleep variability may reflect high-risk caregiving, but it is unknown whether they confer vulnerability for poorer mother–infant parasympathetic coordination. The aim of this study was to examine mother–infant coregulation of respiratory sinus arrhythmia (RSA) in relation to child maltreatment severity and night-to-night sleep variability in 47 low-income mother–infant dyads. Maternal and infant sleep was assessed with actigraphy and daily diaries for 7 nights followed by a mother–infant still-face procedure during which RSA was measured. Higher maltreatment severity was associated with weakened concordance in RSA coregulation related to the coupling of higher mother RSA with lower infant RSA, suggesting greater infant distress and lower maternal support. In addition, higher infant sleep variability was associated with infants’ lower mean RSA and concordance in lagged RSA coregulation such that lower maternal RSA predicted lower infant RSA across the still-face procedure, suggesting interrelated distress. The findings indicate that adverse caregiving environments differentially impact regulatory patterns in mother–infant dyads, which may inform modifiable health-risk behaviors as targets for future intervention.