Advanced Stress Management: Integration of Physiological Signals and Personal Characteristics to Prevent and Manage Stress

Advanced Stress Management: Integration of Physiological Signals and Personal Characteristics to Prevent and Manage Stress Wilhelm Daniel Scherz, [email protected] Supervised by: Prof. Dr. Ralf Seepold and Prof. Dr. Juan Antonio Ortega Ramirez The doctoral thesis is submitted to the Department of Computer Languages and Systems of the University of Sevilla in fulfilment of the requirements for the degree of Ph.D. in Software Engineering and Technology. Seville, June 2024 PHD Thesis 2024 Wilhelm Daniel Scherz Page: 2 Title: Advanced stress management: integration of physiological signals and personal characteristics to prevent and manage stress PhD student: Wilhelm Daniel Scherz University: University of Sevilla Supervisor Universidad de Sevilla: Prof. Dr. Juan Antonio Ortega Ramirez Supervisor HTWG Konstanz: Prof Dr. Ralf Seepold End date: June 2024 Keywords: Electrocardiogram, ECG, Biometrics, Stress detection, Heart rate, Trier Social Stress Test Stroop, Correlation Abstract: Stress management is becoming increasingly important in our society. It is evident that stress, whether measured subjectively or physiologically, has a detrimental effect on decision-making abilities and significantly impacts an individual's health and well-being, as well as the private and public economy. While technological advances simplify our daily lives, managing stress is more challenging than ever due to individual perceptions, cultural nuances, and personality traits. The need to respond quickly to workplace challenges, traffic, and the drive to achieve more is making chronic stress more prevalent, underscoring the importance of understanding, measuring, and predicting stress. PHD Thesis 2024 Wilhelm Daniel Scherz Page: 3 In this work, stress is defined as the body's response to a stressor. Stressors can be either short-term or long-term, causing the body to function differently than it should, but also helping it respond to and cope with situations. Common ways of measuring stress include two main approaches: the classic method using questionnaires or direct conversations, and the use of physiological signals. In this research, we used questionnaires and heart rate characteristics to determine baseline stress levels, compared stress with physical activity, and studied the relationship between stress, personality traits, and demographics of the participants. It is important to remember that stress cannot be entirely avoided in our lives. Stress optimizes bodily functions and assists in coping with dangerous or challenging situations. However, it is possible to develop a system that helps us understand and detect stress more efficiently, thereby avoiding dangerous or hazardous situations. This could lead to significant improvements in sectors where errors are costly or can influence health. By doing so, a better understanding, better management, and a reduction of the negative long-term effects of stress can be achieved. Wilhelm Daniel Scherz Chapter: Contents PHD Thesis 2024 Wilhelm Daniel Scherz Page: 4 Contents Contents ........................................................................................................................................................... 4 List of Figures ................................................................................................................................................... 7 List of Tables .................................................................................................................................................... 7 Declaration of Authorship ................................................................................................................................ 9 Linguistic Gender Equality .............................................................................................................................. 10 Special Thanks ................................................................................................................................................ 11 Research Motivation ......................................................................................................................... 13 Research Outline .............................................................................................................................. 18 2.1 Research Question .................................................................................................................................. 18 2.2 Research Objectives ................................................................................................................................ 18 2.3 Success Criteria ....................................................................................................................................... 18 2.4 Work Outline ........................................................................................................................................... 19 Introduction ...................................................................................................................................... 20 3.1 The Definition of Stress ........................................................................................................................... 20 3.2 The History of Stress Starts As A Response ............................................................................................. 21 3.2.1 Stress Response ...................................................................................................................................... 23 3.2.2 Eustress ................................................................................................................................................... 23 3.2.3 The Challenges in Defining Eustress and Distress ................................................................................... 24 3.2.4 Distress .................................................................................................................................................... 25 3.2.5 Wear and Tear......................................................................................................................................... 25 3.2.6 Stress Hormones ..................................................................................................................................... 26 3.2.7 Cortisol Hormone .................................................................................................................................... 26 Stress Measurement Methods .......................................................................................................... 27 4.1 Questionnaire ......................................................................................................................................... 27 4.1.1 Perceived Stress Questionnaire .............................................................................................................. 27 4.1.2 State-Trait Anxiety Inventory .................................................................................................................. 28 4.1.3 Holmes and Rahe Stress Scale................................................................................................................. 28 4.1.4 Life Events and Difficulties Schedule ....................................................................................................... 29 4.2 Biomarkers Analysis ................................................................................................................................ 29 4.2.1 Hormonal Analysis .................................................................................................................................. 30 4.2.2 Physiological Measurement Through Sensor Measurement .................................................................. 31 4.2.3 Heart Rate Variability .............................................................................................................................. 33 4.3 Behaviour Analysis .................................................................................................................................. 33 Chapter: Contents PHD Thesis 2024 Wilhelm Daniel Scherz Page: 5 Data Processing ................................................................................................................................ 35 5.1 Heart Rate Extraction from ECG .............................................................................................................. 35 5.2 Stress Gradient Method .......................................................................................................................... 36 5.3 Heart Rate Variability .............................................................................................................................. 37 5.3.1 Poincaré-Plot ........................................................................................................................................... 37 Experiment and Data Acquisition ...................................................................................................... 40 6.1 Experiment Setup .................................................................................................................................... 41 6.2 Experiment Explanation and Consent Agreement .................................................................................. 41 6.3 Participant Demographics and Criteria ................................................................................................... 42 6.4 Data Obtained from the Experiment using a Driving Simulator ............................................................. 43 6.4.1 Pre-questionnaire ................................................................................................................................... 44 6.4.2 Perceived Stress Questionnaire 20 ......................................................................................................... 45 6.4.3 Revised Eysenck Personality Questionnaire-Short .................................................................................. 45 6.4.4 Post-questionnaire .................................................................................................................................. 45 6.4.5 Heart Rate Monitoring ............................................................................................................................ 46 Selected Research Works .................................................................................................................. 47 7.1 Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device ................................................................................................................................................... 48 7.2 The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress .................................................................................................................................................. 75 7.3 RR interval analysis for the distinction between stress, physical activity and no activity using a portable ECG .............................................................................................................................................................. 109 7.4 Identification of Behavioral Driving Risks from Physiological Stress ..................................................... 116 7.5 Experiment design for Stress data collection while driving in a simulator ........................................... 128 7.6 Can Virtual Reality be used as a significant stressor for studies using ECG .......................................... 139 Additional Research works ............................................................................................................. 150 Conclusions and Future Work ......................................................................................................... 158 9.1 Conclusion ............................................................................................................................................. 158 9.2 Future Works ........................................................................................................................................ 159 Appendix ........................................................................................................................................ 163 10.1 Awards .................................................................................................................................................. 163 10.1.1 Best Paper on the XII Russian-German Conference on Biomedical Engineering (RGC 2016) ............... 163 Chapter: Contents PHD Thesis 2024 Wilhelm Daniel Scherz Page: 6 10.1.2 Finalists in the Germany Colombian Day in Bonn Organised by the BMBF (Federal ministry of Education and Research) 2023 ............................................................................................................................................. 165 10.1.3 DAAD Scholarship for Conferences 2023 .............................................................................................. 166 10.1.4 DAAD Scholarship for Conferences 2024 .............................................................................................. 167 10.2 Research Stay Abroad ........................................................................................................................... 167 10.2.1 The British University in Egypt, Egypt 2023 .......................................................................................... 167 10.2.2 The British University in Egypt, Egypt 2022 .......................................................................................... 167 10.2.3 University of Sevilla and University of Loyola, Spain 2020 ................................................................... 168 10.2.4 Università Politecnica delle Marche, Italy 2017 .................................................................................... 168 10.2.5 Università Politecnica delle Marche, Italy 2016 .................................................................................... 168 10.2.6 Moscow Russia (23.09.2016-02.10.2016) 9 days .................................................................................. 169 10.2.7 STUBA: Slovak University of Technology in Bratislava (Slovakia) .......................................................... 169 10.3 Project Participation ............................................................................................................................. 170 10.4 Teaching and Lab Experience ................................................................................................................ 173 10.5 Supervised Works ................................................................................................................................. 173 10.5.1 Final Bachelor Works ............................................................................................................................ 173 10.5.2 Final Master Thesis Works .................................................................................................................... 174 10.5.3 Team Projects ....................................................................................................................................... 174 10.6 Scientific Publications Inclusive Conference Proceedings .................................................................... 176 10.7 Experiment Protocol ............................................................................................................................. 179 10.8 Pre-Test Questionnaire ......................................................................................................................... 183 10.9 Perceived Stress Questionnaire (PSQ) .................................................................................................. 188 10.10 Personality Traits and Driving Stress Questionnaire ............................................................................. 191 10.11 Post-Test Questionnaire ....................................................................................................................... 198 10.12 Declaration of Informed Consent .......................................................................................................... 201 References ...................................................................................................................................... 206 Closing Acknowledgements ................................................................................................................................ 212 List of Figures PHD Thesis 2024 Wilhelm Daniel Scherz Page: 7 List of Figures Figure 1 Stress as a health problem ...................................................................................................... 15 Figure 2 Fight-or-flight response ........................................................................................................... 22 Figure 3 ECG P, Q, R, S, T segments ....................................................................................................... 32 Figure 4 RR interval in a QRS on a typical ECG ...................................................................................... 33 Figure 5 Poincaré plot with sample data ............................................................................................... 38 Figure 6 Poincaré plot comparison of the results of a Trier test with those of a relaxation test ......... 39 Figure 7 Experiment flowchart .............................................................................................................. 42 Figure 8 Complete experiment data model .......................................................................................... 44 Figure 9 SJR index Electronics ............................................................................................................... 49 Figure 10 Scopus score Electronics ....................................................................................................... 49 Figure 11 Electronics 5 years impact factor JCR .................................................................................... 49 Figure 12 Sensors 2020 Scopus score .................................................................................................... 76 Figure 13 Sensors 2020 Impact Factor (JCR) ......................................................................................... 76 Figure 14 EMBC Ranking in GII-GRIN-SCIE (GGS) Conference Rating .................................................. 110 Figure 15 KES GII-GRIN-SCIE (GGS) Conference Rating ....................................................................... 117 Figure 16 Scopus score Procedia Computer Science ........................................................................... 117 Figure 17 GII-GRIN-SCIE (GGS) Conference Rating KES ....................................................................... 129 Figure 18 Scopus Score 2023 KES ........................................................................................................ 129 Figure 19 GII-GRIN-SCIE (GGS) Conference Rating KES ....................................................................... 140 Figure 20 Scopus Score 2020 KES ........................................................................................................ 140 List of Tables Table 1 Workplace Stress-Related Consequences (Hassard et al., 2018) ............................................. 13 Table 2 Stress quantification questionnaires ........................................................................................ 28 Table 3 JCR Ranks Electronics ................................................................................................................ 49 Table 4 SJR Ranks Electronics ................................................................................................................ 50 Table 5 JCR ranks Sensors 2020 ............................................................................................................ 76 Table 6 Index of the International Conference of the IEEE Engineering in Medicine and Biology Society ............................................................................................................................................................. 110 Table 7 Teaching experience ............................................................................................................... 173 List of Tables PHD Thesis 2024 Wilhelm Daniel Scherz Page: 8 Table 8 Supervised final bachelor thesis ............................................................................................. 173 Table 9 Supervised final master thesis ................................................................................................ 174 Declaration of Authorship | Research Question PHD Thesis 2024 Wilhelm Daniel Scherz Page: 9 Declaration of Authorship Hereby I, Wilhelm Daniel Scherz, born 25th March 1986 in 74564 Crailsheim, Germany, solemnly declare: 1. That I have written my doctoral thesis entitled " Advanced stress management: integration of physiological signals and personal characteristics to prevent and manage stress " at the department of “Lenguajes y Sistemas Informáticos” in the program “30210001 - Ingeniería y Tecnología de software” in the University of Sevilla under the supervision of Prof. Dr. R. Seepold and Juan Antonio Ortega independently and without external assistance and have not used any aids other than those mentioned in the thesis. 2. That I have indicated the adoption of literal quotations from literature and the use of the ideas of other authors in the appropriate places in the thesis. 3. That this thesis has not been submitted in the same form or in a similar form to any other board of examiners. I am aware that a false declaration may have legal consequences. Konstanz, June 2024 Wilhelm Daniel Scherz Digital unterschrieben von Wilhelm Daniel Scherz DN: cn=Wilhelm Daniel Scherz, o=HTWG Konstanz, ou=IN, [email protected], c=DE Datum: 2024.06.28 10:51:53 +02'00' Adobe Acrobat-Version: 2021.007.20099 Research Motivation | Research Question PHD Thesis 2024 Wilhelm Daniel Scherz Page: 16 The previously mentioned expenses caused by stress are the effects of long-term stress. Prolonged exposure to stress can have severe negative consequences. In some cases, it can even produce changes in the structure of the brain (Cardoner et al., 2024) and an inability to respond appropriately to the high mental demands. The short-term effects of stress are not severe and usually do not lead to the degeneration of the body and in opposition they serve a purpose and can even be beneficial by enabling us to survive dangerous situations. A more detailed examination of this topic will be presented in the subsequent section, which will address the effects of stress. The individual consequences and the social burden caused by stress make stress research and detection to an important and necessary topic. With a correct understanding and management of stress it can be considered more as a normal phase of the life that can not only be controlled but also used advantageously, so that long-term problems could be reduced or prevented. Stress questionnaires are a widely used method for measuring stress in psychology. However, these questionnaires rely on subjective self-reporting, which implies that the individual taking the test must perceive that a stressful situation is occurring. The most common types of stress questionnaires will be described in the following chapter. The main disadvantages of using questionnaires as method to detect stress are: • Limited Self-Awareness: Individuals may not recognize their own stress or may be unwilling to admit it. Questionnaires rely on self-reporting, which can be inaccurate. • Lack of Real-Time Feedback: Questionnaires do not capture stress fluctuations in real-time. They provide a snapshot of a person's state at the time of completion. • Language Dependence: The reliability of questionnaires can be compromised by cultural interpretations and language limitations, affecting the accuracy of the responses. • Evaluation Expertise Required: Analysing and interpreting questionnaires effectively often requires a trained mental health professional. Some of the main challenges of the stress research are the individual perception of stress. To be more precise, two individuals find themselves in the same stressful situation but will evaluate and perceive Research Motivation | Research Question PHD Thesis 2024 Wilhelm Daniel Scherz Page: 17 the situation differently, meaning each of them will feel differently stressed although the physical responses are similar. In addition to the aforementioned factors, it is also important to consider the individual's personality traits and cultural background. These factors can influence the way in which a person perceives a situation and the level of stress they experience. This is why there is a need in a systematic methodology that could detect and estimate objectively stress and characteristics like personality traits or cultural context which have to be taken in consideration for the a more precise estimation of stress. A system like this would help to reduce significantly financial costs caused by stress, as well as to reduce probable mistakes and improve the life quality of people. The following chapter will present the research question and the objectives of the study. Research Outline | Research Question PHD Thesis 2024 Wilhelm Daniel Scherz Page: 18 Research Outline 2.1 Research Question The topic of stress research is very broad, with many nuances that have significant implications and require deeper understanding. Nonetheless, we will focus our work on the following research question: Can physiological data, such as heart rate collected from mobile devices, particularly chest straps be used to measure stress? What personal characteristics, such as personality traits and culture, should be considered to refine stress estimation? In order to respond adequately to the research question, a series of research objectives need to be considered. 2.2 Research Objectives The results obtained from this research should serve as a solid foundation for future works and research that aim to combine stress research with other fields in order to improve safety and wellbeing of people who may suffer from stress. To achieve this objective, the following steps are required: - Observe what the difference between no stress and stress is by analysing physiological data; - Analyse the relationship between personality traits and stress and identify which personality traits have a stronger relationship with stress; - Plan and carry out a study that investigate the relationships between stress, personality traits and driving characteristics; - Expand the system to other use cases. 2.3 Success Criteria This research can be considered successfully completed when the relationship between stress and heart rate, as well as the impact of personality traits on the strength of stress, are thoroughly addressed. To achieve this, several scientific studies have been conducted to observe the activities of individuals under stress and in relaxed conditions, and to analyse the relationship between personality traits and stress levels. The results should show if there is a difference between the strength of stress Research Outline | Work Outline PHD Thesis 2024 Wilhelm Daniel Scherz Page: 19 experienced by individuals with different personality traits and how does this affect the behaviour while being under stress and in case of no stress. 2.4 Work Outline This dissertation is organised into the following chapters: - Introduction: I present the general terms and definitions that are related to stress. - Stress Measurement Methods: I present the methodologies that can be employed for the measurement of stress - Experiment and Data Acquisition: I present the main study carried out to obtain the data used for the subsequent analysis. - Selected Research Work: I present the selected publications that were submitted to journals or core conferences. - Additional Research work: I present additional publications that provide additional details about the research. - Conclusions and Future Work: I discuss what avenues can be further explored for this research, as well as what the concluding remarks of the work are. At the end of the thesis there is an appendix where all the questionnaires used, the curriculum vitae and any other relevant material can be found. Introduction | The Definition of Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 20 Introduction This chapter defines the term of stress, as well as provides a brief history of research in this field, introduces basic concepts and methods, and outlines the limitations of these concepts. In addition, the motivation for the work is established and the importance of the topic and the impact of stress are explained. Therefore, the definition of stress is given in the following subchapter. 3.1 The Definition of Stress The term “stress” has multiple meanings that vary depending on the context and the discipline in which it is used. In linguistics, stress refers to the emphasis placed on a word or syllable in a sentence or word. In engineering and physics, stress is a force that can alter the shape of an object. In the context of people and health, stress is a state of great worry caused by a difficult situation or something that causes this condition3. This further section will provide a more detailed explanation. When discussing stress detection and estimation in humans, it is important to consider the context of health and individuals. However, it is a challenging task. Worry is a subjective evaluation that varies from person to person. What may be less concerning for one individual may be more concerning for another. This emphasises the difficulty in objectively measuring stress, as each person experiences and perceives stress differently. This thesis addresses only the stress experienced by individuals. Other forms of stress are not discussed. To understand the origins and development of stress, we need to look at how it works and what it means to us. 3 Oxford Dictionary: https://www.oxfordlearnersdictionaries.com/definition/english/stress_1 Introduction | The History of Stress Starts As A Response PHD Thesis 2024 Wilhelm Daniel Scherz Page: 21 3.2 The History of Stress Starts As A Response When we consider the origin of stress, it can be identified as a physical response or mechanism that occurs as a result of dangerous, demanding or harmful events. This response involves the reorganisation of certain biological functions and characteristics that can help to cope with the imminent threat. This response is commonly referred to as the fight or flight response. The common process by which this occurs is shown in Figure 2. The typical procedure for the fight or flight response is as follows: a threat or harmful situation appears and needs to be perceived. The perceived threat is then processed and evaluated by the brain, which typically decides between two possible outcomes based on this evaluation. • Outcome number one is the flight response. In this case, we choose to confront the threat and fight against it. • Outcome number two is the flight response. In this case, we attempt to run away from the threat. It is important to note that there is a third outcome that is closely related to the fight-or-flight response: playing dead, also known as tonic immobility. This is the only viable option once it has been realised that it is not possible to fight or flee. A classic example of this is the opossum, but this behaviour has also been observed in humans in extreme situations such as rape (Fragkaki et al., 2016; Morabito et al., 2024). Figure 2 illustrates some of the physical effects and physiological functions that are altered by the fight- or-flight response. These can be categorised into two groups: those that aid in a successful fight-or- flight response and those that are unnecessary and only serve as a waste of resources in a threatening context. As an example, the fight-or-flight response can be triggered by the attack of a wild animal, such as a sabretooth tiger. The body responds to the thread by increasing the heart rate, which enables to support the muscles with higher blood flow and more oxygen, which is required for fighting or fleeing. In these situations, the digestion of food is not important for fighting or fleeing from a threat. Introduction | The History of Stress Starts As A Response PHD Thesis 2024 Wilhelm Daniel Scherz Page: 22 Figure 2 Fight-or-flight response As previously stated, stress has evolved as a crucial survival mechanism in response to dangerous situations. Over time, the nature of these threats has undergone partial transformation, with the risk of being attacked by a wild animal now virtually non-existent. However, situations requiring rapid responses remain a fundamental aspect of our daily lives. In prehistoric times, stress was a survival instinct for both animals and humans. However, in modern times, stress is no longer necessary for survival, but rather for coping with the demands of daily life. Although stress still enables fast reactions to threats, it is now mostly employed to handle the demands of modern society and life. Consequently, in modern society, people are frequently or constantly under stress. A common but inaccurate understanding of stress is to describe it as the peak of a dramatic event. A more accurate definition of stress could be any situation that requires a swift and immediate reaction for a specific period of time. In this work, these situations, which may require a faster response, will be referred to as stressors. There are many known stressors and some of them are used for research purposes. Some very popular methods are the Trier tests (Allen et al., 2017; Kirschbaum et al., 1993), the Stroop Colour and Word Test (Stroop, 1935) and the mathematical operation test (Ashcraft & Kirk, 2001). Introduction | The History of Stress Starts As A Response PHD Thesis 2024 Wilhelm Daniel Scherz Page: 23 The phenomenon of stress can be effectively illustrated by the analogy of wear and tear on a machine. If a machine is subjected to constant overload, it will inevitably deteriorate and lose its initial effectiveness and precision, due to the accumulated wear and tear. This is analogous to the deterioration of the human body under similar conditions. For our body, short moments of stress are not a major issue or problem, but constant and continuous exposure to stress can overwhelm our body, wear it out and cause some physiological and psychological problems that will lead to a worsening of the quality of life and shortening of life expectancy. The literature classifies stress into two categories: positive and useful, and destructive, oxidative and damaging. This differentiation mainly depends on the length of time and the amount of stress to which the person is exposed. The concept of stress was first defined by Hans Selye in a number of different works (Selye, 1978). The main idea of his definition was that in our daily environment, we are always exposed to two types of stress. The first is eustress, which is understood as positive stress, and the second is distress, which is meant to be negative stress. 3.2.1 Stress Response This chapter reviews the assessment of distress, the roles of situational factors and personality in generating distress, and its psychological significance, including clinical implications. Distress is typically defined as unpleasant subjective stress responses such as anxiety and depression. It may be measured using a variety of general and context-linked scales. States of distress reflect psychobiological, cognitive, and social influences, but should be understood as the outcome of dynamic self-regulation as the person confronts external threats and pressures. Individuals do differ considerably in their susceptibility to distress. Traits such as neuroticism, dispositional anxiety, and cognitive self-awareness increase vulnerability, whereas traits such as hardiness, grit, and emotional intelligence support resilience. Distress is associated with abnormalities in information processing, including attentional impairment and cognitive bias. Distress is also a key symptom in a range of emotional disorders. 3.2.2 Eustress The term eustress is frequently employed to describe positive stress that benefits the body and is less deleterious than distress. In accordance with the views of Selye, eustress may be regarded as a desired effect in certain circumstances (Selye, 1978). Introduction | The History of Stress Starts As A Response PHD Thesis 2024 Wilhelm Daniel Scherz Page: 24 The literature provides a vague definition of eustress, with most work in the field of stress focusing on the concept of stress in general. The majority of works on stress has focused on the negative side of stress without specifying it, making the distinction between stress and eustress difficult and unclear. One common definition of eustress is “stress that lacks negative effects”. Another definition of eustress is “the ideal amount of stress that can be handled well by the body without causing harm”. Eustress can be defined in two ways: firstly, as a positive response of the body towards a stressor, meaning a positive bodily reaction; and secondly, as a positive cognitive response to a stressor, meaning that if a person perceives the stressor as good, they will feel good and have positive feelings. Consequently, eustress may be defined as either a positive response to a stressor or as a positive interpretation of a stressor. This is observable in a work environment where deadlines are manageable and other manageable stressors are present (Hargrove et al., 2015). 3.2.3 The Challenges in Defining Eustress and Distress The current interpretation of stress allows for the simultaneous presence of eustress and distress (Nelson & Simmons, 2003). According to Frankenhause, this depends on the environment/context and can occur individually or in combination but depend of the environment (Lundberg & Frankenhaeuser, 1980). The main factors that differentiate whether stress is perceived as eustress or distress, according to Frankenhause, do not depend on the nature of the stressor, but rather on the individual interpretation and emotional impact of the stressor. This means that the same person can perceive the same situation with the same demands and stressors at different points in time as either eustress or distress, depending on their individual emotions and personal interpretation of the situation at that moment. Furthermore, the individual may experience both positive and negative reactions. For instance, deadlines can be perceived as positive or negative, depending on the circumstances. If the individual has sufficient time and resources to complete the task within the remaining timeframe, they may view it as a positive challenge that will facilitate their growth. Conversely, if they are in a negative mood and perceive the task as negative, the entire situation may be perceived as negative and stressful. Introduction | The History of Stress Starts As A Response PHD Thesis 2024 Wilhelm Daniel Scherz Page: 25 3.2.4 Distress As previously stated, stress is most commonly defined as a negative experience, in accordance with the definition proposed by Hans Selye. This definition is also in line with that proposed by health professionals, who define distress as a state or situation in which the individual is unable to adapt to or cope effectively with the situation. In contrast to eustress, distress is associated with a range of health problems and issues, including cardiovascular illness (Mei et al., 2015; Zaffalon Júnior et al., 2018), changes in the brain structure (Cardoner et al., 2024), metabolic problems (Masschelin et al., 2019; Zaffalon Júnior et al., 2018), etc. Because of the steady growth in the field of stress research and the weak or imprecise definitions of the terms stress, distress and eustress, and for simplicity and ease of understanding, we will not differentiate between the terms. For this reason, in this work, we will limit our discussion to the concept of stress. Additionally, as previously stated, the distinction between eustress and distress becomes less significant if they are not managed correctly and handled in a timely manner, as both can lead to similar negative outcomes. 3.2.5 Wear and Tear The wear and tear model, also known as the accumulation model, suggests that stress is cumulative. This means that the daily struggles, minor stressors and major life events we experience contribute to deteriorating physical and mental well-being. As a result, if stress is not managed, this constant exposure can lead to anxiety, depression, burnout and other health problems. We can illustrate it like this: think of stress as stones in a backpack. Each stress that you experience adds another stone. If you do nothing to lighten the load (by managing stress), the weight of the stones can eventually become too heavy to carry. Another illustrative example is the concept of "wear and tear" on a piece of equipment. If a machine is subjected to excessive workloads, it will inevitably begin to deteriorate, resulting in a loss of effectiveness and precision compared to its original state when it was newly installed and wellmaintained. This is due to the accumulation of wear and tear over time. Stress Measurement Methods | Biomarkers Analysis PHD Thesis 2024 Wilhelm Daniel Scherz Page: 32 sodium pump works (Malmivuo & Plonsey, 1995). During stressful situations, more energy is needed and the heart has an important role to play in meeting this extra demand. Normally, the heartbeat of a healthy heart exhibits a certain degree of variability. However, under stress, this variability is driven by the stress response. The polarisation or depolarisation of the heart can be quantified using an electrocardiogram, which allows for the observation of variations in heartbeats and the different phases of a heartbeat, as depicted in the resulting graph (see Figure 3). 4.2.2.2 Electrocardiogram The electrocardiogram (ECG) is a widely used non-invasive diagnostic technique. It comprises sensing leads placed on the skin. The ECG measures the electrical activity of the heart by detecting the potential difference between the leads. By placing the electrodes in the proper places around the chest, we can measure the electrical activity of the heart. It is not uncommon for this measurement to indicate the presence of interference caused by contractions of other muscles situated in close proximity to the heart. Movement of the electrodes can also result in the generation of artefacts in the signals. Furthermore, the power grid or other electrical machines can introduce noise into the signals. Electrocardiography (ECG) can be employed for the diagnosis of cardiac abnormalities. In certain instances, the ECG can indicate the area of the heart that is affected and the type of abnormality. The placement and number of electrodes employed can provide varying perspectives of the heart. ECGs are employed in the diagnosis of cardiac abnormalities. The most commonly utilized leads are the 3- lead, 5-lead (for continuous monitoring) and 12-lead (for detailed diagnosis) (Drew et al., 2004). Figure 3 shows a heartbeats and each heartbeat can be divided in to different segments depending of what is happening with the heart muscle. Figure 3 ECG P, Q, R, S, T segments Stress Measurement Methods | Behaviour Analysis PHD Thesis 2024 Wilhelm Daniel Scherz Page: 33 4.2.3 Heart Rate Variability Under normal circumstances, the intervals between successive heart beats are not identical and show slight changes. This variability enables the cardiovascular system to adjust to sudden changes resulting from physical or physiological demands. By dynamically adjusting the heart rate, the cardiovascular system can maintain homeostasis, the body's state of equilibrium. Heart rate variability (HRV) is defined as the differences between consecutive heartbeats (McCraty & Shaffer, 2015). In order to calculate the difference between two heartbeats, it is important to define when the interval of a heartbeat begins and ends. As previously mentioned, a heartbeat can be described by the QRS complex, which is measured using an electrocardiogram (ECG). In this study, the R peak of the QRS complex is used as the starting point for the interval, with the subsequent R peak marking the end. This results in the RR interval, defined as the time between two consecutive heartbeats. Figure 4 illustrates a typical QRS complex and the RR interval. Another term for this interval is the interbeat interval (IBI). Figure 4 RR interval in a QRS on a typical ECG 4.3 Behaviour Analysis The principal idea of behavioural analysis is to look for repetitive patterns of behavioural patterns and to analyse changes in behaviour, reactions and/or expressions in response to specific situations. Typically, a baseline is established, and significant alterations are categorised as stress or other psychological patterns. An example of this is stress detection via social media (Ding et al., 2023). The paper proposed a continuous assessment of stress using social media. Data was collected from 69 senior high school students (grades 10, 11 and 12) between August 26, 2012 and August 25, 2013 on Tencent Weibo (a microblogging social media platform). A total of 8,543 posts were collected. The relevant events were observed and classified into three intensity levels, ranging from strong (3) to Stress Measurement Methods | Behaviour Analysis PHD Thesis 2024 Wilhelm Daniel Scherz Page: 34 weak (1). The authors considered events such as graduation, final exams, and midterms to be highly stressful, while contests and competitions were ranked as 2 and 1, respectively. Notifications for exams or the start of school were also considered stressful. It should be noted that this scale does not reflect an individual's actual perceived stress level, as the authors presumed that all students had a similar perception of stress for the same events. The emotional states were extracted from the posts. The authors developed a system to assess the frequency of posts and their content, detecting the amount of stress perceived by students in a week with a maximum accuracy of 86.32%. This approach is similar to that employed by other researchers (Wang et al., 2020), where 90 % accuracy was obtained. Other example for this category is detecting stress by analysing the interaction with the keyboard. Users pressed the keys harder and had more contact with the mouse than usual when under stress. (Hernandez et al., 2014). A contrasting strategy was employed by Slavich et al., who utilised speech analysis in order to assess stress levels. Their approach was predicated upon the pervasiveness of digital devices in contemporary society, which afforded the possibility of real-time monitoring of stress. However, a significant limitation of this methodology is the lack of comprehensive investigation into the indicators that can be extracted from voice. Additionally, ethical and security concerns pertaining to data privacy are not sufficiently addressed (Slavich et al., 2019). Data Processing | Heart Rate Extraction from ECG PHD Thesis 2024 Wilhelm Daniel Scherz Page: 35 Data Processing This chapter provides a brief overview of the calculations and methods employed. In the preceding chapter 5.1, a detailed description of the calculation of the RR intervals is provided. The RR intervals serve as the foundation for all subsequent calculations. Afterwards, the gradient method, which can be used to analyse the direction of stress change, will be discussed. Finally, the Poincaré plot, which is useful for estimating stress levels, will be presented. 5.1 Heart Rate Extraction from ECG If the source of the data is an ECG, an extraction and calculation of the HR and RR intervals are required. To accomplish this, the following steps should be followed: - Detecting the first peak of an ECG (1) - Detecting the second peak of the ECG - Calculating the interval duration between two detected peaks (RR interval) (2) - Calculating the heart rate on base of the RR interval (3) Following calculations show the steps that are required to obtain the required data. The initial stage of the process is the determination of the maximum value of the data set. This value represents the peak of the "R" wave. (1) 𝐸𝐸𝐸𝐸𝐸𝐸𝑖𝑖−1<𝐸𝐸𝐸𝐸𝐸𝐸𝑖𝑖>𝐸𝐸𝐸𝐸𝐸𝐸𝑖𝑖+1 ( 1 ) Subsequently, two consecutive R-peaks are compared and the interval between them is calculated. This is the RR interval (2). 𝑅𝑅𝑅𝑅=𝑅𝑅𝑖𝑖−1−𝑅𝑅𝑖𝑖 ( 2 ) To calculate the heart rate from the RR interval, the following formula can be employed (3). It is crucial to note that the results obtained will be the number of heartbeats per minute, but this will vary with each heartbeat. This is the instantaneous heart rate. Therefore, this is not an averaged value. Data Processing | Stress Gradient Method PHD Thesis 2024 Wilhelm Daniel Scherz Page: 36 𝐻𝐻𝑅𝑅=1𝑚𝑚𝑖𝑖𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚 𝑅𝑅𝑅𝑅𝑠𝑠𝑚𝑚𝑠𝑠 =60𝑠𝑠𝑚𝑚𝑠𝑠 𝑅𝑅𝑅𝑅𝑠𝑠𝑚𝑚𝑠𝑠 ( 3 ) The mean heart rate can be calculated following the completion of the aforementioned step (4). 𝐻𝐻𝑅𝑅(𝑖𝑖)=1 𝑖𝑖�𝐻𝐻𝑅𝑅𝑗𝑗 𝑖𝑖 𝑗𝑗=𝑚𝑚 ( 4 ) 5.2 Stress Gradient Method In a subsequent publication, we present the stress gradient method. This model enables the estimation of stress variation. A model of this nature could be employed to estimate the change in stress and to forecast future stress or drowsiness. The difference between two heartbeats is calculated by subtracting two consecutive heartbeats. This indicates the magnitude of the variation between the two heartbeats (5). Successive Differences = {RR𝑖𝑖−RR𝑖𝑖−1} ( 5 ) In order to calculate the variation of the heartbeat over a specified time interval for a windowing algorithm, for example, the following formula may be employed (6). Mean of Squared Differences =1 𝑁𝑁−1�(RR𝑖𝑖−RR𝑖𝑖−1)2 𝑁𝑁−1 𝑖𝑖=1 ( 6 ) The root mean square of successive differences (RMSSD) is calculated according to the following formula (7). RMSSD =�Mean of Squared Differences ( 7 ) Data Processing | Heart Rate Variability PHD Thesis 2024 Wilhelm Daniel Scherz Page: 37 The objective of this calculation is to determine the gradient of the root mean square of successive differences (RMSSD) with respect to time (8). ∇𝑓𝑓=∇𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅(𝑡𝑡)=𝜕𝜕𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝜕𝜕𝑡𝑡 = 𝑑𝑑𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝑑𝑑𝑡𝑡 ( 8 ) The value m is the stress index that is calculated out of the signal. As faster this value changes more stressed the person is. This value is later also used to calculate a risk index based on stress (9). 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅2=𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅1+𝑑𝑑𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝑑𝑑𝑡𝑡 (𝑡𝑡2−𝑡𝑡1)+⋯,⇒ 𝑑𝑑𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝑑𝑑𝑡𝑡 ≈𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅2−𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅1 𝑡𝑡2−𝑡𝑡1=𝑚𝑚 ( 9 ) 5.3 Heart Rate Variability The capacity of living organisms to alter the heartbeat interval (RR interval) is referred to as the heart rate variability (HRV). 5.3.1 Poincaré-Plot This method analyses heart rate variability (HRV) by correlating the R-R interval with the preceding R- R interval (Mazhar B. Tayel & Eslam I. AlSaba, 2015). The R-R interval, which represents the time between two consecutive QRS complexes on an ECG, will be denoted by a specific symbol 𝑥𝑥𝑚𝑚. (10) Similarly, the preceding R-R interval will be denoted by another symbol 𝑥𝑥𝑚𝑚−1 (11). 𝑥𝑥0={𝑅𝑅𝑅𝑅0,𝑅𝑅𝑅𝑅1,𝑅𝑅𝑅𝑅2,𝑅𝑅𝑅𝑅3, … 𝑅𝑅𝑅𝑅𝑚𝑚} ( 10 ) 𝑥𝑥1= {𝑅𝑅𝑅𝑅1,𝑅𝑅𝑅𝑅2,𝑅𝑅𝑅𝑅3,𝑅𝑅𝑅𝑅4, … 𝑅𝑅𝑅𝑅𝑚𝑚+1} ( 11 ) Figure 5 shows an example of a set of RR intervals and their visual representation by means of a Poincaré-plot. Data Processing | Heart Rate Variability PHD Thesis 2024 Wilhelm Daniel Scherz Page: 38 Figure 5 Poincaré plot with sample data The standard deviation 𝜎𝜎1 and 𝜎𝜎2 are the most important characteristics of the graph (See Figure 6). The standard deviation and variance 𝑣𝑣𝑣𝑣𝑣𝑣(𝑥𝑥), are calculated as follows: 𝜎𝜎1= �𝑣𝑣𝑣𝑣𝑣𝑣(𝑥𝑥1)→ 𝑥𝑥1= 𝑥𝑥𝑚𝑚−𝑥𝑥𝑚𝑚+1 √2 ( 12 ) 𝜎𝜎2= �𝑣𝑣𝑣𝑣𝑣𝑣(𝑥𝑥2)→𝑥𝑥2= 𝑥𝑥𝑚𝑚+𝑥𝑥𝑚𝑚+1 √2 ( 13 ) This means that 𝑥𝑥1and 𝑥𝑥2 are the rotation of 𝑥𝑥𝑚𝑚and 𝑥𝑥𝑚𝑚+1 by 𝜋𝜋4 (14) �𝑥𝑥1 𝑥𝑥2�=�cos 𝜋𝜋4−sin 𝜋𝜋4 sin 𝜋𝜋4cos 𝜋𝜋4��𝑥𝑥𝑚𝑚 𝑥𝑥𝑚𝑚+1� ( 14 ) The inclination can be calculated using the following formula (15): 𝜌𝜌(𝑥𝑥,𝑦𝑦)= cos 𝛼𝛼 ( 15 ) Data Processing | Heart Rate Variability PHD Thesis 2024 Wilhelm Daniel Scherz Page: 39 Figure 6 presents the results of a Trier test. Each dot, or plus symbol, represents a pair of RR intervals that are consecutive. Each colour represents a different phase of the experiment, with blue representing the preparation to start the Trier test, red representing the interview test, and green representing the relaxation phase. It can be observed that the variations between each consecutive RR interval pair are less when the subject is less stressed and greater when the subject is more stressed. Figure 6 Poincaré plot comparison of the results of a Trier test with those of a relaxation test Experiment and Data Acquisition | Heart Rate Variability PHD Thesis 2024 Wilhelm Daniel Scherz Page: 40 Experiment and Data Acquisition This chapter is devoted to the description and explanation of the experiment. t will provide a comprehensive examination of the conducted experiments, including a detailed description and a flowchart of the experiment. Using a driving simulator as a stressor has several advantages. Firstly, it is safer and easier to convince people to participate in an experiment, conducted on a driving simulator, compared to one that requires them driving a real car. Secondly, it is easier to control the environment and create a replicable environment compared to a real driving scenario. When drivers are confronted with considerable traffic demands, such as heavy traffic, aggressive drivers, or challenging meteorological conditions, stress may be a substantial factor that affects their behaviour. This perception of insufficient control or inability to cope with the situation leads to a decline in driving performance, resulting in more mistakes behind the wheel, an increase in traffic violations, and ultimately, a risk to the driver himself and road safety in general. Common stressors include time pressure, poor road conditions, and even a general dislike for driving. To investigate the relationship between stress, personality traits, and cultural factors, this experiment has been designed to generate a wide set of variables. The objective is to create a large, replicable dataset that can easily be repeated in other locations to accumulate a more extensive dataset. So far, three experiments have been conducted in different countries: Germany, Spain, and Egypt. These new datasets aim to address a critical challenge in stress research: the lack of extensive data that includes a broad range of variables. This comprehensive data will enable the investigation of relationships between stress and various factors, ultimately leading to a deeper understanding of stress. In our research we propose two hypotheses (Scherz et al., 2024): • The first hypothesis suggests a significant relationship between personality traits and driving stress. It aims to investigate whether personality traits have a notable influence on the experienced stress while driving. Experiment and Data Acquisition | Experiment Setup PHD Thesis 2024 Wilhelm Daniel Scherz Page: 41 • The second hypothesis states that cultural differences between countries (e.g., Spain and Germany) influence the degree to which personality traits affect driving stress. The aim of this hypothesis is to investigate the potential influence of cultural differences on the correlation between driving stress and personality traits. It is suggested that the impact of each personality trait on driving stress may vary across different cultures. The experiment collected data from a total of N=109 participants, including 37 participants from Germany, 59 from Spain, and 15 from Egypt. However, due to issues such as missing data, file corruption, or problems encountered during recording, some datasets had to be discarded. 6.1 Experiment Setup The experiment is divided into four sections, each of which is designed to collect a different type of data. The estimated average duration of the experiment is 35 minutes. A flowchart illustrating the sequence of steps for conducting the experiment is visible in Figure 7. The experiment protocol is provided in the appendix (see Appendix). 6.2 Experiment Explanation and Consent Agreement After recruiting volunteers, we carefully explained the experimental procedure, including a brief overview of the questionnaires and sensor placement. The location of the sensors was clearly indicated. It was explained that the experiment commenced with an introductory questionnaire, which was followed by a five-minute initial phase. Subsequently, the participant was instructed to drive in a realistic manner for 25 minutes. The initial phase had an exact duration (25 minutes of driving), followed by a final questionnaire. Participants only received written consent after they had received an explanation of the procedure, as well as all the steps involved in the experiment, and had voluntarily agreed to take part in the experiment. Should the participant have expressed a lack of safety or disagreement with the written consent and the use of their data, the experiment was terminated. Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 48 7.1 Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device Overview The study examines the relationship between stress, driving safety, and personality traits. It points out that chronic stress is harmful and focuses on the use of wearable sensors to analyse stress in drivers. The paper specifically analyses stress in a selected group of individuals from both Spain and Germany. The individuals were also categorised depending of their personality into one of the three personality traits (neuroticism, extroversion, psychoticism). Context This work was the result of a collaboration with Prof. Dr. Victor Corcoba from the University of Oviedo. As a follow-up activity, a second study was organised and executed in Spain and Germany two years after his research stay. A total of 81 participants were examined, and 71 datasets were deemed usable. A year later, a third study was conducted in Egypt. The further experiments were made possible through active participation in international projects, including the IBH Living Lab Active and Assisted Living, Smart Sleep and the PPP Programme for Project-Related Personnel Exchange with The British University in Egypt (BUE). Journal Information Given the work's focus on healthcare and wellbeing, the special issue “IoT for Healthcare and Wellbeing: Trends, Challenges, and Applications, 2nd Edition” of the journal “Electronics” was chosen for the publication of the work. This journal is indexed by Clarivate in the Journal Impact Factor (JCR) with a current impact factor of 2.6 in a Q2 according to JCR4(Table 3). According to the Scimago Journal & Country Rank (SJR), the journal is indexed as a Q2 (Table 4, Figure 9). The Figure 10, Figure 115, and Table 3 show additional scoring. 4 Accessed 21.06.2024 https://jcr.clarivate.com/jcr-jp/journal-profile?journal=ELECTRONICSSWITZ&year=2023&fromPage=%2Fjcr%2Fhome 5Accessed 21.06.2024 Source: https://www.mdpi.com/journal/electronics/stats Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 49 Figure 11 Electronics 5 years impact factor JCR Table 3 JCR Ranks Electronics JCR COMPUTER SCIENCE, INFORMATION SYSTEMS ENGINEERING, ELECTRICAL & ELECTRONIC PHYSICS, APPLIED Year JIF RANK JIF QUARTILE JIF RANK JIF QUARTILE JIF RANK JIF QUARTILE 2023 115/249 Q2 157/352 Q2 81/179 Q2 2022 99/158 Q3 131/275 Q2 72/160 Q2 2021 100/164 Q3 139/276 Q3 82/161 Q3 2020 93/161 Q3 145/273 Q3 88/160 Q3 2019 N/A N/A 125/266 Q2 N/A N/A Figure 9 SJR index Electronics Figure 10 Scopus score Electronics Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 50 Table 4 SJR Ranks Electronics SJR Computer Networks and Communicatio ns Control and Systems Engineering Electrical and Electronic Engineering Hardware and Architecture Signal Processing Year Quartiles Quartiles Quartiles Quartiles Quartiles 2023 Q2 Q2 Q2 Q2 Q2 2022 Q2 Q2 Q2 Q2 Q2 2021 Q2 Q2 Q2 Q2 Q2 2020 Q2 Q2 Q2 Q3 Q3 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 51 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 52 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 53 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 54 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 55 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 56 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 57 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 64 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 65 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 66 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 67 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 68 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 69 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 70 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 71 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 72 Selected Research Works | Analysis of the Relationship between Personality Traits and Driving Stress Using a Non-Intrusive Wearable Device PHD Thesis 2024 Wilhelm Daniel Scherz Page: 73 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 80 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 81 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 82 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 83 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 84 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 85 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 86 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 87 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 88 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 89 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 96 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 97 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 98 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 99 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 100 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 101 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 102 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 103 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 104 Selected Research Works | The Effects of the Driver’s Mental State and Passenger Compartment Conditions on Driving Performance and Driving Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 105 Selected Research Works | RR interval analysis for the distinction between stress, physical activity and no activity using a portable ECG PHD Thesis 2024 Wilhelm Daniel Scherz Page: 112 Selected Research Works | RR interval analysis for the distinction between stress, physical activity and no activity using a portable ECG PHD Thesis 2024 Wilhelm Daniel Scherz Page: 113 Selected Research Works | RR interval analysis for the distinction between stress, physical activity and no activity using a portable ECG PHD Thesis 2024 Wilhelm Daniel Scherz Page: 114 Selected Research Works | RR interval analysis for the distinction between stress, physical activity and no activity using a portable ECG PHD Thesis 2024 Wilhelm Daniel Scherz Page: 115 Selected Research Works | Identification of Behavioral Driving Risks from Physiological Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 116 7.4 Identification of Behavioral Driving Risks from Physiological Stress Accepted the 04.06.2024 Overview The results of studies carried out in Spain (University of Oviedo), Germany (HTWG Konstanz) and Egypt (British University in Egypt) have led to the formulation of an alternative approach based on the early detection and mitigation of stress-related driving behaviour and risk assessment. The use of wearable devices and vehicle sensors is seen as a potential avenue for real-time monitoring of risky driving behaviour, which would allow the establishment of new assessment methods and the creation of a risk index based on stress and driving behaviour. The study presented in this paper presents a new approach to risk assessment that combines subjective and physiological measurements based on a diverse dataset derived from real-world driving scenarios. Context This work and this new approach are the result of a collaboration with Dr. Dennis Grewe, who was an intern professor at the HTWG Konstanz until 31.05.2024. Using his experience from other projects in the field of vehicle sensors, a new approach was discussed that combined the load data and the vehicle data. This collaboration led to the idea of creating a risk score based on both load and vehicle data. Journal information / Conference Information The focus of this work is risk assessment using physiological measurements and data obtained from the vehicle. This topic fits very well in the fits very well in the scope of the broad spectrum of intelligent systems especially in the general topics of interest Intelligent Engineering Systems, Knowledge-Based Systems, Expert Systems, Cognitive Systems. The International Conference on Knowledge-Based and Intelligent Information & Engineering Systems (KES) is one of the largest conferences in this area. Papers will be published in Elsevier's open access journal Procedia Computer Science, available on ScienceDirect and submitted for indexing/abstracting in CPCi (ISI Conferences and part of Web of Science), Engineering Index and Scopus. Selected Research Works | Identification of Behavioral Driving Risks from Physiological Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 117 The conference is ranked 'B' in the CORE11 conference ranking system (See GII-GRIN-SCIE12 in Figure 15). The papers of the conference are published in the journal Procedia Computer Science and have a Scopus CiteScore13 of 4.5. They are classified as belonging to the field of General Computer Science and are ranked 71/232. Figure 16 show the Scopus index and score of 4.5. Figure 16 Scopus score Procedia Computer Science 11 Accessed 08.06.2024 https://portal.core.edu.au/conf-ranks/1113/ 12 Accessed 08.06.2024 https://scie.lcc.uma.es/ratingSearch.jsf 13 Accessed 08.06.2024 https://www.scopus.com/sourceid/19700182801#tabs=0 Figure 15 KES GII-GRIN-SCIE (GGS) Conference Rating Selected Research Works | Identification of Behavioral Driving Risks from Physiological Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 118 Selected Research Works | Identification of Behavioral Driving Risks from Physiological Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 119 Selected Research Works | Identification of Behavioral Driving Risks from Physiological Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 120 Selected Research Works | Identification of Behavioral Driving Risks from Physiological Stress PHD Thesis 2024 Wilhelm Daniel Scherz Page: 121 Selected Research Works | Experiment design for Stress data collection while driving in a simulator PHD Thesis 2024 Wilhelm Daniel Scherz Page: 128 7.5 Experiment design for Stress data collection while driving in a simulator Overview The aims of this study were to investigate the impact of perceived stress on traffic and road safety, with a specific focus on identifying the relationship between stress and driving. To achieve this, a study was designed to generate and collect data relevant to stress. The Stress Perceived Questionnaire (PSQ) was used to assess perceived stress levels during driving simulations, while the Emotional Profile Questionnaire (EPQR) was employed to determine the personality types of the participants. By categorising the participants based on their emotional and personality traits, we gained insights into the influence of these factors on driving performance and road safety. Additionally, we continuously monitored each participant's heart rate (HR) using wearable devices, which were convenient, non-intrusive, and portable. This allowed us to assess their stress levels in real-time. Context As the experiment became more important to obtain more data to evaluate the relationship between stress and driving, we decided to describe the experiment in the form of a publication. Under the coordination of Prof. Dr. Seepold, the driving simulator was adapted to the needs of the experiment and the sensors to obtain physiological data were validated. This design was also previously shared with our partners in various universities. Journal Information / Conference Information The objective of this publication was to collect data and describe the experiment in a manner that would ensure its replicability. The data obtained can subsequently be used to study stress while driving, with the support of physiological measurements and data obtained from the vehicle. The work is well-suited to the field of intelligent systems, particularly in the domains of intelligent engineering systems, knowledge-based systems, expert systems, and cognitive systems. The KES Selected Research Works | Experiment design for Stress data collection while driving in a simulator PHD Thesis 2024 Wilhelm Daniel Scherz Page: 129 conference is one of the largest in this field. The papers will be published in Elsevier's open access journal Procedia Computer Science, which is available on ScienceDirect and has been submitted for indexing/abstracting in CPCi (ISI Conferences and part of Web of Science), Engineering Index, and Scopus. The conference is ranked 'B' in the CORE14 conference ranking system. Figure 17 sows a screenshot of the sore according to GII-GRIN-SCIE15. The paper is published in “Procedia Computer Science” and has a Scopus CiteScore16 of 4.5 Science and has a the rang number 71/232 (see Figure 18). 14 Accessed 08.06.2024 https://portal.core.edu.au/conf-ranks/1113/ 15 Accessed 08.06.2024 https://scie.lcc.uma.es/ratingSearch.jsf 16 Accessed 08.06.2024 https://www.scopus.com/sourceid/19700182801#tabs=0 Figure 18 Scopus Score 2023 KES Figure 17 GII-GRIN-SCIE (GGS) Conference Rating KES Selected Research Works | Experiment design for Stress data collection while driving in a simulator PHD Thesis 2024 Wilhelm Daniel Scherz Page: 130 Selected Research Works | Experiment design for Stress data collection while driving in a simulator PHD Thesis 2024 Wilhelm Daniel Scherz Page: 131 Selected Research Works | Experiment design for Stress data collection while driving in a simulator PHD Thesis 2024 Wilhelm Daniel Scherz Page: 132 Selected Research Works | Experiment design for Stress data collection while driving in a simulator PHD Thesis 2024 Wilhelm Daniel Scherz Page: 133 Selected Research Works | Experiment design for Stress data collection while driving in a simulator PHD Thesis 2024 Wilhelm Daniel Scherz Page: 134 Selected Research Works | Experiment design for Stress data collection while driving in a simulator PHD Thesis 2024 Wilhelm Daniel Scherz Page: 135 Selected Research Works | Experiment design for Stress data collection while driving in a simulator PHD Thesis 2024 Wilhelm Daniel Scherz Page: 136 Selected Research Works | Experiment design for Stress data collection while driving in a simulator PHD Thesis 2024 Wilhelm Daniel Scherz Page: 137 Selected Research Works | Can Virtual Reality be used as a significant stressor for studies using ECG PHD Thesis 2024 Wilhelm Daniel Scherz Page: 144 Selected Research Works | Can Virtual Reality be used as a significant stressor for studies using ECG PHD Thesis 2024 Wilhelm Daniel Scherz Page: 145 Selected Research Works | Can Virtual Reality be used as a significant stressor for studies using ECG PHD Thesis 2024 Wilhelm Daniel Scherz Page: 146 Selected Research Works | Can Virtual Reality be used as a significant stressor for studies using ECG PHD Thesis 2024 Wilhelm Daniel Scherz Page: 147 Selected Research Works | Can Virtual Reality be used as a significant stressor for studies using ECG PHD Thesis 2024 Wilhelm Daniel Scherz Page: 148 Selected Research Works | Can Virtual Reality be used as a significant stressor for studies using ECG PHD Thesis 2024 Wilhelm Daniel Scherz Page: 149 Additional Research works | PHD Thesis 2024 Wilhelm Daniel Scherz Page: 150 Additional Research works The following paper is a selection of the additional publications that were written while the research on the topic was being conducted. The selected paper is the one that was awarded as the best paper at the beginning of the research. Additional Research works | PHD Thesis 2024 Wilhelm Daniel Scherz Page: 151 Additional Research works | PHD Thesis 2024 Wilhelm Daniel Scherz Page: 152 Additional Research works | PHD Thesis 2024 Wilhelm Daniel Scherz Page: 153