Comparative assessment of drivers' stress induced by autonomous and manual driving with heart rate variability parameters and machine learning analysis of electrodermal activity

12openopenZontone, P; Affanni, A; Bernardini, R; Brisinda, D; Del Linz, L; Formaggia, F; Minen, D; Minen, M; Savorgnan, C; Piras, A; Rinaldo, R; Fenici, RZontone, P; Affanni, A; Bernardini, R; Brisinda, D; Del Linz, L; Formaggia, F; Minen, D; Minen, M; Savorgnan, C; Piras, A; Rinaldo, R; Fenici,

Carbohydrate Metabolism in Bacteria: Alternative Specificities in ADP-Glucose Pyrophosphorylases Open Novel Metabolic Scenarios and Biotechnological Tools

We explored the ability of ADP-glucose pyrophosphorylase (ADP-Glc PPase) from different bacteria to use glucosamine (GlcN) metabolites as a substrate or allosteric effectors. The enzyme from the actinobacteria Kocuria rhizophila exhibited marked and distinctive sensitivity to allosteric activation by GlcN-6P when producing ADP-Glc from glucose-1-phosphate (Glc-1P) and ATP. This behavior is also seen in the enzyme from Rhodococcus spp., the only one known so far to portray this activation. GlcN-6P had a more modest effect on the enzyme from other Actinobacteria (Streptomyces coelicolor), Firmicutes (Ruminococcus albus), and Proteobacteria (Agrobacterium tumefaciens) groups. In addition, we studied the catalytic capacity of ADP-Glc PPases from the different sources using GlcN-1P as a substrate when assayed in the presence of their respective allosteric activators. In all cases, the catalytic efficiency of Glc-1P was 1–2 orders of magnitude higher than GlcN-1P, except for the unregulated heterotetrameric protein (GlgC/GgD) from Geobacillus stearothermophilus. The Glc-1P substrate preference is explained using a model of ADP-Glc PPase from A. tumefaciens based on the crystallographic structure of the enzyme from potato tuber. The substrate-binding domain localizes near the N-terminal of an α-helix, which has a partial positive charge, thus favoring the interaction with a hydroxyl rather than a charged primary amine group. Results support the scenario where the ability of ADP-Glc PPases to use GlcN-1P as an alternative occurred during evolution despite the enzyme being selected to use Glc-1P and ATP for α-glucans synthesis. As an associated consequence in such a process, certain bacteria could have improved their ability to metabolize GlcN. The work also provides insights in designing molecular tools for producing oligo and polysaccharides with amino moieties

The progression of hemophilic arthropathy: The role of biomarkers

Background: Hemophilia A and B are X-linked congenital bleeding disorders characterized by recurrent hemarthroses leading to specific changes in the synovium and cartilage, which finally result in the destruction of the joint: this process is called hemophilic arthropathy (HA). This review highlights the most prominent molecular biomarkers found in the literature to discuss their potential use in the clinical practice to monitor bleeding, to assess the progression of the HA and the effectiveness of treatments. Methods: A review of the literature was performed on PubMed and Embase, from 3 to 7 August 2020. Study selection and data extraction were achieved independently by two authors and the following inclusion criteria were determined a priori: English language, available full text and articles published in peer-reviewed journal. In addition, further articles were identified by checking the bibliography of relevant articles and searching for the studies cited in all the articles examined. Results: Eligible studies obtained at the end of the search and screen process were seventy-three (73). Conclusions: Despite the surge of interest in the clinical use of biomarkers, current literature underlines the lack of their standardization and their potential use in the clinical practice preserving the role of physical examination and imaging in early diagnosis

Motion artifact removal in stress sensors used in driver in motion simulators

The effectiveness of electrodermal activity measurements as an indicator of driver stress, can be significantly impaired by motion artifacts, which can trigger false alarms. In this study, motion artifact in driving simulator experiments are adaptively filtered by using the steering wheel signal as the reference variable. The results demonstrate that adaptive removal of motion artifact can be usefully applied to driving simulators

An MPC approach to the design of motion cueing algorithms for small size driving simulators

Driving simulators are widely used in different applications: driver training, vehicle development, and medical studies. To fully exploit the potential of such devices, it is crucial to develop motion control strategies that generate realistic driving feelings. This has to be achieved while keeping the platform within its limited operation space. Such strategies are called motion cueing algorithms. In this paper a particular implementation of a motion cueing algorithm is described, based on Model Predictive Control technique. A distinctive feature of such approach is that it exploits a detailed model of the human vestibular system, and consequently differs from standard motion cueing strategies based on washout filters. The algorithm has been evaluated experimentally on a small-size, innovative platform, by performing tests with professional drivers. Results show that the MPC-based motion cueing algorithm allows to effectively handle the platform working area and to devise simple and intuitive tuning procedures

Simultaneous real-time assessment of sportive pilots’ stress and performance related to vehicle behaviour, during racing with the DIM professional simulator

Abstract book of EH

Car Driver's Sympathetic Reaction Detection through Electrodermal Activity and Electrocardiogram Measurements

Objective: in this paper we propose a system to detect a subject's sympathetic reaction, which is related to unexpected or challenging events during a car drive. Methods: we use the Electrocardiogram (ECG) signal and the Skin Potential Response (SPR) signal, which has several advantages with respect to other Electrodermal (EDA) signals. We record one SPR signal for each hand, and use an algorithm that, selecting the smoother signal, is able to remove motion artifacts. We extract statistical features from the ECG and SPR signals in order to classify signal segments and identify the presence or absence of emotional events via a Supervised Learning Algorithm. The experiments were carried out in a company which specializes in driving simulator equipment, using a motorized platform and a driving simulator. Different subjects were tested with this setup, with different challenging events happening on predetermined locations on the track. Results: we obtain an Accuracy as high as 79.10% for signal blocks and as high as 91.27% for events. Conclusion: results demonstrate the good performance of the presented system in detecting sympathetic reactions, and the effectiveness of the motion artifact removal procedure. Significance: our work demonstrates the possibility to classify the emotional state of the driver, using the ECG and EDA signals and a slightly invasive setup. In particular, the proposed use of SPR and of the motion artifact removal procedure are crucial for the effectiveness of the system

Assisted / autonomous vs. human driving assessment on the DiM driving simulator using objective / subjective characterization.

The present work represents a qualitative investigation of a methodology, based on Driving Simulator session, which could give interesting indications to the vehicle development teams for autonomous and assisted driving about the efficiency/comfortability of the driving intelligence in realistic highway driving scenarios. To prove the methodology, we have preliminarily performed a test with 13 participants. The number is still not statistically significative, and the results of the present work are to be intended for a) investigation and tuning of the methodology and b) for the researchers to understand if, applying signal processing developed in previous works and given a bigger number of participants, the approach could scientifically provide innovative and quantitative indexes for classifying autonomous driving algorithms

Clinical validation of a novel wearable system for real-time telemetric transmission of transient changes of cardiac autonomic modulation induced by psychophysiological and physical stress

Background: Although clinical assessment of cardiac autonomic modulation (CAM) usually relies on off-line heart rate variability analysis (HRVa), measured under stationary conditions according to guidelines, there is a growing interest, in sports medicine and psychophysiology, for the reliable evaluation of acute changes of CAM occurring under real-world dynamics (i.e. acute stress induced by competitions or critical situations). The aim of this study was to test, with a standardized clinical protocol inducing enhancement of sympathetic/vagal modulation, the reliability of a novel system for continuous monitoring and telemetric transmission of transient CAM changes (Vi- BioBox), provided by real-time calculation of time-variant HRV parameters and Skin Potential Response (SPR). Methods: All measurements were performed in the laboratory for clinical electrophysiology. The Vi-BioBox system (Vi-grade, Udine) consists of a wearable wireless mini-recording device connected to a textile electrode garment (Nuubo, Spain) and hands electrodes. 3 ECG and 2 SPR signal are continuously recorded (1 KHz sampling-rate) and streamed in real-time to Wintax4 (Magneti-Marelli) data logging for real-time calculation and monitoring of spectral HRV parameters and of the Root Mean Square value of two SPR signals (SPRRMS) with a proprietary custom software (Vi-BioSoft). 10 healthy volunteers (mean age 32.4±16.8 y, 50% males) underwent a 5-steps protocol: 1) 10-minutes baseline supine; 2) 10-minutes Head-up tilting 70° (HUTT); 3) 10-minutes supine recovery); 4) 20-minutes mental stress ("Mensa" preliminary Tests); 5) exercise-test at bicycle-ergometer. 12- lead ECG was continuously recorded also with Mortara Surveyor/X-Scribe and Time-variant HRV parameters were also calculated off-line with Kubios (3.0.2) software. Statistical analysis was performed with SPSS 21. Results: The quality of the Vi-BioBox signals was optimal for reproducible real-time calculation and monitoring of time-variant HRV parameters. Baseline SPRRMS activity ranged between 0.01 and 0.8 mV, with wide interindividual variability. A significant (p<0.05) increment (up to 2.6 mV) was induced by HUTT, but not by physical exercise. SPRRMS and LF/HF had similar trend along test session. Good agreement was found between HRV parameters calculated in real-time, their off-line recalculation with Kubios software and those obtained from Mortara telemetry. Conclusion: Real-time monitoring of time-variant spectral HRV parameters and of SPRRMS was reliable and reproducible. SPRRMS is an independent sensitive marker of sympathetic activation, which anticipates increments of VLF, LF and is useful to interpret CAM underlying of LF/HF changes. Real-time monitoring of CAM may be useful to improve the mechanistic understanding of acute psychophysiological stress-reactions, dysautonomic syncope, arrhythmic events initiation and for telemedicine (i.e. continuous remote monitoring of CAM in patients with heart failure)

An MPC approach to the design of motion cueing algorithms for driving simulators

Driving simulators play an important role in the development of new vehicles and advanced driver assistance devices. In fact, on the one hand, having a human driver on a driving simulator allows automotive OEMs to bridge the gap between virtual prototyping and on-road testing during the vehicle development phase. On the other hand, novel driver assistance systems (such as advanced accident avoidance systems) can be safely tested by having the driver operating the vehicle in a virtual, highly realistic environment, while being exposed to hazardous situations. In both applications, it is crucial to faithfully reproduce in the simulator the drivers perception of forces acting on the vehicle and its acceleration. The strategy used to operate the simulator platform within its limited working space to provide the driver with the most realistic perception goes under the name of motion cueing. In this paper we describe a novel approach to motion cueing design that is based on Model Predictive Control techniques. Two features characterize the algorithm, namely, the use of a detailed model of the human vestibular system and a predictive strategy based on the availability of a virtual driver. Differently from classical schemes based on washout filters, such features allows a better implementation of tilt coordination and to handle more efficiently the platform limits