Test Persons Research Articles

Visual assessment of movement quality: a study on intra- and interrater reliability of a multi-segmental single leg squat test

BackgroundThe Single Leg Squat test (SLS) is a common tool used in clinical examination to set and evaluate rehabilitation goals, but there is not one established SLS test used in the clinic. Based on previous scientific findings on the reliability of the SLS test and with a methodological rigorous setup, the aim of the present study was to investigate the intra- and interrater reliability of a standardised multi-segmental SLS test.MethodsWe performed a study of measurement properties to investigate the intra- and interrater reliability of a standardised multi-segmental SLS test including the assessment of the foot, knee, pelvis, and trunk. Novice and experienced physiotherapists rated 65 video recorded SLS tests from 34 test persons. We followed the Quality Appraisal for Reliability Studies checklist.ResultsRegardless of the raters experience, the interrater reliability varied between “moderate” for the knee variable (ĸ = 0.41, 95% CI 0.10–0.72) and “almost perfect” for the foot (ĸ = 1.00, 95% CI 1.00–1.00). The intrarater reliability varied between “slight” (pelvic variable; ĸ = 0.17, 95% CI -0.22-0.55) to “almost perfect” (foot variable; ĸ = 1.00, 95% CI 1.00–1.00; trunk variable; ĸ = 0.82, 95% CI 0.66–0.97). A generalised kappa coefficient including the values from all raters and segments reached “moderate” interrater reliability (ĸ = 0.52, 95% CI 0.43–0.61), the corresponding value for the intrarater reliability reached “almost perfect” (ĸ = 0.82, 95% CI 0.77–0.86).ConclusionsThe present study shows a “moderate” interrater reliability and an “almost perfect” intrarater reliability for the variable all segments regardless of the raters experience. Thus, we conclude that the proposed standardised multi-segmental SLS test is reliable enough to be used in an active population.

Психофизиологическое состояние операторов при ротации рабочих недель «день — вечер»

Modern industrial society is characterized by the growing threat of accidents and catastrophes caused by the human factor. This is a very broad concept. It includes many aspects of human interaction with the technogenic environment, including the probability of operator errors caused by the instability of his psychophysiological state, which is incompatible with the strict technological regulations. At the shift work, this instability is often caused by disturbances in the physiological rhythm of sleep — wakefulness followed by a biological conflict between the forced activity and certain phases of the natural circadian rhythm in the cognitive structures of the brain. This situation known for thy night shift modes can also occur in the evening shift modes. However, the influence of the «day — evening» mode on the psychophysiological state of the shift workers is studied to a lesser extent. The objective of this study was to identify the dynamics of the psychophysiological state of the employees of a certain «model» collective of the paint and varnish shop of the automobile plant, working in the shift mode «5 days — 2 days off — 5 evenings». Test persons were tested immediately after the 1st, 3rd and 5th shifts using a questionnaire describing their self-assessment ranked in points according to four categories (scales). Mathematical analysis of the results revealed a weak trend towards a decrease in the psychological indicators during the daytime work week, but a strong and statistically significant decrease in the evening shifts in relation to the daytime. Thus, the investigated rotational mode of work causes an increasing deterioration in the employee state in the evening shifts, which creates a risk of the impact of the psychogenic human factor on the occupational safety.

The Target-Step-Test (TST) to Evaluate Locomotory Differentiation Ability – Evaluation of the Test and Development of Norm Values for Healthy People

Abstract Introduction There is need of a clinical assessment measuring locomotory differentiation ability. Objective The Target-Step-Test (TST) for evaluating the locomotory differentiation ability should be checked for its reliability in the context of practical application. Furthermore, it is necessary to define a standard value range. In addition, an examination of the exercise attempts should enable a statement to be made about the adequate test execution. Materials and Methods 208 healthy adults between 18 and 45 years were asked to perform the TST twice. The test procedures of 205 test persons could be evaluated. The individual experiments and target steps were photo documented. The 4 directions of movement included stepping forward with the right and left leg and stepping to the side with the right and left leg. Each direction contains 3 exercise steps with open eyes and one target step with closed eyes. The difference to the target line was rounded up or down to 5 mm by the raters. Results For the inter-rater and intra-rater reliability as well as the test-retest reliability high intraclass correlation coefficients (ICCs) and corrected kappa values could be calculated. 90 % of the measurements performed are within the range of −4.85 to 5 cm of the target line. The testing of the measured value repetition shows no differences between 2nd and 3rd step with open eyes. Therefore, it should be sufficient to perform 2 exercise steps with open eyes before the decisive target step with closed eyes. Conclusions The TST is reliable regarding inter-rater, intra-rater and test-retest reliability. The standard value range for healthy adults is set to±5 cm distance from the target line. Regarding the test procedure, it is sufficient to execute the target step with closed eyes after practicing twice with open eyes. The Target-Step-Test is reliable and can easily be carried out in daily routine to measure locomotory differentiation ability as a step movement.

Impaired neck motor control in chronic whiplash and tension-type headache.

The purpose of this study is twofold, first to present a new method based on head laser tracking designed to measure head or hand movements and second to further investigate if patients suffering from chronic whiplash or tension-type headache have impaired motor control of neck muscles. A new laser tracking instrument was designed to measure the ability of a test person to track a reference point moving on the wall by a laser fixed to the forehead or held in the hand. The reference point to be tracked moves in runs of a circle or a square at three different speeds 10, 20, or 30cm/s. We used a 1×1×1m setup geometry to provide head movements well below pain release. Groups of 22 patients diagnosed with chronic whiplash-associated disorder grade 2, 19 patients diagnosed with chronic tension-type headache, and 37 control persons were compared. A small but highly significant dyscoordination of head movements was observed in both patient groups and in whiplash also of the hand. Our study presents a new method based on laser tracking for precision quantitative measurements of head or hand movements during standardized conditions. The results confirm that motor control of head movements is impaired in both chronic whiplash and tension-type headache, and in whiplash also of the hand. This suggests involvement of the central nervous system in the pathology of these diseases.

Diagnostic biomarkers in tear fluid: from sampling to preanalytical processing

Tear fluid is receiving growing attention as a source for novel diagnostic biomarkers. Multiple techniques are available for its collection and impact the composition of acquired samples. We sought to provide a direct comparison of two collection methods with regard to implementation, acceptance, and impact on sample composition. Tear fluid was collected from fifteen healthy volunteers with capillary tubes and Schirmer strips and analyzed for total protein and IgG concentrations. Sampling parameters and perception by test persons were compared. The use of capillary tubes was more convenient for the participants while causing more effort for the collector. Tear flow rates as well as the relative and absolute amount of IgG were higher when Schirmer strips were used. Consecutive collections with Schirmer strips significantly influenced tear flow rates, IgG, and protein concentrations. A moderate correlation was observed between tear flow rates and IgG concentrations for both methods. Samples collected with both methods can be analyzed by isoelectric focusing, a potential diagnostic application in the field of neurology. The specific advantages and limitations of tear fluid sampling with either capillary tubes or Schirmer strips demonstrate the need for a thorough investigation of collection methods with regard to the application of interest.

Prediction model for the analysis of the haptic perception of textiles

In order to stand out from the competition, the quality of a product as subjectively perceived by the customer is becoming increasingly important. If one wants to meet the comprehensive customer requirements, it is no longer sufficient today to develop a product that focuses only on the functional aspects, but it must also fulfil the sensory requirements at the same time. In this paper, a systematic approach is described that first describes the objectification of customer language for describing the textile haptics of automotive interior materials (11 headliners and 15 seat materials). For this purpose, ten textile-specific descriptors were developed in an expert panel. The descriptors used and the measurement of the human-haptic system are summarized in 4 main groups: 1. warmth/cold sensation, 2. friction properties, 3. deformation, 4. surface/topography. Furthermore, the human-tactile parameters (pressure, speed) that humans exert when touching textile surfaces were determined. The human-sensory product evaluation of the textiles was carried out with 116 test persons. Comparative statistical analyses of the technical parameters (e.g. roughness, friction coefficient, wetting index, deformation) and the human characteristics made it possible to create a prognosis model for determining the quality perception of textile car interior materials.

Duality Between Coronavirus Transmission and Air-Based Macroscopic Molecular Communication.

This contribution exploits the duality between a viral infection process and macroscopic air-based molecular communication. Airborne aerosol and droplet transmission through human respiratory processes is modeled as an instance of a multiuser molecular communication scenario employing respiratory-event-driven molecular variable-concentration shift keying. Modeling is aided by experiments that are motivated by a macroscopic air-based molecular communication testbed. In artificially induced coughs, a saturated aqueous solution containing a fluorescent dye mixed with saliva is released by an adult test person. The emitted particles are made visible by means of optical detection exploiting the fluorescent dye. The number of particles recorded is significantly higher in test series without mouth and nose protection than in those with a well-fitting medical mask. A simulation tool for macroscopic molecular communication processes is extended and used for estimating the transmission of infectious aerosols in different environments. Towards this goal, parameters obtained through self experiments are taken. The work is inspired by the recent outbreak of the coronavirus pandemic.

Evidence for the transfer of methadone and EDDP by sweat to children\u2019s hair

In cases where there is a question as to whether children have come into contact with drugs, examinations of their scalp hair are frequently carried out. Positive test results are often discussed in the forensic community due to the various possible modes via which drugs and their metabolites can be incorporated into the hair. These include drug uptake by the child (e.g. oral ingestion or inhalation), but also contamination of hair via contact with the sweat from drug users. In this study, the possibility of methadone and its metabolite EDDP being incorporated into children’s hair by contact with sweat from persons undergoing opiate maintenance therapy (methadone) was examined. The transfer of methadone and EDDP via sweat from methadone patients (n = 15) to children’s hair was simulated by close skin contact of drug-free children’s hair, encased in mesh-pouches, for 5 days. Sweat-collecting patches (hereafter referred to as ‘sweat patches’) were applied to the test persons’ skin. One strand of hair and one sweat patch were collected daily from each patient. Analyses were performed using GC–MS/MS (hair) and LC–MS/MS (serum, sweat patches). After 4 days of skin contact, methadone was detectable in the formerly drug-free hair strands in all 15 study participants. EDDP was detectable in 34 of 75 hair strands, with the maximum number of positive results (11 EDDP-positive hair strands) being detected after 5 days. These results show that transfer of methadone and EDDP to drug-free hair is possible through close skin contact with individuals taking part in methadone substitution programmes. A correlation between serum concentration, sweat concentration and substance concentration in hair strands could not be demonstrated, but a tendency towards higher concentrations due to longer contact time is clearly evident.

A randomized controlled trial evaluating combination detection of HIV in Malawian sexually transmitted infections clinics.

IntroductionHIV diagnosis is the necessary first step towards HIV care initiation, yet many persons living with HIV (PLWH) remain undiagnosed. Employing multiple HIV testing strategies in tandem could increase HIV detection and promote linkage to care. We aimed to assess an intervention to improve HIV detection within socio‐sexual networks of PLWH in two sexually transmitted infections (STI) clinics in Lilongwe, Malawi.MethodsWe conducted a randomized controlled trial to evaluate an intervention combining acute HIV infection (AHI) screening, contract partner notification and social contact referral versus the Malawian standard of care: serial rapid serological HIV tests and passive partner referral. Enrolment occurred between 2015 and 2019. HIV‐seropositive persons (two positive rapid tests) were randomized to the trial arms and HIV‐seronegative (one negative rapid test) and ‐serodiscordant (one positive test followed by a negative confirmatory test) persons were screened for AHI with HIV RNA testing. Those found to have AHI were offered enrolment into the intervention arm. Our primary outcome of interest was the number of new HIV diagnoses made per index participant within participants’ sexual and social networks. We also calculated total persons, sexual partners and PLWH (including those previously diagnosed) referred per index participant.ResultsA total of 1230 HIV‐seropositive persons were randomized to the control arm, and 561 to the intervention arm. Another 12,713 HIV‐seronegative or ‐serodiscordant persons underwent AHI screening, resulting in 136 AHI cases, of whom 94 enrolled into the intervention arm. The intervention increased the number of new HIV diagnoses made per index participant versus the control (ratio: 1.9; 95% confidence interval (CI): 1.2 to 3.1). The intervention also increased the numbers of persons (ratio: 2.5; 95% CI: 2.0 to 3.2), sexual partners (ratio: 1.7; 95% CI: 1.4 to 2.0) and PLWH (ratio: 2.3; 95% CI: 1.7 to 3.2) referred per index participant.ConclusionsCombining three distinct HIV testing and referral strategies increased the detection of previously undiagnosed HIV infections within the socio‐sexual networks of PLWH seeking STI care. Combination HIV detection strategies that leverage AHI screening and socio‐sexual contact networks offer a novel and efficacious approach to increasing HIV status awareness.

Effects of an Innovative Head-Up Tilt Protocol on Blood Pressure and Arterial Stiffness Changes.

The objective of our study was to identify blood pressure (BP) and pulse wave velocity (PWV) changes during orthostatic loading, using a new the head-up tilt test (HUTT), which incorporates the usage of a standardized hydrostatic column height. Methods: 40 healthy subjects 20–32 years performed HUTT, which was standardized to a height of the hydrostatic column at 133 cm. Exposure time was 10 min in each of 3 positions: horizontal supine 1, HUTT, and horizontal supine 2. The individual tilt up angle made it possible to set the standard value of the hydrostatic column. Hemodynamic parameters were recorded beat to beat using “Task Force Monitor 3040 i”, pulse-wave velocity (PWV) was measured with a sphygmograph–sphygmomanometer VaSera VS1500N. Results: Orthostatic loading caused a significant increase in heart rate (HR) and a decrease in stroke volume (SV) (p < 0.05) but no significant reductions in cardiac output, changes in total vascular resistance (TVR), or BP. An analysis of personalized data on systolic blood pressure (SBP) changes in tilt up position as compared to horizontal position (ΔSBP) revealed non-significant changes in this index in 48% of subjects (orthostatic normotension group), in 32% there was a significant decrease in it (orthostatic hypotension group) and in 20% there was a significant increase in it (orthostatic hypertension group). These orthostatic changes were not accompanied by any clinical symptoms and/or syncope. During HUTT, all subjects had in the PWV a significant increase of approximately 27% (p < 0.001). Conclusion: The new test protocol involving HUTT standardized to a height of hydrostatic column at 133 cm causes typical hemodynamics responses during orthostatic loading. Individual analysis of the subjects revealed subclinical orthostatic disorders (OSD) in up to 52% of the test persons. During HUTT, all test subjects showed a significant increase in PWV. The new innovative HUTT protocol can be applied in multi-center studies in healthy subjects to detect preclinical forms of orthostatic disorders under standard gravity load conditions.

Objective Accuracy Indicators of the Single-Joint Arm Movements Simultaneous Reproduction with Closed Eyes and under Visual Control in Patients with Hemiparesis and Healthy Test Subjects (a New Method for Proprioceptive Sensitivity Objective Assessment)

Aim. We have developed a method for objective assessment of proprioceptive sensitivity (PS) based on determining the accuracy of reproduction with the eyes closed of the tested arm passive single-joint movements by active movements of the other arm during their execution. It was shown that healthy test subjects reproduce the passive movements with high accuracy, while post-stroke patients with hemiparesis reproduce a large proportion of paretic arm test movements with gross qualitative and quantitative errors. To make sure that the reproduction errors are associated with the state of PS but not with the cognitive factor or the functional state of the conditionally healthy arm, it was necessary to find out how accurately these patients are able to reproduce the test-movements under visual control. Materials and Methods. In 11 patients with a lesion in the right and in 9 patients in the left hemispheres of the brain and a control group of 23 healthy subjects, the accuracy of reproduction of the 5 elementary hand movements was studied: flexion-extension in the shoulder, elbow and wrist joints and abduction–adduction in the shoulder and wrist joints. The test person was subjected to a series of passive cyclic movements of the test hand during which he had to copy them with active movements of the other hand. The reproduction procedure for each test movement was performed first under visual control and then with the eyes closed. The angles in the test join and the same joint of the other arm were recorded. Qualitative and quantitative indicators were used to assess the degree of similarity of active and passive movements and to reveal the correspondence of copying accuracy to the previously developed conditional criterion of the norm (CCN) of PS in healthy test subjects. Results. It was shown that in healthy test subjects the accuracy of all movements copying in tests with closed eyes and 98% of movements in tests with opened eyes met the requirements of the CCN. In the group of patients in tests with eyes closed, copying only 61% of movements met this criterion. 20.4% of movements were reproduced with qualitative gross errors, 18.4% were copied qualitatively correctly but differed from CCN in quantitative indicators. In tests with visual tracking of passive movements, reproduction of 98% of movements was qualitatively correct and 83% of movements corresponded to CCN. Conclusions. The vast majority of single-articular movements of the paretic arm are copied by patients with unilateral brain damage under visual control qualitatively correctly and accurately (meeting the CCN). It means that in the course of the study of PS by the proposed method, they, as a rule, understand the motor task and can reproduce the tested movements with their conditionally healthy arm. From this it follows that the main cause of these movements impaired copying in tests with closed eyes is proprioceptive deficit.

Ventilation and air cleaning to limit aerosol particle concentrations in a gym during the COVID-19 pandemic

SARS-CoV-2 can spread by close contact through large droplet spray and indirect contact via contaminated objects. There is mounting evidence that it can also be transmitted by inhalation of infected saliva aerosol particles. These particles are generated when breathing, talking, laughing, coughing or sneezing. It can be assumed that aerosol particle concentrations should be kept low in order to minimize the potential risk of airborne virus transmission. This paper presents measurements of aerosol particle concentrations in a gym, where saliva aerosol production is pronounced. 35 test persons performed physical exercise and aerosol particle concentrations, CO2 concentrations, air temperature and relative humidity were obtained in the room of 886 m³. A separate test was used to discriminate between human endogenous and exogenous aerosol particles. Aerosol particle removal by mechanical ventilation and mobile air cleaning units was measured. The gym test showed that ventilation with air-change rate ACH = 2.2 h−1, i.e. 4.5 times the minimum of the Dutch Building Code, was insufficient to stop the significant aerosol concentration rise over 30 min. Air cleaning alone with ACH = 1.39 h−1 had a similar effect as ventilation alone. Simplified mathematical models were engaged to provide further insight into ventilation, air cleaning and deposition. It was shown that combining the above-mentioned ventilation and air cleaning can reduce aerosol particle concentrations with 80 to 90% , depending on aerosol size. This combination of existing ventilation supplemented with air cleaning is energy efficient and can also be applied for other indoor environments.

Location- and Person-Independent Activity Recognition with WiFi, Deep Neural Networks, and Reinforcement Learning

In recent years, Channel State Information (CSI) measured by WiFi is widely used for human activity recognition. In this article, we propose a deep learning design for location- and person-independent activity recognition with WiFi. The proposed design consists of three Deep Neural Networks (DNNs): a 2D Convolutional Neural Network (CNN) as the recognition algorithm, a 1D CNN as the state machine, and a reinforcement learning agent for neural architecture search. The recognition algorithm learns location- and person-independent features from different perspectives of CSI data. The state machine learns temporal dependency information from history classification results. The reinforcement learning agent optimizes the neural architecture of the recognition algorithm using a Recurrent Neural Network (RNN) with Long Short-Term Memory (LSTM). The proposed design is evaluated in a lab environment with different WiFi device locations, antenna orientations, sitting/standing/walking locations/orientations, and multiple persons. The proposed design has 97% average accuracy when testing devices and persons are not seen during training. The proposed design is also evaluated by two public datasets with accuracy of 80% and 83%. The proposed design needs very little human efforts for ground truth labeling, feature engineering, signal processing, and tuning of learning parameters and hyperparameters.

DAILY-A Personalized Circadian Zeitgeber Therapy as an Adjunctive Treatment for Alcohol Use Disorder Patients: Study Protocol for a Randomized Controlled Trial.

Background: Hallmarks of alcohol use disorder (AUD) are disturbances of circadian rhythms and everyday structures. While circadian rhythms dictate the timing of daily recurring activities such as sleep, activity, and meals, conversely, these activities represent time cues, so called Zeitgebers, that the circadian system uses to synchronize with the environment. Here we present a study protocol for our newly developed therapy approach for AUD patients, in which we take advantage of this mutual influence and stabilize and strengthen their circadian system by creating strict daily schedules for daily Zeitgeber activities. Since every person has a circadian system with its own characteristics and is subject to social obligations, the daily plans are personalized for each test person. Our hypothesis is that a regular exposure to Zeitgebers stabilizes behavioral and physiological circadian rhythms and thereby reduces the risk of alcohol relapses and depressive symptoms and facilitates physical recovery in AUD patients during the 1st weeks of their addiction therapy.Methods/design: The study is a 6-weeks single site trial with a controlled, randomized, single-blinded, parallel-group design including patients with a diagnosis of AUD. The study runs parallel to the standard addiction therapy of the clinic. Patients are randomly assigned to either an intervention group (DAILY) or a sham control group (placebo treatment). Questionnaires and physiological assessments of both groups are conducted before and immediately after the intervention or control treatment. According to our hypothesis, the primary outcomes of this study are improvements of regularity, alcohol consumption, and relapse rate in AUD patients compared to AUD patients receiving control treatment. Secondary outcomes are reduced depressive symptoms and increased physical recovery.Discussion: This study is a randomized controlled trial to investigate the efficacy of a personalized circadian Zeitgeber therapy as an adjunctive treatment for alcohol use disorder patients. The overall goal of this and more extended future studies is the development of an adjunctive therapy for AUD patients that is uncomplicated in its use and easy to implement in the clinical and everyday routine.Trial registration: This study is registered at the German Clinical Trial Register with the trial number DRKS00019093 on November 28, 2019.

Psychophysical study of the moon illusion in paintings and landscape photos

The moon illusion is a visual deception when people perceive the angular diameter of the Moon/Sun near the horizon larger than that of the one higher in the sky. Some theories have been proposed to explain this illusion, but not any is generally accepted. Although several psychophysical experiments have been performed to study different aspects of the moon illusion, their results have sometimes contradicted each other. Artists frequently display(ed) the Moon/Sun in their paintings. If the Moon/Sun appears near the horizon, its painted disc is often exaggeratedly large. How great is the magnitude of moon illusion of painters? How different are the size enlargements of depicted lunar/solar discs? To answer these questions, we measured these magnitudes on 100 paintings collected from the period of 1534–2017. In psychophysical experiments, we also investigated the moon illusion of 10 test persons who had to estimate the size of the lunar/solar disc on 100 paintings and 100 landscape photographs from which the Moon/Sun was retouched. Compared to the lunar/solar disc calculated from reference distances estimated by test persons in paintings, painters overestimated the Moon's size on average Q = 2.1 ± 1.6 times, while the Sun was painted Q = 1.8 ± 1.2 times larger than the real one, where Q = r painted / r real is the ratio of the radii of painted ( r painted ) and real ( r real ) Moons/Suns. In landscape photos, test persons overestimated the Moon's size Q = 1.6 ± 0.4 times and the Sun was assumed Q = 1.7 ± 0.5 times larger than in reality, where Q = r test / r real is the ratio of the radius r test estimated by the test persons and the real radius r real of Moons/Suns. The majority of the magnitude of moon illusion Q = 1.6, 1.7, 1.8, 2.1, 2.8, 2.9 measured by us are larger than the Q -values 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.8 obtained in previous psychophysical experiments due to methodological differences.

A validation study on the thermal simulation of the human body-clothing-environment system through wear trials

The following analysis deals with the validation study for the already published thermal simulation of the human body-clothing-environment system through wear trials. Three test persons and a clothing system were selected for this study. The simulation process chain includes 3D scanning, clothing fit considering the deformation properties of fabrics, 3D analysis of air gaps between skin and clothing, and thermophysiological analysis of the human body taking into account different metabolic rates. Moreover, subjective wear trials were performed in a climatic chamber to validate the simulation results. The results show good validation for the core body and mean skin temperature, however, discrepancies were observed on comparing the local skin temperatures. The presented simulation approach offers a holistic solution for product development in the areas of sportswear, workwear, outdoor, and protective clothing.

Motion Capturing in Connection With Human Model Simulation and Artificial Intelligence AI for Employee Training in the Area of Joint-gentle Assembly Workflows in Production Environment

Teaching at assembly workstations in production in SMEs (small and medium sized companies) often does not take place at all or only insufficiently. In addition to the lack of technical content, there are also aggravatingly incorrect movement sequences from an ergonomic point of view, which untrained people usually automatically acquire. An AI based approach is used to analyze a definite workflow for a specific assembly scope regarding the behavior of several employees. Based on these different behaviors, the AI gives feedback at which points in time, work steps and movement’s particularly dangerous incorrect postures occur. Motion capturing and digital human model simulation in combination with the results of the AI define the optimized workflow. Individual employees can be trained directly due to the fact that AI identifies their most serious incorrect postures and provide them with a direct analogy of their “wrong” posture and “easy on the joints posture”. With the assistance of various test persons, the AI can conduct a study in which the most frequently occurring incorrect postures can be identified. This could be realized in general or tailored to specific groups of people (e.g. People over 1.90m tall must be particularly careful not to make the following mistake...). The approach will be tested and validated at the Werk150, the factory of the ESB Business School, on the campus of the Reutlingen University. The new gained knowledge will be used subsequently for training in SMEs.

Psychophysical Study of Human Visual Perception of Flicker Artifacts in Automotive Digital Mirror Replacement Systems

Aliasing effects due to time-discrete capturing of amplitude-modulated light with a digital image sensor are perceived as flicker by humans. Especially when observing these artifacts in digital mirror replacement systems, they are annoying and can pose a risk. Therefore, ISO 16505 requires flicker-free reproduction for 90% of people in these systems. Various psychophysical studies investigate the influence of large-area flickering of displays, environmental light, or flickering in television applications on perception and concentration. However, no detailed knowledge of subjective annoyance/irritation due to flicker from camera-monitor systems as a mirror replacement in vehicles exist so far, but the number of these systems is constantly increasing. This psychophysical study used a novel data set from real-world driving scenes and synthetic simulation with synthetic flicker. More than 25 test persons were asked to quantify the subjective annoyance level of different flicker frequencies, amplitudes, mean values, sizes, and positions. The results show that for digital mirror replacement systems, human subjective annoyance due to flicker is greatest in the 15 Hz range with increasing amplitude and magnitude. Additionally, the sensitivity to flicker artifacts increases with the duration of observation.

On the suitability of the distance between the tip of the nose and the middle of the elbow joint for sneezing etiquette as corona infection prophylaxis

During the current corona pandemic, the question to which extent people could reach the middle of the elbow joint with the tip of their nose, which the Federal Ministry of Health recommended as a preventive measure when sneezing, was investigated with the help of an online questionnaire.&#x0D; The analysis included 316 fully completed online questionnaires and 16 additional telephone interviews, a total of 332 test persons (average age 29.5 (± 14.3) years, average BMI 22.9 (± 3.4) kg/m²; 226 women, 106 men).&#x0D; The results of this study show that 84.6% of respondents followed the recommended coughing etiquette and sneezed into the crook of their arm, 15.4% did not. The most common reason given for not using it was habit. Nevertheless, 92.8% of the participants found sneezing or coughing in the crook of their arm to be useful.&#x0D; When measuring the distance, 76.2% of the participants were able to touch the crook of the arm at the specific angle on both sides. The average measured distance was 1.13 cm on the right and 1.23 cm on the left. It was found that the BMI and age had a significant relationship with the measured distance. In a gender-specific comparison, more women than men sneezed into the crook of their arm, while no significant differences were found when measuring the distance.&#x0D; If the results of this study are put into practice, it makes perfect sense to continue to recommend sneezing or coughing in the crook of the arm. However, a note should be attached to this recommendation, which prompts one to take the sneeze position once and to check whether the crook of the arm can really be reached effectively. If this is not possible, alternative options should be recommended.

A Simulation Study on Effects of Platooning Gaps on Drivers of Conventional Vehicles in Highway Merging Situations

Platooning refers to a group of vehicles that—enabled by wireless vehicle-to-vehicle (V2V) communication and vehicle automation—drives with short inter-vehicular distances. Before its deployment on public roads, several challenging traffic situations need to be handled. Among the challenges are cut-in situations, where a conventional vehicle—a vehicle that has no automation or V2V communication—changes lane and ends up between vehicles in a platoon. This paper presents results from a simulation study of a scenario, where a conventional vehicle, approaching from an on-ramp, merges into a platoon of five cars on a highway. We created the scenario with four platooning gaps: 15, 22.5, 30, and 42.5 meters. During the study, the conventional vehicle was driven by 37 test persons, who experienced all the platooning gaps using a driving simulator. The participants’ opinions towards safety, comfort, and ease of driving between the platoon in each gap setting were also collected through a questionnaire. The results suggest that a 15-meter gap prevents most participants from cutting in, while causing potentially dangerous maneuvers and collisions when cut-in occurs. A platooning gap of at least 30 meters yield positive opinions from the participants, and facilitating more smooth cut-in maneuvers while less collisions were observed.