Test Persons Research Articles

In vivo assessment of artefacts in MRI images caused by conventional twistflex and various fixed orthodontic CAD/CAM retainers.

To assess magnetic resonance imaging (MRI) artefacts caused by different computer-aided design/computer-aided manufacturing (CAD/CAM) retainers in comparison with conventional hand bent stainless steel twistflex retainers in vivo. MRI scans (3 Tesla) were performed on amale volunteer with different CAD/CAM retainers (cobalt-chromium, CoCr; nickel-titanium, NiTi; grade5 titanium, Ti5) and twistflex retainers inserted. Atotal of 126 landmarks inside and outside the retainer area (RA; from canine to canine) were evaluated by two blinded radiologists using an established five-point visibility scoring (1: excellent, 2: good, 3: moderate, 4: poor, 5: not visible). Friedman and two-tailed Wilcoxon tests were used for statistical analysis (significance level: p < 0.05). Twistflex retainers had the strongest impact on the visibility of all landmarks inside (4.0 ± 1.5) and outside the RA (1.7 ± 1.2). In contrast, artefacts caused by CAD/CAM retainers were limited to the dental area inside the RA (CoCr: 2.2 ± 1.2) or did not impair MRI-based diagnostics in aclinically relevant way (NiTi: 1.0 ± 0.1; Ti5: 1.4 ± 0.6). The present study on asingle test person demonstrates that conventional stainless steel twistflex retainers can severely impair the diagnostic value in head/neck and dental MRI. By contrast, CoCr CAD/CAM retainers can cause artefacts which only slightly impair dental MRI but not head/neck MRI, whereas NiTi and Ti5 CAD/CAM might be fully compatible with both head/neck and dental MRI.

Magnetic resonance imaging with a stress drinking test as a method of assessing the evacuation function of the stomach

Aim: to study opportunity of research the evacuation function of the stomach in young people by magnetic resonance imaging with a stress drinking test. Materials and methods: the study group included 20 young people (10 men and 10 women aged 23 ± 1,12 years). At the time of the study, each test person excluded organic and functional pathologies of the gastroduodenal zone. A method of magnetic resonance imaging of the stomach with a stress drinking test (still drinking water at room temperature with a volume of 1000.0 ml) was used. The examination lasted 30 minutes, scanning was carried out every 5 minutes, a total of 7 scans. Based on the obtained three-dimensional images of the DICOM format using the HorosMobile™ application (DICOM medical image viewer), the volumes of fluid in the stomach in dynamics were calculated for each test person in the study group according to the time intervals of the scans performed by the magnetic resonance imaging machine. Systematization and data processing were carried out a Microsoft Excel. A single graph was built for the study group in the Pages graphical editor (iWork productivity suite) based on the obtained data, reflecting the reference volumes of gastric contents relative to the time scale with possible deviations from the average. Results: regardless of the type of physique and shape of the stomach in the studied subjects, the evacuation of a larger volume of fluid (81,53-82,54%) occurred by the 15th minute of the study. Complete evacuation of gastric contents occurs between 25 and 30 minutes of the study. Conclusions: the results obtained by MRI studies of the stomach with a stress drinking test give an idea of the options for normal physiological evacuation of gastric contents in young people, in the absence of organic and functional pathology of the gastroduodenal zone.

Music for the Heart—Can Heart Rate Be Influenced by Different Music Genres or Modulated Sounds? A Comparison between Healthy Young and Elderly People and Patients with Parkinson’s Disease

Introduction: The aim of the present study was to analyze the influence of different music genres, three modulated noises and a pink noise on the heart rate (HR) and to compare between young healthy adults (YA), elderly healthy adults was (EA) and patients with Parkinson’s disease (PD). Furthermore, a sound condition comparison for each group was conducted. Methods: A total of 77 subjects (41m/36w) were divided into healthy adults aged 20–35 years (YA) and 55–76 years (EA) as well as adults diagnosed with Parkinson’s disease (42–76 years) (PD). The “Polar OH1”, an optical pulse sensor, determined the heart rate. All test persons used identical wireless headphones (Bose QC35). The music genres were classical, relaxation and heavy metal with different speeds (bpm) while the three modulated noises were equivalent to these three music styles. To exclude visual information, everyone wore a blindfold. Significance was set at 5%. Results: When comparing experimental conditions within a subject group, there was a significant difference (p ≤ 0.001). between the different measurement mostly in group YA but barely noticeable in group EA. Subject group PD had no significant condition differences. For each sound condition the median HR was higher in YA than in EA (p ≤ 0.001–0.05). Conclusion: The heart rate was not affected by wearing headphones with or without the noise canceling mode. While listening to the music or the tones, younger people have a higher HR variability than older people which may, thus, make them more sensitive to the conditions studied. It can be assumed that the listening to music has no systematic influence on decreasing or increasing the HR.

Expression of parlour behaviour, temperament, welfare and approach test in postpartum Surti buffaloes (Bubalus bubalis)

The present study was carried out at Livestock Research Station, Navsari Agricultural University, Navsari, Gujarat to investigate the effect of parity on milking parlour behaviour, temperament and welfare of postpartum Surti buffaloes. Fourteen postpartum Surti buffaloes were selected and grouped based on parity as primiparous and multiparous (2nd to 5th lactation). The milking behaviour of experimental animals was observed on the day of calving, 7th, 15th, 30th, 45th, 60th and 80th day post-calving keeping in view the peak production of buffaloes. The primiparous animals showed higher milk let down time and milking time, and lower rate of milk flow as compared to multiparous animals. The frequency of incidences of urination, defecation, kicking and stepping were significantly higher in primiparous group. The primiparous animals exhibited more avoidance behaviour when approached by a test person, indicative of more agitation. During milking and in paddock, primiparous animals were more aggressive and restless as compared to multiparous animals which exhibited calmer and docile temperament. From the present study, it could be conferred that parity significantly influences the parlour behaviour, temperament and welfare in postpartum Surti buffaloes.

Effect of repeated bolus and continuous glucose infusion on a panel of circulating biomarkers in healthy volunteers.

Glycaemic variability (GV) refers to fluctuations in the blood glucose level and may contribute to complications in patients suffering from Diabetes. Several studies show negative effects of GV on the cardiovascular system, however there is still a lack of conclusive evidence. Using an explorative cardiovascular panel, it is possible to simultaneously measure the effects on proteins relevant for cardiovascular processes. The aim of this study was to investigate the effects of rapid glucose excursions on cardiovascular and metabolic parameters in healthy individuals. An explorative single-blinded cross-over study was performed in ten healthy men. Subjects received 3 times 20 grams of glucose i.v. over 5 minutes or 60 grams of glucose continuously over 3 hours. Blood was taken for repeated measurements of the cardiovascular panel over the following 6 hours and again after 24 and 48 hours. We observed a significant elevation of 7 cardiovascular biomarkers (BMP6, SLAMF7, LOX-1, ADAMTS13, IL-1RA, IL-4RA, PTX3) at t = 360min after rapid glucose infusion compared to a continuous glucose infusion. Intraday GV seems to have acute effects on cardiovascular proteins in healthy test persons. Rapid glucose administration compared to continuous administration showed significant changes in BMP6, SLAMF7, ADAMTS13, IL1RA, PTX3, IL-4RA and LOX-1. NCT04488848.

Design and development of an e-learning patient education program for self-management support in patients with rheumatoid arthritis

To develop an e-learning education program targeting patients with rheumatoid arthritis. The development process involved content specification and creative design. It was theoretically framed within theories of multimedia learning and entertainment-education and empirically based on evidence of patient education in rheumatoid arthritis and focus group discussions with stakeholders. We conducted a feasibility test among ten patients to assess the acceptability and usability of the program, and to identify areas to be adjusted. The following themes for educational needs were found in focus group discussions: “Knowledge of rheumatoid arthritis,” he disease course and prognosis,” “Medical treatment,” “A new life situation” and “Daily life with rheumatoid arthritis.” Based on this, an e-learning program covering the disease course, examinations, treatment, and daily life, was created. It combines animations, videos, podcasts, text, speech, and tests. Test persons found the program feasible—that is, clear in content and easy to understand with a suitable pace and coherence between graphics, speech, and text. This e-learning program is based on solid theoretical knowledge that meets users' needs and is easy to use. This study contributes to the innovation of health care by the development of a new digital tool for patient education.

The colonoscopic vacuum model–simulating biomechanical restrictions to provide a realistic colonoscopy training environment

IntroductionPracticing endoscopic procedures is fundamental for the education of clinicians and the benefit of patients. Despite a diverse variety of model types, there is no system simulating anatomical restrictions and variations in a flexible and atraumatic way. Our goal was to develop and validate a new modelling approach for adhesion forces between colon and abdominal wall.MethodsAn inlay for a standard mechanical trainer was designed and 3D printed. Colon specimens were fixed to the inlay along colon ascendens (CA) and colon descendens (CD) by a vacuum. Our system, which we refer to as Colonoscopy Vacuum Model (CoVaMo), was validated with 11 test persons with varying level of expertise. Each performed one colonoscopy and one polypectomy in the CoVaMo and in the Endoscopic Laparoscopic Interdisciplinary Training Entity (ELITE). Achieved adhesion forces, times required to fulfill different tasks endoscopically and a questionnaire, assessing proximity to reality, were recorded.ResultsMean adhesion forces of 37 ± 7 N at the CA and 30 ± 15 N at the CD were achieved. Test subjects considered CoVaMo more realistic than ELITE concerning endoscope handling and the overall anatomy. Participants needed statistically significantly more time to maneuver from anus to flexura sinistra in CoVaMo (377 s ± 244 s) than in ELITE (58 s ± 49 s).ConclusionWe developed a training environment enabling anatomically and procedural realistic colonoscopy training requiring participants to handle all endoscope features in parallel. Fixation forces compare to forces needed to tear pig colon off the mesentery. Workflow and inlay can be adapted to any arbitrary ex vivo simulator.

Addressing methodological assumptions of correspondence tests when measuring discrimination

ABSTRACT In this study, we introduce a critical assessment of methodological assumptions made by researchers when using correspondence tests to measure ethnic discrimination. We aim to investigate whether (1) the order in which the applications are sent out, between the test and control person, (2) the conducted matched triad tests, in comparison to matched duo tests, and (3) the timing of application within the week, have an effect on discrimination rates. For this purpose, we made use of 2.984 matched correspondence tests across Flanders, the Dutch-speaking part of Belgium. Our findings suggest that the correspondence tests are rather robust for the variability in methodology. While these different methodological choices do affect the general invitation rates, they do not affect discrimination rates.

Consistency of vertebral motion and individual characteristics in gait sequences

Vertebral motion reveals complex patterns, which are not yet understood in detail. This applies to vertebral kinematics in general but also to specific motion tasks like gait. For gait analysis, most of existing publications focus on averaging characteristics of recorded motion signals. Instead, this paper aims at analyzing intra- and inter-individual variation specifically and elaborating motion parameters, which are consistent during gait cycles of particular persons. For this purpose, a study design was utilized, which collected motion data from 11 asymptomatic test persons walking at different speed levels (2, 3, and 4 km/h). Acquisition of data was performed using surface topography. The motion signals were preprocessed in order to separate average vertebral orientations (neutral profiles) from basic gait cycles. Subsequently, a k-means clustering technique was applied to figure out, whether a discrimination of test persons was possible based on the preprocessed motion signals. The paper shows that each test sequence could be assigned to the particular test person without additional prior information. In particular, the neutral profiles appeared to be highly consistent intra-individually (across the gait cycles as well as speed levels), but substantially different between test persons. A full discrimination of test persons was achieved using the neutral profiles with respect to flexion/extension data. Based on this, these signals can be considered as individual characteristics for the particular test persons.

The GENESIS-UV study on ultraviolet radiation exposure levels in 250 occupations to foster epidemiological and legislative efforts to combat nonmelanoma skin cancer.

Several hundred million of the 3 billion formally employed people worldwide are at risk from high levels of solar ultraviolet radiation (UVR). Chronic light damage to the skin can lead to nonmelanoma skin cancer (NMSC), especially when irradiation is too high and is acquired for decades. However, data with uniform metrics, high resolution over time and in-depth occupational profiles are not available. To build a worldwide usable matrix of UVR exposure in occupations and to show use cases for the data. One thousand test persons were recruited to wear electronic data logger dosimeters during their working time for 7 months each. The measurements yielded 3.7 billion data points for around 48 000 days with high-quality data capture covering more than 250 occupations and 650 activities. Scientific evaluation of the data included daily and half-hourly means, geographical transfer calculations to the world, threshold exceedance quotas, transcriptome effects, and occupational disease estimates. A compendium for global use is presented. In-depth analyses and the resulting implications for research have been elaborated to directly link exposure data to effects in the human body. Interestingly, the annual irradiances of the different occupations span a wide range of values: from about 650 to 50 standard erythemal doses, with different distributions over the months. Detailed exposure data per occupation were derived, and the risk on an occupational or activity basis assuming different exposure level quotas was quantified. This showed that, for example, in temperate latitudes, all activities with a duration of > 2 h outdoors are associated with increased NMSC risk. We offer our work to enable sound studies on the nature of ultraviolet-induced skin cancer, dose-response relationships, intermittency of skin exposure, and derivation of limit values. Sociological studies on prevention are now possible. Practitioners may use the findings for their daily work with employees.

Initial results of the evaluation of a digital rollator

Rollators are preferred to compensate physiological limitations and to maintain mobility in old age; however, environmental obstacles or limited perception of fall hazards can lead to fall events. The present study evaluates an electronic box that is used to supplement conventional rollators with various technical assistance systems (e.g. call for help to contact persons, fall detection). The rollator equiped with the electronic box (DigiRoll) was tested for its suitability for everyday use during the pilot phase of the study, with the aim of further development. In aqualitative design, the DigiRoll was tested in apilot phase with 10participants. Individuals were interviewed in focus groups and individual interviews. In addition, ethnographic observations were made. The data evaluation was carried out using qualitative content analysis. The test persons showed great interest in the development of the assistance systems to increase the feeling of safety. At the same time, the necessity of adapting the DigiRoll to individual needs became clear, depending on the living situation, the type of impairment and personal habits. The DigiRoll has the potential to provide sustainable support for people with reduced mobility by increasing the users' sense of safety. Other contextual factors such as access to suitable rollators and safe walkways cannot be influenced by the DigiRoll.

Composite performance of variable stiffness actuator for exoskeleton administrated via impedance control and disturbance observer

This paper presents an integration of two significant targets, i.e., reducing the output impedance and the vibration at the trajectory tracking, into one variable stiffness actuator (VSA) system. The VSA is operated within the cascade impedance control framework, in which the inner torque control loop is designed with the unknown input observer (UIO). The gain-scheduled UIO cooperates with the low and high physical stiffness of the VSA to achieve the low-output impedance and steady trajectory tracking, respectively. The rationality of these implementations is presented considering the stiffness constant and the performance of the control system. The VSA and the gain scheduling-based variable impedance control follow the paradigm of the continuous variable impedance task. In accordance with the knee joint torque, the low and high impedance task with the enhanced performance are applied to a knee exoskeleton with the VSA joint. The effectiveness of the controllers is experimentally verified on a VSA prototype and the exoskeleton with the test person. The robust stability and passivity of the whole control system with the bounded parameter variation rate are investigated.

Fullfield and extrafoveal visual evoked potentials in healthy eyes: reference data for a curved OLED display

PurposeVisual evoked potentials (VEP) present an important diagnostic tool in various ophthalmologic and neurologic diseases. Quantitative response data varied among patients but are also dependent on the recording and stimulating equipment. We established VEP reference values for our setting which was recently modified by using a curved OLED display as visual stimulator. Distinction is made between fullfield (FF) and extrafoveal (EF) conduction, and the effect of sex, age and lens status was determined.MethodsThis prospective cross-sectional study included 162 healthy eyes of 162 test persons older than 10 years. A fullfield pattern-reversal visual evoked potential (FF-PR-VEP) with two stimulus sizes (ss) (20.4′ and 1.4°) as well as an extrafoveal pattern onset–offset VEP (EF-P-ON/OFF-VEP) (ss 1.4° and 2.8°) was derived in accordance with the International Society for Clinical Electrophysiology of Vision guidelines. Amplitudes and latencies were recorded, and the mean values as well as standard deviations were calculated. Age- and sex-dependent influences and the difference between phakic and pseudophakic eyes were examined. A subanalysis of EF-P-ON/OFF-VEP and fullfield pattern onset–offset VEP (FF-P-ON/OFF-VEP) was performed. A 55-inch curved OLED display (LG55EC930V, LG Electronics Inc., Seoul, South Korea) was used as visual stimulator.ResultsMean P100 latency of the FF-PR-VEP was 103.81 ± 7.77 ms (ss 20.4′) and 102.58 ± 7.26 ms (ss 1.4°), and mean C2 latency of the EF-P-ON/OFF-VEP was 102.95 ± 11.84 ms (ss 1.4°) and 113.58 ± 9.87 ms (ss 2.8°). For all stimulation settings (FF-PR-VEP, EF-P-ON/OFF-VEP), a significant effect of age with longer latencies and smaller amplitudes in older subjects and higher amplitudes in women was observed. We saw no significant difference in latency or amplitude between phakic and pseudophakic eyes and between EF-P-ON/OFF-VEP and FF-P-ON/OFF-VEP.ConclusionsA curved OLED visual stimulator is well suited to obtain VEP response curves with a reasonable interindividual variability. We found significant effects of age and gender in our responses but no effect of the lens status. EF-P-ON/OFF-VEP tends to show smaller amplitudes.

Preliminary Biomechanical Evaluation of a Novel Exoskeleton Robotic System to Assist Stair Climbing

A novel exoskeleton robotic system was developed to assist stair climbing. This active demonstrator consists of a motor with a cable system, various sensors, and a control system with a power supply. The objective of this preliminary study is a biomechanical evaluation of the novel system to determine its effectiveness in use. For this purpose, three test persons were biomechanically investigated, who performed stair ascents and descents with and without the exoskeleton. Kinematics, kinetics, and muscle activity of the knee extensors were measured. The measured data were biomechanically simulated in order to evaluate the characteristics of joint angles, moments, and reaction forces. The results show that the new exoskeleton assists both the ascent and the descent according to the measured surface electromyography (sEMG) signals, as the knee extensors are relieved by an average of 19.3%. In addition, differences in the interaction between the test persons and the system were found. This could be due to a slightly different operation of the assisting force or to the different influence of the system on the kinematics of the users.

Detectability of oxandrolone, metandienone, clostebol and dehydrochloromethyltestosterone in urine after transdermal application.

Situations of both, intentional and inadvertent or accidental doping, necessitate consideration in today's doping controls, especially in the light of the substantial consequences that athletes are facing in case of so-called adverse analytical findings. The aim of this study was to investigate, whether a transdermal uptake of doping substances would be possible. In addition to the period of detectability of the particular substances or respective characteristic metabolites, the possibility of deducing the route of administration by metabolite patterns was also assessed. Twelve male subjects were included in the study. Four common anabolic androgenic steroids (AAS) were dissolved in dimethylsulfoxide to facilitate transdermal administration on different skin regions. One half of the test persons received only oxandrolone (17α-methyl-2-oxa-4,5α-dihydrotestosterone), and the other half were applied a mixture of oxandrolone, metandienone (17β-hydroxy-17α-methylandrosta-1,4-dien-3-one), clostebol (4-chlorotestosterone-17β-acetate) and dehydrochloromethyltestosterone (DHCMT). Urine samples were collected 1 h, 6 h and one sample per day for the next 14 consecutive days. Measurements were conducted on a tandem-gas chromatography-mass spectrometry (GC-MS/MS) or tandem-liquid chromatography-MS/MS (LC-MS/MS) system. Substance findings were obtained at least 1 day after application on nearly all skin locations. The results indicated inter-individual variability in detection windows, also varying between the different analytes and possible impact of skin location and skin thickness, respectively. Nevertheless, a rapid and rather long detectability of all substances (or respective metabolites) was given, in some cases within hours after administration and for up to 10-14 days. Hence, the transdermal application or exposure to the investigated AAS is a plausible scenario that warrants consideration in anti-doping.

A participatory approach to redesign a tube connecting system for home parental nutrition

Abstract Patients receiving parenteral nutrition at home suffer from a lower quality of life as they receive continuous therapy for up to 16 hours a day. It is not possible to interrupt nutriton therapy for everyday activities, as any interruption poses a health risk to the patient. Therefore, a ambulatory care services comes twice a day to connect and disconnect. The aim of this project is to develop a system that makes it manageable for patients to interrupt their feeding therapy in a self-determined way. In order to achieve this, enginners and social scientists collaborated to conduct an ergonomics study using the Design of Experiments(DoE) method to compare three commonly used connection systems. Analysis of variance(ANOVA) was used to secure the tests. In parallel, the probands were asked about their subiective feelings during the closure process. The results provided indications for the redesign of a home parenteral nutrition system. As safety is a crucial issue, the opening and closing process of the system was virtually simulated with the min. and max. finger force of the test persons in order to ensure a safe connection and disconnection with the system at all times. Overall, this participatory approach enable the design of the closure system to take account patients'fears wishes.

Associations Between Physical Activity, Fundamental Motor Skills, And Physical Fitness In Norwegian Preschooler`s

PURPOSE: The importance of moderate-to-vigorous physical activity (MVPA) for physical fitness (FIT) and motor development is well established in school-aged children and adolescents. As many children have suboptimal motor skills and FIT, early childhood has been highlighted as an important phase for optimizing MVPA levels, and such, possibly improve FIT and motor skills. However, the relationship between MVPA and FIT and motor skills have had limited testing in preschool populations. The aim of this study was to investigate cross-sectional associations between MVPA and a broad set of motor skill and FIT measures in a large sample of preschoolers. METHODS: A sample of 1047 children (mean age 4.3 yr, 52% boys) from the Active Learning Norwegian Preschool(er)s Study participated during 2020-2021. MVPA was measured by accelerometry (Actigraph GT3x+) for 7 days and data were analysed using 1-sec epoch. MVPA was defined as ≥2296 counts. FMS were evaluated by a process-oriented test battery (9 items) across the domains: total score, locomotor, object control, and balance skills. FIT was assessed through three tests including speed-agility, hand grip, and standing long jump. A linear mixed model adjusted for sex, age, BMI (kg/m2), accelerometer wear time, and test person, was applied. RESULTS: There were significant, positive associations between MVPA and total skill score (β (95 % CI): 18 (13.8, 22.2), p < 0.001), locomotor- (14 (10.6, 17.3), p < 0.001), object control- (11.8 (8.5, 15.1), p < 0.001), and balance skills (5.4 (2.5, 8.3), p < 0.001), long jump (0.2 (0.2, 0.3), p < 0.001), and hand grip (1,2 (0.7, 1.7), p < 0.001), and a negative association with speed-agility (-1.6 (-2, -1.2), p < 0.001). CONCLUSIONS: Our findings demonstrate that MVPA is favorably and strongly associated with many dimensions of motor skills and FIT in preschoolers. As physical activity is a modifiable behavior, our findings suggests that promotion of MVPA might improve children’s motor skills and FIT levels during early childhood.

The Protective Performance of Process Operators' Protective Clothing and Exposure Limits under Low Thermal Radiation Conditions.

Simple SummaryProcess operators have an important monitoring role in the petrochemical industry. In the event of process disruptions and incidents, a process operator is often the first responder and takes measures to diminish the effects of an incident. Thus, a process operator can be exposed to dangerous circumstances, and therefore personal protective equipment has to be worn. In case of fire, the operator may be exposed to high heat radiation levels. Previous studies have established maximum acceptable heat radiation levels for long- (>15 min) and short-term exposures (<5 min), these being 1.0 kW/m2 and 1.5 kW/m2, respectively. These limits were based on manikin measurements and physiological models. The validation of the protection of operators’ clothing in human trials is lacking. Therefore, twelve professional firefighters were exposed to three different heat radiation levels in process operators’ clothing. The experiments showed that the majority of the operators can be exposed for 5 min to 1.5 kW/m2, up to 3 min to 2.0 kW/m2, while exposure to 2.5 kW/m2 or above must be avoided. Due to a slower skin temperature rise, loose-fitting protective clothing was related to longer exposure times. We speculate that additional long-armed/legged (under)clothing may offer more protection and extend the exposure time to heat radiation.During the early stage of a fire, a process operator often acts as the first responder and may be exposed to high heat radiation levels. The present limit values of long- (>15 min) and short-term exposure (<5 min), 1.0 and 1.5 kW/m2, respectively, have been set using physiological models and manikin measurements. Since human validation is essentially lacking, this study investigated whether operators’ protective clothing offers sufficient protection during a short-term deployment. Twelve professional firefighters were exposed to three radiation levels (1.5, 2.0, and 2.5 kW/m2) when wearing certified protective clothing in front of a heat radiation panel in a climatic chamber (20 °C; 50% RH). The participants wore only briefs (male) or panties and a bra (female) and a T-shirt under the operators’ clothing. Skin temperatures were continuously measured at the chest, belly, forearm, thigh, and knee. The test persons had to stop if any skin temperature reached 43 °C, at their own request, or when 5 min of exposure was reached. The experiments showed that people in operators’ clothing can be safely exposed for 5 min to 1.5 kW/m2, up to 3 min to 2.0 kW/m2, and exposure to 2.5 kW/m2 or above must be avoided unless the clothing can maintain an air gap.

Online Model Predictive Motion Cueing With Real-Time Driver Prediction

In this article a motion cueing algorithm (MCA) based on model predictive control (MPC) for a hexapod-based dynamic driving simulator is derived. The design objective of the MCA is to reproduce the real world accelerations and angular velocities for a test person in the simulator while respecting its actuator limitations. This results in an underlying nonlinear, state-constrained optimal control problem. In order to exploit the full predictive potential of the described algorithm, a method to predict the future driver behavior and thus the future desired values for the MPC is derived by modeling the driver as an optimal controller. The OCP weights that mainly influence the predicted driving actions are learned from demonstration using an inverse optimal control (IOC) approach. Furthermore, the direct incorporation of human perception models into the motion planning process is considered. An online driver-in-the-loop experiment with the Daimler driving simulator shows the high potential of the derived MPC scheme compared to the commonly used filter-based approach as well as the efficiency of the underlying optimization method.

The Impact of Optical Impressions on Dog Feeding Practice

According to the literature, as many as 60% of domestic dogs are overweight, whereby obesity is implicated in many serious diseases and hence a reduction of body weight results in a reduced risk of disease. Approximately 32% of reduction diets are unsuccessful in helping dogs to reach their ideal body weight. The likely reasons for this high drop-out rate include, among others, the fear of increased hunger-induced distress or a loss of affection on the part of the pet towards the owner. To alleviate these apprehensions, the use of optical effects that increase the perceived food intake could be useful. To investigate this, a mixed-methods study design was applied and 100 test persons—including dog owners and non-owners—were instructed to fill up 11 separate dog bowls with the same amount of dogfood. The bowls varied in 5 different variables (total height, upper diameter, angulation of sidewall, volume, and color). The influence of the shape and color of the dog bowls in relation to the filling quantity was evaluated. Overall, the body of the inner food bowl—especially its diameter and shape—showed a significant impact on the feeder as the wider the diameter, the more the dog bowl was filled. Moreover, the flatter the sidewall was angulated, the larger the fill-up quantity. Significantly, the volume on its own did not have a significant impact on the feeder. A difference of up to 37.6% in fill quantity resulted depending on the type of dog bowl used. Furthermore, the use of inner cones confused the test persons whereas different colors and the total height of the bowl showed no impact. Dog bowls with a small upper diameter and a steep sidewall—regardless of volume and color—were filled less by the test persons. This tendency could be useful for adapting the feeding of overweight dogs or those with an increased risk of obesity.