Human factors and ergonomics

Using a wheelchair can be a challenging task for people with reduced force and control of muscles of abdomen or lower back. Spinal cord injured (SCI) people are the majority of those who are spending most of the day on a wheelchair and a proper training and chair setup is mandatory to reach a good level of functionality and to avoid harms and side effects. In order to assess the complex motion of a person self-pushing a wheelchair, a motion capture (Mocap) system has been arranged and a group of SCI patients has been acquired in a hospital gym. The Mocap system uses three Microsoft Kinect RGB-D sensors and iPisoft to perform the recording of the 3D motion. The main goal of the research is to provide therapists with a quantitative method to define a preliminary configuration in an objective way once is given the user's medical conditions and his/her way of using the wheelchair. Working side by side with physiotherapists, the main parameters to be evaluated (e.g. pushing angles) have been identified and algorithms have been identified to automatically extract them from the 3D digital avatar model data coming from the Mocap system. The performance of the patients is then analyzed taking into account the wheelchair setup (e.g. position and inclination of the seat and of the back). The influence of geometric parameters on patients' motion is analyzed so that design guidelines for configuration can be found. The overall outcome is to maximize performance and minimize side effects and fatigue, providing users with a better experience on the wheelchair.

The Natural User Interface (NUI), which permits a simple and consistent user's interaction, represents a meaningful challenge for developing virtual/augmented reality applications. This paper presents a set of guidelines to design optimal NUI as well as a software framework, named FrameworkVR, which encapsulates the rules of presented guidelines. FrameworkVR allows developing NUI for VR/AR reality applications based on Oculus Rift, Leap Motions device and on the VTK open source library. An example of VR application for prosthesis design developed using FrameworkVR, is also described. Tests have been carried to validate the approach and the designed NUI and results reached so far are presented and discussed.

A number of pathologies impact on the way a patient can either move or control the movements of the body. Traumas, articulation arthritis or generic orthopedic disease affect the way a person can walk or perform everyday movements; brain or spine issues can lead to a complete or partial impairment, affecting both muscular response and sensitivity. Each of these disorder shares the need of assessing patient's condition while doing specific tests and exercises or accomplishing everyday life tasks. Moreover, also high-level sport activity may be worth using digital tools to acquire physical performances to be improved. The assessment can be done for several purpose, such as creating a custom physical rehabilitation plan, monitoring improvements or worsening over time, correcting wrong postures or bad habits and, in the sportive domain to optimize effectiveness of gestures or related energy consumption. The paper shows the use of low-cost motion capture techniques to acquire human motion, the transfer of motion data to a digital human model and the extraction of desired information according to each specific medical or sportive purpose. We adopted the well-known and widespread Mocap technology implemented by Microsoft Kinect devices and we used iPisoft tools to perform acquisition and the preliminary data elaboration on the virtual skeleton of the patient. The focus of the paper is on the working method that can be generalized to be adopted in any medical, rehabilitative or sportive condition in which the analysis of the motion is crucial. The acquisition scene can be optimized in terms of size and shape of the working volume and in the number and positioning of sensors. However, the most important and decisive phase consist in the knowledge acquisition and management. For each application and even for each single exercise or tasks a set of evaluation rules and thresholds must be extracted from literature or, more often, directly form experienced personnel. This operation is generally time consuming and require further iterations to be refined, but it is the core to generate an effective metric and to correctly assess patients and athletes performances. Once rules are defined, proper algorithms are defined and implemented to automatically extract only the relevant data in specific time frames to calculate performance indexes. At last, a report is generated according to final user requests and skills.

The computerization of manufacturing is one of the major challenges of the so-called fourth industrial revolution or Industry 4.0. Virtualization of the smart factory should provide real-time vision, control and monitoring of production through interactive dashboards and synchronization of data coming from different factory functions. The latter characteristics are particularly difficult to implement when the manufacturing core relies on traditional manual labour rather than on automation, as in the case of manual assembly. Monitoring or even controlling the manual work in real-time is extremely difficult to put into practice. Therefore, realizing the principles of Industry 4.0 in manual or semi-automatic labour contexts means developing new production control systems that involve the worker in the monitoring process without negatively affecting the production times or the psychological status of the workers. In particular, the authors propose a computer-aided production control framework based upon multimedia manuals and smart completeness control systems that can be used to implement the principles of Industry 4.0 in manual or semi-automatic work environments. This technology has been successfully tested in laboratory on the basis of a real industrial case study. The response of the testers has been positive and the outcomes in terms of increased product quality are promising.

Keywords: Cyber-physical systems , Industry 4.0 , Interactive electronic technical manuals , Production monitoring , Smart manufacturing

3D virtual reconstruction of human body parts is nowadays a common practice in many research fields such as the medical one, the manufacturing of customized products or the creation of personal avatar for gaming purpose. The acquisition can be performed with the use of an active stereo system (i.e., laser scanner, structured light sensors) or with the use of a passive image-based approach. While the former represents a consolidated approach in human modeling, the second is still an active research field. Usually, the reconstruction of a body part through a scanning system is expensive and requests to project light on the patient's body. On the other hand, the image-based approach could use multi-photo technique to reconstruct a real scene and provides some advantages: low equipment costs (only one camera) and rapid acquisition process of the photo set. In this work, the use of the photogrammetry approach for the reconstruction of humans' face has been investigated as an alternative to active scanning systems. Two different photogrammetric approaches have been tested to verify their potentiality and their sensitivity to configuration parameters. An initial comparison among them has been performed, considering the overall number of points detected (sparse point cloud reconstruction, dense point cloud reconstruction). Besides, to evaluate the accuracy of the reconstruction, a set of measures used in the design of wearable head-related products has been assessed.

This paper presents the implementation and investigation of a novel user centred method, adopted to design, develop and test a personal robot system, composed of a mobile robotic platform and a smart environment, for assisting people at home. As robots need to work closely with humans, novel interactive engineering design approaches are required to develop service robots that are adherent to end users' needs and that can be quickly employed in daily life. Particularly, this paper presents a methodology based on the simultaneous evaluation of dependability and acceptability, thus leading to an innovative approach for metrics and benchmarks that includes not only the main technical attributes of dependability, but also the parameters of acceptability, both implemented via a user-centered design and co-creative approach. Additionally, dependability and acceptability form the basis for defining standardized methodologies to test and evaluate robotic systems in dedicated experimental infrastructures (or robotic facilities), which are conceived to facilitate engineers in their studies and assessments.

Keywords: Acceptability , Companion robot , Dependability , Service robotics , User centred design

Nowadays, the adoption of virtual reality (VR) exhibits is increasingly common both in large and small museums because of their capability to enhance the communication of the cultural contents and to provide an engaging and fun experience to its visitors. The paper describes a user-centered design (UCD) approach for the development of a VR exhibit for the interactive exploitation of archaeological artefacts. In particular, this approach has been carried out for the development of a virtual exhibit hosted at the “Museum of the Bruttians and the Sea” of Cetraro (Italy). The main goal was to enrich the museum with a playful and educational VR exhibit able to make the visitors enjoy an immersive and attractive experience, allowing them to observe 3D archaeological artefacts in their original context of finding. The paper deals with several technical issues commonly related to the design of virtual museum exhibits that rely on off-the-shelf technologies. The proposed solutions, based on an UCD approach, can be efficiently adopted as guidelines for the development of similar VR exhibits, especially when very low budget and little free space are unavoidable design requirements.

Keywords: Human–computer interaction , User interface design , User-centered design , Virtual museum systems , Virtual reality

One of the most effective strategies that can be adopted to make successful cultural heritage expositions consists in attracting the visitors' attention and improving their enjoyment/engagement. A mid-air gesture-based Natural User Interface was designed, through the user-centric approach, for the navigation of virtual tours in cultural heritage exhibitions. In detail, the proposed interface was developed to “visit” Murgia, a karst zone lying within Puglia, very famous for its fortified farms, dolines, sinkholes, and caves. Including an “immersive” gesture-based interface was demonstrated to improve the user's experience thus giving her/him the sensation of “exploring” in a seamless manner the wonderful and rather adventurous sites of Murgia. User tests aimed at comparing the implemented interface with a conventional mouse-controlled one confirmed the capability of the proposed interface to enhance the user engagement/enjoyment and to make “more” natural/real, the virtual environment.

Keywords: Gesture vocabulary design , Natural user interface , User-centric approach , Virtual tour

Patients suffering from Spinal Cord Injury (SCI) can partially restore their walking function over ground and reduce of the secondary pathologies thanks to a frequent use of powered exoskeletons for robot-assisted gait. However, many of these devices require crutches to stabilize the body or to initiate the step. This could induce high loads on the shoulder joints, leading to shoulder pain and pathologies in SCI patients. This study presents a methodology to evaluate shoulder joints loads during robotic assisted gait, which was applied to an expert user of a Rewalk® exoskeleton. A pair of wireless instrumented crutches, designed by the authors[1], measure the crutches' forces and movements. A simplified mechanical model of the patient is then simulated in OpenSim to perform both inverse kinematic and inverse dynamic analysis. Such a system could be applied during the initial training of new users, to help guide both patient and therapist towards an optimal usage of the exoskeleton.

Keywords: Measurements , Rewalk , Robotic assisted gait , Upper limbs

Advanced driver assistance systems (ADASs) allow information provision through visual, auditory, and haptic signals to achieve multidimensional goals of mobility. However, processing information from ADAS requires operating expenses of mental workload that drivers incur from their limited attentional resources. The change in driving condition can modulate drivers' workload and potentially impair drivers' interaction with ADAS. This paper shows how the measure of cardiac activity (heart rate and the indexes of autonomic nervous system (ANS)) could discriminate the influence of different driving conditions on drivers' workload associated with attentional resources engaged while driving with ADAS. Fourteen drivers performed a car-following task with visual ADAS in a simulated driving. Drivers' workload was manipulated in two driving conditions: one in monotonous condition (constant speed) and another in more active condition (variable speed). Results showed that drivers' workload was similarly affected, but the amount of attentional resources allocation was slightly distinct between both conditions. The analysis of main effect of time demonstrated that drivers' workload increased over time without the alterations in autonomic indexes regardless of driving condition. However, the main effect of driving condition produced a higher level of sympathetic activation on variable speed driving compared to driving with constant speed. Variable speed driving requires more adjustment of steering wheel movement (SWM) to maintain lane-keeping performance, which led to higher level of task involvement and increased task engagement. The proposed measures appear promising to help designing new adaptive working modalities for ADAS on the account of variation in driving condition.

Emotional expression is an important human behavior, which enriches communication. Sensory organs play crucial role in emotional perception. Today, communication is mostly done via digital mediators, which dominantly address vision excluding other senses; therefore, communication becomes less affective. Wearable technology provides an intimate and continuous interaction with sensory organs. Hence, this technology can be used in order to make distant communication more affective by enabling multi-sensory interaction. This article presents a user-centered design practice on wearable products that simulate sensorial feedbacks (tactile, visual, and auditory) to express basic emotions. Three prototypes that transmit emotional messages were designed, built, and tested to observe user behavior. This article discusses how user experience obtained through the user test can be taken further to design new communication products, which can find solutions for different user needs.

Keywords: design practice , emotion , multi-sensory interaction , sensory perception , wearable technology

Eco-driving assistance devices are being introduced to reduce CO2 emissions, but the overall changes in the user behavior have not been sufficiently explored. While in-vehicle driver advanced systems are designed to support a single driving task (e.g. reducing emissions), they also imply the adoption of a different driving behavior and different driving attitudes in order to be efficient. Adopting for the first time a new driving style could affect driver's acceptance and undermine new technologies' efficacy. Purpose of the present research is to measure and evaluate the user's responses to first-time use of eco-driving assisting technology. Driver's performances in a virtual simulator were compared between experimental and a control group. The actual driving parameters and CO2 emissions were recorded and compared to the optimal eco-driving style calculated by CarMaker software. The cognitive costs of the new driving style were measured by changes in the modulation of autonomic nervous system and NASA-TLX workload scale. Acceptance of the assisted driving style and general eco-friendly attitudes were analyzed by self-reported measures. Results show that being exposed for the first time to eco-driving technology produces a reduction of cumulate fuel consumption only due to speed reduction, and not to changes in the driving style parameters, as recommended by the assisting software. Overall CO2 emissions of eco-driving group were not different from the control group. Rather, the first time use of the eco-driving assistance increases perceived fatigue and the physiological cardiac autonomic balance related to increased workload over time. These difficulties show that eco-driving style cannot be simply adopted by following the assistance device indications. It seems rather a process, which requires specific support during in the first driving-interaction with eco-driving technology. The design of assistance device that aims to change the driving style, could benefit from the measurement of the user's workload to avoid primacy effect that potentially undermine technology efficacy in supporting user-sustainable behaviors.

Keywords: Acceptance , Assistance technologies , CO2 emissions , Human-machine interaction , Pro-environmental behavior , Workload

This research aims to design and develop an innovative system, based on an olfactory display, to be used for investigating the directionality of the sense of olfaction. In particular, the design of an experimental setup to understand and determine to what extent the sense of olfaction is directional and whether there is prevalence of the sense of vision over the one of smell when determining the direction of an odor, is described. The experimental setup is based on low cost Virtual Reality (VR) technologies. In particular, the system is based on a custom directional olfactory display, an Oculus Rift Head Mounted Display (HMD) to deliver both visual and olfactory cues and an input device to register subjects' answers. The VR environment is developed in Unity3D. The paper describes the design of the olfactory interface as well as its integration with the overall system. Finally the results of the initial testing are reported in the paper.

In this paper, we present the development of an application that allows us to simulate the multisensory experience of tasting a glass of wine. To this end, technologies for the sense of touch, sight, hearing, and smell have been integrated, creating an interactive multi-sensory experience. The user, after picking up a glass, activates an application in which he is guided by a virtual sommelier to make a tasting, and he is able to perceive the multi-sensory experience of the wine tasting experience. The paper describes the application and its potential use in marketing.

Keywords: Multisensory product experience , User experience , Virtual reality (VR)

Despite the large number of studies on the multisensory aspects of tactile perception, very little is known regarding the effects of visual and auditory sensory modalities on the tactile hedonic evaluation of textures, especially when the presentation of the stimuli is mediated by a haptic device. In this study, different haptic virtual surfaces were rendered by varying the static and dynamic frictional coefficients of a Geomagic® Touch device. In Experiment 1, the haptic surfaces were paired with pictures representing everyday materials (glass, plastic, rubber and steel); in Experiment 2, the haptic surfaces were paired with sounds resulting from the haptic exploration of paper or sandpaper. In both the experiments, participants were required to rate the pleasantness and the roughness of the virtual surfaces explored. Exploration times were also recorded. Both pleasantness and roughness judgments, as well as the durations of exploration, varied as a function of the combinations of the visuo-tactile and the audio-tactile stimuli presented. Taken together, these results suggest that vision and audition modulate haptic perception and hedonic preferences when tactile sensations are provided through a haptic device. Importantly, these results offer interesting suggestions for designing more pleasant, and even more realistic, multisensory virtual surfaces.

Keywords: Haptics , hedonic touch , multisensory interaction , virtual surface

Road accidents represent the primary cause of death among young drivers. To understand the emerging issue of young drivers' involvement in traffic accidents abroad, risk-taking behaviors were investigated in familiar and unfamiliar driving situations. Twenty-two young Chinese drivers completed a road regulation test followed by a simulated test drive. The number of traffic violations and accidents in familiar and unfamiliar driving intersections were correlated to road regulation knowledge, risk perception scores and to self-assessment of driving skills. Significant number of mistakes was found in risk-taking situations, regardless of the familiarity of the situation, especially for drivers that presented high ratings of self-assessed driving skills. Results show that risk-taking behaviors while driving in unfamiliar conditions are mediated by psychological factors, like self-assessment of being a good driver, more than the actual knowledge of road regulation rules. Implications for international driving can be considered for future research development.

Keywords: Driving skills , International driving , Knowledge of traffic laws , Risk perception , Road intersection , Road violations and accidents , Young drivers

Aging societies have an extended need for transportation solutions that enhance elderly's independence. However, the solutions needed are as manifold as the elderly's lifestyles are. This study uses Usercentred Design principles as a structuring tool to manage this complexity of requirements. By not just focusing on specific functionalities but also reflecting product life cycle and usage context, new types of requirements can be revealed. Through a case study, this article shows how a participatory design approach can lead to integrated solutions that better fit the user's needs.

Keywords: Co-design , Human centred design , Integrated product development , Requirements management , Teamwork

The study of ergonomics and (dis)comfort is a major topic of interest to scientific literature since the introduction of ISO 11228. Over the past 30 years, researchers have attempted to understand the mechanisms underlying perceptions of (dis)comfort for a seated subject. Three main factors are recognized as paramount for the comfort performance of a seat: human body posture, pressure at interface, and load distribution on the contact area; this study investigates the relationships between them and examines their significance for (dis)comfort perception. Physiological factors are known to play a role in (dis)comfort perception, and we consider these as a consequence of the three main parameters above. An explanation is given for this hypothesis. Experimental tests were conducted using a school chair with a rigid seat pan and no armrests for reducing the number of factors of influence. Conclusions show the levels of correlation between acquired information and perceived (dis)comfort.

Keywords: Comfort , Posture , School furniture , Seating , User experience

In a highly competitive global aviation environment, European regional aircraft requires continuous improvements in cabin comfort. This paper describes the design for comfort process proposed in an industrial research project, aimed at the definition of innovative design approaches to measure the affective impact on a potential user when living in and interacting with the cabin. The study is performed in the framework of CASTLE (CAbin Systems design Toward passenger welLbEing). CASTLE is a project granted under the Horizon 2020 EU's research programme in the framework of the Clean Sky 2 initiative. Requirements and recommendations for the comfort aspects to be taken into account to develop a regional aircraft's cabin were provided by Leonardo's Aircraft Division. The methodological approach is set up in a Virtual / Augmented Reality Environment for the definition of a Human Centered Response Model for the design for comfort of regional aircraft interiors. In this context, special attention has been paid to the improvements that can be brought to the cabin interiors, and specifically to the experience that passengers can live in the aircraft of the future. The main objective of the project is to conceive, develop, prototype and test cabin interiors solutions following a HCD (Human Centered Design) methodology. The paper analyzes the approach toward the definition of the design for comfort according to the considered cabin items and design requirements. The proper comfort metrics are selected and linked to an experimental protocol analysis for their assessment. A Virtual Reality environment has been set up to support the comfort assessment in aircraft cabin interiors, from their preliminary design.

Keywords: Aircraft interiors Design , Comfort , Emotional Design , Human Centered Design , Virtual Reality

Feature-based modeling and feature recognition algorithm are state of the art technologies, mainly used to favor the integration and exchange of data between design and manufacturing phases. This paper aims to investigate the possibility to extend the use of the feature recognition as a means for the prevention of ergonomics issues during the manual assembly phase, such as Work-related Musculo-Skeletal Disorders (WMSDs). Starting from the features analysis of a 3D product model, the proposed five steps method allows preventively identifying potential ergonomics issues. The main novelty of this study is related to the correlation between design tools, product virtual representations (e.g. 3D models), assembly and ergonomics aspects. Results obtained with two case studies, a cooker hood and a tool-holder carousel, confirm the usefulness of the proposed method in helping designers to prevent potential ergonomics issues for operators involved in the assembly phase.

Keywords: Ergonomics , Feature recognition , Manual assembly , Virtual product model , Work-related Musculoskeletal Disorders