Human factors and ergonomics

The interest of people working in rehabilitation towards the possibilities offered by Virtual Reality (VR) technologies is growing in years. Through VR technologies, rehabilitation can become more engaging with respect to traditional methods, since exercises can be performed in different simulated scenarios. They can be adapted on the basis of patient's requests, and can be easily modified to have growing difficulties, according to the rehabilitation progresses. Furthermore results can be collected and monitored, even remotely, if necessary. The paper describes the development and testing of a set of exercises in a multimodal VR environment for upper limb rehabilitation. The VR environment includes technologies addressing three senses: vision, hearing and touch. The patient is asked to grab and move a number of objects in an ecologically valid environment, which corresponds to a household scenario. While s/he performs the exercises, object trajectories are recorded in order to be analyzed later on. The development as well as a preliminary testing activity are reported in the paper.

This paper presents a new concept of a desktop tangible shape display for virtual surface rendering. The proposed system is able to represent in the real environment the shape of a digital model of a product, which can be explored naturally through a free-hand interaction. Aim of the shape display is to allow product designers to explore the rendered surface through a continuous touch of curves lying on the product shape. Ideally, the designer selects curves, which can be considered as style features of the shape, on the shape surface, and evaluates the aesthetic quality of these curves by manual exploration. In order to physically represent these selected curves, a flexible surface is modelled by means of servo-actuated modules controlling a physical deforming strip. The behaviour of the strip is controlled by acting on the position and rotations of a discrete number of control sectors. Each control sector is controlled by a module, which is based on an absolute positioning approach and equipped with five degrees of freedom. The developed system is able to manage the elastic behaviour of the strip in terms of bending, twisting and local tangency. The tangency control allows us to manage the local tangency of the strip to the rendered trajectory, thus increasing the accuracy of the representation. Moreover, a preliminary second version of the module is presented, which has been designed so as to allow the control sectors to slide on the strip. Thanks to this feature, it will be possible to place the control sector in a given point of the trajectory, such as point of maximum, point of minimum or inflection points. The device is designed to be portable, low cost, modular and high performing in terms of types of shapes that can be represented. A prototype equipped with three modules has been developed in order to evaluate the usability and the performances of the display.

The study of experience in the interaction with goods, both physical and virtual, is consistently affected by the role of the context in which this interaction occurs. The paper analyses the global problem starting from three independent variables: product, people and context, and focuses on the analysis of single couples of independent variables: goods-person, goodscontext and person-context. From this analysis it is derived a general framework oriented to the experimenting and validation of the use of Virtual Prototyping to optimize the perceived value of products To-Be.

The sense of smell has a great importance in our daily life. In recent years, smells have been used for marketing purposes with the aim of improving the person's mood and of communicating information about products as household cleaners and food. However, the scent design discipline can be also applied to any kind of products to communicate their features to customers. In the area of Virtual Reality several researches have focused on integrating smells in virtual environments. The research questions addressed in this work concern whether Virtual Prototypes, including the sense of smell, can be used for evaluating products as effectively as studies performed in real environments, and also whether smells can contribute to increase the users' sense of presence in the virtual environment. For this purpose, a Virtual Reality experimental framework including a prototype of a wearable olfactory display has been set up, and experimental tests have been performed.

Emotional expression is an important human behaviour, which enriches communication. Sensory organs play crucial role in emotional perception. Today communication is mostly done via digital mediators, which dominantly address to vision excluding the other senses; therefore, communication becomes less affective. Wearable technology can appeal to sensory organs from very close distance due to its intimate interaction with human body. Hence, this technology can be used in order to make distant communication more affective by enabling multisensory interaction. This paper represents a user-centred 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 behaviour. This paper discusses how user experience obtained through the user test can be taken further to design new communication products.

Keywords: Design practice , Emotion , Sensory perception , Wearable technology

Beyond ergonomic measurements, the study of human movements can help designers in exploring the rich, non-verbal communication of users' perception of products. This paper explores the ability of human gestures to express subjective experiences and therefore, to inform the design process at its early stages. We will investigate the traditional techniques used in the Experience Design domain to observe human gestures, and propose a method to couple Experience-driven design approach with Motion Capture technique. This will allow integrating qualitative user observations with quantitative and measurable data. However, the richness of information that Motion Capture can retrieve is usually inaccessible for designers. This paper presents a method to visualize human motion data so that designers can make sense of them, and use them as the starting point for concept generation.

Keywords: Body Tracking , Concept design , Data visualization , Motion Capture , User experience

The sense of smell has a great importance in our daily living: today pleasant odors are used to elicit positive emotions in users. In the marketing area, a lot of works have been done concerning the use of odors for communicating information for products as household cleaners and foods. In the area of Virtual Reality (VR) several researches have focused in presenting odors in virtual environments. The introduction of odors simulation in virtual environment could represent an easy and flexible tool for evaluating industrial products characteristics. This research work aims at evaluating in which way odors can influence the users' evaluation of products and if studies on the influence of odors on the users' evaluation of products in a VR environment and in a real environment can be comparable. For this purpose, an experimental framework has been defined, a wearable olfactory display has been developed and experimental testing sessions have been performed.

Keywords: Multisensory interaction , Olfactory display , Product evaluation , User experience

The definitions of methods and tools used to evaluate how workers perceive the comfort during their activities remains an “open” problem at this time. Many researchers have dealt with that problem in the last twenty years, focusing their efforts primarily on the automotive sector and on VDT workstation comfort. This paper analyzes how workers position themselves at workstations used in industrial processes that sew together the edges of mattresses. The aim of the analysis is to determine whether workers can position themselves in ways that allow them to carry out activities in simple and economical ways. The Strain Index was used to identify the most critical and risky work phases in order to evaluate workers' risk of biomechanical overload. The OCRA checklist was used to evaluate the overall risk level associated with repeated completions of the total cycle of work and to develop a virtual-postural analysis to evaluate workers' perceived levels of discomfort. For the virtual-postural analysis, DELMIA® software was used to virtually model a workstation, and records of activities and the postures associated with various repetitive actions were gathered in a non-invasive manner with cameras and video cameras. CaMAN® software developed by the researchers from the Department of Industrial Engineering in Salerno (Italy) was used to calculate comfort indexes. An analysis of the comfort indexes was used to make as the basis for suggestions to correct workers' postures and for plans to redesign the workstations in order to improve ergonomics and allow workers to perceive them as more comfortable.

Keywords: Comfort evaluation criteria , Digital human modeling , Ergonomics , Non-invasive postural analysis , Redesign

What are the new trends in research for comfort evaluation and the objective and predictive techniques for quantifying and qualifying comfort perception by humans? This paper has attempted to answer this question in a wide literature review, whereby it is possible to highlight many partial aspects that have been studied successfully. Just a few researchers [1–3] have studied the problem of comfort perception and evaluation under a wider point of view. Nevertheless, some aspects seem not to have yet been taken into account. In a previous paper, the authors extended the Vink–Hallbeck model to build a comfort perception/evaluation matrix in which four kinds of comfort related to different humans' perception were studied and linked to the whole environment's characteristics. In the resultant perception-scheme and in the proposed “fusion rule” (for different kinds of perceived comfort/discomfort), one aspect that played a fundamental role in the final comfort/discomfort perception/evaluation was expectation. Expectation due to preconceived data (acquired or formed in the users' minds) and the influence of the working environment, can act in terms of additive or subtractive factor in the comfort experience by altering the final comfort/discomfort perception and changing the subjective comfort/discomfort evaluation. This paper presents the results of expectation influence analysis on comfort evaluation. Using the placebo effect, authors conducted a wide experimental test with a wide sample of users, asking them to use and evaluate two identical mattresses that were dressed and described as two different products (the first one as a very cheap mattress and the second one as a high-level and expensive mattress). Differences between subjective evaluations have been statistically processed and correlated to anthropometric parameters to individuate and understand the role of expectation.

Keywords: Cognitive , Comfort evaluation , Expectations , Mattress , Physiological and environmental comfort , Postural

Blind people are typically excluded from equal access to the world's visual culture, thus being often unable to achieve concrete benefits of art education and enjoyment. This is particularly true when dealing with paintings due to their bi-dimensional nature impossible to be explored using the sense of touch. This may be partially overcome by translating paintings into tactile bas-reliefs. However, evidence from recent studies suggests that the mere tactile exploration is often not sufficient to fully understand and enjoy bas-reliefs. The integration of different sensorial stimuli proves to dramatically enrich the haptic exploration. Moreover, granting blind people the possibility of autonomously accessing and enjoying pictorial works of art, is undoubtedly a good strategy to enrich their exploration. Accordingly, the main aim of the present work is to assess the feasibility of a new system consisting of a physical bas-relief, a vision system tracking the blind user's hands during “exploration” and an audio system providing verbal descriptions. The study, supported by preliminary tests, demonstrates the effectiveness of such an approach capable to transform a frustrating, bewildering and negative experience (i.e. the mere tactile exploration) into one that is liberating, fulfilling, stimulating and fun.

Keywords: Blind people , Cultural heritage , Hand tracking , Human-computer interaction

In Human-Machine Interface (HMI) design, several parameters have to be correctly evaluated in order to guarantee a good level of safety and well-being of users (humans) and to avoid health problems like muscular-skeletal disease. ISO Standards give us a good reference on Ergonomics and Comfort: ISO 11228 regulation; it deals with qualitative/quantitative parameters for evaluating Postural Ergonomics, using a "Postural Load Index", in push/pull, in manual loads' lifting and carrying and in repetitive actions; those parameters can represent the Ergonomics level of examined posture. While bibliographic references suggest different methods to make ergonomic evaluation like RULA, LUBA and REBA, the state of the art about comfort/discomfort evaluation shows the need of an objective method to evaluate "effect in the internal body" and "perceived effects" in several schemes of comfort perception like Moes', Vink & Hallback's and Naddeo & Cappetti's ones; postural comfort is one of the aspect of comfort/discomfort perception and this paper proposes a new quantitative method for evaluating this aspect of comfort, based on anthropometric parameters and upper limbs posture. The target of this paper is to present and test a "general purpose" method of comfort-measurement that can be applied to different industrial cases: in workspace environments, in automotive passenger compartments, in aeronautic cockpit or in industrial assembly lines. Relevance to industry: The method presented in this paper may allow industrial designers to provide an assessment of products' perceived comfort in the early stage of the product development process by making a posture-based quantitative evaluation; it also allows designers to make a comfort driven redesign of existing products' configuration for improving and innovating them.

Keywords: Comfort evaluation , Ergonomics , Industrial design , Postural analysis

The monitoring of vital parameters for athletes of all disciplines is becoming more and more essential, to improve performances and to ensure a constant control of athletes' physical conditions, thus preventing health risks and injuries. However, especially in amatorial competitions, the low available budget limits leads to the use of inexpensive and thus ineffective instrumentation. In this paper, a low-cost system, based on a commercial smartdevice, for monitoring purposes in the context of amatorial car races is proposed. A single-lead electrocardiographic trace, body temperature, and driver acceleration profile are simultaneously acquired, locally stored and preprocessed, and periodically sent to a cloud service, allowing data sharing and remote processing. Experimental tests operated by means of a Formula SAE car in a test track have demonstrated the effectiveness of the proposed approach for the acquisition of important data to evaluate the degree of stress of a driver during the race.

Keywords: amatorial car race , smartphone-based system , Vital parameters monitoring

The present work describes the interactive prototype and the preliminary evaluation results of a tool dedicated to the light General Aviation pilot's community. The tool's interface has been developed through an Android tablet application and aims at supporting the pilots in the task of staying “well-clear” from the surrounding traffic by presenting them the long-term prediction of the flights. The initial results and the approach of a heuristic evaluation conducted with five experts coming from the fields of user-experience, aviation and automotive are discussed along with the improvements in the design of the user-interface focusing on the trajectory depictions.

Keywords: Heuristic evaluation , Light general aviation , Trajectory prediction visualization , User-interface design

A correct recognition of nonverbal expressions is currently one of the most important challenges of research in the field of human computer interaction. The ability to recognize human actions could change the way to interact with machines in several environments and contexts, or even the way to live. In this paper, we describe the advances of a previous study finalized to design, implement and validate an innovative recognition system already developed by some of the authors. It was aimed at recognizing two opposite emotional conditions (resonance and dissonance) of a candidate to a job position interacting with the recruiter during a job interview. Results in terms of the accuracy, resonance rate, and dissonance rate of the three new optimized neural networkbased (NN) classifiers are discussed. Comparison with previous results of three NN classifiers is also presented based on three single domains: facial, vocal and gestural.

Keywords: Facial/vocal/gestural features , Job interview , Neural networks and support vector machines , Nonverbal emotional recognition

Designing a multi-user adaptive interface means designing for diversity in end-users and contexts of use, and implies making alternative design decisions, at various levels of the interaction project, inherently leading to diversity in the final design outcomes. Nowadays Adaptive User Interfaces (AUIs) is becoming one of the major objectives addressed by Human Computer Interaction research. The present study provides an overview about the methods currently applied to the definition and development of AUIs. In order to study and develop adaptive user interfaces with the purpose to guarantee socialization, safety and environmental sustainability in a domestic day-by-day living space, a new method of holistic and adaptive user interface is proposed to support the modeling of information related to the user and the context of the interaction. In order to generate the user profiles, subjects older than 40 years with different levels of technology affinity will be considered. These prototypes will be tested through different use cases in the context of smart home environments. The final goal is to produce smart objects and consumer goods able to automatically satisfy the different skills, abilities, needs and human preferences, in an environment where each solutions address different individuals.

In order to study and develop adaptive user interfaces with the purpose to guarantee socialization, safety and environmental sustainability in a domestic day-by-day living space, a new method of holistic and adaptive user interface is proposed to support the modelling of information related to the user and the context of the interaction to generate the user profiles, subjects older than 40 years with different levels of technology affinity have been considered. The new adaptive user interfaces prototypes will be tested through different use cases in the context of smart home environments.

Keywords: Adaptive interfaces , Design for AAL , User interfaces , User-centered design

In the last years introducing measures to face age discrimination and increasing work safety in production environments have become crucial goals. The present research proposes an innovative user interface exploiting Augmented Reality techniques to support frail people, mainly elderly, in everyday work on complex automated machines. It adapts its functionalities according to the user skill, tasks, age, and cognitive and physical abilities thanks to a set of knowledge-based configuration rules. A case study is described to illustrate the methodology to manage the complexity of configuration rules and the resulting developed platform.

Keywords: Accessibility , Adaptation , Augmented reality , Human-computer interaction , User-centred design

In this paper, the development and the experimental testing phases of an innovative assistive device for hand disabilities are presented. This robotic device is based on an parallel kinematic chain applied to a single phalanx architecture and it is designed to be extremely portable to easily assist people with physical disabilities in their everyday lives. Focusing on patients with hand opening disabilities, the authors have developed a model-based methodology which starting from the motion capture of the patient fingertip trajectories is able to define the mechanism that better fits with such trajectories. The authors have validated the proposed innovative mechanism by developing a portable Hand Exoskeleton System (HES) prototype and performing a suitable preliminary testing campaign. The testing phase of the real prototype on a group of patients is currently ongoing.

Keywords: Exoskeletons , Joints , Kinematics , Mathematical model , Prototypes , Solid modeling , Trajectory

In this research work, the authors developed and tested a low cost wearable and portable hand exoskeleton to assist people with physical disabilities in their everyday lives. Focusing on hand opening disabilities, the proposed actuated orthoses could support and enable daily gestures such as shacking hands or grasping objects. The Hand Exoskeleton System (HES) prototype is based on a cable-driven architecture applied to a single-phalanx mechanism. The preliminary prototype of the system has been successfully built and is currently under testing with a patient to verify its performance from a patient viewpoint.

Human Robot Collaboration (HRC) have proved to be effective if compared to traditional hybrid automation in assembly tasks, especially when human-like sensitivity and high quality are required. However, a rigorous engineering design is mandatory in order to successfully apply HRC to Industry. Academy and Industry are asked to jointly work for exploiting the technical opportunities given by robots and humans. Scientific literature often describes the application of HRC in manufacturing but rarely presents systematic engineering design approaches. The present paper investigates and describes the systematic design of a HRC workcell for assembling bio-medical products. Moreover, productivity and profitability of the developed solution are evaluated and discussed.

Keywords: Assembly , Biomedical products , Human-Robot Collaboration