Human factors and ergonomics

Interactive data visualization plays a crucial role in the interpretability of large datasets. Virtual reality offers unique advantages in exploring data, beyond traditional 2-D views. This article presents a set of interaction artifacts designed for analyzing and interpreting complex datasets through immersive 3-D graph visualization and interaction. Our system makes complex datasets easier to work with by offering a wide range of visual customization tools and intuitive methods for selection, manipulation, and filtering. It also provides a cross-platform, collaborative environment that can be accessed by remote users through traditional computers, drawing tablets, and touchscreen devices.

Keywords: Data visualization , Large dataset , Three dimensional computer graphics , Visualization

An area of interest in orthopaedics is the development of efficient customized neck orthoses, considered that pathologies which affect the neck area are widespread. Advanced acquisition and modelling approaches combined with Additive Manufacturing (AM) can potentially provide customized orthoses with improved performance and complexity. However, in the design of these devices, besides functional and structural requirements, benefit and comfort of the patient should be a main concern, in particular, at the early stage of design during the acquisition of the body's part, and while using the printed orthosis. In this paper, a scanning system with three sensors was developed which allows a fast, about 5 s, and accurate acquisition of the neck area with minimum discomfort for the patient. A neck orthosis with a ventilation pattern obtained by Topology Optimization (TO), lightened by about 35%, was also established. In fact, a main role for comfort is played by the ventilation pattern which contributes both to lightness and breathability. Its structural and comfort performance was evaluated in comparison with an orthosis with a ventilation pattern configured by Voronoi cells. Structural assessment was carried out by means of finite element analysis under main loading conditions. An evaluation of neck temperatures in relation to wearing 3D printed prototypes, manufactured with Hemp Bio-Plastic® filament, was finally conducted by means of a thermal imaging camera. TO orthosis prototype showed a better performance regarding thermal comfort, with a maximum increase of neck temperature less than 1 °C, which makes the proposed configuration very promising for user's comfort.

Keywords: Additive manufacturing , CAD , Orthosis modelling , Reverse engineering , Thermal comfort , Topology optimization

A way of presenting information in visual representations of technical systems influences the progress and the outcome of the engineering design process. Consequently, improving the means by and through which information is utilised during the process is one suggested approach to advancing engineering design. Engineers' interaction with visual representations of technical systems is mainly visual and virtual. Although such interactions are cognitively complex, little is known about cognition (mental information processing) underlying the utilisation of design information during engineering design. To narrow the research gap, this study explores how visual representations of technical systems affect engineers' brain activity while generating computer-aided design (CAD) models based on them. More precisely, the brain activity of 20 engineers is captured and analysed using electroencephalography (EEG) during the visuospatially-intensive design tasks of CAD modelling in two conditions; when technical systems are presented with orthographic and isometric projections in technical drawings. The results imply the sensitivity of engineers' brain activity in CAD modelling to the visual representation from which a technical system is interpreted. In particular, significant differences are found in theta, alpha, and beta task-related power (TRP) over the cortex when interpreting the technical drawings and CAD modelling from them. Furthermore, the results reveal significant differences in theta and alpha TRP when considering the individual electrodes, the cortical hemispheres, and the cortical areas. In particular, theta TRP over the right hemisphere and the frontal area seems essential in distinguishing neurocognitive responses to the orthographic and isometric projections. As such, the conducted exploratory study sets the foundations for exploring engineers' brain activity while performing visuospatially-intensive design tasks, whose segments are relatable to the aspects of visuospatial thinking. Future work will explore brain activity in other design activities that are highly visuospatial, with a larger sample size and an EEG device of a higher spatial resolution.

Keywords: brain , cognition , electroencephalography , engineering , physiology

This paper presents an EEG (Electroencephalography) study that explores the correlation between the EEG variation across design stages and the quality of the design outcomes. The brain activations of 33 volunteers with engineering backgrounds were recorded while performing a design task using a morphological table to develop an amphibious bike. The EEG variations from the analysing/selecting stage to the illustrating stage were analysed based on the EEG frequency band and channel sets. A significant correlation between the detail level of the design outcome and the power variation mode was observed in theta, alpha and gamma bands, each involving different channel sets. Compared to the assessment results from two evaluators, using EEG variations as a proxy of the detail level of the design outcome could reach a maximum accuracy of 0.727, precision of 0.765, and recall of 0.889. These results also provide suggestions on the selection of the frequency bands and channel sets to achieve better prediction performance according to each metric.

Keywords: Design cognition , Design Quality , Electroencephalography , Human behaviour in design , Research methodologies and methods

As an initial step towards a better understanding of cognitive load in computer-aided design (CAD), the herein presented study investigated cognitive load imposed on 24 mechanical engineers during two CAD modelling tasks of intentionally different complexity levels. The cognitive load has been rarely studied in the CAD context, which resulted in the lack of understanding if and how the EEG-based indicators available from the literature reflect the changes in cognitive load imposed on engineering designers in CAD activities. Therefore, cognitive load was measured and analysed using three EEG-based indicators to explore insights that might be obtained from them. The initial analysis revealed different cognitive load results from the employed indicators for the same EEG data. In addition, the study implies that the cognitive load results obtained through the used indicators are only partially coherent with the CAD modelling task complexity. Hence, the results imply that the chosen EEG-based indicator matters when measuring and analysing cognitive load in CAD modelling tasks and that its adjustment for CAD context might be needed.

Keywords: Cognitive load , Complexity , Computer Aided Design (CAD) , Design cognition , Electroencephalography

This chapter presents selected case studies showcasing the design and testing of user experiences through prototypes created with eXtended Reality (XR) technologies. These case studies were developed by students participating in the Virtual and Physical Prototyping course at the School of Design, Politecnico di Milano. The projects assigned to student teams aimed to create prototypes prioritizing user interaction and experience, such as apps connecting young people with nature or aiding language learning. The students followed a simplified product development process, starting with defining the target audience and requirements, followed by concept development and design execution, and appropriate XR technologies selection for the implementation. The chapter presents a set of guidelines that outline this simplified product development process for crafting XR application prototypes. Subsequent chapters showcase how these guidelines were applied by the students in their respective case studies.

Keywords: Product design , Product development , Software prototyping

This chapter presents three examples demonstrating the advantages of multisensory experiences in eXtended Reality applications. The first case study involves a training application designed to familiarize users with laboratory machinery, incorporating the senses of sight, hearing, and smell. The second case study concerns the utilization of multisensory experiences in Augmented Reality to facilitate language learning and enhance the exploration of a new city. The third one concerns a multisensory application including visual components, sounds, and odors for learning music.

Keywords: Augmented reality

This chapter provides an overview of the fundamental concepts, methodologies, and interdisciplinary nature of User eXperience Design (UX Design). UX Design is a multidisciplinary field that focuses on creating meaningful and valuable experiences for users. This chapter explores the concept of experience and its relation to perception, emotions, and individual needs. It discusses the User Centered Design (UCD) philosophy, which places the user at the center of the design process. The chapter outlines the four main phases of the UCD process: specifying the user and context of use, specifying user requirements, producing design solutions, and evaluating designs. It emphasizes the importance of user participation throughout the design process and highlights various qualitative and quantitative methods used in each phase. The chapter also introduces different models and frameworks, including the Double Diamond model and the Design Thinking model, which provide structured approaches to problem-solving and innovation. Additionally, it addresses the misconception that UX Design is limited to digital products and emphasizes the broader scope of the field, encompassing both digital and physical interactions.

Keywords: Behavioral research , Product design

This chapter presents three examples that demonstrate the effective integration of Reality and Virtuality, resulting in captivating applications that significantly enhance and improve the user experience through their seamless combination. The primary objective of the first case study is to explore and examine various methods of fostering connections among individuals through the utilization of Augmented Reality technology for collaborative art experiences. The second case study focuses on proposing a connection between humans and plants through Virtual Reality to enhance mental and physical well-being, as well as overall quality of life. The third case study focuses on leveraging Augmented Reality technology for maintenance operations.

Keywords: Arts computing , Augmented reality , User experience

This chapter provides an overview of eXtended Reality (XR), a term that encompasses technologies such as Virtual Reality (VR), Augmented Reality (AR), and Mixed Reality (MR). XR allows the real world to be enriched with virtual data, objects, and information, offering varying levels of immersion and interaction. The chapter explores the components of XR and discusses classification frameworks, including Milgram's Reality-Virtuality Continuum and the 3I model. It further delves into the developments and technologies of VR, highlighting stereoscopic vision, VR headsets and immersive walls. The chapter also explores AR, its accessibility through everyday devices, and its applications. The importance of considering all sensory modalities for creating immersive XR experiences is emphasized, and the role of multimodal interaction in enhancing user experiences is discussed. The chapter highlights the significance of a multisensory approach in achieving a sense of presence and explores examples of early immersive and multisensory technology. Finally, it discusses the impact of touch in human interaction and the incorporation of tactile sensations in VR applications, as well as of olfaction, which plays a significant role in human perception and memory, as certain smells can evoke strong emotional responses and trigger vivid recollections of past experiences. Incorporating odors into XR applications can enhance the overall sense of presence and realism by providing users with scent cues that align with the virtual environment. Olfactory displays are devices that release specific odors or scents to accompany virtual content.

Keywords: Behavioral research , Display devices , Mixed reality , Odors , Stereo image processing

This chapter discusses the complex process of introducing new products to the market and the challenges involved. It highlights the importance of understanding user needs, both explicit and latent, in order to create products that meet customer requirements and provide a positive user experience. Failure to properly analyze user needs can lead to product dissatisfaction and costly design changes later in the process. The chapter emphasizes key requirements for new products, including style, functionality, quality, safety, and sustainability, and also explores the cost of design changes and the significance of addressing design problems early in the development process. It explains how the cost of fixing issues increases as the product development progresses and emphasizes the importance of timely validation and testing to minimize the cost impact of changes. Prototyping is identified as a valuable tool in the product development process for evaluating user needs and refining design concepts. It explains the iterative nature of prototyping and its role in eliminating unfeasible or undesirable solutions. The chapter discusses the purposes of prototypes, such as experimentation, learning, communication, testing, exploration, education, and research. Different types and scopes of prototypes are explained, including comprehensive and focused prototypes, as well as the concept of fidelity, which measures the degree of resemblance between the prototype and the final product. The chapter also provides an overview of various prototyping resources, such as sketches, wireframes, physical models, 2D and 3D renderings, interactive prototyping, and virtual prototyping using eXtended Reality technologies.

Keywords: Iterative methods , Product design , Three dimensional computer graphics

This chapter provides insights into the dynamic nature of product design and the key factors influencing consumer perceptions and preferences in the modern era. It explores the multidimensional field of product design, which combines engineering, design, psychology, and other disciplines to create new products. It emphasizes the importance of understanding the concept of a product, which comprises both tangible and intangible elements that provide value to consumers. Today's products are complex systems that constantly evolve due to advancing technology and the demands of customers. The chapter discusses the shift in customer preferences towards personalized products and the challenges faced in manufacturing customized items, and highlights the three primary attributes of products: functions, style, and usability. The chapter also emphasizes the increasing importance of customization and personalization in product design, and explores the significance of efficient product development processes to meet market demands and user expectations.

Keywords: Advancing technology , Consumer perception , Consumers preferences , Customer preferences

Product development stages are typically characterized by different forms of representations and degrees of specification, which potentially affect user\'s perception and evaluation. These effects are worth investigating more closely also because of the growing relevance of new technologies such as Virtual Reality (VR) in the design field. The objective of this paper is to elucidate the mutual relations between forms of representation, visual behaviour, and people\'s evaluations. The focus is on differences between virtual and physical prototypes. In the illustrated experiment, participants visited a tiny house in an immersive VR (360° images acquisition). The results were compared with a past experiment where the physical prototype of the same product was similarly evaluated. The dwell times on Areas of Interest (AOIs) pertaining to the tiny house were compared and correlated to variables concerning subjective evaluations. The results show just a few similarities of visual exploration in terms of gazed AOIs. Substantial differences in terms of how the duration of gazing affects evaluations have been found too. The larger number of significant correlations between observations and evaluations in the virtual exploration emerged.

Keywords: Case study , Evaluation , Prototype , Representation form , Virtual reality

Among the main features of Industry 4.0, digitization and the evolution of the human-machine interaction occupy a central role. These concepts are transferring even in the health domain, moving toward Healthcare 4.0. The new concept of Industry 5.0 further promotes the human-centric perspective focusing on the consideration of human factors. In this context, training for workers, both in the industry and in the healthcare sectors, needs to be strongly human-centred to be efficient and effective. This paper refers to simulation-based training and aims to provide a transdisciplinary framework for the simulation assessment from the learners' perspective. The final scope is to outline a set of data-driven guidelines for the simulation optimization and redesign, throughout a human-centred approach, aiming to improve the workers' performance and the overall learning process, considering the physical, cognitive, and emotional conditions. The proposed method is suitable for each kind of training (both traditional and with the use of virtual reality/augmented reality systems) and relevant for every sector. Two different use cases are presented, respectively referring to the healthcare and industry fields, proposing a unique assessment protocol. The healthcare use case considered the low-fidelity simulation of lumbar puncture, while the industrial use case referred to the replacement of the engine oil filter on tractors. Although the great differences between the content of the use cases, the results obtained about performance as well as cognitive and emotional states are close enough to define a common set of guidelines to redesign and optimize the simulation-based training.

Keywords: Design optimization , Ergonomics , Healthcare 4.0 , Human Factors , Industry 4.0 , Simulation-based training

The population aging phenomenon has been increasing in the last years and will become prevailing in the future ones. In the era of Healthcare 4.0, the application of information and communication technologies (ICT) is the main enabler for the health and social care sectors, advancing user-centered care and preventing or delaying frailty conditions. This work focuses on a preliminary usability and user experience (UX) assessment regarding a self-monitoring device, smartphone, and tablet, with a 5-users sample. The user interface layout and content of smartphone and tablet have been previously simplified according to the human-computer interaction principles, to hinder the digital divide inherent to the Silver Generation. Structured and semi-structured interviews have been conducted to evaluate users' expectations, familiarity, and acceptance of ICT devices. A specific assessment protocol has been designed to evaluate the usability of devices. Preliminary results show that all participants were able to complete the test with few committed errors. However, even if a good inclination toward the use of smart technologies emerged, the need for digital mediation and individual training sessions is undisputed.

Keywords: Elderly , healthy ageing , self-monitoring , telemedicine , usability , user experience

Approximately 10% of hospitalized patients develops decubitus ulcers that quickly degenerates into chronic illness that reduces the quality of life and requires expensive clinical management. The use of an anti-decubitus active mattress, that automatically redistributes the pressure loads, reduces the occurrence of new lesions and promotes the healing of the pre-existing ones. The aim of this work is to design and develop two tools to support the design of an anti-decubitus active mattress. Almost all the systems found in literature are based on the classification of pressure maps through machine learning and are difficultly usable in the design context. This work proposes a pressure map Classifier and an Interactive Simulator of the mattress, based on a simpler logic, by integrating image processing techniques and functioning simulations. The Classifier can recognize the patient's pressure maps and classify them according to six reference sleep postures. The Interactive Simulator allows to understand the operating mechanisms of the mattress and to test the controller and the various control logics in the absence of a physical prototype.

Keywords: Active Anti-decubitus Mattress , Images Classifier , New product development , Simulation , User centred design

Automotive domain is making rapid growth in next generation cars development embedding higher levels of autonomy and intelligent assistance. Although the general advanced driver assistance system (ADAS) architectures are widely debated in the global automotive market, limited interaction between driver and these intelligent solutions sometimes make these solutions inefficient. For these reasons, the authors started an investigation about driver's feedback with respect to the intelligent assistance inputs provided by the ADAS technologies. In this context, the goal of this proposal is to show the implemented intelligent system which learns from the analysis of the car driver's eyes saccadic movements, the correlated level of attention towards the salient driving scene. With this approach, the authors were able to collect a kind of visual-feedback signal which learns the driver eye's fixing dynamic associated to the analyzed driving scene. Through ad-hoc enhanced motion magnification technique, the authors were able to amplify the mentioned saccadic dynamics to allow a downstream deep classifier to associate this physiological behavior with the corresponding level of the driver attention. The collected performances (near to 97)

Keywords: ADAS , Deep Learning , Driver eye saccadic movements , Motion Magnification

Driver posture and micro movements are main indicators of his attention and situation awareness, as well as of his capability to suddenly take control if necessary. Therefore, the real-time detection of wrong postures is essential to mitigate the risk of accidents. In this work we want to show that, by using a custom Convolutional Neural Network (CNN) for image processing, a very accurate driver posture recognition system can be realized by using a limited number of pressure sensors, grouped in a small carpet placed only on the seat of the driver, regardless of its shape. Data from the sensor carpet are converted in images reproducing the different pressure regions of the driver's body, so that the CNN can extract features and classify 8 postures with an average accuracy of 98.81% in real-time. According to the edge computing paradigm, the CNN implements an end-to-end classification by exploiting a quantization scheme for weights and binarized activations to reduce the number of required resources and allow a compact and low-power HW implementation on a small FPGA. When implemented with a Xilinx Artix 7 FPGA, the CNN consumes less than 7 mW of dynamic power at an operation frequency of 47.64 MHz. Such frequency is compatible with a sensor Output Data Rate (ODR) of 16.50 kHz, fundamental in critical applications, requiring a continuous monitoring and real-time action. Results of a 130 nm CMOS standard cells synthesis have also been reported.

Keywords: Driver safety , Neural Network , Posture recognition , Real-time image processing

With the rapid advancement of autonomous vehicles, a transformative transportation paradigm is emerging in the automotive industry, necessitating a re-evaluation of how users engage with and utilize these evolving settings. This research paper introduces an innovative interaction system tailored for shared autonomous vehicles, focusing on its development and comprehensive evaluation. The proposed system uses the car's windshield as an interactive display surface, enabling infotainment and real-time information about the surrounding environment. The integration of two gesture-based interfaces forms a central component of the system. Through a study involving twenty subjects, we analyzed and compared the user experience facilitated by these interfaces. The study outcomes demonstrated that the subjects exhibited similar behaviors and responses across both interfaces, thus validating the potential of these interaction systems for future autonomous vehicles. These findings collectively emphasize the transformative nature of the proposed system and its ability to enhance user engagement and interaction within the context of autonomous transportation.

Keywords: autonomous vehicle , gesture , haptic , head up display , human computer interaction , human machine interface , user experience

Ergonomics focuses on the analysis of the interaction between human beings and their working environment. During the riding of a motorbike, ergonomics studies the rider's posture on the motorbike. An incorrect posture can lead to physical and psychological discomfort, and can affect the perception of risk and the handling of the motorcycle. It is important for motorcyclists to adopt a good riding posture, for their health and road safety. The aim of this work is to propose a fast, cheap, and sufficiently robust method for the 3D reconstruction of the posture assumed by a motorcyclist. The stereo vision and the application of OpenPose made it possible to obtain a 3D reconstruction of the key points, and their evolution over time. The evaluation of the distances between the 3D key points, which represent the length of the various parts of the body, appears to remain sufficiently stable over time, and faithful to the real distances, as taken on the motorcyclist themself. The 3D reconstruction obtained can be applied in different fields: ergonomics, motorsport training, dynamics, and fluid dynamics analysis.

Keywords: 3D human posture , computer vision , digital twin , ergonomics , motorsport , OpenPose , posture assessment