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This paper presents the use of surface electromyographic (sEMG) signals for the actuation of soft pneumatic artificial muscles. The idea behind this paper is finding a relationship between a natural muscle and an artificial muscle, do it through an analysis of the sEMG data. We start from the characterization of a specific soft pneumatic artificial muscle and we relate the root mean square value of the sEMG signal to the contraction of the actuator itself. This work might pave the way for the development of intuitive wearable interfaces for the actuation of soft robots.

Over the past years, a wide range of dental implants has been proposed. In general, the dentists may find the best solutions according to the specific needs of the patients. A variety of factors influences the level of osseointegration and, consequently, the anchorage of the implant to the bone. The stress transfer mechanism along the bone-implant interface depends upon the surface area of the bone-implant contact. Great efforts have been devoted to the design of 3D porous lattice structures with tailored architectural features in order to reduce the implant stiffness as well as to favour bone ingrowth, thus stabilizing the device. Accordingly, the aim of the current study was to provide further insight into the design criteria for dental implants. In particular, starting from a screw implant (Implant A), different concepts of dental implants were developed: i) Implants B1–B5, with lattice shell surrounding a solid core, without thread; ii) Implant C, with lattice structure; iii) Implant D as topography optimized implant. Finite element analysis on the several models of bone-implant provided interesting information in terms of stress distributions in cortical and trabecular bone. Some differences among the implants may be ascribed to the different design criteria.

Factory acceptance test is the inspection of equipment and components at the supplier’s premises before delivery or final inspection. However, this control can represent a considerable cost for the customer, especially when the manufacturer’s company is geographically far from the customer one and inspections must be frequent. In this paper, the authors present a framework to support the factory acceptance test based on augmented reality (AR) techniques and model-based definition aimed at dimensional checks that does not require the physical presence of the customer at the supplier's premises. The supplier must be previously equipped with an automatic measuring machine. Once the component under inspection is placed inside the machine, this reads the type and the position of the features to be measured along with the related specification limits directly from the annotated 3D model of the component. The results are automatically transmitted to the customer’s site. Through a tablet, the supplier, guided by the customer, reads the results of the measures directly on the measured object through augmented or mixed reality techniques. Any out-of-specification dimension can be remeasured in real time with the customer’s remote assistance using traditional measurement techniques. The proposed architecture, at an advanced stage of experimentation, is discussed with reference to an industrial case study proposed and using an entry level commercial 3D scanner.

Made available in DSpace on 2021-06-25T11:13:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-01 The aim of the present study was to investigate the effect of shrinking and no shrinking dental filling materials combination in posterior restorations under the combined effects of polymerization shrinkage and occlusal load by means of 3D Finite Elements Analysis. Six computer-generated and restored class I or class II cavities models of a lower molar were designed in the CAD software and evaluated according to the cavity and restorative procedure. Different shrinking and no shrinking adhesive materials combination with diverse Young’s modulus were considered. A food bolus was modeled on the occlusal surface replicating the chewing load using static linear analyses Polymerization shrinkage was simulated for the shrinking different restorative materials. The maximum principal stress was selected as analysis criteria. All models exhibited higher stresses along the dentine restoration interfaces with different magnitude and a similar stress trend along enamel restoration interface. Stress values up to 22 MPa and 19 MPa were recorded in the enamel and restoration, respectively. The use of elastic not shrinking material layer in combination with bulk fill composite reduced the stress magnitude in dentine and enamel to replace dental tissues. Class I and class II posterior cavities adhesively restored with shrinking filling material’s combination showed the most unfavorable stress concentrations and the multilayer technique is a promising restorative alternative in posterior adhesive restorations when deep dentin and enamel volumes are missing. School of Dentistry University of Naples Federico II, via S. Pansini 5 Department of Dental Materials and Prosthodontics Institute of Science and Technology São Paulo State University-UNESP Fraunhofer JL IDEAS Department of Industrial Engineering University of Naples Federico II Endodontic Clinical Section School of Dentistry Department of Biomedical and Neuromotor Sciences University of Bologna-Alma Mater Studiorum School of Dentistry University of Taubaté–UNITAU, Taubaté Department of Dental Materials and Prosthodontics Institute of Science and Technology São Paulo State University-UNESP

Applications as robotic harvesting or pick and place in the agrifood domain require robotic grippers able to gently manipulate delicate products, while guaranteeing high gripping power and adhesion forces on smooth surfaces. Existing soft grippers are mainly based on pneumatic bending actuators which can guarantee a gentle manipulation, but they suffer from low gripping power and possibility of slip of the manipulated object. This paper describes a novel design concept of soft robotic pneumatic gripper with embedded suckers. The concept consists of four soft fingers, each one comprising an elastomeric structure with two separate air paths, one for pressurizing the finger for generating bending motion, one for vacuum–based adhesion to the object’s surface via suction pads distributed along the surface of the finger. In this work we highlight the concept design of the mechanical system and the pneumatic control unit.

Titanium alloys (e.g., Ti6Al4V) have been widely considered for the design of biomedical implants. To avoid stress shielding effects, bone atrophy and implant loosening bone, 3D porous devices with controlled geometry and architecture should represent a promising solution. Several cellular structures were already investigated to obtain a wide range of mechanical properties. Many studies focused on the mechanical performance of diamond and body-centered-cubic. Different kinds of porous and semi-porous femoral stems were also proposed and analyzed. Accordingly, the aim of the current research was to provide further insight into the design of solid-lattice hybrid structures through a two-step process involving the classical and lattice topology optimization. A cementless femoral stem was considered as a case study. The solid isotropic material with penalization (SIMP) was used at varying values of the penalty factor and the effect of the geometrical features of each beam forming the lattice structure was also determined. Differences were found in terms of functional and structural performances according to the selected strategy for the design of the solid-lattice hybrid structures, as a consequence of the material distribution/layout and geometrical features.

Nowadays, the commercial translation of additive manufacturing technologies for scaffolds fabrication is still a challenge. The production methodology of 3D scaffolds for tissue regeneration is a complex and discontinuous process involving several stages, from the isolation of the stem cells to the dynamic cell culture in vitro. Even though in this scenario industries are increasingly implementing automated robotic systems, current technologies are not enough to realize a large industrial scale scaffold fabrication. Accordingly, a relevant improvement could raise from the implementation of a modern collaborative workplace in an existing production line, combining strength endurance and accuracy of cobots, with intelligence, flexibility, and adaptability of the human being. Such a solution overcomes limits related to the low level of process control, low productivity, and risk of contaminations. Therefore, the current work proposes a systematic approach to the design of a collaborative workplace for biomanufacturing of 3D scaffolds. Starting from an overview of basic concepts on scaffolds for tissue engineering and additive manufacturing, as well as from an analysis of automation solutions in cell culture applications, a design methodology section is reported. The paper provides a further insight into the potentials to upscale the scaffolds manufacturing process, taking advantage of the huge possibilities given from the Human-Robot Collaboration and gives evidence of critical features for workplace definition.

Additive manufacturing (AM) allows the development of novel and customized products with tailored properties. However, the application of extrusion-based AM techniques (i.e., fused deposition modeling - FDM) in the design of functional parts is often limited because of the poor mechanical performance as a consequence of the nature of the process to build the object in a layer-by-layer fashion. In the current study, the impact resistance of the 3D printed polyethylene terephthalate glycol-modified (PETG) and high impact polystyrene (HIPS) was evaluated as a function of three printing parameters (i.e., printing temperature, layer height and line width). Izod-type test specimens were fabricated and analyzed according to the ASTM D256. The contribution of each factor was properly analyzed. The results also indicated that the printing temperature was the most significant parameter for the impact resistance of 3D printed PETG and HIPS. The obtained findings may be considered as valid only within the limit of parameters and ranges investigated in the current study.

In this paper, we present a biomechanical analysis of the upper body, which includes upper-limb, neck and trunk, during the execution of overhead industrial tasks. The analysis is based on multiple performance metrics obtained from a biomechanical analysis of the worker during the execution of a specific task, i.e. an overhead drilling task, performed at different working heights. The analysis enables a full description of human movement and internal load state during the execution of the task, thought the evaluation of joint angles, joint torques and muscle activations. A digital human model is used to simulate and replicate the worker’s task in a virtual environment. The experiments were conduced in laboratory setting, where four subjects, with different anthropometric characteristics, have performed 48 drilling tasks in two different working heights defined as low configuration and middle configuration. The results of analysis have impact on providing the best configuration of the worker within the industrial workplace and/or providing guidelines for developing assistance devices which can reduce the physical overloading acting on the worker’s body.

In this work we derive the requirements of a soft upper-limb exoskeletons starting from the biomechanical analysis of human workers while performing three different industrial overhead tasks in laboratory settings. The results of the work allow to define the degrees of freedom which need to be supported to reduce the biomechanical overloads, as well the dimensional characteristics, in terms of required lengths and forces, of the soft actuators of the wearable robot.

The innovation driven Industry 5.0, in agreement with Industry 4.0, leads to consider human in a prominence position as the center of manufacturing field. This pushes towards the hybridization of manufacturing plants promoting a fully collaboration between human and robot. Furthermore, the new paradigm of "human centred design" and "anthropocentric design" allows enabling a synergistic combination of human and robot skills. However, properly collaborative workplaces are currently very few. Industry is still not confident, and systems integrators hesitate to venture into Human-Robot Collaboration (HRC). Despite the effort in collaborative robotics, a general solution to overcome the current limitations in designing of collaborative workplaces still misses. In the current work, a Knowledge-Based Approach (KBA) is adopted to face collaborative workplace designing problem. The framework resulting from the KBA allows developing a modelling paradigm that enable to define a streamlined approach for the layout designing of a collaborative workplace. Finally, a what-if analysis and a ANOVA analysis are performed to generate and evaluate a set of scenarios related to a collaborative workplace for quality inspection of welded parts. Facing the high complexity and multidisciplinary of HRC can be conveyed to develop a general design approach aimed at overcoming the difficulties that limit the spread of HRC in the manufacturing field.

Made available in DSpace on 2022-05-01T10:51:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-11-01 Evidence regarding the effect of the onlay preparation design for different CAD/CAM restorative materials considering the preservation of cusps is lacking. Molars were 3D-modeled in four preparation designs for onlay restoration: Traditional design with functional cusp coverage (TFC), non-retentive design with functional cusp coverage (NFC), traditional design with non-functional cusp coverage (TNFC) and non-retentive design with non-functional cusp coverage (NNFC). The restorations were simulated with two CAD/CAM restorative materials: LD—lithium disilicate (IPS e.max CAD) and RC—resin composite (GrandioBloc). A 100 N axial load was applied to the occlusal surface, simulating the centric contact point. Von Mises (VM) and maximum principal (Pmax) stress were evaluated for restorations, cement layer and dental substrate. The non-retentive preparation design reduced the stress concentration in the tooth structure in comparison to the conventional retentive design. For LD onlays, the stress distribution on the restoration intaglio surface showed that the preparation design, as well as the prepared cusp, influenced the stress magnitude. The non-retentive preparation design provided better load distribution in both restorative materials and more advantageous for molar structure. The resin composite restoration on thenon-functional cusp is recommended when the functional cusp is preserved in order to associate conservative dentistry and low-stress magnitude. School of Dentistry Universidad Espíritu Santo Institute of Science and Technology São Paulo State University (Unesp) São José dos Campos Department of Dental Materials Academic Centre for Dentistry Amsterdam (ACTA) University of Amsterdam and Vrije Universiteit Amsterdam Department of Dentistry Center for Biological and Health Sciences Western Paraná State University (Unioeste) Fraunhofer JL IDEAS Department of Industrial Engineering University of Naples Federico II School of Dentistry University of Naples Federico II Institute of Science and Technology São Paulo State University (Unesp) São José dos Campos

ObjectiveThe aim of this study was to evaluate the influence of three different dental implant neck geometries, under a combined compressive/shear load using finite element analysis (FEA). The implant neck was positioned in D2 quality bone at the crestal level or 2 mm below.MethodsOne dental implant (4.2 × 9 mm) was digitized by reverse engineering techniques using micro CT and imported into Computer Aided Design (CAD) software. Non-uniform rational B-spline surfaces were reconstructed, generating a 3D volumetric model similar to the digitized implant. Three different models were generated with different implant neck configurations, namely 0°, 10° and 20°. D2 quality bone, composed of cortical and trabecular structure, was modeled using data from CT scans. The implants were included in the bone model using a Boolean operation. Two different fixture insertion depths were simulated for each implant: 2 mm below the crestal bone and exactly at the level of the crestal bone. The obtained models were imported to FEA software in STEP format. Von Mises equivalent strains were analyzed for the peri-implant D2 bone type, considering the magnitude and volume of the affected surrounding cortical and trabecular bone. The highest strain values in both cortical and trabecular tissue at the peri-implant bone interface were extracted and compared.ResultsAll implant models were able to distribute the load at the bone-implant contact (BIC) with a similar strain pattern between the models. At the cervical region, however, differences were observed: the models with 10° and 20° implant neck configurations (Model B and C), showed a lower strain magnitude when compared to the straight neck (Model A). These values were significantly lower when the implants were situated at crestal bone levels. In the apical area, no differences in strain values were observed.SignificanceThe implant neck configuration influenced the strain distribution and magnitude in the cortical bone and cancellous bone tissues. To reduce the strain values and improve the load dissipation in the bone tissue, implants with 10° and 20 neck configuration should be preferred instead of straight implant platforms.

In this paper, we propose a user-centered approach for the design of ergonomic workplaces. The method is based on the evaluation of subjective opinions and objective measures from the worker, while performing the industrial tasks. The ergonomic design of industrial workplaces will have impact in reducing the musculoskeletal disorders of workers.

Aircraft seat is rated as the most unsatisfying aspect of flying; under-standing the main factors impacting on passenger’s evaluations can provide a concrete opportunity for airlines to improve seat comfort and thus enhance pas-senger satisfaction and loyalty. Although there is a great deal of interest, the re-search on effective assessment strategies for subjective comfort is still underde-veloped. In this study a model-based approach for the analysis of subjective comfort data is suggested. The model adopted can be interpreted as a parametric version of the psychological process generating comfort ratings. The proposed approach is exploited through a case study concerning comfort assessment of aircraft seats designed for regional flights.

BACKGROUND: Aircraft seating comfort has a significant impact on passenger on-board experience. Its assessment requires the adoption of well-designed strategies for data collection as well as appropriate data analysis methods in order to obtain accurate and reliable results. OBJECTIVES: This paper focuses on the assessment of aircraft seating comfort based on subjective comfort responses collected during laboratory experiments and taking into account seat features and passenger characteristics. METHODS: The subjective comfort evaluations have been analyzed using a model-based approach to investigate the relationship between overall seating comfort and specific seat/user characteristics. RESULTS: The results show that the overall seating comfort perception is significantly influenced by the thickness of the seat pan, the backrest position (upright or reclined), the age of the passenger and the passenger perception of being comfortably supported at the lumbar region. CONCLUSIONS: The adopted model-based approach allows the analysis of subjective seating comfort data taking into account their ordinal nature as well as the dependency between evaluations provided by the same subject.

Race walking is a discipline in which the best chronometric performance is constrained by infringements. Currently, the judgment and training of race walkers is entrusted to subjective observations made by judges. In this paper, with the objective of supporting coaching and judging, we present a wearable inertial sensor system (IART) for the evaluation of performances and infringements in race walking. The system is composed of an inertial sensor positioned close to the center of mass of the subject and a management unit designed for coaches and judges. IART allows: (i) a step sequence classification according to the competition rules; (ii) a customized assessment of elite race walkers based on key performance and infringement indices. The system is experimentally validated in field conditions by nine world-class Olympic race walkers. The results show that IART improves the current evaluation of step sequences and offers a meaningful support for the overall evaluation of the technical gesture.

Design process is usually based on past experiences and best practises which compose the company know-how. The challenge is to identify common patterns in the design solutions generated for different design problems. The present paper focuses on the identification of product patterns by using a graph-based approach. It deals with the designing of automotive gearboxes and with the development of an approach and a software tool aimed to support preliminary design and CAD modelling activities in gearbox designing. The approach is applied to two different architectures of manual transverse gearboxes characterized by two and three shafts. It aims at the identification of common design features through the detection of the directed graphs matching. A Matlab software tool for gearbox preliminary design is implemented according to the detected common features. The proposed approach and the developed software tool provide an effective way to keep and re-use company know-how, especially in the context of large automotive companies.

Most occupational safety regulations and international standards recognize the importance of keeping a corporate document that set all the safety procedures prescribed for a certain workplace. However, experience show that, to be truly effective, any piece of information must be kept updated and correctly delivered to the right recipient. From this point of view, the possibility, given by modern technology, to receive, process and send information in real time using common smartphones is a great opportunity. The authors developed a solution for mobile devices, which is based on augmented reality technologies and indoor positioning algorithms, aimed at speeding up and simplifying the information flow among safety managers, workers and casual users about safety-related content. Safety managers can use it as a support tool for the preparation of the risk assessment documentation, on the workers’ side, the same application acts as an informational tool providing safety-related content when and where needed through augmented reality technologies. Preliminary results from in situ testing show that augmented reality may be a powerful tool to improve the occupational safety.

Nowadays, technology in sport plays an important role to help training and judgement processes. This study proposes the use of a wearable inertial system to derive novel biomechanical indices for the assessment of performance and infringements in race-walking. These indices are built from five inertial-based parameters: loss of ground contact time, loss of ground contact step classification, step length ratio, step cadence and smoothness. The biomechanical indices are customized for elite race-walkers, and represented on a radar chart for an intuitive analysis of performance and infringements. From the radar chart, a synthetic index regarding the athlete’s overall gesture is derived. The validation of the biomechanical indices is carried out in field tests, involving nine elite race-walkers wearing an inertial sensor located at the end of the column vertebra (L5–S1). A statistical analysis is used to determinate the quality and reliability of the proposed indices and of their representation. The results show that these biomechanical indices can be implemented on a wearable inertial system for assistance in training and judgement in race-walking.

This research discusses the use of a systematic design method, the Iterative and Participative Axiomatic Design Process (IPADeP), for the early conceptual design stage of large-scale engineering systems. The involvement of multiple and competing requirements has imposed high challenges for achieving an affordable design of complex systems in a reasonable lead time. Systems Engineering (SE) focuses on how to design and manage complex systems over their life cycles. Both must begin by discovering the real problems that need to be resolved and identifying from the early stage of the design the main stakeholder requirements and customer needs. The Axiomatic Design (AD) methodology is widely recognized in the literature to efficiently support the design of complex systems from the early conceptual stage. IPADeP provides a systematic methodology for applying AD theory in the conceptual design of large-scale engineering systems, aiming to minimize the risks related to the uncertainty and incompleteness of requirements and to improve the collaboration of multi-disciplinary design teams. IPADeP has been adopted as design methodology in the pre-conceptual design stage of a subsystem of the DEMOnstration fusion power plant (DEMO): the divertor cassette body-to-vacuum vessel locking system. In this paper improvements in IPADeP are presented and its validity is discussed by presenting the application to the divertor system design.

A fast and objective evaluation of kinematic characteristics of an elite athlete's gesture is necessary for refining her/his performance. When the athlete has a reduced capacity and/or reliability of expression, as in the case of subjects with intellectual impairment, objective performance analyses are even more important. In this work, we present a preliminary study regarding performance analysis on sprint tests performed by elite athletes with intellectual impairment, wearing an inertial sensor at the bottom end of their vertebral column. In particular, we compare three different inertial-based algorithms for automatic detection of temporal events, in steady-state velocity phase, with respect to the benchmark values obtained through video analysis.

People with intellectual impairment show low performances in motor control, especially in complex movements. Performance analysis methods, based on wearable inertial sensor, are often used in typical developed swimmers but have never been used in swimmers with intellectual impairment, for whom the use of quantitative systems would be even more important. This paper presents a case study conducted on freestyle swimmers from the functional evaluation project of the Italian Sport Federation for athletes with Intellectual Impairment (FISDIR). The tests were conducted by five Italian elite swimmers with intellectual impairment using a structured experimental protocol which foresees an inertial sensor located on the wrist. Key freestyle temporal and kinematic parameters were assessed. A high-speed camera was used as a benchmark to validate the inertial-based parameters. The preliminary results indicate that the proposed inertial-based approach correlates over 90% with the performance indices obtained with the camera-based approach, and therefore it could represent a useful tool for monitoring and improving the training.

In this paper we present novel biomechanical indices for site-specific assessment of injury risk in cycling. The indices are built from a multifactorial analysis based on the kinematics and kinetics of the cyclist from the biomechanical side, and muscle excitations and muscle synergies from the neurophysiological side. The indices are specifics for three body regions (back, knee, ankle) which are strongly affected by overuse injuries in cycling. We use these indices for injury risks analysis of a recreational cyclist, who offered to participate in the experiments. The preliminary results are promising towards the use of such indices for planning and/or evaluating training schedule with the final goal of reducing non-traumatic injuries in cycling.

In the current research, an optimization design strategy for additive manufacturing processes based on extrusion/injection methods was extended to the fabrication of poly(e-caprolactone) (PCL)/iron oxide (Fe3O4) scaffolds for tissue engineering. The attention was focused on four parameters: process temperature (PT), deposition velocity (DV), screw rotation velocity (SRV), slice thickness (ST). Specifically, PCL/Fe3O4 scaffolds were manufactured varying iteratively one parameter, while maintaining constant the other three parameters. A further insight into the influence of process parameters on the morphological features and mechanical properties of PCL/Fe3O4 scaffolds was provided.

Excessive values of force on L5/S1 joint can cause work-related musculoskeletal disorders, such as low back pain. Currently, the reference solution for estimating such variables is the combination of optoelectronic system and force platform, used for calculating the bottom up inverse dynamics in laboratory settings. Here we propose and validate a novel, completely wearable solution, composed by twelve inertial measurement units and pressure insole sensors. We validate the wearable solution with respect to the output of the reference solution, with data collected simultaneously on a subject performing lifting and releasing tasks with two different loads. The results are encouraging towards the use of the wearable methodology, considering the great impact of such a solution in a real manufacturing scenario.

This paper deals with collaborative robotics by highlighting the main issues linked to the interaction between humans and robots. A critical study of the standards in force on human–robot interaction and the current principles on workplace design for human–robot collaboration (HRC) are presented. The paper focuses on an anthropocentric paradigm in which the human becomes the core of the workplace in combination with the robot, and it presents a basis for designing workplaces through two key concepts: (i) the introduction of human and robot spaces as elementary spaces and (ii) the dynamic variations of the elementary spaces in shape, size and position. According to this paradigm, the limitations of a safety-based approach, introduced by the standards, are overcome by positioning the human and the robot inside the workplace and managing their interaction through the elementary spaces. The introduced concepts, in combination with the safety prescriptions, have been organised by means of a multi-level graph for driving the HRC design phase. The collaborative workplace is separated into sublevels. The main elements of a collaborative workplace are identified and their relationships presented by means of digraphs.

Objectives To investigate the influence of different resin composite and glass ionomer cement material combinations in a “bi-layer” versus a “single-layer” adhesive technique for class I cavity restorations in molars using numerical finite element analysis (FEA). Materials and Methods Three virtual restored lower molar models with class I cavities 4 mm deep were created from a sound molar CAD model. A combination of an adhesive and flowable composite with bulk fill composite (model A), of a glass ionomer cement with bulk fill composite (model B) and of an adhesive with bulk fill composite (model C), were considered. Starting from CAD models, 3D-finite element (FE) models were created and analyzed. Solid food was modeled on the occlusal surface and slide-type contact elements were used between tooth surface and food. Polymerization shrinkage was simulated for the composite materials. Physiological masticatory loads were applied to these systems combined with shrinkage. Static linear analyses were carried out. The maximum normal stress criterion was adopted as a measure of potential damage. Results All models exhibited high stresses principally located along the tooth tissues–restoration interfaces. All models showed a similar stress trend along enamel–restoration interface, where stresses up to 22 MPa and 19 MPa was recorded in the enamel and restoration, respectively. A and C models showed a similar stress trend along the dentin-restoration interface with a lower stress level in model A, where stresses up to 11.5 MPa and 7.5 MPa were recorded in the dentin and restoration, respectively, whereas stresses of 17 MPa and 9 MPa were detected for model C. In contrast to A and C models, the model B showed a reduced stress level in dentin, in the lower restoration layer and no stress on the cavity floor. Significance FE analysis supported the positive effect of a “bi-layer” restorative technique in a 4 mm deep class I cavities in lower molars versus “single-layer” bulk fill composite technique.

Light activated composites are the most popular choice in the field of dental restoration. They generally show internal stress even after a prolonged time period. The knowledge of mechanical properties and residual stress should provide interesting information on the clinical performance of such materials. Accordingly, in the current research experimental analyses were carried out to assess the effect of the curing process on the properties of one of the most commonly employed light activated dental composites (Gradia Direct-GC Corporation, Japan). At 10 min, 1 h and 24 h after light curing, the bending modulus (4.7-6.2 GPa) as well as the punching performance (peak load of 12.1-17.5 N) were evaluated for the micro-hybrid composite. Scanning electron microscopy also allowed to analyze the fracture surface. Residual stresses ranging from 0.67 ± 0.15 MPa to 1.12 ± 0.17 MPa were measured by means of the thin-ring-slitting approach reported in the literature, according to measurement time and cutting time.

In a complex case of speech disorder, the communication is entrusted to systems equipped with a speech synthesizer. When the user has a motor disability, in addition, hardware and software interfaces are personalized to make technology more accessible. Interaction design methods can be applied to develop improved assistive systems and, particularly, for Augmentative and Alternative Communication (AAC). Interaction design methods and usability evaluation could have a positive impact in reducing product barriers and improving performances as the effort state associated to its use can be reduced. Minimizing cognitive and physical efforts through the development of new solutions and interface optimization can be challenging. A usability test and an interface optimization of a personalized AAC system developed for a student of the University of Naples Federico II with complex communication needs due to a traumatic injury and motor impairment are discussed to fix usability issues, highlight critical areas and design new prototypes.

The key findings about the use of a MOOC (Massive Open Online Course) at University of Naples Federico II are shown. In particular, the Engineering Drawing course for Industrial Engineering students was the pilot to evaluate the benefits of new Web-Based Platforms and Environments in higher education. The combination of In-Class and On-Line lessons is defined “Blended Course” and can be attended by students both in traditional classrooms and On-Line. It was provided during the last four academic years allowing the use of new tools (e.g., multimedia contents, interactive files). Thanks to about 7000 students involved in this project, several data were gathered for statistics and analysis purposes. Therefore, the access to the MOOC was monitored and the correlation with the homework was examined. At the end of the course, the level of satisfaction of the students about the interaction with the new platform was evaluated. The analysis of the results provided useful hints for the updating of the course in order to improve skills and interactive experience.

In this work we present a study for the experimental reconstruction of the human shoulder torque in the sagittal plane, since this is usually overloaded in industrial overhead tasks. To this end, we measure the three-dimensional motion of the human upper limb while performing selected movements using an optical motion capture system. Then, using a skeleton model implemented in one of the most common software for industrial ergonomic assessment, we reconstruct the shoulder angle and torque in the sagittal plane. A possible exploitation of this reconstruction strategy is presented for active compensation of this torque. The implementation of this simple strategy in a custom developed assistive device could augment human workers in performing repetitive jobs. © 2019 IEEE.

Products aimed at individuals with disabiliy could not match user requirements under conditions imposed by the user. Also, frequent modifications and adaptation are required to increase the match between user requirements and prototypes. The importance to test different solutions and gain a knowledge base is an important aspect as the time in trials and experimentation is still a limit of personalized devices. An experimentation is conducted to test a solution of hardware interface for an Augmentative and Alternative Communication System which implements visual feedbacks and visual tutorial in training phase. In this study, visual feedbacks demonstrate an improvement of performances due to three main effects: reducing training time through an interactive tutorial, improving automatic behaviour and limiting cognitive load. The prototypes are realized using open-source electronic boards and Additive Manufacturing to realize the housing. A usability test is performed to calculate metrics and benchmark solutions with and without visual aids. Measures of Lostness and Keystroke Level Model estimates the effectiveness of software interface and interaction of users with hardware and software interfaces.Also, this study can lead to the definition of an adaptive switch that modify its status in order to eliminate redundant operations and ineffective actions.Visual feedback has proven some advantages in training user and Additive Manufacturing enabled the study and lead the way for devices that are adaptive on software interface and control and personalized in the hardware interface.

The musculoskeletal disorders represent one of the most common problems in industrial environment; they impact the health of workers and employees. In this work we present a preliminary study towards the use of biomechanical models for improving classic methods for ergonomic assessment in industry. To this end, we use OpenSim, a software for biomechanical simulation and analysis. With OpenSim, we reconstruct the human motion corresponding to the execution of industrial tasks, performed in laboratory settings. In particular, we compute the evolution over time of the joint angles that, according to a classic observation method for ergonomic assessment, are needed to evaluate the risks associated to the musculoskeletal disorders for the upper limb. © 2019 IEEE.

The present paper deals with collaborative robotics and proposes to enable collaborative workstations by means of the critical study of the in-force standards on Human Robot Cooperation. The paper introduces the anthropocentric paradigm and presents a new basis for designing workstation composed by two key concepts: (i) human and robot spaces are elementary spaces able to generate all other spaces; (ii) dynamic variations of the elementary spaces in terms of shape, size and position occur. Moreover, dynamic positions of human and robot spaces enable collaborative operations in case of mobile robots.

In the scientific literature, the debate about how define and evaluate seat comfort is still open, but three points are not in question [1]: 1. comfort is a construct of a subjective nature; 2. comfort is affected by factors of various nature (physical, physiological, psychological); 3.comfort is a reaction to the environment. The subjective nature of the comfort experience is universally recognized; any comfort analysis cannot disregard subjective methods (‘directly asking people about how comfortable they are’), which can be regarded as the most direct way to detect subjective feelings of comfort and/or discomfort. This paper focuses on the assessment of aircraft seating comfort based on subjective comfort responses collected during laboratory experiments. During each experimental session, participants were asked to express their overall seat comfort perception and to evaluate specific seat design features. Comfort responses were analyzed with the aim to relate the perceived overall seat comfort to some design features, as well as to the user anthropometrical characteristics and feelings. The adopted statistical modeling approach is based on generalized linear mixed models. Differently from the traditional strategies used for the analysis of subjective sitting comfort data (e.g. correlation analysis, non-parametric hypothesis tests), the model-based approach allows to investigate and quantify the relationship between overall seat comfort and specific seat/user characteristics. The results show that the overall comfort perception is significantly influenced by age, lumbar support, height of seat pan and reclining.

This paper focuses on the comparative assessment of comfort and discomfort (hereafter, (dis-)comfort) for air- craft seating. Subjective and objective data of seating (dis-)comfort were collected during an experiment in- volving 20 volunteers who tested 3 aircraft double-seats in upright and reclined position. In order to minimize experimental uncertainty due to well-known noise factors (i.e. patterns of discomfort during the work week and during the work day, order of evaluation, inter-individual differences), experimental trials were performed according to a crossover design. Statistical data analysis aimed mainly at investigating (dis-)comfort differences across seat conditions; gender-based differences in perceived discomfort on different body parts; effect of sitting duration on perceived discomfort on different body parts. The experimental results show that differences across seat conditions impacted differently on perceived discomfort depending on gender, body parts and sitting duration. No significant differences in perceived discomfort across gender were evident for the lightweight seat in both upright and reclined positions. On the contrary, for both baseline configurations, perceived discomfort at head and neck areas was higher for males than for females. For all seat conditions, participants experienced a significant worsening of perceived comfort over time at shoulders, back, sacrum and thighs and, in addition, at upper body area (i.e. neck, arm and forearm) and knees only for seats in reclined position.

This paper presents an interactive design method aimed at improving workplace health and safety. Human performances and anthropometric variability are carefully considered to make the workplace “robust” from a safety point of view. This topic is of increasing interest to industries that plan to make safer workplaces without renouncing to their productivity targets. A challenging issue concerns the evaluation of the effects of sources of anthropometric variability in the process by using just a small sample of real or digital humans. The adoption of a discretization technique helps to solve this problem and saving time and resources. Through real industrial case studies, the authors investigate the main ergonomic and safety issues faced during the development of both manual and human–robot hybrid workcells.

We propose to use an industrial redundant manipulator (KUKA LBR iiwa robot) as a haptic device to provide high force feedback for an orthopedic surgeon while performing the reaming of the acetabula in a virtual environment. Real experiments have been performed to validate the virtual reality training framework. The results show that the system resulted to be intuitive and reliable from the users experience. © 2019 IEEE.

The objective of the work is to describe the design and the realization of a virtual simulator of a metropolitan railway cockpit, aimed at improving the perception of safety by means of tests made by users in Virtual Reality, analysed through statistical methodologies. The user lives the experience of a driver in an immersive and interactive Augmented Reality session, interacting with the train dashboard and all its control and signalling devices. In particular, the user is proposed to test different dashboards, different configurations of the controls and different signalling and safety devices in order to compare different concept and select the optimum in terms of perception of dangerous situation, reaction to an event and cognitive response in different situations of the rail vehicle driving. The simulator consists of a simulacrum integrating different technologies, physically composed of a dashboard of the cockpit of a metropolitan train and a real seat. The geometry of the dashboard has been acquired through Reverse Engineering techniques from a real train dashboard. The user’s immersion in the virtual environment during the simulation is guaranteed by the scene displayed on the Augmented Reality device, while, simultaneously, the stereoscopic projection on a screen above the dashboard makes available the experience even to users not directly involved, seeing the scene from the driver’s point of view. The immersive Augmented Reality is realized through a Head-Mounted Display (HMD) by which the user, protagonist of the driving experience, sees the configuration of the virtual control devices (CAD geometries) overlapped with the physical dashboard in order to naturally interact into the immersive environment. The interaction between user and simulator happens through the NUI (Natural User Interfaces) based on markerless tracking of parts of the user’s body.