Abstract: Background: Pumping in Laser-class sailing is a dynamic propulsion technique used in marginal wind conditions and characterized by repetitive, coordinated oscillations of the sailor–sail system. Despite its practical relevance, its biomechanical and ergonomic demands remain insufficiently characterized. Methods: A mixed-methods framework was applied combining questionnaire data, kinematic analysis, ergonomic assessment, and musculoskeletal modelling. Thirty-six competitive Laser sailors completed a Borg CR-10-based questionnaire on perceived discomfort/fatigue across body regions at predefined time points (during pumping, immediately after training, and the following day). A controlled land-based multi-angle video acquisition was used to reconstruct a standardized pumping posture and parameterize a digital human model in DELMIA® for postural/kinematic analysis. Ergonomic risk was assessed using REBA, and muscle activity was estimated using the AnyBody® Modeling System (simulation-derived normalized muscle activity across 129 muscles). Results: the simulation identified high neuromuscular demand in the trunk and shoulder complex, with several deep trunk stabilizers and the left latissimus dorsi reaching 100% modeled normalized muscle activity. Marked lateral asymmetry was observed, with right-sided trunk dominance and left-sided shoulder dominance. Kinematic analysis showed substantial joint excursions, with large lumbar motion amplitudes, while REBA yielded a score of 11 (Very-High Risk). Questionnaire data indicated a high prevalence of pumping-related musculoskeletal discomfort (72.2%), most frequently involving the lower back, shoulders, and knees. A dissociation was observed between modeled muscle activity and perceived fatigue, with the lower limbs rated as most fatigued despite lower modeled activation than the trunk. Conclusions: Findings identify the deep trunk stabilizers, latissimus dorsi, and lower extremities as key regions involved in pumping, with marked lateral asymmetry and high ergonomic risk. They support targeted training, injury-prevention, and ergonomic strategies to improve performance and reduce injury risk in competitive sailing.

Keywords: discomfort | laser sailing | muscle activation | musculoskeletal simulation | pumping maneuver | REBA ergonomic assessment

Abstract: This investigation examined the perceptual-motor distortions induced by mixed reality head-mounted displays during spatial navigation tasks. Employing a two-phase experimental paradigm, we initially quantified kinematic differences between helmet and non-helmet conditions, subsequently assessing sensorimotor adaptation through repeated bidirectional trajectory navigation. Fifty participants executed standardized trajectories while three-dimensional movement kinematics were recorded via spatial tracking. Statistical analyses revealed significant alterations in movement parameters during helmet use, characterized by increased trajectory tortuosity and elevated oscillation frequency. Qualitative assessment of movement patterns demonstrated systematic lateral deviations perpendicular to the intended vector, suggesting distortion of depth perception and spatial mapping processes. Longitudinal analysis of adaptation metrics indicated a 42.72% reduction in oscillation frequency between early and late trials, though this effect did not reach conventional statistical significance. These findings contribute to the theoretical understanding of technologically induced perturbations to spatial cognition and motor control, while establishing trajectory tortuosity as a sensitive metric for quantifying mixed reality performance decrements. The documented adaptation phenomena have significant implications for training protocols in professional applications of mixed reality technology.

Keywords: Head-Mounted Display | Mixed Reality | Spatial Navigation | Tortuosity

Abstract: The global demographic shift toward an aging population presents significant implications for automotive design and safety. This research addresses a critical gap in the literature by conducting a comprehensive ergonomic assessment of elderly drivers during two essential driving tasks: reverse gear maneuvers and seat belt engagement. Through a methodologically rigorous approach combining quantitative discomfort evaluations and postural analyses, this study examined a sample of 20 elderly people, a B-segment car and a strategically positioned recording equipment. The investigation revealed statistically significant patterns of discomfort concentration in the upper body regions, particularly the shoulders and cervical area, with Rapid Upper Limb Assessment (RULA) scores indicating substantial musculoskeletal risk factors. The findings demonstrate that conventional automotive configurations impose asymmetric postural stresses that are particularly problematic for elderly users due to age-related physiological changes. This research contributes to the theoretical understanding of aging-specific ergonomic requirements and provides empirical evidence supporting the necessity for adaptive design modifications to enhance safety, comfort, and continued mobility independence among the elderly population.

Keywords: Elderly population | Ergonomics | Postural Discomfort

Abstract: Brain arteriovenous malformations (AVMs) are complex cerebrovascular lesions characterized by abnormal direct connections between arteries and veins, resulting in altered hemodynamics and an increased risk of rupture. Following PRISMA, a comprehensive review on CFD-based modelling in brain AVMs was conducted across major scientific databases, including Pub-Med/MEDLINE, Scopus, Web of Science, Google Scholar, EBSCO Academic Search and IEEE Xplore, evaluating its role in hemodynamic analysis and pre-procedural planning. Twenty-three studies met the inclusion criteria and were analyzed through both qualitative synthesis and bibliometric approaches. Bibliometric analysis revealed a growing research interest in image-based modelling, 4D flow imaging and virtual embolization after 2021. Despite recent advances in study of hemodynamics simulations, the application of computational fluid dynamics (CFD) to brain AVMs remains challenging due to their complex vascular architecture and highly heterogeneous flow patterns. Nevertheless, CFD remains an important imaging modality for characterizing the lesion and guiding pre-interventional decision making.

Keywords: 3D reconstruction | arteriovenous malformations (AVMs) | computational fluid dynamics (CFD) | neuroimage modelling | treatment planning

Abstract: Human digital twins (HDTs) are patient-specific computational models that combine medical imaging, physiological measurements and predictive algorithms. They are moving from an exciting concept to a realistic clinical opportunity. The key question is no longer whether HDTs can be built. The key question is which methods are mature enough to support clinical decisions and what is still missing for routine use. This systematic review maps the methodological landscape of HDTs and highlights practical bottlenecks that limit clinical translation. A PRISMA 2020 guided search of PubMed, Scopus, IEEE Xplore, and the Cochrane Library, covering publications from 2016 to 2026, identified 151 eligible studies. Bibliometric mapping and thematic synthesis were used to characterize research clusters, computational paradigms, and collaboration patterns. Three dominant application streams were identified: cardiovascular HDTs for hemodynamic simulation and procedural planning, musculoskeletal HDTs for biomechanics-driven orthopedic innovation, and neurological HDTs integrating neuroimaging with computational neuroscience. Across domains, the strongest technical trend is the rise in hybrid pipelines that combine physics-based simulation, including finite element and computational fluid dynamics models, with machine learning for segmentation, parameter identification, reduced-order modeling, and faster inference. However, reporting of verification, validation, uncertainty quantification, and explicit context of use remains uneven and prospective clinical evidence is still limited. Overall, the literature shows rapid progress toward clinically credible HDTs, while highlighting the need for scalable computation, standardized credibility pipelines, and workflow-integrated platforms to support safe and reproducible clinical adoption.

Keywords: artificial intelligence | bibliometrics | clinical | decision-support systems | digital twin | human digital twin | patient specific modeling | precision medicine | surgical navigation systems | systems biology

Abstract: Spinal surgery demands exceptional theoretical knowledge and practical skills, with pedicle screw procedures posing significant risks due to proximity to critical anatomical structures. This study validates a virtual reality (VR) simulation platform for training in pedicle screw arthrodesis using patient-specific vertebral drilling templates. The practical simulation of a specific case study was evaluated with both neurosurgical residents and medical students. Results demonstrate that while experienced residents completed simulated procedures significantly faster than students (p < 0.01), these latter ones showed marked improvement across consecutive training sessions (p < 0.001). The most substantial performance gains occurred between the first and second trials, highlighting the rapid learning curve facilitated by the VR environment. System Usability Scale assessments revealed high satisfaction with the simulation platform, with participants emphasizing the value of risk-free repetitive practice. Qualitative feedback from experienced participants confirmed the precision and realism of the training environment as critical factors contributing to their efficiency. This validation confirms that VR simulation platforms offer an effective training environment for complex spinal procedures, providing a safe space for skill development before clinical application, particularly when incorporating innovative surgical aids such as patient-specific drilling templates.

Keywords: Pedicle screw insertion | Surgical template | Training | Vertebra | Virtual reality

Abstract: Background: This study investigated the biomechanical and physiological demands of the hiking position in Laser sailing, a posture requiring sailors to extend their upper bodies outside the boat to counter wind-induced heeling. This study utilized a mixed-methods approach. Methods: Twenty-two experienced Laser sailors participated in both on-land and offshore assessments. The study combined subjective discomfort ratings, biomechanical measurements, digital human modeling, and muscle activation analysis to evaluate the effects of hiking during and after exertion. Results: A two-way ANOVA showed significant effects by body region and time. The quadriceps, abdominals, and lower back reported the highest discomfort. Key postural angles were identified, including knee and hip flexion, trunk inclination, and ankle dorsiflexion. Muscle activation analysis revealed the highest engagement in the rectus abdominis (46.1% MVC), brachialis (~45%), and psoas major (~41%), with notable bilateral asymmetries. The trunk region had the highest overall activation (28.7% MVC), followed by the upper limbs (~18.7%), while the lower limbs were minimally engaged during static hiking. Conclusions: On-water conditions resulted in greater variability in joint angles, likely reflecting wind fluctuations and wave-induced boat motion. Findings highlight the quadriceps, abdominals, and lower back as primary contributors to sustained hiking, while also emphasizing the importance of targeted endurance training and ergonomic equipment design. These insights can guide training, recovery, and ergonomic strategies to optimize performance and reduce injury risk in Laser sailors.

Keywords: biomechanics | digital human modeling | hiking | laser sailing | muscle fatigue | physical strain | postural discomfort

Abstract: Background and objective: Accurately measuring cervical vertebrae dimensions is crucial for diagnosing conditions, planning surgeries, and studying morphological variations related to gender, age, and ethnicity. However, traditional manual measurement methods, due to their labour-intensive nature, time-consuming process, and susceptibility to operator variability, often fall short in providing the objectivity required for reliable measurements. This study addresses these limitations by introducing a novel computer-based method for automatically identifying the dimensional features of human cervical vertebrae, leveraging 3D geometric models obtained from CT or 3D scanning. Methods: The proposed approach involves defining a local coordinate system and establishing a set of rules and parameters to evaluate the typical dimensional features of the vertebral body, foramen, and spinous process in the sagittal and coronal planes of the high-density point cloud of the cervical vertebra model. This system provides a consistent measurement reference frame, improving the method's reliability and objectivity. Based on this reference system, the method automates the traditional standard protocol, typically performed manually by radiologists, through an algorithmic approach. Results: The performance of the computer-based method was compared with the traditional manual approach using a dataset of nine complete cervical tracts. Manual measurements were conducted following a defined protocol. The manual method demonstrated poor repeatability and reproducibility, with substantial differences between the minimum and maximum values for the measured features in intra- and inter-operator evaluations. In contrast, the measurements obtained with the proposed computer-based method were consistent and repeatable. Conclusions: The proposed computer-based method provides a more reliable and objective approach for measuring the dimensional features of cervical vertebrae. It establishes a procedural standard for deducing the morphological characteristics of cervical vertebrae, with significant implications for clinical applications, such as surgical planning and diagnosis, as well as for forensic anthropology and spinal anatomy research. Further refinement and validation of the algorithmic rules and investigations into the influence of morphological abnormalities are necessary to improve the method's accuracy.

Keywords: Biomedical engineering | Cervical vertebrae | CT measures standardization

Abstract: In the evolving landscape of driving training, the integration of technology has played a pivotal role in shaping educational methodologies and enhancing learning outcomes. Virtual training methods, which often rely on the use of monitors, have been the standard for decades. However, with the advent of augmented reality (AR), a new dimension of interactive and immersive training is emerging, promising to revolutionize the way driving skills are taught and acquired. This paper aims to explore and compare the effectiveness of virtual monitor-based training with the innovative use of augmented reality in driving simulations. The focus is on understanding how each method affects learning efficiency, user engagement, and the practical applicability of the skills acquired through these training modalities. Virtual monitor-based training systems are valued for their accessibility and cost-effectiveness, making them a prevalent choice in many training programs. On the other hand, augmented reality introduces a layer of interactive elements that overlay the real world or simulated environments, providing real-time feedback and enhancing situational awareness. This paper seeks to delineate the strengths and limitations of the AR-integrated driving training simulations. The goal is to provide insights into how virtual-based training can be optimized to enhance the safety, efficiency, and effectiveness of driving education, ultimately contributing to better-prepare drivers in their driving performances.

Keywords: Augmented Reality | Driving Simulator | User Experience

Abstract: Parkinson's disease (PD) is the second most common progressive degenerative disease after Alzheimer's disease, and occurs mainly in the population over 65 years of age. This disease, which is usually detected at an advanced stage, depends on a dysfunction of neuronal circuits comprising the motor cortical areas and the basal ganglia, resulting in movement abnormalities. This has a substantial impact on quality of life and requires various strategic treatments, including drug therapy, surgery and rehabilitation. This research work proposes a parametric multibody digital-twin model, developed in the Simulink-Simscape environment, capable of reproducing the posture and movements of PD patients. The model allows an accurate and non-invasive real-time or delayed assessment of patients’ movements, with the aim of identifying the main signs of disease progression at an early stage in order to prevent possible related risk factors and delay disease progression. The proposed method therefore makes it possible to perform, even at a distance, an assessment of the progress and level of severity of the disease, as well as early screening, through the digital monitoring of the maneuvers and clinical tests of the MDS-Unified Parkinson's Disease Rating Scale.

Keywords: Disease rating scale | Impaired motor control | Multibody digital-twin model | Neurodegenerative disease | Parkinson disease

Abstract: In the realm of cardiac health research, accurate fluid dynamics simulations are vital for comprehending the heart function and diagnosing conditions. Central to these simulations is the precision of ventricular wall meshes used to model heart geometry. However, segmenting the wetted surface, particularly in the right ventricle (RV) with its significantly thinner parietal thickness compared to the left ventricle, presents challenges. This study focuses on qualitatively evaluating an automated reconstruction model for the RV’s outer wall using Radial Basis function (RBF) morphing. Two procedural criteria were compared, a random selection of control points and a curvature-based approach, which differ in terms of the identification of the control points of the RBF function. From these considerations, it emerges that a controlled use of the RBF function on the basis of the curvatures guarantees the greater controllability of the shape evolutions of the parietal structure of the RV, but it is more sensitive to any anomalies in the distribution of the vertices, as can be seen from the number of outliers, and its controllability is a function of the percentage of points chosen, exerting a greater impact on the required computational capacity. The definition of a strategic criterion for the selection of control points could represent a crucial aspect in the definition of an automatic reconstruction procedure of anatomical elements, which guarantees a morphological variability in line with the need to expand the pathological sample to be used for statistical formulations in the clinical field.

Keywords: morphing | radial basis functions | right ventricle

Abstract: A procedure for reconstructing the central axis from diagnostic image processing is presented here, capable of solving the widespread problem of stepped shape effect that characterizes the most common algorithmic tools for processing the central axis for diagnostic imaging applications through the development of an algorithm correcting the spatial coordinates of each point belonging to the axis from the use of a common discrete image skeleton algorithm. The procedure is applied to the central axis traversing the vascular branch of the cerebral system, appropriately reconstructed from the processing of diagnostic images, using investigations of the local intensity values identified in adjacent voxels. The percentage intensity of the degree of adherence to a specific anatomical tissue acts as an attraction pole in the identification of the spatial center on which to place each point of the skeleton crossing the investigated anatomical structure. The results were shown in terms of the number of vessels identified overall compared to the original reference model. The procedure demonstrates high accuracy margin in the correction of the local coordinates of the central points that permits to allocate precise dimensional measurement of the anatomy under examination. The reconstruction of a central axis effectively centered in the region under examination represents a fundamental starting point in deducing, with a high margin of accuracy, key informations of a geometric and dimensional nature that favours the recognition of phenomena of shape alterations ascribable to the presence of clinical pathologies.

Keywords: Medial axis | Medical Imaging | Morphological analysis | Vessel reconstruction

Abstract: The present research work intends to examine the anatomical distribution of cerebral vessels, starting from the automatic processing of diagnostic image acquisition sequences, with the aim of identifying the characteristic parameters of their structural conformation, such as terminal points and bifurcations, and statistic connotations closely associated with the formation of pathological phenomena. To do this, a local connectivity investigation was used which, starting from the reconstruction of the central axis crossing the vessels, elaborates a process of sequential ordering of each section with the aim of investigating the spatial conformation of the vessels structure, identifying branches and regions of origin. The proposed algorithm also elaborates a punctual analysis of the vascular branches, giving rise to a three-dimensional reconstruction of the morphological and topological characterization of the vessels in support of the clinical examination. The aim is to provide a fast and accurate procedure capable of automatically interpreting diagnostic analyses of brain vessels to support clinical investigation.

Keywords: 3D Reconstruction | Cerebral Vessels | Medial Axis | Medical Imaging | Minimum Spanning Tree

Abstract: The work here presented elaborates an analysis of the retinal images, with the aim of characterizing their morphological conformation through the recognition of remarkable parameters such as, among all, the number of vessels, terminal points and bifurcation. The correct identification of each single vessel belonging to the vascular distribution represents a point that has not yet been fully consolidated by the scientific community. The reason lies in the fact that the interpretation of enface images, in which the distribution of the vases is imprinted on a two-dimensional plane, makes it difficult to discern each single section of the vase by following its entire spatial development, due to the multiple overlaps with different pot portions. The aim of this research work is to ensure that the limits encountered in modern retinal image processing algorithms are overcome, through the use of an evaluative comparison of contiguous vessel portions on the basis of local dimensional and intensity similarity criteria. In this way, it is possible to trace the correct attribution of the spatial placement of each vessel, taking it into account in the relative classification in the entire vascular branch of clinical interest.

Keywords: Medical Imaging | Retina Fundus | Vessels Connectivity | Vessels Intersections

Abstract: In the field of medical image processing, the resolution capacity exhibited by the initial diagnostic investigations is becoming increasingly important. With respect to them, in fact, the row image set is subjected to three-dimensional reconstruction analysis, by partitioning the regions of interest, as well as to local investigations, aimed, for example, at the extrapolation of topological information, relating to the morphology of the object that needs to be investigated. The accuracy of these functions is, however, difficult to quantify, due to the lack of three-dimensional models that act as a reference Gold Standard. The reproduction of CT-type diagnostic acquisitions, starting from a virtual scanning procedure of a starting known three-dimensional geometry is used. To do this, triangular tessellated three-dimensional models of various geometries were examined. These were broken down into cubic elements, equal in size to those of a common voxel, thus resulting in a volume scan simulation of the original region considered. The structure thus obtained was then subjected to skeletonization and medial axis algorithms to evaluate the effectiveness of some of the most commonly used functions in medical processing. A virtual scanning model of this type can be an extremely effective evaluation analysis tool in discriminating the resolutive quality of the medical image processing functions. From a qualitative comparison of this type, it is possible to optimize automated anatomical investigation algorithms, making a significant contribution in the refinement of the techniques, now more and more demanding, of image processing in the biomedical field.

Keywords: Medical image acquisition | Thinning and Medial Axis | Voxelization

Abstract: The development of cutting-edge technologies in the industrial sector has led to the demand for increasingly specific tools in the optimization of efficiency problems. The automotive sector is the one that makes the most use of these technologies, such as, among all, Virtual Reality (VR) and Augmented Reality (AR). A virtual reality tool is inserted as a guide tool for the user in drawing as quickly as possible the key information for optimizing the process. This research work fits into this context, the goal of which was the implementation of an immersive platform for carrying out accurate measurements within an entirely virtual automotive environment. A VR system of this type allows to check the dimensional and shape tolerances of car components, performing measurement, with high precision and in real time, in a custom-made virtual environment, in which it is possible to simulate the presence of a myriad of components and test their mutual interaction. A comparative test was carried out, obtained by varying the graphical and geometrical model in the VR settings, in order to evaluate the level of usability and the degree of efficiency of a tool for measuring distances between objects in a virtual reality environment, depending on the system parameters. The validation of a measurement instrument in VR is part of an increasingly current technological context in which the need to optimize the time-cost curve embraces the need for increasingly accurate results.

Keywords: Assembly training | Tolerance measurements | Virtual reality

Abstract: In recent years, 3D printed scaffolds have been proposed as promising alternative to the conventional cell culture techniques. Scaffolds, indeed, allow the development of a higher number of cellular connections along the three dimensions favoring the cell regeneration, which make them particularly suitable in case of implants for deteriorate bones in old age patients. Besides the characteristics of biocompatibility and biodegradability fundamental for the integration of the scaffolds with the human body, the inner morphology, the permeability as well as the porosity are parameters of paramount relevance in the design of 3D-printed scaffolds influencing the flow of the blood through the cells and, thus, their metabolic functions. In the present work the influence of the internal geometry of 3D-printed scaffolds on the blood flow was investigated. Five cylindrical scaffolds having different internal geometry and different porosity were fabricated using parametric design technique. Numerical analysis of the blood flow within the designed structures was conducted by using CFD tool.

Keywords: additive manufacturing | blood flow simulation | bone scaffolds | parametric design | porous metal

Abstract: The introduction of Digital Human Modeling and Virtual Production in the industrial field has made possible to bring the user to the center of the project in order to guarantee the safety of workers and well-being in the performance of any activity. Traditional methods of motion capture are unable to represent user interaction with the environment. The user runs a simulation without the realistic objects, so his behavior and his movements are inaccurate due to the lack of real interaction. Mixed reality, through a combination of real objects and virtual environment, allows to increase the human-object interaction, improving the accuracy of the simulation. A real-time motion capture system produces considerable advantages: the possibility of modifying the action performed by the simulator in real time, the possibility of modifying the user’s posture and obtaining feedback on it, and finally, after having suffered a post-data processing, without first processing the recorded animation. These developments have introduced Motion Capture (MoCap) technology into industrial applications, which is used for assessing and occupational safety risks, maintenance procedures and assembly steps. However, real-time motion capture techniques are very expensive due to the required equipment. The aim of this work, therefore, is to create an inexpensive MoCap tool while maintaining high accuracy in the acquisition. In this work, the potential of the Unreal Engine software was initially analyzed, in terms of ergonomic simulations. Subsequently, a case study was carried out inside the passenger compartment of the vehicle, simulating an infotainment reachability test and acquiring the law of motion. This procedure was performed through two cheap MoCap techniques: through an optical system, using ArUco markers and through a markerless optical system, using the Microsoft Kinect® as a depth sensor. The comparison of the results showed an average difference, in terms of calculated angles, between the two methodologies, of about 2,5 degrees. Thanks to this small error, the developed methods allows to have a simulation in mixed reality with user’s presence and offers an accurate analysis of performed movements.

Keywords: ArUco markers | Digital human modelling | Mannequins | Mixed-reality | Motion capture | Realtime tracking | Unreal engine

Abstract: Spine surgery is based, nowadays, on the use of cutting-edge instruments that optimize the intervention processes in the operating room, with advantages that affect the patient himself. Among these, rapid prototyping is configured as a first-rate tool, thanks to its ability to detail the diagnostic treatment according to the specific pathological case under examination. An example of this technology is represented by the generation of a drilling template, to assist the surgeon in identifying the optimal direction of insertion of the pedicle screws, capable of significantly reduce intervention times, in addition to the inevitable exposure of the patient to ionizing radiation, to which he is subjected during a normal arthrodesis intervention procedure. The design of a drilling guide requires, however, a particular attention in identifying the undercuts present on the vertebral surface, those areas of the spinous process which, reported inside the cavity of the template, involve complications at the time of extraction. In parallel, it is vitally important to carry out an evaluation of its stability during its use. In this article, starting from the analysis of the interferences present during the insertion of the template, a semi-automatic correction model is proposed for the generation of a new profile of the same, which facilitates its extraction without causing injury to the vertebral regions involved from the contact with the mask.

Keywords: Computer‐assisted surgery | Pedicle screw fixation | Spine | Surgical template insertion optimization | Undercuts

Abstract: BACKGROUND: Nowadays, the ergonomic study of the driving position is a critical aspect of automotive design. Indeed, due to the rising needs on the market, one focus for car industries is to improve the perceived comfort related to the cars' interior. Driving a car for a prolonged time could cause complaints in some body-regions, especially in the lumbar-sacral area. Thus, special lumbar-sacral supports for driver seat has been proposed for reducing this kind of complaints. OBJECTIVE: Development of two virtual and physical models of lumbar-sacral support for improving both the lumbar/sacral and overall perceived comfort while driving. METHODS: Two prototypes of lumbar/sacral support have been realized: the first one was integrated into the seat, and the second one was shaped as a removable pillow (removable support). Fifty participants were asked to rate the perceived comfort in lab tests performed on a seating-buck by comparing three configurations (5 min each): a standard seat, seat with the removable support, seat with integrated support. Subjective data (by questionnaires) and objective data (interface pressure between backrest and driver) have been acquired and statistically processed. In addition, real driving tests have been performed to test the actual performance of the removable support in term of perceived comfort comparing it with the standard seat. RESULTS: Statistical correlations between subjective and objective data showed interesting results in comfort improvement through the adopted solutions. Real driving tests showed an improvement in comfort perception with the lumbar-sacral support towards the standard seat. CONCLUSIONS: Thanks to the virtual prototyping and the application of previous knowledge, coming from literature and experience, a solution for improving the overall comfort and reduce the lumbar/sacral pain while driving has been developed, tested, and assessed.

Keywords: body-shaped pillow | Car seat comfort | lumbar-sacral support | seat design

Abstract: Background: The integration of computer-aided design/computer-aided manufacturing (CAD/CAM) tools and medicine is rapidly developing for designing medical devices. A novel design for a 3D-printed patient-specific surgical template for thoracic pedicle screw insertion, using a procedure based on reverse engineering, is presented. Methods: The surgeon chooses the entry point on the vertebra. The optimal insertion direction and the size of the screws are defined via an algorithm on the basis of a patient-specific vertebra CAD model. The template features an innovative shape for a comfortable and univocal placement and a novel disengaging device. Results: Three spinal fusions were performed to test the template. Excellent results were achieved in terms of the accuracy of the screw positioning, reduction in surgery duration, and number of X-rays. Conclusions: A novel design for a customized, 3D-printed surgical template for thoracic spinal arthrodesis was presented, and improvements in terms of precision, duration, and safety were achieved without changing the standard procedure.

Keywords: 3D imaging | additive manufacturing | bone | computer-assisted surgery | imaged guided surgery | in vivo | modelling | pedicle screw fixation | screw direction optimization | spine | surgical template | thoracic | thoracic spinal arthrodesis | X-ray minimization