1,720,986 research outputs found
Comfort driven design of innovative products: A personalized mattress case study
No full textBACKGROUND: Human-centred design asks for wellbeing and comfort of the customer/worker when interacting with a product. Having a good perception-model and an objective method to evaluate the experienced (dis)comfort by the product user is needed for performing a preventive comfort evaluation as early as possible in the product development plan. The mattress of a bed is a typical product whose relevance in everyday life of people is under-evaluated. Fortunately, this behaviour is quickly changing, and the customer wants to understand the product he/she buys and asks for more comfortable and for scientifically assessed products. No guidelines for designing a personalized mattress are available in the literature. OBJECTIVES: This study deals with the experience of designing an innovative product whose product-development-plan is focused on the customer perceived comfort: a personalized mattress. The research question is: which method can be used to innovate or create a comfort-driven human-centred product? METHODS: Virtual prototyping was used to develop a correlated numerical model of the mattress. A comfort model for preventively assessing the perceived comfort was proposed and experimentally tested. Mattress testing sessions with subjects were organized, and collected data were compared with already tested mattresses. Brainstorming and multi-expert methods were used to propose, realize, and test an archetype of a new mattress for final comfort assessment. RESULTS: A new reconfigurable mattress was developed, resulting in two patents. The mattress design shows that personalized products can be tuned according to the anthropometric data of the customer in order to improve the comfort experience during sleep. CONCLUSIONS: A 'comfort-driven design guideline' was proposed; this method has been based on the use of virtual prototyping, virtual optimization and physical prototyping and testing. It allowed to improve an existing product in a better way and to bring innovation in it
A novel procedure for medial axis reconstruction of vessels from Medical Imaging segmentation
Full text linkA 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
Assessment of ranges of rest postures of human lower limbs
No full textBACKGROUND: Several comfort perception models have proposed an objective method to evaluate 'effects in the internal body' and 'perceived comfort'. Postural comfort is one aspect of comfort/discomfort perception, and this current work adds to existing knowledge toward a more objectified posture evaluation for comfort. OBJECTIVE: The authors have used the concept of Range of Rest Posture (RRP), as proposed by Apostolico et al. The study focused on the identification of RRP within the Comfort Range of Motion (CROM) for lower limbs. METHODS: The proposed method is based on extensive experimental work involving 114 healthy individuals (59 males and 55 females) ranging from 20 to 40 years old. The age range was narrowed to avoid an age-clustering of results due to inhomogeneity of the statistical sample. Data were processed using statistical methods for identifying the RRP in the experimental CROM. Several Maximum Level of Comfort (MLC) positions were found within the RRP. RESULTS: RRPs for lower limbs of men and women have been identified and can be used for virtual comfort assessment. CONCLUSIONS: This paper shows a method to evaluate in a more objective way the subjective postural comfort perception and results allow researchers to improve models for the virtual preventive comfort assessment
Sulle Procedure di Modellazione Tipizzata 3D per la Valutazione dei Fattori di Intensità delle Tensioni da Cricche Superficiali
No full textCerebral Vessels Diagnostic Investigation: Vessel Classification from Medial Axis Evaluation
No full textMulti-target driven design of a smart aircraft accessibility system for people with reduced mobility: the BEAIR® project
No full textThe number of persons with disabilities represents a significant part of world’s population. There
are more than 1 billion people with disability that is about 15% of the world’s population or one in seven people.
In Europe, there are around 80 million persons with disabilities (physical disabilities 72.5%). On the other
hand, population aging in Europe, along with the high correlation between age and disability, implies that the
share of the disables among the European citizens is bound to increase significantly. With regard to transport,
the lack of accessibility contributes to the disadvantages experienced by people with disability. The paper
shows a multi-target driven design of a smart aircraft accessibility system for people with reduced mobility
(the BEAIR®) in which the comfort assessment has been made through the explicit FEM simulation approach.
Obtained results have been compared with values coming from literature. The development of the
BEAIR® concept has been initiated by making use of the Quality Function Deployment (QFD) approach,
which has led to the identification of the key equipment characteristics, in fulfillment to the applicable regulations
and laws, as well as to the stakeholders needs (the PRM, Passenger with reduced mobility). Among the
needs, one of the most relevant is the mitigation of the bedsores problem, which occurs mainly when the PRM
is subjected to long haul flight. To mitigate the said issue, and properly address the design of cushion, a simulated
ergonomic analysis has been performed as described in the present paper, prior qualification and ergonomic
tests. The simulation has been iterated so to achieve an optimal design in shape, material and stiffness
of the cushion
Methodologies for assessing the quality of 3D models obtained using close-range photogrammetry
Full text linkAlthough reality-based models are widely used to describe the geometric surfaces of an entity in a digital space, a systematic and universally recognised treatment of issues such as accuracy is lacking. The topic is certainly complex as this analysis should involve not only shape approximation but also other attributes (e.g., colour). Wanting to limit ourselves to geometry alone, this work proposes solutions for assessing the quality of photogrammetric models, differentiating them according to possible scenarios: sometimes, homologous models obtained using different techniques and technologies are available. In these cases, a comparison between digital reconstructions can serve to effectively quantify accuracy; more often, no terms of comparison are available, and one is forced to derive indicators from the same photogrammetric process to describe quality. We propose for this scenario a statistical analysis on the covariance matrix of the estimated coordinates for the tie points. The main goal is to provide a range of possible approaches to the conscious management of survey data
Analysis of the influence of inner morphology on blood flow in 3D-printed bone scaffolds
No full textIn 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
Reachability Simulation of Car Dashboard Commands: A Comparison Between DelmiaTM v5 and Unreal EngineTM v4
No full textThe aim of this study is to provide an example of a methodology to simulate human–machine interaction in human centric design approach for performing ergonomics and (dis)comfort analyses. It consists of gathering data from the real world, creating a virtual model of the environment and a digital human model, and finally simulating interactions with artefacts and human body-parts motions in different software applications. Firstly, motion capture has been carried out using a low-cost motion-capture system with markers and cameras, then data acquired have been processed using Python© and MATLAB© codes to extract useful information about the movements. This information has been processed to recreate the movements in a virtual environment using DELMIATM and Unreal EngineTM. Both methods proved their reliability in testing reachability, but the comparison showed that Unreal EngineTM appears much more realistic in manikin and movements’ simulations than DELMIATM. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG
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