Sandro Barone

Bio: Sandro Barone is an academic researcher from University of Pisa. The author has contributed to research in topics: Structured light & Photoelasticity. The author has an hindex of 20, co-authored 91 publications receiving 1284 citations. Previous affiliations of Sandro Barone include University of Sheffield.

An alternative finite difference method for post-processing thermoelastic data using compatibility

Abstract: A finite difference technique for processing thermoelastic data for biaxial problems is presented. The method enables thermoelastic data to be smoothed at interior points and boundary information to be calculated from measured non-boundary values by an iterative procedure based on the compatibility equation. The technique has been successfully applied to quantify stress concentrations and to perform stress separation.

Sensor Architectures and Technologies for Upper Limb 3D Surface Reconstruction: A Review.

Abstract: 3D digital models of the upper limb anatomy represent the starting point for the design process of bespoke devices, such as orthoses and prostheses, which can be modeled on the actual patient's anatomy by using CAD (Computer Aided Design) tools. The ongoing research on optical scanning methodologies has allowed the development of technologies that allow the surface reconstruction of the upper limb anatomy through procedures characterized by minimum discomfort for the patient. However, the 3D optical scanning of upper limbs is a complex task that requires solving problematic aspects, such as the difficulty of keeping the hand in a stable position and the presence of artefacts due to involuntary movements. Scientific literature, indeed, investigated different approaches in this regard by either integrating commercial devices, to create customized sensor architectures, or by developing innovative 3D acquisition techniques. The present work is aimed at presenting an overview of the state of the art of optical technologies and sensor architectures for the surface acquisition of upper limb anatomies. The review analyzes the working principles at the basis of existing devices and proposes a categorization of the approaches based on handling, pre/post-processing effort, and potentialities in real-time scanning. An in-depth analysis of strengths and weaknesses of the approaches proposed by the research community is also provided to give valuable support in selecting the most appropriate solution for the specific application to be addressed.

A reverse engineering methodology to capture complex shapes

Abstract: This paper presents a research activity concerning the development of a non-contact scanning system based on combining structured light with stereo vision. A methodology is proposed to establish reliable dense correspondences among a pair of cameras on the basis of vertical and horizontal coded fringe patterns. The methodology can efficiently be used to measure freeform shapes, which typically do not present peculiarities usable by classical correlation procedures. The proposed technique is the core of a complete 3D shape measurement framework, which also includes a multi-scan procedure to reconstruct complex surfaces. In this work, the system has been successfully used to measure styling surfaces of sport cars. In particular, the methodology has been applied to acquire and model the shapes of a scaled vehicle prototype, typically, used for aerodynamic tests in wind tunnel.

Mechanical and Geometrical Properties Assessment of Thermoplastic Materials for Biomedical Application

Abstract: Clear thermoplastic aligners are nowadays widely used in orthodontics for the correction of malocclusion or teeth misalignment defects. The treatment is virtually designed with a planning software that allows for a definition of a sequence of little movement steps from the initial tooth position to the final desired one. Every single step is transformed into a physical device, the aligner, by the use of a 3D printed model on which a thin foil of plastic material is thermoformed. Manufactured aligners could have inherent limitations such as dimensional instability, low strength, and poor wear resistance. These issues could be associated with material characteristics and/or with the manufacturing processes. The present work aims at the characterization of the manufactured orthodontic devices. Firstly, mechanical properties of different materials have been assessed through a set of tensile tests under different experimental conditions. The tests have the purpose of analyzing the effect that the forming process and the normal use of the aligner may have on mechanical properties of the material. The manufacturing process could also introduce unexpected limitations in the resulting aligners. This would be a critical element to control in order to establish resulting forces on teeth. Several studies show that resulting forces could be greatly influenced by the aligner thickness. A method to easily measure the actual thickness of the manufactured aligner is proposed. The analysis of a number of real cases shows as the thickness is far to be uniform and could vary strongly along the surface of the tooth.

Grid pattern for in-plane strain measurements by digital image processing

Abstract: This paper presents a non-contact and non-destructive method for full-field in-plane strain measurements. Digital image processing is employed for monitoring the deformations of grid lines marked on a planar surface of a component or a specimen. Full-field in-plane strain distributions are obtained by processing the geometrical characteristics of the grid with computer graphics algorithms. The strain field determined in the necking zone of a tensile specimen has demonstrated the benefit of the method.

The Act of Creation

Abstract: While the study of psychology has offered little in the way of explaining the creative process, Koestler examines the idea that we are at our most creative when rational thought is suspended--for example, in dreams and trancelike states. All who read The Act of Creation will find it a compelling and illuminating book.

A review on stereolithography and its applications in biomedical engineering

Abstract: Stereolithography is a solid freeform technique (SFF) that was introduced in the late 1980s Although many other techniques have been developed since then, stereolithography remains one of the most powerful and versatile of all SFF techniques It has the highest fabrication accuracy and an increasing number of materials that can be processed is becoming available In this paper we discuss the characteristic features of the stereolithography technique and compare it to other SFF techniques The biomedical applications of stereolithography are reviewed, as well as the biodegradable resin materials that have been developed for use with stereolithography Finally, an overview of the application of stereolithography in preparing porous structures for tissue engineering is given