Three-dimensional scanning technology has been traditionally used in the medical and engineering industries, but these scanners can be expensive or limited in their capabilities. This research aimed ...to develop low-cost 3D scanning using rotation and immersion in a water-based fluid. This technique uses a reconstruction approach similar to CT scanners but with significantly less instrumentation and cost than traditional CT scanners or other optical scanning techniques. The setup consisted of a container filled with a mixture of water and Xanthan gum. The object to be scanned was submerged at various rotation angles. A stepper motor slide with a needle was used to measure the fluid level increment as the object being scanned was submerged into the container. The results showed that the 3D scanning using immersion in a water-based fluid was feasible and could be adapted to a wide range of object sizes. The technique produced reconstructed images of objects with gaps or irregularly shaped openings in a low-cost fashion. A 3D printed model with a width of 30.7200 ± 0.2388 mm and height of 31.6800 ± 0.3445 mm was compared to its scan to evaluate the precision of the technique. Its width/height ratio (0.9697 ± 0.0084) overlaps the margin of error of the width/height ratio of the reconstructed image (0.9649 ± 0.0191), showing statistical similarities. The signal-to-noise ratio was calculated at around 6 dB. Suggestions for future work are made to improve the parameters of this promising, low-cost technique.
The optimal reconstruction parameters of spherical harmonic (SH) series for the aggregates with different morphologies and sizes were not clear. In this paper, manufactured aggregates with different ...sizes (1.18–2.36 mm, 2.36–4.75 mm, 4.75–9.50 mm), and natural aggregate with size >1.18 mm were scanned using the digital light projection (DLP), and reconstructed using SH series. The effect of maximum number of SH functions (N) used in the reconstruction series and the number of terms in the Gaussian quadrature (G) used for solving the SH expansion coefficients on the reconstruction errors were studied. The optimal reconstruction parameters for different particle sizes and morphologies were proposed, via a derived relationship between N and G. The reconstruction errors decreased when the N and G values increased. The relationship between N and G was derived to be G ≥ 1.84 N + 3.60, which is probably caused by the issue of the algebraic precision of the Gaussian integral.
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•The inter-relation of N and G on reconstruction accuracy was analyzed.•The minimum number of SH functions for different aggregate size was proposed.•A relationship between N and G was developed to ensure reconstruction accuracy.
•Affordable 3D scanning and printing enables pinna replication for HRTF measurements.•Two printing materials yield accurate replicas, though harder one deviates at 2 kHz.•Perceptual discrimination ...between standardized and 3D printed pinnae is challenging.•Soft flexible printing material outperforms a harder alternative.
An important application of a head and torso simulator is to obtain head-related transfer functions (HRTFs) because it eliminates the methodological challenges inherent in human-based measurements. However, the use of these non-individual HRTFs to simulate virtual environments can lead to sound source localization errors in the listener. The emerging 3D scanning and printing technology make it possible to fabricate such intricate elements as the outer ear, thus several studies were initiated to explore the fabrication of individual dummy heads for various uses in acoustics. In this study we evaluate the feasibility of using low-cost 3D scanning and printing technology in the replication of human pinnae for use in HRTF measurements. A pair of commercially available standardized pinna simulators (silicone-rubber material) was scanned with a 3D scanner. Then two replicas were printed using two easily accessible materials of different hardnesses: acrylonitrile butadiene styrene (ABS, hard material) and thermoplastic polyurethane (TPU, soft material). A set of HRTFs was measured for each pair of pinnae to perform technical and perceptual evaluations, taking the commercial one as a reference. First, a numerical evaluation and a binaural cues analysis were performed on the HRTFs, followed by a psychophysical experiment of discrimination between auralized stimuli with the different HRTFs. The findings revealed overall similarities between the reference pinna and both replicas, leading to difficulties in their perceptual discrimination. However, the flexible soft material (TPU) demonstrated superior performance in both the technical and psychophysical validations. This discrepancy seems mostly attributable to a superior fit of the pinna with the head simulator. The harder material (ABS) had small irregularities in the fit preventing the formation of a resonance tube of adequate length to effectively reproduce the ear canal. These findings indicate the effectiveness of affordable 3D technology in the construction of pinna simulators for HRTF measurements as an alternative for commercial ones.
A significant number of the research paper on Medical cases using Additive manufacturing studied. Different applications of additive manufacturing technologies in the medical area analysed for ...providing the state of the art and direction of the development.
To illustrate the Additive Manufacturing technology as being used in medical and its benefits along-with contemporary and future applications.
Literature Review based study on Additive Manufacturing that are helpful in various ways to address medical problems along with bibliometric analysis been done.
Briefly described the review of forty primary applications of AM as used for medical purposes along with their significant achievement. Process chain development in the application of AM is identified and tabulated for every process chain member, its achievement and limitations for various references.
There are five criteria which one can achieve through medical model when made through AM technology. To support the achievements and limitations of every criterion proper references are provided. The ongoing research is also classified according to the application of AM in medical with criteria, achievement and references. Eight major medical areas where AM is implemented have been identified along with primary references, objectives and advantages.
Paper deals with the literature review of the Medical application of Additive Manufacturing and its future. Medical models which are customised and sourced from data of an individual patient, which vary from patient to patient can well be modified and printed. Medical AM involves resources of human from the field of reverse engineering, medicine and biomaterial, design and manufacturing of bones, implants, etc. Additive Manufacturing can help solve medical problems with extensive benefit to humanity.
•Conduct a non-contact 3D Scanning Laser Doppler Vibrometer (SLDV) test on a three-bladed wind turbine assembly.•Develop a finite element model of the assembly including the composite blade ...modeling.•Correlate modal parameters and dynamic response between the SLDV test and the finite element model.•Investigate high-order complex curvature mode shapes and mode coupling of the wind turbine blade through both experimental and numerical approach.
Experimental and numerical modal analysis on wind turbine blades has been previously studied, considering mainly low order bending modes. However, high-order modes are also critical modes for understanding blade dynamics. The mode coupling is essential because a better understanding of the high-frequency blade dynamics can support advances in model validation, blade aeroelastic simulations, blade design, and structural health monitoring. However, these high-order modes and the associated mode couplings of wind turbine blades have not been studied. This work presents a comprehensive experimental and numerical study based on three modal tests and a correlated finite element simulation to study the complex curvature mode shapes and mode coupling dynamics for a three-bladed wind turbine assembly. Three tests are conducted: Test 1, ten accelerometers are deployed on the whole assembly under impact excitation; Test 2, nine accelerometers are deployed on a single blade under impact excitation; and Test 3, a non-contact 3D Scanning Laser Doppler Vibrometer (SLDV) test is performed on a single blade under shaker excitation. This is the first work to use a 3D SLDV for an experimental modal test on the wind turbine blade. With 300–400 points measured with the 3D SLDV, experimental mode shapes having a high spatial resolution with 3D response are used to characterize the coupling for the low-order and high-order modes with complex curvatures. A reliable finite element model of the three-bladed assembly, including the composite blade modeling, is also developed and is well correlated with Test 2 and Test 3. With the high-fidelity 3D SLDV test and well-correlated finite element model, this is also the first work of using experimental and numerical approaches to investigate the high-order mode shape with complex curvatures and mode coupling of bending and torsional behavior that is present in the wind turbine blade for these high-order modes.
Three-dimensional (3D) scanning technologies, such as medical imaging and surface scanning, have important applications for capturing patient anatomy to create personalised prosthetics. Digital ...approaches for capturing anatomical detail as opposed to traditional, invasive impression techniques significantly reduces turnaround times and lower production costs while still maintaining the high aesthetic quality of the end product. While previous case studies utilise expensive 3D scanning and modelling frameworks, their clinical translation is limited due to high equipment costs. In this study, we develop and validate a low-cost framework for clinical 3D scanning of the external ear using photogrammetry and a smartphone camera. We recruited five novice operators who watched an instructional video before scanning 20 healthy adult participant ears who did not have microtia.
Our results show that the smartphone-based photogrammetry methodology produces 3D scans of the external ear that were accurate to (1.5 ± 0.4) mm and were (71 ± 14) % complete compared with those from a gold standard reference scanner, with no significant difference observed between operators. A moderate to strong interrater reliability was determined for all novice operators, suggesting that all novice operators were able to capture repeatable scans. The development of this smartphone photogrammetry approach has the potential to provide a non-invasive, inexpensive and accessible means to capture patient morphology for use in clinical assessment and personalised device manufacture, specifically for ear prostheses. We also demonstrate that inexperienced operators can rapidly learn and apply smartphone photogrammetry for accurate and reliable scans of the external ear with important applications for future clinical translation.
Structured light three-dimensional (3D) scanning is a ubiquitous mainstay of object inspection and quality control in industrial manufacturing, and has recently been integrated into various medical ...disciplines. Photorealistic 3D scans can readily be acquired from fresh or formalin-fixed tissue and have potential for use within anatomic pathology (AP) in a variety of scenarios, ranging from direct clinical care to documentation and education. Methods for scanning and post-processing of fresh surgical specimens rely on relatively low-cost and technically simple procedures. Here, we demonstrate potential use of 3D scanning in surgical pathology in the form of a mixed media pathology report with a novel post-scan virtual inking and marking technique to precisely demarcate areas of tissue sectioning and details of final tumor and margin status. We display a sample mixed-media pathology report (3D specimen map) which integrates 3D and conventional pathology reporting methods. Finally, we describe the potential utility of 3D specimen modeling in both didactic and experiential teaching of gross pathology lab procedures.
•Corrosion of reinforcing steel bars in chloride contaminated concrete is investigated experimentally.•Pitting corrosion of 50 corroded steel bars were analysed using statistical analysis ...methods.•Probability distributions of pit depth, residual cross-section area and second moments of area are discussed.•Correlations between pit depth, residual cross-section area and smaller principal second moments of area are examined.
This paper experimentally investigates the pit corrosion of steel bars in chloride contaminated concrete. The obtained 3-D images of the corroded bars are analyzed using statistical methods. The results show that the pit depth, residual cross-section area and smaller principal moment of inertia of plane area have multiple probability distribution patterns. The correlation of the pit depth with the mass loss is weak. The statistically obtained locations where the minimum residual cross-section area and minimum smaller principal moment of inertia of plane area are located are found to be close, suggesting this is the weakest section where the corroded bar will likely fail.
•A 3D scanner is a non-contact, non-destructive digital device that uses a light/laser source to accurately capture the shape of a physical object into computer-aided design (CAD) data.•It generates ...a point cloud or a set of data points in a coordinate system that accurately depicts a physical object's size and shape.•Using different methods, 3D scanning can collect information about an item, about an object's highness, breadth, and depth.•This paper discusses 3D Scanning, its processes, and its adoption for reverse engineering and industry 4.0 culture.•Finally, this paper covers essential features, traits, and applications of 3D scanning for the industry 4.0 environment.
A 3D scanner is a non-contact, non-destructive digital device that uses a light line/laser to accurately capture the shape of a physical object into Computer-Aided Design (CAD) data. It generates a point cloud or a set of data points in a coordinate system that accurately depicts a physical object's size and shape. The urge of human beings to build and recreate 3D objects is an essential requirement in the context of Industry 4.0. In Industry 4.0, 3D scanners are helpful for designing, assessing the minor features of any product, capturing freeform, and providing precise point clouds for complicated geometry and curved surfaces. Today advanced technologies are being introduced in industries, and 3D scanning technology is one of the latest emerging technologies. The situation has progressed significantly, and the ever-emerging world of 3D technology still disrupts a variety of sectors. This paper discusses 3D Scanning, its working process, and its adoption for reverse engineering and Industry 4.0 culture. Finally, this paper covers essential features, traits, and applications of 3D Scanning for Industry 4.0. Using different methods, 3D Scanning can collect information about an item, about an object's highness, breadth, and depth. 3D scanners are available on the market from high-end possibilities. They have different resolutions, and now they provide details of the scan to superimpose colour on an object, but the industry wants them to be developed for other quality attributes.
A 3D printing methodology for the design, optimization, and fabrication of a custom nerve repair technology for the regeneration of complex peripheral nerve injuries containing bifurcating sensory ...and motor nerve pathways is introduced. The custom scaffolds are deterministically fabricated via a microextrusion printing principle using 3D models, which are reverse engineered from patient anatomies by 3D scanning. The bifurcating pathways are augmented with 3D printed biomimetic physical cues (microgrooves) and path‐specific biochemical cues (spatially controlled multicomponent gradients). In vitro studies reveal that 3D printed physical and biochemical cues provide axonal guidance and chemotractant/chemokinetic functionality. In vivo studies examining the regeneration of bifurcated injuries across a 10 mm complex nerve gap in rats showed that the 3D printed scaffolds achieved successful regeneration of complex nerve injuries, resulting in enhanced functional return of the regenerated nerve. This approach suggests the potential of 3D printing toward advancing tissue regeneration in terms of: (1) the customization of scaffold geometries to match inherent tissue anatomies; (2) the integration of biomanufacturing approaches with computational modeling for design, analysis, and optimization; and (3) the enhancement of device properties with spatially controlled physical and biochemical functionalities, all enabled by the same 3D printing process.
An imaging‐coupled 3D printing methodology for the design, optimization, and fabrication of a customized nerve repair technology for complex injuries is presented. The custom scaffolds are deterministically fabricated via microextrusion printing, which enables the simultaneous incorporation of anatomical geometries, biomimetic physical cues, and spatially‐controlled biochemical gradients in a one‐pot 3D manufacturing approach.
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