3D Scanning Research Articles

Microsurgical Anatomy of the Common Tendinous Ring and Its Surgical Implications

BACKGROUND AND OBJECTIVES: The common tendinous ring (CTR), also known as the common annular tendon or annulus of Zinn, is a critical anatomic structure located at the convergence of the orbital apex, superior orbital fissure (SOF), optic canal, and the anterior aspect of the lateral sellar compartment. It plays a vital role in both neurosurgical and neuro-ophthalmological interventions. The aim of this study was to delineate the complex 3-dimensional (3D) topography of the CTR and explore its implications for surgical procedures. METHODS: Ten formalin-fixed skull base specimens from adult Chinese cadavers were meticulously dissected to investigate the morphology of the CTR, focusing particularly on its relationship with the 4 extraocular rectus tendons, the optic strut, the SOF, and the optic canal. Additional skull base specimens were subjected to 3D surface scanning, computed tomography, and histopathological examinations to deepen our understanding of the CTR's structural complexities. RESULTS: The CTR establishes a spatial, 3D tendinous assembly, encompassing 4 rectus tendons, 2 tendinous connections, and a singular common tendinous root. These components interlink to form a distinctive dual-ring configuration, featuring the optic foramen and the oculomotor foramen. The posterior part of the superior rectus tendon demarcates the common boundary between these 2 foramina. The oculomotor foramen itself serves as the central sector of the SOF. Precise incisions of the medial and lateral tendinous connections and fusions are essential for safely opening the CTR. CONCLUSION: The structural composition, interconnections, and dual-ring configuration of the CTR are crucial for precise and safe surgery of orbital apex and adjacent regions.

Smartphone‐based scans of palate models of newborns with cleft lip and palate: Outlooks for three‐dimensional image capturing and machine learning plate tool

AbstractObjectivesTo evaluate the performance of smartphone scanning applications (apps) in acquiring 3D meshes of cleft palate models. Secondarily, to validate a machine learning (ML) tool for computing automated presurgical plate (PSP).Materials and MethodsWe conducted a comparative analysis of two apps on 15 cleft palate models: five unilateral cleft lip and palate (UCLP), five bilateral cleft lip and palate (BCLP) and five isolated cleft palate (ICP). The scans were performed with and without a mirror to simulate intraoral acquisition. The 3D reconstructions were compared to control reconstructions acquired using a professional intraoral scanner using open‐source software.ResultsThirty 3D scans were acquired by each app, totalling 60 scans. The main findings were in the UCLP sample, where the KIRI scans without a mirror (0.22 ± 0.03 mm) had a good performance with a deviation from the ground truth comparable to the control group (0.14 ± 0.13 mm) (p = .653). Scaniverse scans with a mirror showed the lowest accuracy of all the samples. The ML tool was able to predict the landmarks and automatically generate the plates, except in ICP models. KIRI scans' plates showed better performance with (0.22 ± 0.06 mm) and without mirror (0.18 ± 0.05 mm), being comparable with controls (0.16 ± 0.08 mm) (p = .954 and p = .439, respectively).ConclusionsKIRI Engine performed better in scanning UCLP models without a mirror. The ML tool showed a high capability for morphology recognition and automated PSP generation.

A study of side shape analysis of free-form concrete panel using silicone mold and paraffin

This study analyzes the limitations of silicone molds used for free-form panel production and aims to address these issues by utilizing paraffin wax. Silicone molds are known for their reusability and ease of forming free-form shapes. However, the lack of a fixing method between the side and bottom molds makes them vulnerable to lateral pressure. Through FCP production experiments, 3D scans were conducted and shape errors were analyzed. The results showed that while the overall errors were uniform, errors exceeding 3 mm were observed at both ends of the curved sections. These errors are attributed to the installation of CNC equipment and the assembly process of the molds. Therefore, future research should focus on refining the corners and joints of the molds as well as validating complex curved shapes. This study is expected to serve as foundational data for research related to free-form molds.

Case Study and Literature Review on 3D Data Acquisition Technology for Small Artifacts

This study typification artifacts and data acquisition technologies and derived implications through a survey of domestic and oversea cases related to 3D data acquisition technology for small artifacts equal to or less than 15 cm. In terms of the type of relics, ceramics and earthenware(44.8%) and metals(27.6%) occupied the top ranks, while the proportion of wood and stone was relatively very low. In terms of technology, X-ray CT(61.2%), 3D scanning(15.5%), and photogrammetry(11.7%) showed high utilization rates. In order to ensure the sustainability and utilization of cultural heritage at a macro level, it is necessary to establish an accurate analysis of relics and a preservation strategy that complements the limitations of 3D data acquisition technology through the convergence of various technologies to increase the effectiveness of data acquisition, and to determine the external shape of the relics. An in-depth approach to future convergence technology is required to acquire high-precision 3D data, including information as well as internal structure and manufacturing techniques.

Field investigation of the feasibility of MICP for Mitigating Natural Rainfall-Induced erosion in gravelly clay slope

Rainfall-induced erosion on slopes is a prevalent natural process leading to soil loss. One promising application of microbially induced carbonate precipitation (MICP) is to mitigate rainfall-induced erosion. Conducting field tests is an essential step to verify and improve its performance. In the current work, field tests were conducted to assess the feasibility of using MICP to mitigate rainfall-induced erosion on a gravelly clay slope in Longyan, Fujian, China. A temporary laboratory was set up to cultivate bacteria, and a non-sterilizing method was employed to prepare large volumes of bacterial suspensions in a single batch. Slopes were treated by spraying solutions onto their surfaces. The amount of discharged soils and 3D surface scanning results were used for evaluating the erosion intensity of the slopes. The results demonstrated that the method could effectively mitigate the surface erosion caused by natural rainfall and prevent erosion-induced collapse. Notably, approximately one year after the treatment, the grass had started to grow on the heavily cemented slope, indicating that the MICP method is both effective and eco-friendly for soil stabilization method. However, further improvements are needed to enhance the uniformity and long-term durability of the MICP treatment.

Pottery from Motion – A Refined Approach to the Large-Scale Documentation of Pottery Using Structure from Motion

Abstract In recent years, interest in the usage of computer-based methods in archaeology, especially regarding field documentation, has grown significantly. In 2021, Göttlich et al. presented a new large-scale three-dimensional (3D) capture method for the documentation of pottery using structure from motion. This method, however, was only tested on a very small sample set and never truly conducted in a large-scale documentation surrounding. Consequently, we decided to test this workflow on a large-scale basis during three field campaigns (March 2022, November 2022, and March 2023) in Lebanon, documenting more than 4,000 sherds in total. In this article, I will present the results and observations of these campaigns, critically discuss the workflow involved (documentation and processing), and propose a refined workflow for this methodology. This article focuses solely on the relevant documentation and 3D processing.

MAFNet: a two-stage multiple attention fusion network for partial-to-partial point cloud registration

Abstract 3D point cloud registration is a critical technology in the fields of visual measurement and robot automation processing. In actual large-scale industrial production, the accuracy of point cloud registration directly affects the quality of automated welding processes. However, most existing methods are confronted with serious challenges such as the failure of partial-to-partial point cloud model registration when facing robot automatic processing guidance and error analysis work. Therefore, this paper proposes a novel two-stage network architecture for point cloud registration, which aims at robot pose adjustment and visual guidance in the field of automated welding by using 3D point cloud data. Specifically, we propose a neighborhood-based multi-head attention module in the coarse registration stage. The neighborhood information of each point can be aggregated through focusing on different weight coefficients of multi-head inputs. Then the spatial structure features which is used to establish the overlapping constraint of point clouds are obtained based on above neighborhood information. In the fine registration stage, we propose the similarity matching removal module based on multiple attention fusion features to explore deeper features from different aspects. By using deep fusion features to guide the similarity calculation, the interference of non-overlapping points is removed to achieve the finer registration. Eventually, we compare and analyze the proposed method with the SOTA ones through several error metrics and overlap estimation experiments based on the ModelNet40 dataset. The test results indicate that our method, relative to other mainstream techniques, achieves lower error rates and the most superior accuracy of 98.61% and recall of 98.37%. To demonstrate the generalization performance of proposed algorithm, extensive experiments on the Stanford 3D Scanning Repository, 7-Scenes and our own scanning dataset using partially overlapping point clouds individually under clean and noisy conditions show the validity and reliability of our proposed registration network.

Genome scan reveals several loci associated with torus palatinus.

Torus Palatinus (TP) is a common trait with an unclear aetiology. Although prior studies suggest a hereditary component, the genetic factors that influence TP risk remain unknown. The purpose of this study is to identify genetic variants associated with TP. We assessed the TP status of 829 individuals from various ancestral backgrounds using 3D palate scans. We then carried out a genome-wide association study (GWAS) to identify common variants associated with TP. We also performed gene-based tests across the exome to investigate the role of low-frequency coding variants. Our GWAS did not identify any genome-wide significant signals but identified suggestive associations including hits on chromosomes 2, 5 and 17 with p-values less than 5 × 10-6. Candidate genes at these suggestive loci have been implicated in normal-range craniofacial features, syndromes with facial and oral malformations, and bone density. We did not find evidence that low-frequency coding variants influence TP risk. In addition, we failed to replicate associations identified in prior genetic studies of TP. These findings suggest that multiple genes likely influence the development of TP. Independent replication will be required to confirm our suggestive associations.

3D Printed Metal Organic Framework Hydrogel for Dye Adsorption and Gas Sensing

AbstractMetal organic frameworks (MOFs) have tunable chemical structures, orderly pore structures, and modifiable surface functional groups making them a promising material for environmental remediation. However, their rigid powder morphology poses significant challenges for customizing MOF structures with adjustable mechanical properties. Here, we synthesis the stretchable UV‐curable MOF hydrogels through high‐resolution digital light processing 3D printing, and evaluated its adsorption effect on seven common dyesand.The results showed that it had selective adsorption effect on methylene blue (MB), and the adsorption effect increased with the increase of the initial concentration of MB: its adsorption capacity on 6 mgL−1, 12 mgL−1 and 24 mgL−1 MB solution reached 13.55 mgg−1, 26.31 mgg−1 and 50.70 mgg−1 respectively. Compared to powdered MOFs, the 3D‐printed MOF (Cu‐BTC) exhibited superior adsorption for dye and radioactive pollution, with methylene blue adsorption increasing from 8.93 mgg−1 to 25.05 mgg−1 and I2 adsorption from 141.56 mgg−1 to 792.65 mgg−1. Furthermore, the 3D‐printed MOF structure proved easily cleanable with dilute HCl and reusable over five times without degradation. In addition, our study highlighted the suitability of the 3D‐printed MOF for CO2‐sensing devices, demonstrating its broad applicability in environmental remediation and sensing technology.

Optimizing the pterional approach in medial sphenoid wing meningioma: a detailed morphometric study on anterior clinoidectomy and its effect on operability score

BackgroundMedial sphenoid wing meningiomas are best treated through pterional craniotomy, as pterional craniotomy provides wide and multidirectional exposure of the anterior and middle cranial fossa. Anterior clinoidectomy can increase the exposure potential. To delineate the role of anterior clinoidectomy (AC) in the standard pterional craniotomy approach through the evaluation of operability score measures (manoeuvrability arc, depth of surgical field, and surgical angle of attack). All patients with inner sphenoidal wing meningioma who underwent microsurgical excision between February 2022 and October 2023 were enrolled in the study. Preoperative and postoperative imaging studies (MR contrast studies and 3D thin-slice CT scans of the brain) were performed to determine the tumour size, extent, and pattern of optic canal involvement by comparing pre- and postoperative operability score parameters.ResultsTwenty-five patients met our inclusion criteria: 2 males (8%) and 23 females (92%). The mean age (SD) was 49.08 ± 6.42 years, with an age range of 39–60 years. The preoperative visual manifestations were as follows: eight patients (32%) had mild visual impairment, five patients (20%) had moderate visual impairment, six patients (24%) had severe visual impairment, and five patients (20%) had blindness. There was a significant positive correlation between the operability score and extent of resection (gross total resection was correlated with a higher operability score) (r = 0.301, n = 25, p = 0.005).ConclusionsA well-planned manoeuvrable arc allows neurosurgeons to perform surgery with precision, ultimately impacting surgical outcomes and the potential for complete tumour removal with minimal patient morbidity.

Development of an automated urban heritage monitoring tool: Between a techno-fix and fallacy

The preservation of urban heritage is one of the main challenges for contemporary society and an important task for governments. The administration of urban heritage preservation (UHP) requires effective methods, as well as sufficient material and human resources. The administrative practice of UHP is embedded in the relevant regulatory framework, which comprises legislative and normative acts at municipal, national, and international levels. The scale and range of heritage objects to be monitored, the complex statutory basis of the regulatory framework, and the traditionally low human and material resources of city administrations all contribute to the ineffectiveness of UHP practice in the UNESCO World Heritage Site of Vilnius.Advances in technologies such as 3D spatial scanning and AI-based image processing offer the promise of a technological fix to the ineffective administrative practice. In this paper, we present a grounded design study aimed at developing a technology prototype for an automated urban heritage risk monitoring tool. Originally conceived as a techno-fix to the inefficiency of administrative practice, the prototype development reveals tensions and stumbling blocks within digitalisation efforts. Using the analytical lens of the Trifecta model of IT-based regulation, the case study examines the interaction between technological and administrative domains in shaping technology design choices.Based on this case study, we critique the notion that IT is perceived as capable of providing “techno-fix” solutions to tasks requiring reflective human decision-making, especially when such solutions are expected to be effective without first redesigning the entire organisational system. The paper concludes with a discussion on the limits of automating administrative practices and identifies specific avenues for further research into the digitalisation of urban heritage preservation.

Applying 3D scanning to evaluate facial symmetry in Asian populations

BackgroundFacial symmetry enhances attractiveness, with various therapies available to improve it. However, trends in facial asymmetry remain unclear. This study evaluates differences between specific facial regions using 3D scanning to guide clinical treatment. MethodThe 3dMD face™ system (3dMD Ltd, USA) scanned 88 subjects' faces. Geomagic Wrap 2021 analyzed the left and right sides. Differences in eyebrow peaks, eyebrow tails, eye ends, and mouth corners were evaluated. ResultsMore subjects showed a drooping right side of the face in eyebrow peaks, eyebrow tails, eye ends, mouth corners, tubercula mentale, and mandibular margin positions. A higher proportion had deeper left nasolabial folds and marionette lines, while more had deeper right tear ducts and lateral chin depressions. More subjects exhibited a prominent right forehead and parotid masseter region, with a prominent left temporal and cheek region. Conclusion3D scanning effectively assesses facial asymmetry in clinical practice. Research indicates significant differences in asymmetry between facial regions. Evaluating these differences pre-treatment can guide the selection of therapeutic methods, improving facial asymmetry treatment. Level of Evidence3 (Diagnostic)

CLASSIFICATION OF DATA CAPTURING AND BUILDING SURVEYING TECHNIQUES IN THE CONTEXT OF SELECTING THE OPTIMAL METHOD OF CREATING 3D BIM AND HBIM MODELS OF EXISTING BUILDINGS

When creating a BIM information model of an existing building, a number of surveying techniques may be applied. The choice of particular technique depends largely on the budget of the investor commissioning the task and, on the specialist, commissioned to do it. Methods of conducting very accurate architectural survey and creating a digital 3D model are still fairly expensive due to the need of using specialist equipment. On the other hand, more common and affordable methods often lack the accuracy in the final model. This paper attempts to present a new classification of data capturing and building surveying techniques for creating 3D BIM models of existing buildings. The authors discuss optimal ways of applying particular methods and combining them so as to reduce the overall cost of the commissioned task and to achieve high accuracy of the final model at the same time. The analysis presented in this paper allows to introduce some order in the methods of creating BIM models of existing buildings by offering a new classification adjusted to standards currently used in architectural surveying.

Using a morph-based animation to visualise the face of Pharaoh Ramesses II ageing from middle to old age

Ramesses II was one of the most important Pharaohs to have presided over Egypt during the New Kingdom period. In 2023 researchers Wilkinson, Saleem, Liu and Roughley produced two digital 3D facial depictions showing Ramesses II at different ages: one around the age-at-death at 90 years old and the other, an age-regression at approximately 45 years old, based CT scans of his mummified remains, photographs, and historical information. The presence of two 3D facial depictions of one ancient individual at different ages affords an opportunity to show how Ramesses II might have looked during key moments of his lifetime and just prior to death. This paper describes the workflow adopted to add realistic textures to the facial depictions, and to use a morph-based animation to represent Ramesses II ageing from 45 to 90 years old.

Carapace Morphology Variations in Captive Tortoises: Insights from Three-Dimensional Analysis.

The carapace morphology of tortoises is a crucial characteristic used for species identification, with features such as shell shape, roughness, and color patterns varying among species. Understanding this morphological diversity is valuable not only for taxonomic classification but also for more specialized clinical approaches. This study investigated the morphological differences in the shells of Leopard tortoises (Stigmochelys pardalis), African spurred tortoises (Centrochelys sulcata), and Greek tortoises (spur-thighed tortoises; Testudo graeca) raised in captivity. Using 3D scanners, the carapaces were modeled, and a 3D geometric morphometric method was employed to analyze shape variations and dimensional features, with landmarks applied automatically. Among the species studied, African spurred tortoises had the largest carapace size. Principal component analysis (PCA) identified PC1 and PC3 as critical factors in distinguishing between species based on morphological characteristics. Positive PC1 values, associated with a shorter carapace height, indicated a flatter or more compact shell shape. A higher PC3 value corresponded to a raised shape at the back of the shell, while a lower PC3 value indicated a raised shape at the front. Specifically, Leopard tortoises exhibited a higher carapace shape than the other species, while African spurred tortoises had shorter carapaces. An allometric effect was observed in the carapaces, where smaller specimens tended to be proportionately higher-domed, whereas larger shells displayed a lower height in shape. These findings highlight the significance of shape variations in tortoise shells, which emerge during adaptation and have important implications for taxonomy and clinical practice. Such differences should be carefully considered in veterinary care and species identification.

The application of synthetic wollastonite in digital light processing 3D printing

In this study, 3D printable organic-inorganic resins were developed using glycerol dimethacrylate, which can be synthesised from glycerol obtained as a by-product of the biodiesel production process, and wollastonite synthesised from reagent-grade materials, the by-product of the aluminium fluoride manufacturing process, silica gel waste or natural rock. The developed recyclable waste-based material was proven to be compatible with the widely available desktop DLP 3D PICO2 39 printer. It allowed straightforward additive manufacturing of true 3D structures with sub-millimetre spatial definition using standard printing parameters. This opens the way for the production of inorganic objects from reusable industrial waste.

Digital Light Processing of Thermoresponsive Hydrogels from Polyproline-Based Star Polypeptides.

The first report of star poly(L-proline) crosslinkers is disclosed for digital light processing 3D printing of thermoresponsive hydrogels. Through chain end functionalization of star poly(L-proline)s with methacryloyl groups, access to high-resolution defined 3D hydrogel structures via digital light processing is achieved through photoinitiated free radical polymerization. Changing the poly(L-proline) molecular weight has a direct influence on both thermoresponsiveness and printability, while shape-morphing behavior can be induced thermally.

PCAlign: a general data augmentation framework for point clouds

With the advancement of 3D scanning technologies and deep learning theories, point cloud-based deep learning networks have gained considerable attention in the fields of 3D vision and computer graphics. Leveraging the rich geometric information present in 3D point clouds, these networks facilitate more accurate feature learning tasks. However, existing networks often suffer from generalization defects caused by variations in pose and inconsistent representations of training data. In this paper, we propose a novel data augmentation framework to overcome these limitations. Our approach utilizes principal component analysis (PCA) to generate four aligned copies of a point cloud. These copies are then input into a multi-channel structure, which is compatible with popular backbones of point cloud-based deep networks. Finally, the outputs of the multi-channel structure are merged to generate rotation-invariant feature learning results. Experimental evaluations demonstrate the efficacy of our framework, showcasing significant improvements in various existing point cloud-based deep learning methods. Notably, our method exhibits enhanced robustness in classification tasks, particularly when dealing with point clouds containing random pose variations and non-uniform densities. Project link: https://github.com/LAB123-tech/PCAlign.

Ergonomic glove pattern drafting method for hand assistive devices: considering 3D hand dimensions and finger mobility

Recently, interest has surged in glove-type assistive devices for relieving hand muscle stiffness caused by brain lesions. This study aims to develop an ergonomic method for drafting glove patterns intended for hand-assistive devices. To facilitate pattern development, we acquired three-dimensional (3D) scan data from the four hemiplegic patients while their hands were in a relaxed posture, which was subsequently transformed into two-dimensional (2D) data. Based on the 3D shape data, we analyzed the finger joint range of motion (ROM) and change ratio of skin surface length resulting from flexion and extension movements of the paralyzed hand. Incisions were strategically applied to regions displaying significant variations in these parameters. These flattened 2D patterns were then integrated into revised pattern blocks to enhance the shading data related to the 3D shape, resulting in the development of four glove patterns. We found that gloves prototyped using this innovative pattern-drafting method did not impede joint ROM when worn. Changes in clothing pressure inside the glove at the joints corresponded to the bending angles of the fingers, and the pressure did not exceed the discomfort threshold during hand flexion and extension movements. Importantly, participants provided positive subjective feedback concerning the comfort of the gloves. Our findings yield fundamental data for developing a foundational glove design for hand-assisted devices for patients with paralysis, achieved through the utilization of this novel ergonomic glove pattern-drafting method.

Stability of hot-finished and cold-formed steel hollow section columns: A comparative study

A comparative study into the buckling behaviour of hot-finished and cold-formed steel hollow section members subjected to axial compression is presented in this paper. The main differences between hot-finished and cold-formed hollow sections are initially discussed. An experimental programme conducted to investigate the local, global and local-global interactive buckling of hollow section columns is then described. Three S355 normalised hot-finished and three S355/S420 (dual certified) cold-formed profiles, covering circular, square and rectangular hollow sections (CHS, SHS and RHS respectively), were studied. The stress-strain characteristics of the examined materials were obtained through tensile coupon tests. 3D laser scanning was utilised to determine the distribution of geometric imperfections in selected SHS test specimens and a consistent approach to characterise different forms of geometric imperfections from the scan data is put forward. A stub column test was carried out on each cross-section to examine its local buckling behaviour, and a series of long column tests were performed on all test profiles. In total, 21 tensile coupon tests, six stub column tests and 40 long column tests were conducted in this programme. Finite element models were also developed, validated and used for parametric studies to generate supplementary numerical datasets. The obtained test and numerical data, along with the existing experimental results collected from the literature, were used to evaluate the accuracy and reliability of the Eurocode 3 (EC3) stability design provisions for hot-finished and cold-formed hollow section columns; aspects requiring improvements are highlighted to guide future studies.