3D Virtual Models Research Articles

Comparison of two-dimensional imaging to three-dimensional modeling of intrahepatic portosystemic shunts using computed tomography angiography.

Computed tomography angiography (CTA) is used for the diagnosis of intrahepatic portosystemic shunts (IHPSS). When planning for transcatheter intervention, caudal vena cava (CVC) measurements are typically obtained from two-dimensional (2D) imaging to aid in stent selection. We hypothesized that clinically applicable three-dimensional (3D) IHPSS models can be generated, and CVC measurements will not differ between 2D images and 3D models. Computed tomography angiography datasets from client-owned dogs with IHPSS at the University of Georgia Veterinary Teaching Hospital from 2016 to 2022 were analyzed. Materialise Mimics 25.0 and 3-matic 17.0 were used for 3D modeling. Caudal vena cava diameters were measured in 2D dorsal and transverse planes 20mm cranial and caudal from the shunt ostium and were compared with CVC diameters from 3D models. Length was measured in the 2D dorsal plane between midpoints of each diameter and compared to the 3D model length. Data are presented as mean (SD), and intraclass correlation coefficients were performed. Three-dimensional models were generated for 32 IHPSS (15 right-, 12 left-, and five central-divisional). Two-dimensional dorsal and transverse area-associated diameter measurements were 16.7mm (5.6) and 15.5mm (4.2) cranial; 14.9mm (4.2) and 14.3mm (3.7) caudal. Three-dimensional area-associated diameter measurements were 15.3mm (4.4) cranial and 14.0mm (3.6) caudal. The 2D length was 61.5mm (7.1) compared with 3D 59.9mm (7.2). Intraclass correlation coefficients comparing 2D and 3D diameters were all >0.80, indicating very good agreement, with good agreement (>0.60) for length. Clinically applicable 3D IHPSS models can be generated using engineering software. Measurements from 3D models are consistent with 2D planar imaging. Both 2D CTA and 3D virtual models can be utilized for preprocedural planning, depending on clinician preference.

Viewpoint Generation Using Geodesics and Associated Semi-Automated Coverage Path Planning of Panels for Inspection

The coverage of a surface using multiple viewpoints is a topic of great interest for robotic path planning in inspection applications. Two approaches for coverage path planning are broadly addressed in the literature—geometric methods and optimization methods. While the optimization methods may be the most flexible, they are frequently difficult to implement in practical applications due to their NP hard nature. We present here a geometric algorithm for the coverage path planning of panels used for aerospace applications using a generic camera model that can represent area inspection techniques like thermography and laser shearography. This algorithm relies on drawing a 2D grid on the 3D surface of the panel using geodesic lines on the surface. The coverage of the surface is performed by propagating geodesic lines from a starting point until the patch thus covered diverges too much from a flat surface, and after that, the coverage is continued from another point. The propagation of the geodesic lines is stopped when they begin to converge or diverge, and we define two criteria for the stoppage. We show that the proposed algorithm has good results for 3D virtual models and emphasize its speed, simplicity, and reliability for such applications.

Biomechanical Analysis of One-Piece Postand- Core: High-Performance Polymers vs Conventional Materials.

To evaluate the stress distribution along a premolar's root dentin, its post, and its post-luting agent when materials with different elastic moduli are used to fabricate one-piece post-and-cores in two different designs. Two 3D virtual models (for cylindrical and conical post designs) of a mandibular premolar restored with one-piece post-and-core restorations were obtained using a software. A total of eight post-and-core materials were tested: polyetheretherketone (PEEK), polyetherketoneketone (PEKK), glass fiber-reinforced polyetheretherketone (GFR-PEEK), carbon fiber-reinforced polyetheretherketone (CFR-PEEK), gold-palladium alloy (Au-Pd), titanium (Ti), zirconia (Zi), and chromium-nickel (Cr-Ni). Maximum principals stress (MPS) in the post, post-luting agent, and root dentin were determined. A load of 150 N was applied to the buccal cusp in the linguo-labial direction at an angle of 45 degrees oblique to the longitudinal axis of the crown. The highest MPS value in post structure was observed with Cr-Ni material for both post designs. Similarly, the highest MPS value in the post-luting agent was observed for Cr-Ni, the material with the highest elastic modulus. However, in the root dentin, the highest value was observed in PEEK, the material with the lowest elastic modulus. Post material and design influenced the stress concentration in the post, post-luting agent, and root dentin. The stress at the root dentin was slightly higher for polymeric materials. Cylindrical post design revealed lower stresses than conical post design at root dentin for all post-and-core materials tested.

Growth kinetics of benign neuroepithelial brain tumors in children with relapse

The problem of treating children with recurrent cerebral tumors cannot be solved without effective prediction of recurrent blastomatous growth. The main question will be, in addition to the possible risks of tumor recurrence, when should regrowth of the neoplasm be expected in time? In our opinion, one of the probable ways to solve this problem is to study the kinetics of tumor growth and create a mathematical model for it. The aim of the study was to analyze the kinetic features of the continued growth of benign neuroepithelial brain tumors in children after surgical treatment. The study included the results of an MRI of a 32 patients under the age of 17 years. All patients underwent brain tumor resection for the first time in the Department for Children Polenov Neurosurgical Institute (Almazov National Medical Research Centre). All patients had a relapse/continued tumor growth, as well as a benign nature of the neoplasm, which was confirmed pathomorphologically. To construct the kinetic curves, volumetric indicators of tumors obtained by virtual 3D-modeling were used. Depending on the histotype, the tumor growth rate was determined by the formula: v = (VT-VO)/T, and a graphical assessment of changes in the volume of the neoplasm was carried out – the construction of kinetic curves. Further, the most typical kinetic curves for each histological type of benign neuroepithelial tumors were identified.

Computer Vision and Machine-Learning Techniques for Automatic 3D Virtual Images Overlapping During Augmented Reality Guided Robotic Partial Nephrectomy.

The research's purpose is to develop a software that automatically integrates and overlay 3D virtual models of kidneys harboring renal masses into the Da Vinci robotic console, assisting surgeon during the intervention. Precision medicine, especially in the field of minimally-invasive partial nephrectomy, aims to use 3D virtual models as a guidance for augmented reality robotic procedures. However, the co-registration process of the virtual images over the real operative field is performed manually. In this prospective study, two strategies for the automatic overlapping of the model over the real kidney were explored: the computer vision technology, leveraging the super-enhancement of the kidney allowed by the intraoperative injection of Indocyanine green for superimposition and the convolutional neural network technology, based on the processing of live images from the endoscope, after a training of the software on frames from prerecorded videos of the same surgery. The work-team, comprising a bioengineer, a software-developer and a surgeon, collaborated to create hyper-accuracy 3D models for automatic 3D-AR-guided RAPN. For each patient, demographic and clinical data were collected. Two groups (group A for the first technology with 12 patients and group B for the second technology with 8 patients) were defined. They showed comparable preoperative and post-operative characteristics. Concerning the first technology the average co-registration time was 7 (3-11) seconds while in the case of the second technology 11 (6-13) seconds. No major intraoperative or postoperative complications were recorded. There were no differences in terms of functional outcomes between the groups at every time-point considered. The first technology allowed a successful anchoring of the 3D model to the kidney, despite minimal manual refinements. The second technology improved kidney automatic detection without relying on indocyanine injection, resulting in better organ boundaries identification during tests. Further studies are needed to confirm this preliminary evidence.

The Utilization of Virtual Reality Technology in the Scientific and Technological Protection and Cultural Inheritance of Clarke Porcelain--Taking Clarke Porcelain in the Collection of the City University of Macau as an Example

Abstract Virtual Reality (VR) technology heralds a transformative era for the safeguarding and disseminating cultural heritage. This paper examines its application through the lens of the Clark Porcelain collection at the City University of Macau, highlighting VR’s pivotal role in the scientific preservation and cultural transmission of these artifacts. By delving into the ornamental intricacies of Clark Porcelain, we evaluate VR’s effectiveness in protecting and showcasing these treasures. The study employs advanced techniques, including 3D virtual scene modeling, texture mapping, and collision detection, to replicate a museum setting, thus elevating the user’s interactive experience. An audience satisfaction survey indicates positive feedback, with relaxation and aesthetic satisfaction scores averaging 4.65 and 4.53, respectively. Moreover, ANOVA results reveal significant technological acceptance disparities across age groups. The Analysis further underscores VR’s substantial impact on cultural heritage promotion, noting the potential for better integration of Clark Porcelain with contemporary technologies. Virtual reality emerges as a formidable tool in the scientific conservation and cultural legacy of Clark Porcelain, offering fresh insights and technical backing for the modernization of traditional cultural heritage preservation.

Disruptive method for managing BIM design and construction using Kanban

Abstract Companies in the construction sector need effective information management. In particular, the transmission of information within a company is key to improving its management and competitiveness. Currently, many companies in the construction sector are making a great effort to implement the building information modelling (BIM) methodology. Such implementation requires collaborative work through the Cloud between the different agents in the construction process of any project. In fact, information management in BIM projects is related to the creation, storage, transfer and efficient application of information within a three-dimensional (3D) virtual model of the project. The size of the project also determines the optimal management approach. The main problems resulting from poor information management may be a lack of coordination between actors, loss of information or misinterpretation of information. This work has two stated objectives. The first objective is to carry out a literature review of the applications of BIM technology and the importance of managing knowledge according to International Organisation for Standardisation (ISO)- 19650. The second objective is to propose a disruptive method based on the Kanban tool to properly manage BIM information in the design and construction phases. This paper has practical implications for the improvement of BIM application for project managers.

Application of Skeletal Skinned Mesh Algorithm Based on 3D Virtual Human Model in Computer Animation Design

Application of Skeletal Skinned Mesh Algorithm Based on 3D Virtual Human Model in Computer Animation Design

Study on the timeliness of English teaching for college students under the background of multimedia

Abstract Starting with the actual multimedia English teaching, this paper analyzes the advantages of an intelligent learning environment as well as the application of virtual reality technology in English teaching. Comparing the traditional CAI courseware development with the courseware development based on virtual reality technology, it is proposed to use wavelet transform to decompose multimedia image resources, establish a static 3D virtual model library, transmit multimedia image files, and convert virtual reality-based network multimedia English teaching courseware. Propose a speech recognition algorithm based on DNN-HMM to help construct a multi-context virtual reality interaction mode. Examine the attitudes of students in different grades towards the use of virtual simulation technology in English teaching. Analyze the role of teaching timeliness in multimedia courseware and analyze the English classroom interaction in an interactive multimedia environment. In terms of student satisfaction, “your attitude towards the application of virtual simulation technology in English classes” is related to “the application of virtual simulation technology in English classes helps to open up new ways of English education, innovate new methods of education, and improve the carrier of education.” The correlation results are x 2 =32.051, p =0.000, showing 0.01 level of significance. It indicates that students believe that using virtual simulation technology in teaching can innovate English teaching and that using multimedia courseware can also enhance the timeliness of English teaching. The university’s English teaching mode using multimedia courseware and interactive multimedia environments can enhance English performance, and 80.37% of students believe it has timeliness in teaching.

Mixed reality for spine surgery: a step into the future with a human cadaveric accuracy study.

Current application of mixed reality as a navigation aid in the field of spinal navigation points to the potential of this technology in spine surgery. Crucial factors for acceptance include intuitive workflow, system stability, reliability, and accuracy of the method. The authors therefore aimed to investigate the accuracy of the system in visualization of anatomical structures using mixed reality in the example of pedicles of the thoracic spine in a human cadaveric study. Potential difficulties and limitations are discussed. CT scans of a human cadaveric spinal column specimen were performed. After segmentation and import into the advanced HoloLens 2 software, the vertebrae were exposed. The vertebral arches were preserved on one side for a landmark-based surface registration, whereas pedicles were exposed on the other side in order to measure and evaluate deviation of the overlay holographs with regard to the exact anatomical structure. Accuracy was measured and statistically evaluated. In this work it was demonstrated that the overlay of the virtual 3D model pedicles with the real anatomical structures with anatomical landmark registration was within an acceptable surgical accuracy with the mean value of 2.1 mm (maximum 3.8 mm, minimum 1.2 mm). The highest accuracy was registered at the medial and lateral pedicle wall, and the measurement results were best in the region of the middle thoracic spine. The accuracy analysis for mixed reality (i.e., between the virtual and real anatomical situation of the thoracic spine) showed a very good agreement when focus was on the pedicles. This work is thus a rare proof of the precision of segmentation to the potential surgical area. The results encourage researchers to open up mixed reality technology in its development and application for spinal navigation.

Enabling Circular Business Models through Design Methods and Tools

Despite the availability of multiple CBMs that merge economic sustainability with environmental considerations, each enterprise faces its own challenges in the transition from a linear to a circular economy. This work proposes an approach for organizations to determine which CBM aligns best with their practices, starting from available design tools, and being supported by the correlation matrix serves as allowing design tools to be integrated among core resources. With the support of the proposed approach, designers can extend their overview over multiple stages of a product’s lifecycle. The paper focuses on three design tools and identifies the lifecycle extension strategies they enable. The application provides an example of the implementation of the approach and involves three tools: the first quantitatively evaluates the environmental and economic sustainability of durable products; the second interrogates virtual 3D models and identifies recycling criticalities; the latter supports the research of new supply chain partners to avoid landfilling and incineration. The correlation matrix correlates the functionalities of the tools and ecofriendly models to commercialize goods and offer services, scheduling and prioritizing the introduction of innovative aspects and business models. Future work could introduce quantitative milestones for a more robust evaluation.

The Application of Computer Augmented Reality Technology to Landscape Design

Landscape design has a long history, from ancient royal gardens to modern urban parks, and its design concepts and techniques are constantly evolving. Nowadays, with the improvement of people's environmental requirements, landscape design is also constantly innovating. Although the landscape has made great progress, in actual operation, there are problems such as communication barriers with customers, difficulty in design implementation, and inability to preview the design effect in real time. Computer augmented reality technology has begun to play an important role in landscape design. Augmented Reality (AR) overlays the virtual 3D model into the real scene, previews the effect of design implementation in real time, carries out data analysis and optimization, and improves the design better to meet the needs of the public. In order to scientifically evaluate the effect of computer augmented reality technology in landscape design, this paper sets two main indicators: efficiency and quality. Efficiency is primarily concerned with the speed difference compared to traditional design methods. By means of comparative experiments, the time required to use augmented reality technology is calculated. Quality is mainly based on user feedback and expert review. Through users' actual experience of landscape design under augmented reality technology, their feedback is collected, and combined with professional review, the performance of augmented reality technology in design quality is comprehensively evaluated. This paper investigates the evaluation results of people in four landscapes (green plants, pavilions, ancient buildings, fountains). The survey results show that the fountain design quality is 80 points, the efficiency score is consistent with the pavilion, the feasibility score exceeds 80 points (82), and the user satisfaction is 5 points higher than the pavilion design.

A Database-Driven Excavation of a Waterlogged Neolithic Settlement: The Case of Küssnacht-Immensee Dorfplatz (Switzerland)

ABSTRACT A settlement excavation of a site with waterlogged conditions was conducted in Küssnacht-Immensee (Lake Zug, Canton Schwyz, Switzerland). The documentation abandoned the idea of drawings and verbal description. Instead, based on prior research on the deposition mechanisms of this type of settlements, clearly specified sediment features were documented in a semi-quantitative fashion in a database, allowing for generic 3D modelling of the deposits and efficient 2D GIS-based evaluation of the excavation results. We present the database design and some example results that characterise the depositional processes. Strain-free profile photographs were mounted in the same 3D virtual model. We discuss different procedures and their pros and cons.

3D Specimen Scanning and Mapping in Musculoskeletal Oncology: A Feasibility Study.

Surgical resection is the primary treatment for bone and soft tissue tumors. Negative margin status is a key factor in prognosis. Given the three-dimensional (3D) anatomic complexity of musculoskeletal tumor specimens, communication of margin results between surgeons and pathologists is challenging. We sought to perform ex vivo 3D scanning of musculoskeletal oncology specimens to enhance communication between surgeons and pathologists. Immediately after surgical resection, 3D scanning of the fresh specimen is performed prior to frozen section analysis. During pathologic grossing, whether frozen or permanent, margin sampling sites are annotated on the virtual 3D model using computer-aided design (CAD) software. 3D scanning was performed in seven cases (six soft tissue, one bone), with specimen mapping on six cases. Intraoperative 3D scanning and mapping was performed in one case in which the location of margin sampling was shown virtually in real-time to the operating surgeon to help achieve a negative margin. In six cases, the 3D model was used to communicate final permanent section analysis. Soft tissue, cartilage, and bone (including lytic lesions within bone) showed acceptable resolution. Virtual 3D scanning and specimen mapping is feasible and may allow for enhanced documentation and communication. This protocol provides useful information for anatomically complex musculoskeletal tumor specimens. Future studies will evaluate the effect of the protocol on positive margin rates, likelihood that a re-resection contains additional malignancy, and exploration of targeted adjuvant radiation protocols using a patient-specific 3D specimen map.

Caries Lesion Assessment Using 3D Virtual Models by Examiners with Different Degrees of Clinical Experience.

Background and Objectives: Dental caries is a preventable, reversible disease in its early stages. This study evaluated the intra-rater agreement of International Caries Assessment and Detection System (ICDAS) scores with Medit i500® and Omnicam® scanners versus traditional clinical examinations and the inter-rater agreement using the Omnicam® among senior dentists and dental students and between these two groups. Materials and Methods: A total of 24 patients aged between 21 and 34 years, randomly selected from dental students and interns, underwent four examinations (three intraoral scans and one clinical examination), and the corresponding ICDAS scores were recorded by a randomly selected rater out of the 31 available examiners. The examination team consisted of dental students, dentists with less than 3 years, and dentists with more than 5 years of clinical experience. The following inter- and intra-rater agreement tests for the ordinal data were chosen: Fleiss' kappa coefficient, Cohen's weighted kappa, and inter-class correlations. Results: For all examination techniques, there was statistically significant agreement for the experienced raters (p < 0.05). The highest positive interclass correlation was obtained for inter-rater agreement tests of 288 observations recorded by senior dentists: ICC = 0.969 (95% CI 0.949-0.981). Conclusions: Intra-rater reliability was excellent for Omnicam compared to clinical exams conducted by senior dentists but moderate for Medit i500. Although inter-rater agreement using Omnicam was poor between students and between senior dentists and students, it was excellent among senior dentists.

A comprehensive review of haptic feedback in minimally invasive robotic liver surgery: Advancements and challenges

AbstractBackgroundLiver medical procedures are considered one of the most challenging because of the liver's complex geometry, heterogeneity, mechanical properties, and movement due to respiration. Haptic features integrated into needle insertion systems and other medical devices could support physicians but are uncommon. Additional training time and safety concerns make it difficult to implement in robot‐assisted surgery. The main challenges of any haptic device in a teleoperated system are the stability and transparency levels required to develop a safe and efficient system that suits the physician's needs.PurposeThe objective of the review article is to investigate whether haptic‐based teleoperation potentially improves the efficiency and safety of liver needle insertion procedures compared with insertion without haptic feedback. In addition, it looks into haptic technology that can be integrated into simulators to train novice physicians in liver procedures.MethodsThis review presents the physician's needs during liver interventions and the consequent requirements of haptic features to help the physician. This paper provides an overview of the different aspects of a teleoperation system in various applications, especially in the medical field. It finally presents the state‐of‐the‐art haptic technology in robot‐assisted procedures for the liver. This includes 3D virtual models of the liver and force measurement techniques used in haptic rendering to estimate the real‐time position of the surgical instrument relative to the liver.ResultsHaptic feedback technology can be used to navigate the surgical tool through the desired trajectory to reach the target accurately and avoid critical regions. It also helps distinguish between various textures of liver tissue.ConclusionHaptic feedback can complement the physician's experience to compensate for the lack of real‐time imaging during Computed Tomography guided (CT‐guided) liver procedures. Consequently, it helps the physician mitigate the destruction of healthy tissues and takes less time to reach the target.

Simultaneous reconstruction after resection of meningiomas of the cranial base that invade the orbit assisted by virtual planning and 3D models. A new proposal

Simultaneous reconstruction after resection of meningiomas of the cranial base that invade the orbit assisted by virtual planning and 3D models. A new proposal

Optimising Amber Processing Using 3D Scanning: New Perspectives in Cultural Heritage

This article aims to present the practical and functional application of advanced 3D scanning technologies in the process of designing products made of amber. The processing of amber is complex and expensive because mass or serial production is not possible. Moreover, processing is challenging because each product is treated as unique and requires individual handling. The optimisation process is illustrated using the example of amber blocks that were scanned to obtain virtual 3D models. The scope of this work includes the characterisation of three-dimensional jewellery design processes, along with a description of a wide range of methods and functions used in computer-aided jewellery design. The use of computer-aided design software for developing virtual models of decorative products used in goldsmithing is described in this paper. The obtained sets of models underwent engineering analysis using Boolean algebra and data science calculations. In this way, a design methodology was developed regarding the selection of input material as the unprocessed stone for jewellery modelling. The developed method allows for the minimisation of material waste, which is associated with reducing costs in the processing of amber. This article also describes the differences between previous traditional methods and the authors’ proprietary method. The proposed methodology can be implemented in jewellery workshops specialising in the processing of materials.

Computer aided multiplanar osteotomy using patient specific instrumentation to treat cubitus varus in children

Cubitus varus deformity is a common complication of supra-condylar fractures in children.Anatomic correction is the key to obtaining good functional results and avoiding later symptomatic degradation. Different techniques have been described, mainly lateral closing wedge osteotomy. A medial opening wedge osteotomy seems more intuitive, allowing an anatomic reduction, but it is technically challenging.Two-plane radiographs are too simplistic to appreciate the 3D deformity. With medical imaging and image processing advances, three-dimensional (3D) virtual models of a patient’s anatomy can be generated. Rapid 3D printing has allowed virtual simulations of surgical corrections to be transferred to real-world applications in the operating room, allowing more precise and accurate surgery with better 3D corrections.3D computer modeling with the development of customized drilling and cutting guides allows complex medial opening wedge osteotomy for correction of cubitus varus deformity in immature children with best-fit plate synthesis.Level of evidence: IV

An auditory virtual reality of meeting room acoustics using wave-based acoustic simulations: A content for intuitive understanding of room-acoustics control effect by sound absorbers

Recently, wave-based room acoustic simulation technologies are becoming a realistic option as a small-room acoustics design tool and a virtual indoor sound environment creation tool for research and education. The present paper shows an auditory VR meeting room content, which makes us easily understand how sound absorbers play an essential role in creating a better acoustic environment. Unity creates the 3D virtual reality model, and a binaural room-acoustic auralization is realized by a hybrid technique combined with Ambisonics and the head-related transfer function using RIRs computed by a high-speed parallel wave-based room acoustics solver. The VR meeting room is constructed under various acoustic treatments with sound absorber modeling by wave-based material models.