Advanced Computer-aided Design Research Articles

Patient-specific beta-tricalcium phosphate scaffold for customized alveolar ridge augmentation: a case report

BackgroundBeta-tricalcium phosphate (β-TCP) is a biocompatible ceramic material widely used in the field of oral regeneration. Due to its excellent biological and mechanical properties, it is increasingly utilized for alveolar ridge augmentation or guided bone regeneration (GBR). With recent advances in computer-aided design and manufacturing (CAD/CAM), β-TCP can now be used in the form of digitally designed patient-specific scaffolds for customized bone regeneration (CBR) of advanced defects in a two-stage implant therapy concept. In this case report following the CARE case report guidelines, we present a novel application of a patient-specific β-TCP scaffold in pre-implant mandibular alveolar ridge augmentation.Case presentationA 63-year-old female patient with significant horizontal bone loss in the posterior mandible was treated with a custom β-TCP scaffold in the context of a two-stage backward-planned implant therapy. Cone-beam computed tomography nine months after augmentation showed successful integration of the scaffold into the surrounding bone, allowing implant placement. Follow-up until two years after initial surgery showed excellent oral and peri-implant health.ConclusionsThis case highlights the potential of patient-specific β-TCP scaffolds for alveolar ridge augmentation and their advantage over traditional techniques, including avoidance of xeno-, allo-, and autografts. The results provide encouraging evidence for their use in clinical practice. Patient-specific β-TCP scaffolds may be a promising alternative for clinicians seeking to provide their patients with safe, predictable, and effective alveolar ridge augmentation results in customized bone regeneration procedures.

Customized three-dimensional printed ceramic bone grafts for osseous defects: a prospective randomized study

Ridge resorption can result in insufficient bone volume for implant surgery, necessitating bone substitutes to restore the resorption area. Recent advances in computer-aided design and manufacturing enable the use of alloplastic bone graft materials with customizable compositions or shapes. This randomized study evaluated the clinical effectiveness of a customized three-dimensional (3D) printed alloplastic bone material. Sixty patients requiring guided bone regeneration for implant installation following tooth extraction due to alveolar bone resorption were recruited at two institutions. The participants were randomly allocated to either a group that received 3D-printed patient-customized bone graft material or a group that received conventional block bone graft material. Implant installation with bone harvesting was performed approximately 5 months after bone grafting. Histological and radiological assessments of the harvested bone area were performed. The experimental group had a significantly higher percent bone volume and a smaller tissue surface than the control group. Bone volume, bone surface, bone surface/volume ratio, bone surface density (bone surface/total volume), and bone mineral density did not differ significantly between groups. Patient-customized bone graft materials offer convenience and reduce patient discomfort. The findings suggest 3D-printed patient-customized bone graft materials could be used as an alternative for simpler bone grafting procedures.

Natural product rhynchophylline prevents stress-induced hair graying by preserving melanocyte stem cells via the β2 adrenergic pathway suppression

Norepinephrine (NA), a stress hormone, can accelerate hair graying by binding to β2 adrenergic receptors (β2AR) on melanocyte stem cells (McSCs). From this, NA-β2AR axis could be a potential target for preventing the stress effect. However, identifying selective blockers for β2AR has been a key challenge. Therefore, in this study, advanced computer-aided drug design (CADD) techniques were harnessed to screen natural molecules, leading to the discovery of rhynchophylline as a promising compound. Rhynchophylline exhibited strong and stable binding within the active site of β2AR, as verified by molecular docking and dynamic simulation assays. When administered to cells, rhynchophylline effectively inhibited NA-β2AR signaling. This intervention resulted in a significant reduction of hair graying in a stress-induced mouse model, from 28.5% to 8.2%. To gain a deeper understanding of the underlying mechanisms, transcriptome sequencing was employed, which revealed that NA might disrupt melanogenesis by affecting intracellular calcium balance and promoting cell apoptosis. Importantly, rhynchophylline acted as a potent inhibitor of these downstream pathways. In conclusion, the study demonstrated that rhynchophylline has the potential to mitigate the negative impact of NA on melanogenesis by targeting β2AR, thus offering a promising solution for preventing stress-induced hair graying.Graphical

A numerical 3D fluid-structure interaction model for blood flow in a MRI-based atherosclerotic artery

Atherosclerosis, as a result of an inflammatory process, is the thickening and loss of elasticity of the walls of arteries that is associated with the formation of atherosclerotic plaques within the arterial intima, which present a double threat. A piece of vulnerable plaque can break off and be carried by the bloodstream until it gets stuck; and plaque that narrows an artery may lead to a thrombus that sticks to the blood vessel’s inner wall. The purpose of the present article is to compare effects across different atheromatous plaque material assumptions on hemodynamics and biomechanics within a partly patient-specific computational domain representing an atherosclerotic artery. A full scale 3D ESI numerical model is implemented and different material hyperelastic assumptions are considered for comparison purposes. The 3D realistic geometry is reconstructed from a medical image. This technique may be useful, specially with the recent advances in computer-aided design (CAD), medical imaging, and 3D printing technologies that have provided a rapid and cost efficient method to generate arterial stenotic biomodels, making in vitro studies a valuable and powerful tool. To understand our results, hemodynamic parameters and structural stress analysis were performed. The results are consistent with previous findings.

Current advances in computer-aided design of electrochemical sensors: An analytical review

Current advances in computer-aided design of electrochemical sensors: An analytical review

Design in Modern Information Systems by Applying Cloud Technologies

In this study, the general algorithm and technology of design in advanced computer-aided design (CAD) software of the CAD-in-the-Cloud type using an information model (IM) was discussed in detail. Applying design systems of this type increases productivity and quality of the development and enables group work on the project. The proposed information model consists of three main components – working with Autodesk Fusion 360 on a computer, working with cloud capabilities, and designers’ collaboration through the cloud. Nevertheless, some IM elements may be missing in a particular design, or there can be options for applying the proposed steps in the design process. Developing customized respiratory protective equipment (face masks) in Autodesk Fusion 360 CAD family was considered as an example of the suggested IM application. Modern design and producing technologies enable the creation of masks according to individual anatomical characteristics of the human face. In this paper, the protective mask was created by applying modern cloud computing technologies using information models. Information models were adapted to the process of protective mask design. The model of a human headform was developed using the 3D scanning method. After applying retopology tools, a basis of the mask frame was created on the surface of a 3D model of a head. Building a solid model and testing the mask fame configuration under mechanical stresses due to facial expression changing was carried out in Autodesk Fusion 360 CAD software. Finally, the cloud module of the generative design was applied to determine the filtering element configuration.

Black Bone MRI for Virtual Surgical Planning in Craniomaxillofacial Surgery.

Advances in computer-aided design and computer-aided manufacturing software have improved translational applications of virtual surgical planning (VSP) in craniomaxillofacial surgery, allowing for precise and accurate fabrication of cutting guides, stereolithographic models, and custom implants. High-resolution computed tomography (CT) imaging has traditionally been the gold standard imaging modality for VSP in craniomaxillofacial surgery but delivers ionizing radiation. Black bone magnetic resonance imaging (MRI) reduces the risks related to radiation exposure and has comparable functionality when compared with CT for VSP. Our group has studied the accuracy of utilizing black bone MRI in planning and executing several types of craniofacial surgeries, including cranial vault remodeling, maxillary advancement, and mandibular reconstruction using fibular bone. Here, we review clinical applications of black bone MRI pertaining to VSP and three-dimensional (3D)-printed guide creation for craniomaxillofacial surgery. Herein, we review the existing literature and our institutional experience comparing black bone MRI and CT in VSP-generated 3D model creation in cadaveric craniofacial surgeries including cranial vault reconstruction, maxillary advancement, and mandibular reconstruction with fibular free flap. Cadaver studies have demonstrated the ability to perform VSP and execute the procedure based on black bone MRI data and achieve outcomes similar to CT when performed for cranial vault reshaping, maxillary advancement, and mandibular reconstruction with free fibula. Limitations of the technology include increased time and costs of the MRI compared with CT and the possible need for general anesthesia or sedation in the pediatric population. VSP and 3D surgical guide creation can be performed using black bone MRI with comparable accuracy to high-resolution CT scans in a wide variety of craniofacial reconstructions. Successful segmentation, VSP, and 3D printing of accurate guides from black bone MRI demonstrate potential to change the preoperative planning standard of care. Black bone MRI also reduces exposure to ionizing radiation, which is of particular concern for the pediatric population or patients undergoing multiple scans.

The paradigm shift of mass customisation research

Industrial manufacturing is a core component of a nation’s economic wealth. It is driven by technology, and its paradigm has shifted from craft production to mass production to lean production to mass customisation (MC). We identify how emerging technologies offer a new way to shift MC research focusing on the scientific communities that have been driving MC research, changes in MC throughout the years, and the technological advances that influence future research trends of MC. We then identify MC paradigms. We analyse 1,947 MC papers from 1992 to 2019 and discover the research attention changes from the perspectives of the communities and themes using topic modelling. Our result indicates that MC was explained in terms of the business and marketing strategy (BMS) and the operations management (OM), in accordance with technological development. In BMS, MC topics moved from demand uncertainty to industry transformation. In OM, topics changed from assembly line for product differentiation to additive manufacturing. We discuss the future research agenda according to the technological advances in computer-aided design, additive manufacturing, machine learning, identification technologies, virtual reality, and human–robot collaboration. Not only researchers but practitioners and policymakers can utilise our approach to analyse and formulate MC strategies considering new technologies.

Necessary advances in computer-aided design to leverage on additive manufacturing design freedom

Advances in manufacturing technologies and computational engineering are key enablers for optimized designs necessary for product performance improvements. Amongst other manufacturing technologies, particularly Additive Manufacturing (AM) is pushing the envelope of feasible design complexity challenging design engineers as well as their Computer-Aided Design (CAD) tools. The research field of Design for Additive Manufacturing (DfAM) provides an exhaustive supply of specific engineering design knowledge and methodological approaches accordingly. To enable design engineers to put those approaches into practice, this research gathers and structures not yet addressed AM-related requirements on the state of the art CAD tools. Additionally, architectural CAD functions as well as features are being pointed out and envisioned design workflow adaptions introduced, necessary to enable engineers to holistically utilize AM design potentials with CAD systems of the mid-term future.

The multi-user computer-aided design collaborative learning framework

New developments to computer-aided design (CAD) software transform a once solitary modelling task into a collaborative one. The emerging multi-user CAD (MUCAD) systems allow virtual, real-time collaboration, with the potential to expand the learning outcomes and teaching methods of CAD. This paper proposes a MUCAD collaborative learning framework (MUCAD-CLF) to interpret backend analytic data from commercially available MUCAD software. The framework builds on several existing metrics from the literature and introduces newly developed methods to classify CAD actions collected from users’ analytic data. The framework contains two different classification approaches of user actions, categorizing actions by action type (e.g., creating, revising, viewing) and by design space (e.g., constructive, organizing), for comparative analysis. Next, the analytical framework is applied via a collaborative design challenge, corresponding to over 20,000 actions collected from 31 participants. Illustrative analyses utilizing the MUCAD-CLF are presented to demonstrate the resulting insight. Differences in CAD behaviour, indicating differences in learning, are observed between teams made up entirely of novices, entirely of experienced users, or a mix. In pairs of experts and novices, we see both a perceived high-satisfaction apprenticeship experience for the novices and preliminary evidence of an increase in expert design behaviours for the novices. The proposed framework is critical for MUCAD systems to make the most of the educational possibility of combining technical skill-building with team collaboration. Preliminary evidence collected in a fully-virtual design learning activity, and analyzed using the proposed MUCAD-CLF, shows that novice students gain advanced CAD design knowledge when collaborating with experienced teammates. With the user data captured by modern MUCAD software and the MUCAD-CLF presented herein, instructors and researchers can more efficiently assess and visualize students’ performance over the design learning process.

A Nonlinear Error Compensator for FDM 3D Printed Part Dimensions Using a Hybrid Algorithm Based on GMDH Neural Network

Following the advances in Computer-Aided Design (CAD) and Additive Manufacturing (AM), with regards to the numerous benefits of the Fused Deposition Modeling (FDM) as a popular AM process, resolving its weaknesses has become increasingly important. A serious problem of the FDM is the dimensional error or size difference between the CAD model and the actual 3D printed part.In this study, the approach is compensating the error regardless of its source. At First, all parameters affecting the dimensional accuracy of FDM are comprehensively identified. Then, multi-input–single-output (MISO) data is prepared by designing experiments using the Taguchi method and obtaining the results from 3D printed samples. Next, a GMDH neural network is applied, which uses a simple nonlinear regression formula in each neuron but can create very complex neuron combinations. So, it is possible to analyze small or even noisy data. Regulatory parameters of the Neural Net have been optimized to increase efficiency. The case study shows a decrease in the RSME for the Nominal CAD Model from 0.377 to 0.033, displaying the compensator's efficiency.

Penguatan kompetensi perancangan mesin melalui pelatihan computer-aided design bagi mahasiswa dan alumni teknik mesin (Strengthening of machine design skills through the computer-aided design training for mechanical engineering students and alumni)

The purpose of this service is to introduce and provide training on the use of Autodesk Inventor software to produce Computer-aided Design (CAD) based technical drawings according to the International Organization for Standardization (ISO). The method is carried out through theory, practice, and discussion, as well as completing machine design tasks independently and in groups. The training materials include working drawings, basic introduction to CAD, two-dimensional (2D) and three-dimensional (3D) drawing modeling, assembly, and presentation of 3D models. Evaluation of activities assessed refers to the readiness to complete the design task and the suitability of the drawings according to ISO standards. Based on the results of the basic level CAD training, there were achievements where participants had completed the technical drawing briefing material and completed the given design task. The design project task given requires mastery in terms of making 3D models from 2D sketch images, making layout drawings, making working drawings, and presenting them in a moving model presentation format. Successful completion of the task indicates that the participants understand and can operate the Autodesk Inventor software. In conclusion, this basic ability can be used as a provision for participants' self-development in the development and mastery of advanced CAD. This activity contributes based on the high interest in participating in training to the end and completing assignments and also has an indirect impact on the preparation of skilled CAD workers in the industry in Aceh.

Improving aircraft conceptual design through parametric CAD modellers – A case study for thermal analysis of aircraft systems

Aircraft manufacturers strive to improve their efficiency and effectiveness of the development processes. Increasing maturity and implementing more disciplinary analyses in the conceptual design are key enablers to reduce costly design iterations in later design stages. Therefore, the aircraft's conceptual design employs more and more multidisciplinary design analysis and optimization (MDAO) frameworks, which require automation of the involved disciplinary analysis. Recent aircraft conceptual MDAO frameworks integrate geometrical modellers, but these are generally limited to represent external aircraft geometry. Computer-Aided Design (CAD) software enables the generation of three-dimensional (3D) models that can provide geometrical parameters to most of the disciplines involved in aircraft conceptual design. Moreover, using an advanced CAD system early in conceptual design allows a seamless transition to more detailed design phases. For novel aircraft configuration and more electric, hybrid electric, and fully electric aircraft architectures, systems integration in the conceptual design is essential. To integrate aircraft systems and subsystems analyses within the MDAO frameworks, aircraft geometric or CAD modellers need to follow suit. This paper proposes a framework to describe CAD modellers' integration into MDAO environments for use in the conceptual design phase. This paper also formalizes the interactions between the disciplines and a CAD modeller within MDAO workflows and provides requirements for automated systems and subsystems analyses. Therefore, the presented work enables integrating novel disciplines, such as thermal, maintenance, safety, and electromagnetic compatibility (EMC) analyses, into the aircraft conceptual design phase. A case study covering the thermal analysis of an aircraft equipment bay demonstrates the effectiveness of the proposed MDAO framework.

High-Throughput Screening Platforms in the Discovery of Novel Drugs for Neurodegenerative Diseases.

Neurodegenerative diseases (NDDs) are incurable and debilitating conditions that result in progressive degeneration and/or death of nerve cells in the central nervous system (CNS). Identification of viable therapeutic targets and new treatments for CNS disorders and in particular, for NDDs is a major challenge in the field of drug discovery. These difficulties can be attributed to the diversity of cells involved, extreme complexity of the neural circuits, the limited capacity for tissue regeneration, and our incomplete understanding of the underlying pathological processes. Drug discovery is a complex and multidisciplinary process. The screening attrition rate in current drug discovery protocols mean that only one viable drug may arise from millions of screened compounds resulting in the need to improve discovery technologies and protocols to address the multiple causes of attrition. This has identified the need to screen larger libraries where the use of efficient high-throughput screening (HTS) becomes key in the discovery process. HTS can investigate hundreds of thousands of compounds per day. However, if fewer compounds could be screened without compromising the probability of success, the cost and time would be largely reduced. To that end, recent advances in computer-aided design, in silico libraries, and molecular docking software combined with the upscaling of cell-based platforms have evolved to improve screening efficiency with higher predictability and clinical applicability. We review, here, the increasing role of HTS in contemporary drug discovery processes, in particular for NDDs, and evaluate the criteria underlying its successful application. We also discuss the requirement of HTS for novel NDD therapies and examine the major current challenges in validating new drug targets and developing new treatments for NDDs.

Ribosome-targeting antibacterial agents: Advances, challenges, and opportunities.

Ribosomes, which synthesize proteins, are critical organelles for the survival and growth of bacteria. About 60% of approved antibiotics discovered so far combat pathogenic bacteria by targeting ribosomes. However, several issues, such as drug resistance and toxicity, have impeded the clinical use of ribosome-targeting antibiotics. Moreover, the complexity of the bacteria ribosome structure has retarded the discovery of new ribosome-targeting agents that are considered as the key to the drug-resistance and toxicity. To deal with these challenges, efforts such as medicinal chemistry optimization, combination treatment, and new drug delivery system have been developed. But not enough, the development of structural biology and new screening methods bring powerful tools, such as cryo-electron microscopy technology, advanced computer-aided drug design, and cell-free in vitro transcription/translation systems, for the discovery of novel ribosome-targeting antibiotics. Thus, in this paper, we overview the research on different aspects of bacterial ribosomes, especially focus on discussing the challenges in the discovery of ribosome-targeting antibacterial drugs and advances made to address issues such as drug-resistance and selectivity, which, we believe, provide perspectives for the discovery of novel antibiotics.

PEEK Biomaterial Use for Chairside CAD/CAM Dental Restorations: Bridging the Gap to Future

Background: Advanced computer-aided design and computer-aided manufacturing (CAD-CAM) technology led to the introduction of an increasing number of machinable materials suitable for dental prostheses. One of these materials is polyetheretherketone (PEEK), a high performance polymer recently used in dentistry with favorable physical, mechanical and chemical properties. Purpose: The aim of this study was to review the current published literature on the use of PEEK for the fabrication of dental prostheses with CAD-CAM techniques. Methods: Electronic database searches were performed using the terms “PEEK”, “CAD-CAM”, “dental”, “dentistry” to identify studies related to the use of PEEK for the fabrication of CAD-CAM prostheses. Results: A great number of in vitro studies are available in the current literature pointing out the noticeable properties of PEEK. The use of PEEK has been recommended for a wide range of CAD-CAM fabricated fixed and removable dental prostheses, occlusal splints, intra-radicular posts, implant abutments, customized healing abutments, space maintainers for pediatric dentistry, orthodontic appliances and provisional restorations. However, only a few clinical studies were identified. Conclusions: PEEK could be considered as a viable alternative for CAD-CAM dental appliances to well-established dental materials. Due to the scarcity of clinical data, clinical trials are needed to assess the longterm performance of PEEK prostheses.

The Materials Utilized in Cranial Reconstruction: Past, Current, and Future.

Cranioplasty (CP) is associated with high complication rates compared to other common neurosurgical procedures. Several graft materials are used for CP, which may contribute to the high complication rates, but data in the literature regarding the influence of graft material on post-CP outcomes are inconsistent making it difficult to determine if, when, and to what extent the graft material impacts the rate of perioperative complications. There is an increased demand to identify and develop superior graft materials. To review and compare the indications, risks, complications, and patient results associated with the use of different graft materials for cranial reconstructions. A search through EBSCOhost was conducted using the keywords "craniectomy" or "decompressive craniectomy," "cranioplasty," and "materials." The search was limited to literature published in the English language from 2005 until the present. Ultimately, 69 articles were included in this review. Due to the heterogeneity of the study populations, results, statistical analyses, and collecting methods, no statistical analyses could be performed. Several graft materials have been adapted for use in cranial reconstructions with inconsistent results making it unclear if or when one material may be indicated over others. Advances in computer-aided design have led to improved patient-specific implants, but the ideal graft material is still being sought after in ongoing research efforts. Reviewing materials currently available, as well as those in clinical trials, is important to identify the limitations associated with different implants and to guide future research.

Development of the Technology for Manufacturing a Combination EDM Electrode by Rapid Prototyping

Purpose of research is to develop a methodology that allows designing EDM electrodes applying advanced computer-aided design (CAD) systems by forming the tool’s working surface with geometry which is inverse equidistant to the geometry of a given workpiece taking into account the EDM gap, working translation or translation-rotational motion of EDM electrodes, the value of the layer of conductive coating based on the technological parameters of the processing procedure. It is also necessary to propose, implement and formulate technological guidelines for manufacturing EDM electrodes from dielectric materials by additive techniques with the subsequent formation of a conductive layer on them; the value of the layer should ensure the flow of working electrical processes in the EDM gap and the necessary tool life. This will make it possible to expand the scope of application of combination EDM electrodes as applied to combined processing techniques which are characterized by a wide variety of working surface shapes, which correspond to the geometry of the workpiece, which is not limited by the degree of curvature, has by far lower cost and high processability when creating a special tool for pilot and single manufacturing.Methods. When carrying out the work, theory of the classical laws of mechanical engineering technology, electrical processing techniques, the known laws of rapid prototyping and additive technologies were used.Results. The theoretical foundations and the technology for manufacturing combination EDM electrodes by rapid prototyping have been developed and a methodology for calculating and designing the working part of EDM electrodes has been proposed taking into account the geometric parameters of the machined surface and a variable EDM gap value.Conclusion. The mechanism of EDM electrode design by means of digital prototyping in modern CAD systems is justified taking into account the features of the workpiece geometry, EDM gap and metallization material.

ВИРТУАЛЬНЫЕ ТЕХНОЛОГИИ В СТОМАТОЛОГИИ

The article represents the information that in the age of digital dentistry, virtual treatment planning is becoming an increasingly important element of dental practice. With new technological advances in computer-aided design and computer-aided manufacturing (CAD/CAM) of dental restorations, predictable interdisciplinary treatment using a reverse planning approach appears to be beneficial and feasible. It is noted that thanks to achievements in medical imaging and computer programming, 2D axial images can be processed into other reformatted representations (sagittal and coronal) and three-dimensional (3D) virtual models representing the patient’s anatomy. It is shown that telemedicine occupies a special place among modern technologies in dentistry, which is used both for remote consultation and for the successful treatment of patients. Keywords: Virtual assistants , virtual nurses, voice technologies, artificial intelligence, virtual reality, 3D printing, telemedicine.

Towards an Artificial Intelligence Aided Design Approach: Application to Anime Faces with Generative Adversarial Networks

Abstract Ever since the inception of Machine Learning and Artificial Intelligence, the basic motto for most of research works has been to bring the machines at par with human intelligence. Designing new products and artifacts is one of the many fields where it is very difficult to enable computing machines replicate human creativity and innovativeness. Design processes in engineering fields as well as in arts follow methodical series of steps to create new products. Due to high demands of customized products and services, competitors tend to shorten the time-to-market periods, using advanced Computer-Aided Design programs. These programs play important roles to assist designers in digitizing blueprints and automating repetitive tasks. However, they fail to boost designer creativity by generating or suggesting new ideas or designs based on existing products or their variants. In order to boost creativity in the entertainment industry, we propose in this paper a new approach based on unsupervised learning techniques to create variants of a given artifact or product blueprints. Within the field of designing new cartoon characters, our proposed approach relies on Generative Adversarial Neural Networks [1] to create new anime or cartoon faces on their own without any human intervention. It learns features and characteristics from an image training dataset and combines them to create new features and thus builds a new image which is not present in the training dataset. This applied approach attempts to not only help artists and designers to have a preview of the possible new and unique avatars but also would prevent any copyright infringements.