Computer-aided Modeling Research Articles

Sealing mechanism study of laryngeal mask airways via 3D modelling and finite element analysis

Proper sealing of laryngeal mask airways (LMAs) is critical for airway management in clinical use. Understanding the sealing mechanism can significantly help front-line anaesthetists to reduce the incidence of adverse events. However, anaesthetists, who may not have the most substantial engineering backgrounds, lack intuitive ways to develop an understanding of the LMA sealing mechanism effectively. The paper aims to study the LMA-pharynx sealing mechanisms from the perspective of front-line anaesthetists. We use a computer-aided 3D modelling technique to visualise the LMA—pharynx interactions, which helps anaesthetists identify the critical areas of complications. Furthermore, we conduct a quantitative pressure distribution analysis of the LMA-pharynx contacting surface using the finite element analysis technique, which helps further understand the sealing mechanics in those areas. We present two cases studies based on one male volunteer, aged 50, inserted with a ProSeal LMA. In the first case, a relatively low cuff pressure (CP) was applied to simulate the clinical circumstances in which complications related to air leakage are most likely to happen; in the second case, we increase the CP to a relatively high value to simulate the scenarios with an increased risk of complications related to high mucosal pressure. The experiments suggest the follows: (1) Sore throat complications related to high mucosal pressure is most likely to occur in the hypopharynx with a high CP setting, particularly in the areas where the cricoid cartilage presses the mucosa. (2) The narrow hyoid bone super horn width likely causes LMA insertion difficulties. (3) Insufficient CP will significantly increase the risk of air leakage in the oropharynx. A complete sealing pressure line in the contacting surface will be formed with sufficient CP, thereby preventing the air leakage into the oral.

Three-Dimensional Computer-Aided Design Modeling and Printing for Accurate Toe-to-Hand Transplantation

To introduce toe-to-hand transplantation performed with the assistance of both bone and soft tissue modeling using 3-dimensional printing technology. From May 2015 to October 2018, 31 patients (group A, 24 thumbs and 7 fingers) were included. Computed tomography scans were acquired using a spiral computed tomography scanner, and the data were processed with software. Bone, skin, and nail models were created for tailoring the flap taken from the great toe. The impact of foot pathology in terms of pain, disability, and activity restriction was assessed using the Foot Function Index. For comparison, we included 35 patients (group B) who underwent toe-to-hand transplantation without the assistance of 3-dimensional computer-aided modeling. The mean duration of follow-up of groups A and B was 26 months (range, 24-31 months) and 27 months (range, 24-33 months), respectively. The mean Foot Function Index of groups A and B was 5 (range: 0-15) and 17 (range, 0-39), respectively. Three-dimensional computer-aided modeling and printing provide geometric accuracy in toe-to-hand transplantation. It also may reduce the donor foot morbidity by accurate flap designing and harvesting. Therapeutic IV.

Computer‐supported implant guided surgery using 3D planning software

Purpose: To evaluate the effectiveness of implant treatment using computer 3D modeling and surgical guided. Materials and Methods: The study included 148 patients who underwent prosthodontics rehabilitation using dental implants in 2017- 2022. 3D computer-aided modeling and surgical guide were used to plan the operation. To conduct a comparative analysis of the treatment results, two groups were formed: In group A (included 75 patients, fully guided surgery), in group B (included 73 patients). Results: In patients Group A intraoperative or immediate postoperative complications were noted (errors in the position, inclination), anatomical risk structures were invaded, after 3 years producing a survival rate of 96.2% In patients Group B, intraoperative complications were recorded; membrane perforation 4, errors in the position of the implants 16, the inclination of the implants 18, fenestration 12, after 3 years producing a survival rate of 97.6%. Mean marginal bone loss (MBL) patients in Group A were significantly higher than patients in group B (p < 0.05). In patients Group A the average surgical time from time of anesthesia to the placement of the healing abutment was 10.6 ± 2.9 min per implant, in patients Group B, the average surgical time was 16.4 ± 1.5 min per implant. Conclusion: The 3D modeling method and the controlled positioning of the implant allows surgical access with minimal trauma, reducing treatment time and complications

GENERATING NUMERICAL MULTIBODY MODEL OF TOOTHED BELT IN TECHNOLOGICAL MACHINES WITH SIEMENS NX

So far, in computer-aided modelling programs, there have not been implemented tools for the automatic generation of a dynamic model of an elastic belt transmission, created in the form of a multibody system. The publication presents reflections on this issue. There were developed scripts allowing one to automatically obtain the appropriate arrangement of links with respect to each other and to create the desired mechanical relations between or among them and other drive elements in the simulation. The programming bases of the proposed solutions were presented. Theoretical concepts were supported by application experiments in the Siemens NX environment. The method for the automatic generation of a multibody model of the toothed belt transmission, based on the geometric model of the latter, was developed. The work enabled the formulation of the conclusions on the development of modelling of the systems under consideration. The results of the research indicate high potential of the presented achievements. They constitute a basis for increasing the degree of computer technique aid for constructors or analysts.

Study of lifting platforms using three-dimensional computer-aided modeling

In the modern world, an aerial platform (auto-hydraulic lift) is an integral part of a rich model range of special crane equipment. The first primitive lift consisted of a lever, hinged on the base. A traction rope was placed on one side of the lever, and a counterweight on the other. With the help of his own physical strength, a person was able to rise to a small height using such a simple lifting mechanism. Currently, many types of lifts are used, which differ in height characteristics and the design of the lifting mechanism. Goal. The aim of this work is to study the kinematics of the moving elements of a hydraulic lift using a virtual model created on the basis of the Autodesk Inventor Professional software package. The model is based on an existing physical object. To study the kinematics of individual units and the installation as a whole, we use the method of modeling individual units and units of a machine, collecting them into a single mechanism with the task of all possible movements of structural elements in the Inventor package. Methodology. The assigned tasks can be solved by special design tools that are included in the software product, namely the environment for dynamic modeling, stress analysis. These tools are accessed while working in the "Assembly" environment, using the ribbon tabs "Design" and "Environments". The results of further research will bepresented in future publications.

Computer-Aided Modeling and Additive Manufacturing of Promising Protective Layer Materials for Catalytic Reactors

Computer-Aided Modeling and Additive Manufacturing of Promising Protective Layer Materials for Catalytic Reactors

Point of Care Virtual Surgical Planning and Three-Dimensional Printing for Feminizing Foreheadplasty.

Point of Care Virtual Surgical Planning and Three-Dimensional Printing for Feminizing Foreheadplasty.

Neutronics assessments of LHCD antenna system for CFETR

To maintain a long-duration plasma current and obtain steady-state operation for CFETR, a non-inductive Heating and Current Drive (H&CD) system is currently under study. Lower Hybrid Current Drive (LHCD) is an important auxiliary heating system, that has good current drive efficiency and improves plasma confinement by changing the current distribution.Neutronics calculation was conducted to study the nuclear performance and shielding effectiveness. This study was performed on a CFETR 22.5° model integrated with an upper-port LHCD antenna structure. The detailed 3D neutronics model was built using the computer-aided modeling platform cosVMPT, and particle transport was performed using MCNP5 with the nuclear data library FENDL-2.1. With the support of high performance variance reduction technique, “on-the-fly” GVR method, global neutron and photon flux distributions with reasonable relative error were obtained. The irradiation damage to components in the antenna system was assessed, including DPA, gas production and nuclear heat density. The total nuclear heat for the transmission structure was 1.192 MW, and the peak irradiation damage was located at the front end of the Passive-Active Multi-junction (PAM) launcher. Owing to the blanket opening for wave propagation, the induced nuclear responses for VV and TFC were analyzed, and the shielding design was initialized. The results showed that all the parameters were within the design limit after the shielding design. Because part of the blanket module was occupied by the antenna launcher, the TBR of CFETR was evaluated, and it decreased by only 0.22% for the whole fusion reactor.

Optical Detection of VOC Vapors Using Nb2O5 Bragg Stack in Transmission Mode

In this study, an emphasis is put on vapor-sensitive Bragg stacks as an important class of optical sensors. All-niobia Bragg stacks were deposited by spin-coating of sol-gel Nb2O5 thin films alternated with mesoporous layers after proper design through optimization of operating wavelength and number of layers in the stack. Mesoporous Nb2O5 films with different morphology and identical structure were obtained using organic templates (Pluronics PE6200 and PE6800) and subsequent annealing. Transmittance measurements were performed as a detection method that offers technological simplicity and accuracy. It was demonstrated that stacks including PE6200 templated films exhibit higher sensitivity than stacks templated with PE6800. It was assumed and verified by computer-aided modelling of experimental data that mesoporous films prepared with addition of PE6200, although less porous, were more stable compared to those templated with PE6800, and did not collapse during the thermal treatment of the stacks. Furthermore, the reproducibility of optical response was studied by sorption and desorption cycles of acetone vapors. The suitability of all-niobia Bragg stacks for optical sensing of VOCs was discussed.

Virtual Surgical Planning for Oncologic Mandibular and Maxillary Reconstruction.

Summary:Virtual surgical planning (VSP) with computer-aided design and computer-aided modeling (CAD/CAM) enables the opportunity to provide personalized medicine in complex head and neck reconstruction. This innovative technology allows ablative and reconstructive surgeons to virtually create and manipulate three-dimensional anatomic models to plan both the resection and reconstruction of complicated maxillofacial defects. Studies demonstrate improvements in preoperative planning, operative efficiency and accuracy, and postoperative outcomes. VSP facilitates immediate dental implantation in selected patients, which can improve the likelihood of achieving dental restoration. This article outlines strategies for technique optimization as well as the applications, advantages and disadvantages of VSP in complex oncologic head and neck reconstruction.

СИСТЕМА АВТОМАТИЗИРОВАННОГО ПРОЕКТИРОВАНИЯ И ПРОТОТИПИРОВАНИЯ УЧАСТКОВ СИНТЕЗА УГЛЕРОДНЫХ НАНОКЛАСТЕРНЫХ СТРУКТУР

The article focuses on using the integrated multi-component computer-aided design and control systems, which changes the product life cycle processes in the high-tech complex chemical and technological systems. In the integrated design of production facilities, special attention is paid to safety, productivity, reliability, ergonomics of the production line and the material and technical environment. The most effective in project management are flexible life cycle models that connect diverse specialists in a single information environment. The relevance of the task of developing and implementing problem-oriented heterogeneous computer-aided design and digital prototyping systems is justified. There is described a method for improving the efficiency of designing production facilities while minimizing the time required preparing a design solution, and the risks of design errors caused by the communication dissonance of diverse specialists. The architecture of the computer-aided design and digital prototyping system with a description of its basic components is presented. The creation of a digital model of the design object is described on the example of the reactor site and the material and technical base of the process of synthesis of carbon nanocluster structures that are in high demand in various industries. The conducted tests and the introduction of the resulting applied software solution into the educational process proved its efficiency in solving problems of integrated computer-aided design and digital modeling not only of objects of the carbon nanoindustry, but also for other industries with a similar material and technical base.

Impact of geological and technological factors on ore loss and dilution indicators based on muck modeling in open pit mine

The article presents a case-study of computer-aided modeling of muck in an open pit gold mine in order to evaluate ore losses and dilution under conditions of rock mass displacement induced by blasting with regard to different factors of geology and technology. The procedures of ore body outline displacement assessment and ore loss and dilution calculation are discussed in terms of a few blast blocks in an actually operating open pit mine. It is found that loss and dilution of ore can be reduced as a result of introduction of muck modeling and blasting pattern design and action control in mining. Rock mass displacements are nonlinear both horizontally and vertically, and depend on the blast block configuration, presence of a retaining wall, powder factor, as well as on the borehole structure and switching circuit.

Computer-aided drug design and pharmacophore modelling towards the discovery of novel anti-ebola agents

Computer-aided drug design and pharmacophore modelling towards the discovery of novel anti-ebola agents

A 3D printing Short Course: A Case Study for Applications in the Geoscience Teaching and Communication for Specialists and Non-experts

3D printing developed as a prototyping method in the early 1980s, yet it is considered as a 21st century technology for transforming digital models into tangible objects. 3D printing has recently become a critical tool in the geoscience research, education, and technical communication due to the expansion of the market for 3D printers and materials. 3D printing changes the perception of how we interact with our data and how we explain our science to non-experts, researchers, educators, and stakeholders. Hence, a one-day short course was designed and delivered to a group of professors, students, postdoctoral fellows, and technical staff to present the application of 3D printing in teaching and communication concepts in the geoscience. This case study was aimed at evaluating how a diverse group of participants with geoscience and engineering background and no prior experience with computer-aided modeling (CAD) or 3D printing could understand the principles of different 3D printing techniques and apply these methods in their respective disciplines. In addition, the course evaluation questionnaire allowed us to assess human perception of tangible and digital models and to demonstrate the effectiveness of 3D printing in data communication. The course involved five modules: 1) an introduction lecture on the 3D printing methods and materials; 2) an individual CAD modeling exercise; 3) a tour to 3D printing facilities with hands-on experience on model processing; 4) a tour to experimentation facilities where 3D-printed models were tested; and 5) group activities based on the examples of how to apply 3D printing in the current or future geoscience research and teaching. The participants had a unique opportunity to create a digital design at the beginning of the course using CAD software, analyze it and 3D print the final model at the end of the course. While this course helped the students understand how rendering algorithms could be used as a learning aid, educators gained experience in rapid preparation of visual aids for teaching, and researchers gained skills on the integration of the digital datasets with 3D-printed models to support societal and technical objectives.

Cnicin as an Anti-SARS-CoV-2: An Integrated In Silico and In Vitro Approach for the Rapid Identification of Potential COVID-19 Therapeutics.

Since the emergence of the SARS-CoV-2 pandemic in 2019, it has remained a significant global threat, especially with the newly evolved variants. Despite the presence of different COVID-19 vaccines, the discovery of proper antiviral therapeutics is an urgent necessity. Nature is considered as a historical trove for drug discovery, especially in global crises. During our efforts to discover potential anti-SARS CoV-2 natural therapeutics, screening our in-house natural products and plant crude extracts library led to the identification of C. benedictus extract as a promising candidate. To find out the main chemical constituents responsible for the extract’s antiviral activity, we utilized recently reported SARS CoV-2 structural information in comprehensive in silico investigations (e.g., ensemble docking and physics-based molecular modeling). As a result, we constructed protein–protein and protein–compound interaction networks that suggest cnicin as the most promising anti-SARS CoV-2 hit that might inhibit viral multi-targets. The subsequent in vitro validation confirmed that cnicin could impede the viral replication of SARS CoV-2 in a dose-dependent manner, with an IC50 value of 1.18 µg/mL. Furthermore, drug-like property calculations strongly recommended cnicin for further in vivo and clinical experiments. The present investigation highlighted natural products as crucial and readily available sources for developing antiviral therapeutics. Additionally, it revealed the key contributions of bioinformatics and computer-aided modeling tools in accelerating the discovery rate of potential therapeutics, particularly in emergency times like the current COVID-19 pandemic.

The checkerboard effect and mineral resource reporting of underground mineral resources

ABSTRACT The goal of a Mineral Resource statement is to estimate the in-situ tonnage and grade that might reasonably be expected to be extracted using the contemplated mining methods. Despite the transition by the mining industry to the use of computer-aided methods for preparing Mineral Resource estimates, the fundamental realities of complying with the CIM Definition Standards requirement of “Reasonable Prospects for Eventual Economic Extraction” (RPEEE) have not changed. Computer-aided block modeling can result in an irregular, patchwork of blocks above and below cutoff grade, termed the checkerboard effect. In such cases, for underground mining methods, strict application of a block cutoff grade does not consider the impact of any internal dilution blocks that may be present, while also potentially including blocks above cutoff grade that may not have sufficient spatial continuity. Considering the block dimensions relative to the selectivity of the potential underground mining method, this can result in material errors in Mineral Resource statements. The impact of the checkerboard effect varies from deposit to deposit. While several techniques are currently employed by Mineral Resource practitioners to ensure compliance with the RPEEE requirement of a Mineral Resource, practitioners are encouraged to develop additional methods and techniques that provide reasonable results.

Язык моделирования гетерогенных динамических систем LISMA_HDS

Heterogeneous dynamic systems (HDS) simultaneously describe processes of different physical nature. Systems of this kind are typical for numerous applications. HDSs are characterized by the following features. They are often multimode or hybrid systems. In general, their modes are defined as initial value problems (Cauchy problems) for implicit differential-algebraic systems of equations. Due to the presence of heterogeneous dynamic components or processes evolving in both time and space, the dimension of the complete system of equations may be pretty high. In some cases, the system of equations has an internal structure, for instance, the differential-algebraic system of equations approximating a partial differential equation by the method of lines. An original huge system of equations can then be algorithmically rewritten in a compact form. Moreover, heterogeneous hybrid dynamical systems can generate events of qualitatively different types. Therefore one has to use different numerical event detection algorithms. Nowadays, HDSs are modeled and simulated in computer environments. The modeling languages widely used by engineers do not allow them to fully specify all the properties of the systems of this class. For instance, they do not include event typing constructs. That is why a declarative general-purpose modeling language named LISMA_HDS has been developed for the computer-aided modeling and ISMA simulation environment. The language takes into account all of the characteristic features of HDSs. It includes constructs for plain or algorithmic declaration of model constants, initial value problems for explicit differential-algebraic systems of equations, and initial guesses for variables. It also allows researchers to define explicit time events, modes and transitions between them upon the occurrence of events of different types, to use macros and implement event control. LISMA_HDS is defined by a generative grammar in an extended Backus-Naur form and semantic constraints. It is proved that the grammar belongs to the LL(2) subclass of context-free grammars.

The Judgement for Development of Virtual Surgical Planning and Three-Dimensional Bio-Printing for Superior Reconstruction of Mandibular Defect by Fibular Graft on Head-Neck Cancer

Oncological resection followed by reconstruction with a free fibular graft is still considered to be the gold standard treatment for functional and prosthetic rehabilitation of oral cancer patients. But this tedious traditional process is challenging for surgeons, as they have to deal with associated curve anatomy, surrounding innervations, and maintenance of functional and aesthetical acceptability. Such manual and operator’s skill dependent surgery can commonly demand a longer treatment duration; leading to an increased risk for prolonging the period of ischemia with increased morbidity, which frequently ends with an uncertain, unsatisfactory outcome. Technological advancements in the 20th and 21st centuries present a revolutionary improvement in the field of reconstructive surgery. Virtual surgical planning (VSP) and threedimensional (3D) bio-printing incorporating computer-aided design and computer-aided modeling is a promising tech in modern head and neck reconstruction. This recent innovation is more polished regarding initiation of patient-customized models, pre-bent plates, and osteotomy guides which further increase surgical precision, improve operative efficiency, ensure proper wound healing, shorten operative time, reduce operative cost, and decrease morbidities. This review focuses on the virtual surgical planning and 3D bio-printing technologies to evaluate their efficiency of qualitative and quantitative outcomes of resection and reconstruction of mandible in head-neck cancer using fibular graft.

Design, Modeling and Performance Evaluation of Mobile Robot Based on Eccentric Paddle Mechanism

In order to improve climbing performance of the robot in complex environments, the wheeled-legged mechanism is gradually being widely used. In this paper, we use computer-aided modeling technology to design a 2-DOF ePaddle-based robot of high step-climbing capacity. Climbing strategies of the robot under the circle-wheeled (CW) mode and active-paddle-legged (APL) mode are carried out. We discuss determinants for success in climbing by establishing the climbing posture models. Simulation results processed with MATLAB tools reveal that paddle’s motion can significantly improve the climbing performance to avoid slipping. The experimental results verify the robot is capable of climbing over 300mm obstacle APL modes, which is 2.14 times the wheel radius.

A metabolomic approach to target antimalarial metabolites in the Artemisia annua fungal endophytes

Fungal endophytes are a major source of anti-infective agents and other medically relevant compounds. However, their classical blinded-chemical investigation is a challenging process due to their highly complex chemical makeup. Thus, utilizing cheminformatics tools such as metabolomics and computer-aided modelling is of great help deal with such complexity and select the most probable bioactive candidates. In the present study, we have explored the fungal endophytes associated with the well-known antimalarial medicinal plant Artemisia annua for their production of further antimalarial agents. Based on the preliminary antimalarial screening of these endophytes and using LC-HRMS-based metabolomics and multivariate analyses, we suggested different potentially active metabolites (compounds 1–8). Further in silico investigation using the neural-network-based prediction software PASS led to the selection of a group of quinone derivatives (compounds 1–5) as the most possible active hits. Subsequent in vitro validation revealed emodin (1) and physcion (2) to be potent antimalarial candidates with IC50 values of 0.9 and 1.9 µM, respectively. Our approach in the present investigation therefore can be applied as a preliminary evaluation step in the natural products drug discovery, which in turn can facilitate the isolation of selected metabolites notably the biologically active ones.