Search Results (9)

Atrial leadless pacemakers (ALPMs) offer a minimally invasive solution for patients requiring atrial pacing, but current designs face significant challenges related to fixation stability, perforation risk, and retrievability. This study presents a novel self-expanding nitinol fixation system designed for deployment within the left atrial appendage (LAA), incorporating a flexible adapter for secure pacemaker engagement and retrieval. Finite-element simulations were conducted to assess gravitational displacement across different anatomical orientations, and fixture-expansion behavior was analyzed under various mesh configurations. The pacemaker drop analysis results demonstrated minimal displacement in neutral and upward-tilted LAA models, with increased instability observed in downward-tilted orientations. The fixture-expansion study showed that the 0.2 mm mesh design provided adequate mechanical strength and strain tolerance while maintaining a compact profile. This novel fixation system improves current ALPM limitations by providing stable, retrievable anchoring and favorable biomechanical performance. It may also serve as a dual-function platform for atrial pacing and stroke prevention when integrated with a left atrial appendage (LAA) occluder. These findings support further preclinical validation for clinical translation. Full article

Addressing the issues of easy deformation and difficult-to-control machining accuracy of thin-walled bearing rings during precision grinding due to clamping forces, existing research mainly employs methods such as elastic clamping, hydraulic control, pneumatic control, and vacuum adsorption to tackle the clamping problem. However, these methods still suffer from problems such as uneven clamping force, insufficient adaptability, and limited machining accuracy. In this paper, a novel fixture suitable for precision grinding of thin-walled bearing rings is designed. By analyzing the working principle of the fixture and considering the processing characteristics of thin-walled bearing rings, the fixture structure is designed and optimized to enhance its clamping stability and machining accuracy. Modal analysis and stress-displacement analysis are conducted to verify the stability and performance of the new fixture during the machining process. The research results show that the fixture can effectively reduce the deformation of thin-walled bearing rings, improve machining quality and efficiency, and provide a feasible solution for high-precision grinding of thin-walled bearing rings. Full article

Effective monitoring of road fixtures is essential for urban safety and functionality. However, traditional inspections are time-consuming, costly, and error prone, while current automated solutions struggle with high initial setup costs, limited flexibility preventing wide adaptation, and reliance on centralized processing that can delay response times. This study introduces an edge AI-based remote road fixture monitoring system which automatically and continuously updates the information of the road digital twin (DT). The main component is a small-sized edge device consisting of a camera, GPS, and IMU sensors designed to be installed in typical cars. The device captures images, detects the fixture, and estimates their location by employing deep learning and feature matching. This information is transmitted to a dedicated cloud server and represented on a user-friendly user interface. Experiments were conducted to test the system’s performance. The results showed that the device could successfully detect the fixture and estimate their global coordinates. Outputs were marked and shown on the road DT, proving the integrated and smooth operation of the whole system. The proposed Edge AI device demonstrated that it could significantly reduce the data size by 80–84% compared to traditional methods. With a satisfactory object detection accuracy of 65%, the system effectively identifies traffic poles, stop signs, and streetlights, integrating these findings into a digital twin for real-time monitoring. The proposed system improves road monitoring by cutting down on maintenance and emergency response times, increasing the ease of data use, and offering a foundation for an overview of urban road fixtures’ current state. However, the system’s reliance on the quality of data collected under varying environmental conditions suggests potential improvements for consistent performance across diverse scenarios. Full article

The unprecedented COVID-19 health crisis severely disrupted global sports in 2020, prompting lengthy suspensions followed by resumed competitions under abnormal behind-closed-doors conditions without fans. These disruptions necessitated tactical adaptations by coaches and teams, attempting to still achieve successful outcomes. This study investigates the pandemic’s impacts on performance metrics and indicators within Spanish professional soccer. Utilizing systematic notational analysis, 760 match cases from the 2019–2020 La Liga season were examined, comprising 27 matchdays from the pre-COVID context and 11 after resumption. Multivariate tests identified significant pre/post differences and interactions for various technical indicators including shots, cards, corners, and offside calls. The pandemic was associated with a reduction from 12 to just 5 identifiable playing styles, suggestive of increased conservatism featuring more passive play, limited attacking depth, and horizontal ball movement. Such tactical changes appear provoked by condensed fixture scheduling post-lockdown, the lack of supportive crowds, and compromised player fitness/recovery. By quantifying these COVID-precipitated changes, the analysis provides tangible evidence for coaches to make informed adjustments in training and preparation for functioning effectively in disrupted environments. The findings emphasize that versatility and flexibility will be vital to optimize performance during times of unprecedented uncertainty. Full article

The recent global pandemic has sped up architectural research in residential design aimed at rethinking housing layouts, services, and construction methods to accommodate the changing needs of the rapidly evolving contemporary society. New typological and technological design approaches are required to address, on the one hand, the adaptability of the plan as a result of higher flexibility and temporariness in familiar and working patterns, together with a downsizing of the layouts to ensure affordability and quality of life. On the other hand, the issues of sustainability and circular economy require specific attention to interpret the resilience of the building and the reuse/recycle of the fit-out systems. The paper aims at interpreting the notion of integration between fixtures and furnishing in housing design, based on a comprehensive literature review enriched with a case study analysis that shows design concepts and approaches rooted in theories and experiences of 20th-century architecture. Principles, potentials, and barriers to the development of integrated systems are highlighted and the possible implementation of industrialised production components, the potential for modularity, flexibility, and assembly are discussed. Full article

The soft robot has many degrees of freedom, strong environmental adaptability, and good human–computer interaction ability. As the end-effector of the soft robot, the soft gripper can grasp objects of different shapes without destructivity. Based on the theoretical analysis of the soft robot, the kinematics model of the flexible gripper and the theoretical model of the bending deformation of the air cavity were established. Accordingly, the relationship between the bending angle of the soft gripper and the air pressure was determined. Through the application of finite element software, the bending degree of the pneumatic network multi-cavity soft gripper was simulated, and the influence of structural parameters of soft actuator on bending deformation was determined. In addition, the 3D technology conducts the printing of soft gripper fixtures and molds, the injection molds the actuator, and the human–computer interaction interface controls the movement of the gripper. This paper proposes the control and monitoring of the soft gripper are realized through the electrical control module, the air circuit control module, and the sensor group module, and the size of the airflow velocity can be controlled by PWM DC speed regulation. The adaptability of the soft gripper in grasping objects was verified. The results shows that the software gripper possesses good flexibility and can better grasp objects of different shapes. Full article

The benefits of laser welding include higher production values, deeper penetration, higher welding speeds, adaptability, and higher power density. These characteristics make laser welding a superior process. Many industries are aware of the benefits of switching to lasers. For example, metal-joining is migrating to modern industrial laser technology due to improved yields, design flexibility, and energy efficiency. However, for an industrial process to be optimized for intelligent manufacturing in the era of Industry 4.0, it must be captured online using high-quality data. Laser welding of aluminum alloys presents a daunting challenge, mainly because aluminum is a less reliable material for welding than other commercial metals such as steel, primarily because of its physical properties: high thermal conductivity, high reflectivity, and low viscosity. The welding plates were fixed by a special welding fixture, to validate alignments and improve measurement accuracy, and a Computer-Aided Inspection (CAI) using 3D scanning was adopted. Certain literature has suggested real-time monitoring of intelligent techniques as a solution to the critical problems associated with aluminum laser welding. Real-time monitoring technologies are essential to improving welding efficiency and guaranteeing product quality. This paper critically reviews the research findings and advances for real-time monitoring of laser welding during the last 10 years. In the present work, a specific methodology originating from process monitoring using Computer-Aided Inspection in laser-welded blanks is reviewed as a candidate technology for a digital twin. Moreover, a novel digital model based on CAI and cloud manufacturing is proposed. Full article

The incomplete constraint induced by multipoint reconfigurable fixturing and the inherently weak rigidity of thin shell parts significantly hinder the stability of flexible fixturing systems. In particular, during the trimming operation, the number of effective locators may change with the progressive separation of the desired shape from that of the blank part, which easily produces the cliff effect (instantaneous dramatic reduction) of the system stiffness. As a result, the location layout becomes a main crux in reality. Regarding this issue, the author herein presents a digital twin-based decision-making methodology to generate reconfigurable fixturing schemes through integrating virtual and physical information. Considering the intrinsic features of the trimming process, such as the time-varying propagation of the system stiffness and the coupling effects of multiattribute process parameters, the hidden Markov model was introduced to cope with reconfigurable fixturing optimization. To achieve fast convergence and seek a feasible solution, local information (where low system rigidity occurs) was extracted and shared to guide the optimization process in a front-running simulation. To demonstrate the presented method, trimming experiments were performed on a large-size compliant workpiece held by a reconfigurable fixturing system that was developed independently by our research group. The experimental results indicate that the proposed method could adaptively iterate out the optimal locating schema and process control reference from the virtual fixturing and trimming simulation to guarantee the time-varying stability of the trimming process in the real world. Clearly, the digital twin-based reconfigurable fixturing planning approach generated a high possibility of building a context-specific, closed-loop decision-making paradigm and allowing the reconfigurable fixturing system to behave in a more adaptable and flexible manner. Full article

Thin floor machining is a challenging and demanding issue, due to vibrations that create poor surface quality. Several technologies have been developed to overcome this problem. Ad hoc fixtures for a given part geometry lead to meeting quality tolerances, but since they lack flexibility, they are expensive and not suitable for low manufacturing batches. On the contrary, flexible fixtures consisting of vacuum cups adaptable to a diversity of part geometries may not totally avoid vibrations, which greatly limits its use. The present study analyses the feasibility of thin floor milling in terms of vibration and roughness, in the cases where milling is conducted without back support, a usual situation when flexible fixtures are employed, so as to define the conditions for a stable milling in them and thus avoid the use of ad hoc fixtures. For that purpose, the change of modal parameters due to material removal and its influence on chatter appearance have been studied, by means of stability lobe diagrams and Fourier Transform analysis. Additionally, the relationship between surface roughness and chatter frequency, tooth passing frequency, and spindle frequency have been studied. Ploughing effect has also been observed during milling, and the factors that lead to the appearance of this undesirable effect have been analyzed, in order to avoid it. It has been proven that finish milling of thin floors without support in the axial direction of the mill can meet aeronautic tolerances and requirements, providing that proper cutting conditions and machining zones are selected. Full article