This paper aims to present a new robotic structure for Single Incision Laparoscopic Surgery (SILS). A short introduction into the SILS procedure is presented, followed by a definition of the ...requirements of a robotic structure for SILS based on the medical protocol for the surgical procedure. A simplified CAD model of a novel design for a modular parallel robotic structure is presented along with a detailing of its kinematic chains and the functionality of the robotic structure capable of achieving the motion particularities of a single-port surgical procedure, furthermore a conceptual control scheme based on the master-slave concept for this robotic structure is presented.
In a global approach to the design of mechanical systems, it is essential that all requirements are met. This is why it is important that all the disciplines that contribute to the realization of the ...product interact together. Model Based System Engineering (MBSE) is an interdisciplinary scientific approach, which is based on the use of standard representations, such as the systems modeling language SysML, to ensure integration, consistency and traceability between models generated during the systems development process. Computer-aided design (CAD), which has today become an essential step in modern industry, is also fundamental in the realization of the product. It covers the entire design process as well as that of the manufacture of all industrial products. However, a problem of collaboration between the system engineer who has a global view of the product and the designer who is the CAD specialist arises due to the lack of standard means of communication between the two disciplines. For this, our work aims to solve this problem of MBSE-CAD interoperability in order to finally be able to ensure the satisfaction of the product requirements. A methodology has been highlighted whose role is to collect data from the CAD model and translate them into data in SysML format. This methodology then plans to help the system engineer to build assembly graphs in SysML format from a 3D digital model. Based on a case study, that of a driving wheel of a forklift, the proposed methodology is illustrated with a validation example.
Impact of Torsion on Flexible Interconnects Altinozen, Ekrem; Vukovic, Ana; Sewell, Phillip
2022 IEEE International Conference on Flexible and Printable Sensors and Systems (FLEPS),
2022-July-10
Conference Proceeding
This paper reports on a computational model that is used to assess the reflection loss and transmission of flexible interconnects fabricated on a PI substrate and exposed to torsion deformation. ...Realistic material parameters that include dielectric and metallic losses typical of interconnects fabricated on the PI substrate are used in the model.
An exact analyze of the fracture type and selection of the ideal implant is essential for effective treatment of patients. The use of planning tool with virtual reality model and integrated FEA ...application can support the decision of implant's selection and therapeutic concept. With this tool, the rehabilitation can be developped in a virtual gait and the quality of the osteosynthesis process can be examined before the real operation is performed. For virtual reality applications the models of the bones from CT scans of human femur are built and then virtually fractured in the proximal end. The paper presents a series of CAD models combined with osteosynthesis devices and the principles of their integration in a virtual reality environment.
In the context of collaborative design, it is a challenge to effectively protect some IP(Intellectual Property) information while the model needs to be shared to another designer for co-design ...activities. In biology, genes determine the essential biological attributes of species and should be well kept. For collaborative design, the IP information of a CAD model is analogous to biological genes and can be therefore defined as Design Genes (DGs) to be protected during collaboration. Based on this concept, this paper presents a novel approach of DG based secure sharing of CAD models to support collaborative design. The approach consists of the following steps. Firstly, an innovative concept of DGs in a collaborative CAD model is defined used for representing protected knowledge in the model during collaboration. Secondly, a filter is introduced to identify the DGs of the model flexibly. An encryption algorithm is then described to encrypt the identified DGs of the model as encrypted DGs, while the other parts of the model are still geometrically valid and sharable to support collaborative design. Finally, case studies are used to validate the above steps. The innovation of the approach is the introduction of the innovative concept of DGs, development of related filter and encryption algorithm to ensure the security of critical information during collaborative design. The complexity of case studies can prove that the approach is applicable to realworld application scenarios.
The rapid development of scanning technologies has led to new challenges in Computer Aided Design (CAD) such as the reconstruction of the geometric model from a set of 3D points cloud. In fact, this ...model is the geometric support in various activities such as the analysis activity and the computer aided manufacturing activity. The CAD model is used in order to visualize scanned 3D objects by the approximation of the adequate shape using different mathematical equations. Thus, the most difficult stage in reconstructing a CAD model is 3D surface fitting. There are two sorts of 3D surfaces: simple geometric primitives (sphere, cylinder, cone, torus, etc.) and complex 3D surfaces (Bezier, B-Spline, NURBS, etc.). In this paper, we focus on the reconstruction of simple geometric primitives. These primitives can be found in a variety of settings, from home to industrial. The aim of this work is to select the appropriate algorithm that facilitates the approximation of geometric primitives given 3D point clouds. The following three strategies are proposed for a comparative study: the Levenberg Marquardt algorithm, the Spherical Harmonic method and the Trust-Region Reflective method. Based on the results of these algorithms, designers, manufacturers, and inspectors can choose the best method to reconstruct their final CAD model based on their specific needs.
Cancer, a diagnosis so dreaded and scary, that its fear alone can strike even the strongest of souls. The disease is often thought of as untreatable and unbearably painful, with usually, no cure ...available. Among all the cancers, breast cancer is the second most deadliest, especially among women. What decides the patients' fate is the early diagnosis of the cancer, facilitating subsequent clinical management. Mammography plays a vital role in the screening of breast cancers as it can detect any breast masses or calcifications early. However, the extremely dense breast tissues pose difficulty in the detection of cancer mass, thus, encouraging the use of machine learning (ML) techniques and artificial neural networks (ANN) to assist radiologists in faster cancer diagnosis. This paper explores the MIAS database, containing 332 digital mammograms from women, which were augmented and preprocessed, and fed into a custom and different pre-trained convolutional neural network (CNN) models, with the aim of differentiating healthy tissues from cancerous ones with high accuracy. Although the pre-trained CNN models produced splendid results, the custom CNN model came out on top, achieving test accuracy, AUC, precision, recall and \mathbf{F}_{1} scores of 0.9362, 0.9407, 0.9200, 0.8025 and 0.8572 respectively while having minimal to no overfitting. The paper, along with proposing a new custom CNN model for better breast cancer classification using raw mammograms, focuses on the significance of computer-aided detection (CAD) models overall in the early diagnosis of breast cancer. While a diagnosis of breast cancer may still leave patients dreaded, we believe our research can be a symbol of hope for all.
One of the remaining obstacles to a widespread introduction of industrial robots is their inability to deal with 3D objects in a bin that are not precisely positioned, i.e., the bin-picking problem. ...In this work we address the general bin-picking problem where a CAD model of the object to be picked is available beforehand. Structured light, in the form of Time Multiplexed Binary Stripes, is used together with a calibrated camera to obtain 3D data of the objects in the bin. The 3D data is then segmented into points of interest and for each a regional feature vector is extracted. The features are the Harmonic Shape Contexts. These are characterized by being rotational invariant and can in general model any free-form object. The Harmonic Shape Contexts are extracted from the 3D scene data and matched against similar features found in the CAD model. This allows for a pose estimation of the objects in the bin. Tests show the method to be capable of pose estimating partial-occluded objects, however, the method is also found to be sensitive to the resolution in the structured light system and to noise in the data.
Direct slicing can generate precise slice contours from original CAD models and obviates the error-detection and repairing process of STL files. At present, most direct slicing approaches are ...restricted to some CSG solids or particular CAD packages. In this paper, an approach for direct slicing of CAD models based on STEP for layered manufacturing is presented. The original CAD model is first transferred from CAD systems to the slicing system by neutral STEP files. Using OpenGL graphics libraries, the solid model is then displayed, and the user is prompted to specify the layer thickness. Finally, the CAD model is sliced directly, and the sliced model is exported by SSL (Stratasys Layer interface files) file format which can be sent to many kinds of layered manufacturing systems for direct fabrication. The approach of STEP-based direct slicing is more flexible and does not rely on any specific CAD system; in addition, the STEP files are much smaller than the STL files. Implementation details and results are also presented.
