Download or read book Computational Biomechanics for Medicine written by Adam Wittek and published by Springer Science & Business Media. This book was released on 2014-07-08 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the greatest challenges for mechanical engineers is to extend the success of computational mechanics to fields outside traditional engineering, in particular to biology, biomedical sciences, and medicine. This book is an opportunity for computational biomechanics specialists to present and exchange opinions on the opportunities of applying their techniques to computer-integrated medicine. Computational Biomechanics for Medicine: Models, Algorithms and Implementation collects the papers from the Seventh Computational Biomechanics for Medicine Workshop held in Nice in conjunction with the Medical Image Computing and Computer Assisted Intervention conference. The topics covered include: medical image analysis, image-guided surgery, surgical simulation, surgical intervention planning, disease prognosis and diagnostics, injury mechanism analysis, implant and prostheses design, and medical robotics.

Download or read book Computational Biomechanics for Medicine written by Martyn P. Nash and published by Springer. This book was released on 2019-08-13 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains contributions from computational biomechanics specialists who present and exchange opinions on the opportunities for applying their techniques to computer-integrated medicine, including computer-aided surgery and diagnostic systems. Computational Biomechanics for Medicine collects peer-reviewed chapters from the annual Computational Biomechanics for Medicine Workshop, in conjunction with the Medical Image Computing and Computer Assisted Intervention [MICCAI] Society conference. The works are dedicated to research in the field of methods and applications of computational biomechanics to medical image analysis, image-guided surgery, surgical simulation, surgical intervention planning, disease diagnosis and prognosis, analysis of injury mechanisms, implant and prosthesis design, artificial organ design, and medical robotics. These chapters will appeal to a wide range of researchers and students within the fields of engineering and medicine, as well as those working in computational science.

Download or read book Computational Biomechanics for Medicine written by Karol Miller and published by Springer Nature. This book was released on 2021-07-17 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational Biomechanics for Medicine: Solid and fluid mechanics for the benefit of patients contributions and papers from the MICCAI Computational Biomechanics for Medicine Workshop help in conjunction with Medical Image Computing and Computer Assisted Intervention conference (MICCAI 2020) in Lima, Peru. The content is dedicated to research in the field of methods and applications of computational biomechanics to medical image analysis, image-guided surgery, surgical simulation, surgical intervention planning, disease prognosis and diagnostics, analysis of injury mechanisms, implant and prostheses design, as well as artificial organ design and medical robotics. This book appeals to researchers, students and professionals in the field.

Download or read book Biomechanics of the Brain written by Karol Miller and published by Springer. This book was released on 2019-08-08 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new edition presents an authoritative account of the current state of brain biomechanics research for engineers, scientists and medical professionals. Since the first edition in 2011, this topic has unquestionably entered into the mainstream of biomechanical research. The book brings together leading scientists in the diverse fields of anatomy, neuroimaging, image-guided neurosurgery, brain injury, solid and fluid mechanics, mathematical modelling and computer simulation to paint an inclusive picture of the rapidly evolving field. Covering topics from brain anatomy and imaging to sophisticated methods of modeling brain injury and neurosurgery (including the most recent applications of biomechanics to treat epilepsy), to the cutting edge methods in analyzing cerebrospinal fluid and blood flow, this book is the comprehensive reference in the field. Experienced researchers as well as students will find this book useful.

Download or read book Manufacturing In The Era Of 4th Industrial Revolution A World Scientific Reference In 3 Volumes written by and published by World Scientific. This book was released on 2021-01-13 with total page 1000 pages. Available in PDF, EPUB and Kindle. Book excerpt: The era of the fourth industrial revolution has fundamentally transformed the manufacturing landscape. Products are getting increasingly complex and customers expect a higher level of customization and quality. Manufacturing in the Era of 4th Industrial Revolution explores three technologies that are the building blocks of the next-generation advanced manufacturing.The first technology covered in Volume 1 is Additive Manufacturing (AM). AM has emerged as a very popular manufacturing process. The most common form of AM is referred to as 'three-dimensional (3D) printing'. Overall, the revolution of additive manufacturing has led to many opportunities in fabricating complex, customized, and novel products. As the number of printable materials increases and AM processes evolve, manufacturing capabilities for future engineering systems will expand rapidly, resulting in a completely new paradigm for solving a myriad of global problems.The second technology is industrial robots, which is covered in Volume 2 on Robotics. Traditionally, industrial robots have been used on mass production lines, where the same manufacturing operation is repeated many times. Recent advances in human-safe industrial robots present an opportunity for creating hybrid work cells, where humans and robots can collaborate in close physical proximities. This Cobots, or collaborative robots, has opened up to opportunity for humans and robots to work more closely together. Recent advances in artificial intelligence are striving to make industrial robots more agile, with the ability to adapt to changing environments and tasks. Additionally, recent advances in force and tactile sensing enable robots to be used in complex manufacturing tasks. These new capabilities are expanding the role of robotics in manufacturing operations and leading to significant growth in the industrial robotics area.The third technology covered in Volume 3 is augmented and virtual reality. Augmented and virtual reality (AR/VR) technologies are being leveraged by the manufacturing community to improve operations in a wide variety of ways. Traditional applications have included operator training and design visualization, with more recent applications including interactive design and manufacturing planning, human and robot interactions, ergonomic analysis, information and knowledge capture, and manufacturing simulation. The advent of low-cost solutions in these areas is accepted to accelerate the rate of adoption of these technologies in the manufacturing and related sectors.Consisting of chapters by leading experts in the world, Manufacturing in the Era of 4th Industrial Revolution provides a reference set for supporting graduate programs in the advanced manufacturing area.

Download or read book Surgery Simulation and Soft Tissue Modeling written by Nicholas Ayache and published by Springer Science & Business Media. This book was released on 2003-06-04 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the International Symposium on Surgery Simulation and Soft Tissue Modeling, IS4TM 2003, held in Juan-Les-Pins, France in June 2003. The 33 revised full papers presented together with 3 invited papers were carefully reviewed and selected from 45 submissions. The papers are organized in topical sections on soft tissue models, haptic rendering, cardiac modeling, and patient specific simulators.

Download or read book Human Centered Technology for a Better Tomorrow written by Mohd Hasnun Arif Hassan and published by Springer Nature. This book was released on 2021-10-01 with total page 742 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book acts as a compilation of papers presented in the Human Engineering Symposium (HUMENS 2021). The symposium theme, “Human-centered Technology for A Better Tomorrow,” covers the following research topics: ergonomics, biomechanics, sports technology, medical device and instrumentation, artificial intelligence / machine learning, industrial design, rehabilitation, additive manufacturing, modelling and bio-simulation, and signal processing. Fifty-nine articles published in this book are divided into four parts, namely Part 1—Artificial Intelligence and Biosimulation, Part 2—Biomechanics, Safety and Sports, Part 3—Design and Instrumentation, and Part 4—Ergonomics.

Download or read book Encyclopedia Of Medical Robotics The In 4 Volumes written by and published by World Scientific. This book was released on 2018-08-28 with total page 1555 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Encyclopedia of Medical Robotics combines contributions in four distinct areas of Medical robotics, namely: Minimally Invasive Surgical Robotics, Micro and Nano Robotics in Medicine, Image-guided Surgical Procedures and Interventions, and Rehabilitation Robotics. The volume on Minimally Invasive Surgical Robotics focuses on robotic technologies geared towards challenges and opportunities in minimally invasive surgery and the research, design, implementation and clinical use of minimally invasive robotic systems. The volume on Micro and Nano robotics in Medicine is dedicated to research activities in an area of emerging interdisciplinary technology that is raising new scientific challenges and promising revolutionary advancement in applications such as medicine and biology. The size and range of these systems are at or below the micrometer scale and comprise assemblies of micro and nanoscale components. The volume on Image-guided Surgical Procedures and Interventions focuses primarily on the use of image guidance during surgical procedures and the challenges posed by various imaging environments and how they related to the design and development of robotic systems as well as their clinical applications. This volume also has significant contributions from the clinical viewpoint on some of the challenges in the domain of image-guided interventions. Finally, the volume on Rehabilitation Robotics is dedicated to the state-of-the-art of an emerging interdisciplinary field where robotics, sensors, and feedback are used in novel ways to re-learn, improve, or restore functional movements in humans.Volume 1, Minimally Invasive Surgical Robotics, focuses on an area of robotic applications that was established in the late 1990s, after the first robotics-assisted minimally invasive surgical procedure. This area has since received significant attention from industry and researchers. The teleoperated and ergonomic features of these robotic systems for minimally invasive surgery (MIS) have been able to reduce or eliminate most of the drawbacks of conventional (laparoscopic) MIS. Robotics-assisted MIS procedures have been conducted on over 3 million patients to date — primarily in the areas of urology, gynecology and general surgery using the FDA approved da Vinci® surgical system. The significant commercial and clinical success of the da Vinci® system has resulted in substantial research activity in recent years to reduce invasiveness, increase dexterity, provide additional features such as image guidance and haptic feedback, reduce size and cost, increase portability, and address specific clinical procedures. The area of robotic MIS is therefore in a state of rapid growth fueled by new developments in technologies such as continuum robotics, smart materials, sensing and actuation, and haptics and teleoperation. An important need arising from the incorporation of robotic technology for surgery is that of training in the appropriate use of the technology, and in the assessment of acquired skills. This volume covers the topics mentioned above in four sections. The first section gives an overview of the evolution and current state the da Vinci® system and clinical perspectives from three groups who use it on a regular basis. The second focuses on the research, and describes a number of new developments in surgical robotics that are likely to be the basis for the next generation of robotic MIS systems. The third deals with two important aspects of surgical robotic systems — teleoperation and haptics (the sense of touch). Technology for implementing the latter in a clinical setting is still very much at the research stage. The fourth section focuses on surgical training and skills assessment necessitated by the novelty and complexity of the technologies involved and the need to provide reliable and efficient training and objective assessment in the use of robotic MIS systems.In Volume 2, Micro and Nano Robotics in Medicine, a brief historical overview of the field of medical nanorobotics as well as the state-of-the-art in the field is presented in the introductory chapter. It covers the various types of nanorobotic systems, their applications and future directions in this field. The volume is divided into three themes related to medical applications. The first theme describes the main challenges of microrobotic design for propulsion in vascular media. Such nanoscale robotic agents are envisioned to revolutionize medicine by enabling minimally invasive diagnostic and therapeutic procedures. To be useful, nanorobots must be operated in complex biological fluids and tissues, which are often difficult to penetrate. In this section, a collection of four papers review the potential medical applications of motile nanorobots, catalytic-based propelling agents, biologically-inspired microrobots and nanoscale bacteria-enabled autonomous drug delivery systems. The second theme relates to the use of micro and nanorobots inside the body for drug-delivery and surgical applications. A collection of six chapters is presented in this segment. The first chapter reviews the different robot structures for three different types of surgery, namely laparoscopy, catheterization, and ophthalmic surgery. It highlights the progress of surgical microrobotics toward intracorporeally navigated mechanisms for ultra-minimally invasive interventions. Then, the design of different magnetic actuation platforms used in micro and nanorobotics are described. An overview of magnetic actuation-based control methods for microrobots, with eventually biomedical applications, is also covered in this segment. The third theme discusses the various nanomanipulation strategies that are currently used in biomedicine for cell characterization, injection, fusion and engineering. In-vitro (3D) cell culture has received increasing attention since it has been discovered to provide a better simulation environment of in-vivo cell growth. Nowadays, the rapid progress of robotic technology paves a new path for the highly controllable and flexible 3D cell assembly. One chapter in this segment discusses the applications of micro-nano robotic techniques for 3D cell culture using engineering approaches. Because cell fusion is important in numerous biological events and applications, such as tissue regeneration and cell reprogramming, a chapter on robotic-tweezers cell manipulation system to achieve precise laser-induced cell fusion using optical trapping has been included in this volume. Finally, the segment ends with a chapter on the use of novel MEMS-based characterization of micro-scale tissues instead of mechanical characterization for cell lines studies.Volume 3, Image-guided Surgical Procedures and Interventions, focuses on several aspects ranging from understanding the challenges and opportunities in this domain, to imaging technologies, to image-guided robotic systems for clinical applications. The volume includes several contributions in the area of imaging in the areas of X-Ray fluoroscopy, CT, PET, MR Imaging, Ultrasound imaging, and optical coherence tomography. Ultrasound-based diagnostics and therapeutics as well as ultrasound-guided planning and navigation are also included in this volume in addition to multi-modal imaging techniques and its applications to surgery and various interventions. The application of multi-modal imaging and fusion in the area of prostate biopsy is also covered. Imaging modality compatible robotic systems, sensors and actuator technologies for use in the MRI environment are also included in this work., as is the development of the framework incorporating image-guided modeling for surgery and intervention. Finally, there are several chapters in the clinical applications domain covering cochlear implant surgery, neurosurgery, breast biopsy, prostate cancer treatment, endovascular interventions, neurovascular interventions, robotic capsule endoscopy, and MRI-guided neurosurgical procedures and interventions.Volume 4, Rehabilitation Robotics, is dedicated to the state-of-the-art of an emerging interdisciplinary field where robotics, sensors, and feedback are used in novel ways to relearn, improve, or restore functional movements in humans. This volume attempts to cover a number of topics relevant to the field. The first section addresses an important activity in our daily lives: walking, where the neuromuscular system orchestrates the gait, posture, and balance. Conditions such as stroke, vestibular deficits, or old age impair this important activity. Three chapters on robotic training, gait rehabilitation, and cooperative orthoses describe the current works in the field to address this issue. The second section covers the significant advances in and novel designs of soft actuators and wearable systems that have emerged in the area of prosthetic lower limbs and ankles in recent years, which offer potential for both rehabilitation and human augmentation. These are described in two chapters. The next section addresses an important emphasis in the field of medicine today that strives to bring rehabilitation out from the clinic into the home environment, so that these medical aids are more readily available to users. The current state-of-the-art in this field is described in a chapter. The last section focuses on rehab devices for the pediatric population. Their impairments are life-long and rehabilitation robotics can have an even bigger impact during their lifespan. In recent years, a number of new developments have been made to promote mobility, socialization, and rehabilitation among the very young: the infants and toddlers. These aspects are summarized in two chapters of this volume.

Download or read book Handbook of Research on Holistic Perspectives in Gamification for Clinical Practice written by Novák, Daniel and published by IGI Global. This book was released on 2015-09-14 with total page 667 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past decade, the healthcare industry has adopted games as a powerful tool for promoting personal health and wellness. Utilizing principles of gamification to engage patients with positive reinforcement, these games promote stronger attention to clinical and self-care guidelines, and offer exciting possibilities for primary prevention. Targeting an audience of academics, researchers, practitioners, healthcare professionals, and even patients, the Handbook of Research on Holistic Perspectives in Gamification for Clinical Practices reviews current studies and empirical evidence, highlights critical principles of gamification, and fosters the increasing application of games at the practical, clinical level.

Download or read book Biomedical Simulation written by Fernando Bello and published by Springer. This book was released on 2014-10-10 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the thoroughly refereed conference proceedings of the 6th International Symposium on Biomedical Simulation (ISBMS) which was held in Strasbourg, France, in October 2014. Biomedical modeling and simulation are at the center stage of worldwide efforts to understand and replicate the behavior and function of the human organism. Large scale initiatives such as the Physiome Project, Virtual Physiological Human and Blue Brain Project aim to develop advanced computational models that will facilitate the understanding of the integrative function of cells, organs, and organisms, with the ultimate goal of delivering truly personalized medicine. At the same time, progress in modeling, numerical techniques and haptics has enabled more complex and interactive simulations. The 27 revised full papers (including 16 regular and 11 short papers) were carefully selected from 45 submissions and cover topics such as training systems and haptics, physics-based registration, vascular modeling and simulation, image and simulation, modeling, surgical planning, analysis, characterization and validation.

Download or read book Innovative Data Integration and Conceptual Space Modeling for COVID Cancer and Cardiac Care written by Amy Neustein and published by Academic Press. This book was released on 2022-01-18 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, scientific research and translation medicine have placed increased emphasis on computational methodology and data curation across many disciplines, both to advance underlying science and to instantiate precision-medicine protocols in the lab and in clinical practice. The nexus of concerns related to oncology, cardiology, and virology (SARS-CoV-2) presents a fortuitous context within which to examine the theory and practice of biomedical data curation. Innovative Data Integration and Conceptual Space Modeling for COVID, Cancer, and Cardiac Care argues that a well-rounded approach to data modeling should optimally embrace multiple perspectives inasmuch as data-modeling is neither a purely formal nor a purely conceptual discipline, but rather a hybrid of both. On the one hand, data models are designed for use by computer software components, and are, consequently, constrained by the mechanistic demands of software environments; data modeling strategies must accept the formal rigors imposed by unambiguous data-sharing and query-evaluation logic. In particular, data models are not well-suited for software-level deployment if such models do not translate seamlessly to clear strategies for querying data and ensuring data integrity as information is moved across multiple points. On the other hand, data modeling is, likewise, constrained by human conceptual tendencies, because the information which is managed by databases and data networks is ultimately intended to be visualized/utilized by humans as the end-user. Thus, at the intersection of both formal and humanistic methodology, data modeling takes on elements of both logico-mathematical frameworks (e.g., type systems and graph theory) and conceptual/philosophical paradigms (e.g., linguistics and cognitive science). The authors embrace this two-sided aspect of data models by seeking non-reductionistic points of convergence between formal and humanistic/conceptual viewpoints, and by leveraging biomedical contexts (viz., COVID, Cancer, and Cardiac Care) so as to provide motivating examples and case-studies in this volume. - Provides an analysis of how conceptual spaces and related cognitive linguistic approaches can inspire programming and query-processing models - Outlines the vital role that data modeling/curation has played in significant medical breakthroughs - Presents readers with an overview of how information-management approaches intersect with precision medicine, providing case studies of data-modeling in concrete scientific practice - Explores applications of image analysis and computer vision in the context of precision medicine - Examines the role of technology in scientific publishing, replication studies, and dataset curation

Download or read book Advances in Computational Plasticity written by Eugenio Oñate and published by Springer. This book was released on 2017-09-09 with total page 443 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together some 20 chapters on state-of-the-art research in the broad field of computational plasticity with applications in civil and mechanical engineering, metal forming processes, geomechanics, nonlinear structural analysis, composites, biomechanics and multi-scale analysis of materials, among others. The chapters are written by world leaders in the different fields of computational plasticity.

Download or read book Medicine Meets Virtual Reality 02 10 written by James D. Westwood and published by IOS Press. This book was released on 2002 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurement of In-vivo Force Response of Intra-abdominal Soft Tissues for Surgical Simulation -- Estimation of Soft-Tissue Model Parameters Using Registered Pre- and Postoperative Facial Surface Scans -- Virtual Endoscopy using Spherical QuickTime-VR Panorama Views -- Integration of intraoperative radiotherapy (IORT) dose distribution into the postoperative CT-based external beam radiotherapy (EBRT) treatment planing -- The application of eyeglass displays in changing the perception of pain -- Evaluation of Visualization Techniques for Image-guided Navigation in Liver Surgery -- Enhanced stereographic x-ray images -- The Communication Between Therapist and Patient in Virtual Reality: The Role of Mediation Played by Computer Technology -- Virtual Reality Assisted Cognitive Behavioral Therapy for the Treatment of Panic Disorders with Agoraphobia. -- Dextrous and Shared Interaction with Medical Data: stereoscopic vision is more important than hand-image collocation -- Usability Analysis of VR Simulation Software -- Elastically Deformable 3D Organs for Haptic Surgical Simulation -- A Generic Arthroscopy Simulator Architecture -- Virtual Reality in 3D Echocardiography: Dynamic Visualization of Atrioventricular Annuli Surface Models and Volume Rendered Doppler-Ultrasound -- Engineering and Algorithm Design for an Image Processing API: A Technical Report on ITK - the Insight Toolkit -- Finite Element (FE) Modeling of the Mandible: from Geometric Model to Tetrahedral Volumetric Mesh -- Author Index

Download or read book Computational Biomechanics for Medicine written by Poul M.F. Nielsen and published by Springer Nature. This book was released on 2022-10-31 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents contributions from the MICCAI 2021 Computational Biomechanics for Medicine Workshop. "Computational Biomechanics for Medicine - towards translation and better patient outcomes” comprises papers accepted for the MICCAI Computational Biomechanics for Medicine Workshop held virtually in conjunction with Medical Image Computing and Computer Assisted Intervention conference 2021, based in Strasbourg. The content focuses on methods and applications of computational biomechanics to medical image analysis, image-guided surgery, surgical simulation, surgical intervention planning, disease prognosis and diagnostics, analysis of injury mechanisms, implant and prostheses design, as well as artificial organ design and medical robotics. This book details state-of-the-art progress in the above fields to researchers, students, and professionals.

Download or read book Haptic Rendering for Simulation of Fine Manipulation written by Dangxiao Wang and published by Springer. This book was released on 2014-10-17 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the latest progress in six degrees of freedom (6-DoF) haptic rendering with the focus on a new approach for simulating force/torque feedback in performing tasks that require dexterous manipulation skills. One of the major challenges in 6-DoF haptic rendering is to resolve the conflict between high speed and high fidelity requirements, especially in simulating a tool interacting with both rigid and deformable objects in a narrow space and with fine features. The book presents a configuration-based optimization approach to tackle this challenge. Addressing a key issue in many VR-based simulation systems, the book will be of particular interest to researchers and professionals in the areas of surgical simulation, rehabilitation, virtual assembly, and inspection and maintenance.

Download or read book Surgical Scene Generation for Virtual Reality Based Training in Medicine written by Matthias Harders and published by Springer Science & Business Media. This book was released on 2008-03-30 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference book is for anyone involved in generating surgical training scenarios, as well as in VR-based training in general. It examines the main components required to define a scenario, in the context of surgical scene generation: Generation of the scene geometry; modelling of organ appearance; definition of biomechanical parameters. The book is the ideal reference for any reader involved in generating training scenarios, as well as in VR-based training in general.

Download or read book Natural Orifice Translumenal Endoscopic Surgery NOTES written by Anthony N. Kalloo and published by John Wiley & Sons. This book was released on 2012-04-25 with total page 637 pages. Available in PDF, EPUB and Kindle. Book excerpt: Are you interested in using NOTES to treat your patients? Do you need a multimedia tool to guide you through all aspects of clinical management? Just as laparoscopic surgery revolutionized surgical practice in the 1980’s and 90’s, offering genuine competition to traditional open surgery, Natural Orifice Translumenal Endoscopic Surgery (NOTES) presents a genuinely different alternative for surgeons and patients alike as we move forward in the 21st century. Advantages over laparoscopic surgery include lower anesthesia requirements, faster recovery and shorter hospital stays, avoidance of transabdominal wound infections, less immunosuppression, better postoperative pulmonary and diaphragmatic function and of course, the potential for "scarless" abdominal surgery. Combining high-level text with a superb companion website, Natural Orifice Translumenal Endoscopic Surgery (NOTES): Textbook and Video-Atlas provides you with a hands-on, in-depth and practical multimedia tool on this exciting breakthrough, to consult either on the ward or in surgery. Highlights include: Full coverage of the fundamentals of NOTES, its current clinical applications and techniques, and future perspectives Over 50 outstanding videos illustrating NOTES being performed by the experts Full-color throughout and superbly illustrated with over 250 figures Edited by global leaders and pioneers in the field, who have recruited a world-class contributor team As well being a valuable text for gastroenterologists, GI surgeons and general surgeons, Natural Orifice Translumenal Endoscopic Surgery (NOTES): Textbook and Video-Atlas will also appeal to urologists, urologic surgeons, gynecologists, gynecologic surgeons, thoracic and ENT surgeons.