94 research outputs found
Towards Image-Guided Pediatric Atrial Septal Defect Repair
Congenital heart disease occurs in 107.6 out of 10,000 live births, with Atrial Septal Defects (ASD) accounting for 10\% of these conditions. Historically, ASDs were treated with open heart surgery using cardiopulmonary bypass, allowing a patch to be sewn over the defect. In 1976, King et al. demonstrated use of a transcatheter occlusion procedure, thus reducing the invasiveness of ASD repair. Localization during these catheter based procedures traditionally has relied on bi-plane fluoroscopy; more recently trans-esophageal echocardiography (TEE) and intra-cardiac echocardiography (ICE) have been used to navigate these procedures. Although there is a high success rate using the transcatheter occlusion procedure, fluoroscopy poses radiation dose risk to both patient and clinician. The impact of this dose to the patients is important as many of those undergoing this procedure are children, who have an increased risk associated with radiation exposure. Their longer life expectancy than adults provides a larger window of opportunity for expressing the damaging effects of ionizing radiation. In addition, epidemiologic studies of exposed populations have demonstrated that children are considerably more sensitive to the carcinogenic effects radiation. Image-guided surgery (IGS) uses pre-operative and intra-operative images to guide surgery or an interventional procedure. Central to every IGS system is a software application capable of processing and displaying patient images, registration between multiple coordinate systems, and interfacing with a tool tracking system. We have developed a novel image-guided surgery framework called Kit for Navigation by Image Focused Exploration (KNIFE). This software system serves as the core technology by which a system for reduction of radiation exposure to pediatric patients was developed. The bulk of the initial work in this research endevaour was the development of KNIFE which itself went through countless iterations before arriving at its current state as per the feature requirements established. Secondly, since this work involved the use of captured medical images and their use in an IGS software suite, a brief analysis of the physics behind the images was conducted. Through this aspect of the work, intrinsic parameters (principal point and focal point) of the fluoroscope were quantified using a 3D grid calibration phantom. A second grid phantom was traversed through the fluoroscopic imaging volume of II and flat panel based systems at 2 cm intervals building a scatter field of the volume to demonstrate pincushion and \u27S\u27 distortion in the images. Effects of projection distortion on the images was assessed by measuring the fiducial registration error (FRE) of each point used in two different registration techniques, where both methods utilized ordinary procrustes analysis but the second used a projection matrix built from the fluoroscopes calculated intrinsic parameters. A case study was performed to test whether the projection registration outperforms the rigid transform only. Using the knowledge generated were able to successfully design and complete mock clinical procedures using cardiac phantom models. These mock trials at the beginning of this work used a single point to represent catheter location but this was eventually replaced with a full shape model that offered numerous advantages. At the conclusion of this work a novel protocol for conducting IG ASD procedures was developed. Future work would involve the construction of novel EM tracked tools, phantom models for other vascular diseases and finally clinical integration and use
Design and analysis of MAC protocols for wireless networks
During the last few years, wireless networking has attracted much of the research and industry interest. In addition, almost all current wireless devices are based on the IEEE 802.11 and IEEE 802.16 standards for the local and metropolitan area networks (LAN/MAN) respectively. Both of these standards define the medium access control layer (MAC) and physical layer (PHY) parts of a wireless user. In a wireless network, the MAC protocol plays a significant role in determining the performance of the whole network and individual users. Accordingly, many challenges are addressed by research to improve the performance of MAC operations in IEEE 802.11 and IEEE 802.16 standards. Such performance is measured using different metrics like the throughput, fairness, delay, utilization, and drop rate.
We propose new protocols and solutions to enhance the performance of an IEEE 802.11 WLAN (wireless LAN) network, and to enhance the utilization of an IEEE 802.16e WMAN (wireless MAN). First, we propose a new protocol called HDCF (High-performance Distributed Coordination Function), to address the problem of wasted time, or idle slots and collided frames, in contention resolution of the IEEE 802.11 DCF. Second, we propose a simple protocol that enhances the performance of DCF in the existence of the hidden terminal problem. Opposite to other approaches, the proposed protocol attempts to benefit from the hidden terminal problem. Third, we propose two variants of a simple though effective distributed scheme, called NZ-ACK (Non Zero-Acknowledgement), to address the effects of coexisting IEEE 802.11e EDCA and IEEE 802.11 DCF devices. Finally, we investigate encouraging ertPS (enhanced real time Polling Service) connections, in an IEEE 802.16e, network to benefit from contention, and we aim at improving the network performance without violating any delay requirements of voice applications
TOWARDS A CREATIVE SUSTAINABLE PROMENADE IN INFORMAL SOUK ARCHITECTURECASE STUDY: MAR ELIAS CAMPS, IN BEIRUT, LEBANON
Informal settlement and slums are from the past decades growing continuously with urbanization, where informal souk or small market propagate informally in slums. Mainly the informal settlement is defined as residential areas where a group of housing has been constructed on land to which the occupants have an illegal claim. These informal settlement maintain few shops in unorganized way which influence the economic conditions. There are also the lack of open spaces where small alleys are mainly allocated in these informal urban fabric. The main aim is to provide a new applicable and better living condition, by providing new retails and promenade path. For that reason, this paper focuses on the principles of how movement occurs within the slums, informal settlement and the built environment, and mainly presents a case study strategy which analyze in depth interviews, group discussion with residents, records, observations and measurements of informal settlement. Moreover the paper declares that the informally created open spaces and movement paths are formed on the basis of social relation, and economic practical problems. In conclusion, an analyzed new promenade path presented as an architectural souk in informal settlement based on theories and practices on movement architecture will be declared and analyzed
Legumes as basic ingredients in the production of dairy-free cheese alternatives: a review
Research into dairy-free alternative products, whether plant-based or cell-based, is growing fast and the food industry is facing a new challenge of creating innovative, nutritious, accessible, and natural dairy-free cheese alternatives. The market demand for these products is continuing to increase owing to more people choosing to reduce or eliminate meat and dairy products from their diet for health, environmental sustainability, and/or ethical reasons. This review investigates the current status of dairy product alternatives. Legume proteins have good technological properties and are cheap, which gives them a strong commercial potential to be used in plant-based cheese-like products. However, few legume proteins have been explored in the formulation, development, and manufacture of a fully dairy-free cheese because of their undesirable properties: heat stable anti-nutritional factors and a beany flavor. These can be alleviated by novel or traditional and economical techniques. The improvement and diversification of the formulation of legume-based cheese alternatives is strongly suggested as a low-cost step towards more sustainable food chains. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry
Systems and Methods for Image Guided Surgery
Systems and methods for image guided surgery are disclosed herein. An example method can include: receiving a plurality of 2D projection images of an object at a plurality of projection angles during a first period of time; and receiving a position of an instrument relative to a tracking coordinate system during the first period of time. The method can also include registering the plurality of 2D projection images relative to the tracking coordinate system to obtain a transformation function that defines a relationship between a coordinate system of the plurality of 2D projection images and the tracking coordinate system; receiving an adjusted position of the instrument relative to the tracking coordinate system during a second period of time that is subsequent to the first period of time; and estimating an adjusted position of the instrument relative to the plurality of 2D projection images using the transformation function
EXPLORING THE QUALITIES OF CHILD-FRIENDLY OUTDOOR SPACES: A FIELD STUDY IN LOW INCOME NEIGHBOURHOODS - CASE STUDY: SABRA, BEIRUT, LEBANON
Children’s play areas are from the past an indispensable right for children, in which it allows children to build their physical environment and assess it cognitive thinking. But today, the city, especially in low-income population suffers from a clear shortage of open spaces, where the leftover spaces are left empty used for garbage, old tanks car parts, and many other bad issues. This has negatively affected society, mainly children, where they become vulnerable to many social ills and problems that threaten their lives and behaviour. This paper tries to ameliorate and presents adequate children’s play areas, for the low-income population, through an analytical example, suffering from a lack of playing spaces between residential buildings, and show us how responsible and associations find a clear and appropriate solution for their society. For that reason, the paper focuses on principles of how to present safe playing areas and to be accessible by all children without inequality between boys and girls, and it also presents a case study that analyses the current situation presented in this region, in order to solve it. Moreover, the paper declares that the low-income population living in the high-density urban fabric, can manage and form suitable public and kid’s gatherings, or may take advantage of good use of existing public open areas, where these can improve social relations and develop children’s physical environment. In order to survey the current situation of the case study, Sabra, the paper follows a field methodology using a questionnaire. This methodology shows the complications of low-income Sabra inhabitants and children and concluded with guidelines to ameliorate and enhance the quality of life and upgrade adequate outdoor spaces for play
الموقع الجغرافي كمحدّد للسياسة الخارجية (دراسة حالة الأردن)
هدف المقال التعرف إلى أثر الموقع الجغرافي على السياسة الخارجية الأردنية من خلال مناقشة محور القضية الفلسطينية ومحوريْ اللجوء والإرهاب اللذيْن نتجا عن الربيع العربي، وقد استخدمت الدراسة المنهج الوصفي التحليلي ومنهج دراسة الحالة للتحقق من صحة فرضيتها القائلة بوجود علاقة ارتباطية بين موقع الأردن الجغرافي، وبين سياسته الخارجية. وقد تبيّن للدراسة بأن الموقع الجغرافي للأردن قد حكمه بتوجه سياسي معين، فبخصوص قرب الأردن من فلسطين، توجّه الأردن نحو الموازنة بين القوى العربية السياسية المجاورة وإدامة العلاقات الجيدة معها، واتّباع سياسة خارجية بعيدة عن إثارة الحساسيات مع دول الجوار الجغرافي، أما بخصوص أزمة اللجوء التي نتجت عن الربيع العربي وأبرزها أزمة اللجوء السوري، فقد وجدت الدراسة أن الأزمة السورية قد أدّت إلى تعطيل حركة التجارة الأردنية بسبب إغلاق الحدود السورية الأردنية إلى جانب إغلاق الحدود العراقية الأردنية بسبب الاضطرابات الأمنية، الأمر الذي أثر بشكلٍ كبير على الاقتصاد الأردني، وفيما يتعلق بمحور الإرهاب، فقد اتخذ الأردن سمة الاعتدال والتوازن، ودافع عن وسطية الإسلام في المحافل الدولية. أوصت الدراسة بزيادة التحشيد والدعم والتأييد لمواقف الأردن من القضية الفلسطينية، ورفض أي حلول على حسابه مهما كانت، والانفتاح على الأزمة السورية والتعاون مع الدول العظمى والإقليمية لحلها
Security and Stability of the Gulf Region in Light of Iranian Threats
The study aimed to examine the strategies of the Arab Gulf states to address the Iranian threat, and also seeks to identify the extent to which the United States adheres to international law in its policy towards the treatment of weapons of mass destruction in the Gulf region, and also seeks to clarify the risks and potential Iranian threats now and in the future of the Arab Gulf states, which will instill concern and fear among the Arab Gulf states in what will result under the Iranian agreement and the countries (5+1), and a regional neighbor with ambitions in the region in general, and use in the historical and analytical approach, and the use of the methodology, historical and analytical, The study concluded that the continuation of the State of Iran and its unlimited pursuit of nuclear technology, prompts the countries of the region to follow in the footsteps of the Iranians, permeably under the pretext of peaceful civilian purpose, and at the same time we find that an unstable region such as the Arab region and the fear of the danger expected from Iran may be the motive and the real reason behind the pursuit of nuclear technology by others in the region. Keywords: The Arabian Gulf region, Iranian threats. DOI: 10.7176/IAGS/85-03 Publication date:August 31st 202
Devices that cooperate with ultrasound probes for muscoskeletal evaluations and related systems and methods
Adaptors for ultrasound probes can have an adaptor body can have an open lower end that allows a distal end of the ultrasound probe to extend therethrough to contact skin of a patient. The adaptor can include a plurality of spaced apart resilient members held by the adaptor body that, in operation, are able to change in length such that the resilient members translate from a first longer length to a second shorter length when the probe applies compressive force to the target tissue
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