Sample records for integrated model-based neurosurgical

  1. Model-Based Integration and Interpretation of Data

    DEFF Research Database (Denmark)

    Petersen, Johannes


    Data integration and interpretation plays a crucial role in supervisory control. The paper defines a set of generic inference steps for the data integration and interpretation process based on a three-layer model of system representations. The three-layer model is used to clarify the combination...... of constraint and object-centered representations of the work domain throwing new light on the basic principles underlying the data integration and interpretation process of Rasmussen's abstraction hierarchy as well as other model-based approaches combining constraint and object-centered representations. Based...

  2. Modular Architecture for Integrated Model-Based Decision Support. (United States)

    Gaebel, Jan; Schreiber, Erik; Oeser, Alexander; Oeltze-Jafra, Steffen


    Model-based decision support systems promise to be a valuable addition to oncological treatments and the implementation of personalized therapies. For the integration and sharing of decision models, the involved systems must be able to communicate with each other. In this paper, we propose a modularized architecture of dedicated systems for the integration of probabilistic decision models into existing hospital environments. These systems interconnect via web services and provide model sharing and processing capabilities for clinical information systems. Along the lines of IHE integration profiles from other disciplines and the meaningful reuse of routinely recorded patient data, our approach aims for the seamless integration of decision models into hospital infrastructure and the physicians' daily work.

  3. Neurosurgical Hyponatremia

    Directory of Open Access Journals (Sweden)

    Mark J. Hannon


    Full Text Available Hyponatremia is a frequent electrolyte imbalance in hospital inpatients. Acute onset hyponatremia is particularly common in patients who have undergone any type of brain insult, including traumatic brain injury, subarachnoid hemorrhage and brain tumors, and is a frequent complication of intracranial procedures. Acute hyponatremia is more clinically dangerous than chronic hyponatremia, as it creates an osmotic gradient between the brain and the plasma, which promotes the movement of water from the plasma into brain cells, causing cerebral edema and neurological compromise. Unless acute hyponatremia is corrected promptly and effectively, cerebral edema may manifest through impaired consciousness level, seizures, elevated intracranial pressure, and, potentially, death due to cerebral herniation. The pathophysiology of hyponatremia in neurotrauma is multifactorial, but most cases appear to be due to the syndrome of inappropriate antidiuretic hormone secretion (SIADH. Classical treatment of SIADH with fluid restriction is frequently ineffective, and in some circumstances, such as following subarachnoid hemorrhage, contraindicated. However, the recently developed vasopressin receptor antagonist class of drugs provides a very useful tool in the management of neurosurgical SIADH. In this review, we summarize the existing literature on the clinical features, causes, and management of hyponatremia in the neurosurgical patient.

  4. Medical Device Integration Model Based on the Internet of Things (United States)

    Hao, Aiyu; Wang, Ling


    At present, hospitals in our country have basically established the HIS system, which manages registration, treatment, and charge, among many others, of patients. During treatment, patients need to use medical devices repeatedly to acquire all sorts of inspection data. Currently, the output data of the medical devices are often manually input into information system, which is easy to get wrong or easy to cause mismatches between inspection reports and patients. For some small hospitals of which information construction is still relatively weak, the information generated by the devices is still presented in the form of paper reports. When doctors or patients want to have access to the data at a given time again, they can only look at the paper files. Data integration between medical devices has long been a difficult problem for the medical information system, because the data from medical devices are lack of mandatory unified global standards and have outstanding heterogeneity of devices. In order to protect their own interests, manufacturers use special protocols, etc., thus causing medical decices to still be the "lonely island" of hospital information system. Besides, unfocused application of the data will lead to failure to achieve a reasonable distribution of medical resources. With the deepening of IT construction in hospitals, medical information systems will be bound to develop towards mobile applications, intelligent analysis, and interconnection and interworking, on the premise that there is an effective medical device integration (MDI) technology. To this end, this paper presents a MDI model based on the Internet of Things (IoT). Through abstract classification, this model is able to extract the common characteristics of the devices, resolve the heterogeneous differences between them, and employ a unified protocol to integrate data between devices. And by the IoT technology, it realizes interconnection network of devices and conducts associate matching

  5. Integrating Design Decision Management with Model-based Software Development

    DEFF Research Database (Denmark)

    Könemann, Patrick

    Design decisions are continuously made during the development of software systems and are important artifacts for design documentation. Dedicated decision management systems are often used to capture such design knowledge. Most such systems are, however, separated from the design artifacts...... of the system. In model-based software development, where design models are used to develop a software system, outcomes of many design decisions have big impact on design models. The realization of design decisions is often manual and tedious work on design models. Moreover, keeping design models consistent......, or by ignoring the causes. This substitutes manual reviews to some extent. The concepts, implemented in a tool, have been validated with design patterns, refactorings, and domain level tests that comprise a replay of a real project. This proves the applicability of the solution to realistic examples...

  6. Design of model based LQG control for integrated building systems

    NARCIS (Netherlands)

    Yahiaoui, A.; Hensen, J.L.M.; Soethout, L.L.; Paassen, van A.H.C.


    The automation of the operation of integrated building systems requires using modern control techniques to enhance the quality of the building indoor environments. This paper describes the theatrical base and practical application of an optimal dynamic regulator using modelbased Linear Quadratic

  7. Integrated model-based retargeting and optical proximity correction (United States)

    Agarwal, Kanak B.; Banerjee, Shayak


    Conventional resolution enhancement techniques (RET) are becoming increasingly inadequate at addressing the challenges of subwavelength lithography. In particular, features show high sensitivity to process variation in low-k1 lithography. Process variation aware RETs such as process-window OPC are becoming increasingly important to guarantee high lithographic yield, but such techniques suffer from high runtime impact. An alternative to PWOPC is to perform retargeting, which is a rule-assisted modification of target layout shapes to improve their process window. However, rule-based retargeting is not a scalable technique since rules cannot cover the entire search space of two-dimensional shape configurations, especially with technology scaling. In this paper, we propose to integrate the processes of retargeting and optical proximity correction (OPC). We utilize the normalized image log slope (NILS) metric, which is available at no extra computational cost during OPC. We use NILS to guide dynamic target modification between iterations of OPC. We utilize the NILS tagging capabilities of Calibre TCL scripting to identify fragments with low NILS. We then perform NILS binning to assign different magnitude of retargeting to different NILS bins. NILS is determined both for width, to identify regions of pinching, and space, to locate regions of potential bridging. We develop an integrated flow for 1x metal lines (M1) which exhibits lesser lithographic hotspots compared to a flow with just OPC and no retargeting. We also observe cases where hotspots that existed in the rule-based retargeting flow are fixed using our methodology. We finally also demonstrate that such a retargeting methodology does not significantly alter design properties by electrically simulating a latch layout before and after retargeting. We observe less than 1% impact on latch Clk-Q and D-Q delays post-retargeting, which makes this methodology an attractive one for use in improving shape process windows

  8. Spinal subspecialization in post-graduate neurosurgical education. (United States)

    Toyota, Brian D


    The growing science and technology of various neurosurgical areas fosters subspecialization. The transmission of this expanding knowledge base to the neurosurgical resident becomes an increasing challenge. A survey of neurosurgical residency program directors was undertaken to evaluate their response to the budding subspecialization of spine surgery within general neurosurgery. A survey requesting background data, educational infrastructure and prevailing opinion was distributed to all 13 neurosurgical program directors in Canada. The responses were tabulated and results recorded. It is upon these results that conclusions and proposed directions are based. The current practice of the overwhelming majority of Canadian academic neurosurgical centers is to have neurosurgical spinal subspecialists working under the umbrella of the general neurosurgical division. A large percentage of neurosurgical program directors in Canada believe that the management of spinal disease, including both intradural procedures and instrumentation, is and should remain an integral part of general neurosurgical training. A consensus statement regarding the requirements of neurosurgical training in spinal disorders is the expressed desire of almost all program directors. A proposed direction and resolution is discussed.

  9. Neurosurgical procedures in pregnancy

    Directory of Open Access Journals (Sweden)

    Cirak Bayram


    Full Text Available PURPOSE: Over the past few decades maternal mortality has progressively declined because of improved management of the major obstetric problems of hemorrhage, infection, and toxemia. As a result, the relative incidence of deaths resulting from non obstetric causes has increased. Chief among nonobstetric causes are neurologic disorders. Those most common during pregnancy are low back pain, intracranial tumors, subarachnoid hemorrhage, and neurotrauma. The management of the neurosurgical pathologies during pregnancy needs some specifications for both the mother and the fetus. METHODS: We performed a retrospective study evaluating the clinical, radiological, and surgical characteristics of 9 patients who have cranial neuropathologies and have undergone neurosurgical intervention. RESULTS: Most of the patients in this study had vaginal delivery. Prominent neurosurgical disease related to cerebral damage. Every patient underwent a laboratory and radiological evaluation. All except one survived the neurosurgical pathology. Neither baby nor mother had significant problem during delivery and neurosurgical intervention. CONCLUSION: Pregnant women may face to every kind of neurosurgical pathology that nonpregnant women have faced. In addition, pregnancy itself, gives rise some metabolic changes in the women and those changes may cause some neurologic pathologies to be symptomatic or to aggravate the present symptomatology. Because of those reasons, close neurologic follow up of a pregnant woman is of vital importance. At the end of a pregnancy having experienced some neurologic interventions including diagnostic evaluation or surgical intervention does not necessitates the cesarean section for a neurologically intact infant and mother.

  10. Integration of supervisory control synthesis in model-based systems engineering

    NARCIS (Netherlands)

    Baeten, J.C.M.; van de Mortel - Fronczak, J.M.; Rooda, J.E.


    Increasing system complexity, time to market and development costs reduction place higher demands on engineering processes. Formal models play an important role here because they enable the use of various model-based analyses and early integration techniques and tools. Engineering processes based on

  11. State of the Art : Integrated Management of Requirements in Model-Based Software Engineering


    Thörn, Christer


    This report describes the background and future of research concerning integrated management of requirements in model-based software engineering. The focus is on describing the relevant topics and existing theoretical backgrounds that form the basis for the research. The report describes the fundamental difficulties of requirements engineering for software projects, and proposes that the results and methods of models in software engineering can help leverage those problems. Taking inspiration...

  12. Retraction of Neurosurgical Publications: A Systematic Review. (United States)

    Wang, Justin; Ku, Jerry C; Alotaibi, Naif M; Rutka, James T


    Despite the increasing awareness of scientific fraud, no attempt has been made to assess its prevalence in neurosurgery. The aim of our review was to assess the chronologic trend, reasons, research type/design, and country of origin of retracted neurosurgical publications. Three independent reviewers searched the EMBASE and MEDLINE databases using neurosurgical keywords for retracted articles from 1995 to 2016. Archives of retracted articles ( and the independent Web sites of neurosurgical journals were also searched. Data including the journal, impact factor, reason for retraction, country of origin, and citations were extracted. A total of 97 studies were included for data extraction. Journal impact factor ranged from 0.57 to 35.03. Most studies (61) were retracted within the last 5 years. The most common reason for retraction was because of a duplicated publication found elsewhere (26), followed closely by plagiarism (22), or presenting fraudulent data (14). Other reasons included scientific errors/mistakes, author misattribution, and compromised peer review. Articles originated from several countries and some were widely cited. Retractions of neurosurgical publications are increasing significantly, mostly because of issues of academic integrity, including duplicate publishing and plagiarism. Implementation of more transparent data-sharing repositories and thorough screening of data before manuscript submission, as well as additional educational programs for new researchers, may help mitigate these issues in the future. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Mechanical ventilation in neurosurgical patients

    Directory of Open Access Journals (Sweden)

    Keshav Goyal


    Full Text Available Mechanical ventilation significantly affects cerebral oxygenation and cerebral blood flow through changes in arterial carbon dioxide levels. Neurosurgical patients might require mechanical ventilation for correction and maintenance of changes in the pulmonary system that occur either due to neurosurgical pathology or following surgery during the acute phase. This review discusses the basics of mechanical ventilation relevant to the neurosurgeon in the day-to-day management of neurosurgical patient requiring artificial support of the respiration.

  14. The Value of Neurosurgical and Intraoperative Magnetic Resonance Imaging and Diffusion Tensor Imaging Tractography in Clinically Integrated Neuroanatomy Modules: A Cross-Sectional Study (United States)

    Familiari, Giuseppe; Relucenti, Michela; Heyn, Rosemarie; Baldini, Rossella; D'Andrea, Giancarlo; Familiari, Pietro; Bozzao, Alessandro; Raco, Antonino


    Neuroanatomy is considered to be one of the most difficult anatomical subjects for students. To provide motivation and improve learning outcomes in this area, clinical cases and neurosurgical images from diffusion tensor imaging (DTI) tractographies produced using an intraoperative magnetic resonance imaging apparatus (MRI/DTI) were presented and…

  15. Integration of model-based control systems with artificial intelligence and workstations

    International Nuclear Information System (INIS)

    Lee, M.; Clearwater, S.


    Experience with model based accelerator control started at SPEAR. Since that SPEAR. Since that time nearly all accelerator beam lines have been controlled using model-based application programs, for example, PEP and SLC at SLAC. In order to take advantage of state-of-the-art hardware and software technology, the design and implementation of the accelerator control programs have undergone radical changes with time. Consequently, SPEAR, PEP, and SLC all use different control programs. Since many of these application programs are imbedded deep into the control system, they had to be rewritten each time. Each time this rewriting has occurred a great deal of time and effort has been spent on training physicists and programmers to do the job. Now, these application programs have been developed for a fourth time. This time, however, the programs being developed are generic so that they will not have to be done again. An integrated system called GOLD (Generic Orbit ampersand Lattice Debugger) has been developed for debugging and correcting trajectory errors in accelerator lattices. The system consists of a lattice modeling program (COMFORT), a beam simulator (PLUS), a graphical workstation environment (micro-VAX) and an expert system (ABLE). This paper will describe some of the features and applications of our integrated system with emphasis on the automation offered by expert systems. 5 refs., 4 figs

  16. GOLD: Integration of model-based control systems with artificial intelligence and workstations

    International Nuclear Information System (INIS)

    Lee, M.; Clearwater, S.


    Our experience with model-based accelerator control started at SPEAR. Since that time nearly all accelerator beamlines have been controlled using model-based application programs, for example, PEP and SLC at SLAC. In order to take advantage of state-of-the-art hardware and software technology, the design and implementation of the accelerator control programs have undergone radical changes with time. Consequently, SPEAR, PEP and SLC all use different control programs. Since many of these application programs are embedded deep into the control system, they had to be rewritten each time. Each time this rewriting has occurred a great deal of time and effort has been spent on training physicists and programmers to do the job. Now, we have developed an integrated system called GOLD (Genetic Orbit and Lattice Debugger) for debugging and correcting trajectory errors in accelerator lattices. The system consists of a lattice modeling program (COMFORT), a beam simulator (PLUS), a graphical workstation environment (micro-VAX) and an expert system (ABLE). This paper will describe some of the features and applications of our integrated system with emphasis on the automation offered by expert systems. 5 refs

  17. GOLD: Integration of model-based control systems with artificial intelligence and workstations

    International Nuclear Information System (INIS)

    Lee, M.; Clearwater, S.


    Our experience with model based accelerator control started at SPEAR. Since that time nearly all accelerator beam lines have been controlled using model-based application programs, for example, PEP and SLC at SLAC. In order to take advantage of state-of-the-art hardware and software technology, the design and implementation of the accelerator control programs have undergone radical change with time. Consequently, SPEAR, PEP, and SLC all use different control programs. Since many of these application programs are imbedded deep into the control system, they had to be rewritten each time. Each time this rewriting has occurred a great deal of time and effort has been spent on training physicists and programmers to do the job. Now, we have developed these application programs for a fourth time. This time, however, the programs we are developing are generic so that we will not have to do it again. We have developed an integrated system called GOLD (Generic Orbit and Lattice Debugger) for debugging and correcting trajectory errors in accelerator lattices. The system consists of a lattice modeling program (COMFORT), a beam simulator (PLUS), a graphical workstation environment (micro-VAX) and an expert system (ABLE). This paper will describe some of the features and applications of our integrated system with emphasis on the automation offered by expert systems. 5 refs

  18. Towards An Intelligent Model-Based Decision Support System For An Integrated Oil Company (EGPC)

    International Nuclear Information System (INIS)

    Khorshid, M.; Hassan, H.; Abdel Latife, M.A.


    Decision Support System (DSS) is an interactive, flexible and adaptable computer-based support system specially developed for supporting the solution of unstructured management problems [31] DSS has become widespread for oil industry domain in recent years. The computer-based DSS, which were developed and implemented in oil industry, are used to address the complex short-term planning and operational issues associated with downstream industry. Most of these applications concentrate on the data-centered tools, while the model-centered applications of DSS are still very limited up till now [20]. This study develops an Intelligent Model-Based DSS for an integrated oil company, to help policy makers and petroleum planner in improving the effectiveness of the strategic planning in oil sector. This domain basically imposes semi-structured or unstructured decisions and involves a very complex modeling process

  19. An Integrated Model Based on a Hierarchical Indices System for Monitoring and Evaluating Urban Sustainability

    Directory of Open Access Journals (Sweden)

    Xulin Guo


    Full Text Available Over 50% of world’s population presently resides in cities, and this number is expected to rise to ~70% by 2050. Increasing urbanization problems including population growth, urban sprawl, land use change, unemployment, and environmental degradation, have markedly impacted urban residents’ Quality of Life (QOL. Therefore, urban sustainability and its measurement have gained increasing attention from administrators, urban planners, and scientific communities throughout the world with respect to improving urban development and human well-being. The widely accepted definition of urban sustainability emphasizes the balancing development of three primary domains (urban economy, society, and environment. This article attempts to improve the aforementioned definition of urban sustainability by incorporating a human well-being dimension. Major problems identified in existing urban sustainability indicator (USI models include a weak integration of potential indicators, poor measurement and quantification, and insufficient spatial-temporal analysis. To tackle these challenges an integrated USI model based on a hierarchical indices system was established for monitoring and evaluating urban sustainability. This model can be performed by quantifying indicators using both traditional statistical approaches and advanced geomatic techniques based on satellite imagery and census data, which aims to provide a theoretical basis for a comprehensive assessment of urban sustainability from a spatial-temporal perspective.

  20. Integrating model checking with HiP-HOPS in model-based safety analysis

    International Nuclear Information System (INIS)

    Sharvia, Septavera; Papadopoulos, Yiannis


    The ability to perform an effective and robust safety analysis on the design of modern safety–critical systems is crucial. Model-based safety analysis (MBSA) has been introduced in recent years to support the assessment of complex system design by focusing on the system model as the central artefact, and by automating the synthesis and analysis of failure-extended models. Model checking and failure logic synthesis and analysis (FLSA) are two prominent MBSA paradigms. Extensive research has placed emphasis on the development of these techniques, but discussion on their integration remains limited. In this paper, we propose a technique in which model checking and Hierarchically Performed Hazard Origin and Propagation Studies (HiP-HOPS) – an advanced FLSA technique – can be applied synergistically with benefit for the MBSA process. The application of the technique is illustrated through an example of a brake-by-wire system. - Highlights: • We propose technique to integrate HiP-HOPS and model checking. • State machines can be systematically constructed from HiP-HOPS. • The strengths of different MBSA techniques are combined. • Demonstrated through modeling and analysis of brake-by-wire system. • Root cause analysis is automated and system dynamic behaviors analyzed and verified

  1. Model Based Optimization of Integrated Low Voltage DC-DC Converter for Energy Harvesting Applications (United States)

    Jayaweera, H. M. P. C.; Muhtaroğlu, Ali


    A novel model based methodology is presented to determine optimal device parameters for the fully integrated ultra low voltage DC-DC converter for energy harvesting applications. The proposed model feasibly contributes to determine the maximum efficient number of charge pump stages to fulfill the voltage requirement of the energy harvester application. The proposed DC-DC converter based power consumption model enables the analytical derivation of the charge pump efficiency when utilized simultaneously with the known LC tank oscillator behavior under resonant conditions, and voltage step up characteristics of the cross-coupled charge pump topology. The verification of the model has been done using a circuit simulator. The optimized system through the established model achieves more than 40% maximum efficiency yielding 0.45 V output with single stage, 0.75 V output with two stages, and 0.9 V with three stages for 2.5 kΩ, 3.5 kΩ and 5 kΩ loads respectively using 0.2 V input.

  2. Integration of supervisory control synthesis in model-based systems engineering

    NARCIS (Netherlands)

    Baeten, J.C.M.; Mortel - Fronczak, van de J.M.; Rooda, J.E.


    Due to increasing system complexity, time-to-market and development costs reduction, there are higher demands on engineering processes. Model-based engineering can play a role here because it supports system development by enabling the use of various model-based analysis techniques and tools. As a

  3. Model-based identification and use of task complexity factors of human integrated systems

    International Nuclear Information System (INIS)

    Ham, Dong-Han; Park, Jinkyun; Jung, Wondea


    Task complexity is one of the conceptual constructs that are critical to explain and predict human performance in human integrated systems. A basic approach to evaluating the complexity of tasks is to identify task complexity factors and measure them. Although a great deal of task complexity factors have been studied, there is still a lack of conceptual frameworks for identifying and organizing them analytically, which can be generally used irrespective of the types of domains and tasks. This study proposes a model-based approach to identifying and using task complexity factors, which has two facets—the design aspects of a task and complexity dimensions. Three levels of design abstraction, which are functional, behavioral, and structural aspects of a task, characterize the design aspect of a task. The behavioral aspect is further classified into five cognitive processing activity types. The complexity dimensions explain a task complexity from different perspectives, which are size, variety, and order/organization. Twenty-one task complexity factors are identified by the combination of the attributes of each facet. Identification and evaluation of task complexity factors based on this model is believed to give insights for improving the design quality of tasks. This model for complexity factors can also be used as a referential framework for allocating tasks and designing information aids. The proposed approach is applied to procedure-based tasks of nuclear power plants (NPPs) as a case study to demonstrate its use. Last, we compare the proposed approach with other studies and then suggest some future research directions.

  4. The Currarino triad: neurosurgical considerations

    NARCIS (Netherlands)

    Emans, P.J.; van Aalst, J.; van Heurn, L.W.E.; Marcelis, C.; Kootstra, G.; Beets-Tan, R.G.H.; Vles, J.S.; Beuls, E.A.


    OBJECTIVES: The Currarino triad, a relatively uncommon hereditary disorder, is often associated with tethered cord and anterior myelomeningocele. Little is known of the implications of these neuroanatomic malformations or of the neurosurgical attitude. The objective of this study is to identify the

  5. Model-Based Design and Integration of Large Li-ion Battery Systems

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Kandler; Kim, Gi-Heon; Santhanagopalan, Shriram; Shi, Ying; Pesaran, Ahmad; Mukherjee, Partha; Barai, Pallab; Maute, Kurt; Behrou, Reza; Patil, Chinmaya


    This presentation introduces physics-based models of batteries and software toolsets, including those developed by the U.S. Department of Energy's (DOE) Computer-Aided Engineering for Electric-Drive Vehicle Batteries Program (CAEBAT). The presentation highlights achievements and gaps in model-based tools for materials-to-systems design, lifetime prediction and control.

  6. Neurosurgical Practice in Transition: A Review. (United States)

    Kim, Dong H; Dagi, T Forcht; Bean, James R


    Neurosurgery is experiencing a period of acute change driven by 2 forces: (1) the perception that the healthcare system in the United States is wasteful and that patients are receiving low "value" care, (2) the belief that quality and long-term outcomes can be measured accurately. We believe 3 important shifts will emerge as a result of these forces. First, payment models will change. They will become anchored to a concept of population health, with capitation payments on a per-patient basis going to provider entities that undertake financial risk. Second, fee-for-service payments will be tied increasingly to administrative and clinical quality measures. Finally, out-of-pocket costs for patients will increase and affect both treatment decisions and willingness to participate in restrictive health care networks. In this review, we describe these changes and discuss possible consequences. We note the changing demographics of neurosurgical practices. Overall, independent private practices, managed by the neurosurgeons, will decline. The proportion of fee-for-service cases will decrease while cases reimbursed through capitation will increase. Physician integration with provider organizations, whether via full employment, a "lease," or some other arrangement, will also increase. We note the increasing importance of quality measures, and how they are likely to affect neurosurgical practices and reimbursement. We describe the advantages and disadvantages of fee-for-service and population health; describe opportunities and risks arising from these transitions; and outline strategies to thrive in a changing environment. Copyright © 2016 by the Congress of Neurological Surgeons.

  7. Pulmonary complications in neurosurgical patients

    Directory of Open Access Journals (Sweden)

    Randeep Guleria


    Full Text Available Pulmonary complications are a major cause of morbidity and mortality in neurosurgical patients. The common pulmonary complications in neurosurgical patients include pneumonia, postoperative atelectasis, respiratory failure, pulmonary embolism, and neurogenic pulmonary edema. Postoperative lung expansion strategies have been shown to be useful in prevention of the postoperative complications in surgical patients. Low tidal volume ventilation should be used in patients who develop acute respiratory distress syndrome. An antibiotic use policy should be put in practice depending on the local patterns of antimicrobial resistance in the hospital. Thromboprophylactic strategies should be used in nonambulatory patients. Meticulous attention should be paid to infection control with a special emphasis on hand-washing practices. Prevention and timely management of these complications can help to decrease the morbidity and mortality associated with pulmonary complications.

  8. A Framework for Sharing and Integrating Remote Sensing and GIS Models Based on Web Service (United States)

    Chen, Zeqiang; Lin, Hui; Chen, Min; Liu, Deer; Bao, Ying; Ding, Yulin


    Sharing and integrating Remote Sensing (RS) and Geographic Information System/Science (GIS) models are critical for developing practical application systems. Facilitating model sharing and model integration is a problem for model publishers and model users, respectively. To address this problem, a framework based on a Web service for sharing and integrating RS and GIS models is proposed in this paper. The fundamental idea of the framework is to publish heterogeneous RS and GIS models into standard Web services for sharing and interoperation and then to integrate the RS and GIS models using Web services. For the former, a “black box” and a visual method are employed to facilitate the publishing of the models as Web services. For the latter, model integration based on the geospatial workflow and semantic supported marching method is introduced. Under this framework, model sharing and integration is applied for developing the Pearl River Delta water environment monitoring system. The results show that the framework can facilitate model sharing and model integration for model publishers and model users. PMID:24901016

  9. A framework for sharing and integrating remote sensing and GIS models based on Web service. (United States)

    Chen, Zeqiang; Lin, Hui; Chen, Min; Liu, Deer; Bao, Ying; Ding, Yulin


    Sharing and integrating Remote Sensing (RS) and Geographic Information System/Science (GIS) models are critical for developing practical application systems. Facilitating model sharing and model integration is a problem for model publishers and model users, respectively. To address this problem, a framework based on a Web service for sharing and integrating RS and GIS models is proposed in this paper. The fundamental idea of the framework is to publish heterogeneous RS and GIS models into standard Web services for sharing and interoperation and then to integrate the RS and GIS models using Web services. For the former, a "black box" and a visual method are employed to facilitate the publishing of the models as Web services. For the latter, model integration based on the geospatial workflow and semantic supported marching method is introduced. Under this framework, model sharing and integration is applied for developing the Pearl River Delta water environment monitoring system. The results show that the framework can facilitate model sharing and model integration for model publishers and model users.

  10. Model-based Engineering for the Integration of Manufacturing Systems with Advanced Analytics


    Lechevalier , David; Narayanan , Anantha; Rachuri , Sudarsan; Foufou , Sebti; Lee , Y Tina


    Part 3: Interoperability and Systems Integration; International audience; To employ data analytics effectively and efficiently on manufacturing systems, engineers and data scientists need to collaborate closely to bring their domain knowledge together. In this paper, we introduce a domain-specific modeling approach to integrate a manufacturing system model with advanced analytics, in particular neural networks, to model predictions. Our approach combines a set of meta-models and transformatio...

  11. Model-Based Data Integration and Process Standardization Techniques for Fault Management: A Feasibility Study (United States)

    Haste, Deepak; Ghoshal, Sudipto; Johnson, Stephen B.; Moore, Craig


    This paper describes the theory and considerations in the application of model-based techniques to assimilate information from disjoint knowledge sources for performing NASA's Fault Management (FM)-related activities using the TEAMS® toolset. FM consists of the operational mitigation of existing and impending spacecraft failures. NASA's FM directives have both design-phase and operational-phase goals. This paper highlights recent studies by QSI and DST of the capabilities required in the TEAMS® toolset for conducting FM activities with the aim of reducing operating costs, increasing autonomy, and conforming to time schedules. These studies use and extend the analytic capabilities of QSI's TEAMS® toolset to conduct a range of FM activities within a centralized platform.

  12. Model-based integration and testing : bridging the gap between academic theory and industrial practice

    NARCIS (Netherlands)

    Braspenning, N.C.W.M.


    For manufacturers of high-tech multi-disciplinary systems such as semiconductor equipment, the effort required for integration and system testing is ever increasing, while customers demand a shorter time-to-market.This book describes how executable models can replace unavailable component

  13. Evaluation Of Model Based Systems Engineering Processes For Integration Into Rapid Acquisition Programs (United States)


    for the required simulation allowed the MK6LE project to avoid the risk of having lower level model components not integrating together. The initial...that programs that applied MBSE at the lower levels, in particular the MK54 Torpedo program, expressed regrets of limiting the re-architecture to the

  14. A Model-Based Methodology for Integrated Design and Operation of Reactive Distillation Processes

    DEFF Research Database (Denmark)

    Mansouri, Seyed Soheil; Sales-Cruz, Mauricio; Huusom, Jakob Kjøbsted


    and resolved. A new approach isto tackle process intensification and controllability issues in an integrated manner, in the early stages of process design. This integrated and simultaneous synthesis approach provides optimal operation and moreefficient control of complex intensified systems that suffice...... calculation of reactive bubble points. For an energy-efficient design, the driving-forc eapproach (to determine the optimal feed location) for a reactive system has been employed. For both thereactive McCabe-Thiele and driving force method, vapor-liquid equilibrium data are based on elements. Thereactive...... system of compounds (methanol, isobutene and MTBE) to a binary system ofelements (elements A and B). For a binary element system, a simple reactive McCabe-Thiele-type method (to determine the number of reactive stages) has been used. The reactive equilibrium curve is constructed through sequential...

  15. [Psychotherapy of patients with brain lesions: an integrative model based on neuropsychological and psychodynamic perspectives]. (United States)

    Ouss-Ryngaert, Lisa


    Our model of psychotherapy for patients with brain lesions is based on an integrative approach of psychobehavioral symptoms, especially from the neuropsychological and psychodynamic perspectives. Adjustment of technical modalities and aims of psychoanalytical therapy is required for these patients. The analysis of the influence of cognitive disorders on transference and contre-transference plays a major role, including the role of procedural processes in changes in the intersubjective relationship between the patient and the therapist. Two vignettes are presented to illustrate our model, which respects the integrity of the cognitive and psychodynamic approaches and can be implemented by only one therapist, using alternatively each lecture, or by a working team bringing to light the different aspects of the same symptom.

  16. Complex Behavior in an Integrate-and-Fire Neuron Model Based on Small World Networks

    International Nuclear Information System (INIS)

    Lin Min; Chen Tianlun


    Based on our previously pulse-coupled integrate-and-fire neuron model in small world networks, we investigate the complex behavior of electroencephalographic (EEG)-like activities produced by such a model. We find EEG-like activities have obvious chaotic characteristics. We also analyze the complex behaviors of EEG-like signals, such as spectral analysis, reconstruction of the phase space, the correlation dimension, and so on.

  17. Integrated Experimental and Model-based Analysis Reveals the Spatial Aspects of EGFR Activation Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Shankaran, Harish; Zhang, Yi; Chrisler, William B.; Ewald, Jonathan A.; Wiley, H. S.; Resat, Haluk


    The epidermal growth factor receptor (EGFR) belongs to the ErbB family of receptor tyrosine kinases, and controls a diverse set of cellular responses relevant to development and tumorigenesis. ErbB activation is a complex process involving receptor-ligand binding, receptor dimerization, phosphorylation, and trafficking (internalization, recycling and degradation), which together dictate the spatio-temporal distribution of active receptors within the cell. The ability to predict this distribution, and elucidation of the factors regulating it, would help to establish a mechanistic link between ErbB expression levels and the cellular response. Towards this end, we constructed mathematical models for deconvolving the contributions of receptor dimerization and phosphorylation to EGFR activation, and to examine the dependence of these processes on sub-cellular location. We collected experimental datasets for EGFR activation dynamics in human mammary epithelial cells, with the specific goal of model parameterization, and used the data to estimate parameters for several alternate models. Model-based analysis indicated that: 1) signal termination via receptor dephosphorylation in late endosomes, prior to degradation, is an important component of the response, 2) less than 40% of the receptors in the cell are phosphorylated at any given time, even at saturating ligand doses, and 3) receptor dephosphorylation rates at the cell surface and early endosomes are comparable. We validated the last finding by measuring EGFR dephosphorylation rates at various times following ligand addition both in whole cells, and in endosomes using ELISAs and fluorescent imaging. Overall, our results provide important information on how EGFR phosphorylation levels are regulated within cells. Further, the mathematical model described here can be extended to determine receptor dimer abundances in cells co-expressing various levels of ErbB receptors. This study demonstrates that an iterative cycle of

  18. Quantitative geological modeling based on probabilistic integration of geological and geophysical data

    DEFF Research Database (Denmark)

    Gulbrandsen, Mats Lundh

    In order to obtain an adequate geological model of any kind, proper integration of geophysical data, borehole logs and geological expert knowledge is important. Geophysical data provide indirect information about geology, borehole logs provide sparse point wise direct information about geology...... entitled Smart Interpretation is developed. This semi-automatic method learns the relation between a set of data attributes extracted from deterministically inverted airborne electromagnetic data and a set of interpretations of a geological layer that is manually picked by a geological expert...

  19. Gaps Analysis of Integrating Product Design, Manufacturing, and Quality Data in The Supply Chain Using Model-Based Definition. (United States)

    Trainer, Asa; Hedberg, Thomas; Feeney, Allison Barnard; Fischer, Kevin; Rosche, Phil


    MBE vision. Finally, it also seeks to explore the interaction between CAD and CMM processes and determine if the concept of feedback from CAM and CMM back to CAD is feasible. The main goal of our study is to test the hypothesis that model-based-data interoperability from CAD-to-CAM and CAD-to-CMM is feasible through standards-based integration. This paper presents several barriers to model-based-data interoperability. Overall, the project team demonstrated the exchange of product definition data between CAD, CAM, and CMM systems using standards-based methods. While gaps in standards coverage were identified, the gaps should not stop industry's progress toward MBE. The results of our study provide evidence in support of an open-standards method to model-based-data interoperability, which would provide maximum value and impact to industry.

  20. Model-based sensorimotor integration for multi-joint control: development of a virtual arm model. (United States)

    Song, D; Lan, N; Loeb, G E; Gordon, J


    An integrated, sensorimotor virtual arm (VA) model has been developed and validated for simulation studies of control of human arm movements. Realistic anatomical features of shoulder, elbow and forearm joints were captured with a graphic modeling environment, SIMM. The model included 15 musculotendon elements acting at the shoulder, elbow and forearm. Muscle actions on joints were evaluated by SIMM generated moment arms that were matched to experimentally measured profiles. The Virtual Muscle (VM) model contained appropriate admixture of slow and fast twitch fibers with realistic physiological properties for force production. A realistic spindle model was embedded in each VM with inputs of fascicle length, gamma static (gamma(stat)) and dynamic (gamma(dyn)) controls and outputs of primary (I(a)) and secondary (II) afferents. A piecewise linear model of Golgi Tendon Organ (GTO) represented the ensemble sampling (I(b)) of the total muscle force at the tendon. All model components were integrated into a Simulink block using a special software tool. The complete VA model was validated with open-loop simulation at discrete hand positions within the full range of alpha and gamma drives to extrafusal and intrafusal muscle fibers. The model behaviors were consistent with a wide variety of physiological phenomena. Spindle afferents were effectively modulated by fusimotor drives and hand positions of the arm. These simulations validated the VA model as a computational tool for studying arm movement control. The VA model is available to researchers at website .

  1. Model-Based Integrated Process Design and Controller Design of Chemical Processes

    DEFF Research Database (Denmark)

    Abd Hamid, Mohd Kamaruddin Bin

    that is typically formulated as a mathematical programming (optimization with constraints) problem is solved by the so-called reverse approach by decomposing it into four sequential hierarchical sub-problems: (i) pre-analysis, (ii) design analysis, (iii) controller design analysis, and (iv) final selection......This thesis describes the development and application of a new systematic modelbased methodology for performing integrated process design and controller design (IPDC) of chemical processes. The new methodology is simple to apply, easy to visualize and efficient to solve. Here, the IPDC problem...... are ordered according to the defined performance criteria (objective function). The final selected design is then verified through rigorous simulation. In the pre-analysis sub-problem, the concepts of attainable region and driving force are used to locate the optimal process-controller design solution...

  2. Model-based Integration of Past & Future in TimeTravel

    DEFF Research Database (Denmark)

    Khalefa, Mohamed E.; Fischer, Ulrike; Pedersen, Torben Bach


    We demonstrate TimeTravel, an efficient DBMS system for seamless integrated querying of past and (forecasted) future values of time series, allowing the user to view past and future values as one joint time series. This functionality is important for advanced application domain like energy....... The main idea is to compactly represent time series as models. By using models, the TimeTravel system answers queries approximately on past and future data with error guarantees (absolute error and confidence) one order of magnitude faster than when accessing the time series directly. In addition...... it to answer approximate and exact queries. TimeTravel is implemented into PostgreSQL, thus achieving complete user transparency at the query level. In the demo, we show the easy building of a hierarchical model index for a real-world time series and the effect of varying the error guarantees on the speed up...

  3. A Data-Driven, Integrated Flare Model Based on Self-Organized Criticality (United States)

    Dimitropoulou, M.; Isliker, H.; Vlahos, L.; Georgoulis, M.


    We interpret solar flares as events originating in solar active regions having reached the self-organized critical state, by alternatively using two versions of an "integrated flare model" - one static and one dynamic. In both versions the initial conditions are derived from observations aiming to investigate whether well-known scaling laws observed in the distribution functions of characteristic flare parameters are reproduced after the self-organized critical state has been reached. In the static model, we first apply a nonlinear force-free extrapolation that reconstructs the three-dimensional magnetic fields from two-dimensional vector magnetograms. We then locate magnetic discontinuities exceeding a threshold in the Laplacian of the magnetic field. These discontinuities are relaxed in local diffusion events, implemented in the form of cellular-automaton evolution rules. Subsequent loading and relaxation steps lead the system to self-organized criticality, after which the statistical properties of the simulated events are examined. In the dynamic version we deploy an enhanced driving mechanism, which utilizes the observed evolution of active regions, making use of sequential vector magnetograms. We first apply the static cellular automaton model to consecutive solar vector magnetograms until the self-organized critical state is reached. We then evolve the magnetic field inbetween these processed snapshots through spline interpolation, acting as a natural driver in the dynamic model. The identification of magnetically unstable sites as well as their relaxation follow the same rules as in the static model after each interpolation step. Subsequent interpolation/driving and relaxation steps cover all transitions until the end of the sequence. Physical requirements, such as the divergence-free condition for the magnetic field vector, are approximately satisfied in both versions of the model. We obtain robust power laws in the distribution functions of the modelled

  4. Integrated Model-Based Decisions for Water, Energy and Food Nexus (United States)

    Zhang, X.; Vesselinov, V. V.


    Energy, water and food are critical resources for sustaining social development and human lives; human beings cannot survive without any one of them. Energy crises, water shortages and food security are crucial worldwide problems. The nexus of energy, water and food has received more and more attention in the past decade. Energy, water and food are closely interrelated; water is required in energy development such as electricity generation; energy is indispensable for collecting, treating, and transporting water; both energy and water are crucial inputs for food production. Changes of either of them can lead to substantial impacts on other two resources, and vice versa. Effective decisions should be based on thorough research efforts for better understanding of their complex nexus. Rapid increase of population has significantly intensified the pressures on energy, water and food. Addressing and quantifying their interactive relationships are important for making robust and cost-effective strategies for managing the three resources simultaneously. In addition, greenhouse gases (GHGs) are emitted in energy, water, food production, consequently making contributions to growing climate change. Reflecting environmental impacts of GHGs is also desired (especially, on the quality and quantity of fresh water resources). Thus, a socio-economic model is developed in this study to quantitatively address the complex connections among energy, water and food production. A synthetic problem is proposed to demonstrate the model's applicability and feasibility. Preliminary results related to integrated decisions on energy supply management, water use planning, electricity generation planning, energy facility capacity expansion, food production, and associated GHG emission control are generated for providing cost-effective supports for decision makers.

  5. Report of a national neurosurgical emergency teleconsulting system.

    LENUS (Irish Health Repository)

    Gray, W P


    OBJECTIVE: The goal was to develop a low-cost, national, neurosurgical emergency teleconsulting system that is independent of vendor computed tomographic (CT) or magnetic resonance imaging (MRI) scanner type. METHODS: Charge-coupled device scanners are used to digitize hard copies of CT and MRI scans. An enhanced optical density range is achieved by using an algorithm to fuse data from multiple exposures at different integration periods. The system is based on personal computers using Microsoft Windows 3.11. Data are transmitted on a wide-area network at 128 kilobits\\/s, over Integrated Systems Digital Network lines. The network connects both neurosurgical departments in Ireland to all major hospitals with CT\\/MRI scanners. RESULTS: The scanner optical density is 0.05 to 3.0, with 2.24 to 2.5 line pairs\\/mm. Five-megabyte images are transmitted uncompressed in 6 minutes. To date, more than 750 CT and MRI scans have been transmitted. The system is completely automated, and operator acceptance has been very high. Images are automatically stored and displayed at the receiving workstation, where the images can be viewed and manipulated on-screen. This system has significantly enhanced acute neurosurgical patient care. CONCLUSION: The system is cost effective and simple to use, has gained widespread physician acceptance, and delivers an image quality superior to that of many commercially available systems.

  6. Dynamic data-driven integrated flare model based on self-organized criticality (United States)

    Dimitropoulou, M.; Isliker, H.; Vlahos, L.; Georgoulis, M. K.


    Context. We interpret solar flares as events originating in active regions that have reached the self-organized critical state. We describe them with a dynamic integrated flare model whose initial conditions and driving mechanism are derived from observations. Aims: We investigate whether well-known scaling laws observed in the distribution functions of characteristic flare parameters are reproduced after the self-organized critical state has been reached. Methods: To investigate whether the distribution functions of total energy, peak energy, and event duration follow the expected scaling laws, we first applied the previously reported static cellular automaton model to a time series of seven solar vector magnetograms of the NOAA active region 8210 recorded by the Imaging Vector Magnetograph on May 1 1998 between 18:59 UT and 23:16 UT until the self-organized critical state was reached. We then evolved the magnetic field between these processed snapshots through spline interpolation, mimicking a natural driver in our dynamic model. We identified magnetic discontinuities that exceeded a threshold in the Laplacian of the magnetic field after each interpolation step. These discontinuities were relaxed in local diffusion events, implemented in the form of cellular automaton evolution rules. Subsequent interpolation and relaxation steps covered all transitions until the end of the processed magnetograms' sequence. We additionally advanced each magnetic configuration that has reached the self-organized critical state (SOC configuration) by the static model until 50 more flares were triggered, applied the dynamic model again to the new sequence, and repeated the same process sufficiently often to generate adequate statistics. Physical requirements, such as the divergence-free condition for the magnetic field, were approximately imposed. Results: We obtain robust power laws in the distribution functions of the modeled flaring events with scaling indices that agree well

  7. Neurosurgical Resident Training in Germany. (United States)

    Stienen, Martin N; Gempt, Jens; Gautschi, Oliver P; Demetriades, Andreas K; Netuka, David; Kuhlen, Dominique E; Schaller, Karl; Ringel, Florian


    Introduction  Efficient neurosurgical training is of paramount importance to provide continuing high-quality medical care to patients. In this era of law-enforced working hour restrictions, however, maintaining high-quality training can be a challenge and requires some restructuring. We evaluated the current status of resident training in Germany. Methods  An electronic survey was sent to European neurosurgical trainees between June 2014 and March 2015. The responses of German trainees were compared with those of trainees from other European countries. Logistic regression analysis was performed to assess the effect size of the relationship between a trainee being from Germany and the outcome (e.g., satisfaction, working time). Results  Of 532 responses, 95 were from German trainees (17.8%). In a multivariate analysis corrected for baseline group differences, German trainees were 29% as likely as non-German trainees to be satisfied with clinical lectures given at their teaching facility (odds ratio [OR]: 0.29; 95% confidence interval [CI]: 0.18-0.49; p  hours as requested from the European Working Time Directive 2003/88/EC, and in an international comparison, German trainees were twice as likely to work > 50 hours per week (OR: 2.13; 95% CI, 1.25-3.61; p  = 0.005). This working time, however, is less spent in the operating suite (OR: 0.26; 95% CI, 0.11-0.59; p  = 0.001) and more doing administrative work (OR: 1.83; 95% CI, 1.13-2.96; p  = 0.015). Conclusion  Some theoretical and practical aspects of neurosurgical training are superior, but a considerable proportion of relevant aspects are inferior in Germany compared with other European countries. The present analyses provide the opportunity for a critical review of the local conditions in German training facilities. Georg Thieme Verlag KG Stuttgart · New York.

  8. Merging pathways: music therapy in neurosurgical rehabilitation. (United States)

    Gilbertson, S; Ischebeck, W


    Relatively few departments of Music Therapy are found within neurosurgical rehabilitation clinics. In institutions where these departments exist, music therapy has become an integral part of multi-professional treatment and research activities (Gilbertson 1999). The diverse intervention strategies in Music Therapy focus upon auditory, motor, visual, cognitive and affective processing which are all involved in receptive and expressive musical behaviour and which affect related non-musical behaviour. A clear differentiation is made between primary and adjunct therapy roles. The related fields of neuromusicology, neuroanatomy, neuropsychology, music psychology and humanistic psychology are primary sources in the development of models of clinical application (Hodges 1996). Our main interests are focussed on the following issues and areas of clinical application: The initialisation of contact with patients in vegetative status Communicative interaction with patients who can not (initially) use verbal communication (aphasic disorders) Temporal motor organisation with patients with sensomotor disorders Cognitive organisation and mnemonic framework with patients with neuropsychological functional disorders (concentration, memory, perception) Treatment of spatial perception disorders (neglect) Enhancing personal and social integration following individual isolation, social withdrawal. These topics will be discussed and highlighted with clinical examples.

  9. Metabolic Model-Based Integration of Microbiome Taxonomic and Metabolomic Profiles Elucidates Mechanistic Links between Ecological and Metabolic Variation

    Energy Technology Data Exchange (ETDEWEB)

    Noecker, Cecilia; Eng, Alexander; Srinivasan, Sujatha; Theriot, Casey M.; Young, Vincent B.; Jansson, Janet K.; Fredricks, David N.; Borenstein, Elhanan; Sanchez, Laura M.


    health and disease.

    IMPORTANCEStudies characterizing both the taxonomic composition and metabolic profile of various microbial communities are becoming increasingly common, yet new computational methods are needed to integrate and interpret these data in terms of known biological mechanisms. Here, we introduce an analytical framework to link species composition and metabolite measurements, using a simple model to predict the effects of community ecology on metabolite concentrations and evaluating whether these predictions agree with measured metabolomic profiles. We find that a surprisingly large proportion of metabolite variation in the vaginal microbiome can be predicted based on species composition (including dramatic shifts associated with disease), identify putative mechanisms underlying these predictions, and evaluate the roles of individual bacterial species and genes. Analysis of gut microbiome data using this framework recovers similar community metabolic trends. This framework lays the foundation for model-based multi-omic integrative studies, ultimately improving our understanding of microbial community metabolism.

  10. Employing Model-Based Reasoning in Interdisciplinary Research Teams: Evidence-Based Practices for Integrating Knowledge Across Systems (United States)

    Pennington, D. D.; Vincent, S.


    The NSF-funded project "Employing Model-Based Reasoning in Socio-Environmental Synthesis (EMBeRS)" has developed a generic model for exchanging knowledge across disciplines that is based on findings from the cognitive, learning, social, and organizational sciences addressing teamwork in complex problem solving situations. Two ten-day summer workshops for PhD students from large, NSF-funded interdisciplinary projects working on a variety of water issues were conducted in 2016 and 2017, testing the model by collecting a variety of data, including surveys, interviews, audio/video recordings, material artifacts and documents, and photographs. This presentation will introduce the EMBeRS model, the design of workshop activities based on the model, and results from surveys and interviews with the participating students. Findings suggest that this approach is very effective for developing a shared, integrated research vision across disciplines, compared with activities typically provided by most large research projects, and that students believe the skills developed in the EMBeRS workshops are unique and highly desireable.

  11. Handling equipment Selection in open pit mines by using an integrated model based on group decision making

    Directory of Open Access Journals (Sweden)

    Abdolreza Yazdani-Chamzini


    Full Text Available Process of handling equipment selection is one of the most important and basic parts in the project planning, particularly mining projects due to holding a high charge of the total project's cost. Different criteria impact on the handling equipment selection, while these criteria often are in conflicting with each other. Therefore, the process of handling equipment selection is a complex and multi criteria decision making problem. There are a variety of methods for selecting the most appropriate equipment among a set of alternatives. Likewise, according to the sophisticated structure of the problem, imprecise data, less of information, and inherent uncertainty, the usage of the fuzzy sets can be useful. In this study a new integrated model based on fuzzy analytic hierarchy process (FAHP and fuzzy technique for order preference by similarity to ideal solution (FTOPSIS is proposed, which uses group decision making to reduce individual errors. In order to calculate the weights of the evaluation criteria, FAHP is utilized in the process of handling equipment selection, and then these weights are inserted to the FTOPSIS computations to select the most appropriate handling system among a pool of alternatives. The results of this study demonstrate the potential application and effectiveness of the proposed model, which can be applied to different types of sophisticated problems in real problems.

  12. Novel CNS drug discovery and development approach: model-based integration to predict neuro-pharmacokinetics and pharmacodynamics. (United States)

    de Lange, Elizabeth C M; van den Brink, Willem; Yamamoto, Yumi; de Witte, Wilhelmus E A; Wong, Yin Cheong


    CNS drug development has been hampered by inadequate consideration of CNS pharmacokinetic (PK), pharmacodynamics (PD) and disease complexity (reductionist approach). Improvement is required via integrative model-based approaches. Areas covered: The authors summarize factors that have played a role in the high attrition rate of CNS compounds. Recent advances in CNS research and drug discovery are presented, especially with regard to assessment of relevant neuro-PK parameters. Suggestions for further improvements are also discussed. Expert opinion: Understanding time- and condition dependent interrelationships between neuro-PK and neuro-PD processes is key to predictions in different conditions. As a first screen, it is suggested to use in silico/in vitro derived molecular properties of candidate compounds and predict concentration-time profiles of compounds in multiple compartments of the human CNS, using time-course based physiology-based (PB) PK models. Then, for selected compounds, one can include in vitro drug-target binding kinetics to predict target occupancy (TO)-time profiles in humans. This will improve neuro-PD prediction. Furthermore, a pharmaco-omics approach is suggested, providing multilevel and paralleled data on systems processes from individuals in a systems-wide manner. Thus, clinical trials will be better informed, using fewer animals, while also, needing fewer individuals and samples per individual for proof of concept in humans.

  13. Coagulation management in patients undergoing neurosurgical procedures. (United States)

    Robba, Chiara; Bertuetti, Rita; Rasulo, Frank; Bertuccio, Alessando; Matta, Basil


    Management of coagulation in neurosurgical procedures is challenging. In this contest, it is imperative to avoid further intracranial bleeding. Perioperative bleeding can be associated with a number of factors, including anticoagulant drugs and coagulation status but is also linked to the characteristic and the site of the intracranial disorder. The aim of this review will be to focus primarily on the new evidence regarding the management of coagulation in patients undergoing craniotomy for neurosurgical procedures. Antihemostatic and anticoagulant drugs have shown to be associated with perioperative bleeding. On the other hand, an increased risk of venous thromboembolism and hypercoagulative state after elective and emergency neurosurgery, in particular after brain tumor surgery, has been described in several patients. To balance the risk between thrombosis and bleeding, it is important to be familiar with the perioperative changes in coagulation and with the recent management guidelines for anticoagulated patients undergoing neurosurgical procedures, in particular for those taking new direct anticoagulants. We have considered the current clinical trials and literature regarding both safety and efficacy of deep venous thrombosis prophylaxis in the neurosurgical population. These were mainly trials concerning both elective surgical and intensive care patients with a poor grade intracranial bleed or multiple traumas with an associated severe traumatic brain injury (TBI). Coagulation management remains a major issue in patients undergoing neurosurgical procedures. However, in this field of research, literature quality is poor and further studies are necessary to identify the best strategies to minimize risks in this group of patients.

  14. Disorders of water homeostasis in neurosurgical patients.

    LENUS (Irish Health Repository)

    Hannon, Mark J


    Context: Disorders of water balance are common in neurosurgical patients and usually manifest as hypo- or hypernatremia. They are most commonly seen after subarachnoid hemorrhage, traumatic brain injury, with intracranial tumors, and after pituitary surgery. Setting: We reviewed the experience of endocrine evaluation and management of disorders of salt and water balance in a large cohort of inpatients attending the national neurosciences referral centre in Dublin, Ireland, and compared this experience with findings from other studies. Patients: The study group included unselected neurosurgical patients admitted to our centre and requiring endocrine evaluation. Interventions: We conducted investigations to determine the underlying mechanistic basis for disorders of salt and water balance in neurosurgical patients and treatment to restore normal metabolism. Main Outcome Measures: Morbidity and mortality associated with deranged salt and water balance were measured. Results: The underlying pathophysiology of disordered water balance in neurosurgical patients is complex and varied and dictates the optimal therapeutic approach. Conclusions: A systematic and well-informed approach is needed to properly diagnose and manage disorders of salt and water balance in neurosurgical patients.

  15. Neurosurgical implications of Carney complex. (United States)

    Watson, J C; Stratakis, C A; Bryant-Greenwood, P K; Koch, C A; Kirschner, L S; Nguyen, T; Carney, J A; Oldfield, E H


    The authors present their neurosurgical experience with Carney complex. Carney complex, characterized by spotty skin pigmentation, cardiac myxomas, primary pigmented nodular adrenocortical disease, pituitary tumors, and nerve sheath tumors (NSTs), is a recently described, rare, autosomal-dominant familial syndrome that is relatively unknown to neurosurgeons. Neurosurgery is required to treat pituitary adenomas and a rare NST, the psammomatous melanotic schwannoma (PMS), in patients with Carney complex. Cushing's syndrome, a common component of the complex, is caused by primary pigmented nodular adrenocortical disease and is not secondary to an adrenocorticotropic hormone-secreting pituitary adenoma. The authors reviewed 14 cases of Carney complex, five from the literature and nine from their own experience. Of the 14 pituitary adenomas recognized in association with Carney complex, 12 developed growth hormone (GH) hypersecretion (producing gigantism in two patients and acromegaly in 10), and results of immunohistochemical studies in one of the other two were positive for GH. The association of PMSs with Carney complex was established in 1990. Of the reported tumors, 28% were associated with spinal nerve sheaths. The spinal tumors occurred in adults (mean age 32 years, range 18-49 years) who presented with pain and radiculopathy. These NSTs may be malignant (10%) and, as with the cardiac myxomas, are associated with significant rates of morbidity and mortality. Because of the surgical comorbidity associated with cardiac myxoma and/or Cushing's syndrome, recognition of Carney complex has important implications for perisurgical patient management and family screening. Study of the genetics of Carney complex and of the biological abnormalities associated with the tumors may provide insight into the general pathobiological abnormalities associated with the tumors may provide insight into the general pathobiological features of pituitary adenomas and NSTs.

  16. The neurosurgical treatment of neuropathic facial pain. (United States)

    Brown, Jeffrey A


    This article reviews the definition, etiology and evaluation, and medical and neurosurgical treatment of neuropathic facial pain. A neuropathic origin for facial pain should be considered when evaluating a patient for rhinologic surgery because of complaints of facial pain. Neuropathic facial pain is caused by vascular compression of the trigeminal nerve in the prepontine cistern and is characterized by an intermittent prickling or stabbing component or a constant burning, searing pain. Medical treatment consists of anticonvulsant medication. Neurosurgical treatment may require microvascular decompression of the trigeminal nerve. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Neurosurgical Interventions for Occipital Encephalocele (United States)

    Rehman, Lal; Farooq, Ghulam; Bukhari, Irum


    neurosurgery in the world as well as in Pakistan. Modern neuroimaging, neurosurgical techniques, and neonatal neurological intensive care have greatly improved morbidity and mortality in the care of encephalocele. PMID:29682014

  18. The "proactive" model of learning: Integrative framework for model-free and model-based reinforcement learning utilizing the associative learning-based proactive brain concept. (United States)

    Zsuga, Judit; Biro, Klara; Papp, Csaba; Tajti, Gabor; Gesztelyi, Rudolf


    Reinforcement learning (RL) is a powerful concept underlying forms of associative learning governed by the use of a scalar reward signal, with learning taking place if expectations are violated. RL may be assessed using model-based and model-free approaches. Model-based reinforcement learning involves the amygdala, the hippocampus, and the orbitofrontal cortex (OFC). The model-free system involves the pedunculopontine-tegmental nucleus (PPTgN), the ventral tegmental area (VTA) and the ventral striatum (VS). Based on the functional connectivity of VS, model-free and model based RL systems center on the VS that by integrating model-free signals (received as reward prediction error) and model-based reward related input computes value. Using the concept of reinforcement learning agent we propose that the VS serves as the value function component of the RL agent. Regarding the model utilized for model-based computations we turned to the proactive brain concept, which offers an ubiquitous function for the default network based on its great functional overlap with contextual associative areas. Hence, by means of the default network the brain continuously organizes its environment into context frames enabling the formulation of analogy-based association that are turned into predictions of what to expect. The OFC integrates reward-related information into context frames upon computing reward expectation by compiling stimulus-reward and context-reward information offered by the amygdala and hippocampus, respectively. Furthermore we suggest that the integration of model-based expectations regarding reward into the value signal is further supported by the efferent of the OFC that reach structures canonical for model-free learning (e.g., the PPTgN, VTA, and VS). (c) 2016 APA, all rights reserved).

  19. Pattern of Neurosurgical Procedures in Ethiopia: Experience from ...

    African Journals Online (AJOL)

    Background: In Ethiopia, the number of practicing neurosurgeons is very few and the pattern of neurosurgical diseases and operations is not well known.This study was aimed to define the patterns of neurosurgical diseases and the operative procedures commonly seen at two main neurosurgical hospitals in Ethiopia.

  20. Congenital malformations in paediatric and neurosurgical practices ...

    African Journals Online (AJOL)

    Congenital malformations in paediatric and neurosurgical practices: problems and pattern (A preliminary report) ... Open Access DOWNLOAD FULL TEXT ... over a 5-year period (1998 to 2002) with congenital anomalies to the Paediatric Surgery and Neurosurgery units of the University Teaching Hospital, Ilorin, Nigeria.

  1. Spectrum of neurosurgical complications following medical tourism ...

    African Journals Online (AJOL)

    Background and objectives: The cost of medical care and availability of resources (human and facilities) which differs from nation to nation are amongst others, factors driving medical tourism (MT) despite its potential drawbacks. The aim of the study was to analyse all patients that presented with neurosurgical complications ...

  2. Neurosurgical Procedures in Jehovah's Witnesses: The Tema ...

    African Journals Online (AJOL)

    BACKGROUND: On account of religious reasons, Jehovah Witnesses do not accept blood or blood products; occasionally, they accept reinfusion of autologous blood via a cell saver during surgery. OBJECTIVE: The aim of this study was to document the demographics of Jehovah Witnesses undergoing neurosurgical ...

  3. Neurological and neurosurgical manifestations of human ...

    African Journals Online (AJOL)

    Neurological and neurosurgical manifestations of human immunodeficiency virus (HIV) infection in Mrica. Adelola Adeloye MS FRCS FRCP. Professor. Department of Surgery, College of Medicine. Blantyre, Malawi. Introduction. AIDS was first recognised in the United States of . America in the late 1970s among homosexual ...

  4. Patterns in neurosurgical adverse events: endovascular neurosurgery. (United States)

    Wong, Judith M; Ziewacz, John E; Panchmatia, Jaykar R; Bader, Angela M; Pandey, Aditya S; Thompson, B Gregory; Frerichs, Kai; Gawande, Atul A


    As part of a project to devise evidence-based safety interventions for specialty surgery, the authors sought to review current evidence in endovascular neurosurgery concerning the frequency of adverse events in practice, their patterns, and current methods of reducing the occurrence of these events. This review represents part of a series of papers written to consolidate information about these events and preventive measures as part of an ongoing effort to ascertain the utility of devising system-wide policies and safety tools to improve neurosurgical practice. Based on a review of the literature, thromboembolic events appeared to be the most common adverse events in endovascular neurosurgery, with a reported incidence ranging from 2% to 61% depending on aneurysm rupture status and mode of detection of the event. Intraprocedural and periprocedural prevention and rescue regimens are advocated to minimize this risk; however, evidence on the optimal use of anticoagulant and antithrombotic agents is limited. Furthermore, it is unknown what proportion of eligible patients receive any prophylactic treatment. Groin-site hematoma is the most common access-related complication. Data from the cardiac literature indicate an overall incidence of 9% to 32%, but data specific to neuroendovascular therapy are scant. Manual compression, compression adjuncts, and closure devices are used with varying rates of success, but no standardized protocols have been tested on a broad scale. Contrast-induced nephropathy is one of the more common causes of hospital-acquired renal insufficiency, with an incidence of 30% in high-risk patients after contrast administration. Evidence from medical fields supports the use of various preventive strategies. Intraprocedural vessel rupture is infrequent, with the reported incidence ranging from 1% to 9%, but it is potentially devastating. Improvements in device technology combined with proper endovascular technique play an important role in reducing

  5. A microcontroller-based simulation of dural venous sinus injury for neurosurgical training. (United States)

    Cleary, Daniel R; Siler, Dominic A; Whitney, Nathaniel; Selden, Nathan R


    OBJECTIVE Surgical simulation has the potential to supplement and enhance traditional resident training. However, the high cost of equipment and limited number of available scenarios have inhibited wider integration of simulation in neurosurgical education. In this study the authors provide initial validation of a novel, low-cost simulation platform that recreates the stress of surgery using a combination of hands-on, model-based, and computer elements. Trainee skill was quantified using multiple time and performance measures. The simulation was initially validated using trainees at the start of their intern year. METHODS The simulation recreates intraoperative superior sagittal sinus injury complicated by air embolism. The simulator model consists of 2 components: a reusable base and a disposable craniotomy pack. The simulator software is flexible and modular to allow adjustments in difficulty or the creation of entirely new clinical scenarios. The reusable simulator base incorporates a powerful microcomputer and multiple sensors and actuators to provide continuous feedback to the software controller, which in turn adjusts both the screen output and physical elements of the model. The disposable craniotomy pack incorporates 3D-printed sections of model skull and brain, as well as artificial dura that incorporates a model sagittal sinus. RESULTS Twelve participants at the 2015 Western Region Society of Neurological Surgeons postgraduate year 1 resident course ("boot camp") provided informed consent and enrolled in a study testing the prototype device. Each trainee was required to successfully create a bilateral parasagittal craniotomy, repair a dural sinus tear, and recognize and correct an air embolus. Participant stress was measured using a heart rate wrist monitor. After participation, each resident completed a 13-question categorical survey. CONCLUSIONS All trainee participants experienced tachycardia during the simulation, although the point in the simulation

  6. Massive cerebellar infarction: a neurosurgical approach

    Directory of Open Access Journals (Sweden)

    Salazar Luis Rafael Moscote


    Full Text Available Cerebellar infarction is a challenge for the neurosurgeon. The rapid recognition will crucial to avoid devastating consequences. The massive cerebellar infarction has pseudotumoral behavior, should affect at least one third of the volume of the cerebellum. The irrigation of the cerebellum presents anatomical diversity, favoring the appearance of atypical infarcts. The neurosurgical management is critical for massive cerebellar infarction. We present a review of the literature.

  7. Virtual Reality and Simulation in Neurosurgical Training. (United States)

    Bernardo, Antonio


    Recent biotechnological advances, including three-dimensional microscopy and endoscopy, virtual reality, surgical simulation, surgical robotics, and advanced neuroimaging, have continued to mold the surgeon-computer relationship. For developing neurosurgeons, such tools can reduce the learning curve, improve conceptual understanding of complex anatomy, and enhance visuospatial skills. We explore the current and future roles and application of virtual reality and simulation in neurosurgical training. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Rural neurosurgical and spinal laboratory setup. (United States)

    Smith, Adam; Gagliardi, Filippo; Pelzer, Nicholas Robert; Hampton, Jacob; Chau, Anthony Minh Tien; Stewart, Fiona; Mortini, Pietro; Gragnaniello, Cristian


    Increasing focus has been placed on the use of simulation in neurosurgical and spinal surgical training worldwide, with the establishment of many surgical laboratories dedicated to such purpose. So far, the opportunities for hands-on cadaveric training in the areas of neurosurgery and spine surgery remain limited in Australia, owing to various factors, including the abolition of dissection in many medical schools, high maintenance requirements and widespread geographical distribution of surgical trainees. We established a cadaver-based neurosurgical laboratory based at the medical school of the University of New England in Armidale, Australia, which is used by the surgical dissection course for junior surgical trainees offered by the university. We reported our experiences in setting up a neurosurgical research laboratory, and explored the feasibility of establishing a cost-effective anatomical research facility in a rural setting in Australia. We found that Genelyn(TM)-fixed cadavers had limited movements of the head as required for adequate surgical positioning and exposure. Furthermore, we discovered that bodies embalmed via the femoral vein had poorly perfused heads after surgical exposure, and thus decapitation had to be performed unfortunately for our purpose. Cadaver samples and surgical equipment were sourced from various veterinary practices and commercial companies. Using human and animal cadavers, this laboratory provided trainees with hands-on opportunities to improve their surgical skills and neuroanatomical knowledge, as well as develop familiarity with highly specialized surgical equipment. We demonstrated the feasibility of establishing a cost-effective neurosurgical research laboratory in Australia and discussed various aspects of its maintenance.

  9. Vertical integration and market power: A model-based analysis of restructuring in the Korean electricity market

    International Nuclear Information System (INIS)

    Bunn, Derek W.; Martoccia, Maria; Ochoa, Patricia; Kim, Haein; Ahn, Nam-Sung; Yoon, Yong-Beom


    An agent-based simulation model is developed using computational learning to investigate the impact of vertical integration between electricity generators and retailers on market power in a competitive wholesale market setting. It is observed that if partial vertical integration creates some market foreclosure, whether this leads to an increase or decrease in market power is situation specific. A detailed application to the Korean market structure reveals this to be the case. We find that in various cases, whilst vertical integration generally reduces spot prices, it can increase or decrease the market power of other market generators, depending upon the market share and the technology segment of the market, which is integrated, as well as the market concentrations before and after the integration.

  10. Vertical integration and market power. A model-based analysis of restructuring in the Korean electricity market

    Energy Technology Data Exchange (ETDEWEB)

    Bunn, Derek W.; Martoccia, Maria; Ochoa, Patricia [London Business School, London (United Kingdom); Kim, Haein; Ahn, Nam-Sung; Yoon, Yong-Beom [Korean Electric Power Corporation, Seoul (Korea)


    An agent-based simulation model is developed using computational learning to investigate the impact of vertical integration between electricity generators and retailers on market power in a competitive wholesale market setting. It is observed that if partial vertical integration creates some market foreclosure, whether this leads to an increase or decrease in market power is situation specific. A detailed application to the Korean market structure reveals this to be the case. We find that in various cases, whilst vertical integration generally reduces spot prices, it can increase or decrease the market power of other market generators, depending upon the market share and the technology segment of the market, which is integrated, as well as the market concentrations before and after the integration. (author)

  11. Vertical integration and market power: A model-based analysis of restructuring in the Korean electricity market

    Energy Technology Data Exchange (ETDEWEB)

    Bunn, Derek W., E-mail: dbunn@london.ed [London Business School, London (United Kingdom); Martoccia, Maria; Ochoa, Patricia [London Business School, London (United Kingdom); Kim, Haein; Ahn, Nam-Sung; Yoon, Yong-Beom [Korean Electric Power Corporation, Seoul (Korea, Republic of)


    An agent-based simulation model is developed using computational learning to investigate the impact of vertical integration between electricity generators and retailers on market power in a competitive wholesale market setting. It is observed that if partial vertical integration creates some market foreclosure, whether this leads to an increase or decrease in market power is situation specific. A detailed application to the Korean market structure reveals this to be the case. We find that in various cases, whilst vertical integration generally reduces spot prices, it can increase or decrease the market power of other market generators, depending upon the market share and the technology segment of the market, which is integrated, as well as the market concentrations before and after the integration.

  12. Does famotidine induce thrombocytopenia in neurosurgical patients? (United States)

    Ecker, Robert D; Wijdicks, Eelco F M; Wix, Kelly; McClelland, Robyn


    The incidence of thrombocytopenia in neurosurgical patients prescribed famotidine is unknown. Using hospital records of neurosurgery patients treated between July 2001 and July 2002, a retrospective cohort study was performed comparing platelet counts in patients treated with famotidine with a similar group of patients who were not prescribed an H2 antagonist. Patients were excluded if: 1) platelets were less than 150,000 prior to famotidine administration; 2) pre-drug and post-drug platelets were not drawn; 3) they were concurrently taking a potential thrombocytopenic inducing drug; or 4) disseminated intravascular coagulation, thrombocytopenic purpura, or any other confounding hematologic disorder developed. Seventeen of 50 (34%) patients on famotidine developed thrombocytopenia compared with 11 of 98 (11.2%) of those untreated (P = 0.002). In this retrospective study, neurosurgical patients on famotidine developed thrombocytopenia statistically significantly more often than those untreated. Although no clinically significant sequelae developed as a result of the thrombocytopenia, if these findings are confirmed by a prospective study, proton pump inhibitors and sucralfate, with their similar efficacy, may be a better choice for gastrointestinal prophylaxis in neurosurgical patients.

  13. Neurosurgical robotic arm drilling navigation system. (United States)

    Lin, Chung-Chih; Lin, Hsin-Cheng; Lee, Wen-Yo; Lee, Shih-Tseng; Wu, Chieh-Tsai


    The aim of this work was to develop a neurosurgical robotic arm drilling navigation system that provides assistance throughout the complete bone drilling process. The system comprised neurosurgical robotic arm navigation combining robotic and surgical navigation, 3D medical imaging based surgical planning that could identify lesion location and plan the surgical path on 3D images, and automatic bone drilling control that would stop drilling when the bone was to be drilled-through. Three kinds of experiment were designed. The average positioning error deduced from 3D images of the robotic arm was 0.502 ± 0.069 mm. The correlation between automatically and manually planned paths was 0.975. The average distance error between automatically planned paths and risky zones was 0.279 ± 0.401 mm. The drilling auto-stopping algorithm had 0.00% unstopped cases (26.32% in control group 1) and 70.53% non-drilled-through cases (8.42% and 4.21% in control groups 1 and 2). The system may be useful for neurosurgical robotic arm drilling navigation. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Functional magnetic resonance imaging for neurosurgical planning in neurooncology

    International Nuclear Information System (INIS)

    Vlieger, Erik-Jan; Majoie, Charles B.; Heeten, Gerard J. den; Leenstra, Sieger


    Functional magnetic resonance imaging (fMRI) is a non-invasive technique that is widely available and can be used to determine the spatial relationships between tumor tissue and eloquent brain areas. Within certain limits, this functional information can be applied in the field of neurosurgery as a pre-operative mapping tool to minimize damage to eloquent brain areas. In this article, we review the literature on the use of fMRI for neurosurgical planning. The issues addressed are: (1) stimulation paradigms, (2) the influence of tumors on the blood oxygenation level-dependent (BOLD) signal, (3) post-processing the fMRI time course, (4) integration of fMRI results into neuronavigation systems, (5) the accuracy of fMRI and (6) fMRI compared to intra-operative mapping (IOM). (orig.)

  15. Comparative analysis of the influence of creep of concrete composite beams of steel - concrete model based on Volterra integral equation

    Directory of Open Access Journals (Sweden)

    Partov Doncho


    Full Text Available The paper presents analysis of the stress-strain behaviour and deflection changes due to creep in statically determinate composite steel-concrete beam according to EUROCODE 2, ACI209R-92 and Gardner&Lockman models. The mathematical model involves the equation of equilibrium, compatibility and constitutive relationship, i.e. an elastic law for the steel part and an integral-type creep law of Boltzmann - Volterra for the concrete part considering the above mentioned models. On the basis of the theory of viscoelastic body of Maslov-Arutyunian-Trost-Zerna-Bažant for determining the redistribution of stresses in beam section between concrete plate and steel beam with respect to time 't', two independent Volterra integral equations of the second kind have been derived. Numerical method based on linear approximation of the singular kernel function in the integral equation is presented. Example with the model proposed is investigated.

  16. Integrating public demands into model-based design for multifunctional agriculture: An application to intensive dutch dairy landscapes

    NARCIS (Netherlands)

    Parra-López, C.; Groot, J.C.J.; Carmona-Torres, C.; Rossing, W.A.H.


    The contribution of agriculture to the welfare of society is determined by its economic, social and environmental performance. Although theoretical discussions can be found in the literature, few reports exist that integrate the social demand for multifunctional agriculture in the evaluation of the

  17. An interval-valued 2-tuple linguistic group decision-making model based on the Choquet integral operator (United States)

    Liu, Bingsheng; Fu, Meiqing; Zhang, Shuibo; Xue, Bin; Zhou, Qi; Zhang, Shiruo


    The Choquet integral (IL) operator is an effective approach for handling interdependence among decision attributes in complex decision-making problems. However, the fuzzy measures of attributes and attribute sets required by IL are difficult to achieve directly, which limits the application of IL. This paper proposes a new method for determining fuzzy measures of attributes by extending Marichal's concept of entropy for fuzzy measure. To well represent the assessment information, interval-valued 2-tuple linguistic context is utilised to represent information. Then, we propose a Choquet integral operator in an interval-valued 2-tuple linguistic environment, which can effectively handle the correlation between attributes. In addition, we apply these methods to solve multi-attribute group decision-making problems. The feasibility and validity of the proposed operator is demonstrated by comparisons with other models in illustrative example part.

  18. Designing an integrated model based on the indicators Quality and Earned Value for risk management in Information Technology Projects


    TATLARI, Mohammad Reza; KAZEMİPOOR, Hamed


    There are two effective factors on Information Technology (IT) projects risk including quality and earned value so that by controlling these two factors and their increased level in IT projects, the corresponding risk can be decreased. Therefore in present study, an integrated model was designed based on quality and earned value indicators for risk management in IT projects on a new and efficient approach. The proposed algorithm included the steps such as preparing a list of several indicator...

  19. Integrated Sensing and Controls for Coal Gasification - Development of Model-Based Controls for GE's Gasifier and Syngas Cooler

    Energy Technology Data Exchange (ETDEWEB)

    Aditya Kumar


    This report summarizes the achievements and final results of this program. The objective of this program is to develop a comprehensive systems approach to integrated design of sensing and control systems for an Integrated Gasification Combined Cycle (IGCC) plant, using advanced model-based techniques. In particular, this program is focused on the model-based sensing and control system design for the core gasification section of an IGCC plant. The overall approach consists of (i) developing a first-principles physics-based dynamic model of the gasification section, (ii) performing model-reduction where needed to derive low-order models suitable for controls analysis and design, (iii) developing a sensing system solution combining online sensors with model-based estimation for important process variables not measured directly, and (iv) optimizing the steady-state and transient operation of the plant for normal operation as well as for startup using model predictive controls (MPC). Initially, available process unit models were implemented in a common platform using Matlab/Simulink{reg_sign}, and appropriate model reduction and model updates were performed to obtain the overall gasification section dynamic model. Also, a set of sensor packages were developed through extensive lab testing and implemented in the Tampa Electric Company IGCC plant at Polk power station in 2009, to measure temperature and strain in the radiant syngas cooler (RSC). Plant operation data was also used to validate the overall gasification section model. The overall dynamic model was then used to develop a sensing solution including a set of online sensors coupled with model-based estimation using nonlinear extended Kalman filter (EKF). Its performance in terms of estimating key unmeasured variables like gasifier temperature, carbon conversion, etc., was studied through extensive simulations in the presence sensing errors (noise and bias) and modeling errors (e.g. unknown gasifier kinetics, RSC

  20. Integration of Distributed Services and Hybrid Models Based on Process Choreography to Predict and Detect Type 2 Diabetes. (United States)

    Martinez-Millana, Antonio; Bayo-Monton, Jose-Luis; Argente-Pla, María; Fernandez-Llatas, Carlos; Merino-Torres, Juan Francisco; Traver-Salcedo, Vicente


    Life expectancy is increasing and, so, the years that patients have to live with chronic diseases and co-morbidities. Type 2 diabetes is one of the most prevalent chronic diseases, specifically linked to being overweight and ages over sixty. Recent studies have demonstrated the effectiveness of new strategies to delay and even prevent the onset of type 2 diabetes by a combination of active and healthy lifestyle on cohorts of mid to high risk subjects. Prospective research has been driven on large groups of the population to build risk scores that aim to obtain a rule for the classification of patients according to the odds for developing the disease. Currently, there are more than two hundred models and risk scores for doing this, but a few have been properly evaluated in external groups and integrated into a clinical application for decision support. In this paper, we present a novel system architecture based on service choreography and hybrid modeling, which enables a distributed integration of clinical databases, statistical and mathematical engines and web interfaces to be deployed in a clinical setting. The system was assessed during an eight-week continuous period with eight endocrinologists of a hospital who evaluated up to 8080 patients with seven different type 2 diabetes risk models implemented in two mathematical engines. Throughput was assessed as a matter of technical key performance indicators, confirming the reliability and efficiency of the proposed architecture to integrate hybrid artificial intelligence tools into daily clinical routine to identify high risk subjects.

  1. Main neurosurgical pathologies in Benin Republic

    Directory of Open Access Journals (Sweden)

    Hugues Jean Thierry Gandaho


    Full Text Available Background: Benin republic is a very low-income French-speaking country in West Africa The development of Neurosurgery in the Republic of Benin took off with the arrival of the first Beninese neurosurgeons in the year 2003. Aims: This study aims to evaluate patients' attendance in a public neurosurgical center, and appreciate populations' affordability to a new specialty. Settings and Design: In the year 2004, the Benin Armed Forces established the first Department of Neurosurgery in the Nation's Military Teaching Hospital. From the public authorities, that was a proof of motivation to develop this specialty in the Benin Republic. Materials and Methods: A retrospective cross-sectional survey (September 2003 to December 2009 of the total neurosurgical patient population managed in a public pioneer hospital in a developing country. Statistical Analysis Used: Data were captured and analyzed with the SPSS software (SPSS Inc., Chicago, IL, USA and presented in descriptive statistics such as frequencies and proportions. Results: 2908 new patients, civilians, and militaries were registered. The surgical treatment was offered adult (86% as well as pediatric (14% patients. Spinal degenerative diseases (52.1% were the most common pathology; neurotraumatology emergency cases (8.4% appeared low in representation. Three-quarters of patients experienced financial difficulties to procure the required radiologic investigations and although 609 (20.94% benefited from surgery, most patients could not pay for the surgical operations as well as the perioperative care. Conclusions: In spite of the great constraints of this country's privately-funded health-care delivery system on the affordability of neurosurgical treatment for the average Beninese, this study demonstrates a globally increasing attendance of the department.

  2. Spine surgery training and competence of European Neurosurgical Trainees

    NARCIS (Netherlands)

    Boszczyk, Bronek Maximilian; Mooij, Jan Jakob; Schmitt, Natascha; Di Rocco, Concezio; Fakouri, Baroum Baroum; Lindsay, Kenneth W.

    Little is known about the nature of spine surgery training received by European neurosurgical trainees during their residency and the level of competence they acquire in dealing with spinal disorders. A three-part questionnaire entailing 32 questions was devised and distributed to the neurosurgical

  3. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp). (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures. (b...

  4. Using high-order polynomial basis in 3-D EM forward modeling based on volume integral equation method (United States)

    Kruglyakov, Mikhail; Kuvshinov, Alexey


    3-D interpretation of electromagnetic (EM) data of different origin and scale becomes a common practice worldwide. However, 3-D EM numerical simulations (modeling)—a key part of any 3-D EM data analysis—with realistic levels of complexity, accuracy and spatial detail still remains challenging from the computational point of view. We present a novel, efficient 3-D numerical solver based on a volume integral equation (IE) method. The efficiency is achieved by using a high-order polynomial (HOP) basis instead of the zero-order (piecewise constant) basis that is invoked in all routinely used IE-based solvers. We demonstrate that usage of the HOP basis allows us to decrease substantially the number of unknowns (preserving the same accuracy), with corresponding speed increase and memory saving.

  5. Model-based Impact Assessment of an Integrated Water Management Strategy on Ecosystem Services relevant to Food Security in Namibia (United States)

    Luetkemeier, R.; Liehr, S.


    North-central Namibia is characterized by seasonal alterations of drought and heavy rainfall, mostly saline groundwater resources and a lack of perennial rivers. Water scarcity poses a great challenge for freshwater supply, harvest and food security against the background of high population growth and climate change. CuveWaters project aims at poverty reduction and livelihood improvement on a long term basis by introducing a multi-resource-mix as part of an integrated water resources management (IWRM) approach. Herein, creating water buffers by rainwater harvesting (RWH) and subsurface water storage as well as reuse of treated wastewater facilitates micro-scale gardening activities. This link constitutes a major component of a sustainable adaptation strategy by contributing to the conservation and improvement of basic food and freshwater resources in order to reduce drought vulnerability. This paper presents main findings of an impact assessment carried out on the effect of integrated water resources management on ecosystem services (ESS) relevant to food security within the framework of CuveWaters project. North-central Namibia is perceived as a social-ecological system characterized by a strong mutual dependence between natural environment and anthropogenic system. This fundamental reliance on natural resources highlights the key role of ESS in semi-arid environments to sustain human livelihoods. Among other services, food provision was chosen for quantification as one of the most fundamental ESS in north-central Namibia. Different nutritional values were utilized as indicators to adopt a demand-supply approach (Ecosystem Service Profile) to illustrate the ability of the ecosystem to meet people's nutritional requirements. Calculations have been conducted using both Bayesian networks to incorporate uncertainty introduced by the variability of monthly precipitation and the application of plant specific water production functions. Results show that improving the

  6. Hybrid robust model based on an improved functional link neural network integrating with partial least square (IFLNN-PLS) and its application to predicting key process variables. (United States)

    He, Yan-Lin; Xu, Yuan; Geng, Zhi-Qiang; Zhu, Qun-Xiong


    In this paper, a hybrid robust model based on an improved functional link neural network integrating with partial least square (IFLNN-PLS) is proposed. Firstly, an improved functional link neural network with small norm of expanded weights and high input-output correlation (SNEWHIOC-FLNN) was proposed for enhancing the generalization performance of FLNN. Unlike the traditional FLNN, the expanded variables of the original inputs are not directly used as the inputs in the proposed SNEWHIOC-FLNN model. The original inputs are attached to some small norm of expanded weights. As a result, the correlation coefficient between some of the expanded variables and the outputs is enhanced. The larger the correlation coefficient is, the more relevant the expanded variables tend to be. In the end, the expanded variables with larger correlation coefficient are selected as the inputs to improve the performance of the traditional FLNN. In order to test the proposed SNEWHIOC-FLNN model, three UCI (University of California, Irvine) regression datasets named Housing, Concrete Compressive Strength (CCS), and Yacht Hydro Dynamics (YHD) are selected. Then a hybrid model based on the improved FLNN integrating with partial least square (IFLNN-PLS) was built. In IFLNN-PLS model, the connection weights are calculated using the partial least square method but not the error back propagation algorithm. Lastly, IFLNN-PLS was developed as an intelligent measurement model for accurately predicting the key variables in the Purified Terephthalic Acid (PTA) process and the High Density Polyethylene (HDPE) process. Simulation results illustrated that the IFLNN-PLS could significant improve the prediction performance. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  7. TU-G-210-02: TRANS-FUSIMO - An Integrative Approach to Model-Based Treatment Planning of Liver FUS

    Energy Technology Data Exchange (ETDEWEB)

    Preusser, T. [Fraunhofer MEVIS & Jacobs University (Germany)


    Modeling can play a vital role in predicting, optimizing and analyzing the results of therapeutic ultrasound treatments. Simulating the propagating acoustic beam in various targeted regions of the body allows for the prediction of the resulting power deposition and temperature profiles. In this session we will apply various modeling approaches to breast, abdominal organ and brain treatments. Of particular interest is the effectiveness of procedures for correcting for phase aberrations caused by intervening irregular tissues, such as the skull in transcranial applications or inhomogeneous breast tissues. Also described are methods to compensate for motion in targeted abdominal organs such as the liver or kidney. Douglas Christensen – Modeling for Breast and Brain HIFU Treatment Planning Tobias Preusser – TRANS-FUSIMO – An Integrative Approach to Model-Based Treatment Planning of Liver FUS Tobias Preusser – TRANS-FUSIMO – An Integrative Approach to Model-Based Treatment Planning of Liver FUS Learning Objectives: Understand the role of acoustic beam modeling for predicting the effectiveness of therapeutic ultrasound treatments. Apply acoustic modeling to specific breast, liver, kidney and transcranial anatomies. Determine how to obtain appropriate acoustic modeling parameters from clinical images. Understand the separate role of absorption and scattering in energy delivery to tissues. See how organ motion can be compensated for in ultrasound therapies. Compare simulated data with clinical temperature measurements in transcranial applications. Supported by NIH R01 HL172787 and R01 EB013433 (DC); EU Seventh Framework Programme (FP7/2007-2013) under 270186 (FUSIMO) and 611889 (TRANS-FUSIMO)(TP); and P01 CA159992, GE, FUSF and InSightec (UV)

  8. TU-G-210-02: TRANS-FUSIMO - An Integrative Approach to Model-Based Treatment Planning of Liver FUS

    International Nuclear Information System (INIS)

    Preusser, T.


    Modeling can play a vital role in predicting, optimizing and analyzing the results of therapeutic ultrasound treatments. Simulating the propagating acoustic beam in various targeted regions of the body allows for the prediction of the resulting power deposition and temperature profiles. In this session we will apply various modeling approaches to breast, abdominal organ and brain treatments. Of particular interest is the effectiveness of procedures for correcting for phase aberrations caused by intervening irregular tissues, such as the skull in transcranial applications or inhomogeneous breast tissues. Also described are methods to compensate for motion in targeted abdominal organs such as the liver or kidney. Douglas Christensen – Modeling for Breast and Brain HIFU Treatment Planning Tobias Preusser – TRANS-FUSIMO – An Integrative Approach to Model-Based Treatment Planning of Liver FUS Tobias Preusser – TRANS-FUSIMO – An Integrative Approach to Model-Based Treatment Planning of Liver FUS Learning Objectives: Understand the role of acoustic beam modeling for predicting the effectiveness of therapeutic ultrasound treatments. Apply acoustic modeling to specific breast, liver, kidney and transcranial anatomies. Determine how to obtain appropriate acoustic modeling parameters from clinical images. Understand the separate role of absorption and scattering in energy delivery to tissues. See how organ motion can be compensated for in ultrasound therapies. Compare simulated data with clinical temperature measurements in transcranial applications. Supported by NIH R01 HL172787 and R01 EB013433 (DC); EU Seventh Framework Programme (FP7/2007-2013) under 270186 (FUSIMO) and 611889 (TRANS-FUSIMO)(TP); and P01 CA159992, GE, FUSF and InSightec (UV)

  9. Resident away rotations allow adaptive neurosurgical training. (United States)

    Gephart, Melanie Hayden; Derstine, Pamela; Oyesiku, Nelson M; Grady, M Sean; Burchiel, Kim; Batjer, H Hunt; Popp, A John; Barbaro, Nicholas M


    Subspecialization of physicians and regional centers concentrate the volume of certain rare cases into fewer hospitals. Consequently, the primary institution of a neurological surgery training program may not have sufficient case volume to meet the current Residency Review Committee case minimum requirements in some areas. To ensure the competency of graduating residents through a comprehensive neurosurgical education, programs may need for residents to travel to outside institutions for exposure to cases that are either less common or more regionally focused. We sought to evaluate off-site rotations to better understand the changing demographics and needs of resident education. This would also allow prospective monitoring of modifications to the neurosurgery training landscape. We completed a survey of neurosurgery program directors and query of data from the Accreditation Council of Graduate Medical Education to characterize the current use of away rotations in neurosurgical education of residents. We found that 20% of programs have mandatory away rotations, most commonly for exposure to pediatric, functional, peripheral nerve, or trauma cases. Most of these rotations are done during postgraduate year 3 to 6, lasting 1 to 15 months. Twenty-six programs have 2 to 3 participating sites and 41 have 4 to 6 sites distinct from the host program. Programs frequently offset potential financial harm to residents rotating at a distant site by support of housing and transportation costs. As medical systems experience fluctuating treatment paradigms and demographics, over time, more residency programs may adapt to meet the Accreditation Council of Graduate Medical Education case minimum requirements through the implementation of away rotations.

  10. Neurosurgical Management of Nonmissile Penetrating Cranial Lesions. (United States)

    de Holanda, Luciano Ferreira; Pereira, Benedito Jamilson A; Holanda, Rafael Rodrigues; Neto, José Targino; de Holanda, Carlos Vanderlei M; Giudicissi Filho, Miguel; de Oliveira, Nathalia Ribeiro Cunha; de Oliveira, Jean G


    The objective of this study is to present a case series of nonmissile penetrating (NMP) injuries and to establish a workflow for an uncommon mechanism of traumatic head injury through the analysis of each case, classification of the type of lesion, management, and outcome score at follow-up. From January 1991 to December 2008, 36,000 patients presenting with traumatic brain injury (TBI) were admitted in the Department of Neurosurgery, Hospital Antônio Targino, Campina Grande-PB, Brazil. From these patients, 11 presenting with lesions caused by NMP objects were selected. Among the 11 patients, 9 were men and 2 were women. Their ages ranged from 7 to 74 years old (mean age ± SD, 29.1 ± 22.99 years). All patients underwent neuroradiologic evaluation. The entry point was classified as natural (orbit) or artificial (skull transfixation), and we also divided the patients presenting with secondary parenchymal or vascular damage from those presenting with only lesions caused by the primary penetration into the cranium and meninges. All patients were neurosurgically treated with removal of the foreign body through craniotomy, except the patient whose object (pen) was removed without craniotomy with local anesthesia. Glasgow Coma Scale (GCS) score on admission was a statistically significant factor on prognosis, and any patient who presented with a GCS score of 15 evolved satisfactorily, and there were no deaths in this group of patients (P = 0.04). TBIs caused by NMP objects are unusual and caused by aggression, self-inflicted harm (in the case of psychiatric patients), and accident. The foreign body may enter into the skull through a natural hole (orbit, nose, mouth, or ear) or crosses the skull, causing a fracture and creating an artificial hole. Preoperative neuroradiologic assessment is paramount for the correct neurosurgical approach. The main prognostic factor for these patients is the GCS score at admission. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Pain in neurosurgically treated patients: A prospective observational study

    NARCIS (Netherlands)

    M. Klimek (Markus); J.F. Ubben (Johannes); J. Ammann (Jan); K. Borner (Katy); J. Klein (Jan); S.J.C. Verbrugge (Serge)


    textabstractObject. This is the first observational study to compare perioperative pain character and intensity in patients undergoing different types of elective neurosurgical procedures. Methods. A structured questionnaire was used to inquire about pain intensity, character, and management during

  12. Three-dimensional spiral CT for neurosurgical planning. (United States)

    Klein, H M; Bertalanffy, H; Mayfrank, L; Thron, A; Günther, R W; Gilsbach, J M


    We carried out 22 examinations to determine the value of three-dimensional (3D) volumetric CT (spiral CT) for planning neurosurgical procedures. All examinations were carried out on a of the first generation spiral CT. A tube model was used to investigate the influence of different parameter settings. Bolus injection of nonionic contrast medium was used when vessels or strongly enhancing tumours were to be delineated. 3D reconstructions were carried out using the integrated 3D software of the scanner. We found a table feed of 3 mm/s with a slice thickness of 2 mm and an increment of 1 mm to be suitable for most purposes. For larger regions of interest a table feed of 5 mm was the maximum which could be used without blurring of the 3D images. Particular advantages of 3D reconstructed spiral scanning were seen in the planning of approaches to the lower clivus, acquired or congenital bony abnormalities and when the relationship between vessels, tumour and bone was important.

  13. Three-dimensional spiral CT for neurosurgical planning

    International Nuclear Information System (INIS)

    Klein, H.M.; Bertalanffy, H.; Mayfrank, L.; Thron, A.; Guenther, R.W.; Gilsbach, J.M.


    We carried out 22 examinations to determine the value of three-dimensional (3D) volumetric CT (spiral CT) for planning neurosurgical procedures. All examinations were carried out on a of the first generation spiral CT. A tube model was used to investigate the influence of different parameter settings. Bolus injection of nonionic contrast medium was used when vessels or strongly enhancing tumours were to be delineated. 3D reconstructions were carried out using the integrated 3D software of the scanner. We found a table feed of 3 mm/s with a slice thickness of 2 mm and an increment of 1 mm to be suitable for most purposes. For larger regions of interest a table feed of 5 mm was the maximum which could be used without blurring of the 3D images. Particular advantages of 3D reconstructed spiral scanning were seen in the planning of approaches to the lower clivus, acquired or congenital bony abnormalities and when the relationship between vessels, tumour and bone was important. (orig.)

  14. Role of cranial and spinal virtual and augmented reality simulation using immersive touch modules in neurosurgical training. (United States)

    Alaraj, Ali; Charbel, Fady T; Birk, Daniel; Tobin, Matthew; Tobin, Mathew; Luciano, Cristian; Banerjee, Pat P; Rizzi, Silvio; Sorenson, Jeff; Foley, Kevin; Slavin, Konstantin; Roitberg, Ben


    Recent studies have shown that mental script-based rehearsal and simulation-based training improve the transfer of surgical skills in various medical disciplines. Despite significant advances in technology and intraoperative techniques over the last several decades, surgical skills training on neurosurgical operations still carries significant risk of serious morbidity or mortality. Potentially avoidable technical errors are well recognized as contributing to poor surgical outcome. Surgical education is undergoing overwhelming change, as a result of the reduction of work hours and current trends focusing on patient safety and linking reimbursement with clinical outcomes. Thus, there is a need for adjunctive means for neurosurgical training, which is a recent advancement in simulation technology. ImmersiveTouch is an augmented reality system that integrates a haptic device and a high-resolution stereoscopic display. This simulation platform uses multiple sensory modalities, re-creating many of the environmental cues experienced during an actual procedure. Modules available include ventriculostomy, bone drilling, percutaneous trigeminal rhizotomy, and simulated spinal modules such as pedicle screw placement, vertebroplasty, and lumbar puncture. We present our experience with the development of such augmented reality neurosurgical modules and the feedback from neurosurgical residents.

  15. Role of Cranial and Spinal Virtual and Augmented Reality Simulation Using Immersive Touch Modules in Neurosurgical Training (United States)

    Alaraj, Ali; Charbel, Fady T.; Birk, Daniel; Tobin, Mathew; Luciano, Cristian; Banerjee, Pat P.; Rizzi, Silvio; Sorenson, Jeff; Foley, Kevin; Slavin, Konstantin; Roitberg, Ben


    Recent studies have shown that mental script-based rehearsal and simulation-based training improves the transfer of surgical skills in various medical disciplines. Despite significant advances in technology and intraoperative techniques over the last several decades, surgical skills training on neurosurgical operations still carries significant risk of serious morbidity or mortality. Potentially avoidable technical errors are well recognized as contributing to poor surgical outcome. Surgical education is undergoing overwhelming change, with reduction of working hours and current trends to focus on patient’s safety and linking reimbursement with clinical outcomes, and there is a need for adjunctive means for neurosurgical training;this has been recent advancement in simulation technology. ImmersiveTouch (IT) is an augmented reality (AR) system that integrates a haptic device and a high-resolution stereoscopic display. This simulation platform utilizes multiple sensory modalities, recreating many of the environmental cues experienced during an actual procedure. Modules available include ventriculostomy, bone drilling, percutaneous trigeminal rhizotomy, in addition to simulated spinal modules such as pedicle screw placement, vertebroplasty, and lumbar puncture. We present our experience with development of such AR neurosurgical modules and the feedback from neurosurgical residents. PMID:23254799

  16. Quantitative fluorescence angiography for neurosurgical interventions. (United States)

    Weichelt, Claudia; Duscha, Philipp; Steinmeier, Ralf; Meyer, Tobias; Kuß, Julia; Cimalla, Peter; Kirsch, Matthias; Sobottka, Stephan B; Koch, Edmund; Schackert, Gabriele; Morgenstern, Ute


    Present methods for quantitative measurement of cerebral perfusion during neurosurgical operations require additional technology for measurement, data acquisition, and processing. This study used conventional fluorescence video angiography--as an established method to visualize blood flow in brain vessels--enhanced by a quantifying perfusion software tool. For these purposes, the fluorescence dye indocyanine green is given intravenously, and after activation by a near-infrared light source the fluorescence signal is recorded. Video data are analyzed by software algorithms to allow quantification of the blood flow. Additionally, perfusion is measured intraoperatively by a reference system. Furthermore, comparing reference measurements using a flow phantom were performed to verify the quantitative blood flow results of the software and to validate the software algorithm. Analysis of intraoperative video data provides characteristic biological parameters. These parameters were implemented in the special flow phantom for experimental validation of the developed software algorithms. Furthermore, various factors that influence the determination of perfusion parameters were analyzed by means of mathematical simulation. Comparing patient measurement, phantom experiment, and computer simulation under certain conditions (variable frame rate, vessel diameter, etc.), the results of the software algorithms are within the range of parameter accuracy of the reference methods. Therefore, the software algorithm for calculating cortical perfusion parameters from video data presents a helpful intraoperative tool without complex additional measurement technology.

  17. Evaluation of a completely robotized neurosurgical operating microscope. (United States)

    Kantelhardt, Sven R; Finke, Markus; Schweikard, Achim; Giese, Alf


    Operating microscopes are essential for most neurosurgical procedures. Modern robot-assisted controls offer new possibilities, combining the advantages of conventional and automated systems. We evaluated the prototype of a completely robotized operating microscope with an integrated optical coherence tomography module. A standard operating microscope was fitted with motors and control instruments, with the manual control mode and balance preserved. In the robot mode, the microscope was steered by a remote control that could be fixed to a surgical instrument. External encoders and accelerometers tracked microscope movements. The microscope was additionally fitted with an optical coherence tomography-scanning module. The robotized microscope was tested on model systems. It could be freely positioned, without forcing the surgeon to take the hands from the instruments or avert the eyes from the oculars. Positioning error was about 1 mm, and vibration faded in 1 second. Tracking of microscope movements, combined with an autofocus function, allowed determination of the focus position within the 3-dimensional space. This constituted a second loop of navigation independent from conventional infrared reflector-based techniques. In the robot mode, automated optical coherence tomography scanning of large surface areas was feasible. The prototype of a robotized optical coherence tomography-integrated operating microscope combines the advantages of a conventional manually controlled operating microscope with a remote-controlled positioning aid and a self-navigating microscope system that performs automated positioning tasks such as surface scans. This demonstrates that, in the future, operating microscopes may be used to acquire intraoperative spatial data, volume changes, and structural data of brain or brain tumor tissue.

  18. Neurosurgical procedures in Jehovah's Witnesses: the Tema experience. (United States)

    Andrews, N B


    On account of religious reasons, Jehovah Witnesses do not accept blood or blood products; occasionally, they accept reinfusion of autologous blood via a cell saver during surgery. The aim of this study was to document the demographics of Jehovah Witnesses undergoing neurosurgical procedures, the neurosurgical procedures undertaken in Jehovah Witnesses and to evaluate the complications of the procedures. A retrospective audit of the medical records of all Jehovah's Witnesses who underwent neurosurgical procedures at our institution, from January 1st 2000 to December 31st 2006, was carried out. The parameters investigated included demographics, pre and post operative diagnosis, type of neurosurgical procedure and complications. Nineteen patients (fifteen male, four female; male/female 3.8:1) constituted the series. The mean age was 45.8 (range: 20-65) years. A total of 21 procedures were performed; intracranial surgery (33%), spinal surgery (67%). No autotransfusion of blood was given. Lumbar laminectomy for stenosis was the commonest spine procedure, ten (71.4%); craniotomy for tumor excision was the commonest intracranial procedure, six (85.7%). With respect to the whole series, the morbidity rate was 4.7% and the mortality rate was 4.7%; both were from intracranial surgery. It is possible to perform certain types of neurosurgical procedures in Jehovah's Witnesses without increasing the mortality and morbidity rate.

  19. Neurosurgical operating computerized tomographic scanner system

    International Nuclear Information System (INIS)

    Okudera, Hiroshi; Sugita, Kenichiro; Kobayashi, Shigeaki; Kimishima, Sakae; Yoshida, Hisashi.


    A neurosurgical operating computerized tomography scanner system is presented. This system has been developed for obtaining intra- and postoperative CT images in the operating room. A TCT-300 scanner (manufactured by the Toshiba Co., Tokyo) is placed in the operating room. The realization of a true intraoperative CT image requires certain improvements in the CT scanner and operating table. To adjust the axis of the co-ordinates of the motor system of the MST-7000 microsurgical operating table (manufactured by the Mizuho Ika Co., Tokyo) to the CT scanner, we have designed an interface and a precise motor system so that the computer of the CT scanner can directly control the movement of the operating table. Furthermore, a new head-fixation system has been designed for producing artifact-free intraoperative CT images. The head-pins of the head-fixation system are made of carbon-fiber bars and titanium tips. A simulation study of the total system in the operating room with the CT scanner, operating table, and head holder using a skull model yielded a degree of error similar to that in the phantom testing of the original scanner. Three patients underwent resection of a glial tumor using this system. Intraoperative CT scans taken after dural opening showed a bulging of the cortex, a shift in the central structure, and a displacement of the cortical subarachnoid spaces under the influence of gravity. With a contrast medium the edge of the surrounding brain after resection was enhanced and the residual tumor mass was demonstrated clearly. This system makes it possible to obtain a noninvasive intraoperative image in a situation where structural shifts are taking place. (author)

  20. Evaluating the Effectiveness and the Impact of Donated Neurosurgical Equipment on Neurosurgical Units in Low- and Middle-Income Countries: The World Federation of Neurosurgical Societies Experience. (United States)

    Venturini, Sara; Park, Kee B


    Surgical practice highly depends on the availability of surgical equipment; this is particularly relevant to low- and middle-income countries (LMICs), where resources are limited. A key part of the efforts to improve surgical provision globally include providing affordable equipment to LMICs; however, the effectiveness and the impact of these initiatives have not yet been assessed. We aimed to evaluate the World Federation of Neurosurgical Societies neurosurgical equipment program in this context. Recipients were identified from the World Federation of Neurosurgical Societies records; contact details were gathered. An online survey was used to collect data on equipment, including its current use, any malfunctioning issues, suitability, reliability, serviceability, and the impact it has had on the unit. Responses were received from 16 units, totaling 28 pieces of equipment. A total of 75% of the equipment is still in use; of this, 57% is fully functioning, and 43% is used despite some malfunction. We found that 25% of the equipment is broken and unusable; high-maintenance items, such as high-speed drills, feature in this category (100% broken, n = 3). Units reported an increase in number of operation performed in 74% cases, improved surgery quality in 78%, and breadth of operations in 44%. Satisfaction, equipment suitability, reliability, and serviceability scored highly, with median values of 9 for all fields on a 10-point scale. Equipment donation positively impacts neurosurgical units in LMICs by allowing expansion of neurosurgical practice, improved safety and quality, and affordability. Adequate follow-up, considerations regarding equipment durability and maintenance needs, and improved support for repairs should be prioritized to ensure maximal benefit. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Blood transfusion indications in neurosurgical patients: A systematic review. (United States)

    Bagwe, Shefali; Chung, Lawrance K; Lagman, Carlito; Voth, Brittany L; Barnette, Natalie E; Elhajjmoussa, Lekaa; Yang, Isaac


    Neurosurgical procedures can be complicated by significant blood losses that have the potential to decrease tissue perfusion to critical brain tissue. Red blood cell transfusion is used in a variety of capacities both inside, and outside, of the operating room to prevent untoward neurologic damage. However, evidence-based guidelines concerning thresholds and indications for transfusion in neurosurgery remain limited. Consequently, transfusion practices in neurosurgical patients are highly variable and based on institutional experiences. Recently, a paradigm shift has occurred in neurocritical intensive care units, whereby restrictive transfusion is increasingly favored over liberal transfusion but the ideal strategy remains in clinical equipoise. The authors of this study perform a systematic review of the literature with the objective of capturing the changing landscape of blood transfusion indications in neurosurgical patients. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Diagnosis and treatment of hyponatraemia in neurosurgical patients. (United States)

    Cuesta, Martín; Hannon, Mark J; Thompson, Christopher J


    Hyponatraemia is the most common electrolyte imbalance in neurosurgical patients. Acute hyponatraemia is particularly common in neurosurgical patients after any type of brain insult, including brain tumours and their treatment, pituitary surgery, subarachnoid haemorrhage or traumatic brain injury. Acute hyponatraemia is an emergency condition, as it leads to cerebral oedema due to passive osmotic movement of water from the hypotonic plasma to the relatively hypertonic brain which ultimately is the cause of the symptoms associated with hyponatraemia. These include decreased level of consciousness, seizures, non-cardiogenic pulmonary oedema or transtentorial brain herniation. Prompt treatment is mandatory to prevent such complications, minimize permanent brain damage and therefore permit rapid recovery after brain insult. The infusion of 3% hypertonic saline is the treatment of choice with different rates of administration based on the severity of symptoms and the rate of drop in plasma sodium concentration. The pathophysiology of hyponatraemia in neurotrauma is multifactorial; although the syndrome of inappropriate antidiuresis (SIADH) and central adrenal insufficiency are the commonest causes encountered. Fluid restriction has historically been the classical treatment for SIADH, although it is relatively contraindicated in some neurosurgical patients such as those with subarachnoid haemorrhage. Furthermore, many cases admitted have acute onset hyponatraemia, who require hypertonic saline infusion. The recently developed vasopressin receptor 2 antagonist class of drug is a promising and effective tool but more evidence is needed in neurosurgical patients. Central adrenal insufficiency may also cause acute hyponatraemia in neurosurgical patients; this responds clinically and biochemically to hydrocortisone. The rare cerebral salt wasting syndrome is treated with large volume normal saline infusion. In this review, we summarize the current evidence based on the

  3. Needs Assessment for Incoming PGY-1 Residents in Neurosurgical Residency. (United States)

    Brandman, David M; Haji, Faizal A; Matte, Marie C; Clarke, David B


    Residents must develop a diverse range of skills in order to practice neurosurgery safely and effectively. The purpose of this study was to identify the foundational skills required for neurosurgical trainees as they transition from medical school to residency. Based on the CanMEDS competency framework, a web-based survey was distributed to all Canadian academic neurosurgical centers, targeting incoming and current PGY-1 neurosurgical residents as well as program directors. Using Likert scale and free-text responses, respondents rated the importance of various cognitive (e.g. management of raised intracranial pressure), technical (e.g. performing a lumbar puncture) and behavioral skills (e.g. obtaining informed consent) required for a PGY-1 neurosurgical resident. Of 52 individuals contacted, 38 responses were received. Of these, 10 were from program directors (71%), 11 from current PGY-1 residents (58%) and 17 from incoming PGY-1 residents (89%). Respondents emphasized operative skills such as proper sterile technique and patient positioning; clinical skills such as lesion localization and interpreting neuro-imaging; management skills for common scenarios such as raised intracranial pressure and status epilepticus; and technical skills such as lumbar puncture and external ventricular drain placement. Free text answers were concordant with the Likert scale results. We surveyed Canadian neurosurgical program directors and PGY-1 residents to identify areas perceived as foundational to neurosurgical residency education and training. This information is valuable for evaluating the appropriateness of a training program's goals and objectives, as well as for generating a national educational curriculum for incoming PGY-1 residents.

  4. The history of neurosurgical treatment of sports concussion. (United States)

    Stone, James L; Patel, Vimal; Bailes, Julian E


    Concussion has a long and interesting history spanning at least the 5 millennia of written medical record and closely mirrors the development of surgery and neurosurgery. Not surprisingly, much of the past and present experimental head injury and concussion work has been performed within neurosurgically driven laboratories or by several surgically oriented neurologists. This historical review chronicles the key aspects of neurosurgical involvement in sports concussion as related to the diagnosis, treatment, mitigation, and prevention of injury using the example of American football. In addition, we briefly trace the developments that led to our current understanding of the biomechanical and neurophysiological basis of concussion.

  5. Neurosurgical In-Patient Profile: A Three-Year Audit in a Regional ...

    African Journals Online (AJOL)

    The burden of neurosurgical care in West Africa, compared with established facilities in Europe and America, is immense. The reasons include preventable neurotrauma, the dearth of specialists and a lack of a regional centre for neurosurgical care. The few unevenly spread established neurosurgical units can only meet ...

  6. Synoptic philosophy in a neurosurgical residency: a book and cinema club. (United States)

    Wadhwa, Rishi; Thakur, Jai Deep; Cardenas, Raul; Wright, Jeri; Nanda, Anil


    Introduction of a book and cinema club in a Department of Neurosurgery has helped combine an education in humanities with neurosurgical training. The authors believe the addition of teaching in humanities adds to the specialty and helps in fulfilling the six core competencies of the Accreditation Council for Graduate Medical Education. The goal is to encourage synoptic philosophy and impart creative ways of interacting with the world. Books and movies with a medical basis and nonmedical basis were selected and reviewed in an open forum. Efforts were made to integrate the Accreditation Council for Graduate Medical Education six core competencies into the discussions. Residents anonymously completed a questionnaire pertaining to the usefulness of the book club in residency. There were 13 residents who attended the sessions and responded to the questionnaire. Of residents, 61.5% believed the topics were pertinent to their everyday life, and 77% believed that the club had helped them somehow in residency. Most (7 of 13) believed the club should not be included as part of the curriculum in an 80-hour work week. Institution of a book and movie club seems to be an effective way of integrating humanities within a neurosurgical residency. Published by Elsevier Inc.

  7. Google Search Queries About Neurosurgical Topics: Are They a Suitable Guide for Neurosurgeons? (United States)

    Lawson McLean, Anna C; Lawson McLean, Aaron; Kalff, Rolf; Walter, Jan


    Google is the most popular search engine, with about 100 billion searches per month. Google Trends is an integrated tool that allows users to obtain Google's search popularity statistics from the last decade. Our aim was to evaluate whether Google Trends is a useful tool to assess the public's interest in specific neurosurgical topics. We evaluated Google Trends statistics for the neurosurgical search topic areas "hydrocephalus," "spinal stenosis," "concussion," "vestibular schwannoma," and "cerebral arteriovenous malformation." We compared these with bibliometric data from PubMed and epidemiologic data from the German Federal Monitoring Agency. In addition, we assessed Google users' search behavior for the search terms "glioblastoma" and "meningioma." Over the last 10 years, there has been an increasing interest in the topic "concussion" from Internet users in general and scientists. "Spinal stenosis," "concussion," and "vestibular schwannoma" are topics that are of special interest in high-income countries (eg, Germany), whereas "hydrocephalus" is a popular topic in low- and middle-income countries. The Google-defined top searches within these topic areas revealed more detail about people's interests (eg, "normal pressure hydrocephalus" or "football concussion" ranked among the most popular search queries within the corresponding topics). There was a similar volume of queries for "glioblastoma" and "meningioma." Google Trends is a useful source to elicit information about general trends in peoples' health interests and the role of different diseases across the world. The Internet presence of neurosurgical units and surgeons can be guided by online users' interests to achieve high-quality, professional-endorsed patient education. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Diagnostic accuracy of routine blood examinations and CSF lactate level for post-neurosurgical bacterial meningitis. (United States)

    Zhang, Yang; Xiao, Xiong; Zhang, Junting; Gao, Zhixian; Ji, Nan; Zhang, Liwei


    To evaluate the diagnostic accuracy of routine blood examinations and Cerebrospinal Fluid (CSF) lactate level for Post-neurosurgical Bacterial Meningitis (PBM) at a large sample-size of post-neurosurgical patients. The diagnostic accuracies of routine blood examinations and CSF lactate level to distinguish between PAM and PBM were evaluated with the values of the Area Under the Curve of the Receiver Operating Characteristic (AUC -ROC ) by retrospectively analyzing the datasets of post-neurosurgical patients in the clinical information databases. The diagnostic accuracy of routine blood examinations was relatively low (AUC -ROC CSF lactate level achieved rather high diagnostic accuracy (AUC -ROC =0.891; CI 95%, 0.852-0.922). The variables of patient age, operation duration, surgical diagnosis and postoperative days (the interval days between the neurosurgery and examinations) were shown to affect the diagnostic accuracy of these examinations. The variables were integrated with routine blood examinations and CSF lactate level by Fisher discriminant analysis to improve their diagnostic accuracy. As a result, the diagnostic accuracy of blood examinations and CSF lactate level was significantly improved with an AUC -ROC value=0.760 (CI 95%, 0.737-0.782) and 0.921 (CI 95%, 0.887-0.948) respectively. The PBM diagnostic accuracy of routine blood examinations was relatively low, whereas the accuracy of CSF lactate level was high. Some variables that are involved in the incidence of PBM can also affect the diagnostic accuracy for PBM. Taking into account the effects of these variables significantly improves the diagnostic accuracies of routine blood examinations and CSF lactate level. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Brevibacterium otitidis: an elusive cause of neurosurgical infection.

    LENUS (Irish Health Repository)

    Fe Talento, Alida


    Coryneform bacteria are usually considered as non-pathogenic when isolated from clinical specimens. We present a case of Brevibacterium otitidis neurosurgical infection in an immunocompetent patient, and highlight the difficulty with identification and interpretation of antimicrobial susceptibility results for this unusual pathogen.

  10. Drug-resistant post-neurosurgical nosocomial Acinetobacter ...

    African Journals Online (AJOL)

    Drug-resistant post-neurosurgical nosocomial Acinetobacter baumannii meningitis in two Iranian hospitals. ... Vol 11, No 17 (2012) >. Log in or Register to get access to full text downloads. ... Acinetobacter baumannii may cause meningitis and ventriculitis, particularly after head trauma and/or neurosurgery. The rate of ...

  11. Ventriculostomy infections at the paediatric neurosurgical unit at Dr ...

    African Journals Online (AJOL)

    of patients admitted to the paediatric neurosurgical unit at the hospital between January 2010 and December 2013, who had had an EVD inserted as part of their treatment, and if all records were accurate, legible and complete. Patients were excluded from the study if they were older than 12 years. Information was sourced ...

  12. An anatomical study of the different neurosurgical approaches of the ...

    African Journals Online (AJOL)

    Objective: This study was done to study the feasibility of the various neurosurgical approaches of the cervical spinal cord. Methods: Ten cadaveric specimens obtained from the dissecting room of the Faculty of Medicine, University of Alexandria were dissected both anteriorly and posteriorly in the cervical region to compare ...

  13. [Fusion of MRI, fMRI and intraoperative MRI data. Methods and clinical significance exemplified by neurosurgical interventions]. (United States)

    Moche, M; Busse, H; Dannenberg, C; Schulz, T; Schmitgen, A; Trantakis, C; Winkler, D; Schmidt, F; Kahn, T


    The aim of this work was to realize and clinically evaluate an image fusion platform for the integration of preoperative MRI and fMRI data into the intraoperative images of an interventional MRI system with a focus on neurosurgical procedures. A vertically open 0.5 T MRI scanner was equipped with a dedicated navigation system enabling the registration of additional imaging modalities (MRI, fMRI, CT) with the intraoperatively acquired data sets. These merged image data served as the basis for interventional planning and multimodal navigation. So far, the system has been used in 70 neurosurgical interventions (13 of which involved image data fusion--requiring 15 minutes extra time). The augmented navigation system is characterized by a higher frame rate and a higher image quality as compared to the system-integrated navigation based on continuously acquired (near) real time images. Patient movement and tissue shifts can be immediately detected by monitoring the morphological differences between both navigation scenes. The multimodal image fusion allowed a refined navigation planning especially for the resection of deeply seated brain lesions or pathologies close to eloquent areas. Augmented intraoperative orientation and instrument guidance improve the safety and accuracy of neurosurgical interventions.

  14. Implementing Functional Preoperative Mapping in the Clinical Routine of a Neurosurgical Department: Technical Note. (United States)

    Sollmann, Nico; Meyer, Bernhard; Krieg, Sandro M


    Navigated transcranial magnetic stimulation (nTMS) is increasingly being used for mapping of various brain functions and in nTMS-based tractography in neurosurgical departments worldwide. When a department begins using nTMS data in the clinical workflow, smooth integration into the hospital's existing infrastructure is mandatory. Standardized approaches for this beyond the mapping or tractography procedures themselves have not yet been described. To create an effective workflow for neurosurgical nTMS mapping, we present the findings of our 7 years of experience and progressive integration into the clinical routine. After indication for mapping is made, the workflow starts with patient admission and includes all preoperative steps until tumor resection. Importantly, only standard software and devices were used, enabling new centers to easily integrate data derived from nTMS mapping and nTMS-based tractography into their hospital's infrastructure. Registration of the patient, appointment planning, and documentation of results of the nTMS procedures within the hospital information system (HIS) can be achieved by a novel tailored software mask. As another important part of the workflow, nTMS data are imported into the picture archiving and communication system (PACS) via PACS integrator software. In addition, for surgical planning including nTMS-based tractography, nTMS data can be effectively included in surgical neuronavigation software. Optimized integration of nTMS data can be achieved using a standardized workflow. The seamless integration and availability of nTMS data are crucial to the acceptance of these data in the clinical routine. This optimized workflow can serve as a guide for centers beginning to use nTMS data in patient care. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. The Current State of Rural Neurosurgical Practice: An International Perspective. (United States)

    Upadhyayula, Pavan S; Yue, John K; Yang, Jason; Birk, Harjus S; Ciacci, Joseph D


    Rural and low-resource areas have diminished capacity to care for neurosurgical patients due to lack of infrastructure, healthcare investment, and training programs. This review summarizes the range of rural neurosurgical procedures, novel mechanisms for delivering care, rapid training programs, and outcome differences across international rural neurosurgical practice. A comprehensive literature search was performed for English language manuscripts with keywords "rural" and "neurosurgery" using the National Library of Medicine PubMed database (01/1971-06/2017). Twenty-four articles focusing on rural non-neurosurgical practice were included. Time to care and/or surgery and shortage of trained personnel remain the strongest risk factors for mortality and poor outcome. Telemedicine consults to regional centers with neurosurgery housestaff have potential for increased timeliness of diagnosis/triage, improved time to surgery, and reductions in unnecessary transfers in remote areas. Mobile neurosurgery teams have been deployed with success in nations with large transport distances precluding initial transfers. Common neurosurgical procedures involve trauma mechanisms; accordingly, training programs for nonneurosurgery medical personnel on basic assessment and operative techniques have been successful in resource-deficient settings where neurosurgeons are unavailable. Protracted transport times, lack of resources/training, and difficulty retaining specialists are barriers to successful outcomes. Advances in telemedicine, mobile neurosurgery, and training programs for urgent operative techniques have been implemented efficaciously. Development of guidelines for paired partnerships between rural centers and academic hospitals, supplying surplus technology to rural areas, and rapid training of qualified local surgical personnel can create sustainable feed-forward programs for trainees and infrastructural solutions to address challenges in rural neurosurgery.

  16. The current state of rural neurosurgical practice: An international perspective

    Directory of Open Access Journals (Sweden)

    Pavan S Upadhyayula


    Full Text Available Introduction: Rural and low-resource areas have diminished capacity to care for neurosurgical patients due to lack of infrastructure, healthcare investment, and training programs. This review summarizes the range of rural neurosurgical procedures, novel mechanisms for delivering care, rapid training programs, and outcome differences across international rural neurosurgical practice. Methods: A comprehensive literature search was performed for English language manuscripts with keywords “rural” and “neurosurgery” using the National Library of Medicine PubMed database (01/1971–06/2017. Twenty-four articles focusing on rural non-neurosurgical practice were included. Results: Time to care and/or surgery and shortage of trained personnel remain the strongest risk factors for mortality and poor outcome. Telemedicine consults to regional centers with neurosurgery housestaff have potential for increased timeliness of diagnosis/triage, improved time to surgery, and reductions in unnecessary transfers in remote areas. Mobile neurosurgery teams have been deployed with success in nations with large transport distances precluding initial transfers. Common neurosurgical procedures involve trauma mechanisms; accordingly, training programs for nonneurosurgery medical personnel on basic assessment and operative techniques have been successful in resource-deficient settings where neurosurgeons are unavailable. Conclusions: Protracted transport times, lack of resources/training, and difficulty retaining specialists are barriers to successful outcomes. Advances in telemedicine, mobile neurosurgery, and training programs for urgent operative techniques have been implemented efficaciously. Development of guidelines for paired partnerships between rural centers and academic hospitals, supplying surplus technology to rural areas, and rapid training of qualified local surgical personnel can create sustainable feed-forward programs for trainees and

  17. An introduction and overview of machine learning in neurosurgical care. (United States)

    Senders, Joeky T; Zaki, Mark M; Karhade, Aditya V; Chang, Bliss; Gormley, William B; Broekman, Marike L; Smith, Timothy R; Arnaout, Omar


    Machine learning (ML) is a branch of artificial intelligence that allows computers to learn from large complex datasets without being explicitly programmed. Although ML is already widely manifest in our daily lives in various forms, the considerable potential of ML has yet to find its way into mainstream medical research and day-to-day clinical care. The complex diagnostic and therapeutic modalities used in neurosurgery provide a vast amount of data that is ideally suited for ML models. This systematic review explores ML's potential to assist and improve neurosurgical care. A systematic literature search was performed in the PubMed and Embase databases to identify all potentially relevant studies up to January 1, 2017. All studies were included that evaluated ML models assisting neurosurgical treatment. Of the 6,402 citations identified, 221 studies were selected after subsequent title/abstract and full-text screening. In these studies, ML was used to assist surgical treatment of patients with epilepsy, brain tumors, spinal lesions, neurovascular pathology, Parkinson's disease, traumatic brain injury, and hydrocephalus. Across multiple paradigms, ML was found to be a valuable tool for presurgical planning, intraoperative guidance, neurophysiological monitoring, and neurosurgical outcome prediction. ML has started to find applications aimed at improving neurosurgical care by increasing the efficiency and precision of perioperative decision-making. A thorough validation of specific ML models is essential before implementation in clinical neurosurgical care. To bridge the gap between research and clinical care, practical and ethical issues should be considered parallel to the development of these techniques.

  18. The Current State of Rural Neurosurgical Practice: An International Perspective (United States)

    Upadhyayula, Pavan S.; Yue, John K.; Yang, Jason; Birk, Harjus S.; Ciacci, Joseph D.


    Introduction: Rural and low-resource areas have diminished capacity to care for neurosurgical patients due to lack of infrastructure, healthcare investment, and training programs. This review summarizes the range of rural neurosurgical procedures, novel mechanisms for delivering care, rapid training programs, and outcome differences across international rural neurosurgical practice. Methods: A comprehensive literature search was performed for English language manuscripts with keywords “rural” and “neurosurgery” using the National Library of Medicine PubMed database (01/1971–06/2017). Twenty-four articles focusing on rural non-neurosurgical practice were included. Results: Time to care and/or surgery and shortage of trained personnel remain the strongest risk factors for mortality and poor outcome. Telemedicine consults to regional centers with neurosurgery housestaff have potential for increased timeliness of diagnosis/triage, improved time to surgery, and reductions in unnecessary transfers in remote areas. Mobile neurosurgery teams have been deployed with success in nations with large transport distances precluding initial transfers. Common neurosurgical procedures involve trauma mechanisms; accordingly, training programs for nonneurosurgery medical personnel on basic assessment and operative techniques have been successful in resource-deficient settings where neurosurgeons are unavailable. Conclusions: Protracted transport times, lack of resources/training, and difficulty retaining specialists are barriers to successful outcomes. Advances in telemedicine, mobile neurosurgery, and training programs for urgent operative techniques have been implemented efficaciously. Development of guidelines for paired partnerships between rural centers and academic hospitals, supplying surplus technology to rural areas, and rapid training of qualified local surgical personnel can create sustainable feed-forward programs for trainees and infrastructural solutions to

  19. MRI-guided stereotactic neurosurgical procedures in a diagnostic MRI suite: Background and safe practice recommendations. (United States)

    Larson, Paul S; Willie, Jon T; Vadivelu, Sudhakar; Azmi-Ghadimi, Hooman; Nichols, Amy; Fauerbach, Loretta Litz; Johnson, Helen Boehm; Graham, Denise


    The development of navigation technology facilitating MRI-guided stereotactic neurosurgery has enabled neurosurgeons to perform a variety of procedures ranging from deep brain stimulation to laser ablation entirely within an intraoperative or diagnostic MRI suite while having real-time visualization of brain anatomy. Prior to this technology, some of these procedures required multisite workflow patterns that presented significant risk to the patient during transport. For those facilities with access to this technology, safe practice guidelines exist only for procedures performed within an intraoperative MRI. There are currently no safe practice guidelines or parameters available for facilities looking to integrate this technology into practice in conventional MRI suites. Performing neurosurgical procedures in a diagnostic MRI suite does require precautionary measures. The relative novelty of technology and workflows for direct MRI-guided procedures requires consideration of safe practice recommendations, including those pertaining to infection control and magnet safety issues. This article proposes a framework of safe practice recommendations designed for assessing readiness and optimization of MRI-guided neurosurgical interventions in the diagnostic MRI suite in an effort to mitigate patient risk. The framework is based on existing clinical evidence, recommendations, and guidelines related to infection control and prevention, health care-associated infections, and magnet safety, as well as the clinical and practical experience of neurosurgeons utilizing this technology. © 2017 American Society for Healthcare Risk Management of the American Hospital Association.

  20. Model-based security testing


    Schieferdecker, Ina; Großmann, Jürgen; Schneider, Martin


    Security testing aims at validating software system requirements related to security properties like confidentiality, integrity, authentication, authorization, availability, and non-repudiation. Although security testing techniques are available for many years, there has been little approaches that allow for specification of test cases at a higher level of abstraction, for enabling guidance on test identification and specification as well as for automated test generation. Model-based security...

  1. Self-organized Criticality and Synchronization in a Pulse-coupled Integrate-and-Fire Neuron Model Based on Small World Networks

    International Nuclear Information System (INIS)

    Lin Min; Chen Tianlun


    A lattice model for a set of pulse-coupled integrate-and-fire neurons with small world structure is introduced. We find that our model displays the power-law behavior accompanied with the large-scale synchronized activities among the units. And the different connectivity topologies lead to different behaviors in models of integrate-and-fire neurons.

  2. fMRI for mapping language networks in neurosurgical cases

    International Nuclear Information System (INIS)

    Gupta, Santosh S


    Evaluating language has been a long-standing application in functional magnetic resonance imaging (fMRI) studies, both in research and clinical circumstances, and still provides challenges. Localization of eloquent areas is important in neurosurgical cases, so that there is least possible damage to these areas during surgery, maintaining their function postoperatively, therefore providing good quality of life to the patient. Preoperative fMRI study is a non-invasive tool to localize the eloquent areas, including language, with other traditional methods generally used being invasive and at times perilous. In this article, we describe methods and various paradigms to study the language areas, in clinical neurosurgical cases, along with illustrations of cases from our institute

  3. Readability and quality of wikipedia pages on neurosurgical topics. (United States)

    Modiri, Omeed; Guha, Daipayan; Alotaibi, Naif M; Ibrahim, George M; Lipsman, Nir; Fallah, Aria


    Wikipedia is the largest online encyclopedia with over 40 million articles, and generating 500 million visits per month. The aim of this study is to assess the readability and quality of Wikipedia pages on neurosurgical related topics. We selected the neurosurgical related Wikipedia pages based on the series of online patient information articles that are published by the American Association of Neurological Surgeons (AANS). We assessed readability of Wikipedia pages using five different readability scales (Flesch Reading Ease, Flesch Kincaid Grade Level, Gunning Fog Index, SMOG) Grade level, and Coleman-Liau Index). We used the Center for Disease Control (CDC) Clear Communication Index as well as the DISCERN Instrument to evaluate the quality of each Wikipedia article. We identified a total of fifty-five Wikipedia articles that corresponded with patient information articles published by the AANS. This constitutes 77.46% of the AANS topics. The mean Flesch Kincaid reading ease score for all of the Wikipedia articles we analyzed is 31.10, which indicates that a college-level education is necessary to understand them. In comparison to the readability analysis for the AANS articles, the Wikipedia articles were more difficult to read across every scale. None of the Wikipedia articles meet the CDC criterion for clear communications. Our analyses demonstrated that Wikipedia articles related to neurosurgical topics are associated with higher grade levels for reading and also below the expected levels of clear communications for patients. Collaborative efforts from the neurosurgical community are needed to enhance the readability and quality of Wikipedia pages related to neurosurgery. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Current situation and consideration of training base hospitals for residents of neurosurgical specialization in China

    Directory of Open Access Journals (Sweden)

    Feng-zeng JIAN


    Full Text Available Resident training of neurosurgical specialization will be tried and carried out in all over China. From the point of view of training base hospitals, a majority of 3A level hospitals have sufficient patients and good equipments which will ensure the success of training process; however, division of subspecialty, teaching motivation and teaching method still have a great potential to improve. In order to establish and improve training bases for residents of specialization, supervision from national administrative department should be strengthened; professional society also plays an important role in standardizing and controlling the training quality. Considering our nation's situation, integration of postgraduate education and resident training is worth of discussion. DOI: 10.3969/j.issn.1672-6731.2015.07.015

  5. [Dynamics of lagophthalmos depending on facial nerve repair and its intraoperative monitoring in neurosurgical patients]. (United States)

    Tabachnikova, T V; Serova, N K; Shimansky, V N


    Over 200 patients with acoustic neuromas and over 100 patients with posterior cranial fossa meningiomas are annually operated on at the N.N. Burdenko Neurosurgical Institute. Intraoperative monitoring of the facial nerve function is used in most patients with tumors of the posterior cranial fossa to identify the facial nerve in the surgical wound. If the anatomical integrity of the facial nerve in the cranial cavity cannot be retained, facial nerve repair is performed to restore the facial muscle function. Intraoperative electrical stimulation of the facial nerve has a great prognostic significance to evaluate the dynamics of lagophthalmos in the late postoperative period and to select the proper method for lagophthalmos correction. When the facial nerve was reinnervated by the descending branch or trunk of the hypoglossal nerve, sufficient eyelid closure was observed only in 3 patients out of 17.

  6. Neurosurgical management in children with bleeding diathesis: auditing neurological outcome. (United States)

    Zakaria, Zaitun; Kaliaperumal, Chandrasekaran; Crimmins, Darach; Caird, John


    OBJECTIVE The aim of this study was to assess the outcome of neurosurgical treatment in children with bleeding diathesis and also to evaluate the current management plan applied in the authors' service. METHODS The authors retrospectively analyzed all cases in which neurosurgical procedures were performed in pediatric patients presenting with intracranial hematoma due to an underlying bleeding tendency over a 5-year period at their institution. They evaluated the patients' neurological symptoms from the initial referral, hematological abnormalities, surgical treatment, neurological outcome, and scores on the Pediatric Glasgow Outcome Scale-Extended (GOS-E Peds) obtained 1 year after the last operation. RESULTS Five patients with a bleeding diathesis who underwent surgery for intracranial hematoma were identified; the diagnosis was hemophilia A in 3 cases, idiopathic thrombocytopenic purpura in 1 case, and severe aplastic anemia in 1 case. Intracerebral hematoma (ICH) (n = 4) and acute subdural hematoma (n = 1) were confirmed on radiological investigations. In 2 of the 4 patients with ICH, the diagnosis of bleeding diathesis was made for the first time on presentation. Four patients (all male) were younger than 2 years; the patient with severe aplastic anemia and spontaneous ICH was 15 years old and female. The duration of symptoms varied from 24 hours to 5 days. Neurological examination at 1 year's follow-up showed complete recovery (GOS-E Peds score of 1) in 3 cases and mild weakness (GOS-E Peds score of 2) in 2 cases. CONCLUSIONS Neurosurgical management of patients with bleeding diathesis should be carried out in a tertiary-care setting with multidisciplinary team management, including members with expertise in neuroimaging and hematology, in addition to neurosurgery. Early diagnosis and prompt treatment of a bleeding diathesis is crucial for full neurological recovery.

  7. Machine Learning and Neurosurgical Outcome Prediction: A Systematic Review. (United States)

    Senders, Joeky T; Staples, Patrick C; Karhade, Aditya V; Zaki, Mark M; Gormley, William B; Broekman, Marike L D; Smith, Timothy R; Arnaout, Omar


    Accurate measurement of surgical outcomes is highly desirable to optimize surgical decision-making. An important element of surgical decision making is identification of the patient cohort that will benefit from surgery before the intervention. Machine learning (ML) enables computers to learn from previous data to make accurate predictions on new data. In this systematic review, we evaluate the potential of ML for neurosurgical outcome prediction. A systematic search in the PubMed and Embase databases was performed to identify all potential relevant studies up to January 1, 2017. Thirty studies were identified that evaluated ML algorithms used as prediction models for survival, recurrence, symptom improvement, and adverse events in patients undergoing surgery for epilepsy, brain tumor, spinal lesions, neurovascular disease, movement disorders, traumatic brain injury, and hydrocephalus. Depending on the specific prediction task evaluated and the type of input features included, ML models predicted outcomes after neurosurgery with a median accuracy and area under the receiver operating curve of 94.5% and 0.83, respectively. Compared with logistic regression, ML models performed significantly better and showed a median absolute improvement in accuracy and area under the receiver operating curve of 15% and 0.06, respectively. Some studies also demonstrated a better performance in ML models compared with established prognostic indices and clinical experts. In the research setting, ML has been studied extensively, demonstrating an excellent performance in outcome prediction for a wide range of neurosurgical conditions. However, future studies should investigate how ML can be implemented as a practical tool supporting neurosurgical care. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Virtual reality simulator: demonstrated use in neurosurgical oncology. (United States)

    Clarke, David B; D'Arcy, Ryan C N; Delorme, Sebastien; Laroche, Denis; Godin, Guy; Hajra, Sujoy Ghosh; Brooks, Rupert; DiRaddo, Robert


    The overriding importance of patient safety, the complexity of surgical techniques, and the challenges associated with teaching surgical trainees in the operating room are all factors driving the need for innovative surgical simulation technologies. Despite these issues, widespread use of virtual reality simulation technology in surgery has not been fully implemented, largely because of the technical complexities in developing clinically relevant and useful models. This article describes the successful use of the NeuroTouch neurosurgical simulator in the resection of a left frontal meningioma. The widespread application of surgical simulation technology has the potential to decrease surgical risk, improve operating room efficiency, and fundamentally change surgical training.

  9. [Antigravity suit used for neurosurgical operations in sitting position]. (United States)

    Szpiro-Zurkowska, A; Milczarek, Z; Marchel, A; Jagielski, J


    The aviator's antigravity suit (G-suit) was used for 40 operations on neurosurgical patients operated on in sitting position. The G-suit was filled with air to 0.2 atmosphere (20 kPa) pressure in 26 cases, and 0.3 atm. (30 kPa) in 14 cases. In all cases G-suit filling was followed by central venous pressure rise and mean arterial pressure rise. Venous air embolism was found in 5 (12.5%) patients. No other complications connected with the use of G-suit were observed.

  10. Energy saving analysis and management modeling based on index decomposition analysis integrated energy saving potential method: Application to complex chemical processes

    International Nuclear Information System (INIS)

    Geng, Zhiqiang; Gao, Huachao; Wang, Yanqing; Han, Yongming; Zhu, Qunxiong


    Highlights: • The integrated framework that combines IDA with energy-saving potential method is proposed. • Energy saving analysis and management framework of complex chemical processes is obtained. • This proposed method is efficient in energy optimization and carbon emissions of complex chemical processes. - Abstract: Energy saving and management of complex chemical processes play a crucial role in the sustainable development procedure. In order to analyze the effect of the technology, management level, and production structure having on energy efficiency and energy saving potential, this paper proposed a novel integrated framework that combines index decomposition analysis (IDA) with energy saving potential method. The IDA method can obtain the level of energy activity, energy hierarchy and energy intensity effectively based on data-drive to reflect the impact of energy usage. The energy saving potential method can verify the correctness of the improvement direction proposed by the IDA method. Meanwhile, energy efficiency improvement, energy consumption reduction and energy savings can be visually discovered by the proposed framework. The demonstration analysis of ethylene production has verified the practicality of the proposed method. Moreover, we can obtain the corresponding improvement for the ethylene production based on the demonstration analysis. The energy efficiency index and the energy saving potential of these worst months can be increased by 6.7% and 7.4%, respectively. And the carbon emissions can be reduced by 7.4–8.2%.

  11. Integrated Sensing & Controls for Coal Gasification - Development of Model-Based Controls for GE's Gasifier & Syngas Cooler. Topical Rerport for Phase III

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Aditya


    This Topical Report for the final Phase III of the program summarizes the results from the Task 3 of the program. In this task, the separately designed extended Kalman Filter (EKF) and model predictive controls (MPC) with ideal sensing, developed in Phase II, were integrated to achieve the overall sensing and control system for the gasification section of an IGCC plant. The EKF and MPC algorithms were updated and re-tuned to achieve closed-loop system stability as well as good steady-state and transient control response. In particular, the performance of the integrated EKF and MPC solution was tested extensively through multiple simulation studies to achieve improved steady-state as well as transient performance, with coal as well as coal-petcoke blended fuel, in the presence of unknown modeling errors as well as sensor errors (noise and bias). The simulation studies demonstrated significant improvements in steady state and transient operation performance, similar to that achieved by MPC with ideal sensors in Phase II of the program.

  12. Prospective review of a single center's general pediatric neurosurgical intraoperative and postoperative complication rates

    NARCIS (Netherlands)

    Lindert, E.J. van; Delye, H.H.; Leonardo, J.


    OBJECT: The authors conducted a study to compare the complication rate (CR) of pediatric neurosurgical procedures in a general neurosurgery department to the CRs that are reported in the literature and to establish a baseline of CR for further targeted improvement of quality neurosurgical care.

  13. Hybrid Microscopic-Endoscopic Surgery for Craniopharyngioma in Neurosurgical Suite: Technical Notes. (United States)

    Ichikawa, Tomotsugu; Otani, Yoshihiro; Ishida, Joji; Fujii, Kentaro; Kurozumi, Kazuhiko; Ono, Shigeki; Date, Isao


    The best chance of curing craniopharyngioma is achieved by microsurgical total resection; however, its location adjacent to critical structures hinders complete resection without neurologic deterioration. Unrecognized residual tumor within microscopic blind spots might result in tumor recurrences. To improve outcomes, new techniques are necessary to visualize tissue within these blind spots. We examined the success of hybrid microscopic-endoscopic neurosurgery for craniopharyngioma in a neurosurgical suite. Four children with craniopharyngiomas underwent microscopic resection. When the neurosurgeon was confident that most of the visible tumor was removed but was suspicious of residual tumor within the blind spot, he or she used an integrated endoscope-holder system to inspect and remove any residual tumor. Two ceiling monitors were mounted side by side in front of the surgeon to display both microscopic and endoscopic views and to view both monitors simultaneously. Surgery was performed in all patients via the frontobasal interhemispheric approach. Residual tumors were observed in the sella (2 patients), on the ventral surface of the chiasm and optic nerve (1 patient), and in the third ventricle (1 patient) and were resected to achieve total resection. Postoperatively, visual function was improved in 2 patients and none exhibited deterioration related to the surgery. Simultaneous microscopic and endoscopic observation with the use of dual monitors in a neurosurgical suite was ergonomically optimal for the surgeon to perform microsurgical procedures and to avoid traumatizing surrounding vessels or neural tissues. Hybrid microscopic-endoscopic neurosurgery may contribute to safe, less-invasive, and maximal resection to achieve better prognosis in children with craniopharyngioma. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Maria Auxiliadora Hospital in Lima, Peru as a model for neurosurgical outreach to international charity hospitals. (United States)

    Hayden, Melanie G; Hughes, Samuel; Hahn, Edward J; Aryan, Henry E; Levy, Michael L; Jandial, Rahul


    A myriad of geopolitical and financial obstacles have kept modern neurosurgery from effectively reaching the citizens of the developing world. Targeted neurosurgical outreach by academic neurosurgeons to equip neurosurgical operating theaters and train local neurosurgeons is one method to efficiently and cost effectively improve sustainable care provided by international charity hospitals. The International Neurosurgical Children's Association (INCA) effectively improved the available neurosurgical care in the Maria Auxiliadora Hospital of Lima, Peru through the advancement of local specialist education and training. Neurosurgical equipment and training were provided for the local neurosurgeons by a mission team from the University of California at San Diego. At the end of 3 years, with one intensive week trip per year, the host neurosurgeons were proficiently and independently applying microsurgical techniques to previously performed operations, and performing newly learned operations such as neuroendoscopy and minimally invasive neurosurgery. Our experiences may serve as a successful template for the execution of other small scale, sustainable neurosurgery missions worldwide.

  15. Neurosurgical strategies for Gilles de la Tourette’s syndrome

    Directory of Open Access Journals (Sweden)

    Karim Mukhida


    Full Text Available Karim Mukhida1,2, Matthew Bishop2, Murray Hong2, Ivar Mendez21Division of Neurosurgery, University of Toronto, Toronto, Ontario, Canada; 2Departments, of Anatomy and Neurobiology and Surgery (Neurosurgery, Dalhousie University, Halifax, Nova Scotia, CanadaAbstract: Tourette’s syndrome (TS is a neurological disorder characterized by motor and vocal tics that typically begin in childhood and often are accompanied by psychiatric comorbidities. Symptoms of TS may be socially disabling and cause secondary medical complications. Pharmacological therapies remain the mainstay of symptom management. For the subset of patients in whom TS symptoms are medically recalcitrant and do not dissipate by adulthood, neurosurgery may offer an alternative treatment strategy. Greater understanding of the neuroanatomic and pathophysiologic basis of TS has facilitated the development of surgical procedures that aim to ameliorate TS symptoms by lesions or deep brain stimulation of cerebral structures. Herein, the rationale for the surgical management of TS is discussed and neurosurgical experiences since the 1960s are reviewed. The necessity for neurosurgical strategies to be performed with appropriate ethical considerations is highlighted.Keywords: tourette’s syndrome, neurosurgery, deep brain stimulation, thalamus

  16. Shape memory alloys: metallurgy, biocompatibility, and biomechanics for neurosurgical applications. (United States)

    Hoh, Daniel J; Hoh, Brian L; Amar, Arun P; Wang, Michael Y


    SHAPE MEMORY ALLOYS possess distinct dynamic properties with particular applications in neurosurgery. Because of their unique physical characteristics, these materials are finding increasing application where resiliency, conformation, and actuation are needed. Nitinol, the most frequently manufactured shape memory alloy, responds to thermal and mechanical stimuli with remarkable mechanical properties such as shape memory effect, super-elasticity, and high damping capacity. Nitinol has found particular use in the biomedical community because of its excellent fatigue resistance and biocompatibility, with special interest in neurosurgical applications. The properties of nitinol and its diffusionless phase transformations contribute to these unique mechanical capabilities. The features of nitinol, particularly its shape memory effect, super-elasticity, damping capacity, as well as its biocompatibility and biomechanics are discussed herein. Current and future applications of nitinol and other shape memory alloys in endovascular, spinal, and minimally invasive neurosurgery are introduced. An understanding of the metallurgic properties of nitinol provides a foundation for further exploration of its use in neurosurgical implant design.

  17. Integrating process safety with molecular modeling-based risk assessment of chemicals within the REACH regulatory framework: benefits and future challenges. (United States)

    Lewis, Amanda; Kazantzis, Nikolaos; Fishtik, Ilie; Wilcox, Jennifer


    Registration, evaluation and authorization of chemicals (REACH) represents a recent regulatory initiative by the European union commission to protect human health and the environment from potentially hazardous chemicals. Under REACH, all stakeholders must submit (thermo)physical, thermochemical, and toxicological data for certain chemicals. The commission's impact assessment studies estimate that the costs of REACH will be approximately 3-5 billion Euros. The present study advocates the systematic incorporation of computational chemistry and computer-assisted chemical risk assessment methods into REACH to reduce regulatory compliance costs. Currently powerful computer-aided ab initio techniques can be used to generate predictions of key properties of broad classes of chemicals, without resorting to costly experimentation and potentially hazardous testing. These data could be integrated into a centralized IT decision and compliance support system, and stored in a retrievable, easily communicable manner should new regulatory and/or production requirements necessitate the introduction of different uses of chemicals under different conditions. For illustration purposes, ab initio calculations are performed on heterocyclic nitrogen-containing compounds which currently serve as high energy density materials in the chemical industry. Since investigations of these compounds are still in their infancy, stability studies are imperative regarding their safe handling and storage, as well as registration under REACH.

  18. Integrating process safety with molecular modeling-based risk assessment of chemicals within the REACH regulatory framework: Benefits and future challenges

    International Nuclear Information System (INIS)

    Lewis, Amanda; Kazantzis, Nikolaos; Fishtik, Ilie; Wilcox, Jennifer


    Registration, evaluation and authorization of chemicals (REACH) represents a recent regulatory initiative by the European union commission to protect human health and the environment from potentially hazardous chemicals. Under REACH, all stakeholders must submit (thermo)physical, thermochemical, and toxicological data for certain chemicals. The commission's impact assessment studies estimate that the costs of REACH will be approximately 3-5 billion Euros. The present study advocates the systematic incorporation of computational chemistry and computer-assisted chemical risk assessment methods into REACH to reduce regulatory compliance costs. Currently powerful computer-aided ab initio techniques can be used to generate predictions of key properties of broad classes of chemicals, without resorting to costly experimentation and potentially hazardous testing. These data could be integrated into a centralized IT decision and compliance support system, and stored in a retrievable, easily communicable manner should new regulatory and/or production requirements necessitate the introduction of different uses of chemicals under different conditions. For illustration purposes, ab initio calculations are performed on heterocyclic nitrogen-containing compounds which currently serve as high energy density materials in the chemical industry. Since investigations of these compounds are still in their infancy, stability studies are imperative regarding their safe handling and storage, as well as registration under REACH

  19. Authentic scientific data collection in support of an integrative model-based class: A framework for student engagement in the classroom (United States)

    Sorensen, A. E.; Dauer, J. M.; Corral, L.; Fontaine, J. J.


    A core component of public scientific literacy, and thereby informed decision-making, is the ability of individuals to reason about complex systems. In response to students having difficulty learning about complex systems, educational research suggests that conceptual representations, or mental models, may help orient student thinking. Mental models provide a framework to support students in organizing and developing ideas. The PMC-2E model is a productive tool in teaching ideas of modeling complex systems in the classroom because the conceptual representation framework allows for self-directed learning where students can externalize systems thinking. Beyond mental models, recent work emphasizes the importance of facilitating integration of authentic science into the formal classroom. To align these ideas, a university class was developed around the theme of carnivore ecology, founded on PMC-2E framework and authentic scientific data collection. Students were asked to develop a protocol, collect, and analyze data around a scientific question in partnership with a scientist, and then use data to inform their own learning about the system through the mental model process. We identified two beneficial outcomes (1) scientific data is collected to address real scientific questions at a larger scale and (2) positive outcomes for student learning and views of science. After participating in the class, students report enjoying class structure, increased support for public understanding of science, and shifts in nature of science and interest in pursuing science metrics on post-assessments. Further work is ongoing investigating the linkages between engaging in authentic scientific practices that inform student mental models, and how it might promote students' systems-thinking skills, implications for student views of nature of science, and development of student epistemic practices.

  20. The economics of renewable electricity market integration. An empirical and model-based analysis of regulatory frameworks and their impacts on the power market

    Energy Technology Data Exchange (ETDEWEB)

    Nicolosi, Marco


    participate in the reserve power market. In general, the results show that if the flexibility of one system component is reduced, the flexibility values of other system components increase, which suggests a careful, integrated and long-term oriented policy setting.

  1. The genesis of neurosurgery and the evolution of the neurosurgical operative environment: part II--concepts for future development, 2003 and beyond. (United States)

    Liu, Charles Y; Spicer, Mark; Apuzzo, Michael L J


    The future development of the neurosurgical operative environment is driven principally by concurrent development in science and technology. In the new millennium, these developments are taking on a Jules Verne quality, with the ability to construct and manipulate the human organism and its surroundings at the level of atoms and molecules seemingly at hand. Thus, an examination of currents in technology advancement from the neurosurgical perspective can provide insight into the evolution of the neurosurgical operative environment. In the future, the optimal design solution for the operative environment requirements of specialized neurosurgery may take the form of composites of venues that are currently mutually distinct. Advances in microfabrication technology and laser optical manipulators are expanding the scope and role of robotics, with novel opportunities for bionic integration. Assimilation of biosensor technology into the operative environment promises to provide neurosurgeons of the future with a vastly expanded set of physiological data, which will require concurrent simplification and optimization of analysis and presentation schemes to facilitate practical usefulness. Nanotechnology derivatives are shattering the maximum limits of resolution and magnification allowed by conventional microscopes. Furthermore, quantum computing and molecular electronics promise to greatly enhance computational power, allowing the emerging reality of simulation and virtual neurosurgery for rehearsal and training purposes. Progressive minimalism is evident throughout, leading ultimately to a paradigm shift as the nanoscale is approached. At the interface between the old and new technological paradigms, issues related to integration may dictate the ultimate emergence of the products of the new paradigm. Once initiated, however, history suggests that the process of change will proceed rapidly and dramatically, with the ultimate neurosurgical operative environment of the future

  2. Model-Based Security Testing

    Directory of Open Access Journals (Sweden)

    Ina Schieferdecker


    Full Text Available Security testing aims at validating software system requirements related to security properties like confidentiality, integrity, authentication, authorization, availability, and non-repudiation. Although security testing techniques are available for many years, there has been little approaches that allow for specification of test cases at a higher level of abstraction, for enabling guidance on test identification and specification as well as for automated test generation. Model-based security testing (MBST is a relatively new field and especially dedicated to the systematic and efficient specification and documentation of security test objectives, security test cases and test suites, as well as to their automated or semi-automated generation. In particular, the combination of security modelling and test generation approaches is still a challenge in research and of high interest for industrial applications. MBST includes e.g. security functional testing, model-based fuzzing, risk- and threat-oriented testing, and the usage of security test patterns. This paper provides a survey on MBST techniques and the related models as well as samples of new methods and tools that are under development in the European ITEA2-project DIAMONDS.

  3. Neurosurgical management of L-asparaginase induced haemorrhagic stroke.

    LENUS (Irish Health Repository)

    Ogbodo, Elisha


    The authors describe a case of L-asparaginase induced intracranial thrombosis and subsequent haemorrhage in a newly diagnosed 30-year-old man with acute lymphoblastic leukaemia who was successfully managed by surgical intervention. At presentation, he had a Glasgow Coma Score of 7\\/15, was aphasic and had dense right hemiplegia. Neuroimaging revealed an acute anterior left middle cerebral artery infarct with parenchymal haemorrhagic conversion, mass effect and subfalcine herniation. He subsequently underwent left frontal craniotomy and evacuation of large frontal haematoma and decompressive craniectomy for cerebral oedema. Six months postoperatively he underwent titanium cranioplasty. He had made good clinical recovery and is currently mobilising independently with mild occasional episodes of expressive dysphasia, difficulty with fine motor movement on the right side, and has remained seizure free. This is the first documented case of L-asparaginase induced haemorrhagic stroke managed by neurosurgical intervention. The authors emphasise the possible role of surgery in managing chemotherapy induced intracranial complications.

  4. Management of post-neurosurgical meningitis: narrative review. (United States)

    Hussein, K; Bitterman, R; Shofty, B; Paul, M; Neuberger, A


    Infections complicating neurosurgery pose unacceptable mortality and morbidity. To summarize what is known about the epidemiology, diagnosis and treatment of post-neurosurgical meningitis (PNM). PubMed, references of identified studies and reviews, and personal experience when evidence was lacking. The incidence and pathogen distribution of PNM is highly variable. A shift towards Gram-negative bacteria has been observed with use of antibiotic prophylaxis and antibiotic-coated devices directed mainly against Gram-positive bacteria. However, knowledge of the local epidemiology is necessary to treat PNM. The diagnosis of PNM is difficult because, unlike community-acquired meningitis, symptoms are less specific; patients are ill at baseline and many neurosurgical conditions mimic meningitis and cause cerebrospinal fluid (CSF) abnormalities. Pivotal CSF findings for diagnosis of PNM are the CSF glucose, CSF lactate and Gram stain. CSF leucocyte counts are not specific in PNM. Current diagnostic capabilities leave a non-negligible category of patients with microbiologically negative, uncertain diagnosis of PNM. There is no high-quality evidence on several cardinal issues in PNM management, including the effectiveness of intraventricular or intrathecal (IV/IT) antibiotics, effectiveness of dual antibiotic therapy for multidrug-resistant Gram-negative bacteria; clinical benefit of routine therapeutic drug monitoring; and safest timing of shunt replacement. Some data point to a potential benefit of IV/IT antibiotic treatment, mainly for PNM caused by carbapenem-resistant Gram-negative bacteria. Carbapenem-colistin combination therapy is suggested for PNM caused by carbapenem-resistant Gram-negative bacteria with a carbapenem MIC ≤8 mg/L. Guiding the optimal management of PNM will necessitate collaborative multicentre efforts and unique study designs. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights

  5. Shadow of Buddhism and Shintoism in neurosurgical practice in Japan. (United States)

    Ohta, T


    In Japan, almost all culture and civilization were introduced from abroad; in the past from China and now from U.S. and European countries, owing to her geographical features circumscribed by oceans and separated from the continents. Neurosurgical science and practice have been received in the same way as other activities. However, there are some exceptions such as organ transplantation from the brain dead and brain-dock, which means a brain check-up system of asymptomatic brain diseases. Reasons why these are practised or not in Japan are considered from the viewpoint of Buddhism and Shintoism. If our special practises could appeal to people in other countries, our neurosurgical philosophy might become widespread and welcome worldwide. Organ transplantations from brain dead have routinely been performed in many countries, while only 37 cases have been executed in Japan, after the Japanese government accepted its application in 1997. In contrast, brain-dock is widely practised without any national insurance systems, while this is rarely practised in other countries. It seems to me that Buddhism and Shintoism have influenced on these special situations, due to extreme fear and impurity of the dead body and a way of comprehending the oneness of body and mind, and also deep concern for the impact of their diseases to their families rather than for themselves. We neurosurgeons should realize that our profession is directly related to ultimate human sufferings such as aging, disease, and death, as pointed out by Gautama Buddha. We are in fact in a position to study the real way for resolution of the human sufferings, mentally and physically. Based on our experiences, the foundation of a new academic discipline like "cultural medical science" should urgently be considered in all parts of the world and in light of individual cultural, economical, geographical, and population problems.

  6. Model Based Temporal Reasoning (United States)

    Rabin, Marla J.; Spinrad, Paul R.; Fall, Thomas C.


    Systems that assess the real world must cope with evidence that is uncertain, ambiguous, and spread over time. Typically, the most important function of an assessment system is to identify when activities are occurring that are unusual or unanticipated. Model based temporal reasoning addresses both of these requirements. The differences among temporal reasoning schemes lies in the methods used to avoid computational intractability. If we had n pieces of data and we wanted to examine how they were related, the worst case would be where we had to examine every subset of these points to see if that subset satisfied the relations. This would be 2n, which is intractable. Models compress this; if several data points are all compatible with a model, then that model represents all those data points. Data points are then considered related if they lie within the same model or if they lie in models that are related. Models thus address the intractability problem. They also address the problem of determining unusual activities if the data do not agree with models that are indicated by earlier data then something out of the norm is taking place. The models can summarize what we know up to that time, so when they are not predicting correctly, either something unusual is happening or we need to revise our models. The model based reasoner developed at Advanced Decision Systems is thus both intuitive and powerful. It is currently being used on one operational system and several prototype systems. It has enough power to be used in domains spanning the spectrum from manufacturing engineering and project management to low-intensity conflict and strategic assessment.

  7. Bimanual Psychomotor Performance in Neurosurgical Resident Applicants Assessed Using NeuroTouch, a Virtual Reality Simulator. (United States)

    Winkler-Schwartz, Alexander; Bajunaid, Khalid; Mullah, Muhammad A S; Marwa, Ibrahim; Alotaibi, Fahad E; Fares, Jawad; Baggiani, Marta; Azarnoush, Hamed; Zharni, Gmaan Al; Christie, Sommer; Sabbagh, Abdulrahman J; Werthner, Penny; Del Maestro, Rolando F

    Current selection methods for neurosurgical residents fail to include objective measurements of bimanual psychomotor performance. Advancements in computer-based simulation provide opportunities to assess cognitive and psychomotor skills in surgically naive populations during complex simulated neurosurgical tasks in risk-free environments. This pilot study was designed to answer 3 questions: (1) What are the differences in bimanual psychomotor performance among neurosurgical residency applicants using NeuroTouch? (2) Are there exceptionally skilled medical students in the applicant cohort? and (3) Is there an influence of previous surgical exposure on surgical performance? Participants were instructed to remove 3 simulated brain tumors with identical visual appearance, stiffness, and random bleeding points. Validated tier 1, tier 2, and advanced tier 2 metrics were used to assess bimanual psychomotor performance. Demographic data included weeks of neurosurgical elective and prior operative exposure. This pilot study was carried out at the McGill Neurosurgical Simulation Research and Training Center immediately following neurosurgical residency interviews at McGill University, Montreal, Canada. All 17 medical students interviewed were asked to participate, of which 16 agreed. Performances were clustered in definable top, middle, and bottom groups with significant differences for all metrics. Increased time spent playing music, increased applicant self-evaluated technical skills, high self-ratings of confidence, and increased skin closures statistically influenced performance on univariate analysis. A trend for both self-rated increased operating room confidence and increased weeks of neurosurgical exposure to increased blood loss was seen in multivariate analysis. Simulation technology identifies neurosurgical residency applicants with differing levels of technical ability. These results provide information for studies being developed for longitudinal studies on the

  8. Virtual reality in neurosurgical education: part-task ventriculostomy simulation with dynamic visual and haptic feedback. (United States)

    Lemole, G Michael; Banerjee, P Pat; Luciano, Cristian; Neckrysh, Sergey; Charbel, Fady T


    Mastery of the neurosurgical skill set involves many hours of supervised intraoperative training. Convergence of political, economic, and social forces has limited neurosurgical resident operative exposure. There is need to develop realistic neurosurgical simulations that reproduce the operative experience, unrestricted by time and patient safety constraints. Computer-based, virtual reality platforms offer just such a possibility. The combination of virtual reality with dynamic, three-dimensional stereoscopic visualization, and haptic feedback technologies makes realistic procedural simulation possible. Most neurosurgical procedures can be conceptualized and segmented into critical task components, which can be simulated independently or in conjunction with other modules to recreate the experience of a complex neurosurgical procedure. We use the ImmersiveTouch (ImmersiveTouch, Inc., Chicago, IL) virtual reality platform, developed at the University of Illinois at Chicago, to simulate the task of ventriculostomy catheter placement as a proof-of-concept. Computed tomographic data are used to create a virtual anatomic volume. Haptic feedback offers simulated resistance and relaxation with passage of a virtual three-dimensional ventriculostomy catheter through the brain parenchyma into the ventricle. A dynamic three-dimensional graphical interface renders changing visual perspective as the user's head moves. The simulation platform was found to have realistic visual, tactile, and handling characteristics, as assessed by neurosurgical faculty, residents, and medical students. We have developed a realistic, haptics-based virtual reality simulator for neurosurgical education. Our first module recreates a critical component of the ventriculostomy placement task. This approach to task simulation can be assembled in a modular manner to reproduce entire neurosurgical procedures.

  9. Telemedicine using an image transfer system in the treatment of neurosurgical emergent cases

    International Nuclear Information System (INIS)

    Saito, Atsushi; Numagami, Yoshihiro; Kamiyama, Hironaga; Furuno, Yuuichi; Nishimura, Shinjitsu; Nishijima, Michiharu


    Our department is located in the Tsugaru district, which is famous for heavy snow fall, and the small number of neurosurgeon centers in the urban areas leads to an inadequate distribution of neurosurgeons for patients in this region. Such geographical and social constraints have made it difficult to offer sufficient neurosurgical care to all patients in the region. We describe the usefulness of a telemedicine triage system using an image transfer system in the treatment of neurosurgical emergent cases. Image transfer systems have been installed at our hospital and 11 regional hospitals in the Tsugaru district, and have been utilized for teleconsultation regarding neurosurgical patients via transferred computed tomography images since 1989. Consultations regarding 2,858 cases were directed to our department between 1989 and 2006, including 1,615 cases of stroke, 869 cases of head trauma, 97 cases of brain tumor, and 277 cases with other disorders. 84% of subarachnoid hemorrhage cases and 22% of head trauma cases needed emergent transfer. The state of consciousness in intracerebral hemorrhage, and the state of consciousness and time of consultation in head trauma were statistically significant factors for emergent transfer. The presert telemedicine triage system was useful for ensuring correct diagnosis and appropriate primary neurosurgical care in the regional hospitals without neurosurgical units, resulting in a reinforcement of the relationships among the regional hospitals and the efficient transfer of emergent neurosurgical patients. (author)

  10. Feasibility of simultaneous sodium fluorescein and indocyanine green injection in neurosurgical procedures. (United States)

    Acerbi, F; Restelli, F; Broggi, M; Schiariti, M; Ferroli, P


    The objective of this study is to assess the feasibility of simultaneous Sodium Fluorescein (SF) and Indocyanine Green (ICG) injection during neurosurgical procedures. Three patients harboring a high-grade glioma (HGG) were retrospectively identified in the surgical database of the Neurosurgical Unit 2 at the Foundation IRCCS Istituto Neurologico C. Besta in Milan, by having received intraoperatively both SF for tumor resection and ICG for vasculature angiographic studies in the same surgical procedure. We identified 2 males and 1 female (age range 25-60). Lesions were located in the left temporo-polar area and hippocampus (1 case), right superior frontal gyrus (1 case), left supplementary motor area (1 case). All the three lesions showed Magnetic Resonance Imaging (MRI) characteristics of HGG and, for this reason, in all patients a fluorescein-guided tumor removal was proposed. In the same surgical procedure ICG videoangiography was considered necessary in order to study arterial and venous vasculature, given by the strict relation of the tumor with an unexpected Posterior Communicating Artery (PComA) aneurysm in one case and with cortical drainage veins complexes in the other two cases. In all cases a microscope equipped with both YELLOW560 and IR800 integrated filters (Pentero 900, Carl Zeiss, Oberkorchen, Germany) was used. Fluorescein was i.v. injected at a dose of 5mg/kg immediately after patient intubation. ICG was i.v. injected in bolus on demand of the operating surgeon at a dose of 12.5mg. No side-effects related to simultaneous injection of SF and ICG were identified. In all three cases, the use of SF allowed to better visualize the tumor areas during surgical removal, thus leading to a radical resection until no macroscopic appearance of residual tumor mass and no fluorescence was visible in the surgical cavity. ICG videoangiography confirmed the patency of branches of internal carotid artery after clipping of an unexpected small PComA aneurysm found

  11. Demystifying process mapping: a key step in neurosurgical quality improvement initiatives. (United States)

    McLaughlin, Nancy; Rodstein, Jennifer; Burke, Michael A; Martin, Neil A


    Reliable delivery of optimal care can be challenging for care providers. Health care leaders have integrated various business tools to assist them and their teams in ensuring consistent delivery of safe and top-quality care. The cornerstone to all quality improvement strategies is the detailed understanding of the current state of a process, captured by process mapping. Process mapping empowers caregivers to audit how they are currently delivering care to subsequently strategically plan improvement initiatives. As a community, neurosurgery has clearly shown dedication to enhancing patient safety and delivering quality care. A care redesign strategy named NERVS (Neurosurgery Enhanced Recovery after surgery, Value, and Safety) is currently being developed and piloted within our department. Through this initiative, a multidisciplinary team led by a clinician neurosurgeon has process mapped the way care is currently being delivered throughout the entire episode of care. Neurosurgeons are becoming leaders in quality programs, and their education on the quality improvement strategies and tools is essential. The authors present a comprehensive review of process mapping, demystifying its planning, its building, and its analysis. The particularities of using process maps, initially a business tool, in the health care arena are discussed, and their specific use in an academic neurosurgical department is presented.

  12. Advanced approach for intraoperative MRI guidance and potential benefit for neurosurgical applications. (United States)

    Busse, Harald; Schmitgen, Arno; Trantakis, Christos; Schober, Ralf; Kahn, Thomas; Moche, Michael


    To present an advanced approach for intraoperative image guidance in an open 0.5 T MRI and to evaluate its effectiveness for neurosurgical interventions by comparison with a dynamic scan-guided localization technique. The built-in scan guidance mode relied on successive interactive MRI scans. The additional advanced mode provided real-time navigation based on reformatted high-quality, intraoperatively acquired MR reference data, allowed multimodal image fusion, and used the successive scans of the built-in mode for quick verification of the position only. Analysis involved tumor resections and biopsies in either scan guidance (N = 36) or advanced mode (N = 59) by the same three neurosurgeons. Technical, surgical, and workflow aspects were compared. The image quality and hand-eye coordination of the advanced approach were improved. While the average extent of resection, neurologic outcome after functional MRI (fMRI) integration, and diagnostic yield appeared to be slightly better under advanced guidance, particularly for the main surgeon, statistical analysis revealed no significant differences. Resection times were comparable, while biopsies took around 30 minutes longer. The presented approach is safe and provides more detailed images and higher navigation speed at the expense of actuality. The surgical outcome achieved with advanced guidance is (at least) as good as that obtained with dynamic scan guidance. (c) 2006 Wiley-Liss, Inc.

  13. Recovery of brain abscess-induced stuttering after neurosurgical intervention. (United States)

    Sudo, Daisuke; Doutake, Youichi; Yokota, Hidenori; Watanabe, Eiju


    Stuttering occurs in approximately 5% of all children and 1% of adults. One type, neurogenic stuttering, is usually attributable to strokes or other structural damages to the brain areas that are responsible for language fluency. Here, we present the first case of neurogenic stuttering caused by a brain abscess. The patient was a 60-year-old man admitted for a seizure and administered an anticonvulsant, after which he began stuttering. MRI revealed a brain abscess in the left frontal lobe that extended to the dorsolateral prefrontal cortex (BA (Brodmann's area) 9 and 46), frontal eye field (BA 8) and premotor cortex and supplementary motor area (BA 6). After neurosurgical drainage and antibiotic treatment, the symptoms had resolved. This case is unique in that the therapeutic effects and localisation of the cause of stuttering were rapidly identified, allowing for a more accurate description of the neural circuitry related to stuttering. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  14. Surgical bedside master console for neurosurgical robotic system. (United States)

    Arata, Jumpei; Kenmotsu, Hajime; Takagi, Motoki; Hori, Tatsuya; Miyagi, Takahiro; Fujimoto, Hideo; Kajita, Yasukazu; Hayashi, Yuichiro; Chinzei, Kiyoyuki; Hashizume, Makoto


    We are currently developing a neurosurgical robotic system that facilitates access to residual tumors and improves brain tumor removal surgical outcomes. The system combines conventional and robotic surgery allowing for a quick conversion between the procedures. This concept requires a new master console that can be positioned at the surgical bedside and be sterilized. The master console was developed using new technologies, such as a parallel mechanism and pneumatic sensors. The parallel mechanism is a purely passive 5-DOF (degrees of freedom) joystick based on the author's haptic research. The parallel mechanism enables motion input of conventional brain tumor removal surgery with a compact, intuitive interface that can be used in a conventional surgical environment. In addition, the pneumatic sensors implemented on the mechanism provide an intuitive interface and electrically isolate the tool parts from the mechanism so they can be easily sterilized. The 5-DOF parallel mechanism is compact (17 cm width, 19cm depth, and 15cm height), provides a 505,050 mm and 90° workspace and is highly backdrivable (0.27N of resistance force representing the surgical motion). The evaluation tests revealed that the pneumatic sensors can properly measure the suction strength, grasping force, and hand contact. In addition, an installability test showed that the master console can be used in a conventional surgical environment. The proposed master console design was shown to be feasible for operative neurosurgery based on comprehensive testing. This master console is currently being tested for master-slave control with a surgical robotic system.

  15. Mixed reality ventriculostomy simulation: experience in neurosurgical residency. (United States)

    Hooten, Kristopher G; Lister, J Richard; Lombard, Gwen; Lizdas, David E; Lampotang, Samsun; Rajon, Didier A; Bova, Frank; Murad, Gregory J A


    Medicine and surgery are turning toward simulation to improve on limited patient interaction during residency training. Many simulators today use virtual reality with augmented haptic feedback with little to no physical elements. In a collaborative effort, the University of Florida Department of Neurosurgery and the Center for Safety, Simulation & Advanced Learning Technologies created a novel "mixed" physical and virtual simulator to mimic the ventriculostomy procedure. The simulator contains all the physical components encountered for the procedure with superimposed 3-D virtual elements for the neuroanatomical structures. To introduce the ventriculostomy simulator and its validation as a necessary training tool in neurosurgical residency. We tested the simulator in more than 260 residents. An algorithm combining time and accuracy was used to grade performance. Voluntary postperformance surveys were used to evaluate the experience. Results demonstrate that more experienced residents have statistically significant better scores and completed the procedure in less time than inexperienced residents. Survey results revealed that most residents agreed that practice on the simulator would help with future ventriculostomies. This mixed reality simulator provides a real-life experience, and will be an instrumental tool in training the next generation of neurosurgeons. We have now implemented a standard where incoming residents must prove efficiency and skill on the simulator before their first interaction with a patient.

  16. Noninvasive Hemodynamic Measurements During Neurosurgical Procedures in Sitting Position. (United States)

    Schramm, Patrick; Tzanova, Irene; Gööck, Tilman; Hagen, Frank; Schmidtmann, Irene; Engelhard, Kristin; Pestel, Gunther


    Neurosurgical procedures in sitting position need advanced cardiovascular monitoring. Transesophageal echocardiography (TEE) to measure cardiac output (CO)/cardiac index (CI) and stroke volume (SV), and invasive arterial blood pressure measurements for systolic (ABPsys), diastolic (ABPdiast) and mean arterial pressure (MAP) are established monitoring technologies for these kind of procedures. A noninvasive device for continuous monitoring of blood pressure and CO based on a modified Penaz technique (volume-clamp method) was introduced recently. In the present study the noninvasive blood pressure measurements were compared with invasive arterial blood pressure monitoring, and the noninvasive CO monitoring to TEE measurements. Measurements of blood pressure and CO were performed in 35 patients before/after giving a fluid bolus and a change from supine to sitting position, start of surgery, and repositioning from sitting to supine at the end of surgery. Data pairs from the noninvasive device (Nexfin HD) versus arterial line measurements (ABPsys, ABPdiast, MAP) and versus TEE (CO, CI, SV) were compared using Bland-Altman analysis and percentage error. All parameters compared (CO, CI, SV, ABPsys, ABPdiast, MAP) showed a large bias and wide limits of agreement. Percentage error was above 30% for all parameters except ABPsys. The noninvasive device based on a modified Penaz technique cannot replace arterial blood pressure monitoring or TEE in anesthetized patients undergoing neurosurgery in sitting position.

  17. [Brain injury knowledge in family members of neurosurgical patients]. (United States)

    Navarro-Main, Blanca; Castaño-León, Ana M; Munarriz, Pablo M; Gómez, Pedro A; Rios-Lago, Marcos; Lagares, Alfonso

    Several studies have shown misconceptions about brain injury in different populations. The aim of this study was to assess the knowledge and perceptions about brain injury of family members of neurosurgical patients in our hospital. The participants (n=81) were relatives of patients admitted to the neurosurgery department between February and August 2016. They voluntarily completed a 19-item true-false format survey about brain injury based on a translation of other questionnaires used in previous studies from other countries (USA, Canada, UK, Ireland and New Zealand). Also, some sociodemographic data were collected (age, sex, education level and the patient's pathology). Data analysis was developed through graphical modelling with a regularisation parameter plotted on a network representing the association of the items of the questionnaire from the response pattern of participants. Data analysis showed two conceptual areas with a high rate of wrong answers: behaviour and management of patients, and expectations about acquired brain injury recovery. The results obtained in this study would enable us to objectify misconceptions about acquired brain injury in patients' relatives attended in the neurosurgery department. This lack of knowledge could be a great obstacle in patients' recovery process. Therefore, we suggest placing the emphasis on the provision of information on brain injury to patients' families, especially with regard to its symptoms and course of development. Copyright © 2017 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Neurosurgical simulation and navigation with three-dimensional computer graphics. (United States)

    Hayashi, N; Endo, S; Shibata, T; Ikeda, H; Takaku, A


    We developed a pre-operative simulation and intra-operative navigation system with three-dimensional computer graphics (3D-CG). Because the 3D-CG created by the present system enables visualization of lesions via semitransparent imaging of the scalp surface and brain, the expected operative field could be visualized on the computer display pre-operatively. We used two different configurative navigators. One is assembled by an arciform arm and a laser pointer. The arciform arm consists of 3 joints mounted with rotary encoders forming an iso-center system. The distal end of the arm has a laser pointer, which has a CCD for measurement of the distance between the outlet of the laser beam, and the position illuminated by the laser pointer. Using this navigator, surgeons could accurately estimate the trajectory to the target lesion, and the boundaries of the lesion. Because the other navigator has six degrees of freedom and an interchangeable probe shaped like a bayonet on its tip, it can be used in deep structures through narrow openings. Our system proved efficient and yielded an unobstructed view of deep structures during microscopic neurosurgical procedures.

  19. WE-G-BRD-04: BEST IN PHYSICS (JOINT IMAGING-THERAPY): An Integrated Model-Based Intrafractional Organ Motion Tracking Approach with Dynamic MRI in Head and Neck Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H; Dolly, S; Anastasio, M; Li, H; Wooten, H; Gay, H; Mutic, S; Thorstad, W; Li, H [Washington University School of Medicine, Saint Louis, MO (United States); Victoria, J; Dempsey, J [ViewRay incorporated, Oakwood Village, Ohio (United States); Ruan, S [University of Rouen, QuantIF - EA 4108 LITIS, Rouen (France); Low, D [Deparment of Radiation Oncology, University of California Los Angeles, Los Angeles, CA (United States)


    Purpose: In-treatment dynamic cine images, provided by the first commercially available MRI-guided radiotherapy system, allow physicians to observe intrafractional motion of head and neck (H&N) internal structures. Nevertheless, high anatomical complexity and relatively poor cine image contrast/resolution have complicated automatic intrafractional motion evaluation. We proposed an integrated model-based approach to automatically delineate and analyze moving structures from on-board cine images. Methods: The H&N upper airway, a complex and highly deformable region wherein severe internal motion often occurs, was selected as the target-to-be-tracked. To reliably capture its motion, a hierarchical structure model containing three statistical shapes (face, face-jaw, and face-jaw-palate) was first built from a set of manually delineated shapes using principal component analysis. An integrated model-fitting algorithm was then employed to align the statistical shapes to the first to-be-detected cine frame, and multi-feature level-set contour propagation was performed to identify the airway shape change in the remaining frames. Ninety sagittal cine MR image sets, acquired from three H&N cancer patients, were utilized to demonstrate this approach. Results: The tracking accuracy was validated by comparing the results to the average of two manual delineations in 20 randomly selected images from each patient. The resulting dice similarity coefficient (93.28+/−1.46 %) and margin error (0.49+/−0.12 mm) showed good agreement with the manual results. Intrafractional displacements of anterior, posterior, inferior, and superior airway boundaries were observed, with values of 2.62+/−2.92, 1.78+/−1.43, 3.51+/−3.99, and 0.68+/−0.89 mm, respectively. The H&N airway motion was found to vary across directions, fractions, and patients, and highly correlated with patients’ respiratory frequency. Conclusion: We proposed the integrated computational approach, which for the first

  20. WE-G-BRD-04: BEST IN PHYSICS (JOINT IMAGING-THERAPY): An Integrated Model-Based Intrafractional Organ Motion Tracking Approach with Dynamic MRI in Head and Neck Radiotherapy

    International Nuclear Information System (INIS)

    Chen, H; Dolly, S; Anastasio, M; Li, H; Wooten, H; Gay, H; Mutic, S; Thorstad, W; Li, H; Victoria, J; Dempsey, J; Ruan, S; Low, D


    Purpose: In-treatment dynamic cine images, provided by the first commercially available MRI-guided radiotherapy system, allow physicians to observe intrafractional motion of head and neck (H&N) internal structures. Nevertheless, high anatomical complexity and relatively poor cine image contrast/resolution have complicated automatic intrafractional motion evaluation. We proposed an integrated model-based approach to automatically delineate and analyze moving structures from on-board cine images. Methods: The H&N upper airway, a complex and highly deformable region wherein severe internal motion often occurs, was selected as the target-to-be-tracked. To reliably capture its motion, a hierarchical structure model containing three statistical shapes (face, face-jaw, and face-jaw-palate) was first built from a set of manually delineated shapes using principal component analysis. An integrated model-fitting algorithm was then employed to align the statistical shapes to the first to-be-detected cine frame, and multi-feature level-set contour propagation was performed to identify the airway shape change in the remaining frames. Ninety sagittal cine MR image sets, acquired from three H&N cancer patients, were utilized to demonstrate this approach. Results: The tracking accuracy was validated by comparing the results to the average of two manual delineations in 20 randomly selected images from each patient. The resulting dice similarity coefficient (93.28+/−1.46 %) and margin error (0.49+/−0.12 mm) showed good agreement with the manual results. Intrafractional displacements of anterior, posterior, inferior, and superior airway boundaries were observed, with values of 2.62+/−2.92, 1.78+/−1.43, 3.51+/−3.99, and 0.68+/−0.89 mm, respectively. The H&N airway motion was found to vary across directions, fractions, and patients, and highly correlated with patients’ respiratory frequency. Conclusion: We proposed the integrated computational approach, which for the first

  1. The economic consequences of neurosurgical disease in low- and middle-income countries. (United States)

    Rudolfson, Niclas; Dewan, Michael C; Park, Kee B; Shrime, Mark G; Meara, John G; Alkire, Blake C


    OBJECTIVE The objective of this study was to estimate the economic consequences of neurosurgical disease in low- and middle-income countries (LMICs). METHODS The authors estimated gross domestic product (GDP) losses and the broader welfare losses attributable to 5 neurosurgical disease categories in LMICs using two distinct economic models. The value of lost output (VLO) model projects annual GDP losses due to neurosurgical disease during 2015-2030, and is based on the WHO's "Projecting the Economic Cost of Ill-health" tool. The value of lost economic welfare (VLW) model estimates total welfare losses, which is based on the value of a statistical life and includes nonmarket losses such as the inherent value placed on good health, resulting from neurosurgical disease in 2015 alone. RESULTS The VLO model estimates the selected neurosurgical diseases will result in $4.4 trillion (2013 US dollars, purchasing power parity) in GDP losses during 2015-2030 in the 90 included LMICs. Economic losses are projected to disproportionately affect low- and lower-middle-income countries, risking up to a 0.6% and 0.54% loss of GDP, respectively, in 2030. The VLW model evaluated 127 LMICs, and estimates that these countries experienced $3 trillion (2013 US dollars, purchasing power parity) in economic welfare losses in 2015. Regardless of the model used, the majority of the losses can be attributed to stroke and traumatic brain injury. CONCLUSIONS The economic impact of neurosurgical diseases in LMICs is significant. The magnitude of economic losses due to neurosurgical diseases in LMICs provides further motivation beyond already compelling humanitarian reasons for action.

  2. Pediatric Neurosurgical Outcomes Following a Neurosurgery Health System Intervention at Mulago National Referral Hospital in Uganda. (United States)

    Fuller, Anthony T; Haglund, Michael M; Lim, Stephanie; Mukasa, John; Muhumuza, Michael; Kiryabwire, Joel; Ssenyonjo, Hussein; Smith, Emily R


    Pediatric neurosurgical cases have been identified as an important target for impacting health disparities in Uganda, with over 50% of the population being less than 15 years of age. The objective of the present study was to evaluate the effects of the Duke-Mulago collaboration on pediatric neurosurgical outcomes in Mulago National Referral Hospital. We performed retrospective analysis of all pediatric neurosurgical cases who presented at Mulago National Referral Hospital in Kampala, Uganda, to examine overall, preprogram (2005-2007), and postprogram (2008-2013) outcomes. We analyzed mortality, presurgical infections, postsurgical infections, length of stay, types of procedures, and significant predictors of mortality. Data on neurosurgical cases was collected from surgical logbooks, patient charts, and Mulago National Referral Hospital's yearly death registry. Of 820 pediatric neurosurgical cases, outcome data were complete for 374 children. Among children who died within 30 days of a surgical procedure, the largest group was less than a year old (45%). Postinitiation of the Duke-Mulago collaboration, we identified an overall increase in procedures, with the greatest increase in cases with complex diagnoses. Although children ages 6-18 years of age were 6.66 times more likely to die than their younger counterparts preprogram, age was no longer a predictive variable postprogram. When comparing pre- and postprogram outcomes, mortality among pediatric patients within 30 days after a neurosurgical procedure increased from 4.3% to 10.0%, mortality after 30 days increased slightly from 4.9% to 5.0%, presurgical infections decreased by 4.6%, and postsurgery infections decreased slightly by 0.7%. Our data show the provision of more complex neurological procedures does not necessitate improved outcomes. Rather, combining these higher-level procedures with essential pre- and postoperative care and continued efforts in health system strengthening for pediatric neurosurgical

  3. Principles of models based engineering

    Energy Technology Data Exchange (ETDEWEB)

    Dolin, R.M.; Hefele, J.


    This report describes a Models Based Engineering (MBE) philosophy and implementation strategy that has been developed at Los Alamos National Laboratory`s Center for Advanced Engineering Technology. A major theme in this discussion is that models based engineering is an information management technology enabling the development of information driven engineering. Unlike other information management technologies, models based engineering encompasses the breadth of engineering information, from design intent through product definition to consumer application.

  4. Endoscopic and keyhole endoscope-assisted neurosurgical approaches: a qualitative survey on technical challenges and technological solutions. (United States)

    Marcus, Hani J; Cundy, Thomas P; Hughes-Hallett, Archie; Yang, Guang-Zhong; Darzi, Ara; Nandi, Dipankar


    The literature reflects a resurgence of interest in endoscopic and keyhole endoscope-assisted neurosurgical approaches as alternatives to conventional microsurgical approaches in carefully selected cases. The aim of this study was to assess the technical challenges of neuroendoscopy, and the scope for technological innovations to overcome these barriers. All full members of the Society of British Neurosurgeons (SBNS) were electronically invited to participate in an online survey. The open-ended structured survey asked three questions; firstly, whether the surgeon presently utilises or has experience with endoscopic or endoscope-assisted approaches; secondly, what they consider to be the major technical barriers to adopting such approaches; and thirdly, what technological advances they foresee improving safety and efficacy in the field. Responses were subjected to a qualitative research method of multi-rater emergent theme analysis. Three clear themes emerged: 1) surgical approach and better integration with image-guidance systems (20%), 2) intra-operative visualisation and improvements in neuroendoscopy (49%), and 3) surgical manipulation and improvements in instruments (74%). The analysis of responses to our open-ended survey revealed that although opinion was varied three major themes could be identified. Emerging technological advances such as augmented reality, high-definition stereo-endoscopy, and robotic joint-wristed instruments may help overcome the technical difficulties associated with neuroendoscopic approaches. Results of this qualitative survey provide consensus amongst the technology end-user community such that unambiguous goals and priorities may be defined. Systems integrating these advances could improve the safety and efficacy of endoscopic and endoscope-assisted neurosurgical approaches.

  5. Virtual Cerebral Aneurysm Clipping with Real-Time Haptic Force Feedback in Neurosurgical Education. (United States)

    Gmeiner, Matthias; Dirnberger, Johannes; Fenz, Wolfgang; Gollwitzer, Maria; Wurm, Gabriele; Trenkler, Johannes; Gruber, Andreas


    Realistic, safe, and efficient modalities for simulation-based training are highly warranted to enhance the quality of surgical education, and they should be incorporated in resident training. The aim of this study was to develop a patient-specific virtual cerebral aneurysm-clipping simulator with haptic force feedback and real-time deformation of the aneurysm and vessels. A prototype simulator was developed from 2012 to 2016. Evaluation of virtual clipping by blood flow simulation was integrated in this software, and the prototype was evaluated by 18 neurosurgeons. In 4 patients with different medial cerebral artery aneurysms, virtual clipping was performed after real-life surgery, and surgical results were compared regarding clip application, surgical trajectory, and blood flow. After head positioning and craniotomy, bimanual virtual aneurysm clipping with an original forceps was performed. Blood flow simulation demonstrated residual aneurysm filling or branch stenosis. The simulator improved anatomic understanding for 89% of neurosurgeons. Simulation of head positioning and craniotomy was considered realistic by 89% and 94% of users, respectively. Most participants agreed that this simulator should be integrated into neurosurgical education (94%). Our illustrative cases demonstrated that virtual aneurysm surgery was possible using the same trajectory as in real-life cases. Both virtual clipping and blood flow simulation were realistic in broad-based but not calcified aneurysms. Virtual clipping of a calcified aneurysm could be performed using the same surgical trajectory, but not the same clip type. We have successfully developed a virtual aneurysm-clipping simulator. Next, we will prospectively evaluate this device for surgical procedure planning and education. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Association of Hospitalization for Neurosurgical Operations in Magnet Hospitals With Mortality and Length of Stay. (United States)

    Missios, Symeon; Bekelis, Kimon


    The association of Magnet hospital status with improved surgical outcomes remains an issue of debate. To investigate whether hospitalization in a Magnet hospital is associated with improved outcomes for patients undergoing neurosurgical operations. A cohort study was executed using all patients undergoing neurosurgical operations in New York registered in the Statewide Planning and Research Cooperative System database from 2009 to 2013. We examined the association of Magnet status hospitalization after neurosurgical operations with inpatient case fatality and length of stay (LOS). We employed an instrumental variable analysis to simulate a randomized trial. Overall, 190 787 patients underwent neurosurgical operations. Of these, 68 046 (35.7%) were hospitalized in Magnet hospitals, and 122 741 (64.3%) in non-Magnet institutions. Instrumental variable analysis demonstrated that hospitalization in Magnet hospitals was associated with decreased case fatality (adjusted difference, -0.8%; -95% confidence interval, -0.7% to -0.6%), and LOS (adjusted difference, -1.9; 95% confidence interval, -2.2 to -1.5) in comparison to non-Magnet hospitals. These associations were also observed in propensity score adjusted mixed effects models. These associations persisted in prespecified subgroups of patients undergoing spine surgery, craniotomy for tumor resection, or neurovascular interventions. We identified an association of Magnet hospitals with lower case fatality, and shorter LOS in a comprehensive New York State patient cohort undergoing neurosurgical procedures. Copyright © 2017 by the Congress of Neurological Surgeons

  7. Mentoring models in neurosurgical training: Review of literature. (United States)

    Akhigbe, Taiwo; Zolnourian, Ardalan; Bulters, Diederik


    Effective mentoring is an invaluable element in the development of next generation of neurosurgeons. A mentor helps to develop professional core values, technical and non-technical skills, attitudes and disposition required to be qualified and competent neurosurgeon. Giving the invaluable significance of mentoring in neurosurgery, we undertook this literature review to identify mentoring models evaluating its success and relative benefit. Literature search identified using MeSH word 'mentor', mentoring, mentorship, mentoring model, neurosurgery' in MEDLINE, EMBASE and Scopus databases from 1990 to 2016. Literature reviewed to identify status of mentoring in neurosurgery, potential barriers, pitfalls and future framework for mentoring in neurosurgery. Additional articles identified through manual search of reference lists. A total of 247 studies were obtained from electronic databases, after removing duplicates, abstracts, letters to the editor and non-neurosurgery papers. Sixteen full text articles retrieved out of which five met the inclusion criteria. Generally, there is paucity of articles regarding mentoring in neurosurgery, all included papers were written in English Language, all of them described mentoring model used including simulation, distance, collaborative, facilitative tele-mentoring and peer mentoring. Mentoring in Neurosurgery is an important aspect of personal and professional development of neurosurgical trainees, currently there is decline in traditional apprenticeship due to increase demand for modern use of specialised technology, simulation and tele-medicine in neurosurgery practice. Effective and efficient mentoring will be an interplay of six mentoring models (collaborative, facilitative, distance, simulation, tele mentoring and peer mentoring) identified. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  8. Simulation-based interpersonal communication skills training for neurosurgical residents. (United States)

    Harnof, Sagi; Hadani, Moshe; Ziv, Amitai; Berkenstadt, Haim


    Communication skills are an important component of the neurosurgery residency training program. We developed a simulation-based training module for neurosurgery residents in which medical, communication and ethical dilemmas are presented by role-playing actors. To assess the first national simulation-based communication skills training for neurosurgical residents. Eight scenarios covering different aspects of neurosurgery were developed by our team: (1) obtaining informed consent for an elective surgery, (2) discharge of a patient following elective surgery, (3) dealing with an unsatisfied patient, (4) delivering news of intraoperative complications, (5) delivering news of a brain tumor to parents of a 5 year old boy, (6) delivering news of brain death to a family member, (7) obtaining informed consent for urgent surgery from the grandfather of a 7 year old boy with an epidural hematoma, and (8) dealing with a case of child abuse. Fifteen neurosurgery residents from all major medical centers in Israel participated in the training. The session was recorded on video and was followed by videotaped debriefing by a senior neurosurgeon and communication expert and by feedback questionnaires. All trainees participated in two scenarios and observed another two. Participants largely agreed that the actors simulating patients represented real patients and family members and that the videotaped debriefing contributed to the teaching of professional skills. Simulation-based communication skill training is effective, and together with thorough debriefing is an excellent learning and practical method for imparting communication skills to neurosurgery residents. Such simulation-based training will ultimately be part of the national residency program.

  9. [High risk factors of upper gastrointestinal bleeding after neurosurgical procedures]. (United States)

    Zheng, Kang; Wu, Gang; Cheng, Neng-neng; Yao, Cheng-jun; Zhou, Liang-fu


    To analyze high risk factors of postoperative upper gastrointestinal (GI) bleeding after neurosurgery so as to give guidance for prevention of GI bleeding. A questionnaire was developed to investigate the medical records of 1500 patients who were hospitalized and underwent neurosurgical operations in 1997. Logistic regression analysis was made. 1430 valid questionnaires were obtained. Postoperative upper GI bleeding occurred in 75 patients (5.24%). The incidence of upper GI bleeding were 6.64% (54/813) in the male patients and 3.40% (21/617) in the female persons (P = 0.007); 9.88% (41/415) in those aged > 50 and 3.35% in those aged hematoma, intraventricular hemorrhage, subdural hematoma, and extradural hematoma were 15.7%, 10.0%, 6.00%, and 2.94% respectively (P = 0.02). The incidence of upper GI bleeding of the patients with tumors of fourth ventricle of cerebrum, brainstem, cerebral hemisphere, and sellar hypothalamus were 15.79% (3/19), 7.89%, 5.71%, and 3.74% respectively. In the emergent cases, the incidence of upper GI bleeding was higher in those with hypertension. The incidence of upper GI bleeding was 5.46% in the patients undergoing adrenocortical hormone treatment, significantly higher than that in those who did not receive such treatment (2.13%). Patients who are at high risk of developing postoperative upper GI bleeding including that: age greater than 50 years; male; Glasgow Coma Score less than 10 pre and post operation; The lesion was located in brain stem and forth ventricle; Hypertensive cerebral hemorrhage; Intracerebral and intraventricular hemorrhagic brain trauma; Postoperative pneumonia, brain edema, encephalic high pressure, pyogenic infection of the central nervous system and other postoperative complications. The mortality of patients with postoperative upper GI bleeding was evidently higher than that of the patients without postoperative upper GI bleeding.

  10. Trends of the neurosurgical economy in the United States. (United States)

    Johnson, William C; Seifi, Ali


    The objective of this study was to identify the neurosurgical MS-DRGs highest national bills and to analyze economic, demographic, and patient outcome trends. This retrospective cohort study used the Nationwide Inpatient Sample (NIS) database to achieve the results. All MS-DRG codes for the years 2014 were ranked based on total aggregate charges. The highest ranked relevant to neurosurgery were identified and retrospectively reviewed to 2008. The data was analyzed by Z-test. In 2014, NIS reported the MS-DRG with the highest national bill of $22,894,340,928 was "Spinal Fusion Except Cervical without MCC," which also had the largest rise over the cohort period, increasing from $15,853,679,222 in 2008 (p < .001). It was also the MS-DRG with the highest incidence, totaling 1,443,112 discharges and increasing from 190,692 in 2008 to 214,100 in 2014 (p < .10). "Craniotomy with major Device Implant/Acute Complex CNS Procedure w/MCC or Chemo Implant" had the longest length of stay (LOS) with a mean patient stay of 12.9 days. This MS-DRG also had the oldest patient population mean age of 57.5 years old. "Craniotomy & Endovascular Intracranial Procedures with MCC" had the most in-hospital deaths totaling 28,707 increasing significantly from 3602 in 2008 to 4410 in 2014 (p < .05). "Spinal fusion except cervical without MCC," had the highest national bill in the USA over the period of the cohort. Healthcare organizations can benefit from awareness of this information by using it to establish the most efficient healthcare investments and preparing a health-care roadmap for the following decades. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Neurosurgical simulation by interactive computer graphics on iPad. (United States)

    Maruyama, Keisuke; Kin, Taichi; Saito, Toki; Suematsu, Shinya; Gomyo, Miho; Noguchi, Akio; Nagane, Motoo; Shiokawa, Yoshiaki


    Presurgical simulation before complicated neurosurgery is a state-of-the-art technique, and its usefulness has recently become well known. However, simulation requires complex image processing, which hinders its widespread application. We explored handling the results of interactive computer graphics on the iPad tablet, which can easily be controlled anywhere. Data from preneurosurgical simulations from 12 patients (4 men, 8 women) who underwent complex brain surgery were loaded onto an iPad. First, DICOM data were loaded using Amira visualization software to create interactive computer graphics, and ParaView, another free visualization software package, was used to convert the results of the simulation to be loaded using the free iPad software KiwiViewer. The interactive computer graphics created prior to neurosurgery were successfully displayed and smoothly controlled on the iPad in all patients. The number of elements ranged from 3 to 13 (mean 7). The mean original data size was 233 MB, which was reduced to 10.4 MB (4.4% of original size) after image processing by ParaView. This was increased to 46.6 MB (19.9%) after decompression in KiwiViewer. Controlling the magnification, transfer, rotation, and selection of translucence in 10 levels of each element were smoothly and easily performed using one or two fingers. The requisite skill to smoothly control the iPad software was acquired within 1.8 trials on average in 12 medical students and 6 neurosurgical residents. Using an iPad to handle the result of preneurosurgical simulation was extremely useful because it could easily be handled anywhere.

  12. An analysis of the citation climate in neurosurgical literature and description of an interfield citation metric. (United States)

    Madhugiri, Venkatesh S; Sasidharan, Gopalakrishnan M; Subeikshanan, Venkatesan; Dutt, Akshat; Ambekar, Sudheer; Strom, Shane F


    The citation climate in neurosurgical literature is largely undefined. To study the patterns of citation of articles in neurosurgery as a scientific field and to evaluate the performance of neurosurgery journals vis-à-vis journals in other fields. References cited in articles published in neurosurgery journals during a specified time period were analyzed to determine the age of articles cited in neurosurgical literature. In the next analysis, articles published in neurosurgical journals were followed up for 13 years after publication. The postpublication citation patterns were analyzed to determine the time taken to reach the maximally cited state and the time when articles stopped being cited. The final part of the study dealt with the evolution of a new interfield citation metric, which was then compared with other standardized citation indexes. The mean ± SD age of articles cited in neurosurgical literature was 11.6 ± 11.7 years (median, 8 years). Citations received by articles gradually increased to a peak (at 6.25 years after publication in neurosurgery) and then reached a steady state; articles were still cited well into the late postpublication period. Neurosurgical articles published in nonneurosurgical high-impact journals were cited more highly than those in neurosurgical journals, although they took approximately the same time to reach the maximally cited state (7.2 years). The most cited pure neurosurgery journal was Neurosurgery. The citation climate for neurosurgery was adequately described. The interfield citation metric was able to ensure cross-field comparability of journal performance. G1, group 1G2, group 2G3, group 3G4, group 4IFCM, interfield citation metric.

  13. Infection Rate after Cranial Neurosurgical Procedures: A Prospective Single-Center Study. (United States)

    Strahm, Carol; Albrich, Werner C; Zdravkovic, Vilijam; Schöbi, Barbara; Hildebrandt, Gerhard; Schlegel, Matthias


    To determine infection rate (IR) and to identify modifiable risk factors (RF) in cranial neurosurgery in a neurosurgical department for tertiary referral as part of an infection control surveillance to reduce surgical site infections (SSI). A prospective SSI incidence cohort study from February 2013 to January 2014 was performed in a tertiary-care neurosurgical teaching hospital and referral center. All consecutive adults undergoing any cranial neurosurgical procedure were included. Data were collected by a trained member of the infection control staff during the twice-weekly visits of the hospitalized patients. Follow-up was 30 days (procedures without implant) and 1 year (procedures involving permanent implants). SSI was diagnosed according to criteria of CDC. A total of 317 patients undergoing 333 index procedures were included. The median age was 61 years (range, 17-91 years) and 46% were female. Survival in patients with completed follow-up was 76% (196/258). Overall, IR was 7.2% (24/333 index procedures); in 96% (23/24), a neurosurgical implant was involved. The IR of extraventricular drainage (EVD) was 12.5% (13.1/1000 EVD days). The main causative pathogens were Staphylococcus aureus followed by coagulase-negative staphylococci and Propionibacterium acnes. Independent RF for neurosurgical SSI were EVD as part of the index operation and body mass index >25 kg/m 2 . IR was in accordance with recent prospective single-center studies (reported IR between 1.6% and 9%). EVD placement was identified as the strongest modifiable RF for SSI in cranial neurosurgical procedures. The need for standard infection control procedures for the insertion and maintenance of EVDs to avoid their contamination is reinforced. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Evaluation of a mobile augmented reality application for image guidance of neurosurgical interventions. (United States)

    Kramers, Matthew; Armstrong, Ryan; Bakhshmand, Saeed M; Fenster, Aaron; de Ribaupierre, Sandrine; Eagleson, Roy


    Image guidance can provide surgeons with valuable contextual information during a medical intervention. Often, image guidance systems require considerable infrastructure, setup-time, and operator experience to be utilized. Certain procedures performed at bedside are susceptible to navigational errors that can lead to complications. We present an application for mobile devices that can provide image guidance using augmented reality to assist in performing neurosurgical tasks. A methodology is outlined that evaluates this mode of visualization from the standpoint of perceptual localization, depth estimation, and pointing performance, in scenarios derived from a neurosurgical targeting task. By measuring user variability and speed we can report objective metrics of performance for our augmented reality guidance system.

  15. Medical negligence. An overview of legal theory and neurosurgical practice: causation. (United States)

    Todd, Nicholas V


    This article discusses the principles of the law in relation to legal causation as applied to neurosurgical practice. Causation is a causal link between a breach of duty of care and the final harm. The fundamental "but-for" test for causation will be discussed, together with Chester v Afshar modified causation, prospective and retrospective probabilities of harm, loss of a chance, causation following breach of duty of care by omission, breaking the chain of causation, material contribution and the law in relation to multiple defendants, with neurosurgical examples.

  16. Neurosurgical management of anterior meningo-encephaloceles about 60 cases (United States)

    Rifi, Loubna; Barkat, Amina; El Khamlichi, Abdeslam; Boulaadas, Malek; El Ouahabi, Abdessamad


    Anterior meningo-encephaloceles (AME) are congenital malformations characterized by herniation of brain tissue and meninges through a defect in the cranium, in frontal, orbital, nasal and ethmoidal regions. The management of this complex congenital malformation is controversial according to whether use, an intracranial, extra-cranial or combined approach. This is the first largest series published in Africa, in which we present our experience in the operative management of AME; we share our recommendation in technical consideration for surgical approach with review of the literature. All patients beneficed of neuro-radiological investigations including Plan X rays, Spiral Three dimensional CT scan and MRI. Ophthalmologic and maxillo-facial evaluations were done in all the cases. MEA are surgically approached in various ways, mainly on the basis of its location and type, by cranio-facial approach in one-step, or in two stages by intracranial approach followed by facial approach, only by cranial approach or facial approach. The surgical results were evaluated in the follow up on the basis of disappearance of cranio-facial tumefaction with correction of hypertelorism. 60 children with AME were treated in our department between January 1992 and December 2012. The mean age at time of surgery was 14 months (20 days to 18 years) with slight men predominance (28 females/32 males). Cranio-facial team operated 21 patients, 16 were operated in two stages by intracranial approach followed by facial approach, 20 cases beneficed the neurosurgical approach and three only the facial approach Some post operative complications were observed: 2 cases of post operative hydrocephalus underwent shunt; CSF fistulas in three cases cured by spinal drainage, one death due to per operative hypothermia, 3 cases of recurrence how needed second surgery. After mean follow up for 80 months (1 year to 19 years) theses techniques permitted a good cosmetics results in 42 cases, average cosmetics

  17. Regional cerebral blood flow and P300 in neurosurgical disorders

    International Nuclear Information System (INIS)

    Funahashi, Kazuyoshi; Hyoutani, Genhachi; Maeshima, Shinichirou; Miyamoto, Kazuki; Kuwata, Toshikazu; Terada, Tomoaki; Komai, Norihiko


    Changes in regional cerebral blood flow (rCBF), P300 and higher brain function were studied in neurosurgical patients with localized lesions on computed tomography (CT). Twenty-five patients ranging in age from 30 to 81 were studied. Nineteen of these suffered from cerebrovascular disease and six had tumors. Using the oddball paradigm, P300 components were elicited by rate tones (2 KHz) and recorded at Cz and Pz referred to linked ear-lobe electorodes. The P300 latencies of the patients were statistically compared with those of 27 normal subjects. Higher brain function was evaluated with the following psychological tests: a rating scale for psychological function (Sano and Tanemura), Mini-Mental State (MMS), Hasegawa's Dementia Scale (HDS) and the 'Kanahiroi' test. Regional CBF was measured in the bilateral cerebral cortices (the frontal, temporal and occipital lobes), thalamus and basal ganglia by means of a cold xenon CT method. The laterality indices of rCBF (Rt. rCBF/Lt. rCBF) in the bilateral symmetrical areas of the patients were compared to those of 8 normal subjects. Of the 25 patients, 12 revealed prolongation of P300 latency. Ten (86%) of the 12 with prolonged P300 latency showed reduction of rCBF in the right cerebral hemisphere (rt. frontal lobe, rt. thalamus and rt. basal ganglia). Significant correlations (P<0.025) were recognized between the P300 latencies and the laterality indices of rCBF in the frontal lobe and thalamus. There was a significant correlation (P<0.05) between the scores of MMS and HDS and the laterality indicies of rCBF in the frontal lobe only. In the 13 patients with normal P300 latency, 6 (46%) displayed no reduction in rCBF. The remaining 7 patients with normal P300 showed reduction of rCBF in the left hemisphere. Both right frontal lobe and right thalamus have an important role affecting the prolongation of P300 latency and disturbance of cognitive functions. (author)

  18. Point-of-View Recording Devices for Intraoperative Neurosurgical Video Capture

    Directory of Open Access Journals (Sweden)

    Jose Luis Porras


    Full Text Available AbstractIntroduction: The ability to record and stream neurosurgery is an unprecedented opportunity to further research, medical education, and quality improvement. Here, we appraise the ease of implementation of existing POV devices when capturing and sharing procedures from the neurosurgical operating room, and detail their potential utility in this context.Methods: Our neurosurgical team tested and critically evaluated features of the Google Glass and Panasonic HX-A500 cameras including ergonomics, media quality, and media sharing in both the operating theater and the angiography suite.Results: Existing devices boast several features that facilitate live recording and streaming of neurosurgical procedures. Given that their primary application is not intended for the surgical environment, we identified a number of concrete, yet improvable, limitations.Conclusion: The present study suggests that neurosurgical video capture and live streaming represents an opportunity to contribute to research, education, and quality improvement. Despite this promise, shortcomings render existing devices impractical for serious consideration. We describe the features that future recording platforms should possess to improve upon existing technology.

  19. Massive pediatric neurosurgical injuries and lessons learned following a tornado disaster in Alabama. (United States)

    Chern, Joshua J; Miller, Joseph H; Tubbs, R Shane; Whisenhunt, Thomas R; Johnston, James M; Wellons, John C; Rozzelle, Curtis J; Blount, Jeffrey P; Oakes, W Jerry


    A large volume of patients presented to a Level I pediatric trauma center during and after a recent tornado disaster. Injuries of the central and peripheral nervous systems and the medical responses of a pediatric neurosurgical team are reviewed. The clinical courses of patients who suffered cranial, spinal, and peripheral nerve injuries due to the tornado storm are reported. The clinical actions taken by the neurosurgical team during and after the event are reviewed and the lessons learned are discussed. The tornado storm system moved through the Tuscaloosa and Birmingham metropolitan areas on the early evening hours of April 27, 2011. Twenty-four patients received care from the neurosurgical team. A total of 11 cranial (including placement of an external ventricular drain), 2 spine, and 2 peripheral procedures were performed for the victims. Nine procedures were performed within the first 12 hours of the event, and an additional 6 surgeries were performed in the following 24 hours. Injuries of the peripheral nervous system often presented in a delayed fashion. Several key components were identified that enabled adequate neurosurgical care for a large influx of acute patients. Massive casualties due to tornados are rare. A well-organized physician team working with the hospital administration may decrease the mortality and morbidity of such events.

  20. The British Neurosurgical Trainee Research Collaborative: Five years on. (United States)

    Chari, Aswin; Jamjoom, Aimun A; Edlmann, Ellie; Ahmed, Aminul I; Coulter, Ian C; Ma, Ruichong; May, Paul; Brennan, Paul M; Hutchinson, Peter J A; Kolias, Angelos G


    Since its inception in 2012, the British Neurosurgical Trainee Research Collaborative (BNTRC) has established itself as a robust example of a trainee-led research collaborative. This article summarises the work of the collaborative over its first 5 years of existence, outlining the structure, its research projects, impact and future directions.

  1. Neurosurgical targets for compulsivity: what can we learn from acquired brain lesions?

    NARCIS (Netherlands)

    Figee, Martijn; Wielaard, Ilse; Mazaheri, Ali; Denys, Damiaan


    Treatment efficacy of deep brain stimulation (DBS) and other neurosurgical techniques in refractory obsessive-compulsive disorder (OCD) is greatly dependent on the targeting of relevant brain regions. Over the years, several case reports have been published on either the emergence or resolution of

  2. Infection Rate in 1033 Elective Neurosurgical Procedures at a University Hospital in South China. (United States)

    Zhu, Hongwei; Liu, Xiyao; Wang, Zhanxiang


    Objective  Infection following surgery is a serious complication, especially in neurosurgery. The aim of the study is to report the change of incidence rates of infection in patients undergoing elective neurosurgical procedures at a university hospital in South China as well as the risk factors. Material and Methods  The medical records and postoperative courses for patients undergoing 1,033 neurosurgical procedures from 2008 to 2014 were reviewed retrospectively to determine the incidence of neurosurgical infection, the identity of the offending organisms, and the factors associated with infection. Results  A total of 33 patients (40 cases) experienced postoperative infection representing 3.19% of the study population. Twenty cases were incision infections (1.94%), and 20 were cranial/spinal infections (1.94%) including 15 intracranial infections and 5 intraspinal infections. The 2.4-fold greater incidence of postoperative infection in 2008 to 2010 was compared with that in 2011 to 2014 with perioperative antibiotic prophylaxis ( p neurosurgery (1.08%). The most common offending organism was Staphylococcus aureus (27.5%). Foreign body implantation, operative time > 4 hours, and cerebrospinal fluid (CSF) leak (13 infections in 158 patients; p <0.001) were risk factors for infections ( p <0.05). Conclusion  The neurosurgical infection rate is usually low with perioperative antibiotic prophylaxis even in developing countries. Less foreign body implantation, shorter operative times, and controlling CSF leak could reduce infection rates. Georg Thieme Verlag KG Stuttgart · New York.

  3. Long-term outcome of neurosurgical untethering on neurosegmental motor and ambulation levels

    NARCIS (Netherlands)

    Schoenmakers, M. A. G. C.; Gooskens, R. H. J. M.; Gulmans, V. A. M.; Hanlo, P. W.; Vandertop, W. P.; Uiterwaal, C. S. P. M.; Helders, P. J. M.


    The aim of this study was to determine the long-term outcome of neurosurgical untethering on neurosegmental motor level and ambulation level in children with tethered spinal cord syndrome. Forty-four children were operated on (17 males, 27 females; mean age at operation 6 years 2 months, SD 5

  4. Medical negligence. An overview of legal theory and neurosurgical practice: duty of care. (United States)

    Todd, Nicholas V


    A working knowledge of the legal principles of medical negligence is helpful to neurosurgeons. It helps them to act in a "reasonable, responsible and logical" manner, that is a practice that is consistent with the surgical practice of their peers. This article will review and explain the relevant medical law in relation to duty of care with illustrative neurosurgical cases.

  5. The Johns Hopkins Hunterian Laboratory Philosophy: Mentoring Students in a Scientific Neurosurgical Research Laboratory. (United States)

    Tyler, Betty M; Liu, Ann; Sankey, Eric W; Mangraviti, Antonella; Barone, Michael A; Brem, Henry


    After over 50 years of scientific contribution under the leadership of Harvey Cushing and later Walter Dandy, the Johns Hopkins Hunterian Laboratory entered a period of dormancy between the 1960s and early 1980s. In 1984, Henry Brem reinstituted the Hunterian Neurosurgical Laboratory, with a new focus on localized delivery of therapies for brain tumors, leading to several discoveries such as new antiangiogenic agents and Gliadel chemotherapy wafers for the treatment of malignant gliomas. Since that time, it has been the training ground for 310 trainees who have dedicated their time to scientific exploration in the lab, resulting in numerous discoveries in the area of neurosurgical research. The Hunterian Neurosurgical Laboratory has been a unique example of successful mentoring in a translational research environment. The laboratory's philosophy emphasizes mentorship, independence, self-directed learning, creativity, and people-centered collaboration, while maintaining productivity with a focus on improving clinical outcomes. This focus has been served by the diverse backgrounds of its trainees, both in regard to educational status as well as culturally. Through this philosophy and strong legacy of scientific contribution, the Hunterian Laboratory has maintained a positive and productive research environment that supports highly motivated students and trainees. In this article, the authors discuss the laboratory's training philosophy, linked to the principles of adult learning (andragogy), as well as the successes and the limitations of including a wide educational range of students in a neurosurgical translational laboratory and the phenomenon of combining clinical expertise with rigorous scientific training.

  6. Innovative solutions: sample financial management business plan: neurosurgical intensive care unit. (United States)

    Villanueva-Baldonado, Analiza; Barrett-Sheridan, Shirley E


    This article describes one institution's intention to implement a financial management business plan for a neurosurgical intensive care unit in a level I trauma center. The financial objective of this proposed business plan includes a service increase in the patient population requiring critical care in a way that will help control costs.

  7. Cognitive components underpinning the development of model-based learning. (United States)

    Potter, Tracey C S; Bryce, Nessa V; Hartley, Catherine A


    Reinforcement learning theory distinguishes "model-free" learning, which fosters reflexive repetition of previously rewarded actions, from "model-based" learning, which recruits a mental model of the environment to flexibly select goal-directed actions. Whereas model-free learning is evident across development, recruitment of model-based learning appears to increase with age. However, the cognitive processes underlying the development of model-based learning remain poorly characterized. Here, we examined whether age-related differences in cognitive processes underlying the construction and flexible recruitment of mental models predict developmental increases in model-based choice. In a cohort of participants aged 9-25, we examined whether the abilities to infer sequential regularities in the environment ("statistical learning"), maintain information in an active state ("working memory") and integrate distant concepts to solve problems ("fluid reasoning") predicted age-related improvements in model-based choice. We found that age-related improvements in statistical learning performance did not mediate the relationship between age and model-based choice. Ceiling performance on our working memory assay prevented examination of its contribution to model-based learning. However, age-related improvements in fluid reasoning statistically mediated the developmental increase in the recruitment of a model-based strategy. These findings suggest that gradual development of fluid reasoning may be a critical component process underlying the emergence of model-based learning. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. A prospective emergency department-based study of pattern and outcome of neurologic and neurosurgical diseases in Haiti. (United States)

    Barthélemy, Ernest Joseph; Benjamin, Ernest; Edouard Jean-Pierre, Marie Yolaine; Poitevien, Geneviève; Ernst, Silvia; Osborn, Irene; Germano, Isabelle M


    To perform the first prospective survey of neurologic and neurosurgical emergency department (ED) admissions in Haiti. Data of all ED admissions at 3 Haitian hospitals for 90 consecutive days per site were collected prospectively. Patients who were given a diagnosis of a neurologic or neurosurgical disorder by the ED physician were entered in a deidentified database including demographics, presenting symptoms, brain imaging (when available), requests for neurosurgical consultation, and outcome. Of the 7628 patients admitted to the ED during this study, 1243 patients had a neurologic disorder, yielding an ED-based neurologic disease prevalence of 16%. The 3 most common neurologic diseases were cerebrovascular disease (31%), neurotrauma (28%), and altered mental status (12%). Neurosurgical pathologies represented 19% of all neurologic admissions with a combined ED-based disease prevalence of 3%. Mortality rate was 9%. The most common neurosurgical disease was neurotrauma (87%), caused by motor vehicle accidents (59%), falls (20%), and assault (17%). Neurosurgical procedures were performed in 14 of 208 patients with a mortality rate of 33%. This prospective survey represents the first study of neurosurgical or neurologic disease patterns in Haiti. The results suggest specific disease priorities for this population that can guide efforts to improve Haitian health care and conduct more comprehensive epidemiologic studies in Haiti. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Social Media Metrics and Bibliometric Profiles of Neurosurgical Departments and Journals: Is There a Relationship? (United States)

    Alotaibi, Naif M; Guha, Daipayan; Fallah, Aria; Aldakkan, Abdulrahman; Nassiri, Farshad; Badhiwala, Jetan H; Ibrahim, George M; Shamji, Mohammed F; Macdonald, R Loch; Lozano, Andres M


    Social media plays an increasingly important role in dissemination of knowledge and raising awareness of selected topics among the general public and the academic community. To investigate the relationship between social media metrics and academic indices of neurosurgical programs and journals. A 2-step online search was performed to identify official social media accounts of neurosurgical departments that were accredited by the Accreditation Council for Graduate Medical Education and the Royal College of Physicians and Surgeons of Canada. Dedicated neurosurgery and spine journals' social media accounts also were identified through an online search on SCImago Journal and Country Rank portal. Nonparametric tests were performed with bootstrapping to compare groups and to look for correlations between social media and academic metrics. We identified 36 social media accounts officially affiliated with academic neurosurgical institutions. These accounts represented 22 of 119 neurosurgical programs in North America (18.4%). The presence of a social media account for neurosurgical departments was associated with statistically significant higher values of academic impact metrics (P social media metrics for neurosurgical department accounts, however, did not correlate with any values of academic indices. For journals, there were 11 journals present on social media and had greater academic metrics compared with journals without social media presence (P Social media presence is associated with stronger academic bibliometrics profiles for both neurosurgical departments and journals. The impact of social media metrics on indices of scientific impact in neurosurgery is not known. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Academic impact and rankings of American and Canadian neurosurgical departments as assessed using the h index. (United States)

    Ponce, Francisco A; Lozano, Andres M


    The authors undertook a study to estimate the relative academic impact of neurosurgical departments in Canada and the US using the h index, a measure of the number of citations received by a collection of work. The study included 99 departments of neurosurgery with residency programs participating in the US National Residency Matching Program, and the 14 analogous Canadian programs. Three types of h indices were determined-one reflecting the cumulative work attributed to a neurosurgical department, h(c); one restricted to the cumulative work published over the past 10 years, h(10); and one limited to work published in 2 major North American neurosurgical journals, h(NS)(10). For an article to be included, attribution to a neurosurgical department had to appear in the address field in the database Thomson's ISI Web of Science. The three h indices were compared with each other, and their relation to other measures such as size of the department, degrees held by the faculty, and research funding was examined. Significant correlations were found between the citation indices and faculty size, number of publications and the types of degrees held by the faculty, and funding by the US NIH. Three types of authorship were identified: neurosurgeon, nonclinician researcher, and nonneurosurgeon clinical affiliate. The degree to which the latter 2 nonneurosurgeon categories contributed to the departmental h index varied among departments and can confound interdepartmental comparison. Limiting articles to those published in neurosurgical journals appeared to correct for the influence of nonneurosurgeons in departmental impact and reflect neurosurgeon-driven scholarship. The h index may be useful in evaluating output across neurosurgery departments.

  11. Association of Prior Falls with Adverse Outcomes After Neurosurgical Operations in the Elderly. (United States)

    Bekelis, Kimon; Rahmani, Redi; Kim-Hyung, Joon; Calnan, Daniel; MacKenzie, Todd A


    Despite the increasing number of elderly patients undergoing neurosurgical interventions, there are limited resources for preoperative assessment of frailty in this population. We investigated the association between recent history of falls and surgical outcomes for these patients. We performed a prospective cohort study of all patients, 65 years and older, undergoing elective neurosurgical procedures from 2014-2015 in a tertiary referral medical center. We examined the association of sustaining a fall in the 6 months before the operation with discharge to a facility, readmissions, and complications in the first 30 days after discharge. In order to control for confounding, we used multivariable regression models and propensity score conditioning. Mixed-effects models were used to control for clustering at the surgeon level. During the study period, 143 elderly patients underwent a neurosurgical procedure and met the inclusion criteria. Of these, 53.1% had a history of falls preoperatively. Mixed-effects multivariable logistic regression analysis demonstrated an association between preoperative falls and discharge to a facility (odds ratio [OR], 1.35; 95% confidence interval [CI], 1.23-1.47), 30-day readmissions (OR, 1.57; 95% CI, 1.36-1.78), and 30-day complications (OR, 1.13; 95% CI, 1.03-1.23). Similar associations were present in propensity score-adjusted models and models stratified by cranial and spinal procedures. History of at least 1 fall in the 6 months before a neurosurgical operation was associated with increased risk of discharge to a facility, readmissions, and complications in the first 30 days after discharge. History of prior falls should be taken into account during the preoperative risk assessment of neurosurgical patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. The characteristics of post-neurosurgical bacterial meningitis in elective neurosurgery in 2012: A single institute study. (United States)

    Tian, Runfa; Hao, Shuyu; Hou, Zonggang; Gao, Zhixian; Liu, Baiyun


    Most post-neurosurgical meningitis research has been focused on large cohorts with numerous cases followed over several years. However, the characteristics of post-neurosurgical meningitis in an entire single year are still unclear, and knowledge of these characteristics might influence the selection of appropriate antibiotics and therapeutic strategies for the successful management of this disease. Our aim is to obtain a better understanding of post-neurosurgical meningitis over a single entire year. Patients with positive meningitis cultures after neurosurgical operations in our hospital during the entire year of 2012 were included in the analysis. We report demographic characteristics, morbidity during different seasons, clinical and bacteriological profiles, sensitivity to antibiotics and causes of the post-neurosurgical meningitis infections in our cohort. Of the 6407 patients who underwent neurosurgical procedures during the study period, 146 developed post-neurosurgical meningitis and the overall incidence of meningitis was 2.28%. The incidence of meningitis was significantly higher in patients who underwent surgery in the autumn and winter than spring or summer (p=0.000). The most common organisms causing meningitis were Gram-positive bacteria, followed by the Klebsiella and Baumannii species. Compound sulfamethoxazole (52.6%) and vancomycin (10.5%) were the most active antibiotics against Gram-positive bacteria strains, whereas meropenem (43.8%) and polymyxin (18.8%) were active against Gram-negative bacillus strains. Post-neurosurgical meningitis usually occurs in the autumn and winter of the year in our hospital. Gram-positive organisms, which are sensitive to compound sulfamethoxazole and vancomycin, are the most common causative pathogens of post-neurosurgical meningitis in the northern mainland of China. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Model-based Software Engineering

    DEFF Research Database (Denmark)

    Kindler, Ekkart


    The vision of model-based software engineering is to make models the main focus of software development and to automatically generate software from these models. Part of that idea works already today. But, there are still difficulties when it comes to behaviour. Actually, there is no lack in models...

  14. Graph Model Based Indoor Tracking

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard; Lu, Hua; Yang, Bin


    The tracking of the locations of moving objects in large indoor spaces is important, as it enables a range of applications related to, e.g., security and indoor navigation and guidance. This paper presents a graph model based approach to indoor tracking that offers a uniform data management...

  15. Operative and consultative proportions of neurosurgical disease worldwide: estimation from the surgeon perspective. (United States)

    Dewan, Michael C; Rattani, Abbas; Baticulon, Ronnie E; Faruque, Serena; Johnson, Walter D; Dempsey, Robert J; Haglund, Michael M; Alkire, Blake C; Park, Kee B; Warf, Benjamin C; Shrime, Mark G


    OBJECTIVE The global magnitude of neurosurgical disease is unknown. The authors sought to estimate the surgical and consultative proportion of diseases commonly encountered by neurosurgeons, as well as surgeon case volume and perceived workload. METHODS An electronic survey was sent to 193 neurosurgeons previously identified via a global surgeon mapping initiative. The survey consisted of three sections aimed at quantifying surgical incidence of neurological disease, consultation incidence, and surgeon demographic data. Surgeons were asked to estimate the proportion of 11 neurological disorders that, in an ideal world, would indicate either neurosurgical operation or neurosurgical consultation. Respondent surgeons indicated their confidence level in each estimate. Demographic and surgical practice characteristics-including case volume and perceived workload-were also captured. RESULTS Eighty-five neurosurgeons from 57 countries, representing all WHO regions and World Bank income levels, completed the survey. Neurological conditions estimated to warrant neurosurgical consultation with the highest frequency were brain tumors (96%), spinal tumors (95%), hydrocephalus (94%), and neural tube defects (92%), whereas stroke (54%), central nervous system infection (58%), and epilepsy (40%) carried the lowest frequency. Similarly, surgery was deemed necessary for an average of 88% cases of hydrocephalus, 82% of spinal tumors and neural tube defects, and 78% of brain tumors. Degenerative spine disease (42%), stroke (31%), and epilepsy (24%) were found to warrant surgical intervention less frequently. Confidence levels were consistently high among respondents (lower quartile > 70/100 for 90% of questions), and estimates did not vary significantly across WHO regions or among income levels. Surgeons reported performing a mean of 245 cases annually (median 190). On a 100-point scale indicating a surgeon's perceived workload (0-not busy, 100-overworked), respondents selected a

  16. Model-based machine learning. (United States)

    Bishop, Christopher M


    Several decades of research in the field of machine learning have resulted in a multitude of different algorithms for solving a broad range of problems. To tackle a new application, a researcher typically tries to map their problem onto one of these existing methods, often influenced by their familiarity with specific algorithms and by the availability of corresponding software implementations. In this study, we describe an alternative methodology for applying machine learning, in which a bespoke solution is formulated for each new application. The solution is expressed through a compact modelling language, and the corresponding custom machine learning code is then generated automatically. This model-based approach offers several major advantages, including the opportunity to create highly tailored models for specific scenarios, as well as rapid prototyping and comparison of a range of alternative models. Furthermore, newcomers to the field of machine learning do not have to learn about the huge range of traditional methods, but instead can focus their attention on understanding a single modelling environment. In this study, we show how probabilistic graphical models, coupled with efficient inference algorithms, provide a very flexible foundation for model-based machine learning, and we outline a large-scale commercial application of this framework involving tens of millions of users. We also describe the concept of probabilistic programming as a powerful software environment for model-based machine learning, and we discuss a specific probabilistic programming language called Infer.NET, which has been widely used in practical applications.

  17. Working Conditions and Lifestyle of Female Surgeons Affiliated to the Japan Neurosurgical Society: Findings of Individual and Institutional Surveys


    FUJIMAKI, Takamitsu; SHIBUI, Soichiro; KATO, Yoko; MATSUMURA, Akira; YAMASAKI, Mami; DATE, Isao; HONGO, Kazuhiro; KURODA, Satoshi; MATSUMAE, Mitsunori; NAKAO, Naoyuki; SAKURADA, Kaori; SHIMOKAWA, Shoko; KAYAMA, Takamasa


    To investigate the working conditions of female neurosurgeons in Japan, two surveys were conducted by The Japan Neurosurgical Society: one involving female neurosurgeons themselves and the other involving the chiefs of neurosurgical departments. The responses were received from 224 (43.8%) female neurosurgeons and 496 (61.2%) departmental chiefs. About half (50.2%) of the female neurosurgeons were married and 39.2% had children (average number of children, 1.27). Their work was full-time in 8...

  18. Postoperative Central Nervous System Infection After Neurosurgery in a Modernized, Resource-Limited Tertiary Neurosurgical Center in South Asia. (United States)

    Chidambaram, Swathi; Nair, M Nathan; Krishnan, Shyam Sundar; Cai, Ling; Gu, Weiling; Vasudevan, Madabushi Chakravarthy


    Postoperative central nervous system infections (PCNSIs) are rare but serious complications after neurosurgery. The purpose of this study was to examine the prevalence and causative pathogens of PCNSIs at a modernized, resource-limited neurosurgical center in South Asia. A retrospective analysis was conducted of the medical records of all 363 neurosurgical cases performed between June 1, 2012, and June 30, 2013, at a neurosurgical center in South Asia. Data from all operative neurosurgical cases during the 13-month period were included. Cerebrospinal fluid (CSF) analysis indicated that 71 of the 363 surgical cases had low CSF glucose or CSF leukocytosis. These 71 cases were categorized as PCNSIs. The PCNSIs with positive CSF cultures (9.86%) all had gram-negative bacteria with Pseudomonas aeruginosa (n = 5), Escherichia coli (n = 1), or Klebsiella pneumoniae (n = 1). The data suggest a higher rate of death (P = 0.031), a higher rate of CSF leak (P < 0.001), and a higher rate of cranial procedures (P < 0.001) among the infected patients and a higher rate of CSF leak among the patients with culture-positive infections (P = 0.038). This study summarizes the prevalence, causative organism of PCNSI, and antibiotic usage for all of the neurosurgical cases over a 13-month period in a modernized yet resource-limited neurosurgical center located in South Asia. The results from this study highlight the PCNSI landscape in an area of the world that is often underreported in the neurosurgical literature because of the paucity of clinical neurosurgical research undertaken there. This study shows an increasing prevalence of gram-negative organisms in CSF cultures from PCNSIs, which supports a trend in the recent literature of increasing gram-negative bacillary meningitis. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Teleconferencing using multimedia messaging service (MMS) for long-range consultation of patients with neurosurgical problems in an acute situation. (United States)

    Waran, Vicknes; Selladurai, Benedict M; Bahuri, Nor Faizal Ahmad; George, George John K Thomas; Lim, Grace P S; Khine, Myo


    : We present our initial experience using a simple and relatively cost effective system using existing mobile phone network services and conventional handphones with built in cameras to capture carefully selected images from hard copies of scan images and transferring these images from a hospital without neurosurgical services to a university hospital with tertiary neurosurgical service for consultation and management plan. : A total of 14 patients with acute neurosurgical problems admitted to a general hospital in a 6 months period had their images photographed and transferred in JPEG format to a university neurosurgical unit. This was accompanied by a phone conference to discuss the scan and the patients' condition between the neurosurgeon and the referring physician. All images were also reviewed by a second independent neurosurgeon on a separate occasion to asses the agreement on the diagnosis and the management plan. : There were nine patients with acute head injury and five patients with acute nontraumatic neurosurgical problems. In all cases both neurosurgeons were in agreement that a diagnosis could be made on the basis of the images that were transferred. With respect to the management advice there were differences in opinion on three of the patients but these were considered to be minor. : Accurate diagnosis can be made on images of acute neurosurgical problems transferred using a conventional camera phone and meaningful decisions can be made on these images. This method of consultation also proved to be highly convenient and cost effective.

  20. Post-neurosurgical meningitis: Management of cerebrospinal fluid drainage catheters influences the evolution of infection


    Laura Soavi; Manuela Rosina; Roberto Stefini; Alessia Fratianni; Barbara Cadeo; Silvia Magri; Nicola Latronico; Marco Fontanella; Liana Signorini


    Background: In order to better define the pathogenic role of cerebrospinal fluid (CSF) drainage catheters in postoperative patients, we comparatively analyze the clinical course of device and non-device-related meningitis. Methods: This is an observational, partially prospective, study on consecutive adult patients who developed meningitis after undergoing neurosurgical procedures at the Neurosurgery and Neurointensive care Departments, Spedali Civili, Brescia, Italy, between January 1999...

  1. Current neurosurgical trainees' perception of the European Working Time Directive and shift work. (United States)

    Tait, M J; Fellows, G A; Pushpananthan, S; Sergides, Y; Papadopoulos, M C; Bell, B A


    The introduction of the shift system in response to the European Working Time Directive has had an enormous impact on the running of neurosurgical units in the UK. This study seeks to establish what provisions are currently in place for out of hours cover and what has been the effect of the introduction of shifts in three main areas: patient safety, training and 'work/life balance'. The on-call registrar at each UK neurosurgical unit was contacted by telephone. Data regarding current emergency provision were sought. Registrars who had worked both on-calls and the shift system during their career as a neurosurgical registrar were asked to make a comparison. Data were collected from all 33 UK units. Twenty-two still use a traditional 24-h on-call system. Twenty-one on-call rotas were classed as non-resident although 12/21 of those officially on non-resident rotas were in fact resident whilst on call. Twenty-two registrars had worked both systems as a neurosurgical registrar. Twenty-one (95.45%) felt that traditional on-calls gave better clinical exposure. Twenty-one (95.45%) felt that on-calls allowed the provision of better patient care. Nineteen (86.36%) felt that on-calls were safer. Thirteen (59.09%) reported that they were more tired when doing shift work than on-calls. Fourteen (63.63%) found that the on-call system gives more useful spare time and more time to deal with family commitments. Current neurosurgery registrars feel the shift system is less safe, harmful to training and worse in terms of work/life balance. More than one-third of units are claiming to have non-resident on-call systems in order to appear compliant with EWTD when registrars are in fact resident.

  2. Risk of Venous Thromboembolism and Operative Duration in Patients Undergoing Neurosurgical Procedures. (United States)

    Bekelis, Kimon; Labropoulos, Nicos; Coy, Shannon


    The association of operative duration with the risk of venous thromboembolism (VTE) has not been quantified in neurosurgery. To investigate the association of surgical duration for several neurosurgical procedures and the incidence of VTE. We performed a retrospective cohort study involving patients who underwent neurosurgical procedures from 2005 to 2012 and were registered in the American College of Surgeons National Quality Improvement Project registry. In order to control for confounding, we used multivariable regression models, and propensity score conditioning. During the study period, there were 94 747 patients, who underwent neurosurgical procedures, and met the inclusion criteria. Of these, 1358 (1.0%) developed VTE within 30 days postoperatively. Multivariable logistic regression demonstrated an association of longer operative duration with higher 30-day incidence of VTE (odds ratio [OR], 1.22; 95% confidence interval [CI], 1.19-1.25). Compared with procedures of moderate duration (third quintile, 40-60th percentile), patients undergoing the longest procedures (>80th percentile) had higher odds (OR, 3.15; 95% CI, 2.49-3.99) of developing VTE. The shortest procedures (<20th percentile) were associated with a decreased incidence of VTE (OR, 0.51; 95% CI, 0.27-0.76) in comparison to those of moderate duration. The same associations were present in propensity score-adjusted models, and models stratified by subgroups of cranial, spinal, peripheral nerve, and carotid procedures. In a cohort of patients from a national prospective surgical registry, increased operative duration was associated with increased incidence of VTE for neurosurgical procedures. These results can be used by neurosurgeons to inform operative management, and to stratify patients with regard to VTE risk. Copyright © 2016 by the Congress of Neurological Surgeons

  3. Neurosurgical outcomes after intracerebral hemorrhage: results of the Factor Seven for Acute Hemorrhagic Stroke Trial (FAST). (United States)

    Steiner, Thorsten; Vincent, Catherine; Morris, Stephen; Davis, Stephen; Vallejo-Torres, Laura; Christensen, Michael C


    The value of neurosurgical interventions after spontaneous intracerebral hemorrhage (SICH) is uncertain. We evaluated clinical outcomes in patients diagnosed with SICH within 3 hours of symptom onset who underwent hematoma evacuation or external ventricular drainage (EVD) of the hematoma in the Factor Seven for Acute Hemorrhagic Stroke Trial (FAST). FAST was a randomized, multicenter, double-blind, placebo-controlled trial conducted between May 2005 and February 2007 at 122 sites in 22 countries. Neurosurgical procedures (hematoma evacuation and external ventricular drainage) performed at any point after hospital admission were prospectively recorded. Clinical outcomes evaluated were post-SICH disability, as assessed by the modified Rankin Scale; neurologic impairment, as assessed by the National Institutes of Health Stroke Scale; and mortality at 90 days after SICH onset. The impact of neurosurgical procedures on clinical outcomes was evaluated using multivariate logistic regression analysis, controlling for relevant baseline characteristics. Fifty-five of 821 patients underwent neurosurgery. Patients who underwent hematoma evacuation or EVD were on average younger, had greater baseline neurologic impairment, and lower levels of consciousness compared with patients who did not undergo neurosurgery. After adjusting for these differences and other relevant baseline characteristics, we found that neurosurgery was generally associated with unfavorable outcomes at day 90. Among the patients who underwent hematoma evacuation, those with lobar ICH had less ICH expansion than those with deep gray matter ICH, and the smaller expansion was associated with lower mortality. ICH volume was substantially decreased in patients who underwent hematoma evacuation between 24 and 72 hours after hospital admission, and this was associated with better clinical outcome. In conclusion, a small number of patients who underwent neurosurgery in FAST exhibited no overall clinical benefit

  4. Attitudes of young neurosurgeons and neurosurgical residents towards euthanasia and physician-assisted suicide. (United States)

    Broekman, M L D; Verlooy, J S A


    Euthanasia and physician assisted suicide (PAS) are two controversial topics in neurosurgical practice. Personal attitudes and opinions on these important issues may vary between professionals, and may also depend on their location since current legislation differs between European countries. As these issues may have significant impact on clinical practice, the goal of the present study was to survey the opinions of neurosurgical residents and young neurosurgeons across Europe with respect to euthanasia and physician assisted suicide. We performed a survey among the participants of the European Association of Neurosurgical Societies (EANS) training courses (2011-2012), asking residents and young neurosurgeons nine questions on euthanasia and PAS. For the analysis of this survey, we divided all 295 participants into four European regions (North, South, East, West). We found that even though most residents are aware of regulations about euthanasia or PAS in their country or hospital, a substantial number were not aware of the regulations. We observed no significant differences in terms of their opinions on euthanasia and PAS among the four European regions. While most are actually in favor of euthanasia or PAS, if legally allowed, under appropriate circumstances, very few neurosurgeons would be willing to actively participate in these end-of-life practices. The results of this first survey on neurosurgical residents' attitudes towards euthanasia and PAS show that a significant number of residents is not familiar with national and/or local regulations regarding euthanasia and PAS. If legally allowed, most residents would be in favor of euthanasia and PAS, but only a minority would be willing to actively participate in these practices. We did not observe a difference in stances on euthanasia and PAS among residents from different regions in Europe.

  5. Interhospital Transfer of Neurosurgical Patients: Implications of Timing on Hospital Course and Clinical Outcomes. (United States)

    Holland, Christopher M; Lovasik, Brendan P; Howard, Brian M; McClure, Evan W; Samuels, Owen B; Barrow, Daniel L


    Interhospital transfer of neurosurgical patients is common; however, little is known about the impact of transfer parameters on clinical outcomes. Lower survival rates have been reported for patients admitted at night and on weekends in other specialties. Whether time or day of admission affects neurosurgical patient outcomes, specifically those transferred from other facilities, is unknown. To examine the impact of the timing of interhospital transfer on the hospital course and clinical outcomes of neurosurgical patients. All consecutive admissions of patients transferred to our adult neurosurgical service were retrospectively analyzed for a 1-year study period using data from a central transfer database and the electronic health record. Patients arrived more often at night (70.8%) despite an even distribution of transfer requests. The lack of transfer imaging did not affect length of stay, intervention times, or patient outcomes. Daytime arrivals had shorter total transfer time, but longer intenstive care unit and overall length of stay (8.7 and 11.6 days, respectively), worse modified Rankin Scale scores, lower rates of functional independence, and almost twice the mortality rate. Weekend admissions had significantly worse modified Rankin Scale scores and lower rates of functional independence. The timing of transfer arrivals, both by hour or day of the week, is correlated with the time to intervention, hospital course, and overall patient outcomes. Patients admitted during the weekend suffered worse functional outcomes and a trend towards increased mortality. While transfer logistics clearly impact patient outcomes, further work is needed to understand these complex relationships. Copyright © 2017 by the Congress of Neurological Surgeons.

  6. Post-operative shampoo effects in neurosurgical patients: a pilot experimental study. (United States)

    Palese, Alvisa; Moreale, Renzo; Noacco, Massimo; Pistrino, Flavia; Mastrolia, Irene; Sartor, Assunta; Scarparo, Claudio; Skrap, Miran


    Neurosurgical site infections are an important issue. Among the acknowledged preventive tactics, the non-shaving technique is well established in the neurosurgical setting. However, given that patient's hair around the surgical site may retain biologic material that emerges during the surgical procedure or that may simply become dirty, which may increase the risk of surgical site infections, if and when shampooing should be offered remains under debate. A pilot experimental study was undertaken from 2011 to 2012. A series of neurosurgical patients not affected by conditions that would increase the risk of post-operative infection were assigned randomly to the exposed group (receiving shampoo 72 h after surgical procedure) or control group (receiving standard dressing surveillance without shampooing). Comfort, surgical site contamination (measured as the number of colony-forming units [CFU]), and SSIs at 30 d after surgery were the main study outcomes. A total of 53 patients were included: 25 (47.2%) received a shampoo after 72 h whereas 28 (52.8%) received standard care. Patients who received a shampoo reported a similar level of comfort (average=8.04; standard deviation [SD] 1.05) compared with those receiving standard care (average 7.3; SD 3.2) although this was not statistically significant (p=0.345). No statistically significant difference emerged in the occurrence of surgical site contamination between the groups, and no SSIs were detected within 30 d. In our pilot study, the results of which are not generalizable because of the limited sample of patients involved, a gentle shampoo offered 72 h after the surgical procedure did not increase the SSIs occurrence or the contamination of the surgical site, although it may increase the perception of comfort by patients. Further studies are strongly recommended involving a larger sample size and designed to include more diversified neurosurgical patients undergoing surgical procedures in different centers.

  7. Red blood cell transfusion probability and associated costs in neurosurgical procedures. (United States)

    Barth, Martin; Weiss, Christel; Schmieder, Kirsten


    The extent of red blood cell units (RBC) needed for different neurosurgical procedures and the time point of their administration are widely unknown, which results in generously cross-matching prior to surgery. However, RBC are increasingly requested in the aging western populations, and blood donations are significantly reduced. Therefore, the knowledge of the extent and time point of administration of RBC is of major importance. This is a retrospective single center analysis. The incidence of RBC transfusion during surgery or within 48 h after surgery was analyzed for all neurosurgical patients within 3 years. Costs for cross-matched and transfused RBC were calculated and risk factors for RBC transfusion analyzed. The risk of intraoperative RBC administration was low for spinal and intracranial tumor resections (1.87%) and exceeded 10% only in spinal fusion procedures. This was dependent on the number of fused segments with an intraoperative transfusion risk of > 12.5% with fusion of more than three levels. Multiple logistic regression analysis showed a significantly increased risk for RBC transfusion for female gender (p = 0.006; OR 1.655), higher age (N = 4812; p < 0.0001; OR 1.028), and number of fused segments (N = 737; p < 0.0001; OR 1.433). Annual costs for cross-matching were 783,820.88 USD and for intraoperative RBC administration 121,322.13 USD. Neurosurgical procedures are associated with a low number of RBC needed intraoperatively. Only elective spine fusion procedures with ≥ 3 levels involved and AVM resections seem to require cross-matching of RBC. The present data may allow changing the preoperative algorithm of RBC cross-matching in neurosurgical procedures and help to save resources and costs.

  8. Safety of Running Two Rooms: A Systematic Review and Meta-Analysis of Overlapping Neurosurgical Procedures. (United States)

    Self, D Mitchell; Ilyas, Adeel; Stetler, William R


    Overlapping surgery, a long-standing practice within academic neurosurgery centers nationwide, has recently come under scrutiny from the government and media as potentially harmful to patients. Therefore, the objective of this systematic review and meta-analysis is to determine the safety of overlapping neurosurgical procedures. The authors performed a systematic review and meta-analysis in accordance with PRISMA guidelines. A review of PubMed and Medline databases was undertaken with the search phrase "overlapping surgery AND neurosurgery AND outcomes." Data regarding patient demographics, type of neurosurgical procedure, and outcomes and complications were extracted from each study. The principle summary measure was odds ratio (OR) of the association of overlapping versus non-overlapping surgery with outcomes. The literature search yielded a total of 36 studies, of which 5 studies met inclusion criteria and were included in this study. These studies included a total of 25,764 patients undergoing neurosurgical procedures. Overlapping surgery was associated with an increased likelihood of being discharged home (OR = 1.32; 95% CI 1.20 to 1.44; P < 0.001) and a reduced 30-day unexpected return to the operating room (OR = 0.79; 95% CI 0.72 to 0.87; P < 0.001). Overlapping surgery did not significantly affect OR of length of surgery, 30-day mortality, or 30-day readmission. Overlapping neurosurgical procedures were not associated with worse patient outcomes. Additional, prospective studies are needed to further assess the safety overlapping procedures. Copyright © 2018. Published by Elsevier Inc.

  9. Neurosurgical treatment of drug-resistant epilepsy on the basis of a fusion of MRI and SPECT images - case report

    International Nuclear Information System (INIS)

    Jurkiewicz, E.; Bekiesinska-Figatowska, M.; Misko, J.; Kaminska, A.; Kwiatkowski, S.; Terczynska, I.


    Background: Epilepsy concerns at least 0.5% of population and in most of the cases (approx. 70%) can be treated pharmacologically, which helps to prevent seizures. In all other patients, such a treatment does not produce the desired results. Their condition may require neurosurgical management. The aim of this work was to fuse anatomical MRI images and functional SPECT images in patients with drug resistant epilepsy, without structural changes on MRI or with changes so severe that it would be impossible to establish which ones are responsible for seizures. The authors presented a case of a child subjected to a neurosurgical procedure carried out on the basis of the fused MRI and SPECT images. Case Report: A seven-year-old boy with an extensive defect of the right hemisphere (cortical dysplasia with multiple balloon-like cells) operated on three times due to a history of treatment-resistant seizures present since the age of one. A subsequent MRI examination was performed with magnetic field intensity of 1.5 T, within a routine epilepsy protocol applying volumetric thin-slice T1-weighted images. Next, in the interictal period, a SPECT examination was performed with the use of the 99mT c-labelled ethyl cysteinate dimer ( 99mT cECD). For fusion and postprocessing, the following software was used: PMOD (Biomedical Image Quantification PMOD Technologies) with PFUS (Flexible Image Matching and Fusion Tool) and a program for a quantitative analysis of counts in the region of interest, so called VOI Constructor (Volume of Interest Constructor). On the basis of the fusion of images, the boy was subjected to the next operation procedure. The remaining fragments of the right frontal and parietal lobe adjacent to the occipital lobe were removed. Seizure remission was obtained and it was already 31 months long when we were writing this article. Conclusions: Owing to this multi-stage procedure, it was possible to avoid a total anatomical and functional hemispherectomy. This

  10. The Spectrum of Altmetrics in Neurosurgery: The Top 100 "Trending" Articles in Neurosurgical Journals. (United States)

    Wang, Justin; Alotaibi, Naif M; Ibrahim, George M; Kulkarni, Abhaya V; Lozano, Andres M


    Social media are increasingly used for the dissemination of scientific publications by most medical journals. The role of social media in increasing awareness of published works in neurosurgery has not been previously explored. Here, we present a qualitative analysis of the highest trending works in neurosurgery along with a correlation analysis with their social media metrics. We performed a comprehensive search for neurosurgical publications using the Altmetric database. The Altmetric database provides a weighted total score of all online mentions for an article received on Facebook, Twitter, blogs, and mainstream media sources. Our search was limited to articles published within the social media era (January 2010-January 2017). Descriptive and correlational statistics were performed for all articles. The top 100 articles in altmetrics were selected for qualitative analysis. A total of 5794 articles were included in this study. The average Altmetric score in neurosurgical articles was 4.7 (standard deviation ±22.4). Journals with a social media account had significantly higher Altmetric scores for their articles compared with those without an account (P articles in altmetrics belonged primarily to the Journal of Neurosurgery (33%) followed by Neurosurgery (29%). This is the first study that details the spectrum of Altmetric scores among neurosurgical journals. Social media presence for journals is important for greater outreach and engagement. Prediction of traditional citation using altmetrics data requires a future prospective study. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Risk of cataract among medical staff in neurosurgical department occupationally exposed to radiation

    International Nuclear Information System (INIS)

    Stankova-Mileva, I.; Vassileva, J.; Djounova, J.


    In this study we present the risk of cataract among medical staff in neurosurgical department occupationally exposed to radiation compared to those of non-radiation workers. Cataract is the most common degenerative opacity of the crystalline lens developing with aging. Other risk factors for cataract are: infrared and ultraviolet radiation, systemic diseases (diabetes, hypertonic disease), eye diseases (glaucoma, high myopia), drugs (steroids), etc. High risk of developing cataract we find among staff occupationally exposed to radiation during operations - interventional cardiologists and neurosurgeons. This study includes 30 people between 33 and 60 years of age working in neurosurgical department and control group (the same amount and age of people not exposed to radiation in their work). After visual acuity measurement, the lens was examined by retroillumination method (red reflex) and using a bio microscope. The patients were asked for presence of ocular and systemic diseases, eye trauma, drug, alcohol and tobacco abuse and for how many years they work in this department. There was one case with cataract among neurosurgeons. The doctor doesn't have eye or systemic diseases, doesn't take any drugs and is not alcohol or tobacco abuser. In the control group there were two persons with subcapsular cataract but they have diabetes. Radiation is one of the risk factors for cataract. Continuing of this epidemiological survey will provide further knowledge on the potential risk of occupational radiation-induced cataract among neurosurgical staff and will contribute for optimization of radiation protection. (authors)

  12. Estimating the Cost of Neurosurgical Procedures in a Low-Income Setting: An Observational Economic Analysis. (United States)

    Abdelgadir, Jihad; Tran, Tu; Muhindo, Alex; Obiga, Doomwin; Mukasa, John; Ssenyonjo, Hussein; Muhumza, Michael; Kiryabwire, Joel; Haglund, Michael M; Sloan, Frank A


    There are no data on cost of neurosurgery in low-income and middle-income countries. The objective of this study was to estimate the cost of neurosurgical procedures in a low-resource setting to better inform resource allocation and health sector planning. In this observational economic analysis, microcosting was used to estimate the direct and indirect costs of neurosurgical procedures at Mulago National Referral Hospital (Kampala, Uganda). During the study period, October 2014 to September 2015, 1440 charts were reviewed. Of these patients, 434 had surgery, whereas the other 1006 were treated nonsurgically. Thirteen types of procedures were performed at the hospital. The estimated mean cost of a neurosurgical procedure was $542.14 (standard deviation [SD], $253.62). The mean cost of different procedures ranged from $291 (SD, $101) for burr hole evacuations to $1,221 (SD, $473) for excision of brain tumors. For most surgeries, overhead costs represented the largest proportion of the total cost (29%-41%). This is the first study using primary data to determine the cost of neurosurgery in a low-resource setting. Operating theater capacity is likely the binding constraint on operative volume, and thus, investing in operating theaters should achieve a higher level of efficiency. Findings from this study could be used by stakeholders and policy makers for resource allocation and to perform economic analyses to establish the value of neurosurgery in achieving global health goals. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. [Program for lowering the incidence of pressure sores in neurosurgical patients]. (United States)

    Chang, Chau-Hui; Chen, Hui-Ling; Chen, Hsiang-Chi


    Pressure sores are one of the well known problems that occur in hospitals. As the literature on the subject indicates, a lot of money is expended in managing this problem every year, and 12-66% of pressure sores are caused during surgery. Patients who undergo neurosurgical procedures are susceptible to pressure sores because of lengthy operations. We collected data on patients with pressure sores who underwent surgery between May 2004 and August 2004, and found that the incidence of pressure sore in neurosurgical patients was 9.5%, which was the highest among all surgical patients. This project was developed to solve the problem of pressure sores by setting up standard preventive procedures, a nursing follow up system and continuing education courses, and utilizing cotton rolls to pad sites of pressure sores. The incidence of pressure sore in neurosurgical patients was reduced from 9.5% to 7% after the improvement project was carried out. The more concerned nurses are about pressure sores, the better the quality of operative nursing care.

  14. Early years neurosurgical training in the era of the European Working Time Directive. (United States)

    Kirkman, Matthew A; Watkins, Laurence D; Kitchen, Neil D; Sethi, Huma


    The past decade has seen significant changes to the face of neurosurgical training in the United Kingdom, driven in part by an increasing focus on patient safety and the introduction of Modernising Medical Careers and the European Working Time Directive (EWTD). Recent reforms to neurosurgical training over the past few years have resulted in creation of an 8-year 'run-through' training programme. In this programme, early years (ST1 and ST2) trainees often lack dedicated time for elective theatre lists and outpatient clinics. Further, any time spent in theatre and clinics is often with different teams. Here we describe a training model for early years trainees at the National Hospital for Neurology and Neurosurgery, who are given the responsibilities traditionally associated with a more senior trainee including dedicated weekly theatre and clinic time under the supervision of a single consultant, in addition to out of hours experience. The advantages and considerations for implementing this model are discussed, including the benefit of guidance under a single consultant in the early stages of training, along with key educational concepts necessary for understanding its utility. We feel that this is an effective model for junior neurosurgical training in the EWTD era, expediting the trainee's development of key technical and non-technical skills, with potentially significant rewards for patient, trainee and trainer. National implementation of this model should be considered.

  15. Effect of mobile laminar airflow units on airborne bacterial contamination during neurosurgical procedures. (United States)

    von Vogelsang, A-C; Förander, P; Arvidsson, M; Löwenhielm, P


    Surgical site infections (SSIs) after neurosurgery are potentially life-threatening and entail great costs. SSIs may occur from airborne bacteria in the operating room, and ultraclean air is desired during infection-prone cleaning procedures. Door openings and the number of persons present in the operating room affect the air quality. Mobile laminar airflow (MLAF) units, with horizontal laminar airflow, have previously been shown to reduce airborne bacterial contamination. To assess the effect of MLAF units on airborne bacterial contamination during neurosurgical procedures. In a quasi-experimental design, bacteria-carrying particles (colony-forming units: cfu) during neurosurgical procedures were measured with active air-sampling in operating rooms with conventional turbulent ventilation, and with additional MLAF units. The MLAF units were shifted between operating rooms monthly. Colony-forming unit count and bacterial species detection were conducted after incubation. Data was collected for a period of 18 months. A total of 233 samples were collected during 45 neurosurgical procedures. The use of MLAF units significantly reduced the numbers of cfu in the surgical site area (P neurosurgery to ultraclean air levels. MLAF units are valuable when the main operating room ventilation system is unable to produce ultraclean air in infection-prone clean neurosurgery. Copyright © 2018 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  16. Environmental and Clinical Risk Factors for Delirium in a Neurosurgical Center: A Prospective Study. (United States)

    Matano, Fumihiro; Mizunari, Takayuki; Yamada, Keiko; Kobayashi, Shiro; Murai, Yasuo; Morita, Akio


    Few reports of delirium-related risk factors have focused on environmental risk factors and clinical risk factors, such as white matter signal abnormalities on magnetic resonance imaging fluid attenuated inversion recovery images. We prospectively enrolled 253 patients admitted to our neurosurgical center between December 2014 and June 2015 and analyzed 220 patients (100 male patients; mean age, 64.1 years; age range, 17-92 years). An Intensive Care Delirium Screening Checklist score ≥4 points indicated delirium. We evaluated patient factors consisting of baseline characteristics and related factors, such as white matter lesions (WMLs), as well as the surrounding environment. Delirium occurred in 29/220 cases (13.2%). Regarding baseline characteristics, there were significant statistical correlations between delirium and age (P = 0.0187), Hasegawa Dementia Scale-Revised score (P = 0.0022) on admission, and WMLs (P delirium and stay in a neurosurgical care unit (P = 0.0245). Multivariate logistic regression analyses showed statistically significant correlations of delirium with WMLs (P delirium (P = 0.026). WMLs in patients and the surrounding environment are risk factors for delirium in a neurosurgical center. To prevent delirium, clinicians must recognize risk factors, such as high-grade WMLs, and manage environmental factors. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. A model-based risk management framework

    Energy Technology Data Exchange (ETDEWEB)

    Gran, Bjoern Axel; Fredriksen, Rune


    The ongoing research activity addresses these issues through two co-operative activities. The first is the IST funded research project CORAS, where Institutt for energiteknikk takes part as responsible for the work package for Risk Analysis. The main objective of the CORAS project is to develop a framework to support risk assessment of security critical systems. The second, called the Halden Open Dependability Demonstrator (HODD), is established in cooperation between Oestfold University College, local companies and HRP. The objective of HODD is to provide an open-source test bed for testing, teaching and learning about risk analysis methods, risk analysis tools, and fault tolerance techniques. The Inverted Pendulum Control System (IPCON), which main task is to keep a pendulum balanced and controlled, is the first system that has been established. In order to make risk assessment one need to know what a system does, or is intended to do. Furthermore, the risk assessment requires correct descriptions of the system, its context and all relevant features. A basic assumption is that a precise model of this knowledge, based on formal or semi-formal descriptions, such as UML, will facilitate a systematic risk assessment. It is also necessary to have a framework to integrate the different risk assessment methods. The experiences so far support this hypothesis. This report presents CORAS and the CORAS model-based risk management framework, including a preliminary guideline for model-based risk assessment. The CORAS framework for model-based risk analysis offers a structured and systematic approach to identify and assess security issues of ICT systems. From the initial assessment of IPCON, we also believe that the framework is applicable in a safety context. Further work on IPCON, as well as the experiences from the CORAS trials, will provide insight and feedback for further improvements. (Author)

  18. GSFLOW - Coupled Ground-Water and Surface-Water Flow Model Based on the Integration of the Precipitation-Runoff Modeling System (PRMS) and the Modular Ground-Water Flow Model (MODFLOW-2005) (United States)

    Markstrom, Steven L.; Niswonger, Richard G.; Regan, R. Steven; Prudic, David E.; Barlow, Paul M.


    The need to assess the effects of variability in climate, biota, geology, and human activities on water availability and flow requires the development of models that couple two or more components of the hydrologic cycle. An integrated hydrologic model called GSFLOW (Ground-water and Surface-water FLOW) was developed to simulate coupled ground-water and surface-water resources. The new model is based on the integration of the U.S. Geological Survey Precipitation-Runoff Modeling System (PRMS) and the U.S. Geological Survey Modular Ground-Water Flow Model (MODFLOW). Additional model components were developed, and existing components were modified, to facilitate integration of the models. Methods were developed to route flow among the PRMS Hydrologic Response Units (HRUs) and between the HRUs and the MODFLOW finite-difference cells. This report describes the organization, concepts, design, and mathematical formulation of all GSFLOW model components. An important aspect of the integrated model design is its ability to conserve water mass and to provide comprehensive water budgets for a location of interest. This report includes descriptions of how water budgets are calculated for the integrated model and for individual model components. GSFLOW provides a robust modeling system for simulating flow through the hydrologic cycle, while allowing for future enhancements to incorporate other simulation techniques.

  19. Integration

    DEFF Research Database (Denmark)

    Emerek, Ruth


    Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration......Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration...

  20. An Analysis of Publication Productivity During Residency for 1506 Neurosurgical Residents and 117 Residency Departments in North America. (United States)

    Khan, Nickalus R; Saad, Hassan; Oravec, Chesney S; Norrdahl, Sebastian P; Fraser, Brittany; Wallace, David; Lillard, Jock C; Motiwala, Mustafa; Nguyen, Vincent N; Lee, Siang Liao; Jones, Anna V; Ajmera, Sonia; Kalakoti, Piyush; Dave, Pooja; Moore, Kenneth A; Akinduro, Olutomi; Nyenwe, Emmanuel; Vaughn, Brandy; Michael, L Madison; Klimo, Paul


    Bibliometrics is defined as the study of statistical and mathematical methods used to quantitatively analyze scientific literature. The application of bibliometrics in neurosurgery continues to evolve. To calculate a number of publication productivity measures for almost all neurosurgical residents and departments within North America. These measures were correlated with survey results on the educational environment within residency programs. During May to June 2017, data were collected from departmental websites and Scopus to compose a bibliometric database of neurosurgical residents and residency programs. Data related to authorship value and study content were collected on all articles published by residents. A survey of residency program research and educational environment was administered to program directors and coordinators; results were compared with resident academic productivity. The median number of publications in residency was 3; median h-index and Resident index were 1 and 0.17 during residency, respectively. There was a statistically significant difference in academic productivity among male neurosurgical residents compared with females. The majority of articles published were tier 1 clinical articles. Residency program research support was significantly associated with increased resident productivity (P productivity. This study represents the most comprehensive bibliometric assessment of neurosurgical resident academic productivity during training to date. New benchmarks for individual and department academic productivity are provided. A supportive research environment for neurosurgical residents is associated with increased academic productivity, but a scholarly activity requirement was, surprisingly, not shown to have a positive effect.

  1. Issues in practical model-based diagnosis

    NARCIS (Netherlands)

    Bakker, R.R.; Bakker, R.R.; van den Bempt, P.C.A.; van den Bempt, P.C.A.; Mars, Nicolaas; Out, D.-J.; Out, D.J.; van Soest, D.C.; van Soes, D.C.


    The model-based diagnosis project at the University of Twente has been directed at improving the practical usefulness of model-based diagnosis. In cooperation with industrial partners, the research addressed the modeling problem and the efficiency problem in model-based reasoning. Main results of

  2. Model-based sensor diagnosis

    International Nuclear Information System (INIS)

    Milgram, J.; Dormoy, J.L.


    Running a nuclear power plant involves monitoring data provided by the installation's sensors. Operators and computerized systems then use these data to establish a diagnostic of the plant. However, the instrumentation system is complex, and is not immune to faults and failures. This paper presents a system for detecting sensor failures using a topological description of the installation and a set of component models. This model of the plant implicitly contains relations between sensor data. These relations must always be checked if all the components are functioning correctly. The failure detection task thus consists of checking these constraints. The constraints are extracted in two stages. Firstly, a qualitative model of their existence is built using structural analysis. Secondly, the models are formally handled according to the results of the structural analysis, in order to establish the constraints on the sensor data. This work constitutes an initial step in extending model-based diagnosis, as the information on which it is based is suspect. This work will be followed by surveillance of the detection system. When the instrumentation is assumed to be sound, the unverified constraints indicate errors on the plant model. (authors). 8 refs., 4 figs

  3. Predicting Resident Performance from Preresidency Factors: A Systematic Review and Applicability to Neurosurgical Training. (United States)

    Zuckerman, Scott L; Kelly, Patrick D; Dewan, Michael C; Morone, Peter J; Yengo-Kahn, Aaron M; Magarik, Jordan A; Baticulon, Ronnie E; Zusman, Edie E; Solomon, Gary S; Wellons, John C


    Neurosurgical educators strive to identify the best applicants, yet formal study of resident selection has proved difficult. We conducted a systematic review to answer the following question: What objective and subjective preresidency factors predict resident success? PubMed, ProQuest, Embase, and the CINAHL databases were queried from 1952 to 2015 for literature reporting the impact of preresidency factors (PRFs) on outcomes of residency success (RS), among neurosurgery and all surgical subspecialties. Due to heterogeneity of specialties and outcomes, a qualitative summary and heat map of significant findings were constructed. From 1489 studies, 21 articles met inclusion criteria, which evaluated 1276 resident applicants across five surgical subspecialties. No neurosurgical studies met the inclusion criteria. Common objective PRFs included standardized testing (76%), medical school performance (48%), and Alpha Omega Alpha (43%). Common subjective PRFs included aggregate rank scores (57%), letters of recommendation (38%), research (33%), interviews (19%), and athletic or musical talent (19%). Outcomes of RS included faculty evaluations, in-training/board exams, chief resident status, and research productivity. Among objective factors, standardized test scores correlated well with in-training/board examinations but poorly correlated with faculty evaluations. Among subjective factors, aggregate rank scores, letters of recommendation, and athletic or musical talent demonstrated moderate correlation with faculty evaluations. Standardized testing most strongly correlated with future examination performance but correlated poorly with faculty evaluations. Moderate predictors of faculty evaluations were aggregate rank scores, letters of recommendation, and athletic or musical talent. The ability to predict success of neurosurgical residents using an evidence-based approach is limited, and few factors have correlated with future resident performance. Given the importance of

  4. Improving neurosurgical communication and reducing risk and registrar burden using a novel online database referral platform. (United States)

    Matloob, Samir A; Hyam, Jonathan A; Thorne, Lewis; Bradford, Robert


    Documentation of urgent referrals to neurosurgical units and communication with referring hospitals is critical for effective handover and appropriate continuity of care within a tertiary service. Referrals to our neurosurgical unit were audited and we found that the majority of referrals were not documented and this led to more calls to the on-call neurosurgery registrar regarding old referrals. We implemented a new referral system in an attempt to improve documentation of referrals, communication with our referring hospitals and to professionalise the service we offer them. During a 14-day period, number of bleeps, missed bleeps, calls discussing new referrals and previously processed referrals were recorded. Whether new referrals were appropriately documented and referrers received a written response was also recorded. A commercially provided secure cloud-based data archiving telecommunications and database platform for referrals was subsequently introduced within the Trust and the questionnaire repeated during another 14-day period 1 year after implementation. Missed bleeps per day reduced from 16% (SD ± 6.4%) to 9% (SD ± 4.8%; df = 13, paired t-tests p = 0.007) and mean calls per day clarifying previous referrals reduced from 10 (SD ± 4) to 5 (SD ± 3.5; df = 13, p = 0.003). Documentation of new referrals increased from 43% (74/174) to 85% (181/210), and responses to referrals increased from 74% to 98%. The use of a secure cloud-based data archiving telecommunications and database platform significantly increased the documentation of new referrals. This led to fewer missed bleeps and fewer calls about old referrals for the on call registrar. This system of documenting referrals results in improved continuity of care for neurosurgical patients, a significant reduction in risk for Trusts and a more efficient use of Registrar time.

  5. Neuro-critical care: a valuable placement during foundation and early neurosurgical training. (United States)

    Dyson, Edward W; Kolias, Angelos G; Burnstein, Rowan M; Hutchinson, Peter J A; Garnett, Matthew R; Menon, David K; Trivedi, Rikin A


    Neurosciences critical care units (NCCUs) present a unique opportunity to junior trainees in neurosurgery as well as foundation trainees looking to gain experience in the management of critically ill patients with neurological conditions. Placements in NCCUs are undertaken in the early years of neurosurgical training or during neurosciences themed foundation programmes. We sought to quantify the educational benefits of such placements from the trainee perspective. Thirty-two trainees who had undertaken placements at Foundation Year 2 (FY2) to Specialty Trainee Year 3 (ST3) level between August 2009 and April 2013 were invited to take part in an online questionnaire survey. Competence in individual skills was self-rated on a ranked scale from one (never observed) to five (performed unsupervised) both before and after the placement. Trainees were also asked a series of questions pertaining to their ability to manage common neurosurgical conditions, as well as the perceived educational rigour of their placement. Twenty-three responses were received. Eighteen responses were from FY2s and seven were from ST1-3 level trainees. Following their placements, 100% of respondents felt better equipped to deal with neurosurgical and neurological emergencies and cranial trauma. Most felt better equipped to manage hydrocephalus (95.7%), polytrauma patients (95.7%), spontaneous intracranial haemorrhage (91.3%) and spinal trauma (82.6%). Significant increases were seen in experience in all practical skills assessed. These included central venous catheterisation (p training programme as well as in the Foundation Programme. This supports the incorporation of a four- to six-month NCCU rotation in early years training as educationally valuable.

  6. Effects of Transcranial Direct-Current Stimulation on Neurosurgical Skill Acquisition: A Randomized Controlled Trial. (United States)

    Ciechanski, Patrick; Cheng, Adam; Lopushinsky, Steven; Hecker, Kent; Gan, Liu Shi; Lang, Stefan; Zareinia, Kourosh; Kirton, Adam


    Recent changes in surgical training environments may have limited opportunities for trainees to gain proficiency in skill. Complex skills such as neurosurgery require extended periods of training. Methods to enhance surgical training are required to overcome duty-hour restrictions, to ensure the acquisition of skill proficiency. Transcranial direct-current stimulation (tDCS) can enhance motor skill learning, but is untested in surgical procedural training. We aimed to determine the effects of tDCS on simulation-based neurosurgical skill acquisition. Medical students were trained to acquire tumor resection skills using a virtual reality neurosurgical simulator. The primary outcome of change in tumor resection was scored at baseline, over 8 repetitions, post-training, and again at 6 weeks. Participants received anodal tDCS or sham over the primary motor cortex. Secondary outcomes included changes in brain resected, resection effectiveness, duration of excessive forces (EF) applied, and resection efficiency. Additional outcomes included tDCS tolerability. Twenty-two students consented to participate, with no dropouts over the course of the trial. Participants receiving tDCS intervention increased the amount of tumor resected, increased the effectiveness of resection, reduced the duration of EF applied, and improved resection efficiency. Little or no decay was observed at 6 weeks in both groups. No adverse events were documented, and sensation severity did not differ between stimulation groups. The addition of tDCS to neurosurgical training may enhance skill acquisition in a simulation-based environment. Trials of additional skills in high-skill residents, and translation to nonsimulated performance are needed to determine the potential utility of tDCS in surgical training. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Pilot Use of a Novel Tool to Assess Neurosurgical Capacity in Uganda. (United States)

    Ploss, Brittany; Abdelgadir, Jihad; Smith, Emily R; Fuller, Anthony; Nickenig Vissoci, Joao Ricardo; Muhindo, Alex; Galukande, Moses; Haglund, Michael M


    There is a significant burden of unmet surgical need in many low- and middle-income countries (>80% in parts of Africa). This need is even larger for specialties such as neurosurgery. Surgical capacity tools have been developed and used to assess needs and plan for resource allocation. This study piloted a new tool to assess neurosurgical capacity and describes its use. A surgical capacity tool was adapted to assess neurosurgical capacity. An expert panel of neurosurgeons and researchers reviewed the Surgeons OverSeas PIPES (personnel, infrastructure, procedures, equipment, and supplies) assessment and added additional items essential to perform common neurosurgery procedures. This tool was then piloted at 3 public hospitals in Uganda and each hospital was given a score of neurosurgical capacity. At 1 hospital, 3 respondents were asked to answer the survey to assess reliability. The hospital with the largest neurosurgery caseload and 5 neurosurgeons scored the highest on our survey, followed by a regional hospital with 1 practicing neurosurgeon. The third hospital, without a neurosurgeon, scored the lowest on the scale. At the hospital that completed the reliability assessment, scores were varied between respondents. NeuroPIPES survey scores were in keeping with the number of neurosurgeons and respective caseloads of each hospital. However, the variation in scores between respondents at the same hospital suggests that adaptations could be made to the tool that may improve reliability and validity. The methodology used to create NeuroPIPES may be successfully applied to a variety of other surgical subspecialties for similar assessments. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Cost and usage patterns of antibiotics in a tertiary care neurosurgical unit

    Directory of Open Access Journals (Sweden)

    Manish Singh Sharma


    Full Text Available Objectives: The routine use of prophylactic antibiotics in neurosurgery has been shown to significantly reduce surgical site infection rates. The documentation of non-surgical site, nosocomial infections in neurosurgical patients remains limited, despite this being a stimulus for prolific antibiotic usage. The actual quantum of antibiotic use in neurosurgery and its role in infection control remain both undocumented and controversial. The authors address this issue with a cost-effectiveness study using historical controls. Materials and Methods: Bacteriologically positive body fluid samples were used to quantify infection rates in the year 2006 and compared with those in the year 1997. Itemized drug lists obtained from dedicated neurosurgical intensive care units and wards were used to quantify antibiotic usage and calculate their costs. Results were compared using both historical and internal controls. The monetary conversion factor used was INR 40=US$1. Results: A total of 3114 consecutive elective and emergency neurosurgical procedures were performed during the study period. 329 patients (10.6% were recorded to have bacteriologically positive body fluid samples, and 100,250 units of antibiotics were consumed costing Rs. 14,378,227.5 ($359,455.7. On an average, an operated patient received 32.2 units of antibiotics valued at Rs. 4,617 ($115.4. The crude infection rates were recorded to have reduced significantly in comparison to 1997, but did not differ between mirror intra-departmental units with significantly different antibiotic usage. Conclusions: Antibiotics accounted for 31% of the per capita cost of consumables for performing a craniotomy in the year 2006. This estimate should be factored into projecting future package costs.

  9. [Integrity]. (United States)

    Gómez Rodríguez, Rafael Ángel


    To say that someone possesses integrity is to claim that that person is almost predictable about responses to specific situations, that he or she can prudentially judge and to act correctly. There is a closed interrelationship between integrity and autonomy, and the autonomy rests on the deeper moral claim of all humans to integrity of the person. Integrity has two senses of significance for medical ethic: one sense refers to the integrity of the person in the bodily, psychosocial and intellectual elements; and in the second sense, the integrity is the virtue. Another facet of integrity of the person is la integrity of values we cherish and espouse. The physician must be a person of integrity if the integrity of the patient is to be safeguarded. The autonomy has reduced the violations in the past, but the character and virtues of the physician are the ultimate safeguard of autonomy of patient. A field very important in medicine is the scientific research. It is the character of the investigator that determines the moral quality of research. The problem arises when legitimate self-interests are replaced by selfish, particularly when human subjects are involved. The final safeguard of moral quality of research is the character and conscience of the investigator. Teaching must be relevant in the scientific field, but the most effective way to teach virtue ethics is through the example of the a respected scientist.

  10. Model based risk assessment - the CORAS framework

    Energy Technology Data Exchange (ETDEWEB)

    Gran, Bjoern Axel; Fredriksen, Rune; Thunem, Atoosa P-J.


    Traditional risk analysis and assessment is based on failure-oriented models of the system. In contrast to this, model-based risk assessment (MBRA) utilizes success-oriented models describing all intended system aspects, including functional, operational and organizational aspects of the target. The target models are then used as input sources for complementary risk analysis and assessment techniques, as well as a basis for the documentation of the assessment results. The EU-funded CORAS project developed a tool-supported methodology for the application of MBRA in security-critical systems. The methodology has been tested with successful outcome through a series of seven trial within the telemedicine and ecommerce areas. The CORAS project in general and the CORAS application of MBRA in particular have contributed positively to the visibility of model-based risk assessment and thus to the disclosure of several potentials for further exploitation of various aspects within this important research field. In that connection, the CORAS methodology's possibilities for further improvement towards utilization in more complex architectures and also in other application domains such as the nuclear field can be addressed. The latter calls for adapting the framework to address nuclear standards such as IEC 60880 and IEC 61513. For this development we recommend applying a trial driven approach within the nuclear field. The tool supported approach for combining risk analysis and system development also fits well with the HRP proposal for developing an Integrated Design Environment (IDE) providing efficient methods and tools to support control room systems design. (Author)

  11. Neurosurgical conditions and procedures in infancy are associated with mortality and academic performances in adolescence

    DEFF Research Database (Denmark)

    Hansen, Tom G; Pedersen, Jacob K; Henneberg, Steen W


    at assessing the impact of specific neurosurgical conditions and procedures in infancy on mortality and academic achievements in adolescence. METHODS: A nationwide unselected register-based follow-up study of the Danish birth cohorts 1986-1990 compared academic performances of all children having undergone.......00001, P = 0.000077, and P = 0.000064). CONCLUSION: Neurosurgery in infancy was associated with high mortality and significantly impaired academic achievements in adolescence. When studying anesthesia-related neurotoxicity and the developing brain, focus on specific surgeries/conditions is important...

  12. Intraoperative intrinsic optical imaging of human somatosensory cortex during neurosurgical operations. (United States)

    Sato, Katsushige; Nariai, Tadashi; Momose-Sato, Yoko; Kamino, Kohtaro


    Intrinsic optical imaging as developed by Grinvald et al. is a powerful technique for monitoring neural function in the in vivo central nervous system. The advent of this dye-free imaging has also enabled us to monitor human brain function during neurosurgical operations. We briefly describe our own experience in functional mapping of the human somatosensory cortex, carried out using intraoperative optical imaging. The maps obtained demonstrate new additional evidence of a hierarchy for sensory response patterns in the human primary somatosensory cortex.

  13. Effects of computer tomography on diagnosis of neurological and neurosurgical diseases

    International Nuclear Information System (INIS)

    Katzner, E.


    Computer tomography is presently the primary procedure for correct diagnosis of many neurological and neurosurgical diseases. Other expensive and riskier diagnostic methods have become superfluous. Selective and clearly indicated application of the undoubtedly expensive computer tomography ultimately spares unnecessary costs for hospitalization and less conclusive examination methods. Wheras the indications in the craniocerebral region can now be considered confirmed, spinal computer tomography is still in the development stage. With certain indications, e.g. in prolapsed lumbar intervertebral disk, a similar performance to that of CT can be obtained with myelography, so that the latter method is likely to be superceded by computer tomography. (orig.) [de

  14. Statement of Ethics in Neurosurgery of the World Federation of Neurosurgical Societies. (United States)

    Umansky, Felix; Black, Peter L; DiRocco, Concenzio; Ferrer, Enrique; Goel, Atul; Malik, Ghaus M; Mathiesen, Tiit; Mendez, Ivar; Palmer, James D; Juanotena, Jorge Rodriguez; Fraifeld, Shifra; Rosenfeld, Jeffrey V


    This Statement of Ethics in Neurosurgery was developed by the Committee for Ethics and Medico-Legal Affairs of the World Federation of Neurosurgical Societies to help neurosurgeons resolve problems in the treatment of individual patients and meet obligations to the larger society. This document is intended as a framework rather than a set of rules. It cannot cover every situation and should be used with flexibility. However, it is our intent that the fundamental principles enunciated here should serve as a guide in the day-to-day practice of neurosurgery. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. 基于产业价值链整合探析移动互联网企业盈利模式%Integration of Mobile Internet Companies Profit Model Based on Industry Value Chain

    Institute of Scientific and Technical Information of China (English)



    Mobile Internet companies play the role of resource integration in the industry chain.Based on the industry value chain,mobile Internet companies and operators,content providers and equipment manufacturers show a high degree of association between the cone,and then the paper analyses factors that affect their profitability from the user,the value chain positioning,products and services,cross-border competition and cooperation,and explores the mobile Internet business profit model from pay for content,advertising media,product distribution and affiliate marketing interests share.The author believes that the mobile Internet companies must integrate internal and external resources to achieve profitability,to work closely with the various aspects of the industry chain,in order to ultimately achieve customer value.%移动互联网企业在产业链上扮演着资源整合的角色。基于产业价值链,移动互联网企业与运营商、内容供应商及设备制造商之间呈关联度高的锥型关系,进而从用户价值、价值链定位、产品与服务、跨界竞合四方面分析影响其盈利的因素,并从内容付费、广告媒介、产品分销以及联盟营销与利益分享四方面探析移动互联网企业的盈利模式。笔者认为,移动互联网企业要实现盈利,必须整合企业内外资源,与产业链各环节紧密合作,才能最终实现用户价值。

  16. Model based process-product design and analysis

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    This paper gives a perspective on modelling and the important role it has within product-process design and analysis. Different modelling issues related to development and application of systematic model-based solution approaches for product-process design is discussed and the need for a hybrid...... model-based framework is highlighted. This framework should be able to manage knowledge-data, models, and associated methods and tools integrated with design work-flows and data-flows for specific product-process design problems. In particular, the framework needs to manage models of different types......, forms and complexity, together with their associated parameters. An example of a model-based system for design of chemicals based formulated products is also given....

  17. A comparative analysis of neurosurgical online education materials to assess patient comprehension. (United States)

    Agarwal, Nitin; Chaudhari, Amit; Hansberry, David R; Tomei, Krystal L; Prestigiacomo, Charles J


    Americans have increasingly utilized the internet as a first-line resource for a variety of information, including healthcare-oriented materials. Therefore, these online resources should be written at a level the average American can understand. Patient education resources specifically written for and available to the public were downloaded from the American Association of Neurological Surgeons website and assessed for their level of readability using the Flesch Reading Ease, Flesch-Kincaid Grade Level, Simple Measure of Gobbledygook Grading, Coleman-Liau Index, and Gunning-Fog Index. A total of 71 subsections from different neurosurgical specialties were reviewed, including Cerebrovascular, Spine and Peripheral Nerves, Neurotrauma and Critical Care, Pain, Pediatric, Stereotactic and Functional, and Tumor material. All neurosurgical subspecialty education material provided on the American Association of Neurological Surgeons website was uniformly written at a level that was too high, as assessed by all modalities. In order to reach a larger patient population, patient education materials on the American Association of Neurological Surgeons website should be revised with the goal of simplifying readability. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Neurosurgical hand-held optical coherence tomography (OCT) forward-viewing probe (United States)

    Sun, Cuiru; Lee, Kenneth K. C.; Vuong, Barry; Cusimano, Michael; Brukson, Alexander; Mariampillai, Adrian; Standish, Beau A.; Yang, Victor X. D.


    A prototype neurosurgical hand-held optical coherence tomography (OCT) imaging probe has been developed to provide micron resolution cross-sectional images of subsurface tissue during open surgery. This new ergonomic hand-held probe has been designed based on our group's previous work on electrostatically driven optical fibers. It has been packaged into a catheter probe in the familiar form factor of the clinically accepted Bayonet shaped neurosurgical non-imaging Doppler ultrasound probes. The optical design was optimized using ZEMAX simulation. Optical properties of the probe were tested to yield an ~20 um spot size, 5 mm working distance and a 3.5 mm field of view. The scan frequency can be increased or decreased by changing the applied voltage. Typically a scan frequency of less than 60Hz is chosen to keep the applied voltage to less than 2000V. The axial resolution of the probe was ~15 um (in air) as determined by the OCT system. A custom-triggering methodology has been developed to provide continuous stable imaging, which is crucial for clinical utility. Feasibility of this probe, in combination with a 1310 nm swept source OCT system was tested and images are presented to highlight the usefulness of such a forward viewing handheld OCT imaging probe. Knowledge gained from this research will lay the foundation for developing new OCT technologies for endovascular management of cerebral aneurysms and transsphenoidal neuroendoscopic treatment of pituitary tumors.

  19. Evaluating functional MRI procedures for assessing hemispheric language dominance in neurosurgical patients

    International Nuclear Information System (INIS)

    Baciu, M.V.; Watson, J.M.; Maccotta, L.; McDermott, K.B.; Buckner, R.L.; Gilliam, F.G.; Ojemann, J.G.


    Two methods of quantifying hemispheric language dominance (HLD) in neurosurgical patients are compared: (1) an average magnitudes (AM) method, which is a calculation of the average signal intensity variation in regions of interest for each patient that were predefined in a group analysis for each task, and (2) a lateralization indices (LI) method, which is based on the number of activated pixels in regions of interest predefined in each individual patient. Four language tasks [a living/nonliving (LNL) judgment, word stem completion (WSC), semantic associate (SA) and a phonological associate (PA) task] were compared with ''gold standard'' measures such as the Wada test or electrocortical stimulation. Results showed that the LI method was more accurate (73% agreement with gold standard methods) than the AM method (only 40% agreement) across tasks and subjects. Furthermore, by varying the threshold used for determining laterality, the ability of functional magnetic resonance imaging (fMRI) to predict HLD was influenced for the AM method, whereas the LI method was relatively unaffected by changing the threshold. Using the LI method, the SA task was the most accurate for quantifying HLD (100% agreement with gold standard methods) with respect to the other three language tasks (80% accuracy for WSC, 65% for the LNL and 63% for phonological task). Depending on the method and the task, fMRI may be a promising tool for assessing HLD in neurosurgical patients. (orig.)

  20. Spectrum of neurosurgical complications following medical tourism: challenges of patients without borders. (United States)

    Idowu, Emmanuel Olufemi; Adewole, Oladipo Adeboluji


    The cost of medical care and availability of resources (human and facilities) which differs from nation to nation are amongst others, factors driving medical tourism (MT) despite its potential drawbacks. The aim of the study was to analyse all patients that presented with neurosurgical complications following MT. A single institution prospective study was carried out. Data which included patients' demographics, diagnosis, Glasgow coma scale score at admission, type of complication, and outcome were collected over a 3 year period and analysed. A total of 23 neurosurgical cases were seen during the study period with a median age of 42 years (17-70 years). India is the most common country visited by Nigerian patients. Nine patients died from various complications on arrival in Nigeria. There was no significant statistical difference between the outcome and patients clinical status prior to travel (p=0.107), country where the surgery was done (p=0.776), admission GCS in Nigeria (p=0.169), and redo surgery in Nigeria (0.181). Government in different nations should have legislations to ensure that medical tourists' receive appropriate care abroad, proper follow-up care upon their return, and also promulgate laws to regulate quasi and organised MT agencies that are operating in a regulatory vacuum.

  1. Evaluating functional MRI procedures for assessing hemispheric language dominance in neurosurgical patients

    Energy Technology Data Exchange (ETDEWEB)

    Baciu, M.V. [Pierre Mendes-France University, Laboratory of Psychology and Neurocognition, Grenoble (France); Watson, J.M.; Maccotta, L.; McDermott, K.B. [Washington University, Department of Psychology, St. Louis (United States); Buckner, R.L. [Washington University, Department of Psychology, St. Louis (United States); Howard Hughes Medical Institute, Washington University, St. Louis (United States); Gilliam, F.G. [Washington University School of Medicine, Department of Neurology, St. Louis (United States); Ojemann, J.G. [Washington University School of Medicine, Department of Neurological Surgery, St. Louis (United States)


    Two methods of quantifying hemispheric language dominance (HLD) in neurosurgical patients are compared: (1) an average magnitudes (AM) method, which is a calculation of the average signal intensity variation in regions of interest for each patient that were predefined in a group analysis for each task, and (2) a lateralization indices (LI) method, which is based on the number of activated pixels in regions of interest predefined in each individual patient. Four language tasks [a living/nonliving (LNL) judgment, word stem completion (WSC), semantic associate (SA) and a phonological associate (PA) task] were compared with ''gold standard'' measures such as the Wada test or electrocortical stimulation. Results showed that the LI method was more accurate (73% agreement with gold standard methods) than the AM method (only 40% agreement) across tasks and subjects. Furthermore, by varying the threshold used for determining laterality, the ability of functional magnetic resonance imaging (fMRI) to predict HLD was influenced for the AM method, whereas the LI method was relatively unaffected by changing the threshold. Using the LI method, the SA task was the most accurate for quantifying HLD (100% agreement with gold standard methods) with respect to the other three language tasks (80% accuracy for WSC, 65% for the LNL and 63% for phonological task). Depending on the method and the task, fMRI may be a promising tool for assessing HLD in neurosurgical patients. (orig.)

  2. Analysis of disruptive events and precarious situations caused by interaction with neurosurgical microscope. (United States)

    Eivazi, Shahram; Afkari, Hoorieh; Bednarik, Roman; Leinonen, Ville; Tukiainen, Markku; Jääskeläinen, Juha E


    Developments in micro-neurosurgical microscopes have improved operating precision and ensured the quality of outcomes. Using the stereoscopic magnified view, however, necessitates frequent manual adjustments to the microscope during an operation. This article reports on an investigation of the interaction details concerning a state-of-the-art micro-neurosurgical microscope. The video data from detailed observations of neurosurgeons' interaction patterns with the microscope were analysed to examine disruptive events caused by adjusting the microscope. The primary findings show that interruptions caused by adjusting the microscope handgrips and mouth switch prolong the surgery time up to 10%. Surgeons, we observed, avoid interaction with the microscope's controls, settings, and configurations by working at the edge of the view, operating on a non-focused view, and assuming unergonomic body postures. The lack of an automatic method for adjusting the microscope is a major problem that causes interruptions during micro-neurosurgery. From this understanding of disruptive events, we discuss the opportunities and limitations of interactive technologies that aim to reduce the frequency or shorten the duration of interruptions caused by microscope adjustment.

  3. Neurosurgical considerations after bull goring during festivities in Spain and Latin America. (United States)

    Spiotta, Alejandro M; Matoses, Salvador Martorell


    Bullfighting is a highly popular activity during festivities in Spain and Latin America. A scientific society for bullfight injuries, Congreso Internacional de Cirugía Taurina, was founded on November 24, 1974, in recognition of the distinctive pattern of injury that results from bull goring, and a subspecialty of general surgical trauma with emphasis on the acute surgical management of bull-goring injuries has emerged. Injuries to the head and neck are less frequent than genitourinary, inguinal, and abdominal injuries, but are more severe and more likely to result in death. This report reviews the primary venues in which bull goring and associated injuries occur, including the bullfight and the running of the bulls. The biomechanics of the primary and secondary goring injuries are reviewed, with an emphasis on those with the potential to result in neurosurgical injuries. This results in a very unique and devastating pattern of injury that combines penetrating and blunt mechanisms and results in polytrauma. Neurosurgical expertise should be immediately available on-site in the event of a life-threatening neurological injury.

  4. Effect of Geopolitical Forces on Neurosurgical Training in Sub-Saharan Africa. (United States)

    Dempsey, Kara E; Qureshi, Mahmood M; Ondoma, Solomon M; Dempsey, Robert J


    The population of Sub-Saharan Africa suffers from a critical shortage and maldistribution of health care professionals, especially highlighted in surgical subspecialties, such as neurosurgery. In light of The Lancet report and the World Health Organization's directive to provide essential surgical care through the developing world, solutions need to be found to close this training and distribution gap. Methods correcting the situation will only succeed if one understands the geopolitical forces which have shaped the distribution of health care in the region and continue to this day. Solutions have evolved from service to service with education. The partnering organizations, the Foundation of International Education in Neurological Surgery and the World Federation of Neurosurgical Societies, have supported neurosurgical training in the developing world, including curriculum, equipment, facilities, certification, and local acceptance, with a goal of developing a self-sustaining program within the developing country. These ideas heavily rely on partnerships to address classic geopolitical forces, including geography, drought, warfare, ethnic tensions, poverty, and lack of training facilities. Each can be addressed through partnerships, such as development of dyads with programs in developed countries and ongoing programs owned by the countries in question, but partnered with multiple international societies, institutions, and universities. This paper provides both a historic and topical overview of the forces at work which need to be addressed for success in delivering specialized care. This must always result in a self-sustaining program operated by the people of the home country with worldwide support through philanthropy and partnerships. Published by Elsevier Inc.

  5. Stereoscopic Three-Dimensional Neuroanatomy Lectures Enhance Neurosurgical Training: Prospective Comparison with Traditional Teaching. (United States)

    Clark, Anna D; Guilfoyle, Mathew R; Candy, Nicholas G; Budohoski, Karol P; Hofmann, Riikka; Barone, Damiano G; Santarius, Thomas; Kirollos, Ramez W; Trivedi, Rikin A


    Stereoscopic three-dimensional (3D) imaging is increasingly used in the teaching of neuroanatomy and although this is mainly aimed at undergraduate medical students, it has enormous potential for enhancing the training of neurosurgeons. This study aims to assess whether 3D lecturing is an effective method of enhancing the knowledge and confidence of neurosurgeons and how it compares with traditional two-dimensional (2D) lecturing and cadaveric training. Three separate teaching sessions for neurosurgical trainees were organized: 1) 2D course (2D lecture + cadaveric session), 2) 3D lecture alone, and 3) 3D course (3D lecture + cadaveric session). Before and after each session, delegates were asked to complete questionnaires containing questions relating to surgical experience, anatomic knowledge, confidence in performing procedures, and perceived value of 3D, 2D, and cadaveric teaching. Although both 2D and 3D lectures and courses were similarly effective at improving self-rated knowledge and understanding, the 3D lecture and course were associated with significantly greater gains in confidence reported by the delegates for performing a subfrontal approach and sylvian fissure dissection. Stereoscopic 3D lectures provide neurosurgical trainees with greater confidence for performing standard operative approaches and enhances the benefit of subsequent practical experience in developing technical skills in cadaveric dissection. Copyright © 2017. Published by Elsevier Inc.

  6. An Instrumented Glove to Assess Manual Dexterity in Simulation-Based Neurosurgical Education

    Directory of Open Access Journals (Sweden)

    Juan Diego Lemos


    Full Text Available The traditional neurosurgical apprenticeship scheme includes the assessment of trainee’s manual skills carried out by experienced surgeons. However, the introduction of surgical simulation technology presents a new paradigm where residents can refine surgical techniques on a simulator before putting them into practice in real patients. Unfortunately, in this new scheme, an experienced surgeon will not always be available to evaluate trainee’s performance. For this reason, it is necessary to develop automatic mechanisms to estimate metrics for assessing manual dexterity in a quantitative way. Authors have proposed some hardware-software approaches to evaluate manual dexterity on surgical simulators. This paper presents IGlove, a wearable device that uses inertial sensors embedded on an elastic glove to capture hand movements. Metrics to assess manual dexterity are estimated from sensors signals using data processing and information analysis algorithms. It has been designed to be used with a neurosurgical simulator called Daubara NS Trainer, but can be easily adapted to another benchtop- and manikin-based medical simulators. The system was tested with a sample of 14 volunteers who performed a test that was designed to simultaneously evaluate their fine motor skills and the IGlove’s functionalities. Metrics obtained by each of the participants are presented as results in this work; it is also shown how these metrics are used to automatically evaluate the level of manual dexterity of each volunteer.

  7. Intellectual Model-Based Configuration Management Conception

    Directory of Open Access Journals (Sweden)

    Bartusevics Arturs


    Full Text Available Software configuration management is one of the most important disciplines within the software development project, which helps control the software evolution process and allows including into the end project only tested and validated changes. To achieve this, software management completes certain tasks. Concrete tools are used for technical implementation of tasks, such as version control systems, servers of continuous integration, compilers, etc. A correct configuration management process usually requires several tools, which mutually exchange information by generating various kinds of transfers. When it comes to introducing the configuration management process, often there are situations when tool installation is started, yet at that given moment there is no general picture of the total process. The article offers a model-based configuration management concept, which foresees the development of an abstract model for the configuration management process that later is transformed to lower abstraction level models and tools are indicated to support the technical process. A solution of this kind allows a more rational introduction and configuration of tools

  8. International Subarachnoid Aneurysm Trial 2009 : Endovascular Coiling of Ruptured Intracranial Aneurysms Has No Significant Advantage Over Neurosurgical Clipping

    NARCIS (Netherlands)

    Bakker, Nicolaas A.; Metzemaekers, Jan D. M.; Groen, Rob J. M.; Mooij, Jan Jakob A.; Van Dijk, J. Marc C.

    In the May 2009 issue of The Lancet Neurology, the 5-year follow-up results of the International Subarachnoid Aneurysm Trial (ISAT) were published. The authors concluded that, although the significant difference between coiling and neurosurgical clipping of ruptured intracranial aneurysms in terms

  9. Model-based security engineering for the internet of things




    We propose in this chapter a Model-based Security Toolkit (SecKit) and methodology to address the control and protection of user data in the deployment of the Internet of Things (IoT). This toolkit takes a more general approach for security engineering including risk analysis, establishment of aspect-specific trust relationships, and enforceable security policies. We describe the integrated metamodels used in the toolkit and the accompanying security engineering methodology for IoT systems...

  10. Contemporary analysis of the intraoperative and perioperative complications of neurosurgical procedures performed in the sitting position. (United States)

    Himes, Benjamin T; Mallory, Grant W; Abcejo, Arnoley S; Pasternak, Jeffrey; Atkinson, John L D; Meyer, Fredric B; Marsh, W Richard; Link, Michael J; Clarke, Michelle J; Perkins, William; Van Gompel, Jamie J


    OBJECTIVE Historically, performing neurosurgery with the patient in the sitting position offered advantages such as improved visualization and gravity-assisted retraction. However, this position fell out of favor at many centers due to the perceived risk of venous air embolism (VAE) and other position-related complications. Some neurosurgical centers continue to perform sitting-position cases in select patients, often using modern monitoring techniques that may improve procedural safety. Therefore, this paper reports the risks associated with neurosurgical procedures performed in the sitting position in a modern series. METHODS The authors reviewed the anesthesia records for instances of clinically significant VAE and other complications for all neurosurgical procedures performed in the sitting position between January 1, 2000, and October 8, 2013. In addition, a prospectively maintained morbidity and mortality log of these procedures was reviewed for instances of subdural or intracerebral hemorrhage, tension pneumocephalus, and quadriplegia. Both overall and specific complication rates were calculated in relation to the specific type of procedure. RESULTS In a series of 1792 procedures, the overall complication rate related to the sitting position was 1.45%, which included clinically significant VAE, tension pneumocephalus, and subdural hemorrhage. The rate of any detected VAE was 4.7%, but the rate of VAE requiring clinical intervention was 1.06%. The risk of clinically significant VAE was highest in patients undergoing suboccipital craniotomy/craniectomy with a rate of 2.7% and an odds ratio (OR) of 2.8 relative to deep brain stimulator cases (95% confidence interval [CI] 1.2-70, p = 0.04). Sitting cervical spine cases had a comparatively lower complication rate of 0.7% and an OR of 0.28 as compared with all cranial procedures (95% CI 0.12-0.67, p < 0.01). Sitting cervical cases were further subdivided into extradural and intradural procedures. The rate of

  11. Working time of neurosurgical residents in Europe--results of a multinational survey. (United States)

    Stienen, Martin N; Netuka, David; Demetriades, Andreas K; Ringel, Florian; Gautschi, Oliver P; Gempt, Jens; Kuhlen, Dominique; Schaller, Karl


    The introduction of the European Working Time directive 2003/88/EC has led to a reduction of the working hours with distinct impact on the clinical and surgical activity of neurosurgical residents in training. A survey was performed among European neurosurgical residents between 06/2014 and 03/2015. Multiple logistic regression was used to assess the relationship between responder-specific variables (e.g., age, gender, country, postgraduate year (PGY)) and outcome (e.g., working time). A total of 652 responses were collected, of which n = 532 responses were taken into consideration. In total, 17.5, 22.1, 29.5, 19.5, 5.9, and 5.5 % of European residents indicated to work 80 h/week, respectively. Residents from France and Turkey (OR 4.72, 95 % CI 1.29-17.17, p = 0.019) and Germany (OR 2.06, 95 % CI 1.15-3.67, p = 0.014) were more likely to work >60 h/week than residents from other European countries. In total, 29 % of European residents were satisfied with their current working time, 11.3 % indicated to prefer reduced working time. More than half (55 %) would prefer to work more hours/week if this would improve their clinical education. Residents that rated their operative exposure as insufficient were 2.3 times as likely as others to be willing to work more hours (OR 2.32, 95 % CI 1.47-3.70, p 50 % of his/her working time in the operating room. By contrast, 77.4 % indicate to devote >25 % of their daily working time to administrative work. For every advanced PGY, the likelihood to spend >50 % of the working time in the OR increases by 19 % (OR 1.19, 95 % CI 1.02-1.40, p = 0.024) and the likelihood to spend >50 % of the working time with administrative work decreases by 18 % (OR 0.84, 95 % CI 0.76-0.94, p = 0.002). The results of this survey on >500 European neurosurgical residents clearly prove that less than 40 % conform with the 48-h week as claimed by the WTD2003/88/EC. Still, more than half of them would chose to work

  12. Correlation of hospital magnet status with the quality of physicians performing neurosurgical procedures in New York State. (United States)

    Bekelis, Kimon; Missios, Symeon; MacKenzie, Todd A


    The quality of physicians practicing in hospitals recognized for nursing excellence by the American Nurses Credentialing Center has not been studied before. We investigated whether Magnet hospital recognition is associated with higher quality of physicians performing neurosurgical procedures. We performed a cohort study of patients undergoing neurosurgical procedures from 2009-2013, who were registered in the New York Statewide Planning and Research Cooperative System (SPARCS) database. Propensity score adjusted multivariable regression models were used to adjust for known confounders, with mixed effects methods to control for clustering at the facility level. An instrumental variable analysis was used to control for unmeasured confounding and simulate the effect of a randomized trial. During the study period, 185,277 patients underwent neurosurgical procedures, and met the inclusion criteria. Of these, 66,607 (35.6%) were hospitalized in Magnet hospitals, and 118,670 (64.4%) in non-Magnet institutions. Instrumental variable analysis demonstrated that undergoing neurosurgical operations in Magnet hospitals was associated with a 13.6% higher chance of being treated by a physician with superior performance in terms of mortality (95% CI, 13.2% to 14.1%), and a 4.3% higher chance of being treated by a physician with superior performance in terms of length-of-stay (LOS) (95% CI, 3.8% to 4.7%) in comparison to non-Magnet institutions. The same associations were present in propensity score adjusted mixed effects models. Using a comprehensive all-payer cohort of neurosurgical patients in New York State we identified an association of Magnet hospital recognition with superior physician performance.

  13. Geographic proximity to specialized pediatric neurosurgical care in the contiguous United States. (United States)

    Ahmed, Abdul-Kareem; Duhaime, Ann-Christine; Smith, Timothy R


    OBJECTIVE Absent from an analysis of supply is consideration of the geographic distribution of pediatric neurosurgeons. Several patient socioeconomic metrics are known to be associated with outcome in pediatric neurosurgical diseases, such as hydrocephalus. The purpose of this study was to determine current geographic proximity to pediatric neurosurgical care using professional society databases. This study also sought to establish how socioeconomic factors are related to distance to care, using federal government-collected data. METHODS A list of currently practicing American Board of Pediatric Neurological Surgery (ABPNS)-certified neurosurgeons was compiled (ABPNS group). A separate list of practicing members of the Joint Pediatric Section (JPS) of the American Association of Neurological Surgeons/Congress of Neurological Surgeons was prepared (JPS group). Current primary practice locations were collected from each professional society database for each ABPNS or JPS neurosurgeon and were charted using ArcGIS mapping software (ESRI, version 10.3) on a United States Census Bureau map. The straight distance from the centroid of each zip code tabulation area (ZCTA) to the nearest neurosurgeon was determined by group type of neurosurgeon (ABPNS vs ABPNS + JPS). ZCTA-level data on demographic and socioeconomic factors were acquired from the American Community Survey, including data in children and young adults (0-18 or 0-24 years old) and the general population. These data were compared by distance to care and by groups of neurosurgeons (Pearson's chi-square analysis; the threshold of significance was set at 0.05). RESULTS Three hundred fifty-five practicing neurosurgeons providing pediatric care were located, of whom 215 surgeons were certified by the ABPNS and 140 were JPS members only. The analysis showed that 1 pediatric neurosurgeon is in practice for every 289,799 persons up to the age of 24 years. The average distance between a ZCTA and the nearest pediatric

  14. Supplementing the neurosurgical virtuoso: evolution of automation from mythology to operating room adjunct. (United States)

    Attenello, Frank J; Lee, Brian; Yu, Cheng; Liu, Charles Y; Apuzzo, Michael L J


    A central concept of scientific advancement in the medical and surgical fields is the incorporation of successful emerging ideas and technologies throughout the scope of human endeavors. The field of automation and robotics is a pivotal representation of this concept. Arising in the mythology of Homer, the concept of automation and robotics grew exponentially over the millennia to provide the substrate for a paradigm shift in the current and future practice of neurosurgery. We trace the growth of this field from the seminal concepts of Homer and Aristotle to early incorporation into neurosurgical practice. Resulting changes provide drastic and welcome advances in areas of visualization, haptics, acoustics, dexterity, tremor reduction, motion scaling, and surgical precision. Published by Elsevier Inc.

  15. The antigravity suit in neurosurgery. Cardiovascular responses in seated neurosurgical patients. (United States)

    Brodrick, P M; Ingram, G S


    The haemodynamic responses associated with inflation of the antigravity suit (G suit, aviation type) to 8.0 kPa were studied in a series of 40 patients who underwent neurosurgical operations in the sitting position. The study showed statistically significant increases in systolic arterial pressure (p less than 0.005) and mean central venous pressure (p less than 0.001) with inflation of the suit. The systolic arterial and mean central venous pressures remained significantly elevated immediately before deflation of the suit at the end of the operation (p less than 0.001 and p less than 0.005 respectively). The addition of 0.8-1.0 kPa positive end expiratory pressure during suit inflation was also investigated. A further increase in central venous pressure occurred but this did not achieve statistical significance.

  16. Algorithms for Design of Continuum Robots Using the Concentric Tubes Approach: A Neurosurgical Example. (United States)

    Anor, Tomer; Madsen, Joseph R; Dupont, Pierre


    We propose a novel systematic approach to optimizing the design of concentric tube robots for neurosurgical procedures. These procedures require that the robot approach specified target sites while navigating and operating within an anatomically constrained work space. The availability of preoperative imaging makes our approach particularly suited for neurosurgery, and we illustrate the method with the example of endoscopic choroid plexus ablation. A novel parameterization of the robot characteristics is used in conjunction with a global pattern search optimization method. The formulation returns the design of the least-complex robot capable of reaching single or multiple target points in a confined space with constrained optimization metrics. A particular advantage of this approach is that it identifies the need for either fixed-curvature versus variable-curvature sections. We demonstrate the performance of the method in four clinically relevant examples.

  17. Postural influence on intracranial and cerebral perfusion pressure in ambulatory neurosurgical patients

    DEFF Research Database (Denmark)

    Petersen, Lonnie Grove; Petersen, Johan Casper Grove; Andresen, Morten


    .4±4.2 mmHg when standing up (Phydrostatic pressure gradient with reference just below the heart, likely reflecting the venous hydrostatic...... indifference point. When upright, the decrease in ICP was attenuated, corresponding to formation of a separate hydrostatic gradient with reference to the base of the skull, likely reflecting the site of venous collapse. ICP therefore seems to be governed by pressure in the draining veins and collapse of neck......We evaluated postural effects on intracranial pressure (ICP) and cerebral perfusion pressure (CPP: mean arterial pressure (MAP) - ICP) in neurosurgical patients undergoing 24-hour ICP monitoring as part of their diagnostic workup. We identified 9 patients (5 women, age 44±20 yrs.; mean±SD) who were...

  18. Increased trends in the use of treatment-limiting decisions in a regional neurosurgical unit. (United States)

    Wilson, William T; McMillan, Tristan; Young, Adam M H; White, Mark A J


    Treatment-limiting decisions (TLDs) are employed to actively withhold treatment from patients whom clinicians feel would derive no benefit or suffer detrimental effects from further intervention. The use of such decisions has been heavily discussed in the media and clinicians in the past have been reluctant to institute them, even though it is in the best interests of the patients. Their use is influenced by several ethical, religious and social factors all of which have changed significantly over time. This study reports the trends in use of TLDs in a regional neurosurgical unit over 23 years. Patient archives were reviewed to identify the number of admissions and procedures performed at the Institute of Neurological Sciences, Glasgow, in the years 1988, 1997 and 2011. Death certificate records were used to identify mortality in the unit in the year 2011. Patient records were used to obtain details of diagnosis, time from admission to death, and the presence and timing of a TLD. The results show an increase in the use of TLDs, with decisions made for 89% of those who died in 2011, compared to 68% in 1997 and 51% in 1988. The number of admissions has increased substantially since 1988 as has the percentage of patients undergoing surgery (46, 67 and 72% in 1988, 1997 and 2011, respectively). There is a trending increase in the number of patients who have a TLD in our regional neurosurgical unit. This demonstrates an increased willingness of clinicians to recognise poor prognosis and to withdraw or withhold treatment in these cases. Continued appropriate use of the TLD is recommended but it is to only ever reflect the best interests of the patient.

  19. Feasibility and safety of GliaSite brachytherapy in treatment of CNS tumors following neurosurgical resection

    Directory of Open Access Journals (Sweden)

    Wernicke A


    Full Text Available Purpose: To investigate feasibility and safety of GliaSite brachytherapy for treatment of central nervous system (CNS tumors following neurosurgical resection. We report mature results of long-term follow-up, outcomes and toxicity. Materials and Methods: In the period from 2004 to 2007, 10 consecutive adult patients with recurrent, newly diagnosed, and metastatic brain malignancies underwent GliaSite brachytherapy following maximally safe neurosurgical resection. While 6/10 (60% patients were treated for recurrence, having previously been treated with external beam radiotherapy (EBRT, 4/10 (40% received radiotherapy (RT for the first time. A median dose of 52.0 Gy (range, 45.0 - 60.0 Gy was prescribed to 0.5 cm - 1.0 cm from the balloon surface. Radiation Therapy Oncology Group (RTOG criteria were used to assess toxicities associated with this technique. Follow-up was assessed with MRI scans and was available on all enrolled patients. Results: Median follow-up was 38 months (range, 18 - 57 months. Mean size of GliaSite balloon was 3.4 cm (range, 2.0 - 4.0 cm. Median survival was 14.0 months for the entire cohort after the treatment. The 17.6 and 16.0 months average survival for newly diagnosed and recurrent high grade gliomas (HGG, respectively, translated into a three-month improvement in survival in patients with newly diagnosed HGG compared to historical controls (P = 0.033. There were no RTOG grades 3 or 4 acute or late toxicities. Follow-up magnetic resonance imaging (MRI imaging did not identify radiation necrosis. Conclusions: Our data indicate that treatment with GliaSite brachytherapy is feasible, safe and renders acceptable local control, acute and long-term toxicities. We are embarking on testing larger numbers of patients with this treatment modality.

  20. Impact of clinical trials on neurosurgical practice: an assessment of case volume. (United States)

    Simon, Scott D; Koyama, Tatsuki; Zacharia, Brad E; Schirmer, Clemens M; Cheng, Joseph S


    To evaluate the effect of important trials on the practice of neurosurgery. We hypothesized that evidence from trials addressing the management of intracranial aneurysms (International Subarachnoid Aneurysm Trial [ISAT]) and nontraumatic intracerebral hemorrhages (Surgical Trial in Intracerebral Hemorrhage [STICH]) and vertebral augmentation for osteoporotic vertebral body fractures had a significant impact on the frequency of the corresponding neurosurgical procedures. A Medicare administrative database was queried for corresponding Common Procedural Terminology codes and units billed per calendar year. The effects of ISAT and STICH were evaluated using a generalized linear model. The effect of the vertebral augmentation study was evaluated using a t test. After publication of ISAT in 2002, the rate of increase in proportion of cerebral aneurysms that were treated with embolization (Common Procedural Terminology code 61624) per year increased from 3.9% to 5.5% (P = 0.01). After publication of STICH in 2005, the number of craniotomies performed for intracerebral hematoma decreased from 2341 in 2002 to 1646 in 2011 (P = 0.03). After 2 publications in 2009, performance of vertebral augmentation decreased from a high of 99,961 in 2009 per year to 77,108 in 2013 (P = 0.002). Randomized clinical trials remain the gold standard in the medical community to demonstrate efficacy, but their true impact relies on rapid and extensive assimilation into everyday medical practice. However, the described methodology establishes a temporal relationship only and does not prove causation. Nonetheless, trends in procedural volume suggest that the results of these select randomized clinical trials had a significant effect on neurosurgical practice affecting Medicare patients within an interval of a few years. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Sequential antimicrobial treatment with linezolid for neurosurgical infections: efficacy, safety and cost study. (United States)

    Martín-Gandul, Cecilia; Mayorga-Buiza, M J; Castillo-Ojeda, E; Gómez-Gómez, M J; Rivero-Garvía, M; Gil-Navarro, M V; Márquez-Rivas, F J; Jiménez-Mejías, M E


    Evidence for the effectiveness of linezolid in neurosurgical infections (NSIs) is growing. The comfortable oral dosage and tolerance of linezolid opens the possibility for sequential antimicrobial treatment (SAT) in stable patients after a period of intravenous treatment. To evaluate the efficacy and safety of SAT with oral linezolid in patients with NSI and to analyse the cost implications, an observational, non-comparative, prospective cohort study was conducted on clinically stable consecutive adult patients at the Neurosurgical Service. Following intravenous treatment, patients were discharged with SAT with oral linezolid. A total of 77 patients were included. The most common NSIs were: 41 surgical wound infections, 20 subdural empyemas, 18 epidural abscesses, and 16 brain abscesses. Forty-four percent of patients presented two or more concomitant NSIs. Aetiological agents commonly isolated were: Propionibacterium acnes (36 %), Staphylococcus aureus (23 %), Staphylococcus epidermidis (21 %) and Streptococcus spp. (13 %). The median duration of the SAT was 15 days (range, 3-42). The SAT was interrupted in five cases due to adverse events. The remainder of the patients were cured at the end of the SAT. A total of 1,163 days of hospitalisation were saved. An overall cost reduction of €516,188 was attributed to the SAT. Eight patients with device infections did not require removal of the device, with an additional cost reduction of €190,595. The mean cost saving per patient was €9,179. SAT with linezolid was safe and effective for the treatment of NSI. SAT reduces hospitalisation times, which means significant savings of health and economic resources.

  2. The use of simulation in neurosurgical education and training. A systematic review. (United States)

    Kirkman, Matthew A; Ahmed, Maria; Albert, Angelique F; Wilson, Mark H; Nandi, Dipankar; Sevdalis, Nick


    There is increasing evidence that simulation provides high-quality, time-effective training in an era of resident duty-hour restrictions. Simulation may also permit trainees to acquire key skills in a safe environment, important in a specialty such as neurosurgery, where technical error can result in devastating consequences. The authors systematically reviewed the application of simulation within neurosurgical training and explored the state of the art in simulation within this specialty. To their knowledge this is the first systematic review published on this topic to date. The authors searched the Ovid MEDLINE, Embase, and PsycINFO databases and identified 4101 articles; 195 abstracts were screened by 2 authors for inclusion. The authors reviewed data on study population, study design and setting, outcome measures, key findings, and limitations. Twenty-eight articles formed the basis of this systematic review. Several different simulators are at the neurosurgeon's disposal, including those for ventriculostomy, neuroendoscopic procedures, and spinal surgery, with evidence for improved performance in a range of procedures. Feedback from participants has generally been favorable. However, study quality was found to be poor overall, with many studies hampered by nonrandomized design, presenting normal rather than abnormal anatomy, lack of control groups and long-term follow-up, poor study reporting, lack of evidence of improved simulator performance translating into clinical benefit, and poor reliability and validity evidence. The mean Medical Education Research Study Quality Instrument score of included studies was 9.21 ± 1.95 (± SD) out of a possible score of 18. The authors demonstrate qualitative and quantitative benefits of a range of neurosurgical simulators but find significant shortfalls in methodology and design. Future studies should seek to improve study design and reporting, and provide long-term follow-up data on simulated and ideally patient outcomes.

  3. Mars 2020 Model Based Systems Engineering Pilot (United States)

    Dukes, Alexandra Marie


    The pilot study is led by the Integration Engineering group in NASA's Launch Services Program (LSP). The Integration Engineering (IE) group is responsible for managing the interfaces between the spacecraft and launch vehicle. This pilot investigates the utility of Model-Based Systems Engineering (MBSE) with respect to managing and verifying interface requirements. The main objectives of the pilot are to model several key aspects of the Mars 2020 integrated operations and interface requirements based on the design and verification artifacts from Mars Science Laboratory (MSL) and to demonstrate how MBSE could be used by LSP to gain further insight on the interface between the spacecraft and launch vehicle as well as to enhance how LSP manages the launch service. The method used to accomplish this pilot started through familiarization of SysML, MagicDraw, and the Mars 2020 and MSL systems through books, tutorials, and NASA documentation. MSL was chosen as the focus of the model since its processes and verifications translate easily to the Mars 2020 mission. The study was further focused by modeling specialized systems and processes within MSL in order to demonstrate the utility of MBSE for the rest of the mission. The systems chosen were the In-Flight Disconnect (IFD) system and the Mass Properties process. The IFD was chosen as a system of focus since it is an interface between the spacecraft and launch vehicle which can demonstrate the usefulness of MBSE from a system perspective. The Mass Properties process was chosen as a process of focus since the verifications for mass properties occur throughout the lifecycle and can demonstrate the usefulness of MBSE from a multi-discipline perspective. Several iterations of both perspectives have been modeled and evaluated. While the pilot study will continue for another 2 weeks, pros and cons of using MBSE for LSP IE have been identified. A pro of using MBSE includes an integrated view of the disciplines, requirements, and

  4. Methods and algorithms for model-based integration and testing

    NARCIS (Netherlands)

    Boumen, R.; Braspenning, N.C.W.M.; Jong, de I.S.M.; Mortel - Fronczak, van de J.M.; Rooda, J.E.


    This paper describes three Ph.D. projects performed in the framework of the Tangram project [1], in which the Systems Engineering group (Dept. of Mechanical Engineering) from the Eindhoven University of Technology is involved. The Tangram project is a close cooperation between the Embedded Systems

  5. An Integrated Model-Based Distributed Diagnosis and Prognosis Framework (United States)

    National Aeronautics and Space Administration — Diagnosis and prognosis are necessary tasks for system reconfiguration and fault-adaptive control in complex systems. Diagnosis consists of detec- tion, isolation...

  6. An Integrated Model-Based Diagnostic and Prognostic Framework (United States)

    National Aeronautics and Space Administration — Systems health monitoring is essential in guar- anteeing the safe, efficient, and correct opera- tion of complex engineered systems. Diagnosis, which consists of...

  7. Applying Model Based Systems Engineering to NASA's Space Communications Networks (United States)

    Bhasin, Kul; Barnes, Patrick; Reinert, Jessica; Golden, Bert


    System engineering practices for complex systems and networks now require that requirement, architecture, and concept of operations product development teams, simultaneously harmonize their activities to provide timely, useful and cost-effective products. When dealing with complex systems of systems, traditional systems engineering methodology quickly falls short of achieving project objectives. This approach is encumbered by the use of a number of disparate hardware and software tools, spreadsheets and documents to grasp the concept of the network design and operation. In case of NASA's space communication networks, since the networks are geographically distributed, and so are its subject matter experts, the team is challenged to create a common language and tools to produce its products. Using Model Based Systems Engineering methods and tools allows for a unified representation of the system in a model that enables a highly related level of detail. To date, Program System Engineering (PSE) team has been able to model each network from their top-level operational activities and system functions down to the atomic level through relational modeling decomposition. These models allow for a better understanding of the relationships between NASA's stakeholders, internal organizations, and impacts to all related entities due to integration and sustainment of existing systems. Understanding the existing systems is essential to accurate and detailed study of integration options being considered. In this paper, we identify the challenges the PSE team faced in its quest to unify complex legacy space communications networks and their operational processes. We describe the initial approaches undertaken and the evolution toward model based system engineering applied to produce Space Communication and Navigation (SCaN) PSE products. We will demonstrate the practice of Model Based System Engineering applied to integrating space communication networks and the summary of its

  8. Development of a robust model-based reactivity control system

    International Nuclear Information System (INIS)

    Rovere, L.A.; Otaduy, P.J.; Brittain, C.R.


    This paper describes the development and implementation of a digital model-based reactivity control system that incorporates a knowledge of the plant physics into the control algorithm to improve system performance. This controller is composed of a model-based module and modified proportional-integral-derivative (PID) module. The model-based module has an estimation component to synthesize unmeasurable process variables that are necessary for the control action computation. These estimated variables, besides being used within the control algorithm, will be used for diagnostic purposes by a supervisory control system under development. The PID module compensates for inaccuracies in model coefficients by supplementing the model-based output with a correction term that eliminates any demand tracking or steady state errors. This control algorithm has been applied to develop controllers for a simulation of liquid metal reactors in a multimodular plant. It has shown its capability to track demands in neutron power much more accurately than conventional controllers, reducing overshoots to almost negligible value while providing a good degree of robustness to unmodeled dynamics. 10 refs., 4 figs

  9. 'Integration'

    DEFF Research Database (Denmark)

    Olwig, Karen Fog


    , while the countries have adopted disparate policies and ideologies, differences in the actual treatment and attitudes towards immigrants and refugees in everyday life are less clear, due to parallel integration programmes based on strong similarities in the welfare systems and in cultural notions...... of equality in the three societies. Finally, it shows that family relations play a central role in immigrants’ and refugees’ establishment of a new life in the receiving societies, even though the welfare society takes on many of the social and economic functions of the family....

  10. Use of neurosurgical decision-making and damage-control neurosurgery courses in the Iraq and Afghanistan conflicts: a surgeon's experience. (United States)

    Teff, Richard J


    A shortage of Coalition neurological surgeons in the Iraq conflict prompted a creative approach to standardized neurosurgical care in 2007. After formulation of theater-wide clinical pathway guidelines, a need for standardized triage and neurological resuscitation was identified. The object was to establish a simple, reproducible course for medics, forward surgical and emergency room personnel, and other critical care providers to quickly standardize the ability of all deployed health care personnel to provide state-of-the-art neurosurgical triage and damage-control interventions. The methods applied were Microsoft PowerPoint presentations and hands-on learning. The year-long project resulted in more than 100 individuals being trained in neurosurgical decision making and in more than 15 surgeons being trained in damage-control neurosurgery. At the year's conclusion, hundreds of individuals received exceptional neurosurgical care from nonneurosurgical providers and a legacy course was left for future deployed providers to receive ongoing education at their own pace.

  11. Model based methods and tools for process systems engineering

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    need to be integrated with work-flows and data-flows for specific product-process synthesis-design problems within a computer-aided framework. The framework therefore should be able to manage knowledge-data, models and the associated methods and tools needed by specific synthesis-design work...... of model based methods and tools within a computer aided framework for product-process synthesis-design will be highlighted.......Process systems engineering (PSE) provides means to solve a wide range of problems in a systematic and efficient manner. This presentation will give a perspective on model based methods and tools needed to solve a wide range of problems in product-process synthesis-design. These methods and tools...

  12. Impact of Operating Room Environment on Postoperative Central Nervous System Infection in a Resource-Limited Neurosurgical Center in South Asia. (United States)

    Chidambaram, Swathi; Vasudevan, Madabushi Chakravarthy; Nair, Mani Nathan; Joyce, Cara; Germanwala, Anand V


    Postoperative central nervous system infections (PCNSIs) are serious complications following neurosurgical intervention. We previously investigated the incidence and causative pathogens of PCNSIs at a resource-limited, neurosurgical center in south Asia. This follow-up study was conducted to analyze differences in PCNSIs at the same institution following only one apparent change: the operating room air filtration system. This was a retrospective study of all neurosurgical cases performed between December 1, 2013, and March 31, 2016 at our center. Providers, patient demographic data, case types, perioperative care, rate of PCNSI, and rates of other complications were reviewed. These results were then compared with the findings of our previous study of neurosurgical cases between June 1, 2012, and June 30, 2013. All 623 neurosurgical operative cases over the study period were reviewed. Four patients (0.6%) had a PCNSI, and no patients had a positive cerebrospinal fluid (CSF) culture. In the previous study, among 363 cases, 71 patients (19.6%) had a PCNSI and 7 (1.9%) had a positive CSF culture (all Gram-negative organisms). The differences in both parameters are statistically significant (P system inside the neurosurgical operating rooms; this environmental change occurred during the 5 months between the 2 studies. This study demonstrates the impact of environmental factors in reducing infections. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Clinical indications for high-field 1.5 T intraoperative magnetic resonance imaging and neuro-navigation for neurosurgical procedures. Review of initial 100 cases

    International Nuclear Information System (INIS)

    Maesawa, Satoshi; Nakahara, Norimoto; Watanabe, Tadashi; Fujii, Masazumi; Saito, Kiyoshi; Kajita, Yasukazu; Nagatani, Tetsuya; Wakabayashi, Toshihiko; Yoshida, Jun


    Initial experiences are reviewed in an integrated operation theater equipped with an intraoperative high-field (1.5 T) magnetic resonance (MR) imager and neuro-navigation (BrainSUITE), to evaluate the indications and limitations. One hundred consecutive cases were treated, consisting of 38 gliomas, 49 other tumors, 11 cerebrovascular diseases, and 2 functional diseases. The feasibility and usefulness of the integrated theater were evaluated for individual diseases, focusing on whether intraoperative images (including diffusion tensor imaging) affected the surgical strategy. The extent of resection and outcomes in each histological category of brain tumors were examined. Intraoperative high-field MR imaging frequently affected or modified the surgical strategy in the glioma group (27/38 cases, 71.1%), but less in the other tumor group (13/49 cases, 26.5%). The surgical strategy was not modified in cerebrovascular or functional diseases, but the success of procedures and the absence of complications could be confirmed. In glioma surgery, subtotal or greater resection was achieved in 22 of the 31 patients (71%) excluding biopsies, and intraoperative images revealed tumor remnants resulting in the extension of resection in 21 of the 22 patients (95.4%), the highest rate of extension among all types of pathologies. The integrated neuro-navigation improved workflow. The best indication for intraoperative high-field MR imaging and integrated neuro-navigation is brain tumors, especially gliomas, and is supplementary in assuring quality in surgery for cerebrovascular or functional diseases. Immediate quality assurance is provided in several types of neurosurgical procedures. (author)

  14. Is the omega sign a reliable landmark for the neurosurgical team? An anatomical study about the central sulcus region

    Directory of Open Access Journals (Sweden)

    Thiago Rodrigues


    Full Text Available ABSTRACTThe central sulcus region is an eloquent area situated between the frontal and parietal lobes. During neurosurgical procedures, it is sometimes difficult to understand the cortical anatomy of this region.Objective Find alternative ways to anatomically navigate in this region during neurosurgical procedures.Method We analyzed eighty two human hemispheres using a surgical microscope and completed a review of the literature about central sulcus region.Results In 68/82 hemispheres, the central sulcus did not reach the posterior ramus of the lateral sulcus. A knob on the second curve of the precentral gyrus was reliably identified in only 64/82 hemispheres.Conclusion The morphometric data presented in this article can be useful as supplementary method to identify the central sulcus region landmarks.

  15. Perceived benefits and barriers to a career in pediatric neurosurgery: a survey of neurosurgical residents. (United States)

    Dias, Mark S; Sussman, Jeffrey S; Durham, Susan; Iantosca, Mark R


    Research suggests that there may be a growing disparity between the supply of and demand for both pediatric specialists and neurosurgeons. Whether pediatric neurosurgeons are facing such a disparity is disputable, but interest in pediatric neurosurgery (PNS) has waxed and waned as evidenced by the number of applicants for PNS fellowships. The authors undertook a survey to analyze current neurosurgical residents' perceptions of both benefits and deterrents to a pediatric neurosurgical career. All residents and PNS fellows in the United States and Canada during the academic year 2008-2009 were invited to complete a Web-based survey that assessed 1) demographic and educational information about residents and their residency training, particularly as it related to training in PNS; 2) residents' exposure to mentoring opportunities from pediatric neurosurgical faculty and their plans for the future; and 3) residents' perceptions about how likely 40 various factors were to influence their decision about whether to pursue a PNS career. Four hundred ninety-six responses were obtained: 89% of the respondents were male, 63% were married, 75% were in at least their 3rd year of postgraduate training, 61% trained in a children's hospital and 29% in a children's "hospital within a hospital," and 72% were in programs having one or more dedicated PNS faculty members. The residencies of 56% of respondents offered 6-11 months of PNS training and nearly three-quarters of respondents had completed 2 months of PNS training. During medical school, 92% had been exposed to neurosurgery and 45% to PNS during a clinical rotation, but only 7% identified a PNS mentor. Nearly half (43%) are considering a PNS career, and of these, 61% are definitely or probably considering post-residency fellowship. On the other hand, 68% would prefer an enfolded fellowship during residency. Perceived strengths of PNS included working with children, developing lasting relationships, wider variety of operations

  16. Image fusion of MRI and fMRI with intraoperative MRI data: methods and clinical relevance for neurosurgical interventions; Fusion von MRT-, fMRT- und intraoperativen MRT-Daten. Methode und klinische Bedeutung am Beispiel neurochirurgischer Interventionen

    Energy Technology Data Exchange (ETDEWEB)

    Moche, M.; Busse, H.; Dannenberg, C.; Schulz, T.; Schmidt, F.; Kahn, T. [Universitaetsklinikum Leipzig (Germany). Klinik und Poliklinik fuer Diagnostische Radiologie; Schmitgen, A. [GMD Forschungszentrum Informationstechnik GmbH-FIT, Sankt Augustin (Germany); Trantakis, C.; Winkler, D. [Klinik und Poliklinik fuer Neurochirurgie, Universitaetsklinikum Leipzig (Germany)


    The aim of this work was to realize and clinically evaluate an image fusion platform for the integration of preoperative MRI and fMRI data into the intraoperative images of an interventional MRI system with a focus on neurosurgical procedures. A vertically open 0.5 T MRI scanner was equipped with a dedicated navigation system enabling the registration of additional imaging modalities (MRI, fMRI, CT) with the intraoperatively acquired data sets. These merged image data served as the basis for interventional planning and multimodal navigation. So far, the system has been used in 70 neurosurgical interventions (13 of which involved image data fusion - requiring 15 minutes extra time). The augmented navigation system is characterized by a higher frame rate and a higher image quality as compared to the system-integrated navigation based on continuously acquired (near) real time images. Patient movement and tissue shifts can be immediately detected by monitoring the morphological differences between both navigation scenes. The multimodal image fusion allowed a refined navigation planning especially for the resection of deeply seated brain lesions or pathologies close to eloquent areas. Augmented intraoperative orientation and instrument guidance improve the safety and accuracy of neurosurgical interventions. (orig.) [German] Ziel dieser Arbeit waren die Realisierung und klinische Bewertung einer Bildfusion praeoperativer MRT- und fMRT-Bilder mit intraoperativen Datensaetzen eines interventionellen MRT-Systems am Beispiel neurochirurgischer Eingriffe. Ein vertikal offenes 0,5-T-MRT-System wurde mit einem erweiterten Navigationssystem ausgestattet, welches eine Integration zusaetzlicher Bildinformationen (Hochfeld-MRT, fMRT, CT) in die intraoperativ akquirierten Datensaetze erlaubt. Diese fusionierten Bilddaten wurden zur Interventionsplanung und multimodalen Navigation verwendet. Bisher wurde das System bei insgesamt 70 neurochirurgischen Eingriffen eingesetzt, davon 13

  17. Care of Pediatric Neurosurgical Patients in Iraq in 2007: Clinical and Ethical Experience of a Field Hospital (United States)


    penetrating spine injury      •      bioethics Abbreviations used in this paper: EMDG = Expeditionary Medical Group; GCS = Glasgow Coma Scale; group of high-acuity patients capable of consuming significant medical resources in a deployed environment. This information has the potential to...impact medical planning, logistics, and policy. 25 256 Care of pediatric neurosurgical patients in Iraq in 2007: clinical and ethical experience of

  18. New Directions in 3D Medical Modeling: 3D-Printing Anatomy and Functions in Neurosurgical Planning


    Gargiulo, Paolo; ?rnad?ttir, ?ris; G?slason, Magn?s; Edmunds, Kyle; ?lafsson, Ingvar


    This paper illustrates the feasibility and utility of combining cranial anatomy and brain function on the same 3D-printed model, as evidenced by a neurosurgical planning case study of a 29-year-old female patient with a low-grade frontal-lobe glioma. We herein report the rapid prototyping methodology utilized in conjunction with surgical navigation to prepare and plan a complex neurosurgery. The method introduced here combines CT and MRI images with DTI tractography, while using various image...

  19. Risk-to-Benefit Ratio of Venous Thromboembolism Prophylaxis for Neurosurgical Procedures at a Quaternary Referral Center. (United States)

    Agarwal, Nitin; Zenonos, Georgios A; Agarwal, Prateek; Walch, Frank J; Roach, Eileen; Stokes, Sandra J; Friedlander, Robert M; Gerszten, Peter C


    Pharmacological prophylaxis for venous thromboembolism (VTE) in the neurosurgical population is still a matter of debate, as the risk-to-benefit ratio is not well defined. To further evaluate the risk-to-benefit ratio of VTE prophylaxis (VTEP) for all neurosurgical procedures. A prospective evaluation was performed after the initiation of a VTEP protocol for 11 436 patients undergoing neurosurgical procedures over 24 mo. Unless a bleeding complication was present, 5000 international units of subcutaneous heparin every 8 h was ordered on postoperative day (POD) 1 for spine, POD2 for cranial, and by POD4 for subdural, intracerebral, and epidural hematoma cases. Incidence of VTE and any subsequent bleeding complications were noted. A total of 70 VTEs (0.6% overall) were documented (28 deep vein thrombosis, 42 pulmonary embnolism). The highest rates of VTE were associated with deformity (6.7%); open cerebrovascular (6.5%); subdural, intracerebral, and epidural hematoma (3.2%); spinal trauma (2.4%); and craniotomy for tumor (1.6%) cases. Seven cases of deep vein thrombosis progressed to pulmonary embolisms, and 66 of 70 VTEs occurred while on pharmacological VTEP. Fifty-four bleeding complications occurred on or after POD2 following initiation of VTEP. These bleeding complications consisted of any new clinically or radiographically observed hemorrhages. Twenty-eight of the 54 delayed bleeding complications required operative intervention with 1 mortality. Forty-five patients were on anticoagulation when the initial bleeding event occurred. Overall, an estimated 0.5% incidence of delayed bleeding complications was noted with 99.4% of patients within the study cohort remaining VTE free. This VTEP protocol was determined to afford a good risk-to-benefit ratio for a wide variety of neurosurgical procedures.

  20. Impact of a Vascular Neurosurgery Simulation-Based Course on Cognitive Knowledge and Technical Skills in European Neurosurgical Trainees. (United States)

    Zammar, Samer G; El Tecle, Najib E; El Ahmadieh, Tarek Y; Adelson, P David; Veznedaroglu, Erol; Surdell, Daniel L; Harrop, James S; Benes, Vladimir; Rezai, Ali R; Resnick, Daniel K; Bendok, Bernard R


    To assess microsurgical and diagnostic cerebral angiography modules and their corresponding objective assessment scales as educational tools for European neurosurgical residents at the European Association of Neurosurgical Societies Resident Vascular Neurosurgery course, which was held in Prague, Czech Republic, on September 2013. Microsurgical skills and cerebral angiography are fundamental skills in vascular neurosurgery. There is a need to develop a simulation-based curriculum focusing on these skills for neurosurgical trainees worldwide. The course consisted of 2 modules: microanastomosis and diagnostic cerebral angiography. In addition to an initial screening survey, each module was divided into 3 components: 1) a before didactic cognitive knowledge and technical skills testing, 2) a didactic lecture, and 3) an after didactic cognitive knowledge and technical skills testing. We compared the trainees' cognitive and technical scores from the before and after testing phases. Wilcoxon sum rank test was used to test statistical significance. The knowledge test median scores increased from 63% and 68% to 80% and 88% (P technical proficiency. Copyright © 2015. Published by Elsevier Inc.

  1. The use of IV-tubing as a closed-suction drainage system during neurosurgical cases in Tanzania. (United States)

    Bonfield, Christopher M; Shabani, Hamisi K; Kanumba, Emmanuel S; Ellegala, Dilantha B; Nicholas, Joyce


    Commercial closed-suctions drainage systems are commonly used in the United States and many other countries for use in neurosurgical cases. However, in Tanzania and other developing nations with fewer resources, these are not available. This report explores another option for a closed-system drainage system utilizing inexpensive supplies found commonly in hospitals around the world. Sterile IV-tubing is cut, inserted into the wound, and brought out through an adjacent puncture incision. For suction, an empty plastic bottle can be attached to the tubing. The IV-tubing closed-suction drainage system was applied in both cranial and spinal neurosurgical procedures, including as subdural, subgaleal, epidural, and suprafacial drains. It maintained suction and was an adequate substitute when commercial drains are unavailable. This report illustrates how sterile IV-tubing can be adapted for use as a closed-drainage system. It utilizes inexpensive supplies commonly found in many hospitals throughout the world and can be applied to both cranial and spinal neurosurgical procedures.

  2. Traceability in Model-Based Testing

    Directory of Open Access Journals (Sweden)

    Mathew George


    Full Text Available The growing complexities of software and the demand for shorter time to market are two important challenges that face today’s IT industry. These challenges demand the increase of both productivity and quality of software. Model-based testing is a promising technique for meeting these challenges. Traceability modeling is a key issue and challenge in model-based testing. Relationships between the different models will help to navigate from one model to another, and trace back to the respective requirements and the design model when the test fails. In this paper, we present an approach for bridging the gaps between the different models in model-based testing. We propose relation definition markup language (RDML for defining the relationships between models.

  3. Model-based testing for embedded systems

    CERN Document Server

    Zander, Justyna; Mosterman, Pieter J


    What the experts have to say about Model-Based Testing for Embedded Systems: "This book is exactly what is needed at the exact right time in this fast-growing area. From its beginnings over 10 years ago of deriving tests from UML statecharts, model-based testing has matured into a topic with both breadth and depth. Testing embedded systems is a natural application of MBT, and this book hits the nail exactly on the head. Numerous topics are presented clearly, thoroughly, and concisely in this cutting-edge book. The authors are world-class leading experts in this area and teach us well-used

  4. Model-based internal wave processing

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J.V.; Chambers, D.H.


    A model-based approach is proposed to solve the oceanic internal wave signal processing problem that is based on state-space representations of the normal-mode vertical velocity and plane wave horizontal velocity propagation models. It is shown that these representations can be utilized to spatially propagate the modal (dept) vertical velocity functions given the basic parameters (wave numbers, Brunt-Vaisala frequency profile etc.) developed from the solution of the associated boundary value problem as well as the horizontal velocity components. Based on this framework, investigations are made of model-based solutions to the signal enhancement problem for internal waves.

  5. Model Based Control of Reefer Container Systems

    DEFF Research Database (Denmark)

    Sørensen, Kresten Kjær

    This thesis is concerned with the development of model based control for the Star Cool refrigerated container (reefer) with the objective of reducing energy consumption. This project has been carried out under the Danish Industrial PhD programme and has been financed by Lodam together with the Da......This thesis is concerned with the development of model based control for the Star Cool refrigerated container (reefer) with the objective of reducing energy consumption. This project has been carried out under the Danish Industrial PhD programme and has been financed by Lodam together...

  6. Multidrug-resistant Acinetobacter meningitis in neurosurgical patients with intraventricular catheters: assessment of different treatments. (United States)

    Rodríguez Guardado, A; Blanco, A; Asensi, V; Pérez, F; Rial, J C; Pintado, V; Bustillo, E; Lantero, M; Tenza, E; Alvarez, M; Maradona, J A; Cartón, J A


    The treatment of multidrug-resistant Acinetobacter baumannii meningitis is a serious therapeutic problem due to the limited penetration of antibiotics into the CSF. We describe the clinical features and the outcome of a group of patients with nosocomial neurosurgical meningitis treated with different therapeutic options. All patients with nosocomial post-surgical meningitis due to A. baumannii diagnosed between 1990 and 2004 were retrospectively reviewed. During the period of study, 51 cases of this nosocomial infection were identified. Twenty-seven patients were treated with intravenous (iv) monotherapy: carbapenems (21 cases), ampicillin/sulbactam (4 cases) and other antibiotics (2 cases). Four patients were treated with iv combination therapy. Nineteen patients were treated with iv and intrathecal regimens: colistin by both routes (8 cases), carbapenems plus iv and intrathecal (4 cases) or only intrathecal (5 cases) aminoglycosides, and others (2 cases). Seventeen patients died due to the infection. One patient died without treatment. The mean (SD) duration of therapy was 17.4 (8.3) days (range 3-44). Although no patients treated with colistin died, we did not observe statistically significant differences in the mortality among the groups with different treatments. Nosocomial Acinetobacter meningitis has a high mortality. Combined therapy with iv and intrathecal colistin is a useful and safe option in the treatment of nosocomial Acinetobacter meningitis.

  7. Standards for Endovascular Neurosurgical Training and Certification of the Society of Korean Endovascular Neurosurgeons 2013 (United States)

    Shin, Dong-Seong; Park, Sukh-Que; Kang, Hyun-Seung; Yoon, Seok-Mann; Cho, Jae-Hoon; Lim, Dong-Jun; Baik, Min-Woo; Kwon, O Ki


    The need for standard endovascular neurosurgical (ENS) training programs and certification in Korea cannot be overlooked due to the increasing number of ENS specialists and the expanding ENS field. The Society of Korean Endovascular Neurosurgeons (SKEN) Certification Committee has prepared training programs and certification since 2010, and the first certificates were issued in 2013. A task force team (TFT) was organized in August 2010 to develop training programs and certification. TFT members researched programs and systems in other countries to develop a program that best suited Korea. After 2 years, a rough draft of the ENS training and certification regulations were prepared, and the standard training program title was decided. The SKEN Certification Committee made an official announcement about the certification program in March 2013. The final certification regulations comprised three major parts: certified endovascular neurosurgeons (EN), certified ENS institutions, and certified ENS training institutions. Applications have been evaluated and the results were announced in June 2013 as follows: 126 members received EN certification and 55 hospitals became ENS-certified institutions. The SKEN has established standard ENS training programs together with a certification system, and it is expected that they will advance the field of ENS to enhance public health and safety in Korea. PMID:24851145

  8. Assessing neurosurgical non-technical skills: an exploratory study of a new behavioural marker system. (United States)

    Michinov, Estelle; Jamet, Eric; Dodeler, Virginie; Haegelen, Claire; Jannin, Pierre


    The management of non-technical skills is a major factor affecting teamwork quality and patient safety. This article presents a behavioural marker system for assessing neurosurgical non-technical skills (BMS-NNTS). We tested the BMS during deep brain stimulation surgery. We developed the BMS in three stages. First, we drew up a provisional assessment tool based on the literature and observation tools developed for other surgical specialties. We then analysed videos made in an operating room (OR) during deep brain stimulation operations in order to ensure there were no significant omissions from the skills list. Finally, we used five videos of operations to identify the behavioural markers of non-technical skills in verbal communications. Analyses of more than six hours of observations revealed 3515 behaviours from which we determined the neurosurgeon's non-technical skills behaviour pattern. The neurosurgeon frequently engaged in explicit coordination, situation awareness and leadership behaviours. In addition, the neurosurgeon's behaviours differed according to the stage of the operation and the OR staff members with whom she was communicating. Our behavioural marker system provides a structured approach to assessing non-technical skills in the field of neurosurgery. It can also be transferred to other surgical specialties and used in surgeon training curricula. © 2014 John Wiley & Sons, Ltd.

  9. Autologous fibrin sealant (Vivostat®) in the neurosurgical practice: Part I: Intracranial surgical procedure (United States)

    Graziano, Francesca; Certo, Francesco; Basile, Luigi; Maugeri, Rosario; Grasso, Giovanni; Meccio, Flavia; Ganau, Mario; Iacopino, Domenico G.


    Background: Hemorrhages, cerebrospinal fluid (CSF) fistula and infections are the most challenging postoperative complications in Neurosurgery. In this study, we report our preliminary results using a fully autologous fibrin sealant agent, the Vivostat® system, in achieving hemostasis and CSF leakage repair during cranio-cerebral procedures. Methods: From January 2012 to March 2014, 77 patients were studied prospectively and data were collected and analyzed. Autologous fibrin sealant, taken from patient's blood, was prepared with the Vivostat® system and applied on the resection bed or above the dura mater to achieve hemostasis and dural sealing. The surgical technique, time to bleeding control and associated complications were recorded. Results: A total of 79 neurosurgical procedures have been performed on 77 patients. In the majority of cases (98%) the same autologous fibrin glue provided rapid hemostasis and dural sealing. No patient developed allergic reactions or systemic complications in association with its application. There were no cases of cerebral hematoma, swelling, infection, or epileptic seizures after surgery whether in the immediate or in late period follow-up. Conclusions: In this preliminary study, the easy and direct application of autologous fibrin sealant agent helped in controlling cerebral bleeding and in providing prompt and efficient dural sealing with resolution of CSF leaks. Although the use of autologous fibrin glue seems to be safe, easy, and effective, further investigations are strongly recommended to quantify real advantages and potential limitations. PMID:25984391

  10. Implementing family communication pathway in neurosurgical patients in an intensive care unit. (United States)

    Kodali, Sashikanth; Stametz, Rebecca; Clarke, Deserae; Bengier, Amanda; Sun, Haiyan; Layon, A J; Darer, Jonathan


    Family-centered care provides family members with basic needs, which includes information, reassurance, and support. Though national guidelines exist, clinical adoption often lags behind in this area. The Geisinger Health System developed and implemented a program for reliable delivery of best practices related to family communication to patients and families admitted to the intensive care unit (ICU). Using a quasiexperimental study design and the 24-item Family Satisfaction in the Intensive Care Unit questionnaire (FSICU-24©) to determine family satisfaction, we measured the impact of a "family communication pathway" facilitated by tools built into the electronic health record on the family satisfaction of neurosurgical patients admitted to the ICU. There was no statistically significant difference noted in family satisfaction as determined by FSICU-24 scores, including the Care and Decision Making constructs between the pre- and post-intervention pilot population. The percentage of families reporting the occurrence of a family conference showed only minimal improvement, from 46.5% before to 52.5% following the intervention (p = 0.565). This was mirrored by low numbers of documented family conferences by providers, suggesting poor uptake despite buy-in, use of electronic checklists, and repeated attempts at education. This paper reviews the challenges to and implications for implementing national guidelines in the area of family communication in an ICU coupled with the principles of clinical reengineering.

  11. Management of advanced intracranial intradural juvenile nasopharyngeal angiofibroma: combined single-stage rhinosurgical and neurosurgical approach. (United States)

    Naraghi, Mohsen; Saberi, Hooshang; Mirmohseni, Atefeh Sadat; Nikdad, Mohammad Sadegh; Afarideh, Mohsen


    Although intracranial extension of juvenile nasopharyngeal angiofibroma (JNA) occurs commonly, intradural penetration is extremely rare. Management of such tumors is a challenging issue in skull-base surgery, necessitating their removal via combined approaches. In this work, we share our experience in management of extensive intradural JNA. In a university hospital-based setting of 2 tertiary care academic centers, retrospective chart of 6 male patients (5 between 15 and 19 years old) was reviewed. Patients presented chiefly with nasal obstruction, epistaxis, and proptosis. One of them was an aggressive recurrent tumor in a 32-year-old patient. All cases underwent combined transnasal, transmaxillary, and craniotomy approaches assisted by the use of image-guided endoscopic surgery, with craniotomy preceding the rhinosurgical approach in 3 cases. Adding a transcranial approach to the transnasal and transmaxillary endoscopic approaches provided 2-sided exposure and appreciated access to the huge intradural JNAs. One postoperative cerebrospinal fluid leak and 1 postoperative recurrence at the site of infratemporal fossa were treated successfully. Otherwise, the course was uneventful in the remaining cases. Management of intracranial intradural JNA requires a multidisciplinary approach of combined open and endoscopic-assisted rhinosurgery and neurosurgery, because of greater risk for complications during the dissection. Carotid rupture and brain damage remain 2 catastrophic complications that should always be kept in mind. A combined rhinosurgical and neurosurgical approach also has the advantage of very modest cosmetic complications. © 2015 ARS-AAOA, LLC.

  12. A comparative study of effect of sevoflurane on intubating conditions with rocuronium in neurosurgical patients. (United States)

    Mitra, Saikat; Purohit, Shobha; Bhatia, Sonali; Kalra, Poonam; Sharma, Satya Prakash


    Rocuronium may not always be the preferred relaxant for rapid sequence intubation. When 2% sevoflurane is used in conjunction with rocuronium, it may reduce the time required for achieving complete skeletal muscle relaxation with the intubating dose of rocuronium. This study was prospective, randomised, double-blind in nature and compared the effect of sevoflurane on intubation time and intubating conditions when used along with rocuronium. Thirty adult patients belonging to American Society of Anesthesiologists physical status Grades 1 and 2, of either gender aged between 30 and 65 years undergoing neurosurgical operations were randomly allocated into two equal groups: Group R received 0.8 mg/kg rocuronium, and Group RS received 0.8 mg/kg of rocuronium with 2% sevoflurane. Onset time of intubation was assessed using train-of-four stimuli. The intubating conditions were compared using the Cooper scoring system and the haemodynamic responses were compared between the two groups. The onset time of intubation was 101.73 ± 10.28 s in Group R and 60.4 ± 4.1 s in Group RS (P Rocuronium 0.8 mg/kg along with 2% sevoflurane provides excellent intubating conditions within 60-66 s from its administration.

  13. Neurosurgery certification in member societies of the World Federation of Neurosurgical Societies: Asia. (United States)

    Gasco, Jaime; Braun, Jonathan D; McCutcheon, Ian E; Black, Peter M


    To objectively compare the complexity and diversity of the certification process in neurological surgery in member societies of the World Federation of Neurosurgical Societies. This study centers in continental Asia. We provide here an analysis based on the responses provided to a 13-item survey. The data received were analyzed, and three Regional Complexity Scores (RCS) were designed. To compare national board experience, eligibility requirements for access to the certification process, and the obligatory nature of the examinations, an RCS-Organizational score was created (20 points maximum). To analyze the complexity of the examination, an RCS-Components score was designed (20 points maximum). The sum of both is presented in a Global RCS score. Only those countries that responded to the survey and presented nationwide homogeneity in the conduction of neurosurgery examinations could be included within the scoring system. In addition, a descriptive summary of the certification process per responding society is also provided. On the basis of the data provided by our RCS system, the highest global RCS was achieved by South Korea and Malaysia (21/40 points) followed by the joint examination of Singapore and Hong-Kong (FRCS-Ed) (20/40 points), Japan (17/40 points), the Philippines (15/40 points), and Taiwan (13 points). The experience from these leading countries should be of value to all countries within Asia. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. MANAGEMENT OF ENDOCRINE DISEASE: Neuroendocrine surveillance and management of neurosurgical patients. (United States)

    Garrahy, Aoife; Sherlock, Mark; Thompson, Christopher J


    Advances in the management of traumatic brain injury, subarachnoid haemorrhage and intracranial tumours have led to improved survival rates and an increased focus on quality of life of survivors. Endocrine sequelae of the acute brain insult and subsequent neurosurgery, peri-operative fluid administration and/or cranial irradiation are now well described. Unrecognised acute hypopituitarism, particularly ACTH/cortisol deficiency and diabetes insipidus, can be life threatening. Although hypopituitarism may be transient, up to 30% of survivors of TBI have chronic hypopituitarism, which can diminish quality of life and hamper rehabilitation. Patients who survive SAH may also develop hypopituitarism, though it is less common than after TBI. The growth hormone axis is most frequently affected. There is also accumulating evidence that survivors of intracranial malignancy, who have required cranial irradiation, may develop hypopituitarism. The time course of the development of hormone deficits is varied, and predictors of pituitary dysfunction are unreliable. Furthermore, diagnosis of GH and ACTH deficiency require dynamic testing that can be resource intensive. Thus the surveillance and management of neuroendocrine dysfunction in neurosurgical patients poses significant logistic challenges to endocrine services. However, diagnosis and management of pituitary dysfunction can be rewarding. Appropriate hormone replacement can improve quality of life, prevent complications such as muscle atrophy, infection and osteoporosis and improve engagement with physiotherapy and rehabilitation. © 2017 European Society of Endocrinology.

  15. Behavior Changes and Gait Unsteadiness: The Value of Imaging and Prompt Neurosurgical Intervention

    Directory of Open Access Journals (Sweden)

    Andreia Costa


    Full Text Available Cavernous angiomas are central nervous system malformations. Most common manifestations are seizures and acute focal neurological deficits. We present a case report of a seventy-one year-old man with a two-month history of behavior changes, attention deficit and indifference followed by gait unsteadiness. Neuropsychological evaluation showed severe cognitive impairment and executive dysfunction. Head computed tomography depicted a supraventricular hydrocephaly. Magnetic resonance imaging revealed a small hemorrhage, contiguous to a mesencephalic cavernous angioma, obstructing the Sylvius aqueduct, causing secondary hydrocephalus. Four months after endoscopic ventriculocisternostomy, neuropsychological evaluation showed improvement and the patient regained autonomy. Parenchyma cavernous angiomas causing direct hemorrhage and subsequent obstruction of the Sylvian aqueduct are uncommon. Sub-acute behavior and mental state abnormalities are rare first manifestations of cavernous angioma and requires high clinical suspicion for its correct diagnosis. Magnetic resonance imaging evaluation is crucial in the detection of such patients as prompt neurosurgical intervention may substantially improve cognitive function.

  16. Information exchange in global logistics chains : An application for model-based auditing,

    NARCIS (Netherlands)

    Veenstra, A.W.; Hulstijn, J.; Christiaanse, R.M.J.; Tan, Y.


    An integrated data pipeline has been proposed to meet requirements for visibility, supervision and control in global supply chains. How can data integration be used for risk assessment, monitoring and control in global supply chains? We argue that concepts from model-based auditing can be used to

  17. Information Exchange in Global Logistics Chains : An application for Model-based Auditing (abstract)

    NARCIS (Netherlands)

    Veenstra, A.W.; Hulstijn, J.; Christiaanse, R.; Tan, Y.


    An integrated data pipeline has been proposed to meet requirements for supply chain visibility and control. How can data integration be used for risk assessment, monitoring and control in global supply chains? We argue that concepts from model-based auditing can be used to model the ‘ideal’ flow of

  18. Service creation: a model-based approach

    NARCIS (Netherlands)

    Quartel, Dick; van Sinderen, Marten J.; Ferreira Pires, Luis


    This paper presents a model-based approach to support service creation. In this approach, services are assumed to be created from (available) software components. The creation process may involve multiple design steps in which the requested service is repeatedly decomposed into more detailed

  19. Model based development of engine control algorithms

    NARCIS (Netherlands)

    Dekker, H.J.; Sturm, W.L.


    Model based development of engine control systems has several advantages. The development time and costs are strongly reduced because much of the development and optimization work is carried out by simulating both engine and control system. After optimizing the control algorithm it can be executed

  20. An acoustical model based monitoring network

    NARCIS (Netherlands)

    Wessels, P.W.; Basten, T.G.H.; Eerden, F.J.M. van der


    In this paper the approach for an acoustical model based monitoring network is demonstrated. This network is capable of reconstructing a noise map, based on the combination of measured sound levels and an acoustic model of the area. By pre-calculating the sound attenuation within the network the

  1. Approximation Algorithms for Model-Based Diagnosis

    NARCIS (Netherlands)

    Feldman, A.B.


    Model-based diagnosis is an area of abductive inference that uses a system model, together with observations about system behavior, to isolate sets of faulty components (diagnoses) that explain the observed behavior, according to some minimality criterion. This thesis presents greedy approximation

  2. Probabilistic Model-based Background Subtraction

    DEFF Research Database (Denmark)

    Krüger, Volker; Anderson, Jakob; Prehn, Thomas


    is the correlation between pixels. In this paper we introduce a model-based background subtraction approach which facilitates prior knowledge of pixel correlations for clearer and better results. Model knowledge is being learned from good training video data, the data is stored for fast access in a hierarchical...

  3. Opinion dynamics model based on quantum formalism

    Energy Technology Data Exchange (ETDEWEB)

    Artawan, I. Nengah, E-mail: [Theoretical Physics Division, Department of Physics, Udayana University (Indonesia); Trisnawati, N. L. P., E-mail: [Biophysics, Department of Physics, Udayana University (Indonesia)


    Opinion dynamics model based on quantum formalism is proposed. The core of the quantum formalism is on the half spin dynamics system. In this research the implicit time evolution operators are derived. The analogy between the model with Deffuant dan Sznajd models is discussed.

  4. Model-based auditing using REA

    NARCIS (Netherlands)

    Weigand, H.; Elsas, P.


    The recent financial crisis has renewed interest in the value of the owner-ordered auditing tradition that starts from society's long-term interest rather than management interest. This tradition uses a model-based auditing approach in which control requirements are derived in a principled way. A

  5. Model-based testing for software safety

    NARCIS (Netherlands)

    Gurbuz, Havva Gulay; Tekinerdogan, Bedir


    Testing safety-critical systems is crucial since a failure or malfunction may result in death or serious injuries to people, equipment, or environment. An important challenge in testing is the derivation of test cases that can identify the potential faults. Model-based testing adopts models of a

  6. Springer handbook of model-based science

    CERN Document Server

    Bertolotti, Tommaso


    The handbook offers the first comprehensive reference guide to the interdisciplinary field of model-based reasoning. It highlights the role of models as mediators between theory and experimentation, and as educational devices, as well as their relevance in testing hypotheses and explanatory functions. The Springer Handbook merges philosophical, cognitive and epistemological perspectives on models with the more practical needs related to the application of this tool across various disciplines and practices. The result is a unique, reliable source of information that guides readers toward an understanding of different aspects of model-based science, such as the theoretical and cognitive nature of models, as well as their practical and logical aspects. The inferential role of models in hypothetical reasoning, abduction and creativity once they are constructed, adopted, and manipulated for different scientific and technological purposes is also discussed. Written by a group of internationally renowned experts in ...

  7. Model-based version management system framework

    International Nuclear Information System (INIS)

    Mehmood, W.


    In this paper we present a model-based version management system. Version Management System (VMS) a branch of software configuration management (SCM) aims to provide a controlling mechanism for evolution of software artifacts created during software development process. Controlling the evolution requires many activities to perform, such as, construction and creation of versions, identification of differences between versions, conflict detection and merging. Traditional VMS systems are file-based and consider software systems as a set of text files. File based VMS systems are not adequate for performing software configuration management activities such as, version control on software artifacts produced in earlier phases of the software life cycle. New challenges of model differencing, merge, and evolution control arise while using models as central artifact. The goal of this work is to present a generic framework model-based VMS which can be used to overcome the problem of tradition file-based VMS systems and provide model versioning services. (author)

  8. Clinical characteristics of post-neurosurgical Klebsiella pneumoniae meningitis in adults and a clinical comparison to the spontaneous form in a Taiwanese population. (United States)

    Chang, Wen-Neng; Lu, Chen-Hsien; Huang, Chi-Ren; Chuang, Yao-Chung; Tsai, Nai-Wen; Chang, Chiung-Chih; Chen, Shu-Fang; Wang, Hung-Chen; Yang, Tzu-Ming; Hsieh, Mei-Jen; Chien, Chun-Chih


    A total of 46 patients (nine post-neurosurgical, 37 spontaneous) with adult bacterial meningitis (ABM) caused by Klebsiellapneumoniae infection were included in this study. The nine patients in the post-neurosurgical K. pneumoniae ABM group (seven male, two female) had a mean age of 48.9 years. Two patients in this group also had diabetes mellitus (DM) and one had liver disease. The most common presentation of patients in post-neurosurgical K. pneumoniae ABM group was fever (nine patients), followed by altered consciousness (seven patients) and hydrocephalus (six patients). With medical and/or surgical treatment, a mortality of 22.2% (2/9) occurred. Compared to patients who had spontaneous K. pneumoniae ABM, those with the post-neurosurgical form had a lower incidence of community-acquired infection, seizure and DM, but had a higher incidence of leukocytosis, hydrocephalus, cerebrospinal fluid leak and bacterial strains with extended-spectrum beta-lactamase. Univariate analysis found these clinical differences to be statistically significant, however they were not significant on multivariate analysis. This study reveals that there are clinical differences between the post-neurosurgical and spontaneous presentations of K. pneumoniae ABM. Copyright 2009 Elsevier Ltd. All rights reserved.

  9. Efficacy of neurosurgery resident education in the new millennium: the 2008 Council of State Neurosurgical Societies post-residency survey results. (United States)

    Mazzola, Catherine A; Lobel, Darlene A; Krishnamurthy, Satish; Bloomgarden, Gary M; Benzil, Deborah L


    Neurosurgical residency training paradigms have changed in response to Accreditation Council for Graduate Medical Education mandates and demands for quality patient care. Little has been done to assess resident education from the perspective of readiness to practice. To assess the efficacy of resident training in preparing young neurosurgeons for practice. In response to Resolution V-2007F of the Council of State Neurosurgical Societies, a survey was developed for neurosurgeons who applied for oral examination, Part II of the American Board of Neurological Surgery boards, in 2002 through 2007 (N = 800). The survey was constructed in "survey monkey" format and sent to 775 of 800 (97%) neurosurgeons for whom e-mail addresses were available. The response rate was 30% (233/775). Most neurosurgeons were board certified (n = 226, 97%). General neurosurgical training was judged as adequate by a large majority (n = 188, 80%). Sixty-percent chose to pursue at least 1 additional year of fellowship training (n = 138, 60%). Surgical skills training was acceptable, but 6 skill-technique areas were reported to be inadequate (endovascular techniques, neurosurgical treatment of pain, stereotactic radiosurgery, epilepsy surgery, cranial base surgery, and stereotactic neurosurgery). Respondents also noted inadequate education in contract negotiation, practice evaluation, and management. The study suggests that neurosurgeons believed that they were well trained in their surgical skills except for some areas of subspecialization. However, there is a significant need for improvement of resident training in the areas of socioeconomic and medicolegal education. Continued evaluation of the efficacy of neurosurgical education is important.

  10. Neurosurgical intervention in patients with mild traumatic brain injury and its effect on neurological outcomes. (United States)

    Tierney, Kevin James; Nayak, Natasha V; Prestigiacomo, Charles J; Sifri, Ziad C


    The object of this study was to determine the mortality and neurological outcome of patients with mild traumatic brain injury (mTBI) who require neurosurgical intervention (NSI), identify clinical predictors of a poor outcome, and investigate the effect of failed nonoperative management and delayed NSI on outcome. A cross-sectional study of 10 years was performed, capturing all adults with mTBI and NSI. Primary outcome variables were mortality and Glasgow Outcome Scale (GOS) score. Patients were divided into an immediate intervention group, which received an NSI after the initial cranial CT scan, and a delayed intervention group, which had failed nonoperative management and received an NSI after 2 or more cranial CT scans. The mortality rate in mTBI patients requiring NSI was 13%, and the mean GOS score was 3.6 ± 1.2. An age > 60 years was independently predictive of a worse outcome, and epidural hematoma was independently predictive of a good outcome. Logistic regression analysis using independent variables was calculated to create a model for predicting poor neurological outcomes in patients with mTBI undergoing NSI and had 74.1% accuracy. Patients in the delayed intervention group had worse mortality (25% vs 9%) and worse mean GOS scores (2.9 ± 1.3 vs 3.7 ± 1.2) than those in the immediate intervention group. Data in this study demonstrate that patients with mTBI requiring NSI have higher mortality rates and worse neurological outcomes and should therefore be classified separately from mTBI patients not requiring NSI. Additionally, mTBI patients requiring NSI after the failure of nonoperative management have worse outcomes than those receiving immediate intervention and should be considered separately.

  11. Head Injury in the Elderly: What Are the Outcomes of Neurosurgical Care? (United States)

    Whitehouse, Kathrin Joanna; Jeyaretna, Deva Sanjeeva; Enki, Doyo Gragn; Whitfield, Peter C


    Epidemiologic studies show that an increasing proportion of those presenting with head trauma are elderly. This study details the outcomes of elderly patients with head trauma admitted to a regional United Kingdom neurosurgical unit. The notes and imaging were reviewed of all patients with head injury aged ≥75 years, admitted from 1 January 2007 to 31 December 2010, including mortality data up to at least 2 years after discharge. Outcomes comprised death as an inpatient, by 30 days and 1 year after discharge; Glasgow Outcome Score; discharge Glasgow Coma Scale (GCS) score; recurrence; readmission; reoperation; and complication. A total of 263 patients were admitted: 26 with acute subdural hematoma (ASDH); 175 with chronic subdural hematoma (CSDH); and 46 with mixed subdural collections (ACSDH). Sixteen patients had other head injury diagnoses. Patients with ASDH had a significantly lower survival rate than did those with CSDH or ACSDH: the odds of inpatient death for patients with ASDH was 15.38 (vs. those with CSDH). For all subdural hematomas (SDHs), low American Society of Anesthesiologists score was an independent predictor of early death. Death at 1 year was predicted by head injury severity measured by admission GCS score (P = 0.028), long anesthetic (P = 0.002), and the presence of bilateral SDH (P = 0.002). Unfavorable Glasgow Outcome Scale score (1-3) was predicted by age greater than 85 years (P = 0.029); larger depth of subdural (P neurosurgery after head injury have SDHs. Our results are better than many previously reported; however, the rate of death for those with ASDH is still high. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  12. Comparative study between sugammadex and neostigmine in neurosurgical anesthesia in pediatric patients

    Directory of Open Access Journals (Sweden)

    Ayman A Ghoneim


    Full Text Available Background: Postoperative recurarization remains a risk following the use of the conventional neuromuscular blocking agents. In addition, none of the commonly used reversal agents, such as neostigmine or edrophonium are capable of reliably reversing profound blockade. The present comparative and randomized study investigated the use of sugammadex for reversing profound neuromuscular blockade (NMB in pediatric neurosurgical patients undergone posterior fossa tumor excision. Patients and Methods: Forty pediatric patients undergoing elective craniotomy for posterior fossa tumor excision were randomly divided into either of neostigmine or sugammadex group in which muscle relaxant was reversed at the end of anesthesia either with neostigmine 0.04 mg/kg added to atropine 0.02 mg/kg or sugammadex 4 mg/kg alone, respectively. The primary endpoint was the time from the administration of sugammadex or neostigmine to recovery of the train of four (TOF ratio to 90% after rocuronium-induced neuromuscular block. Unpaired t-test was used to compare continuous variables between groups. Meanwhile, repeated ANOVA was used to detect intragroup differences. Results: Patients in sugammadex group attained a TOF ratio 90% in statistically shorter time (1.4 ± 1.2 min than those in neostigmine group (25.16 ± 6.49 min for reversal of the rocuronium. Mean arterial pressure and heart rate were significantly higher in neostigmine group at 2, 5 and 10 min after administration of the reversal agents and returned nonsignificantly different after that. With no recurarization in any patient throughout the study period. Conclusion: Sugammadex rapidly and effectively reverses rocuronium-induced NMB in pediatric patients undergoing neurosurgery when administered at reappearance of T2 of TOF at dose 4 mg/kg.

  13. Neurosurgical operating computerized tomographic scanner system. The CT scanner in the operating theater

    Energy Technology Data Exchange (ETDEWEB)

    Okudera, Hiroshi; Sugita, Kenichiro; Kobayashi, Shigeaki; Kimishima, Sakae; Yoshida, Hisashi


    A neurosurgical operating computerized tomography scanner system is presented. This system has been developed for obtaining intra- and postoperative CT images in the operating room. A TCT-300 scanner (manufactured by the Toshiba Co., Tokyo) is placed in the operating room. The realization of a true intraoperative CT image requires certain improvements in the CT scanner and operating table. To adjust the axis of the co-ordinates of the motor system of the MST-7000 microsurgical operating table (manufactured by the Mizuho Ika Co., Tokyo) to the CT scanner, we have designed an interface and a precise motor system so that the computer of the CT scanner can directly control the movement of the operating table. Furthermore, a new head-fixation system has been designed for producing artifact-free intraoperative CT images. The head-pins of the head-fixation system are made of carbon-fiber bars and titanium tips. A simulation study of the total system in the operating room with the CT scanner, operating table, and head holder using a skull model yielded a degree of error similar to that in the phantom testing of the original scanner. Three patients underwent resection of a glial tumor using this system. Intraoperative CT scans taken after dural opening showed a bulging of the cortex, a shift in the central structure, and a displacement of the cortical subarachnoid spaces under the influence of gravity. With a contrast medium the edge of the surrounding brain after resection was enhanced and the residual tumor mass was demonstrated clearly. This system makes it possible to obtain a noninvasive intraoperative image in a situation where structural shifts are taking place.

  14. Intrathecal or intraventricular therapy for post-neurosurgical Gram-negative meningitis: matched cohort study. (United States)

    Shofty, B; Neuberger, A; Naffaa, M E; Binawi, T; Babitch, T; Rappaport, Z H; Zaaroor, M; Sviri, G; Paul, M


    Gram-negative post-operative meningitis due to carbapenem-resistant bacteria (CR-GNPOM) is a dire complication of neurosurgical procedures. We performed a nested propensity-matched historical cohort study aimed at examining the possible benefit of intrathecal or intraventricular (IT/IV) antibiotic treatment for CR-GNPOM. We included consecutive adults with GNPOM in two centres between 2005 and 2014. Patients receiving combined systemic and IT/IV treatment were matched to patients receiving systemic treatment only. Matching was done based on the propensity of the patients to receive IT/IV treatment. We compared patient groups with 30-day mortality defined as the primary outcome. The cohort included 95 patients with GNPOM. Of them, 37 received IT/IV therapy in addition to systemic treatment (22 with colistin and 15 with amikacin), mostly as initial therapy, through indwelling cerebrospinal fluid drains. Variables associated with IT/IV therapy in the propensity score included no previous neurosurgery, time from admission to meningitis, presence of a urinary catheter and GNPOM caused by carbapenem-resistant Gram-negative bacteria. Following propensity matching, 23 patients given IT/IV therapy and 27 controls were analysed. Mortality was significantly lower with IT/IV therapy: 2/23 (8.7%) versus 9/27 (33.3%), propensity-adjusted OR 0.19, 95% CI 0.04-0.99. Death or neurological deterioration at 30 days, 14-day and in-hospital mortality were lower with IT/IV therapy (OR <0.4 for all) without statistically significant differences. Among patients discharged alive, those receiving IT/IV therapy did not experience more neurological deterioration. Serious adverse events with IT/IV therapy were not documented. Our results support the early use of IT antibiotic treatment for CR-GNPOM when a delivery method is available. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  15. Preventive effect of tamsulosin on postoperative urinary retention in neurosurgical patients. (United States)

    Basheer, Azam; Alsaidi, Mohammed; Schultz, Lonni; Chedid, Mokbel; Abdulhak, Muwaffak; Seyfried, Donald


    Postoperative urinary retention (POUR) is common in neurosurgical patients. The use of alpha-blockade therapy, such as tamsulosin, has benefited many patients with a history of obstructive uropathy by decreasing lower urinary tract symptoms such as distension, infections, and stricture formation, as well as the incidence of POUR. For this study, we targeted patients who had undergone spinal surgery to examine the prophylactic effects of tamsulosin. Increased understanding of this therapy will assist in minimizing the morbidity of spinal surgery. We enrolled 95 male patients undergoing spine surgery in a double-blind, randomized, placebo-controlled trial. Patients were randomly assigned to receive either preoperative tamsulosin (N = 49) or a placebo (N = 46) and then followed-up prospectively for the development of POUR after removal of an indwelling urinary catheter (IUC). They were also followed-up for the incidence of IUC reinsertions. The rate of developing POUR was similar in both the groups. Of the 49 patients given tamsulosin, 16 (36%) developed POUR compared to 13 (28%) from the control group ( P = 0.455). In the control group, 5 (11%) patients had IUC re-inserted postoperatively, whereas 7 (14%) patients in the tamsulosin group had IUC re-inserted postoperatively ( P = 0.616). In patients suffering from axial-type symptoms (i.e., mechanical back pain), 63% who received tamsulosin and 18% from the control group ( P = 0.048) developed POUR. Overall, there was no statistically significant difference in the rates of developing POUR among patients in either group. POUR is caused by a variety of factors, and further studies are needed to shed light on its etiology.

  16. Epidural spinal cord stimulation for neuropathic pain: a neurosurgical multicentric Italian data collection and analysis. (United States)

    Colombo, Elena Virginia; Mandelli, Carlo; Mortini, Pietro; Messina, Giuseppe; De Marco, Nicola; Donati, Roberto; Irace, Claudio; Landi, Andrea; Lavano, Angelo; Mearini, Massimo; Podetta, Stefano; Servello, Domenico; Zekaj, Edvin; Valtulina, Carlo; Dones, Ivano


    Spinal cord stimulation (SCS) is a technique used worldwide to treat several types of chronic neuropathic pain refractory to any conservative treatment. The aim of this data collection is to enforce evidence of SCS effectiveness on neuropathic chronic pain reported in the literature and to speculate on the usefulness of the trial period in determining the long-term efficacy. Moreover, the very low percentage of undesired side effects and complications reported in our case series suggests that all implants should be performed by similarly well-trained and experienced professionals. A multicentric data collection on a common database from 11 Italian neurosurgical departments started 3 years ago. Two different types of electrodes (paddle or percutaneous leads) were used. Of 122 patients, 73 % (N = 89) were submitted to a trial period, while the remaining patients underwent the immediate permanent implant (N = 33). Statistical comparisons of continuous variables between groups were performed. Most of the patients (80 %) had predominant pain to their lower limbs, while only 17 % of patients had prevalent axial pain. Significant reduction in pain, as measured by variation in visual analogue scale (VAS) score, was observed at least 1 year after implantation in 63.8 % of the cases, 59.5 % of patients who underwent a test trial and 71.4 % of patients who underwent permanent implant at once. No statistical differences were found between the lower-limb pain group and the axial pain group. No relevant differences in long-term outcomes were observed in previously tested patients compared with patients implanted at once. Through this analysis we hope to recruit new centres, to give more scientific value to our results.

  17. A comparative study of effect of sevoflurane on intubating conditions with rocuronium in neurosurgical patients

    Directory of Open Access Journals (Sweden)

    Saikat Mitra


    Full Text Available Background and Aims: Rocuronium may not always be the preferred relaxant for rapid sequence intubation. When 2% sevoflurane is used in conjunction with rocuronium, it may reduce the time required for achieving complete skeletal muscle relaxation with the intubating dose of rocuronium. Methods: This study was prospective, randomised, double-blind in nature and compared the effect of sevoflurane on intubation time and intubating conditions when used along with rocuronium. Thirty adult patients belonging to American Society of Anesthesiologists physical status Grades 1 and 2, of either gender aged between 30 and 65 years undergoing neurosurgical operations were randomly allocated into two equal groups: Group R received 0.8 mg/kg rocuronium, and Group RS received 0.8 mg/kg of rocuronium with 2% sevoflurane. Onset time of intubation was assessed using train-of-four stimuli. The intubating conditions were compared using the Cooper scoring system and the haemodynamic responses were compared between the two groups. Results: The onset time of intubation was 101.73 ± 10.28 s in Group R and 60.4 ± 4.1 s in Group RS (P < 0.001, with excellent intubating conditions in both groups and without any adverse effects. Significant differences in heart rate and mean arterial pressure were seen immediately after intubation, at 1 and 3 min (P < 0.05 between the two groups. Conclusion: Rocuronium 0.8 mg/kg along with 2% sevoflurane provides excellent intubating conditions within 60-66 s from its administration.

  18. Syria civil war: Outcomes of humanitarian neurosurgical care provided to Syrian wounded refugees in Israel. (United States)

    Barhoum, Masad; Tobias, Samuel; Elron, Moshe; Sharon, Aviram; Heija, Tariq; Soustiel, Jean F


    As an expected consequence of the civil war in Syria, emergent neurosurgical care for battlefield trauma has been provided for severely head-injured Syrians transferred to Northern Israel. Sixty-six patients suffering from brain injury were brought to the border and then referred to the institution after initial resuscitation. Both the time and type of injury were recorded based on paramedic testimony, forensic material or on details provided by patients. A retrospective analysis of all medical charts and imaging material was performed. Most injuries were combat-related, either caused by blast (13.6%), shrapnel (24.2%), assault (28.8%) or gunshot wound (15.2%). Only a minority of patients (18.2%) suffered from injuries that were not directly caused by weapon. A total of 55 surgical procedures were performed in 46 out of 66 patients, including craniotomies in 40 patients, burr hole alone for placement of intraparenchymal intracranial pressure (ICP) sensor in nine instances and ventricle peritoneal shunt in two patients. Decompressive craniectomy was used only for the treatment of gunshot wound and was performed in eight out of 10 patients. The most common complication consisted in cerebrospinal fluid fistulas (16.7%). Post-operative infections occurred in seven patients (10.6%). Short-term outcomes were favourable in 60.7%, with a mortality rate of 4.5%. The present findings suggest that aggressive surgery and neuro-intensive care measures may lead to good functional results, even in the presence of seemingly devastating injuries in some selected patients.

  19. Neurosurgical virtual reality simulation metrics to assess psychomotor skills during brain tumor resection. (United States)

    Azarnoush, Hamed; Alzhrani, Gmaan; Winkler-Schwartz, Alexander; Alotaibi, Fahad; Gelinas-Phaneuf, Nicholas; Pazos, Valérie; Choudhury, Nusrat; Fares, Jawad; DiRaddo, Robert; Del Maestro, Rolando F


    Virtual reality simulator technology together with novel metrics could advance our understanding of expert neurosurgical performance and modify and improve resident training and assessment. This pilot study introduces innovative metrics that can be measured by the state-of-the-art simulator to assess performance. Such metrics cannot be measured in an operating room and have not been used previously to assess performance. Three sets of performance metrics were assessed utilizing the NeuroTouch platform in six scenarios with simulated brain tumors having different visual and tactile characteristics. Tier 1 metrics included percentage of brain tumor resected and volume of simulated "normal" brain tissue removed. Tier 2 metrics included instrument tip path length, time taken to resect the brain tumor, pedal activation frequency, and sum of applied forces. Tier 3 metrics included sum of forces applied to different tumor regions and the force bandwidth derived from the force histogram. The results outlined are from a novice resident in the second year of training and an expert neurosurgeon. The three tiers of metrics obtained from the NeuroTouch simulator do encompass the wide variability of technical performance observed during novice/expert resections of simulated brain tumors and can be employed to quantify the safety, quality, and efficiency of technical performance during simulated brain tumor resection. Tier 3 metrics derived from force pyramids and force histograms may be particularly useful in assessing simulated brain tumor resections. Our pilot study demonstrates that the safety, quality, and efficiency of novice and expert operators can be measured using metrics derived from the NeuroTouch platform, helping to understand how specific operator performance is dependent on both psychomotor ability and cognitive input during multiple virtual reality brain tumor resections.

  20. Epidemiology of Mild Traumatic Brain Injury with Intracranial Hemorrhage: Focusing Predictive Models for Neurosurgical Intervention. (United States)

    Orlando, Alessandro; Levy, A Stewart; Carrick, Matthew M; Tanner, Allen; Mains, Charles W; Bar-Or, David


    To outline differences in neurosurgical intervention (NI) rates between intracranial hemorrhage (ICH) types in mild traumatic brain injuries and help identify which ICH types are most likely to benefit from creation of predictive models for NI. A multicenter retrospective study of adult patients spanning 3 years at 4 U.S. trauma centers was performed. Patients were included if they presented with mild traumatic brain injury (Glasgow Coma Scale score 13-15) with head CT scan positive for ICH. Patients were excluded for skull fractures, "unspecified hemorrhage," or coagulopathy. Primary outcome was NI. Stepwise multivariable logistic regression models were built to analyze the independent association between ICH variables and outcome measures. The study comprised 1876 patients. NI rate was 6.7%. There was a significant difference in rate of NI by ICH type. Subdural hematomas had the highest rate of NI (15.5%) and accounted for 78% of all NIs. Isolated subarachnoid hemorrhages had the lowest, nonzero, NI rate (0.19%). Logistic regression models identified ICH type as the most influential independent variable when examining NI. A model predicting NI for isolated subarachnoid hemorrhages would require 26,928 patients, but a model predicting NI for isolated subdural hematomas would require only 328 patients. This study highlighted disparate NI rates among ICH types in patients with mild traumatic brain injury and identified mild, isolated subdural hematomas as most appropriate for construction of predictive NI models. Increased health care efficiency will be driven by accurate understanding of risk, which can come only from accurate predictive models. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Online constrained model-based reinforcement learning

    CSIR Research Space (South Africa)

    Van Niekerk, B


    Full Text Available Constrained Model-based Reinforcement Learning Benjamin van Niekerk School of Computer Science University of the Witwatersrand South Africa Andreas Damianou∗ Cambridge, UK Benjamin Rosman Council for Scientific and Industrial Research, and School... MULTIPLE SHOOTING Using direct multiple shooting (Bock and Plitt, 1984), problem (1) can be transformed into a structured non- linear program (NLP). First, the time horizon [t0, t0 + T ] is partitioned into N equal subintervals [tk, tk+1] for k = 0...

  2. Statistical models based on conditional probability distributions

    International Nuclear Information System (INIS)

    Narayanan, R.S.


    We present a formulation of statistical mechanics models based on conditional probability distribution rather than a Hamiltonian. We show that it is possible to realize critical phenomena through this procedure. Closely linked with this formulation is a Monte Carlo algorithm, in which a configuration generated is guaranteed to be statistically independent from any other configuration for all values of the parameters, in particular near the critical point. (orig.)

  3. PV panel model based on datasheet values

    DEFF Research Database (Denmark)

    Sera, Dezso; Teodorescu, Remus; Rodriguez, Pedro


    This work presents the construction of a model for a PV panel using the single-diode five-parameters model, based exclusively on data-sheet parameters. The model takes into account the series and parallel (shunt) resistance of the panel. The equivalent circuit and the basic equations of the PV cell....... Based on these equations, a PV panel model, which is able to predict the panel behavior in different temperature and irradiance conditions, is built and tested....

  4. Impact of the Accreditation Council for Graduate Medical Education work-hour regulations on neurosurgical resident education and productivity. (United States)

    Jagannathan, Jay; Vates, G Edward; Pouratian, Nader; Sheehan, Jason P; Patrie, James; Grady, M Sean; Jane, John A


    Recently, the Institute of Medicine examined resident duty hours and their impact on patient safety. Experts have suggested that reducing resident work hours to 56 hours per week would further decrease medical errors. Although some reports have indicated that cutbacks in resident duty hours reduce errors and make resident life safer, few authors have specifically analyzed the effect of the Accreditation Council for Graduate Medical Education (ACGME) duty-hour limits on neurosurgical resident education and the perceived quality of training. The authors have evaluated multiple objective surrogate markers of resident performance and quality of training to determine the impact of the 80-hour workweek. The United States Medical Licensing Examination (USMLE) Step 1 data on neurosurgical applicants entering ACGME-accredited programs between 1998 and 2007 (before and after the implementation of the work-hour rules) were obtained from the Society of Neurological Surgeons. The American Board of Neurological Surgery (ABNS) written examination scores for this group of residents were also acquired. Resident registration for and presentations at the American Association of Neurological Surgeons (AANS) annual meetings between 2002 and 2007 were examined as a measure of resident academic productivity. As a case example, the authors analyzed the distribution of resident training hours in the University of Virginia (UVA) neurosurgical training program before and after the institution of the 80-hour workweek. Finally, program directors and chief residents in ACGME-accredited programs were surveyed regarding the effects of the 80-hour workweek on patient care, resident training, surgical experience, patient safety, and patient access to quality care. Respondents were also queried about their perceptions of a 56-hour workweek. Despite stable mean USMLE Step 1 scores for matched applicants to neurosurgery programs between 2000 and 2008, ABNS written examination scores for residents

  5. e-Government Maturity Model Based on Systematic Review and Meta-Ethnography Approach

    Directory of Open Access Journals (Sweden)

    Darmawan Napitupulu


    Full Text Available Maturity model based on e-Government portal has been developed by a number of researchers both individually and institutionally, but still scattered in various journals and conference articles and can be said to have a different focus with each other, both in terms of stages and features. The aim of this research is conducting a study to integrate a number of maturity models existing today in order to build generic maturity model based on e-Government portal. The method used in this study is Systematic Review with meta-ethnography qualitative approach. Meta-ethnography, which is part of Systematic Review method, is a technique to perform data integration to obtain theories and concepts with a new level of understanding that is deeper and thorough. The result obtained is a maturity model based on e-Government portal that consists of 7 (seven stages, namely web presence, interaction, transaction, vertical integration, horizontal integration, full integration, and open participation. These seven stages are synthesized from the 111 key concepts related to 25 studies of maturity model based e-Government portal. The maturity model resulted is more comprehensive and generic because it is an integration of models (best practices that exists today.

  6. Breaking bad news to a prospective cross-sectional sample of patients’ relatives in a Nigerian neurosurgical service

    Directory of Open Access Journals (Sweden)

    Amos Olufemi Adeleye


    Full Text Available Objectives: Breaking of medical bad news is anecdotally deemed culturally unacceptable, even intolerable, to native Africans. We explored this hypothesis among a cohort of relatives of patients who had difficult neurosurgical diagnoses in an indigenous practice. Materials and Methods: A semi-structured, interviewer-administered questionnaire was used in a cross-sectional survey among a consecutive cohort of surrogates / relatives of concerned patients. Their opinion and preferences regarding the full disclosure of the grave neurosurgical diagnoses, and prognoses, of their wards were analysed. Results: A total of 114 patients’ relatives, 83 (72.8% females, were sampled. They were mainly young adults, mean age 40.2(SD 14.2 years; 57% had only basic literacy education; but the majority, 97%, declared themselves to have serious religious commitments. Ninety nine percent of the study participants deemed it desirable that either they or the patients concerned be told the bad news; 80.7% felt that this is best done with both patients and relations in attendance; 3.5% felt only the patients need be told. These preferences are similar to those expressed by the patients themselves in an earlier study. But a nearly significant greater proportion of patients’ relatives (15 vs 5%, p=0.06 would rather be the only ones to be told the patients’ bad news. Conclusions: This data-driven study showed that contrary to anecdotal belief about them, a cohort of native Nigerian-African surrogates of neurosurgical patients was well disposed to receiving, and appeared able to handle well, the full disclosure of difficult medical diagnostic / prognostic information.

  7. Paradoxical immune reconstitution inflammatory syndrome associated with previous Cryptococcus neoformans infection in an HIV-positive patient requiring neurosurgical intervention. (United States)

    Biagetti, Carlo; Nicola, Monica; Borderi, Marco; Pavoni, Michele; Tampellini, Livia; Verucchi, Gabriella; Chiodo, Francesco


    Immune reconstitution inflammatory syndrome (IRIS) in HIV-1-infected patients is associated with an exaggerated inflammatory response against an opportunistic infection during highly active antiretroviral therapy. The only review on IRIS associated with Criptococcus neoformans reported 21 episodes including lymphadenitis, necrotizing pneumonitis, breast and cutaneous abscess, and cryptococcomas. To our knowledge this is the first report of IRIS associated with previous meningeal criptococcal infection which required neurosurgical intervention with placement of a ventriculo-peritoneal shunt to drain a CSF cyst formed by exclusion of the temporal horn of the right lateral ventricle. We demonstrate that this procedure is possible without complications such as cryptococcal dissemination into the peritoneum.

  8. Severe Vertex Epidural Hematoma in a Child: A Case Report of a Management without Expert Neurosurgical Care

    Directory of Open Access Journals (Sweden)

    Christophe Brévart


    Full Text Available Vertex epidural hematomas (VEDHs are an uncommon situation and difficulties may be encountered in their diagnosis and management. This is more complicated when the surgical management has to be performed by general surgeons, not specialized in neurosurgery, in a remote location. It was in this context that we were brought to care in charge a 2-year-old boy who required a neurosurgical emergency rescue for a severe VEDH in Djibouti. Through the description of this case, we want to emphasize the value of developing a network of teleconsultation for the benefit of remote and isolated locations and learning basic techniques of emergency neurosurgery.

  9. SLS Navigation Model-Based Design Approach (United States)

    Oliver, T. Emerson; Anzalone, Evan; Geohagan, Kevin; Bernard, Bill; Park, Thomas


    The SLS Program chose to implement a Model-based Design and Model-based Requirements approach for managing component design information and system requirements. This approach differs from previous large-scale design efforts at Marshall Space Flight Center where design documentation alone conveyed information required for vehicle design and analysis and where extensive requirements sets were used to scope and constrain the design. The SLS Navigation Team has been responsible for the Program-controlled Design Math Models (DMMs) which describe and represent the performance of the Inertial Navigation System (INS) and the Rate Gyro Assemblies (RGAs) used by Guidance, Navigation, and Controls (GN&C). The SLS Navigation Team is also responsible for the navigation algorithms. The navigation algorithms are delivered for implementation on the flight hardware as a DMM. For the SLS Block 1-B design, the additional GPS Receiver hardware is managed as a DMM at the vehicle design level. This paper provides a discussion of the processes and methods used to engineer, design, and coordinate engineering trades and performance assessments using SLS practices as applied to the GN&C system, with a particular focus on the Navigation components. These include composing system requirements, requirements verification, model development, model verification and validation, and modeling and analysis approaches. The Model-based Design and Requirements approach does not reduce the effort associated with the design process versus previous processes used at Marshall Space Flight Center. Instead, the approach takes advantage of overlap between the requirements development and management process, and the design and analysis process by efficiently combining the control (i.e. the requirement) and the design mechanisms. The design mechanism is the representation of the component behavior and performance in design and analysis tools. The focus in the early design process shifts from the development and

  10. Development of neurosurgery in Germany: comparison of data collected by polls for 1997, 2003, and 2008 among providers of neurosurgical care. (United States)

    Steiger, Hans J; Krämer, Michael; Reulen, Hans J


    To deduce structural trends in neurosurgery in Germany by comparison of data derived from polls conducted by the Deutsche Gesellschaft für Neurochirurgie (DGNC) in 1997, 2003 and 2008. The questionnaires of the different polls probed a comparable set of issues. The data from the responding sample were extrapolated to the nationwide average or sum and compared between the different time periods. The number of identified neurosurgical departments increased from 146 to 201 during the years 1997-2008 largely as a result of the new foundation of numerous private groups. Nationwide total neurosurgical bed capacity and intensive care unit bed capacity increased modestly over the time period. The extrapolated total number of neurosurgical operations increased from 196,341 to 319,295. Although cranial and spinal neurosurgery remain the dominant subspecialties, the number of functional neurosurgical procedures and operations for pain increased more than proportionally. Outpatient procedures were established during the time period and corresponded in 2008 to a substantial proportion of the surgical volume. The total number of residents and board-certified neurosurgeons increased during the period 1997-2008 from 1513 to 1961. The proportion of residents decreased during 1997-2003 and then increased again. The number of neurosurgical operations increased in Germany proportionally to the economic growth of other service branches over the time period. Private organizations developed more than neurosurgical departments at university and other general hospitals. Work density measured as operations per physician increased during the period 1997-2008. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Least-squares model-based halftoning (United States)

    Pappas, Thrasyvoulos N.; Neuhoff, David L.


    A least-squares model-based approach to digital halftoning is proposed. It exploits both a printer model and a model for visual perception. It attempts to produce an 'optimal' halftoned reproduction, by minimizing the squared error between the response of the cascade of the printer and visual models to the binary image and the response of the visual model to the original gray-scale image. Conventional methods, such as clustered ordered dither, use the properties of the eye only implicitly, and resist printer distortions at the expense of spatial and gray-scale resolution. In previous work we showed that our printer model can be used to modify error diffusion to account for printer distortions. The modified error diffusion algorithm has better spatial and gray-scale resolution than conventional techniques, but produces some well known artifacts and asymmetries because it does not make use of an explicit eye model. Least-squares model-based halftoning uses explicit eye models and relies on printer models that predict distortions and exploit them to increase, rather than decrease, both spatial and gray-scale resolution. We have shown that the one-dimensional least-squares problem, in which each row or column of the image is halftoned independently, can be implemented with the Viterbi's algorithm. Unfortunately, no closed form solution can be found in two dimensions. The two-dimensional least squares solution is obtained by iterative techniques. Experiments show that least-squares model-based halftoning produces more gray levels and better spatial resolution than conventional techniques. We also show that the least- squares approach eliminates the problems associated with error diffusion. Model-based halftoning can be especially useful in transmission of high quality documents using high fidelity gray-scale image encoders. As we have shown, in such cases halftoning can be performed at the receiver, just before printing. Apart from coding efficiency, this approach

  12. Model-Based Motion Tracking of Infants

    DEFF Research Database (Denmark)

    Olsen, Mikkel Damgaard; Herskind, Anna; Nielsen, Jens Bo


    Even though motion tracking is a widely used technique to analyze and measure human movements, only a few studies focus on motion tracking of infants. In recent years, a number of studies have emerged focusing on analyzing the motion pattern of infants, using computer vision. Most of these studies...... are based on 2D images, but few are based on 3D information. In this paper, we present a model-based approach for tracking infants in 3D. The study extends a novel study on graph-based motion tracking of infants and we show that the extension improves the tracking results. A 3D model is constructed...

  13. Model-Based Power Plant Master Control

    Energy Technology Data Exchange (ETDEWEB)

    Boman, Katarina; Thomas, Jean; Funkquist, Jonas


    The main goal of the project has been to evaluate the potential of a coordinated master control for a solid fuel power plant in terms of tracking capability, stability and robustness. The control strategy has been model-based predictive control (MPC) and the plant used in the case study has been the Vattenfall power plant Idbaecken in Nykoeping. A dynamic plant model based on nonlinear physical models was used to imitate the true plant in MATLAB/SIMULINK simulations. The basis for this model was already developed in previous Vattenfall internal projects, along with a simulation model of the existing control implementation with traditional PID controllers. The existing PID control is used as a reference performance, and it has been thoroughly studied and tuned in these previous Vattenfall internal projects. A turbine model was developed with characteristics based on the results of steady-state simulations of the plant using the software EBSILON. Using the derived model as a representative for the actual process, an MPC control strategy was developed using linearization and gain-scheduling. The control signal constraints (rate of change) and constraints on outputs were implemented to comply with plant constraints. After tuning the MPC control parameters, a number of simulation scenarios were performed to compare the MPC strategy with the existing PID control structure. The simulation scenarios also included cases highlighting the robustness properties of the MPC strategy. From the study, the main conclusions are: - The proposed Master MPC controller shows excellent set-point tracking performance even though the plant has strong interactions and non-linearity, and the controls and their rate of change are bounded. - The proposed Master MPC controller is robust, stable in the presence of disturbances and parameter variations. Even though the current study only considered a very small number of the possible disturbances and modelling errors, the considered cases are

  14. Diagnosis and Model Based Identification of a Coupling Misalignment

    Directory of Open Access Journals (Sweden)

    P. Pennacchi


    Full Text Available This paper is focused on the application of two different diagnostic techniques aimed to identify the most important faults in rotating machinery as well as on the simulation and prediction of the frequency response of rotating machines. The application of the two diagnostics techniques, the orbit shape analysis and the model based identification in the frequency domain, is described by means of an experimental case study that concerns a gas turbine-generator unit of a small power plant whose rotor-train was affected by an angular misalignment in a flexible coupling, caused by a wrong machine assembling. The fault type is identified by means of the orbit shape analysis, then the equivalent bending moments, which enable the shaft experimental vibrations to be simulated, have been identified using a model based identification method. These excitations have been used to predict the machine vibrations in a large rotating speed range inside which no monitoring data were available. To the best of the authors' knowledge, this is the first case of identification of coupling misalignment and prediction of the consequent machine behaviour in an actual size rotating machinery. The successful results obtained emphasise the usefulness of integrating common condition monitoring techniques with diagnostic strategies.

  15. Aggressive or conservative management in extradural hematomas in children – a challenging neurosurgical choice

    Directory of Open Access Journals (Sweden)

    Tascu A.


    Full Text Available epidural hematomas (EDH in children appear as a consequence of head trauma. Although emergency surgical intervention was the classical neurosurgical treatment for EDH, lately there has been observed a tendency to replace operation by conservative management, whenever the neurological status and imaging appearance allows it. The aim of this article is to present our experience in treating EDH in children 0-3 years old and to establish a management protocol for EDH in infants, by evaluating the clinical and neuroimaging status, of both surgically and conservatively treated patients, from hospital admission to discharge. Retrospective study includes 52 patients diagnosed with an extradural hematoma, admitted in the First Neurosurgery Department of the Clinical Hospital ‘Bagdasar-Arseni’ in Bucharest, from January 2004 to December 2013. The patients were identified by diagnosis from the clinic’s database; clinical and imaging data was extracted from the patient’s individual records and crosschecked with the operating protocols. Cerebral CT scan was the preferred imaging investigation for diagnosis. Our study includes 52 patients (26 boys and 26 girls, with a mean age of 14.5 months (range 6 weeks - 3 years old. 25 patients were surgically treated, while the other 27 received symptomatic medication and were monitored clinically and by imaging exams. The most frequent clinical manifestations were intracranial hypertension (21 patients and psychomotor agitation (19 patients. The traumatic mechanisms were: accidental falling (38 patients, blunt head trauma (3 patients, road accident (2 patients, unspecified (8 patients other causes (1 patient. Based on the Glasgow Coma Scale classification of TBI, 39 patients suffered a mild TBI, 7 a moderate TBI and 6 patients suffered a severe TBI. Most of the patients had a good recovery; there was a total of two deaths. The most common location for the EDHs was parietal (20 patients and temporal-parietal (11

  16. Evaluation of acute normovolemic hemodilution and autotransfusion in neurosurgical patients undergoing excision of intracranial meningioma

    Directory of Open Access Journals (Sweden)

    Imtiaz A Naqash


    that acute normovolemic hemodilution up to a target hematocrit of 30% is safe and effective in reducing the need for homologous blood in neurosurgical patients undergoing excision of intracranial meningioma.

  17. SLS Model Based Design: A Navigation Perspective (United States)

    Oliver, T. Emerson; Anzalone, Evan; Park, Thomas; Geohagan, Kevin


    The SLS Program has implemented a Model-based Design (MBD) and Model-based Requirements approach for managing component design information and system requirements. This approach differs from previous large-scale design efforts at Marshall Space Flight Center where design documentation alone conveyed information required for vehicle design and analysis and where extensive requirements sets were used to scope and constrain the design. The SLS Navigation Team is responsible for the Program-controlled Design Math Models (DMMs) which describe and represent the performance of the Inertial Navigation System (INS) and the Rate Gyro Assemblies (RGAs) used by Guidance, Navigation, and Controls (GN&C). The SLS Navigation Team is also responsible for navigation algorithms. The navigation algorithms are delivered for implementation on the flight hardware as a DMM. For the SLS Block 1B design, the additional GPS Receiver hardware model is managed as a DMM at the vehicle design level. This paper describes the models, and discusses the processes and methods used to engineer, design, and coordinate engineering trades and performance assessments using SLS practices as applied to the GN&C system, with a particular focus on the navigation components.

  18. Sandboxes for Model-Based Inquiry (United States)

    Brady, Corey; Holbert, Nathan; Soylu, Firat; Novak, Michael; Wilensky, Uri


    In this article, we introduce a class of constructionist learning environments that we call Emergent Systems Sandboxes ( ESSs), which have served as a centerpiece of our recent work in developing curriculum to support scalable model-based learning in classroom settings. ESSs are a carefully specified form of virtual construction environment that support students in creating, exploring, and sharing computational models of dynamic systems that exhibit emergent phenomena. They provide learners with "entity"-level construction primitives that reflect an underlying scientific model. These primitives can be directly "painted" into a sandbox space, where they can then be combined, arranged, and manipulated to construct complex systems and explore the emergent properties of those systems. We argue that ESSs offer a means of addressing some of the key barriers to adopting rich, constructionist model-based inquiry approaches in science classrooms at scale. Situating the ESS in a large-scale science modeling curriculum we are implementing across the USA, we describe how the unique "entity-level" primitive design of an ESS facilitates knowledge system refinement at both an individual and social level, we describe how it supports flexible modeling practices by providing both continuous and discrete modes of executability, and we illustrate how it offers students a variety of opportunities for validating their qualitative understandings of emergent systems as they develop.

  19. Advanced MR imaging for the optimal micro neurosurgical planning in patients with the congential spinal meningeal cysts

    International Nuclear Information System (INIS)

    Purvina, J.; Jansone, A.; Krumina, G.; Dzelzite, S.; Platkajis, A.; Ozolins, H.; Dzelzitis, J.


    The extramedullar meningeal cysts are congential anomalies of the spinal canal. The neurological manifestation - the syndromes of radicular pain and the dysfunctions of the pelvic organs are indicators for the neurosurgical treatment. The most complete classification of distinguish the different types of these anomalies is the Nabor's classification. The congential anomalies (malformations) are conventionally diagnosed by TC or conventional MR imaging techniques. These methods can't give a precise answer to the Nabor's classification. The new MR sequences offer the possibility to diagnose these anomalies more precisely. Purpose: to create a new MR protocol for a precise topical diagnostic of the meningeal cysts according to the contemporary embriogenetical, neurological and neurosurgical classification. Conclusions: For the optimal topographical visualisation of the congential spinal meningeal cysts MR in 3 orthogonal planes must be performed. The thin slice techniques with the specific parameters for better visualisation of the nerve roots are necessary. The thin slice, fat suppressed MR sequences are very important for the differential diagnosis of the extradural meningeal cysts from the dermoids, para- and infraspinal fat collections. They are very useful in choosing the optimal microneurosurgical way of the surgical treatment. (authors)

  20. The Preferred Learning Styles of Neurosurgeons, Neurosurgery Residents, and Neurology Residents: Implications in the Neurosurgical Field. (United States)

    Lai, Hung-Yi; Lee, Ching-Yi; Chiu, Angela; Lee, Shih-Tseng


    To delineate the learning style that best defines a successful practitioner in the field of neurosurgery by using a validated learning style inventory. The Kolb Learning Style Inventory, a validated assessment tool, was administered to all practicing neurosurgeons, neurosurgical residents, and neurology residents employed at Chang Gung Memorial Hospital, an institution that provides primary and tertiary clinical care in 3 locations, Linkou, Kaohsiung, and Chiayi. There were 81 participants who entered the study, and all completed the study. Neurosurgeons preferred the assimilating learning style (52%), followed by the diverging learning style (39%). Neurosurgery residents were slightly more evenly distributed across the learning styles; however, they still favored assimilating (32%) and diverging (41%). Neurology residents had the most clearly defined preferred learning style with assimilating (76%) obtaining the large majority and diverging (12%) being a distant second. The assimilating and diverging learning styles are the preferred learning styles among neurosurgeons, neurosurgery residents, and neurology residents. The assimilating learning style typically is the primary learning style for neurosurgeons and neurology residents. Neurosurgical residents start off with a diverging learning style and progress toward an assimilating learning style as they work toward becoming practicing neurosurgeons. The field of neurosurgery has limited opportunities for active experimentation, which may explain why individuals who prefer reflective observation are more likely to succeed in this field. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. "I am not afraid of death"-a survey on preferences concerning neurosurgical interventions among patients over 75 years. (United States)

    Unterhofer, Claudia; Ho, Wing Mann; Wittlinger, Katrin; Thomé, Claudius; Ortler, Martin


    Treatment decisions in elderly patients with traumatic brain injury (TBI) are mainly determined by trauma severity and patient age. The aim of this study was to explore personal preferences of potential patients regarding life-prolonging neurosurgical interventions by interviewing ambulatory, autonomous elderly people. One hundred consecutive patients older than 75 years frequenting the outpatient clinic of the Department of Neurosurgery were interviewed about their attitudes regarding the hypothetical case of an 81-year-old patient with TBI and a space-occupying acute subdural hematoma (aSDH) using a 21-point questionnaire. Fifty-one percent of the consulted persons declined life-prolonging surgical measures. If surgery was associated with physical disability, 68% of the people wished no surgery. In case of cognitive impairment after surgery, 91% were against any surgical intervention. The majority feared being a burden to relatives (76%) and becoming unable to master an independent life (75%). Four-fifths of the interviewed patients (82%) were not afraid of death. The majority of elderly patients only consent to surgical measures if no relevant disabilities are involved and if they can return to their previous life. These findings need consideration in case of life-threatening neurosurgical emergencies as well as in the surgical treatment of elderly patients in general.

  2. Safety and Efficacy of Intravenous Clevidipine for the Perioperative Control of Acute Hypertension in Neurosurgical Patients: A Dose Update

    Directory of Open Access Journals (Sweden)

    Kristin I Brower


    Full Text Available Clevidipine is a third-generation dihydropyridine calcium channel blocker approved in 2008 by the Food and Drug Administration for parenteral therapy of arterial hypertension. The high degree of lipophilicity of clevidipine provides a rapid onset of action and ease of titration to reach the desired clinical effect. Since its introduction into clinical practice, clevidipine has been shown to be safe and effective for perioperative use in patients undergoing procedures in which rapid and effective blood pressure control is essential. In 2011, clevidipine received institutional approval for intraoperative use during neurosurgical procedures and for postoperative blood pressure control in the Post-Anesthesia Care Unit and Surgical Intensive Care Unit during the first 24 hours after surgery. This review describes the efficacy and safety of intravenous clevidipine in intraoperative blood pressure management during neurosurgical procedures in 11 patients over a period of 3 months. The evaluation revealed that lower rates of clevidipine infusion than previously documented in the literature achieved blood pressure control within the desired limits during surgery while avoiding dose-related adverse reactions.

  3. New Directions in 3D Medical Modeling: 3D-Printing Anatomy and Functions in Neurosurgical Planning (United States)

    Árnadóttir, Íris; Gíslason, Magnús; Ólafsson, Ingvar


    This paper illustrates the feasibility and utility of combining cranial anatomy and brain function on the same 3D-printed model, as evidenced by a neurosurgical planning case study of a 29-year-old female patient with a low-grade frontal-lobe glioma. We herein report the rapid prototyping methodology utilized in conjunction with surgical navigation to prepare and plan a complex neurosurgery. The method introduced here combines CT and MRI images with DTI tractography, while using various image segmentation protocols to 3D model the skull base, tumor, and five eloquent fiber tracts. This 3D model is rapid-prototyped and coregistered with patient images and a reported surgical navigation system, establishing a clear link between the printed model and surgical navigation. This methodology highlights the potential for advanced neurosurgical preparation, which can begin before the patient enters the operation theatre. Moreover, the work presented here demonstrates the workflow developed at the National University Hospital of Iceland, Landspitali, focusing on the processes of anatomy segmentation, fiber tract extrapolation, MRI/CT registration, and 3D printing. Furthermore, we present a qualitative and quantitative assessment for fiber tract generation in a case study where these processes are applied in the preparation of brain tumor resection surgery. PMID:29065569

  4. New Directions in 3D Medical Modeling: 3D-Printing Anatomy and Functions in Neurosurgical Planning

    Directory of Open Access Journals (Sweden)

    Paolo Gargiulo


    Full Text Available This paper illustrates the feasibility and utility of combining cranial anatomy and brain function on the same 3D-printed model, as evidenced by a neurosurgical planning case study of a 29-year-old female patient with a low-grade frontal-lobe glioma. We herein report the rapid prototyping methodology utilized in conjunction with surgical navigation to prepare and plan a complex neurosurgery. The method introduced here combines CT and MRI images with DTI tractography, while using various image segmentation protocols to 3D model the skull base, tumor, and five eloquent fiber tracts. This 3D model is rapid-prototyped and coregistered with patient images and a reported surgical navigation system, establishing a clear link between the printed model and surgical navigation. This methodology highlights the potential for advanced neurosurgical preparation, which can begin before the patient enters the operation theatre. Moreover, the work presented here demonstrates the workflow developed at the National University Hospital of Iceland, Landspitali, focusing on the processes of anatomy segmentation, fiber tract extrapolation, MRI/CT registration, and 3D printing. Furthermore, we present a qualitative and quantitative assessment for fiber tract generation in a case study where these processes are applied in the preparation of brain tumor resection surgery.

  5. Working Conditions and Lifestyle of Female Surgeons Affiliated to the Japan Neurosurgical Society: Findings of Individual and Institutional Surveys. (United States)

    Fujimaki, Takamitsu; Shibui, Soichiro; Kato, Yoko; Matsumura, Akira; Yamasaki, Mami; Date, Isao; Hongo, Kazuhiro; Kuroda, Satoshi; Matsumae, Mitsunori; Nakao, Naoyuki; Sakurada, Kaori; Shimokawa, Shoko; Kayama, Takamasa


    To investigate the working conditions of female neurosurgeons in Japan, two surveys were conducted by The Japan Neurosurgical Society: one involving female neurosurgeons themselves and the other involving the chiefs of neurosurgical departments. The responses were received from 224 (43.8%) female neurosurgeons and 496 (61.2%) departmental chiefs. About half (50.2%) of the female neurosurgeons were married and 39.2% had children (average number of children, 1.27). Their work was full-time in 80.6% of cases; on average, they worked 51.9 h per week, had night duty 2.8 times per month, and had 5.7 days off per month. Many of them stated that they were satisfied with their job status, but about half of them reported difficulty in maintaining a correct work-life balance. Among the institutions surveyed, 29% had female neurosurgeons. The survey of departmental chiefs revealed that the proxies for maternity leave were not available at most institutions, and that there was only limited availability of night child care (41%) or sick child care (39%); female neurosurgeons did not appear to be well-informed of these support systems. These findings suggest that apart from systematic approaches already in place, female neurosurgeons would prefer to have more understanding from their peers and chiefs.

  6. A new mechatronic assistance system for the neurosurgical operating theatre: implementation, assessment of accuracy and application concepts. (United States)

    Rachinger, Jens; Bumm, Klaus; Wurm, Jochen; Bohr, Christopher; Nissen, Urs; Dannenmann, Tim; Buchfelder, Michael; Iro, Heinrich; Nimsky, Christopher


    To introduce a new robotic system to the field of neurosurgery and report on a preliminary assessment of accuracy as well as on envisioned application concepts. Based on experience with another system (Evolution 1, URS Inc., Schwerin, Germany), technical advancements are discussed. The basic module is an industrial 6 degrees of freedom robotic arm with a modified control element. The system combines frameless stereotaxy, robotics, and endoscopy. The robotic reproducibility error and the overall error were evaluated. For accuracy testing CT markers were placed on a cadaveric head and pinpointed with the robot's tool tip, both fully automated and telemanipulatory. Applicability in a clinical setting, user friendliness, safety and flexibility were assessed. The new system is suitable for use in the neurosurgical operating theatre. Hard- and software are user-friendly and flexible. The mean reproducibility error was 0.052-0.062 mm, the mean overall error was 0.816 mm. The system is less cumbersome and much easier to use than the Evolution 1. With its user-friendly interface and reliable safety features, its high application accuracy and flexibility, the new system is a versatile robotic platform for various neurosurgical applications. Adaptations for different applications are currently being realized. Copyright (c) 2007 S. Karger AG, Basel.

  7. [Model-based biofuels system analysis: a review]. (United States)

    Chang, Shiyan; Zhang, Xiliang; Zhao, Lili; Ou, Xunmin


    Model-based system analysis is an important tool for evaluating the potential and impacts of biofuels, and for drafting biofuels technology roadmaps and targets. The broad reach of the biofuels supply chain requires that biofuels system analyses span a range of disciplines, including agriculture/forestry, energy, economics, and the environment. Here we reviewed various models developed for or applied to modeling biofuels, and presented a critical analysis of Agriculture/Forestry System Models, Energy System Models, Integrated Assessment Models, Micro-level Cost, Energy and Emission Calculation Models, and Specific Macro-level Biofuel Models. We focused on the models' strengths, weaknesses, and applicability, facilitating the selection of a suitable type of model for specific issues. Such an analysis was a prerequisite for future biofuels system modeling, and represented a valuable resource for researchers and policy makers.

  8. Intelligent Transportation and Evacuation Planning A Modeling-Based Approach

    CERN Document Server

    Naser, Arab


    Intelligent Transportation and Evacuation Planning: A Modeling-Based Approach provides a new paradigm for evacuation planning strategies and techniques. Recently, evacuation planning and modeling have increasingly attracted interest among researchers as well as government officials. This interest stems from the recent catastrophic hurricanes and weather-related events that occurred in the southeastern United States (Hurricane Katrina and Rita). The evacuation methods that were in place before and during the hurricanes did not work well and resulted in thousands of deaths. This book offers insights into the methods and techniques that allow for implementing mathematical-based, simulation-based, and integrated optimization and simulation-based engineering approaches for evacuation planning. This book also: Comprehensively discusses the application of mathematical models for evacuation and intelligent transportation modeling Covers advanced methodologies in evacuation modeling and planning Discusses principles a...

  9. Mechatronic Model Based Computed Torque Control of a Parallel Manipulator

    Directory of Open Access Journals (Sweden)

    Zhiyong Yang


    Full Text Available With high speed and accuracy the parallel manipulators have wide application in the industry, but there still exist many difficulties in the actual control process because of the time-varying and coupling. Unfortunately, the present-day commercial controlles cannot provide satisfying performance for its single axis linear control only. Therefore, aimed at a novel 2-DOF (Degree of Freedom parallel manipulator called Diamond 600, a motor-mechanism coupling dynamic model based control scheme employing the computed torque control algorithm are presented in this paper. First, the integrated dynamic coupling model is deduced, according to equivalent torques between the mechanical structure and the PM (Permanent Magnetism servomotor. Second, computed torque controller is described in detail for the above proposed model. At last, a series of numerical simulations and experiments are carried out to test the effectiveness of the system, and the results verify the favourable tracking ability and robustness.

  10. Mechatronic Model Based Computed Torque Control of a Parallel Manipulator

    Directory of Open Access Journals (Sweden)

    Zhiyong Yang


    Full Text Available With high speed and accuracy the parallel manipulators have wide application in the industry, but there still exist many difficulties in the actual control process because of the time-varying and coupling. Unfortunately, the present-day commercial controlles cannot provide satisfying performance for its single axis linear control only. Therefore, aimed at a novel 2-DOF (Degree of Freedom parallel manipulator called Diamond 600, a motor-mechanism coupling dynamic model based control scheme employing the computed torque control algorithm are presented in this paper. First, the integrated dynamic coupling model is deduced, according to equivalent torques between the mechanical structure and the PM (Permanent Magnetism servomotor. Second, computed torque controller is described in detail for the above proposed model. At last, a series of numerical simulations and experiments are carried out to test the effectiveness of the system, and the results verify the favourable tracking ability and robustness.

  11. Unifying Model-Based and Reactive Programming within a Model-Based Executive (United States)

    Williams, Brian C.; Gupta, Vineet; Norvig, Peter (Technical Monitor)


    Real-time, model-based, deduction has recently emerged as a vital component in AI's tool box for developing highly autonomous reactive systems. Yet one of the current hurdles towards developing model-based reactive systems is the number of methods simultaneously employed, and their corresponding melange of programming and modeling languages. This paper offers an important step towards unification. We introduce RMPL, a rich modeling language that combines probabilistic, constraint-based modeling with reactive programming constructs, while offering a simple semantics in terms of hidden state Markov processes. We introduce probabilistic, hierarchical constraint automata (PHCA), which allow Markov processes to be expressed in a compact representation that preserves the modularity of RMPL programs. Finally, a model-based executive, called Reactive Burton is described that exploits this compact encoding to perform efficIent simulation, belief state update and control sequence generation.

  12. Modeling Based Decision Support Environment, Phase II (United States)

    National Aeronautics and Space Administration — Phoenix Integration's vision is the creation of an intuitive human-in-the-loop engineering environment called Decision Navigator that leverages recent advances in...

  13. Model Based Control of Refrigeration Systems

    DEFF Research Database (Denmark)

    Larsen, Lars Finn Sloth

    for automation of these procedures, that is to incorporate some "intelligence" in the control system, this project was started up. The main emphasis of this work has been on model based methods for system optimizing control in supermarket refrigeration systems. The idea of implementing a system optimizing...... control is to let an optimization procedure take over the task of operating the refrigeration system and thereby replace the role of the operator in the traditional control structure. In the context of refrigeration systems, the idea is to divide the optimizing control structure into two parts: A part...... optimizing the steady state operation "set-point optimizing control" and a part optimizing dynamic behaviour of the system "dynamical optimizing control". A novel approach for set-point optimization will be presented. The general idea is to use a prediction of the steady state, for computation of the cost...

  14. The implementation of teleneurosurgery in the management of referrals to a neurosurgical department in hospital sultanah amninah johor bahru. (United States)

    Hassan, Risdhawati; Siregar, Johari Adnan; A Rahman Mohd, Noor Azman


    Telemedicine in neurosurgery or teleneurosurgery has been widely used for transmission of clinical data and images throughout the country since its implementation in 2006. The impact is a reduction of patient number that need to be reviewed in the level III hospitals and an increment in the number of patients that are kept in level II hospitals for observation by the primary team. This translates to reduction of unnecessary transfer of patients and subsequently cost benefits for patients and medical providers. The main aim is to determine the amount of reduction in unnecessary transfer by the implementation of teleneurosurgery in the management of referrals to neurosurgical department in Hospital Sultanah Amninah Johor Bahru (HSAJB). Other factors associated with transfer decision are also evaluated. This prospective cohort study was conducted in HSAJB, Johor over four months. A total of 349 subjects referred to HSAJB are included with 12 subjects excluded. The subjects are followed up from the time of referral until three months post-referrals. Related data includes the decision before and after reviewing the radiological images on teleconsultation website with clinical data available. There was a significant reduction in the number of inter-hospital transfer. 37% of transfer is avoided and patients are best kept in their original hospitals. However, there are additional findings in which there are 20.1% of patients that thought does not require transfer based on clinical data alone, would have to be transferred when the clinical data and images are reviewed. This translates to an increment of 20.1% need to be observed in neurosurgical center. Without the images, these patients might be observed in the referral hospitals with higher risk of deterioration. Other factors that are related to transfer decision apart from images include Glasgow Coma Scale (GCS) and diagnosis. The GCS significantly associated with transfer when only clinical data is reviewed. However

  15. The challenges of managing acute extradural hematoma in a Nigerian neurosurgical center--still a long way to go. (United States)

    Emejulu, Jude Kennedy C; Uche, Enoch Ogbonnaya; Nwankwo, Ezekiel Uche


    Acute extradural hematoma (EDH) is the collection of blood in the potential space between the dura mater and endocranium within 3 days of an incident. It is usually, but not always, a neurosurgical emergency, and early treatment reduces morbidity and mortality, although the outcome is still affected by some other determinants. In Nigeria, the National Health Insurance Scheme does not cover neurosurgical cases, and patients have to pay for all of their treatment regardless of the emergency status. We evaluate epidemiologic patterns, management protocols, and outcome, especially in relation to timely operative intervention, in patients with acute extradural hematoma who presented to our recently established neurosurgical service. This prospective study comprised cases managed in our center from May 2006 to July 2013. Data of all patients with acute EDH were collected on Microsoft Excel software and complemented with hospital charts and operative records. Demographic data, etiologic factors, time interval from injury to presentation in our service, time interval from presentation to definitive treatment, and outcome were collected and analyzed. Within the 86-month study period, 1648 patients presented to our service with head injuries. Acute EDH constituted 3.03%, with a mean of 7.14 cases per year. Among the cases of acute EDH, 92% involved male patients (male-to-female ratio, 11.5:1). Peak age incidence (42%) was 21-30 years (mean, 23 years), and motorcycle road traffic accident was the most common etiologic factor (72%). Operative treatment was performed in 84% of the cases (in 57.1%, operative treatment occurred within 1 week of presentation). Conservative management was employed in 10% of cases. Mortality was 14.9%; most (10%) had severe head injury, although 2.1% had mild injury known to be associated with 0% mortality. Acute EDH is a potentially fatal condition that is easily treatable if presentation, diagnosis, and treatment occur promptly. Our outcomes could

  16. Assessment of selected quality fields of nursing care in neurosurgical wards: a prospective study of 530 people – multicenter studies

    Directory of Open Access Journals (Sweden)

    Ślusarz R


    Full Text Available Robert Ślusarz,1 Monika Biercewicz,2 Ewa Barczykowska,3 Beata Haor,4 Mariola Głowacka5 1Neurological and Neurosurgical Nursing Department, Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, 2Clinic of Geriatrics, 3Nursing Department, Collegium Medicum, Nicolaus Copernicus University, Torun, 4Faculty of Health Science, University of Humanities and Economics in Wloclawek, Wloclawek, 5Institute of Health Sciences, State School of Higher Professional Education in Plock, Plock, Poland Background: One of the elements influencing the assessment of nursing care quality is the assessment of the nurse’s functions that determine the nurse’s particular tasks. The aim of this work was to assess selected tasks involved in the nurse’s caring function, which influence nursing care quality on neurosurgical wards, on the basis of patients’ and nursing staff’s opinions.Materials and methods: The research was carried out on neurosurgical wards in Poland on a group of 455 patients and 75 nurses. In order to assess nursing care quality, an author’s original questionnaire (Questionnaire – Patient Satisfaction was used.Results: Statistically significant differences concerned particular groups (both patients and nurses in the assessment of selected issues: providing information about performed activities and operations (P=0.000 and P=0.040, respecting personal dignity and assuring discretion during the operations (P=0.000 and P=0.001, speed of response to patient’s requests (P=0.000 and P=0.000, time availability of nurses for the patient (P=0.000 and P=0.000, providing information about further self-care at home (P=0.032, P=0.008, and nurses’ attitude (kindness, courtesy, tenderness, care to patients (patient’s assessment only P=0.000.Conclusion: Selected tasks in the field of the caring function of nurses were assessed differently by particular groups. There were no statistically significant differences in the assessment of particular

  17. Short-Term Load Forecasting Model Based on Quantum Elman Neural Networks

    Directory of Open Access Journals (Sweden)

    Zhisheng Zhang


    Full Text Available Short-term load forecasting model based on quantum Elman neural networks was constructed in this paper. The quantum computation and Elman feedback mechanism were integrated into quantum Elman neural networks. Quantum computation can effectively improve the approximation capability and the information processing ability of the neural networks. Quantum Elman neural networks have not only the feedforward connection but also the feedback connection. The feedback connection between the hidden nodes and the context nodes belongs to the state feedback in the internal system, which has formed specific dynamic memory performance. Phase space reconstruction theory is the theoretical basis of constructing the forecasting model. The training samples are formed by means of K-nearest neighbor approach. Through the example simulation, the testing results show that the model based on quantum Elman neural networks is better than the model based on the quantum feedforward neural network, the model based on the conventional Elman neural network, and the model based on the conventional feedforward neural network. So the proposed model can effectively improve the prediction accuracy. The research in the paper makes a theoretical foundation for the practical engineering application of the short-term load forecasting model based on quantum Elman neural networks.

  18. A Retrospective Propensity Score-Matched Early Thromboembolic Event Analysis of Prothrombin Complex Concentrate vs Fresh Frozen Plasma for Warfarin Reversal Prior to Emergency Neurosurgical Procedures. (United States)

    Agarwal, Prateek; Abdullah, Kalil G; Ramayya, Ashwin G; Nayak, Nikhil R; Lucas, Timothy H


    Reversal of therapeutic anticoagulation prior to emergency neurosurgical procedures is required in the setting of intracranial hemorrhage. Multifactor prothrombin complex concentrate (PCC) promises rapid efficacy but may increase the probability of thrombotic complications compared to fresh frozen plasma (FFP). To compare the rate of thrombotic complications in patients treated with PCC or FFP to reverse therapeutic anticoagulation prior to emergency neurosurgical procedures in the setting of intracranial hemorrhage at a level I trauma center. Sixty-three consecutive patients on warfarin therapy presenting with intracranial hemorrhage who received anticoagulation reversal prior to emergency neurosurgical procedures were retrospectively identified between 2007 and 2016. They were divided into 2 cohorts based on reversal agent, either PCC (n = 28) or FFP (n = 35). The thrombotic complications rates within 72 h of reversal were compared using the χ 2 test. A multivariate propensity score matching analysis was used to limit the threat to interval validity from selection bias arising from differences in demographics, laboratory values, history, and clinical status. Thrombotic complications were uncommon in this neurosurgical population, occurring in 1.59% (1/63) of treated patients. There was no significant difference in the thrombotic complication rate between groups, 3.57% (1/28; PCC group) vs 0% (0/35; FFP group). Propensity score matching analysis validated this finding after controlling for any selection bias. In this limited sample, thrombotic complication rates were similar between use of PCC and FFP for anticoagulation reversal in the management of intracranial hemorrhage prior to emergency neurosurgical procedures. Copyright © 2017 by the Congress of Neurological Surgeons

  19. Model-based control of hopper dredgers

    NARCIS (Netherlands)

    Braaksma, J.


    The modern trailing suction hopper dredgers are advanced ships that are equipped with many automation systems that can be controlled with integrated computer systems from the bridge. From the operators it is expected that they generate the right set-points for all these systems. The latest ships are

  20. Diminishing musyarakah investment model based on equity (United States)

    Jaffar, Maheran Mohd; Zain, Shaharir Mohamad; Jemain, Abdul Aziz


    Most of the mudharabah and musyarakah contract funds are involved in debt financing. This does not support the theory that profit sharing contract is better than that of debt financing due to the sharing of risks and ownership of equity. Indeed, it is believed that Islamic banking is a financial model based on equity or musyarakah which emphasis on the sharing of risks, profit and loss in the investment between the investor and entrepreneur. The focus of this paper is to introduce the mathematical model that internalizes diminishing musyarakah, the sharing of profit and equity between entrepreneur and investor. The entrepreneur pays monthly-differed payment to buy out the equity that belongs to the investor (bank) where at the end of the specified period, the entrepreneur owns the business and the investor (bank) exits the joint venture. The model is able to calculate the amount of equity at any time for both parties and hence would be a guide in helping to estimate the value of investment should the entrepreneur or investor exit before the end of the specified period. The model is closer to the Islamic principles for justice and fairness.

  1. Model-Based Method for Sensor Validation (United States)

    Vatan, Farrokh


    Fault detection, diagnosis, and prognosis are essential tasks in the operation of autonomous spacecraft, instruments, and in situ platforms. One of NASA s key mission requirements is robust state estimation. Sensing, using a wide range of sensors and sensor fusion approaches, plays a central role in robust state estimation, and there is a need to diagnose sensor failure as well as component failure. Sensor validation can be considered to be part of the larger effort of improving reliability and safety. The standard methods for solving the sensor validation problem are based on probabilistic analysis of the system, from which the method based on Bayesian networks is most popular. Therefore, these methods can only predict the most probable faulty sensors, which are subject to the initial probabilities defined for the failures. The method developed in this work is based on a model-based approach and provides the faulty sensors (if any), which can be logically inferred from the model of the system and the sensor readings (observations). The method is also more suitable for the systems when it is hard, or even impossible, to find the probability functions of the system. The method starts by a new mathematical description of the problem and develops a very efficient and systematic algorithm for its solution. The method builds on the concepts of analytical redundant relations (ARRs).

  2. Model based energy benchmarking for glass furnace

    International Nuclear Information System (INIS)

    Sardeshpande, Vishal; Gaitonde, U.N.; Banerjee, Rangan


    Energy benchmarking of processes is important for setting energy efficiency targets and planning energy management strategies. Most approaches used for energy benchmarking are based on statistical methods by comparing with a sample of existing plants. This paper presents a model based approach for benchmarking of energy intensive industrial processes and illustrates this approach for industrial glass furnaces. A simulation model for a glass furnace is developed using mass and energy balances, and heat loss equations for the different zones and empirical equations based on operating practices. The model is checked with field data from end fired industrial glass furnaces in India. The simulation model enables calculation of the energy performance of a given furnace design. The model results show the potential for improvement and the impact of different operating and design preferences on specific energy consumption. A case study for a 100 TPD end fired furnace is presented. An achievable minimum energy consumption of about 3830 kJ/kg is estimated for this furnace. The useful heat carried by glass is about 53% of the heat supplied by the fuel. Actual furnaces operating at these production scales have a potential for reduction in energy consumption of about 20-25%

  3. 3-D model-based vehicle tracking. (United States)

    Lou, Jianguang; Tan, Tieniu; Hu, Weiming; Yang, Hao; Maybank, Steven J


    This paper aims at tracking vehicles from monocular intensity image sequences and presents an efficient and robust approach to three-dimensional (3-D) model-based vehicle tracking. Under the weak perspective assumption and the ground-plane constraint, the movements of model projection in the two-dimensional image plane can be decomposed into two motions: translation and rotation. They are the results of the corresponding movements of 3-D translation on the ground plane (GP) and rotation around the normal of the GP, which can be determined separately. A new metric based on point-to-line segment distance is proposed to evaluate the similarity between an image region and an instantiation of a 3-D vehicle model under a given pose. Based on this, we provide an efficient pose refinement method to refine the vehicle's pose parameters. An improved EKF is also proposed to track and to predict vehicle motion with a precise kinematics model. Experimental results with both indoor and outdoor data show that the algorithm obtains desirable performance even under severe occlusion and clutter.

  4. The use of a reconstituted collagen foil dura mater substitute in paediatric neurosurgical procedures--experience in 47 patients. (United States)

    Pettorini, Benedetta Ludovica; Tamburrini, Gianpiero; Massimi, Luca; Paternoster, Giovanna; Caldarelli, Massimo; Di Rocco, Concezio


    CSF leakage is a common complication of neurosurgical procedures, with defective dural suture thought to be the most frequent cause. We report our experience with a new collagen foil (TissuDura, Baxter Healthcare SA, Switzerland) utilized as dural substitute in paediatric neurosurgical procedures. TissuDura was used in children consecutively operated on at the department of paediatric neurosurgery, Catholic University, Rome, from March 2004 to August 2007. Children underwent surgical procedures in supratentorial, infratentorial and spinal compartments. In supratentorial and spinal procedures, the dural graft was used according to the overlay technique. In the posterior fossa procedures, the underlay technique was used. Forty-seven patients received TissuDura during surgery. Thirty-one patients underwent surgery for the removal of posterior fossa tumours, nine for supratentorial tumours and seven for spinal dysraphisms. No CSF leakage was observed following the use of TissuDura in supratentorial procedures. Two post-operative CSF leaks occurred in patients who had undergone spinal surgery. No post-operative hydrocephalus was noted in these two surgery groups. Three cases of CSF leakage occurred in patients who had undergone posterior cranial fossa surgery. All 3 cases had an associated supratentorial ventricular dilation present prior to the removal of the tumour (one case) or occurring after the tumour excision (two cases). No clinically evident adverse reactions directly related to TissuDura were observed. The main advantages of TissuDura were its apparent ability to prevent CSF leakage when utilized in a specific subset of patients, and the absence of reactions or postoperative infections.

  5. A pilot study of the utility of a laboratory-based spinal fixation training program for neurosurgical residents. (United States)

    Sundar, Swetha J; Healy, Andrew T; Kshettry, Varun R; Mroz, Thomas E; Schlenk, Richard; Benzel, Edward C


    OBJECTIVE Pedicle and lateral mass screw placement is technically demanding due to complex 3D spinal anatomy that is not easily visualized. Neurosurgical and orthopedic surgery residents must be properly trained in such procedures, which can be associated with significant complications and associated morbidity. Current training in pedicle and lateral mass screw placement involves didactic teaching and supervised placement in the operating room. The objective of this study was to assess whether teaching residents to place pedicle and lateral mass screws using navigation software, combined with practice using cadaveric specimens and Sawbones models, would improve screw placement accuracy. METHODS This was a single-blinded, prospective, randomized pilot study with 8 junior neurosurgical residents and 2 senior medical students with prior neurosurgery exposure. Both the study group and the level of training-matched control group (each group with 4 level of training-matched residents and 1 senior medical student) were exposed to a standardized didactic education regarding spinal anatomy and screw placement techniques. The study group was exposed to an additional pilot program that included a training session using navigation software combined with cadaveric specimens and accessibility to Sawbones models. RESULTS A statistically significant reduction in overall surgical error was observed in the study group compared with the control group (p = 0.04). Analysis by spinal region demonstrated a significant reduction in surgical error in the thoracic and lumbar regions in the study group compared with controls (p = 0.02 and p = 0.04, respectively). The study group also was observed to place screws more optimally in the cervical, thoracic, and lumbar regions (p = 0.02, p = 0.04, and p = 0.04, respectively). CONCLUSIONS Surgical resident education in pedicle and lateral mass screw placement is a priority for training programs. This study demonstrated that compared with a

  6. A Systematic Review and Meta-Analysis on Economic Comparison Between Endovascular Coiling Versus Neurosurgical Clipping for Ruptured Intracranial Aneurysms. (United States)

    Zhang, Xiaoxi; Li, Li; Hong, Bo; Xu, Yi; Liu, Yuan; Huang, Qinghai; Liu, Jianmin


    Healthcare expenditures and cost reduction have been under critical surveillance in all countries and are critical for policymakers. This review aims at qualitatively and quantitatively analyzing the difference of hospital costs and length of stay between endovascular coiling versus neurosurgical clipping in ruptured intracranial aneurysms (RAs). MEDLINE, the Cochrane database, Embase, and the Web of Science database were searched and evaluated independently by 2 authors according to the Newcastle-Ottawa Scale for cohort studies describing economic hospital cost or length of stay in patients with RAs. A total of 8 studies were included, describing 24,219 RAs treated with neurosurgical clipping and 24,962 RAs with endovascular coiling. Meta-analysis revealed that the total hospital costs (THCs) were similar between coiling versus clipping in RAs (standard mean difference [SMD], -0.05; 95% confidence interval [CI], -0.12 to 0.22; I 2  = 99%; P = 0.50). Subgroup analysis showed that THCs of clipping and coiling were similar in ruptured aneurysms in the United States. However, in South Korea, the THCs of coiling were significantly higher than clipping. In the long run, 1-year medical costs of endovascular treatment were significantly lower than that of clipping in RAs (SMD, 0.15; 95% CI, 0.05-0.25; I 2  = 66%; P = 0.005). In addition, the length of stay of coiled patients was significantly shorter than clipped patients (SMD, 0.29; 95% CI, 0.13-0.45; I 2  = 96%; P China, coiling was more expensive. The length of stay was much shorter in coiled patients in all countries. Copyright © 2018. Published by Elsevier Inc.

  7. A Retrospective Study on the Incidence of Seizures among Neurosurgical Patients Who Treated with Imipenem/Cilastatin or Meropenem. (United States)

    Wu, Yuanxing; Chen, Kai; Shi, Zhonghua; Wang, Qiang


    We sought to evaluate the safety of imipenem and meropenem in the treatment of infections in neurosurgical patients. An observational retrospective study was conducted of consecutive cases treated with imipenem from Sept. 2007 to Sept. 2009 and meropenem within 1 year from Sept. 2008 in Beijing Tiantan Hospital, China. Data including the dosage and duration of the drug use, occurrence of seizures and mortality outcome was collected from the electronic pharmacy records. The incidence of epilepsy, epileptic standardized morbidity rate (SMR) were reported. Attention was paid to the relationship between the use of imipenem/meropenem and the incidence of epilepsy. The imipenem patients within two years amounted to 71, with mean age 45.9±20.2 years, male to female ratio 46/25. The incidence of epilepsy was 11.3% (8 cases). Among them, 1 case occurred during treatment (1/633, 1.6/1000 patient-days), and the remaining 7 cases occurred before treatment (7/2819, 2.5/1000 patient-days), with the standardized incidence rate 0.64, 95% CI (0.08-5.18).The meropenem patients within one year amounted to 92, mean age 45.1±19.4 years, male to female ratio 51/41. The incidence of epilepsy was 6.5% (6 cases). 2 occurred during treatment (2/582, 2.0/1000 patients-hospital days) and 4 before treatment (4/2047, 3.4/1000 patients-inpatient days), standardized incidence rate 1.76, 95% CI (0.32-9.63). Despite many other epileptogenic factors, imipenem or meropenem did not increase the risk of seizures in neurosurgical patients. There was not further risk for patients with pre-existing seizures or creatinine clearance abnormalities when dosed appropriate.

  8. Postoperative Neurosurgical Infection Rates After Shared-Resource Intraoperative Magnetic Resonance Imaging: A Single-Center Experience with 195 Cases. (United States)

    Dinevski, Nikolaj; Sarnthein, Johannes; Vasella, Flavio; Fierstra, Jorn; Pangalu, Athina; Holzmann, David; Regli, Luca; Bozinov, Oliver


    To determine the rate of surgical-site infections (SSI) in neurosurgical procedures involving a shared-resource intraoperative magnetic resonance imaging (ioMRI) scanner at a single institution derived from a prospective clinical quality management database. All consecutive neurosurgical procedures that were performed with a high-field, 2-room ioMRI between April 2013 and June 2016 were included (N = 195; 109 craniotomies and 86 endoscopic transsphenoidal procedures). The incidence of SSIs within 3 months after surgery was assessed for both operative groups (craniotomies vs. transsphenoidal approach). Of the 109 craniotomies, 6 patients developed an SSI (5.5%, 95% confidence interval [CI] 1.2-9.8%), including 1 superficial SSI, 2 cases of bone flap osteitis, 1 intracranial abscess, and 2 cases of meningitis/ventriculitis. Wound revision surgery due to infection was necessary in 4 patients (4%). Of the 86 transsphenoidal skull base surgeries, 6 patients (7.0%, 95% CI 1.5-12.4%) developed an infection, including 2 non-central nervous system intranasal SSIs (3%) and 4 cases of meningitis (5%). Logistic regression analysis revealed that the likelihood of infection significantly decreased with the number of operations in the new operational setting (odds ratio 0.982, 95% CI 0.969-0.995, P = 0.008). The use of a shared-resource ioMRI in neurosurgery did not demonstrate increased rates of infection compared with the current available literature. The likelihood of infection decreased with the accumulating number of operations, underlining the importance of surgical staff training after the introduction of a shared-resource ioMRI. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Spatial analysis and modelling based on activities

    CSIR Research Space (South Africa)

    Conradie, Dirk CU


    Full Text Available (deliberative attitudes) (Pokahr, 2005). The BDI model does not cover emotional and other ‘higher’ human attitudes. KRONOS is a generic Computational Building Simulation (CBS) tool that was developed over the past three years to work on advanced... featured, stable, mature and platform independent with an easy to use C/C++ Application Program Interface (API). It has advanced joint types and integrated collision detection with friction. ODE is particularly useful for simulating vehicles, objects...

  10. Model based control of refrigeration systems

    Energy Technology Data Exchange (ETDEWEB)

    Sloth Larsen, L.F.


    The subject for this Ph.D. thesis is model based control of refrigeration systems. Model based control covers a variety of different types of controls, that incorporates mathematical models. In this thesis the main subject therefore has been restricted to deal with system optimizing control. The optimizing control is divided into two layers, where the system oriented top layers deals with set-point optimizing control and the lower layer deals with dynamical optimizing control in the subsystems. The thesis has two main contributions, i.e. a novel approach for set-point optimization and a novel approach for desynchronization based on dynamical optimization. The focus in the development of the proposed set-point optimizing control has been on deriving a simple and general method, that with ease can be applied on various compositions of the same class of systems, such as refrigeration systems. The method is based on a set of parameter depended static equations describing the considered process. By adapting the parameters to the given process, predict the steady state and computing a steady state gradient of the cost function, the process can be driven continuously towards zero gradient, i.e. the optimum (if the cost function is convex). The method furthermore deals with system constrains by introducing barrier functions, hereby the best possible performance taking the given constrains in to account can be obtained, e.g. under extreme operational conditions. The proposed method has been applied on a test refrigeration system, placed at Aalborg University, for minimization of the energy consumption. Here it was proved that by using general static parameter depended system equations it was possible drive the set-points close to the optimum and thus reduce the power consumption with up to 20%. In the dynamical optimizing layer the idea is to optimize the operation of the subsystem or the groupings of subsystems, that limits the obtainable system performance. In systems

  11. Model Based Autonomy for Robust Mars Operations (United States)

    Kurien, James A.; Nayak, P. Pandurang; Williams, Brian C.; Lau, Sonie (Technical Monitor)


    Space missions have historically relied upon a large ground staff, numbering in the hundreds for complex missions, to maintain routine operations. When an anomaly occurs, this small army of engineers attempts to identify and work around the problem. A piloted Mars mission, with its multiyear duration, cost pressures, half-hour communication delays and two-week blackouts cannot be closely controlled by a battalion of engineers on Earth. Flight crew involvement in routine system operations must also be minimized to maximize science return. It also may be unrealistic to require the crew have the expertise in each mission subsystem needed to diagnose a system failure and effect a timely repair, as engineers did for Apollo 13. Enter model-based autonomy, which allows complex systems to autonomously maintain operation despite failures or anomalous conditions, contributing to safe, robust, and minimally supervised operation of spacecraft, life support, In Situ Resource Utilization (ISRU) and power systems. Autonomous reasoning is central to the approach. A reasoning algorithm uses a logical or mathematical model of a system to infer how to operate the system, diagnose failures and generate appropriate behavior to repair or reconfigure the system in response. The 'plug and play' nature of the models enables low cost development of autonomy for multiple platforms. Declarative, reusable models capture relevant aspects of the behavior of simple devices (e.g. valves or thrusters). Reasoning algorithms combine device models to create a model of the system-wide interactions and behavior of a complex, unique artifact such as a spacecraft. Rather than requiring engineers to all possible interactions and failures at design time or perform analysis during the mission, the reasoning engine generates the appropriate response to the current situation, taking into account its system-wide knowledge, the current state, and even sensor failures or unexpected behavior.

  12. A Requirements Analysis Model Based on QFD

    Institute of Scientific and Technical Information of China (English)

    TANG Zhi-wei; Nelson K.H.Tang


    The enterprise resource planning (ERP) system has emerged to offer an integrated IT solution and more and more enterprises are increasing by adopting this system and regarding it as an important innovation. However, there is already evidence of high failure risks in ERP project implementation, one major reason is poor analysis of the requirements for system implementation. In this paper, the importance of requirements analysis for ERP project implementation is highlighted, and a requirements analysis model by applying quality function deployment (QFD) is presented, which will support to conduct requirements analysis for ERP project.

  13. Model-Based Systems Engineering in Concurrent Engineering Centers (United States)

    Iwata, Curtis; Infeld, Samantha; Bracken, Jennifer Medlin; McGuire, Melissa; McQuirk, Christina; Kisdi, Aron; Murphy, Jonathan; Cole, Bjorn; Zarifian, Pezhman


    Concurrent Engineering Centers (CECs) are specialized facilities with a goal of generating and maturing engineering designs by enabling rapid design iterations. This is accomplished by co-locating a team of experts (either physically or virtually) in a room with a narrow design goal and a limited timeline of a week or less. The systems engineer uses a model of the system to capture the relevant interfaces and manage the overall architecture. A single model that integrates other design information and modeling allows the entire team to visualize the concurrent activity and identify conflicts more efficiently, potentially resulting in a systems model that will continue to be used throughout the project lifecycle. Performing systems engineering using such a system model is the definition of model-based systems engineering (MBSE); therefore, CECs evolving their approach to incorporate advances in MBSE are more successful in reducing time and cost needed to meet study goals. This paper surveys space mission CECs that are in the middle of this evolution, and the authors share their experiences in order to promote discussion within the community.

  14. Model-based accelerator controls: What, why and how

    International Nuclear Information System (INIS)

    Sidhu, S.S.


    Model-based control is defined as a gamut of techniques whose aim is to improve the reliability of an accelerator and enhance the capabilities of the operator, and therefore of the whole control system. The aim of model-based control is seen as gradually moving the function of model-reference from the operator to the computer. The role of the operator in accelerator control and the need for and application of model-based control are briefly summarized

  15. Model-based setup assistant for progressive tools (United States)

    Springer, Robert; Gräler, Manuel; Homberg, Werner; Henke, Christian; Trächtler, Ansgar


    In the field of production systems, globalization and technological progress lead to increasing requirements regarding part quality, delivery time and costs. Hence, today's production is challenged much more than a few years ago: it has to be very flexible and produce economically small batch sizes to satisfy consumer's demands and avoid unnecessary stock. Furthermore, a trend towards increasing functional integration continues to lead to an ongoing miniaturization of sheet metal components. In the industry of electric connectivity for example, the miniaturized connectors are manufactured by progressive tools, which are usually used for very large batches. These tools are installed in mechanical presses and then set up by a technician, who has to manually adjust a wide range of punch-bending operations. Disturbances like material thickness, temperatures, lubrication or tool wear complicate the setup procedure. In prospect of the increasing demand of production flexibility, this time-consuming process has to be handled more and more often. In this paper, a new approach for a model-based setup assistant is proposed as a solution, which is exemplarily applied in combination with a progressive tool. First, progressive tools, more specifically, their setup process is described and based on that, the challenges are pointed out. As a result, a systematic process to set up the machines is introduced. Following, the process is investigated with an FE-Analysis regarding the effects of the disturbances. In the next step, design of experiments is used to systematically develop a regression model of the system's behaviour. This model is integrated within an optimization in order to calculate optimal machine parameters and the following necessary adjustment of the progressive tool due to the disturbances. Finally, the assistant is tested in a production environment and the results are discussed.

  16. Save the patient a trip. Outcome difference between conservatively treated patients with traumatic brain injury in a nonspecialized intensive care unit vs a specialized neurosurgical intensive care unit in the Sultanate of Oman. (United States)

    Al-Kashmiri, Ammar M; Al-Shaqsi, Sultan Z; Al-Kharusi, Adil S; Al-Tamimi, Laila A


    Traumatic brain injury (TBI) continues to be the main cause of death among trauma patients. Accurate diagnosis and timely surgical interventions are critical steps in reducing the mortality from this disease. For patients who have no surgically reversible head injury pathology, the decision to transfer to a dedicated neurosurgical unit is usually controversial. To compare the outcome of patients with severe TBI treated conservatively in a specialized neurosurgical intensive care unit (ICU) and those treated conservatively at a general ICU in the Sultanate of Oman. Retrospective cohort study. This is a retrospective study of patients with severe TBI admitted to Khoula Hospital ICU (specialized neurosurgical ICU) and Nizwa Hospital ICU (general ICU) in Oman in 2013. Surgically treated patients were excluded. Data extracted included demographics, injury details, interventions, and outcomes. The outcome variables included mortality, length of stay, length of ICU days, and ventilated days. There were 100 patients with severe TBI treated conservatively at Khoula Hospital compared with 74 patients at Nizwa Hospital. Basic demographics were similar between the 2 groups. No significant difference was found in mortality, length of stay, ICU days, and ventilation days. There is no difference in outcome between patients with TBI treated conservatively in a specialized neurosurgical ICU and those treated in a general nonspecialized ICU in Oman in 2013. Therefore, unless neurosurgical intervention is warranted or expected, patients with TBI may be managed in a general ICU, saving the risk and expense of a transfer to a specialized neurosurgical ICU. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Has the impact of the working time regulations changed neurosurgical trainees' attitudes towards the European working time directive 5 years on? (United States)

    Cowie, Christopher J A; Pešić-Smith, Jonathan D; Boukas, Alexandros; Nelson, Richard J


    We report the results from a survey of the British Neurosurgical Trainees' Association which aimed to assess current rota patterns and their compliance with the government's working time regulations. The survey questioned whether trainees felt that shift working, imposed as a result of the European working time directive, is continuing to impact on patient care and training opportunities in neurosurgery. The responses to this survey indicate that neurosurgical trainees remain concerned with the impact that the current working time regulations have on all facets of their work: training, work- life balance, and the provision of patient care. The survey comments show that the majority would support a change in legislation to allow greater flexibility in the working time regulations.

  18. Accelerating progress on the road to safer sports: based on remarks of NFL Commissioner Roger Goodell in the Neurosurgical Society of America (NSA) medal lecture. (United States)

    Goodell, Roger; Batjer, H Hunt; Ellenbogen, Richard G


    Roger Goodell was invited by the Neurosurgical Society of America (NSA) to give the keynote speech as the NSA Medalist 2013. As President of the NSA, and Co-Chairs of the National Football league's Head Neck and Spine Committee, we provided the introduction for Goodell. He was cited for his tireless advocacy on behalf of professional and student athletes. We noted that the National Football League has been a world leader in funding traumatic brain injury research and a catalyst for safety in youth and professional sports. Mr Goodell's national leadership in thinking and acting boldly on the subject of traumatic brain injury prevention and treatment was the primary motivation for awarding him the NSA medal. What follows is a transcript of his NSA Medal Lecture to the Neurosurgical Society of America.

  19. Application of an aviation model of incident reporting and investigation to the neurosurgical scenario: method and preliminary data. (United States)

    Ferroli, Paolo; Caldiroli, Dario; Acerbi, Francesco; Scholtze, Maurizio; Piro, Alfonso; Schiariti, Marco; Orena, Eleonora F; Castiglione, Melina; Broggi, Morgan; Perin, Alessandro; DiMeco, Francesco


    Incident reporting systems are universally recognized as important tools for quality improvement in all complex adaptive systems, including the operating room. Nevertheless, introducing a safety culture among neurosurgeons is a slow process, and few studies are available in the literature regarding the implementation of an incident reporting system within a neurosurgical department. The authors describe the institution of an aviation model of incident reporting and investigation in neurosurgery, focusing on the method they have used and presenting some preliminary results. In 2010, the Inpatient Safety On-Board project was developed through cooperation between a team of human factor and safety specialists with aviation backgrounds (DgSky team) and the general manager of the Fondazione Istituto Neurologico Carlo Besta. In 2011, after specific training in safety culture, the authors implemented an aviation-derived prototype of incident reporting within the Department of Neurosurgery. They then developed an experimental protocol to track, analyze, and categorize any near misses that happened in the operating room. This project officially started in January 2012, when a dedicated team of assessors was established. All members of the neurosurgical department were asked to report near misses on a voluntary, confidential, and protected form (Patient Incident Reporting System form, Besta Safety Management Programme). Reports were entered into an online database and analyzed by a dedicated team of assessors with the help of a facilitator, and an aviation-derived root cause analysis was performed. Since January 2012, 14 near misses were analyzed and classified. The near-miss contributing factors were mainly related to human factors (9 of 14 cases), technology (1 of 14 cases), organizational factors (3 of 14 cases), or procedural factors (1 of 14 cases). Implementing an incident reporting system is quite demanding; the process should involve all of the people who work within

  20. Model-based cartilage thickness measurement in the submillimeter range

    International Nuclear Information System (INIS)

    Streekstra, G. J.; Strackee, S. D.; Maas, M.; Wee, R. ter; Venema, H. W.


    Current methods of image-based thickness measurement in thin sheet structures utilize second derivative zero crossings to locate the layer boundaries. It is generally acknowledged that the nonzero width of the point spread function (PSF) limits the accuracy of this measurement procedure. We propose a model-based method that strongly reduces PSF-induced bias by incorporating the PSF into the thickness estimation method. We estimated the bias in thickness measurements in simulated thin sheet images as obtained from second derivative zero crossings. To gain insight into the range of sheet thickness where our method is expected to yield improved results, sheet thickness was varied between 0.15 and 1.2 mm with an assumed PSF as present in the high-resolution modes of current computed tomography (CT) scanners [full width at half maximum (FWHM) 0.5-0.8 mm]. Our model-based method was evaluated in practice by measuring layer thickness from CT images of a phantom mimicking two parallel cartilage layers in an arthrography procedure. CT arthrography images of cadaver wrists were also evaluated, and thickness estimates were compared to those obtained from high-resolution anatomical sections that served as a reference. The thickness estimates from the simulated images reveal that the method based on second derivative zero crossings shows considerable bias for layers in the submillimeter range. This bias is negligible for sheet thickness larger than 1 mm, where the size of the sheet is more than twice the FWHM of the PSF but can be as large as 0.2 mm for a 0.5 mm sheet. The results of the phantom experiments show that the bias is effectively reduced by our method. The deviations from the true thickness, due to random fluctuations induced by quantum noise in the CT images, are of the order of 3% for a standard wrist imaging protocol. In the wrist the submillimeter thickness estimates from the CT arthrography images correspond within 10% to those estimated from the anatomical

  1. Standardized Application of Laxatives and Physical Measures in Neurosurgical Intensive Care Patients Improves Defecation Pattern but Is Not Associated with Lower Intracranial Pressure

    Directory of Open Access Journals (Sweden)

    Martin Kieninger


    Full Text Available Background. Inadequate bowel movements might be associated with an increase in intracranial pressure in neurosurgical patients. In this study we investigated the influence of a structured application of laxatives and physical measures following a strict standard operating procedure (SOP on bowel movement, intracranial pressure (ICP, and length of hospital stay in patients with a serious acute cerebral disorder. Methods. After the implementation of the SOP patients suffering from a neurosurgical disorder received pharmacological and nonpharmacological measures to improve bowel movements in a standardized manner within the first 5 days after admission to the intensive care unit (ICU starting on day of admission. We compared mean ICP levels, length of ICU stay, and mechanical ventilation to a historical control group. Results. Patients of the intervention group showed an adequate defecation pattern significantly more often than the patients of the control group. However, this was not associated with lower ICP values, fewer days of mechanical ventilation, or earlier discharge from ICU. Conclusions. The implementation of a SOP for bowel movement increases the frequency of adequate bowel movements in neurosurgical critical care patients. However, this seems not to be associated with reduced ICP values.

  2. Standardized application of laxatives and physical measures in neurosurgical intensive care patients improves defecation pattern but is not associated with lower intracranial pressure. (United States)

    Kieninger, Martin; Sinner, Barbara; Graf, Bernhard; Grassold, Astrid; Bele, Sylvia; Seemann, Milena; Künzig, Holger; Zech, Nina


    Background. Inadequate bowel movements might be associated with an increase in intracranial pressure in neurosurgical patients. In this study we investigated the influence of a structured application of laxatives and physical measures following a strict standard operating procedure (SOP) on bowel movement, intracranial pressure (ICP), and length of hospital stay in patients with a serious acute cerebral disorder. Methods. After the implementation of the SOP patients suffering from a neurosurgical disorder received pharmacological and nonpharmacological measures to improve bowel movements in a standardized manner within the first 5 days after admission to the intensive care unit (ICU) starting on day of admission. We compared mean ICP levels, length of ICU stay, and mechanical ventilation to a historical control group. Results. Patients of the intervention group showed an adequate defecation pattern significantly more often than the patients of the control group. However, this was not associated with lower ICP values, fewer days of mechanical ventilation, or earlier discharge from ICU. Conclusions. The implementation of a SOP for bowel movement increases the frequency of adequate bowel movements in neurosurgical critical care patients. However, this seems not to be associated with reduced ICP values.

  3. A Time-Series Water Level Forecasting Model Based on Imputation and Variable Selection Method


    Jun-He Yang; Ching-Hsue Cheng; Chia-Pan Chan


    Reservoirs are important for households and impact the national economy. This paper proposed a time-series forecasting model based on estimating a missing value followed by variable selection to forecast the reservoir's water level. This study collected data from the Taiwan Shimen Reservoir as well as daily atmospheric data from 2008 to 2015. The two datasets are concatenated into an integrated dataset based on ordering of the data as a research dataset. The proposed time-series forecasting m...

  4. Stochastic Interest Model Based on Compound Poisson Process and Applications in Actuarial Science


    Li, Shilong; Yin, Chuancun; Zhao, Xia; Dai, Hongshuai


    Considering stochastic behavior of interest rates in financial market, we construct a new class of interest models based on compound Poisson process. Different from the references, this paper describes the randomness of interest rates by modeling the force of interest with Poisson random jumps directly. To solve the problem in calculation of accumulated interest force function, one important integral technique is employed. And a conception called the critical value is introduced to investigat...

  5. Model based design of electronic throttle control (United States)

    Cherian, Fenin; Ranjan, Ashish; Bhowmick, Pathikrit; Rammohan, A.


    With the advent of torque based Engine Management Systems, the precise control and robust performance of the throttle body becomes a key factor in the overall performance of the vehicle. Electronic Throttle Control provides benefits such as improved air-fuel ratio for improving the vehicle performance and lower exhausts emissions to meet the stringent emission norms. Modern vehicles facilitate various features such as Cruise Control, Traction Control, Electronic Stability Program and Pre-crash systems. These systems require control over engine power without driver intervention, which is not possible with conventional mechanical throttle system. Thus these systems are integrated to function with the electronic throttle control. However, due to inherent non-linearities in the throttle body, the control becomes a difficult task. In order to eliminate the influence of this hysteresis at the initial operation of the butterfly valve, a control to compensate the shortage must be added to the duty required for starting throttle operation when the initial operation is detected. Therefore, a lot of work is being done in this field to incorporate the various nonlinearities to achieve robust control. In our present work, the ETB was tested to verify the working of the system. Calibration of the TPS sensors was carried out in order to acquire accurate throttle opening angle. The response of the calibrated system was then plotted against a step input signal. A linear model of the ETB was prepared using Simulink and its response was compared with the experimental data to find out the initial deviation of the model from the actual system. To reduce this deviation, non-linearities from existing literature were introduced to the system and a response analysis was performed to check the deviation from the actual system. Based on this investigation, an introduction of a new nonlinearity parameter can be used in future to reduce the deviation further making the control of the ETB more

  6. Enabling Accessibility Through Model-Based User Interface Development. (United States)

    Ziegler, Daniel; Peissner, Matthias


    Adaptive user interfaces (AUIs) can increase the accessibility of interactive systems. They provide personalized display and interaction modes to fit individual user needs. Most AUI approaches rely on model-based development, which is considered relatively demanding. This paper explores strategies to make model-based development more attractive for mainstream developers.

  7. Model-Based Software Testing for Object-Oriented Software (United States)

    Biju, Soly Mathew


    Model-based testing is one of the best solutions for testing object-oriented software. It has a better test coverage than other testing styles. Model-based testing takes into consideration behavioural aspects of a class, which are usually unchecked in other testing methods. An increase in the complexity of software has forced the software industry…

  8. Towards automatic model based controller design for reconfigurable plants

    DEFF Research Database (Denmark)

    Michelsen, Axel Gottlieb; Stoustrup, Jakob; Izadi-Zamanabadi, Roozbeh


    This paper introduces model-based Plug and Play Process Control, a novel concept for process control, which allows a model-based control system to be reconfigured when a sensor or an actuator is plugged into a controlled process. The work reported in this paper focuses on composing a monolithic m...

  9. Model based design introduction: modeling game controllers to microprocessor architectures (United States)

    Jungwirth, Patrick; Badawy, Abdel-Hameed


    We present an introduction to model based design. Model based design is a visual representation, generally a block diagram, to model and incrementally develop a complex system. Model based design is a commonly used design methodology for digital signal processing, control systems, and embedded systems. Model based design's philosophy is: to solve a problem - a step at a time. The approach can be compared to a series of steps to converge to a solution. A block diagram simulation tool allows a design to be simulated with real world measurement data. For example, if an analog control system is being upgraded to a digital control system, the analog sensor input signals can be recorded. The digital control algorithm can be simulated with the real world sensor data. The output from the simulated digital control system can then be compared to the old analog based control system. Model based design can compared to Agile software develop. The Agile software development goal is to develop working software in incremental steps. Progress is measured in completed and tested code units. Progress is measured in model based design by completed and tested blocks. We present a concept for a video game controller and then use model based design to iterate the design towards a working system. We will also describe a model based design effort to develop an OS Friendly Microprocessor Architecture based on the RISC-V.

  10. Learning of Chemical Equilibrium through Modelling-Based Teaching (United States)

    Maia, Poliana Flavia; Justi, Rosaria


    This paper presents and discusses students' learning process of chemical equilibrium from a modelling-based approach developed from the use of the "Model of Modelling" diagram. The investigation was conducted in a regular classroom (students 14-15 years old) and aimed at discussing how modelling-based teaching can contribute to students…

  11. Using 3D Printing to Create Personalized Brain Models for Neurosurgical Training and Preoperative Planning. (United States)

    Ploch, Caitlin C; Mansi, Chris S S A; Jayamohan, Jayaratnam; Kuhl, Ellen


    Three-dimensional (3D) printing holds promise for a wide variety of biomedical applications, from surgical planning, practicing, and teaching to creating implantable devices. The growth of this cheap and easy additive manufacturing technology in orthopedic, plastic, and vascular surgery has been explosive; however, its potential in the field of neurosurgery remains underexplored. A major limitation is that current technologies are unable to directly print ultrasoft materials like human brain tissue. In this technical note, the authors present a new technology to create deformable, personalized models of the human brain. The method combines 3D printing, molding, and casting to create a physiologically, anatomically, and tactilely realistic model based on magnetic resonance images. Created from soft gelatin, the model is easy to produce, cost-efficient, durable, and orders of magnitude softer than conventionally printed 3D models. The personalized brain model cost $50, and its fabrication took 24 hours. In mechanical tests, the model stiffness (E = 25.29 ± 2.68 kPa) was 5 orders of magnitude softer than common 3D printed materials, and less than an order of magnitude stiffer than mammalian brain tissue (E = 2.64 ± 0.40 kPa). In a multicenter surgical survey, model size (100.00%), visual appearance (83.33%), and surgical anatomy (81.25%) were perceived as very realistic. The model was perceived as very useful for patient illustration (85.00%), teaching (94.44%), learning (100.00%), surgical training (95.00%), and preoperative planning (95.00%). With minor refinements, personalized, deformable brain models created via 3D printing will improve surgical training and preoperative planning with the ultimate goal to provide accurate, customized, high-precision treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Mechanics and model-based control of advanced engineering systems

    CERN Document Server

    Irschik, Hans; Krommer, Michael


    Mechanics and Model-Based Control of Advanced Engineering Systems collects 32 contributions presented at the International Workshop on Advanced Dynamics and Model Based Control of Structures and Machines, which took place in St. Petersburg, Russia in July 2012. The workshop continued a series of international workshops, which started with a Japan-Austria Joint Workshop on Mechanics and Model Based Control of Smart Materials and Structures and a Russia-Austria Joint Workshop on Advanced Dynamics and Model Based Control of Structures and Machines. In the present volume, 10 full-length papers based on presentations from Russia, 9 from Austria, 8 from Japan, 3 from Italy, one from Germany and one from Taiwan are included, which represent the state of the art in the field of mechanics and model based control, with particular emphasis on the application of advanced structures and machines.

  13. Targeted neurosurgical outreach: 5-year follow-up of operative skill transfer and sustainable care in Lima, Peru. (United States)

    Duenas, Vincent J; Hahn, Edward J; Aryan, Henry E; Levy, Michael V; Jandial, Rahul


    This study evaluates the efficacy of operative skill transfer in the context of targeted pediatric outreach missions. In addition, the ability to implement surgical care improvements that are sustainable is investigated. Three 1-week targeted neurosurgical missions were performed (2004-2006) to teach neuroendoscopy, which included donation of the necessary equipment so newly acquired surgical skills could be performed by local neurosurgeons in between and after the departure of the mission team. After the targeted missions were completed, 5 years of neuroendoscopy case follow-up data were obtained. After performing pediatric neurosurgery missions in 2004-2006, with a focus on teaching neuroendoscopy, the host team demonstrated the sustainability of our didactic efforts in the subsequent 5 years by performing cases independently for their citizens. To date, a total of 196 operations have been performed in the past 5 years independent of any visiting team. Effective operative skill transfer to host neurosurgeons can be accomplished with limited international team visits utilizing a targeted approach that minimizes expenditures on personnel and capital. With the priority being teaching of an operative technique, as opposed to perennially performing operations by the mission team, sustainable surgical care was achieved after missions officially concluded.

  14. Simple Improvisation to Enhance Utility of Fluorescein Sodium in Resection of Intracranial Lesions at Routine Neurosurgical Centers. (United States)

    Gollapudi, Prakash Rao; Mohammed, Imran; Pittala, Sandeep R; Kotha, Arjun Reddy; Reddycherla, Naga Raju; Ginjupally, Dhanunjaya Rao


    Fluorescein sodium is one of the fluorophores that is used in the resection of intracranial lesions. It is commonly used along with a customized microscope, which is expensive and not available universally. In this study, we describe a simple, inexpensive method for better visualization of intracranial and spinal cord lesions with fluorescein. After a test dose, 20 mg/kg of fluorescein sodium was administered intravenously at the time of intubation. A blue light source was used before resection for precise localization of the intracranial lesions after durotomy. Most of the resection was done under the white light, while the blue light was used intermittently to delineate the pathologic tissue from the normal tissue and to ensure safe maximal resection. The intensity of fluorescein staining under white light and blue light was noted. The study comprised 40 cases of gliomas, meningiomas, abscesses, spinal cord tumors, and cerebellopontine angle lesions. Thirty-five lesions showed good fluorescence under the blue light, which helped us achieve better resection of the pathologic lesions. Fluorescein sodium is a safe dye; it can be used to aid in precise localization and safe maximal resection of the pathologic tissue with the help of a blue light source at any center with challenged resources. The blue light enhances the fluorescence and visualization of the pathologic tissue, and this technique can be adopted by any surgeon without much difficulty even with a basic neurosurgical setup. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Assistance to neurosurgical planning: using a fuzzy spatial graph model of the brain for locating anatomical targets in MRI (United States)

    Villéger, Alice; Ouchchane, Lemlih; Lemaire, Jean-Jacques; Boire, Jean-Yves


    Symptoms of neurodegenerative pathologies such as Parkinson's disease can be relieved through Deep Brain Stimulation. This neurosurgical technique relies on high precision positioning of electrodes in specific areas of the basal ganglia and the thalamus. These subcortical anatomical targets must be located at pre-operative stage, from a set of MRI acquired under stereotactic conditions. In order to assist surgical planning, we designed a semi-automated image analysis process for extracting anatomical areas of interest. Complementary information, provided by both patient's data and expert knowledge, is represented as fuzzy membership maps, which are then fused by means of suitable possibilistic operators in order to achieve the segmentation of targets. More specifically, theoretical prior knowledge on brain anatomy is modelled within a 'virtual atlas' organised as a spatial graph: a list of vertices linked by edges, where each vertex represents an anatomical structure of interest and contains relevant information such as tissue composition, whereas each edge represents a spatial relationship between two structures, such as their relative directions. The model is built using heterogeneous sources of information such as qualitative descriptions from the expert, or quantitative information from prelabelled images. For each patient, tissue membership maps are extracted from MR data through a classification step. Prior model and patient's data are then matched by using a research algorithm (or 'strategy') which simultaneously computes an estimation of the location of every structures. The method was tested on 10 clinical images, with promising results. Location and segmentation results were statistically assessed, opening perspectives for enhancements.

  16. A new head-mounted display-based augmented reality system in neurosurgical oncology: a study on phantom. (United States)

    Cutolo, Fabrizio; Meola, Antonio; Carbone, Marina; Sinceri, Sara; Cagnazzo, Federico; Denaro, Ennio; Esposito, Nicola; Ferrari, Mauro; Ferrari, Vincenzo


    Benefits of minimally invasive neurosurgery mandate the development of ergonomic paradigms for neuronavigation. Augmented Reality (AR) systems can overcome the shortcomings of commercial neuronavigators. The aim of this work is to apply a novel AR system, based on a head-mounted stereoscopic video see-through display, as an aid in complex neurological lesion targeting. Effectiveness was investigated on a newly designed patient-specific head mannequin featuring an anatomically realistic brain phantom with embedded synthetically created tumors and eloquent areas. A two-phase evaluation process was adopted in a simulated small tumor resection adjacent to Broca's area. Phase I involved nine subjects without neurosurgical training in performing spatial judgment tasks. In Phase II, three surgeons were involved in assessing the effectiveness of the AR-neuronavigator in performing brain tumor targeting on a patient-specific head phantom. Phase I revealed the ability of the AR scene to evoke depth perception under different visualization modalities. Phase II confirmed the potentialities of the AR-neuronavigator in aiding the determination of the optimal surgical access to the surgical target. The AR-neuronavigator is intuitive, easy-to-use, and provides three-dimensional augmented information in a perceptually-correct way. The system proved to be effective in guiding skin incision, craniotomy, and lesion targeting. The preliminary results encourage a structured study to prove clinical effectiveness. Moreover, our testing platform might be used to facilitate training in brain tumour resection procedures.

  17. The Importance of Perioperative Prophylaxis with Cefuroxime or Ceftriaxone in the Surgical Site Infections Prevention after Cranial and Spinal Neurosurgical Procedures. (United States)

    Dimovska-Gavrilovska, Aleksandra; Chaparoski, Aleksandar; Gavrilovski, Andreja; Milenkovikj, Zvonko


    Introduction Surgical site infections pose a significant problem in the treatment of neurosurgical procedures, regardless of the application of perioperative prophylaxis with systemic antibiotics. The infection rate in these procedures ranges from less than 1% to above 15%. Different antibiotics and administration regimes have been used in the perioperative prophylaxis so far, and there are numerous comparative studies regarding their efficiency, however, it is generally indicated that the choice thereof should be based on information and local specifics connected to the most probable bacterial causers, which would possibly contaminate the surgical site and cause infection, and moreover, the mandatory compliance with the principles of providing adequate concentration of the drug at the time of the anticipated contamination. Objective Comparing the protective effect of two perioperative prophylactic antibiotic regimes using cefuroxime (second generation cephalosporin) and ceftriaxone (third generation cephalosporin) in the prevention of postoperative surgical site infections after elective and urgent cranial and spinal neurosurgical procedures at the University Clinic for Neurosurgery in Skopje in the period of the first three months of 2016. Design of the study Prospective randomized comparative study. Outcome measures Establishing the clinical outcome represented as prevalence of superficial and deep incision and organ/space postoperative surgical site infections. Material and method We analyzed prospectively 40 patients who received parenteral antibiotic prophylaxis with two antibiotic regimes one hour before the routine neurosurgical cranial and spinal surgical procedures; the patients were randomized in two groups, according to the order of admission and participation in the study, alternately, non-selectively, those persons who fulfilled inclusion criteria were placed in one of the two programmed regimes with cefuroxime in the first, and cefotaxime in the

  18. Adaptive surrogate model based multiobjective optimization for coastal aquifer management (United States)

    Song, Jian; Yang, Yun; Wu, Jianfeng; Wu, Jichun; Sun, Xiaomin; Lin, Jin


    In this study, a novel surrogate model assisted multiobjective memetic algorithm (SMOMA) is developed for optimal pumping strategies of large-scale coastal groundwater problems. The proposed SMOMA integrates an efficient data-driven surrogate model with an improved non-dominated sorted genetic algorithm-II (NSGAII) that employs a local search operator to accelerate its convergence in optimization. The surrogate model based on Kernel Extreme Learning Machine (KELM) is developed and evaluated as an approximate simulator to generate the patterns of regional groundwater flow and salinity levels in coastal aquifers for reducing huge computational burden. The KELM model is adaptively trained during evolutionary search to satisfy desired fidelity level of surrogate so that it inhibits error accumulation of forecasting and results in correctly converging to true Pareto-optimal front. The proposed methodology is then applied to a large-scale coastal aquifer management in Baldwin County, Alabama. Objectives of minimizing the saltwater mass increase and maximizing the total pumping rate in the coastal aquifers are considered. The optimal solutions achieved by the proposed adaptive surrogate model are compared against those solutions obtained from one-shot surrogate model and original simulation model. The adaptive surrogate model does not only improve the prediction accuracy of Pareto-optimal solutions compared with those by the one-shot surrogate model, but also maintains the equivalent quality of Pareto-optimal solutions compared with those by NSGAII coupled with original simulation model, while retaining the advantage of surrogate models in reducing computational burden up to 94% of time-saving. This study shows that the proposed methodology is a computationally efficient and promising tool for multiobjective optimizations of coastal aquifer managements.

  19. Comparison between two photovoltaic module models based on transistors (United States)

    Saint-Eve, Frédéric; Sawicki, Jean-Paul; Petit, Pierre; Maufay, Fabrice; Aillerie, Michel


    The main objective of this paper is to verify the possibility to reduce to a simple electronic circuit with very few components the behavior simulation of an un-shaded photovoltaic (PV) module. Particularly, two models based on well-tried elementary structures, i.e., the Darlington structure in first model and the voltage regulation with programmable Zener diode in the second are analyzed. Specifications extracted from the behavior of a real I-V characteristic of a panel are considered and the principal electrical variables are deduced. The two models are expected to match with open circuit voltage, maximum power point (MPP) and short circuit current, without forgetting realistic current slopes on the both sides of MPP. The robustness is mentioned when irradiance varies and is considered as an additional fundamental property. For both models, two simulations are done to identify influence of some parameters. In the first model, a parameter allowing to adjust current slope on left side of MPP proves to be also important for the calculation of open circuit voltage. Besides this model does not authorize an entirely adjustment of I-V characteristic and MPP moves significantly away from real value when irradiance increases. On the contrary, the second model seems to have only qualities: open circuit voltage is easy to calculate, current slopes are realistic and there is perhaps a good robustness when irradiance variations are simulated by adjusting short circuit current of PV module. We have shown that these two simplified models are expected to make reliable and easier simulations of complex PV architecture integrating many different devices like PV modules or other renewable energy sources and storage capacities coupled in parallel association.

  20. Model-Based Reasoning in Humans Becomes Automatic with Training.

    Directory of Open Access Journals (Sweden)

    Marcos Economides


    Full Text Available Model-based and model-free reinforcement learning (RL have been suggested as algorithmic realizations of goal-directed and habitual action strategies. Model-based RL is more flexible than model-free but requires sophisticated calculations using a learnt model of the world. This has led model-based RL to be identified with slow, deliberative processing, and model-free RL with fast, automatic processing. In support of this distinction, it has recently been shown that model-based reasoning is impaired by placing subjects under cognitive load--a hallmark of non-automaticity. Here, using the same task, we show that cognitive load does not impair model-based reasoning if subjects receive prior training on the task. This finding is replicated across two studies and a variety of analysis methods. Thus, task familiarity permits use of model-based reasoning in parallel with other cognitive demands. The ability to deploy model-based reasoning in an automatic, parallelizable fashion has widespread theoretical implications, particularly for the learning and execution of complex behaviors. It also suggests a range of important failure modes in psychiatric disorders.

  1. Model-Based GN and C Simulation and Flight Software Development for Orion Missions beyond LEO (United States)

    Odegard, Ryan; Milenkovic, Zoran; Henry, Joel; Buttacoli, Michael


    For Orion missions beyond low Earth orbit (LEO), the Guidance, Navigation, and Control (GN&C) system is being developed using a model-based approach for simulation and flight software. Lessons learned from the development of GN&C algorithms and flight software for the Orion Exploration Flight Test One (EFT-1) vehicle have been applied to the development of further capabilities for Orion GN&C beyond EFT-1. Continuing the use of a Model-Based Development (MBD) approach with the Matlab®/Simulink® tool suite, the process for GN&C development and analysis has been largely improved. Furthermore, a model-based simulation environment in Simulink, rather than an external C-based simulation, greatly eases the process for development of flight algorithms. The benefits seen by employing lessons learned from EFT-1 are described, as well as the approach for implementing additional MBD techniques. Also detailed are the key enablers for improvements to the MBD process, including enhanced configuration management techniques for model-based software systems, automated code and artifact generation, and automated testing and integration.

  2. A Model-based Avionic Prognostic Reasoner (MAPR) (United States)

    National Aeronautics and Space Administration — The Model-based Avionic Prognostic Reasoner (MAPR) presented in this paper is an innovative solution for non-intrusively monitoring the state of health (SoH) and...

  3. A Model-Based Prognostics Approach Applied to Pneumatic Valves (United States)

    National Aeronautics and Space Administration — Within the area of systems health management, the task of prognostics centers on predicting when components will fail. Model-based prognostics exploits domain...

  4. A Model-based Prognostics Approach Applied to Pneumatic Valves (United States)

    National Aeronautics and Space Administration — Within the area of systems health management, the task of prognostics centers on predicting when components will fail. Model-based prognostics exploits domain...

  5. Model-based Prognostics with Concurrent Damage Progression Processes (United States)

    National Aeronautics and Space Administration — Model-based prognostics approaches rely on physics-based models that describe the behavior of systems and their components. These models must account for the several...

  6. Model-based reasoning technology for the power industry

    International Nuclear Information System (INIS)

    Touchton, R.A.; Subramanyan, N.S.; Naser, J.A.


    This paper reports on model-based reasoning which refers to an expert system implementation methodology that uses a model of the system which is being reasoned about. Model-based representation and reasoning techniques offer many advantages and are highly suitable for domains where the individual components, their interconnection, and their behavior is well-known. Technology Applications, Inc. (TAI), under contract to the Electric Power Research Institute (EPRI), investigated the use of model-based reasoning in the power industry including the nuclear power industry. During this project, a model-based monitoring and diagnostic tool, called ProSys, was developed. Also, an alarm prioritization system was developed as a demonstration prototype

  7. Model-based Prognostics with Fixed-lag Particle Filters (United States)

    National Aeronautics and Space Administration — Model-based prognostics exploits domain knowl- edge of the system, its components, and how they fail by casting the underlying physical phenom- ena in a...

  8. Fuzzy model-based control of a nuclear reactor

    International Nuclear Information System (INIS)

    Van Den Durpel, L.; Ruan, D.


    The fuzzy model-based control of a nuclear power reactor is an emerging research topic world-wide. SCK-CEN is dealing with this research in a preliminary stage, including two aspects, namely fuzzy control and fuzzy modelling. The aim is to combine both methodologies in contrast to conventional model-based PID control techniques, and to state advantages of including fuzzy parameters as safety and operator feedback. This paper summarizes the general scheme of this new research project

  9. System Dynamics as Model-Based Theory Building


    Schwaninger, Markus; Grösser, Stefan N.


    This paper introduces model-based theory building as a feature of system dynamics (SD) with large potential. It presents a systemic approach to actualizing that potential, thereby opening up a new perspective on theory building in the social sciences. The question addressed is if and how SD enables the construction of high-quality theories. This contribution is based on field experiment type projects which have been focused on model-based theory building, specifically the construction of a mi...

  10. A model-based approach to estimating forest area (United States)

    Ronald E. McRoberts


    A logistic regression model based on forest inventory plot data and transformations of Landsat Thematic Mapper satellite imagery was used to predict the probability of forest for 15 study areas in Indiana, USA, and 15 in Minnesota, USA. Within each study area, model-based estimates of forest area were obtained for circular areas with radii of 5 km, 10 km, and 15 km and...

  11. Model-based Sensor Data Acquisition and Management


    Aggarwal, Charu C.; Sathe, Saket; Papaioannou, Thanasis G.; Jeung, Ho Young; Aberer, Karl


    In recent years, due to the proliferation of sensor networks, there has been a genuine need of researching techniques for sensor data acquisition and management. To this end, a large number of techniques have emerged that advocate model-based sensor data acquisition and management. These techniques use mathematical models for performing various, day-to-day tasks involved in managing sensor data. In this chapter, we survey the state-of-the-art techniques for model-based sensor data acquisition...

  12. Survey of the Knowledge of Brainstem Death and Attitude Toward Organ Donation Among Relations of Neurosurgical Patients in Nigeria. (United States)

    Rabiu, T B; Oshola, H A; Adebayo, B O


    Organ transplantation is a developing field in Nigeria, and availability of organs for donation would be a determining factor of the success of the transplant programs. Patients with brainstem death (BSD) are a major source of organs for transplantation. The level of knowledge of BSD as well as attitudes toward organ donation are very important determinants of people's willingness or otherwise to donate organs. We conducted a survey of relations of our in-service neurosurgical patients to assess their knowledge of brainstem death and attitude toward organ donation. To our knowledge, this is the first study of its kind among the growing Nigerian neurosurgery patient and patient-relations population. Convenience sampling of randomly selected relations of neurosurgical patients on admission using interviewer-administered questionnaires was performed. Demographic information and information about brainstem death, attitude toward brainstem death, knowledge of organ donation, and attitude toward organ donation were obtained. The study comprised 127 respondents with a mean age of 36 years (range, 19-72). The majority of the respondents (87, 62.4%) were Christians, 122 (96.1%) were Yorubas, and 66 (52.0%) were women. Eighty-five (66.9%) of the respondents had at least a secondary level of education, and 77 (60.6%) were of low socioeconomic status. Twenty-eight (22.2%) of the respondents had heard of brainstem death. Twenty-six (92.9%) of those who had heard of brainstem death believed that the brain could die long before life finally ceases. One hundred twenty-five (98.4%) of the respondents believed that death only occurs when both breathing and heartbeat stop, and 107 (83.6%) would agree with the physician on a diagnosis of brainstem death in the relation. Sixty-five (51.2%) would want such patients put on a ventilator, and, of these, 43 (66.2%) would want such patients on the ventilator in hope that he or she may recover. One hundred twelve (88.2%) of the relations were

  13. The Annual Trends between Neurointerventional and Neurosurgical Procedures in Korea: Analysis using HIRA Data from 2010 to 2016. (United States)

    Suh, Sang Hyun


    The purpose of this study was to evaluate the annual trend for several neurosurgical and neurointerventional procedures (NIPs) in Korea between 2010 and 2016 by using medical claim data. All data during the recent 7 years were collected from Bigdata Hub provided by the Health Insurance Review & Assessment Service (HIRA). Using several codes for medical practice, we estimated the number of in-patients for each practice and calculated the annual variation of each procedure. These data were compared between each NIP versus the equivalent surgical procedure and analyzed according to the geographic distribution and the hospital grade. During the past 7 years, the average growth rate of all stroke in-patients is 2.05%, and the number of in-patients with ischemic stroke is 5.2 times higher than those with hemorrhagic stroke. While clipping accounted for 53.7% (5,209/9,700) of total patients in 2010, 61.9% of patients (9,146/14,781) are currently undergoing coiling procedure in 2016. MT for acute ischemic stroke has grown annually by an average of 35.9% during the past 3 years. Stenting and angioplasty for carotid artery and intracranial artery showed relatively stable growth during the past 7 years. Especially, carotid artery stenting is rapidly increasing in secondary general hospitals, where more than 50% of these procedures were performed after 2014. In this study, we found that most of NIPs has increased annually over the past 7 years and that NIPs are rapidly replacing conventional surgical maneuvers in Korea.

  14. Cerebral oxygen saturation and cardiac output during anaesthesia in sitting position for neurosurgical procedures: a prospective observational study. (United States)

    Schramm, P; Tzanova, I; Hagen, F; Berres, M; Closhen, D; Pestel, G; Engelhard, K


    Neurosurgical operations in the dorsal cranium often require the patient to be positioned in a sitting position. This can be associated with decreased cardiac output and cerebral hypoperfusion, and possibly, inadequate cerebral oxygenation. In the present study, cerebral oxygen saturation was measured during neurosurgery in the sitting position and correlated with cardiac output. Perioperative cerebral oxygen saturation was measured continuously with two different monitors, INVOS ® and FORE-SIGHT ® . Cardiac output was measured at eight predefined time points using transoesophageal echocardiography. Forty patients were enrolled, but only 35 (20 female) were eventually operated on in the sitting position. At the first time point, the regional cerebral oxygen saturation measured with INVOS ® was 70 (sd 9)%; thereafter, it increased by 0.0187% min -1 (P<0.01). The cerebral tissue oxygen saturation measured with FORE-SIGHT ® started at 68 (sd 13)% and increased by 0.0142% min -1 (P<0.01). The mean arterial blood pressure did not change. Cardiac output was between 6.3 (sd 1.3) and 7.2 (1.8) litre min -1 at the predefined time points. Cardiac output, but not mean arterial blood pressure, showed a positive and significant correlation with cerebral oxygen saturation. During neurosurgery in the sitting position, the cerebral oxygen saturation slowly increases and, therefore, this position seems to be safe with regard to cerebral oxygen saturation. Cerebral oxygen saturation is stable because of constant CO and MAP, while the influence of CO on cerebral oxygen saturation seems to be more relevant. NCT01275898. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email:

  15. Student use of model-based reasoning when troubleshooting an electronic circuit (United States)

    Lewandowski, Heather; Stetzer, Mackenzie; van de Bogart, Kevin; Dounas-Frazer, Dimitri


    Troubleshooting systems is an integral part of experimental physics in both research and educational settings. Accordingly, ability to troubleshoot is an important learning goal for undergraduate physics lab courses. We investigate students' model-based reasoning on a troubleshooting task using data collected in think-aloud interviews during which pairs of students from two institutions attempted to diagnose and repair a malfunctioning circuit. Our analysis scheme was informed by the Experimental Modeling Framework, which describes physicists' use of mathematical and conceptual models when reasoning about experimental systems. We show that system and subsystem models were crucial for the evaluation of repairs to the circuit and played an important role in some troubleshooting strategies. Finally, drawing on data from interviews with electronics instructors from a broad range of institution types, we outline recommendations for model-based approaches to teaching and learning troubleshooting skills.

  16. Student use of model-based reasoning when troubleshooting an electric circuit (United States)

    Dounas-Frazer, Dimitri


    Troubleshooting systems is an integral part of experimental physics in both research and educational settings. Accordingly, ability to troubleshoot is an important learning goal for undergraduate physics lab courses. We investigate students' model-based reasoning on a troubleshooting task using data collected in think-aloud interviews during which pairs of students from two institutions attempted to diagnose and repair a malfunctioning circuit. Our analysis scheme was informed by the Experimental Modeling Framework, which describes physicists' use of mathematical and conceptual models when reasoning about experimental systems. We show that system and subsystem models were crucial for the evaluation of repairs to the circuit and played an important role in some troubleshooting strategies. Finally, drawing on data from interviews with electronics instructors from a broad range of institution types, we outline recommendations for model-based approaches to teaching and learning troubleshooting skills.

  17. Top-Down and Bottom-Up Approach for Model-Based Testing of Product Lines

    Directory of Open Access Journals (Sweden)

    Stephan Weißleder


    Full Text Available Systems tend to become more and more complex. This has a direct impact on system engineering processes. Two of the most important phases in these processes are requirements engineering and quality assurance. Two significant complexity drivers located in these phases are the growing number of product variants that have to be integrated into the requirements engineering and the ever growing effort for manual test design. There are modeling techniques to deal with both complexity drivers like, e.g., feature modeling and model-based test design. Their combination, however, has been seldom the focus of investigation. In this paper, we present two approaches to combine feature modeling and model-based testing as an efficient quality assurance technique for product lines. We present the corresponding difficulties and approaches to overcome them. All explanations are supported by an example of an online shop product line.

  18. Neurosurgical tactile discrimination training with haptic-based virtual reality simulation. (United States)

    Patel, Achal; Koshy, Nick; Ortega-Barnett, Juan; Chan, Hoi C; Kuo, Yong-Fan; Luciano, Cristian; Rizzi, Silvio; Matulyauskas, Martin; Kania, Patrick; Banerjee, Pat; Gasco, Jaime


    To determine if a computer-based simulation with haptic technology can help surgical trainees improve tactile discrimination using surgical instruments. Twenty junior medical students participated in the study and were randomized into two groups. Subjects in Group A participated in virtual simulation training using the ImmersiveTouch simulator (ImmersiveTouch, Inc., Chicago, IL, USA) that required differentiating the firmness of virtual spheres using tactile and kinesthetic sensation via haptic technology. Subjects in Group B did not undergo any training. With their visual fields obscured, subjects in both groups were then evaluated on their ability to use the suction and bipolar instruments to find six elastothane objects with areas ranging from 1.5 to 3.5 cm2 embedded in a urethane foam brain cavity model while relying on tactile and kinesthetic sensation only. A total of 73.3% of the subjects in Group A (simulation training) were able to find the brain cavity objects in comparison to 53.3% of the subjects in Group B (no training) (P  =  0.0183). There was a statistically significant difference in the total number of Group A subjects able to find smaller brain cavity objects (size ≤ 2.5 cm2) compared to that in Group B (72.5 vs. 40%, P  =  0.0032). On the other hand, no significant difference in the number of subjects able to detect larger objects (size ≧ 3 cm2) was found between Groups A and B (75 vs. 80%, P  =  0.7747). Virtual computer-based simulators with integrated haptic technology may improve tactile discrimination required for microsurgical technique.

  19. Comparison of different reconstruction algorithms for three-dimensional ultrasound imaging in a neurosurgical setting. (United States)

    Miller, D; Lippert, C; Vollmer, F; Bozinov, O; Benes, L; Schulte, D M; Sure, U


    Freehand three-dimensional ultrasound imaging (3D-US) is increasingly used in image-guided surgery. During image acquisition, a set of B-scans is acquired that is distributed in a non-parallel manner over the area of interest. Reconstructing these images into a regular array allows 3D visualization. However, the reconstruction process may introduce artefacts and may therefore reduce image quality. The aim of the study is to compare different algorithms with respect to image quality and diagnostic value for image guidance in neurosurgery. 3D-US data sets were acquired during surgery of various intracerebral lesions using an integrated ultrasound-navigation device. They were stored for post-hoc evaluation. Five different reconstruction algorithms, a standard multiplanar reconstruction with interpolation (MPR), a pixel nearest neighbour method (PNN), a voxel nearest neighbour method (VNN) and two voxel based distance-weighted algorithms (VNN2 and DW) were tested with respect to image quality and artefact formation. The capability of the algorithm to fill gaps within the sample volume was investigated and a clinical evaluation with respect to the diagnostic value of the reconstructed images was performed. MPR was significantly worse than the other algorithms in filling gaps. In an image subtraction test, VNN2 and DW reliably reconstructed images even if large amounts of data were missing. However, the quality of the reconstruction improved, if data acquisition was performed in a structured manner. When evaluating the diagnostic value of reconstructed axial, sagittal and coronal views, VNN2 and DW were judged to be significantly better than MPR and VNN. VNN2 and DW could be identified as robust algorithms that generate reconstructed US images with a high diagnostic value. These algorithms improve the utility and reliability of 3D-US imaging during intraoperative navigation. Copyright © 2012 John Wiley & Sons, Ltd.

  20. Perfusion MRI as a neurosurgical tool for improved targeting in stereotactic tumor biopsies. (United States)

    Lefranc, M; Monet, P; Desenclos, C; Peltier, J; Fichten, A; Toussaint, P; Sevestre, H; Deramond, H; Le Gars, D


    Stereotactic biopsies are subject to sampling errors (essentially due to target selection). The presence of contrast enhancement is not a reliable marker of malignancy. The goal of the present study was to determine whether perfusion-weighted imaging can improve target selection in stereotactic biopsies. We studied 21 consecutive stereotactic biopsies between June 2009 and March 2010. Perfusion-weighted magnetic resonance imaging (MRI) was integrated into our neuronavigator. Perfusion-weighted imaging was used as an adjunct to conventional MRI data for target determination. Conventional MRI alone was used to determine the trajectory. We found a linear correlation between regional cerebral blood volume (rCBV) and vessel density (number of vessels per mm(2); R = 0.64; p < 0.001). Perfusion-weighted imaging facilitated target determination in 11 cases (52.4%), all of which were histopathologically diagnosed as glial tumors. For glial tumors, which presented with contrast enhancement, perfusion-weighted imaging identified a more precisely delimited target in 9 cases, a different target in 1 case, and exactly the same target in 1 other case. In all cases, perfusion-selected sampling provided information on cellular features and tumor grading. rCBV was significantly associated with grading (p < 0.01), endothelial proliferation (p < 0.01), and vessel density (p < 0.01). For lesions with rCBV values ≤1, perfusion-weighted MRI did not help to determine the target but was useful for surgical management. For stereotactic biopsies, targeting based on perfusion-weighted imaging is a feasible method for reducing the sampling error and improving target selection in the histopathological diagnosis of tumors with high rCBVs. Copyright © 2012 S. Karger AG, Basel.

  1. Establishment of Next-Generation Neurosurgery Research and Training Laboratory with Integrated Human Performance Monitoring. (United States)

    Bernardo, Antonio


    Quality of neurosurgical care and patient outcomes are inextricably linked to surgical and technical proficiency and a thorough working knowledge of microsurgical anatomy. Neurosurgical laboratory-based cadaveric training is essential for the development and refinement of technical skills before their use on a living patient. Recent biotechnological advances including 3-dimensional (3D) microscopy and endoscopy, 3D printing, virtual reality, surgical simulation, surgical robotics, and advanced neuroimaging have proved to reduce the learning curve, improve conceptual understanding of complex anatomy, and enhance visuospatial skills in neurosurgical training. Until recently, few means have allowed surgeons to obtain integrated surgical and technological training in an operating room setting. We report on a new model, currently in use at our institution, for technologically integrated surgical training and innovation using a next-generation microneurosurgery skull base laboratory designed to recreate the setting of a working operating room. Each workstation is equipped with a 3D surgical microscope, 3D endoscope, surgical drills, operating table with a Mayfield head holder, and a complete set of microsurgical tools. The laboratory also houses a neuronavigation system, a surgical robotic, a surgical planning system, 3D visualization, virtual reality, and computerized simulation for training of surgical procedures and visuospatial skills. In addition, the laboratory is equipped with neurophysiological monitoring equipment in order to conduct research into human factors in surgery and the respective roles of workload and fatigue on surgeons' performance. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Effects of neurosurgical treatment and severity of head injury on cognitive functioning, general health and incidence of mental disorders in patients with traumatic brain injury. (United States)

    Rezaei, Sajjad; Asgari, Karim; Yousefzadeh, Shahrokh; Moosavi, Heshmat-Allah; Kazemnejad, Ehsan


    Neurosurgical treatment and the severity of head injury (HI) can have remarkable effect on patients' neuropsychiatric outcomes. This research aimed to study the effect of these factors on cognitive functioning, general health and incidence of mental disorders in patients with a traumatic brain injury (TBI). In this descriptive, longitudinal study, 206 TBI patients entered the study by consecutive sampling; they were then compared according to neurosurgery status and severity of their HI. Both groups underwent neurosurgical and psychological examinations. The mini mental state examination (MMSE) and general health questionnaire-28 items (GHQ-28) were administered to the study participants. At follow-up, four months later, the groups underwent a structured clinical interview by a psychiatrist based on the diagnostic and statistical manual of mental disorders, fourth edition (DSM-IV) diagnostic criteria regarding the presence of mental disorders. Analysis of covariance (ANCOVA) and multivariate analysis of covariance (MANCOVA) were performed and adjusted for the effect of confounding variables (age, gender, Glasgow outcome scale (GOS) , and level of education). The severity of HI had the most significant effect for the following variables; cognitive functioning and physical symptoms (P < 0.05). The effect of the neurosurgical treatment factor was not significant; however, the interaction effect of the two variables on social dysfunction, and total score of the GHQ-28 questionnaire appeared to be significant (P < 0.05). Fisher's exact test indicated that after a four month follow-up period, no significant differences were seen between the two groups (with or without neurosurgery) in the incidence of mental disorders, while χ(2) Test showed that having a more severe HI is significantly correlated with the incidence of mental disorders (P < 0.01). The implications of this study should be discussed with an emphasis on negative, effective factors on the cognitive

  3. Clinical Utility and Safety of a Model-Based Patient-Tailored Dose of Vancomycin in Neonates. (United States)

    Leroux, Stéphanie; Jacqz-Aigrain, Evelyne; Biran, Valérie; Lopez, Emmanuel; Madeleneau, Doriane; Wallon, Camille; Zana-Taïeb, Elodie; Virlouvet, Anne-Laure; Rioualen, Stéphane; Zhao, Wei


    Pharmacokinetic modeling has often been applied to evaluate vancomycin pharmacokinetics in neonates. However, clinical application of the model-based personalized vancomycin therapy is still limited. The objective of the present study was to evaluate the clinical utility and safety of a model-based patient-tailored dose of vancomycin in neonates. A model-based vancomycin dosing calculator, developed from a population pharmacokinetic study, has been integrated into the routine clinical care in 3 neonatal intensive care units (Robert Debré, Cochin Port Royal, and Clocheville hospitals) between 2012 and 2014. The target attainment rate, defined as the percentage of patients with a first therapeutic drug monitoring serum vancomycin concentration achieving the target window of 15 to 25 mg/liter, was selected as an endpoint for evaluating the clinical utility. The safety evaluation was focused on nephrotoxicity. The clinical application of the model-based patient-tailored dose of vancomycin has been demonstrated in 190 neonates. The mean (standard deviation) gestational and postnatal ages of the study population were 31.1 (4.9) weeks and 16.7 (21.7) days, respectively. The target attainment rate increased from 41% to 72% without any case of vancomycin-related nephrotoxicity. This proof-of-concept study provides evidence for integrating model-based antimicrobial therapy in neonatal routine care. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  4. [Tumors of the 4th ventricle and the craniospinal transitional zone. Review of patients of the Neurosurgical Clinic of the Department of Medicine of the Karl Marx University]. (United States)

    Niebeling, H G; Fried, H; Goldhahn, W E; Skrzypczak, J; Brachmann, J; Eichler, I


    From a total of 1,028 infratentorial tumours operated on at the Neurosurgical Hospital of the Section Medicine of the Karl-Marx University Leipzig in the last 30 years, 167 tumours in the region of the 4th ventrical have been selected. Their statistical processing was carried out with respect to specific localisation, average age, kind of tumour, sex, clinical findings, duration of case history, application of instrumental diagnostic procedures and radicality of operation, success and failure. Some fundamental conclussions are drawn. A subdivision in detail will be contained in the following articles based on this material.

  5. Risk of deep venous thrombosis in elective neurosurgical procedures: a prospective, Doppler ultrasound-based study in children 12 years of age or younger. (United States)

    Scherer, Andrea G; White, Ian K; Shaikh, Kashif A; Smith, Jodi L; Ackerman, Laurie L; Fulkerson, Daniel H


    OBJECTIVE The risk of venous thromboembolism (VTE) from deep venous thrombosis (DVT) is significant in neurosurgical patients. VTE is considered a leading cause of preventable hospital deaths and preventing DVT is a closely monitored quality metric, often tied to accreditation, hospital ratings, and reimbursement. Adult protocols include prophylaxis with anticoagulant medications. Children's hospitals may adopt adult protocols, although the incidence of DVT and the risk or efficacy of treatment is not well defined. The incidence of DVT in children is likely less than in adults, although there is very little prospectively collected information. Most consider the risk of DVT to be extremely low in children 12 years of age or younger. However, this consideration is based on tradition and retrospective reviews of trauma databases. In this study, the authors prospectively evaluated pediatric patients undergoing a variety of elective neurosurgical procedures and performed Doppler ultrasound studies before and after surgery. METHODS A total of 100 patients were prospectively enrolled in this study. All of the patients were between the ages of 1 month and 12 years and were undergoing elective neurosurgical procedures. The 91 patients who completed the protocol received a bilateral lower-extremity Doppler ultrasound examination within 48 hours prior to surgery. Patients did not receive either medical or mechanical DVT prophylaxis during or after surgery. The ultrasound examination was repeated within 72 hours after surgery. An independent, board-certified radiologist evaluated all sonograms. We prospectively collected data, including potential risk factors, details of surgery, and details of the clinical course. All patients were followed clinically for at least 1 year. RESULTS There was no clinical or ultrasound evidence of DVT or VTE in any of the 91 patients. There was no clinical evidence of VTE in the 9 patients who did not complete the protocol. CONCLUSIONS In this

  6. Model-based PEEP optimisation in mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Chiew Yeong Shiong


    Full Text Available Abstract Background Acute Respiratory Distress Syndrome (ARDS patients require mechanical ventilation (MV for breathing support. Patient-specific PEEP is encouraged for treating different patients but there is no well established method in optimal PEEP selection. Methods A study of 10 patients diagnosed with ALI/ARDS whom underwent recruitment manoeuvre is carried out. Airway pressure and flow data are used to identify patient-specific constant lung elastance (Elung and time-variant dynamic lung elastance (Edrs at each PEEP level (increments of 5cmH2O, for a single compartment linear lung model using integral-based methods. Optimal PEEP is estimated using Elung versus PEEP, Edrs-Pressure curve and Edrs Area at minimum elastance (maximum compliance and the inflection of the curves (diminishing return. Results are compared to clinically selected PEEP values. The trials and use of the data were approved by the New Zealand South Island Regional Ethics Committee. Results Median absolute percentage fitting error to the data when estimating time-variant Edrs is 0.9% (IQR = 0.5-2.4 and 5.6% [IQR: 1.8-11.3] when estimating constant Elung. Both Elung and Edrs decrease with PEEP to a minimum, before rising, and indicating potential over-inflation. Median Edrs over all patients across all PEEP values was 32.2 cmH2O/l [IQR: 26.1-46.6], reflecting the heterogeneity of ALI/ARDS patients, and their response to PEEP, that complicates standard approaches to PEEP selection. All Edrs-Pressure curves have a clear inflection point before minimum Edrs, making PEEP selection straightforward. Model-based selected PEEP using the proposed metrics were higher than clinically selected values in 7/10 cases. Conclusion Continuous monitoring of the patient-specific Elung and Edrs and minimally invasive PEEP titration provide a unique, patient-specific and physiologically relevant metric to optimize PEEP selection with minimal disruption of MV therapy.

  7. Embracing model-based designs for dose-finding trials. (United States)

    Love, Sharon B; Brown, Sarah; Weir, Christopher J; Harbron, Chris; Yap, Christina; Gaschler-Markefski, Birgit; Matcham, James; Caffrey, Louise; McKevitt, Christopher; Clive, Sally; Craddock, Charlie; Spicer, James; Cornelius, Victoria


    Dose-finding trials are essential to drug development as they establish recommended doses for later-phase testing. We aim to motivate wider use of model-based designs for dose finding, such as the continual reassessment method (CRM). We carried out a literature review of dose-finding designs and conducted a survey to identify perceived barriers to their implementation. We describe the benefits of model-based designs (flexibility, superior operating characteristics, extended scope), their current uptake, and existing resources. The most prominent barriers to implementation of a model-based design were lack of suitable training, chief investigators' preference for algorithm-based designs (e.g., 3+3), and limited resources for study design before funding. We use a real-world example to illustrate how these barriers can be overcome. There is overwhelming evidence for the benefits of CRM. Many leading pharmaceutical companies routinely implement model-based designs. Our analysis identified barriers for academic statisticians and clinical academics in mirroring the progress industry has made in trial design. Unified support from funders, regulators, and journal editors could result in more accurate doses for later-phase testing, and increase the efficiency and success of clinical drug development. We give recommendations for increasing the uptake of model-based designs for dose-finding trials in academia.

  8. Model-Based Reconstructive Elasticity Imaging Using Ultrasound

    Directory of Open Access Journals (Sweden)

    Salavat R. Aglyamov


    Full Text Available Elasticity imaging is a reconstructive imaging technique where tissue motion in response to mechanical excitation is measured using modern imaging systems, and the estimated displacements are then used to reconstruct the spatial distribution of Young's modulus. Here we present an ultrasound elasticity imaging method that utilizes the model-based technique for Young's modulus reconstruction. Based on the geometry of the imaged object, only one axial component of the strain tensor is used. The numerical implementation of the method is highly efficient because the reconstruction is based on an analytic solution of the forward elastic problem. The model-based approach is illustrated using two potential clinical applications: differentiation of liver hemangioma and staging of deep venous thrombosis. Overall, these studies demonstrate that model-based reconstructive elasticity imaging can be used in applications where the geometry of the object and the surrounding tissue is somewhat known and certain assumptions about the pathology can be made.

  9. Model Based Mission Assurance: Emerging Opportunities for Robotic Systems (United States)

    Evans, John W.; DiVenti, Tony


    The emergence of Model Based Systems Engineering (MBSE) in a Model Based Engineering framework has created new opportunities to improve effectiveness and efficiencies across the assurance functions. The MBSE environment supports not only system architecture development, but provides for support of Systems Safety, Reliability and Risk Analysis concurrently in the same framework. Linking to detailed design will further improve assurance capabilities to support failures avoidance and mitigation in flight systems. This also is leading new assurance functions including model assurance and management of uncertainty in the modeling environment. Further, the assurance cases, a structured hierarchal argument or model, are emerging as a basis for supporting a comprehensive viewpoint in which to support Model Based Mission Assurance (MBMA).

  10. Toward a Model-Based Approach for Flight System Fault Protection (United States)

    Day, John; Meakin, Peter; Murray, Alex


    Use SysML/UML to describe the physical structure of the system This part of the model would be shared with other teams - FS Systems Engineering, Planning & Execution, V&V, Operations, etc., in an integrated model-based engineering environment Use the UML Profile mechanism, defining Stereotypes to precisely express the concepts of the FP domain This extends the UML/SysML languages to contain our FP concepts Use UML/SysML, along with our profile, to capture FP concepts and relationships in the model Generate typical FP engineering products (the FMECA, Fault Tree, MRD, V&V Matrices)

  11. A model based message passing approach for flexible and scalable home automation controllers

    Energy Technology Data Exchange (ETDEWEB)

    Bienhaus, D. [INNIAS GmbH und Co. KG, Frankenberg (Germany); David, K.; Klein, N.; Kroll, D. [ComTec Kassel Univ., SE Kassel Univ. (Germany); Heerdegen, F.; Jubeh, R.; Zuendorf, A. [Kassel Univ. (Germany). FG Software Engineering; Hofmann, J. [BSC Computer GmbH, Allendorf (Germany)


    There is a large variety of home automation systems that are largely proprietary systems from different vendors. In addition, the configuration and administration of home automation systems is frequently a very complex task especially, if more complex functionality shall be achieved. Therefore, an open model for home automation was developed that is especially designed for easy integration of various home automation systems. This solution also provides a simple modeling approach that is inspired by typical home automation components like switches, timers, etc. In addition, a model based technology to achieve rich functionality and usability was implemented. (orig.)

  12. Model-based monitoring techniques for leakage localization in distribution water networks


    Meseguer Amela, Jordi; Mirats Tur, Josep Maria; Cembrano Gennari, Gabriela; Puig Cayuela, Vicenç


    This is an open access article under the CC BY-NC-ND license This paper describes an integrated model-based monitoring framework for leakage localization in district-metered areas (DMA) of water distribution networks, which takes advantage of the availability of a hydraulic model of the network. The leakage localization methodology is based on the use of flow and pressure sensors at the DMA inlets and a limited number of pressure sensors deployed inside the DMA. The placement of these sens...

  13. Model Based Analysis and Test Generation for Flight Software (United States)

    Pasareanu, Corina S.; Schumann, Johann M.; Mehlitz, Peter C.; Lowry, Mike R.; Karsai, Gabor; Nine, Harmon; Neema, Sandeep


    We describe a framework for model-based analysis and test case generation in the context of a heterogeneous model-based development paradigm that uses and combines Math- Works and UML 2.0 models and the associated code generation tools. This paradigm poses novel challenges to analysis and test case generation that, to the best of our knowledge, have not been addressed before. The framework is based on a common intermediate representation for different modeling formalisms and leverages and extends model checking and symbolic execution tools for model analysis and test case generation, respectively. We discuss the application of our framework to software models for a NASA flight mission.

  14. Towards model-based testing of electronic funds transfer systems


    Asaadi, H.R.; Khosravi, R.; Mousavi, M.R.; Noroozi, N.


    We report on our first experience with applying model-based testing techniques to an operational Electronic Funds Transfer (EFT) switch. The goal is to test the conformance of the EFT switch to the standard flows described by the ISO 8583 standard. To this end, we first make a formalization of the transaction flows specified in the ISO 8583 standard in terms of a Labeled Transition System (LTS). This formalization paves the way for model-based testing based on the formal notion of Input-Outpu...

  15. High-dose amrinone is required to accelerate rewarming from deliberate mild intraoperative hypothermia for neurosurgical procedures. (United States)

    Inoue, Satoki; Kawaguchi, Masahiko; Sakamoto, Takanori; Kitaguchi, Katsuyasu; Furuya, Hitoshi; Sakaki, Toshisuke


    group were significantly faster and lower, respectively, than in the control group. Systemic vascular resistance in the AMR 15 group was smaller than in the control group throughout the study; on the other hand, only the value after the start of rewarming in the ReAMR group was smaller than in the control group. Amrinone at an infusion rate of 15 or 5 microg x kg(-1) x min(-1) with a reloading at the beginning of rewarming accelerated the rewarming rate of core temperature during deliberate mild hypothermia. This suggests that high-dose amrinone is required to accelerate rewarming from deliberate mild intraoperative hypothermia for neurosurgical procedures.

  16. Evaluation of Sensory and Motor Skills in Neurosurgery Applicants Using a Virtual Reality Neurosurgical Simulator: The Sensory-Motor Quotient. (United States)

    Roitberg, Ben Z; Kania, Patrick; Luciano, Cristian; Dharmavaram, Naga; Banerjee, Pat


    Manual skill is an important attribute for any surgeon. Current methods to evaluate sensory-motor skills in neurosurgical residency applicants are limited. We aim to develop an objective multifaceted measure of sensory-motor skills using a virtual reality surgical simulator. A set of 3 tests of sensory-motor function was performed using a 3-dimensional surgical simulator with head and arm tracking, collocalization, and haptic feedback. (1) Trajectory planning: virtual reality drilling of a pedicle. Entry point, target point, and trajectory were scored-evaluating spatial memory and orientation. (2) Motor planning: sequence, timing, and precision: hemostasis in a postresection cavity in the brain. (3) Haptic perception: touching virtual spheres to determine which is softest of the group, with progressive difficulty. Results were analyzed individually and for a combined score of all the tasks. The University of Chicago Hospital's tertiary care academic center. A total of 95 consecutive applicants interviewed at a neurosurgery residency program over 2 years were offered anonymous participation in the study; in 2 cohorts, 36 participants in year 1 and 27 participants in year 2 (validation cohort) agreed and completed all the tasks. We also tested 10 first-year medical students and 4 first- and second-year neurosurgery residents. A cumulative score was generated from the 3 tests. The mean score was 14.47 (standard deviation = 4.37), median score was 13.42, best score was 8.41, and worst score was 30.26. Separate analysis of applicants from each of 2 years yielded nearly identical results. Residents tended to cluster on the better performance side, and first-year students were not different from applicants. (1) Our cumulative score measures sensory-motor skills in an objective and reproducible way. (2) Better performance by residents hints at validity for neurosurgery. (3) We were able to demonstrate good psychometric qualities and generate a proposed sensory

  17. Treatment biases in traumatic neurosurgical care: a retrospective study of the Nationwide Inpatient Sample from 1998 to 2009. (United States)

    McCutcheon, Brandon A; Chang, David C; Marcus, Logan; Gonda, David D; Noorbakhsh, Abraham; Chen, Clark C; Talamini, Mark A; Carter, Bob S


    This study was designed to assess the relationship between insurance status and likelihood of receiving a neurosurgical procedure following admission for either extraaxial intracranial hemorrhage or spinal vertebral fracture. A retrospective analysis of the Nationwide Inpatient Sample (NIS; 1998-2009) was performed. Cases of traumatic extraaxial intracranial hematoma and spinal vertebral fracture were identified using International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes. Within this cohort, those patients receiving a craniotomy or spinal fusion and/or decompression in the context of an admission for traumatic brain or spine injury, respectively, were identified using the appropriate ICD-9 procedure codes. A total of 190,412 patients with extraaxial intracranial hematoma were identified between 1998 and 2009. Within this cohort, 37,434 patients (19.7%) received a craniotomy. A total of 477,110 patients with spinal vertebral fracture were identified. Of these, 37,302 (7.8%) received a spinal decompression and/or fusion. On multivariate analysis controlling for patient demographics, severity of injuries, comorbidities, hospital volume, and hospital characteristics, uninsured patients had a reduced likelihood of receiving a craniotomy (odds ratio [OR] 0.76, 95% confidence interval [CI] 0.71-0.82) and spinal fusion (OR 0.67, 95% CI 0.64-0.71) relative to insured patients. This statistically significant trend persisted when uninsured and insured patients were matched on the basis of mortality propensity score. Uninsured patients demonstrated an elevated risk-adjusted mortality rate relative to insured patients in cases of extraaxial intracranial hematoma. Among patients with spinal injury, mortality rates were similar between patients with and without insurance. In this study, uninsured patients were consistently less likely to receive a craniotomy or spinal fusion for traumatic intracranial extraaxial hemorrhage and spinal vertebral fracture

  18. Can the transition process from foundation doctor to neurosurgical specialty trainee be improved through “learner-centered induction programs”?

    Directory of Open Access Journals (Sweden)

    Acharya V


    skills in a safe environment under senior supervision, prior to starting on the wards. Finally, as the induction program was of a greater duration than the traditional half day, they felt they had sufficient time to ask questions and address concerns while “on the job”. Overall, “learner-centered induction programs” did appear to show promise in this pilot study with regards to increasing the confidence of junior doctors starting a neurosurgical placement and helped ease the transition process from foundation doctor to specialty trainee in neurosurgery. We believe further work to formalize and quantify these findings using questionnaires and a larger sample group as well as across successive is indicated and may help junior doctor learning and transition processes in future practice. Keywords: induction programs, foundation training, transition processes, junior doctor transitions

  19. Processos inflamatorios cronicos do sistema nervoso central: aspectos neurocirurgicos Inflamatory chronic processes of the central nervous system: neurosurgical aspects

    Directory of Open Access Journals (Sweden)

    Nubor Orlando Facure


    Full Text Available São relatados 35 casos de pacientes com síndrome de hipertensão intra-craniana causada por processos inflamatórios crônicos do sistema nervoso central. Apesar da multiplicidade dos agentes etiológicos, a conduta neuro-cirúrgica para a solução da hipertensão intracraniana é semelhante nestes processos. Os pacientes foram divididos em dois grupos. O grupo 1 inclui 7 pacientes nos quais o quadro clínico e neuro-radiológico era de lesão expansiva intracerebral. Estes pacientes foram submetidos a cranotomia com exerese do processo expansivo: tratava-se de cisticercos múltiplos em 5 casos, tuberculoma em um e granuloma blastomicótico em outro. A mortalidade foi nula e não houve recidiva da hipertensão intracraniana. Nos pacientes do grupo 2 as lesões fundamentais são representadas pela ependimite granulosa e leptomeningite crônica das cisternas basais. Os quadros clínico e neuro-radiológico são de hidrocefalia com dilatação ventricular e frequentemente sem sintais neurológicos focais. O prognóstico nestes casos é mais grave devido quase sempre à progressão da doença. Nos 28 pacientes incluídos neste grupo o tratamento de escolha foi a derivação ventriculoatrial ou ventrículoperitonial. A mortalidade foi de 39,2%.A study into the neurosurgical approach to thirty-five patients with increased intracranial pressure due to inflamatory diseases affecting the central nervous system and meninges is reported. The entities under consideration were found to have similar surgical aspects despite the heterogeneity of etiologic agents. As regards the surgical treatment, two groups of cases were recognized. Group 1 comprises 7 patientes with symptoms of a space-occupying lesion; in these patients craniotomies were perfomed with good results. Group 2 included the remainder 28 cases with acquired hydrocephalus. In this group differents methods for ventricular drainage were used, but ventriculo-auriculostomy and specially ventriculo

  20. Model-based safety analysis of a control system using Simulink and Simscape extended models

    Directory of Open Access Journals (Sweden)

    Shao Nian


    Full Text Available The aircraft or system safety assessment process is an integral part of the overall aircraft development cycle. It is usually characterized by a very high timely and financial effort and can become a critical design driver in certain cases. Therefore, an increasing demand of effective methods to assist the safety assessment process arises within the aerospace community. One approach is the utilization of model-based technology, which is already well-established in the system development, for safety assessment purposes. This paper mainly describes a new tool for Model-Based Safety Analysis. A formal model for an example system is generated and enriched with extended models. Then, system safety analyses are performed on the model with the assistance of automation tools and compared to the results of a manual analysis. The objective of this paper is to improve the increasingly complex aircraft systems development process. This paper develops a new model-based analysis tool in Simulink/Simscape environment.

  1. Designing the database for a reliability aware Model-Based System Engineering process

    International Nuclear Information System (INIS)

    Cressent, Robin; David, Pierre; Idasiak, Vincent; Kratz, Frederic


    This article outlines the need for a reliability database to implement model-based description of components failure modes and dysfunctional behaviors. We detail the requirements such a database should honor and describe our own solution: the Dysfunctional Behavior Database (DBD). Through the description of its meta-model, the benefits of integrating the DBD in the system design process is highlighted. The main advantages depicted are the possibility to manage feedback knowledge at various granularity and semantic levels and to ease drastically the interactions between system engineering activities and reliability studies. The compliance of the DBD with other reliability database such as FIDES is presented and illustrated. - Highlights: ► Model-Based System Engineering is more and more used in the industry. ► It results in a need for a reliability database able to deal with model-based description of dysfunctional behavior. ► The Dysfunctional Behavior Database aims to fulfill that need. ► It helps dealing with feedback management thanks to its structured meta-model. ► The DBD can profit from other reliability database such as FIDES.

  2. Model-based energy monitoring and diagnosis of telecommunication cooling systems

    International Nuclear Information System (INIS)

    Sorrentino, Marco; Acconcia, Matteo; Panagrosso, Davide; Trifirò, Alena


    A methodology is proposed for on-line monitoring of cooling load supplied by Telecommunication (TLC) cooling systems. Sensible cooling load is estimated via a proportional integral controller-based input estimator, whereas a lumped parameters model was developed aiming at estimating air handling units (AHUs) latent heat load removal. The joint deployment of above estimators enables accurate prediction of total cooling load, as well as of related AHUs and free-coolers energy performance. The procedure was then proven effective when extended to cooling systems having a centralized chiller, through model-based estimation of a key performance metric, such as the energy efficiency ratio. The results and experimental validation presented throughout the paper confirm the suitability of the proposed procedure as a reliable and effective energy monitoring and diagnostic tool for TLC applications. Moreover, the proposed modeling approach, beyond its direct contribution towards smart use and conservation of energy, can be fruitfully deployed as a virtual sensor of removed heat load into a variety of residential and industrial applications. - Highlights: • Accurate cooling load prediction in telecommunication rooms. • Development of an input-estimator for sensible cooling load simulation. • Model-based estimation of latent cooling load. • Model-based prediction of centralized chiller energy performance in central offices. • Diagnosis-oriented application of proposed cooling load estimator.

  3. Video clip transfer of radiological images using a mobile telephone in emergency neurosurgical consultations (3G Multi-Media Messaging Service). (United States)

    Waran, Vicknes; Bahuri, Nor Faizal Ahmad; Narayanan, Vairavan; Ganesan, Dharmendra; Kadir, Khairul Azmi Abdul


    The purpose of this study was to validate and assess the accuracy and usefulness of sending short video clips in 3gp file format of an entire scan series of patients, using mobile telephones running on 3G-MMS technology, to enable consultation between junior doctors in a neurosurgical unit and the consultants on-call after office hours. A total of 56 consecutive patients with acute neurosurgical problems requiring urgent after-hours consultation during a 6-month period, prospectively had their images recorded and transmitted using the above method. The response to the diagnosis and the management plan by two neurosurgeons (who were not on site) based on the images viewed on a mobile telephone were reviewed by an independent observer and scored. In addition to this, a radiologist reviewed the original images directly on the hospital's Patients Archiving and Communication System (PACS) and this was compared with the neurosurgeons' response. Both neurosurgeons involved in this study were in complete agreement with their diagnosis. The radiologist disagreed with the diagnosis in only one patient, giving a kappa coefficient of 0.88, indicating an almost perfect agreement. The use of mobile telephones to transmit MPEG video clips of radiological images is very advantageous for carrying out emergency consultations in neurosurgery. The images accurately reflect the pathology in question, thereby reducing the incidence of medical errors from incorrect diagnosis, which otherwise may just depend on a verbal description.

  4. Quantitative analysis of magnetic resonance imaging susceptibility artifacts caused by neurosurgical biomaterials. Comparison of 0.5, 1.5, and 3.0 tesla magnetic fields

    International Nuclear Information System (INIS)

    Matsuura, Hideki; Inoue, Takashi; Ogasawara, Kuniaki; Sasaki, Makoto; Konno, Hiromu; Kuzu, Yasutaka; Nishimoto, Hideaki; Ogawa, Akira


    Magnetic resonance (MR) imaging is an important diagnostic tool for neurosurgical diseases but susceptibility artifacts caused by biomaterial instrumentation frequently causes difficulty in visualizing postoperative changes. The susceptibility artifacts caused by neurosurgical biomaterials were compared quantitatively by 0.5, 1.5, and 3.0 Tesla MR imaging. MR imaging of uniform size and shape of pieces ceramic (zirconia), pure titanium, titanium alloy, and cobalt-based alloy was performed at 0.5, 1.5, and 3.0 Tesla. A linear region of interest was defined across the center of the biomaterial in the transverse direction, and the susceptibility artifact diameter was calculated. Susceptibility artifacts developed around all biomaterials at all magnetic field strengths. The artifact diameters caused by pure titanium, titanium alloy, and cobalt-based alloy increased in the order of 0.5, 1.5, to 3.0 Tesla magnetic fields. The artifact diameter of ceramic was not influenced by magnetic field strength, and was the smallest of all biomaterials at all magnetic field strengths. The artifacts caused by biomaterials except ceramic increase with the magnetic field strength. Ceramic instrumentation will minimize artifacts in all magnetic fields. (author)

  5. Prevention of deep vein thrombosis in potential neurosurgical patients. A randomized trial comparing graduated compression stockings alone or graduated compression stockings plus intermittent pneumatic compression with control

    International Nuclear Information System (INIS)

    Turpie, A.G.; Hirsh, J.; Gent, M.; Julian, D.; Johnson, J.


    In a randomized trial of neurosurgical patients, groups wearing graduated compression stockings alone (group 1) or graduated compression stockings plus intermittent pneumatic compression (IPC) (group 2) were compared with an untreated control group in the prevention of deep vein thrombosis (DVT). In both active treatment groups, the graduated compression stockings were continued for 14 days or until hospital discharge, if earlier. In group 2, IPC was continued for seven days. All patients underwent DVT surveillance with iodine 125-labeled fibrinogen leg scanning and impedance plethysmography. Venography was carried out if either test became abnormal. Deep vein thrombosis occurred in seven (8.8%) of 80 patients in group 1, in seven (9.0%) of 78 patients in group 2, and in 16 (19.8%) of 81 patients in the control group. The observed differences among these rates are statistically significant. The results of this study indicate that graduated compression stockings alone or in combination with IPC are effective methods of preventing DVT in neurosurgical patients

  6. The Korean Spinal Neurosurgery Society ; Are We Reimbursed Properly for Spinal Neurosurgical Practices under the Korean Resource Based Relative Value Scale Service? (United States)

    Kwon, Woo-Keun; Kim, Joo Han; Moon, Hong Joo; Park, Youn-Kwan


    Objectives The Korean Resource Based Relative Value Scale (K-RBRVS) was introduced in 2001 as an alternative of the previous medical fee schedule. Unfortunately, most neurosurgeons are unfamiliar with the details of the K-RBRVS and how it affects the reimbursement rates for the surgical procedures we perform. We summarize the K-RBRVS in brief, and discuss on how the relative value (RV) of the spinal neurosurgical procedures have changed since the introduction in 2001. Methods We analyzed the change of spinal procedure RVs since 2001, and compared it with the change of values in the brain neurosurgical procedures. RVs of 88 neurospinal procedures on the list of K-RBRVS were analyzed, while 24 procedures added during annual revisions were excluded. Results During the past 15 years, RVs for spinal procedures have increased 62.8%, which is not so different with the cumulative increase of consumer prices during this time period or the increase rate of 92.3% for brain surgeries. When comparing the change of RVs in more complex procedures between spinal and brain neurosurgery, the increase rate was 125.3% and 133%, respectively. Conclusion More effort of the society of spinal surgeons seems to be needed to get adequate reimbursement, as there have been some discrimination compared to brain surgeons in the increase of RVs. And considering the relative underestimation of spinal neurosurgeons’ labor, more objective measures of neurospinal surgeons’ work and productivity should be developed for impartial reimbursement. PMID:28061492

  7. Non-frontal Model Based Approach to Forensic Face Recognition

    NARCIS (Netherlands)

    Dutta, A.; Veldhuis, Raymond N.J.; Spreeuwers, Lieuwe Jan


    In this paper, we propose a non-frontal model based approach which ensures that a face recognition system always gets to compare images having similar view (or pose). This requires a virtual suspect reference set that consists of non-frontal suspect images having pose similar to the surveillance

  8. Model-Based GUI Testing Using Uppaal at Novo Nordisk

    DEFF Research Database (Denmark)

    H. Hjort, Ulrik; Rasmussen, Jacob Illum; Larsen, Kim Guldstrand


    This paper details a collaboration between Aalborg University and Novo Nordiskin developing an automatic model-based test generation tool for system testing of the graphical user interface of a medical device on an embedded platform. The tool takes as input an UML Statemachine model and generates...

  9. Automated model-based testing of hybrid systems

    NARCIS (Netherlands)

    Osch, van M.P.W.J.


    In automated model-based input-output conformance testing, tests are automati- cally generated from a speci¯cation and automatically executed on an implemen- tation. Input is applied to the implementation and output is observed from the implementation. If the observed output is allowed according to

  10. Model Based Fault Detection in a Centrifugal Pump Application

    DEFF Research Database (Denmark)

    Kallesøe, Carsten; Cocquempot, Vincent; Izadi-Zamanabadi, Roozbeh


    A model based approach for fault detection in a centrifugal pump, driven by an induction motor, is proposed in this paper. The fault detection algorithm is derived using a combination of structural analysis, observer design and Analytical Redundancy Relation (ARR) design. Structural considerations...

  11. Perceptual decision neurosciences: a model-based review

    NARCIS (Netherlands)

    Mulder, M.J.; van Maanen, L.; Forstmann, B.U.


    In this review we summarize findings published over the past 10 years focusing on the neural correlates of perceptual decision-making. Importantly, this review highlights only studies that employ a model-based approach, i.e., they use quantitative cognitive models in combination with neuroscientific

  12. A comparative study of independent particle model based ...

    Indian Academy of Sciences (India)

    We find that among these three independent particle model based methods, the ss-VSCF method provides most accurate results in the thermal averages followed by t-SCF and the v-VSCF is the least accurate. However, the ss-VSCF is found to be computationally very expensive for the large molecules. The t-SCF gives ...

  13. Model-based safety architecture framework for complex systems

    NARCIS (Netherlands)

    Schuitemaker, Katja; Rajabali Nejad, Mohammadreza; Braakhuis, J.G.; Podofillini, Luca; Sudret, Bruno; Stojadinovic, Bozidar; Zio, Enrico; Kröger, Wolfgang


    The shift to transparency and rising need of the general public for safety, together with the increasing complexity and interdisciplinarity of modern safety-critical Systems of Systems (SoS) have resulted in a Model-Based Safety Architecture Framework (MBSAF) for capturing and sharing architectural

  14. Adopting a Models-Based Approach to Teaching Physical Education (United States)

    Casey, Ashley; MacPhail, Ann


    Background: The popularised notion of models-based practice (MBP) is one that focuses on the delivery of a model, e.g. Cooperative Learning, Sport Education, Teaching Personal and Social Responsibility, Teaching Games for Understanding. Indeed, while an abundance of research studies have examined the delivery of a single model and some have…

  15. Model-based analysis and simulation of regenerative heat wheel

    DEFF Research Database (Denmark)

    Wu, Zhuang; Melnik, Roderick V. N.; Borup, F.


    The rotary regenerator (also called the heat wheel) is an important component of energy intensive sectors, which is used in many heat recovery systems. In this paper, a model-based analysis of a rotary regenerator is carried out with a major emphasis given to the development and implementation of...

  16. Towards model-based testing of electronic funds transfer systems

    NARCIS (Netherlands)

    Asaadi, H.R.; Khosravi, R.; Mousavi, M.R.; Noroozi, N.; Arbab, F.; Sirjani, M.


    We report on our first experience with applying model-based testing techniques to an operational Electronic Funds Transfer (EFT) switch. The goal is to test the conformance of the EFT switch to the standard flows described by the ISO 8583 standard. To this end, we first make a formalization of the

  17. Towards model-based testing of electronic funds transfer systems

    NARCIS (Netherlands)

    Asaadi, H.R.; Khosravi, R.; Mousavi, M.R.; Noroozi, N.


    We report on our first experience with applying model-based testing techniques to an operational Electronic Funds Transfer (EFT) switch. The goal is to test the conformance of the EFT switch to the standard flows described by the ISO 8583 standard. To this end, we first make a formalization of the

  18. Model-based monitoring of rotors with multiple coexisting faults

    International Nuclear Information System (INIS)

    Rossner, Markus


    Monitoring systems are applied to many rotors, but only few monitoring systems can separate coexisting errors and identify their quantity. This research project solves this problem using a combination of signal-based and model-based monitoring. The signal-based part performs a pre-selection of possible errors; these errors are further separated with model-based methods. This approach is demonstrated for the errors unbalance, bow, stator-fixed misalignment, rotor-fixed misalignment and roundness errors. For the model-based part, unambiguous error definitions and models are set up. The Ritz approach reduces the model order and therefore speeds up the diagnosis. Identification algorithms are developed for the different rotor faults. Hereto, reliable damage indicators and proper sub steps of the diagnosis have to be defined. For several monitoring problems, measuring both deflection and bearing force is very useful. The monitoring system is verified by experiments on an academic rotor test rig. The interpretation of the measurements requires much knowledge concerning the dynamics of the rotor. Due to the model-based approach, the system can separate errors with similar signal patterns and identify bow and roundness error online at operation speed. [de

  19. Model-Based Engineering of Supervisory Controllers using CIF

    NARCIS (Netherlands)

    Schiffelers, R.R.H.; Theunissen, R.J.M.; Beek, van D.A.; Rooda, J.E.; Levendovsky, T.; Lengyel, L.


    In the Model-Based Engineering (MBE) paradigm, models are the core elements in the design process of a system from its requirements to the actual implementation of the system. By means of Supervisory Control Theory (SCT), supervisory controllers (supervisors) can be synthesized instead of

  20. Product Lifecycle Management Architecture: A Model Based Systems Engineering Analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Noonan, Nicholas James [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    This report is an analysis of the Product Lifecycle Management (PLM) program. The analysis is centered on a need statement generated by a Nuclear Weapons (NW) customer. The need statement captured in this report creates an opportunity for the PLM to provide a robust service as a solution. Lifecycles for both the NW and PLM are analyzed using Model Based System Engineering (MBSE).

  1. Expediting model-based optoacoustic reconstructions with tomographic symmetries

    International Nuclear Information System (INIS)

    Lutzweiler, Christian; Deán-Ben, Xosé Luís; Razansky, Daniel


    Purpose: Image quantification in optoacoustic tomography implies the use of accurate forward models of excitation, propagation, and detection of optoacoustic signals while inversions with high spatial resolution usually involve very large matrices, leading to unreasonably long computation times. The development of fast and memory efficient model-based approaches represents then an important challenge to advance on the quantitative and dynamic imaging capabilities of tomographic optoacoustic imaging. Methods: Herein, a method for simplification and acceleration of model-based inversions, relying on inherent symmetries present in common tomographic acquisition geometries, has been introduced. The method is showcased for the case of cylindrical symmetries by using polar image discretization of the time-domain optoacoustic forward model combined with efficient storage and inversion strategies. Results: The suggested methodology is shown to render fast and accurate model-based inversions in both numerical simulations andpost mortem small animal experiments. In case of a full-view detection scheme, the memory requirements are reduced by one order of magnitude while high-resolution reconstructions are achieved at video rate. Conclusions: By considering the rotational symmetry present in many tomographic optoacoustic imaging systems, the proposed methodology allows exploiting the advantages of model-based algorithms with feasible computational requirements and fast reconstruction times, so that its convenience and general applicability in optoacoustic imaging systems with tomographic symmetries is anticipated

  2. Model based active power control of a wind turbine

    DEFF Research Database (Denmark)

    Mirzaei, Mahmood; Soltani, Mohsen; Poulsen, Niels Kjølstad


    in the electricity market that selling the reserve power is more profitable than producing with the full capacity. Therefore wind turbines can be down-regulated and sell the differential capacity as the reserve power. In this paper we suggest a model based approach to control wind turbines for active power reference...

  3. Nonlinear Model-Based Fault Detection for a Hydraulic Actuator

    NARCIS (Netherlands)

    Van Eykeren, L.; Chu, Q.P.


    This paper presents a model-based fault detection algorithm for a specific fault scenario of the ADDSAFE project. The fault considered is the disconnection of a control surface from its hydraulic actuator. Detecting this type of fault as fast as possible helps to operate an aircraft more cost

  4. Model based decision support for planning of road maintenance

    NARCIS (Netherlands)

    van Harten, Aart; Worm, J.M.; Worm, J.M.


    In this article we describe a Decision Support Model, based on Operational Research methods, for the multi-period planning of maintenance of bituminous pavements. This model is a tool for the road manager to assist in generating an optimal maintenance plan for a road. Optimal means: minimising the

  5. An Approach to Quality Estimation in Model-Based Development

    DEFF Research Database (Denmark)

    Holmegaard, Jens Peter; Koch, Peter; Ravn, Anders Peter


    We present an approach to estimation of parameters for design space exploration in Model-Based Development, where synthesis of a system is done in two stages. Component qualities like space, execution time or power consumption are defined in a repository by platform dependent values. Connectors...

  6. A Pilot Project of Early Integrated Traumatic Brain Injury Rehabilitation in Singapore

    Directory of Open Access Journals (Sweden)

    Siew Kwaon Lui


    Full Text Available Objective. Document acute neurosurgical and rehabilitation parameters of patients of all traumatic brain injury (TBI severities and determine whether early screening along with very early integrated TBI rehabilitation changes functional outcomes. Methods. Prospective study involving all patients with TBI admitted to a neurosurgical department of a tertiary hospital. They were assessed within 72 hours of admission by the rehabilitation team and received twice weekly rehabilitation reviews. Patients with further rehabilitation needs were then transferred to the attached acute inpatient TBI rehabilitation unit (TREATS and their functional outcomes were compared against a historical group of patients. Demographic variables, acute neurosurgical characteristics, medical complications, and rehabilitation outcomes were recorded. Results. There were 298 patients screened with an average age of 61.8±19.1 years. The most common etiology was falls (77.5%. Most patients were discharged home directly (67.4% and 22.8% of patients were in TREATS. The TREATS group functionally improved (P<0.001. Regression analysis showed by the intervention of TREATS, that there was a statistically significant FIM functional gain of 18.445 points (95% CI −30.388 to −0.6502, P=0.03. Conclusion. Our study demonstrated important epidemiological data on an unselected cohort of patients with TBI in Singapore and functional improvement in patients who further received inpatient rehabilitation.

  7. Switching costs in Information Technology: the proposal of an integrated taxonomic model based on literature Custos de Troca em Tecnologia da Informação: a Proposição de um Modelo Taxonômico Integrado a partir da Literatura

    Directory of Open Access Journals (Sweden)

    Ricardo Engelbert


    Full Text Available

    The aim of this paper is to propose an integrated taxonomic model for the switching costs in Information Technology (IT. These costs play a decisive role in the organizations’ process of technology change, and they may limit or even prevent their occurrence, thus reducing the business’s flexibility to adjust to new environmental conditions. Due to the imprisonment they can impose to the organization, it is important to study the switching costs and the way to assess them in order to reduce their impact on the decision-making process involving the adoption of new technologies. The constructs composing the comprehensive model were obtained through thorough literature analysis in the fields of strategy, economics, marketing, information systems, and psychology. Definitions found in the several studies published in these areas were analyzed from the levels of solution, supplier, and management processes involved in the switching of technology, including a temporal perspective. The costs were classified as: selection costs, activation costs, building costs, formal costs, psychological costs, opportunity costs, and costs involved in going back to the previous solution. Since the model’s ambitions are only descriptive of the switching costs, and considering it was based in other studies that, on their turn, are supported in the practice of the business market and in the human behavior in decision-making processes, the model does not need an empirical validation in order to be readily used. Nonetheless, future studies may focus on identifying what costs are predominant in what situations and the intensity with which decision-makers observe each kind of switching cost. This will make the model both explanatory and descriptive.

    Este artigo tem como objetivo a proposição de um modelo taxonômico integrado para os custos de troca em tecnologia da informa

  8. Use of Model-Based Design Methods for Enhancing Resiliency Analysis of Unmanned Aerial Vehicles (United States)

    Knox, Lenora A.

    The most common traditional non-functional requirement analysis is reliability. With systems becoming more complex, networked, and adaptive to environmental uncertainties, system resiliency has recently become the non-functional requirement analysis of choice. Analysis of system resiliency has challenges; which include, defining resilience for domain areas, identifying resilience metrics, determining resilience modeling strategies, and understanding how to best integrate the concepts of risk and reliability into resiliency. Formal methods that integrate all of these concepts do not currently exist in specific domain areas. Leveraging RAMSoS, a model-based reliability analysis methodology for Systems of Systems (SoS), we propose an extension that accounts for resiliency analysis through evaluation of mission performance, risk, and cost using multi-criteria decision-making (MCDM) modeling and design trade study variability modeling evaluation techniques. This proposed methodology, coined RAMSoS-RESIL, is applied to a case study in the multi-agent unmanned aerial vehicle (UAV) domain to investigate the potential benefits of a mission architecture where functionality to complete a mission is disseminated across multiple UAVs (distributed) opposed to being contained in a single UAV (monolithic). The case study based research demonstrates proof of concept for the proposed model-based technique and provides sufficient preliminary evidence to conclude which architectural design (distributed vs. monolithic) is most resilient based on insight into mission resilience performance, risk, and cost in addition to the traditional analysis of reliability.

  9. Model-Based Development of Control Systems for Forestry Cranes

    Directory of Open Access Journals (Sweden)

    Pedro La Hera


    Full Text Available Model-based methods are used in industry for prototyping concepts based on mathematical models. With our forest industry partners, we have established a model-based workflow for rapid development of motion control systems for forestry cranes. Applying this working method, we can verify control algorithms, both theoretically and practically. This paper is an example of this workflow and presents four topics related to the application of nonlinear control theory. The first topic presents the system of differential equations describing the motion dynamics. The second topic presents nonlinear control laws formulated according to sliding mode control theory. The third topic presents a procedure for model calibration and control tuning that are a prerequisite to realize experimental tests. The fourth topic presents the results of tests performed on an experimental crane specifically equipped for these tasks. Results of these studies show the advantages and disadvantages of these control algorithms, and they highlight their performance in terms of robustness and smoothness.

  10. A sediment graph model based on SCS-CN method (United States)

    Singh, P. K.; Bhunya, P. K.; Mishra, S. K.; Chaube, U. C.


    SummaryThis paper proposes new conceptual sediment graph models based on coupling of popular and extensively used methods, viz., Nash model based instantaneous unit sediment graph (IUSG), soil conservation service curve number (SCS-CN) method, and Power law. These models vary in their complexity and this paper tests their performance using data of the Nagwan watershed (area = 92.46 km 2) (India). The sensitivity of total sediment yield and peak sediment flow rate computations to model parameterisation is analysed. The exponent of the Power law, β, is more sensitive than other model parameters. The models are found to have substantial potential for computing sediment graphs (temporal sediment flow rate distribution) as well as total sediment yield.

  11. Automated extraction of knowledge for model-based diagnostics (United States)

    Gonzalez, Avelino J.; Myler, Harley R.; Towhidnejad, Massood; Mckenzie, Frederic D.; Kladke, Robin R.


    The concept of accessing computer aided design (CAD) design databases and extracting a process model automatically is investigated as a possible source for the generation of knowledge bases for model-based reasoning systems. The resulting system, referred to as automated knowledge generation (AKG), uses an object-oriented programming structure and constraint techniques as well as internal database of component descriptions to generate a frame-based structure that describes the model. The procedure has been designed to be general enough to be easily coupled to CAD systems that feature a database capable of providing label and connectivity data from the drawn system. The AKG system is capable of defining knowledge bases in formats required by various model-based reasoning tools.

  12. Bond graph model-based fault diagnosis of hybrid systems

    CERN Document Server

    Borutzky, Wolfgang


    This book presents a bond graph model-based approach to fault diagnosis in mechatronic systems appropriately represented by a hybrid model. The book begins by giving a survey of the fundamentals of fault diagnosis and failure prognosis, then recalls state-of-art developments referring to latest publications, and goes on to discuss various bond graph representations of hybrid system models, equations formulation for switched systems, and simulation of their dynamic behavior. The structured text: • focuses on bond graph model-based fault detection and isolation in hybrid systems; • addresses isolation of multiple parametric faults in hybrid systems; • considers system mode identification; • provides a number of elaborated case studies that consider fault scenarios for switched power electronic systems commonly used in a variety of applications; and • indicates that bond graph modelling can also be used for failure prognosis. In order to facilitate the understanding of fault diagnosis and the presented...

  13. Fuzzy model-based observers for fault detection in CSTR. (United States)

    Ballesteros-Moncada, Hazael; Herrera-López, Enrique J; Anzurez-Marín, Juan


    Under the vast variety of fuzzy model-based observers reported in the literature, what would be the properone to be used for fault detection in a class of chemical reactor? In this study four fuzzy model-based observers for sensor fault detection of a Continuous Stirred Tank Reactor were designed and compared. The designs include (i) a Luenberger fuzzy observer, (ii) a Luenberger fuzzy observer with sliding modes, (iii) a Walcott-Zak fuzzy observer, and (iv) an Utkin fuzzy observer. A negative, an oscillating fault signal, and a bounded random noise signal with a maximum value of ±0.4 were used to evaluate and compare the performance of the fuzzy observers. The Utkin fuzzy observer showed the best performance under the tested conditions. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  14. Fusing Quantitative Requirements Analysis with Model-based Systems Engineering (United States)

    Cornford, Steven L.; Feather, Martin S.; Heron, Vance A.; Jenkins, J. Steven


    A vision is presented for fusing quantitative requirements analysis with model-based systems engineering. This vision draws upon and combines emergent themes in the engineering milieu. "Requirements engineering" provides means to explicitly represent requirements (both functional and non-functional) as constraints and preferences on acceptable solutions, and emphasizes early-lifecycle review, analysis and verification of design and development plans. "Design by shopping" emphasizes revealing the space of options available from which to choose (without presuming that all selection criteria have previously been elicited), and provides means to make understandable the range of choices and their ramifications. "Model-based engineering" emphasizes the goal of utilizing a formal representation of all aspects of system design, from development through operations, and provides powerful tool suites that support the practical application of these principles. A first step prototype towards this vision is described, embodying the key capabilities. Illustrations, implications, further challenges and opportunities are outlined.

  15. MTK: An AI tool for model-based reasoning (United States)

    Erickson, William K.; Schwartz, Mary R.


    A 1988 goal for the Systems Autonomy Demonstration Project Office of the NASA Ames Research Center is to apply model-based representation and reasoning techniques in a knowledge-based system that will provide monitoring, fault diagnosis, control and trend analysis of the space station Thermal Management System (TMS). A number of issues raised during the development of the first prototype system inspired the design and construction of a model-based reasoning tool called MTK, which was used in the building of the second prototype. These issues are outlined, along with examples from the thermal system to highlight the motivating factors behind them. An overview of the capabilities of MTK is given.

  16. Route Choice Model Based on Game Theory for Commuters

    Directory of Open Access Journals (Sweden)

    Licai Yang


    Full Text Available The traffic behaviours of commuters may cause traffic congestion during peak hours. Advanced Traffic Information System can provide dynamic information to travellers. Due to the lack of timeliness and comprehensiveness, the provided information cannot satisfy the travellers’ needs. Since the assumptions of traditional route choice model based on Expected Utility Theory conflict with the actual situation, a route choice model based on Game Theory is proposed to provide reliable route choice to commuters in actual situation in this paper. The proposed model treats the alternative routes as game players and utilizes the precision of predicted information and familiarity of traffic condition to build a game. The optimal route can be generated considering Nash Equilibrium by solving the route choice game. Simulations and experimental analysis show that the proposed model can describe the commuters’ routine route choice decisionexactly and the provided route is reliable.

  17. Model-based dispersive wave processing: A recursive Bayesian solution

    International Nuclear Information System (INIS)

    Candy, J.V.; Chambers, D.H.


    Wave propagation through dispersive media represents a significant problem in many acoustic applications, especially in ocean acoustics, seismology, and nondestructive evaluation. In this paper we propose a propagation model that can easily represent many classes of dispersive waves and proceed to develop the model-based solution to the wave processing problem. It is shown that the underlying wave system is nonlinear and time-variable requiring a recursive processor. Thus the general solution to the model-based dispersive wave enhancement problem is developed using a Bayesian maximum a posteriori (MAP) approach and shown to lead to the recursive, nonlinear extended Kalman filter (EKF) processor. The problem of internal wave estimation is cast within this framework. The specific processor is developed and applied to data synthesized by a sophisticated simulator demonstrating the feasibility of this approach. copyright 1999 Acoustical Society of America.

  18. GENI: A graphical environment for model-based control

    International Nuclear Information System (INIS)

    Kleban, S.; Lee, M.; Zambre, Y.


    A new method to operate machine and beam simulation programs for accelerator control has been developed. Existing methods, although cumbersome, have been used in control systems for commissioning and operation of many machines. We developed GENI, a generalized graphical interface to these programs for model-based control. This ''object-oriented''-like environment is described and some typical applications are presented. 4 refs., 5 figs

  19. Energy, mass, model-based displays, and memory recall

    International Nuclear Information System (INIS)

    Beltracchi, L.


    The operation of a pressurized water reactor in the context of the conservation laws for energy and mass is discussed. These conservation laws are the basis of the Rankine heat engine cycle. Computer graphic implementation of the heat engine cycle, in terms of temperature-entropy coordinates for water, serves as a model-based display of the plant process. A human user of this display, trained in first principles of the process, may exercise a monitoring strategy based on the conservation laws

  20. European Climate - Energy Security Nexus. A model based scenario analysis

    International Nuclear Information System (INIS)

    Criqui, Patrick; Mima, Silvana


    In this research, we have provided an overview of the climate-security nexus in the European sector through a model based scenario analysis with POLES model. The analysis underline that under stringent climate policies, Europe take advantage of a double dividend in its capacity to develop a new cleaner energy model and in lower vulnerability to potential shocks on the international energy markets. (authors)

  1. Constrained convex minimization via model-based excessive gap


    Tran Dinh, Quoc; Cevher, Volkan


    We introduce a model-based excessive gap technique to analyze first-order primal- dual methods for constrained convex minimization. As a result, we construct new primal-dual methods with optimal convergence rates on the objective residual and the primal feasibility gap of their iterates separately. Through a dual smoothing and prox-function selection strategy, our framework subsumes the augmented Lagrangian, and alternating methods as special cases, where our rates apply.

  2. Trojan detection model based on network behavior analysis

    International Nuclear Information System (INIS)

    Liu Junrong; Liu Baoxu; Wang Wenjin


    Based on the analysis of existing Trojan detection technology, this paper presents a Trojan detection model based on network behavior analysis. First of all, we abstract description of the Trojan network behavior, then according to certain rules to establish the characteristic behavior library, and then use the support vector machine algorithm to determine whether a Trojan invasion. Finally, through the intrusion detection experiments, shows that this model can effectively detect Trojans. (authors)

  3. On Model Based Synthesis of Embedded Control Software


    Alimguzhin, Vadim; Mari, Federico; Melatti, Igor; Salvo, Ivano; Tronci, Enrico


    Many Embedded Systems are indeed Software Based Control Systems (SBCSs), that is control systems whose controller consists of control software running on a microcontroller device. This motivates investigation on Formal Model Based Design approaches for control software. Given the formal model of a plant as a Discrete Time Linear Hybrid System and the implementation specifications (that is, number of bits in the Analog-to-Digital (AD) conversion) correct-by-construction control software can be...

  4. Model-based design languages: A case study


    Cibrario Bertolotti, Ivan; Hu, Tingting; Navet, Nicolas


    Fast-paced innovation in the embedded systems domain puts an ever increasing pressure on effective software development methods, leading to the growing popularity of Model-Based Design (MBD). In this context, a proper choice of modeling languages and related tools - depending on design goals and problem qualities - is crucial to make the most of MBD benefits. In this paper, a comparison between two dissimilar approaches to modeling is carried out, with the goal of highlighting their relative ...

  5. Constructing a justice model based on Sen's capability approach


    Yüksel, Sevgi; Yuksel, Sevgi


    The thesis provides a possible justice model based on Sen's capability approach. For this goal, we first analyze the general structure of a theory of justice, identifying the main variables and issues. Furthermore, based on Sen (2006) and Kolm (1998), we look at 'transcendental' and 'comparative' approaches to justice and concentrate on the sufficiency condition for the comparative approach. Then, taking Rawls' theory of justice as a starting point, we present how Sen's capability approach em...

  6. Model-based Recursive Partitioning for Subgroup Analyses


    Seibold, Heidi; Zeileis, Achim; Hothorn, Torsten


    The identification of patient subgroups with differential treatment effects is the first step towards individualised treatments. A current draft guideline by the EMA discusses potentials and problems in subgroup analyses and formulated challenges to the development of appropriate statistical procedures for the data-driven identification of patient subgroups. We introduce model-based recursive partitioning as a procedure for the automated detection of patient subgroups that are identifiable by...



    Rustan, Edhy


    The objectives of the study are to determine: (1) condition on learning creative writing at high school students in Makassar, (2) requirement of learning model in creative writing, (3) program planning and design model in ideal creative writing, (4) feasibility of model study based on creative writing in neurolinguistic programming, and (5) the effectiveness of the learning model based on creative writing in neurolinguisticprogramming.The method of this research uses research development of L...

  8. A tool for model based diagnostics of the AGS Booster

    International Nuclear Information System (INIS)

    Luccio, A.


    A model-based algorithmic tool was developed to search for lattice errors by a systematic analysis of orbit data in the AGS Booster synchrotron. The algorithm employs transfer matrices calculated with MAD between points in the ring. Iterative model fitting of the data allows one to find and eventually correct magnet displacements and angles or field errors. The tool, implemented on a HP-Apollo workstation system, has proved very general and of immediate physical interpretation

  9. GPU-accelerated 3-D model-based tracking

    International Nuclear Information System (INIS)

    Brown, J Anthony; Capson, David W


    Model-based approaches to tracking the pose of a 3-D object in video are effective but computationally demanding. While statistical estimation techniques, such as the particle filter, are often employed to minimize the search space, real-time performance remains unachievable on current generation CPUs. Recent advances in graphics processing units (GPUs) have brought massively parallel computational power to the desktop environment and powerful developer tools, such as NVIDIA Compute Unified Device Architecture (CUDA), have provided programmers with a mechanism to exploit it. NVIDIA GPUs' single-instruction multiple-thread (SIMT) programming model is well-suited to many computer vision tasks, particularly model-based tracking, which requires several hundred 3-D model poses to be dynamically configured, rendered, and evaluated against each frame in the video sequence. Using 6 degree-of-freedom (DOF) rigid hand tracking as an example application, this work harnesses consumer-grade GPUs to achieve real-time, 3-D model-based, markerless object tracking in monocular video.

  10. A practical model-based statistical approach for generating functional test cases: application in the automotive industry


    Awédikian , Roy; Yannou , Bernard


    International audience; With the growing complexity of industrial software applications, industrials are looking for efficient and practical methods to validate the software. This paper develops a model-based statistical testing approach that automatically generates online and offline test cases for embedded software. It discusses an integrated framework that combines solutions for three major software testing research questions: (i) how to select test inputs; (ii) how to predict the expected...

  11. Model-Based Integrated High Penetration Renewables Planning and Control Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bank, Jason [Electrical Distribution Design, Blacksburg, VA (United States); Broadwater, Robert [Electrical Distribution Design, Blacksburg, VA (United States); Cheng, Danling [Electrical Distribution Design, Blacksburg, VA (United States); Costyk, David [Electrical Distribution Design, Blacksburg, VA (United States); Leyo, Mark [Electrical Distribution Design, Blacksburg, VA (United States); Seguin, Richard [Electrical Distribution Design, Blacksburg, VA (United States); Woyak, Jeremy [Electrical Distribution Design, Blacksburg, VA (United States); Acharya-Menon, Amrita [Pepco Holdings, Inc. (PHI), Washington, DC (United States); Steffel, Steve [Pepco Holdings, Inc. (PHI), Washington, DC (United States); Dise, John [Clean Power Research, Napa, CA (United States); Athawale, Rasika [Rutgers Univ., New Brunswick, NJ (United States); Felder, Frank [Rutgers Univ., New Brunswick, NJ (United States)


    Increasing adoption of Solar Photovoltaic (PV) generation at the distribution level poses several changes for the reliable operation of electrical power distribution systems. The addition of a significant amount of PV to a distribution network can introduce a variety of operational problems, including steady-state overvoltages, reverse flows, voltage flicker and excessive controller movement among others. These adverse impacts can be mitigated through a variety of equipment upgrades which represent a cost to either the electric utility or the owner of the PV site. The study performed here aims to quantify the levels of PV generation which present operational problems on a distribution circuit and how those problems might be alleviated. The study performed here included 20 distribution feeders selected from Pepco Holdings, Inc. (PHI) service territory. These feeders are located in the states of Delaware, Maryland and New Jersey. A hosting capacity study was performed on each feeder to determine how much additional PV it could support in its current configuration. Several improvements were then performed on these circuits including phase balancing, capacitor redesign, reducing the voltage regulator set points, fixed power factor operation on the PV inverters and the installation of battery storage. After each of these improvements the hosting capacity of the circuit was reevaluated in order to determine how that particular improvement impacted the amount of PV that could be hosted by the circuit. Each of these improvements represents a real cost in terms of labor and equipment in order to be implemented. They are expected to provide a benefit in terms of the amount of additional PV generation which can be safely interconnected to the distribution feeder. A cost benefit analysis was performed in order to evaluate the expected costs of each feeder improvement and how each one was able to increase the PV hosting capacity of each feeder. It is hoped that these results can be utilized by other distribution utilities in order to understand how they can improve the hosting capacity of their feeders and facilitate the deployment of more PV generation at the distribution level. Admittedly other utility companies will most likely have different feeder architectures and differing labor and equipment costs so the realized cost benefit numbers may be significantly different.

  12. Model-based eco-driving and integrated powertrain control for (hybrid) electric vehicles

    NARCIS (Netherlands)

    Ivens, T.; Spronkmans, S.; Rosca, B.; Wilkins, S.


    The Netherlands Organisation for Applied Scientific Research (TNO) is engaged in research, development and testing of a range of technologies relating to hybrid and electric vehicle energy management and performance. The impact of driver behaviour on vehicle energy consumption is a significant

  13. Integrating Model-Based Learning and Animations for Enhancing Students' Understanding of Proteins Structure and Function (United States)

    Barak, Miri; Hussein-Farraj, Rania


    This paper describes a study conducted in the context of chemistry education reforms in Israel. The study examined a new biochemistry learning unit that was developed to promote in-depth understanding of 3D structures and functions of proteins and nucleic acids. Our goal was to examine whether, and to what extent teaching and learning via…

  14. An Integrated Framework for Model-Based Distributed Diagnosis and Prognosis (United States)

    National Aeronautics and Space Administration — Diagnosis and prognosis are necessary tasks for system re- configuration and fault-adaptive control in complex systems. Diagnosis consists of detection, isolation...

  15. Integration of Bioreactor and Membrane Separation Processes: A Model Based Approach

    DEFF Research Database (Denmark)

    Prado Rubio, Oscar Andres

    and recirculated. The novelty of the process relies in the specialized design and operation of the Reverse Electro-Enhanced Dialysis module. The REED design allows removal of the lactate from the fermentation broth and simultaneously facilitates pH control in the fermenter using hydroxide. Additionally...... density constraint. Through dynamic simulations, the system behavior is investigated under current reversal conditions. Several phenomena are predicted such as preferable ion transport at the interfaces, transient flux inversion and accumulation/depletion of ions within the membranes. The combination...

  16. Innovation in Integrated Chemical Product-Process Design - Development through a Model-based Systems Approach

    DEFF Research Database (Denmark)

    Conte, Elisa

    The ‘consumer oriented chemicals based products’ such as shampoos, sunscreens, insect repellents are used everyday by millions of people. They are structured products, constituted of numerous chemicals. This complexity gives the reason for which mainly experimental techniques are still employed...

  17. Integrating textual and model-based process descriptions for comprehensive process search

    NARCIS (Netherlands)

    Leopold, Henrik; van der Aa, Han; Pittke, Fabian; Raffel, Manuel; Mendling, Jan; Reijers, Hajo A.


    Documenting business processes using process models is common practice in many organizations. However, not all process information is best captured in process models. Hence, many organizations complement these models with textual descriptions that specify additional details. The problem with this

  18. An Integrated Risk Index Model Based on Hierarchical Fuzzy Logic for Underground Risk Assessment

    Directory of Open Access Journals (Sweden)

    Muhammad Fayaz


    Full Text Available Available space in congested cities is getting scarce due to growing urbanization in the recent past. The utilization of underground space is considered as a solution to the limited space in smart cities. The numbers of underground facilities are growing day by day in the developing world. Typical underground facilities include the transit subway, parking lots, electric lines, water supply and sewer lines. The likelihood of the occurrence of accidents due to underground facilities is a random phenomenon. To avoid any accidental loss, a risk assessment method is required to conduct the continuous risk assessment and report any abnormality before it happens. In this paper, we have proposed a hierarchical fuzzy inference based model for under-ground risk assessment. The proposed hierarchical fuzzy inference architecture reduces the total number of rules from the rule base. Rule reduction is important because the curse of dimensionality damages the transparency and interpretation as it is very tough to understand and justify hundreds or thousands of fuzzy rules. The computation time also increases as rules increase. The proposed model takes 175 rules having eight input parameters to compute the risk index, and the conventional fuzzy logic requires 390,625 rules, having the same number of input parameters to compute risk index. Hence, the proposed model significantly reduces the curse of dimensionality. Rule design for fuzzy logic is also a tedious task. In this paper, we have also introduced new rule schemes, namely maximum rule-based and average rule-based; both schemes can be used interchangeably according to the logic needed for rule design. The experimental results show that the proposed method is a virtuous choice for risk index calculation where the numbers of variables are greater.

  19. An Integrated Framework for Model-Based Distributed Diagnosis and Prognosis (United States)


    0 : t) denotes all measurements observed up to time t. The goal of prognosis is to determine the end of (use- ful) life ( EOL ) of a system, and/or its...remaining useful life (RUL). For a given fault, f , using the fault estimate, p(xf (t),θf (t)|y(0 : t)), a probability distribution of EOL , p(EOLf ( stochas- tic, EOL /RUL are random variables and we represent them by probability distributions. The acceptable behavior of the system is expressed

  20. Two-vehicle injury severity models based on integration of pavement management and traffic engineering factors. (United States)

    Jiang, Ximiao; Huang, Baoshan; Yan, Xuedong; Zaretzki, Russell L; Richards, Stephen


    The severity of traffic-related injuries has been studied by many researchers in recent decades. However, the evaluation of many factors is still in dispute and, until this point, few studies have taken into account pavement management factors as points of interest. The objective of this article is to evaluate the combined influences of pavement management factors and traditional traffic engineering factors on the injury severity of 2-vehicle crashes. This study examines 2-vehicle rear-end, sideswipe, and angle collisions that occurred on Tennessee state routes from 2004 to 2008. Both the traditional ordered probit (OP) model and Bayesian ordered probit (BOP) model with weak informative prior were fitted for each collision type. The performances of these models were evaluated based on the parameter estimates and deviances. The results indicated that pavement management factors played identical roles in all 3 collision types. Pavement serviceability produces significant positive effects on the severity of injuries. The pavement distress index (PDI), rutting depth (RD), and rutting depth difference between right and left wheels (RD_df) were not significant in any of these 3 collision types. The effects of traffic engineering factors varied across collision types, except that a few were consistently significant in all 3 collision types, such as annual average daily traffic (AADT), rural-urban location, speed limit, peaking hour, and light condition. The findings of this study indicated that improved pavement quality does not necessarily lessen the severity of injuries when a 2-vehicle crash occurs. The effects of traffic engineering factors are not universal but vary by the type of crash. The study also found that the BOP model with a weak informative prior can be used as an alternative but was not superior to the traditional OP model in terms of overall performance.