Top of page. Abu Dhabi Case study Encouraging Foreign Investment. The UAE is home to Sovereign Wealth Funds SWFs that together manage over an estimated USD1. The rickroll stunt was just one hack at the security conference DEF CON, which ran a threeday Voting Machine Hacking Village to test the security of various machines. Vol. 7, No. 3, May, 2004. Mathematical and Natural Sciences. Study on Bilinear Scheme and Application to Threedimensional Convective Equation Itaru Hataue and Yosuke. Technology and Science News ABC News. Innovation made by Talents INVENSITY Gmb. HMore and more medical devices depend on software. Therefore the number of reports about problems caused by software is rising dramatically Bf. Ar. M 2. 00. 7. It is necessary to develop software which is error free and safe from the beginning as well as to consider all risks and hazards. A structured and traceable development is essential, because even the smallest mistake during the development of medical devices can result in fatal consequences. For the software development there are no safety instructions and the software for medical devices can be a very complex system. The Assurance Case is used to structure and divide this complex system in parts that are easier to handle. The Assurance Case is a documented line of evidence method which uses a convincing and valid argument to proof the accumulation of critical claims by significant evidences. The structured argumentation and evidence support the reliability of the main claim e. The device is safe. If the main claim refers to the safety of the device like in the given example the Assurance Case can be called Safety Case. Assurance Cases were initially used in the nuclear technology, aerospace engineering and the defense industry where they are mainly used as Safety Cases. The Assurance Case is sub divided in three main categories which are characterized by symbols Claims. The claims have to be in a specific context, which can be in relation to the environment, application, behavior, risks or hazards. The main claim The device is safe, is on the top level. Sub claims which are built hierarchically can characterize the claim further and have to be argued and proven as well. Arguments. Arguments are the link between claim and proof. There are three kinds of arguments Deterministic predetermined rules are applied for a truefalse claim e. Probabilistic quantitative statistical reasoning in order to establish a numerical level e. Qualitative observation of rules that have an indirect link to the desired feature e. QMS standards. Evidence. Evidence can be based on product analysis, on development processes and reliability testing for a new design, field experience for an established design or product review. Assurance Cases are illustrated as diagrams with specific symbols. Like mentioned above, every symbol is assigned to a certain level. This graphical illustration is called Goal Structuring Notation GSN T. Kelly, 1. 99. 8. Thereby goal is used simultaneous for claim. In its simplest form the Assurance Case consists of the three main levels The advantage over other procedure models is its easy traceability due to the graphical illustration. This kind of graphical demonstration can refer to the principle of the software modeling language UML unified modeling language or Sys. ML system modeling language respectively. UML is a standardized graphic modeling language which is used for graphic construction and specification of software parts, but also other types of systems can be represented. Notations which are language elements that are demonstrated as symbols are used. An advanced modeling language for more general systems is Sys. ML, which is more flexible and variable in its appearance than UML. It can be used for analysis, specification, verification and validation of many systems. Next figure shows an example of a typical structure of an Assurance Case Assurance Case application for medical devices. In the field of medical technology the Assurance Case has been developed for generic infusion pumps GIP Figure 3. GIPs belong to the risk class II and III, depending on their usage. Therefore they have very high security and safety requirements. In the US alone, 5. January 2. 00. 5 and December 2. FDA, 2. 01. 0. Due to this enormous error rate the FDA has chosen the Assurance Case as a process model in order to minimize the risk and afford better safety quality. The FDA report 5. Working Group Preliminary Report and Recommendations released in August 2. Assurance Case for premarket notification 5. FDA division CDRH Center for Devices and Radiological Health. 5. II products, which have to be tested by a premarket review before market launch. The CDRH expects a better traceability of the development and safety examination due to application of the Assurance Cases and therefore a faster approval time. In the case of infusion pumps belonging to class II all risks and hazards as well as safety implementation have been described and demonstrated for Assurance Cases. For other medical devices the CDRH has to determine the conditions how to develop the Assurance Case and what is needed to guarantee a good comparability and simplified management. The guidelines have to contain detailed product descriptions of all medical devices with requested approvals and also user descriptions. Furthermore, all modifications since the first release have to be described again. Additional the CDRH has to tutor its reviewers and managers for evaluation of Assurance Cases. This shows some of the challenges for the introduction of Assurance Cases. The Assurance Case refers to very complex systems and the demonstration of evidence is very work intensive. Further it is hard to generalize or reuse the case for different medical devices. The creation of the Assurance Cases and its handling is very labor and time intensive, but on the other hand safety and elimination of errors are the greatest challenges and should have highest priority. It has to be considered that recalls and error reports are not only cost intensive, but also cause damage of the companys image. Assurance Cases are an efficient process model, which in the future can speed up the process of approval and assure highest safety standards at the same time. INVENSITY would like to support and advice you in introduction and implementation of Assurance Cases for your medical device and questions on functional safety. Example of an Assurance Case. The claim described on the top level is The GIP is safe for the patient C1. A strategy that results from this assumption could be to argue all risks and hazards S1. This strategy can be considered in different contexts, for example risks due to user errors by programming Ct. Ct. 4 or wrong application to patients Ct. Ct. 3. Due to the different sub claims and contexts, more and more specific sub claims C1. On the second level the GIP is categorized in different hazards operational hazard, environment hazards, electrical hazards, hardware hazards, software hazards, mechanical hazards, biological and chemicals hazards as well as use hazards. Those categories divide in more detailed sub claims. All sub claims have to be proven E1 1. The evidence can be performed in different ways user testing E1. E1. 3 or it can be addressed to documentation E3.
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