Smart Flow - Extendable Event-Based Middleware

世界各地的医疗保健提供商正在开发电子解决方案，以改善患者护理并降低成本。这是一项复杂而具有挑战性的工作：此类系统需要集成许多分布式和异构应用程序，并在事件发生时协调广泛分布的操作，同时不损害患者安全和隐私。中间件软件是连接这些不同应用程序的管道，然而商业现成的中间件无法适应医疗领域的特殊需求：例如，医疗保健系统必须审计对患者记录的所有访问，因为它们流经网络，但审计数据本身不能危及机密性。这种机密审计目前不受支持，但最好在中间件中执行。类似地，血液科需要检测事件的模式：发送到电子病历的异常血液结果，如果没有及时确认接收，将表明网络故障或其他延迟，血液科将向病房发出警告。对此的中间件支持还不存在，但是对于有效的解决方案来说是至关重要的。支持这种新型中间件功能的一个主要挑战是，没有一组服务可以覆盖所有应用程序需求。相反，中间件功能必须随着新应用程序的添加而发展。本提案的重点是通过研究可扩展的、基于事件的中间件体系结构Smart Flow来解决这一挑战，Smart Flow可以集成异构系统，并提供动态管理中间件扩展的框架。它将涵盖医疗领域的常见需求，如隐私、审计和事件模式检测，而不会牺牲效率。应用程序通过使用事件驱动的方法发送和接收消息来协调所有活动。消息由一组扩展指定的Smart Flow节点处理。扩展可能负责在医院部门之间智能地路由消息、审计消息流、对患者数据应用访问控制检查以及加密患者数据以保持机密性。通过将此功能推入智能中间件层，医疗系统中的所有应用程序都可以使用这些服务，从而简化了应用程序的设计和部署，并提高了性能。当有新的应用程序（和需求）的新部门加入系统时，扩展可以以安全一致的方式动态添加到Smart Flow节点。医疗系统是松散耦合的，既有直接的、同步的交互（例如，查找病人的血液结果），也有间接的、异步的连接（例如，以电子方式向癌症登记处发送每月一批的病理报告）。为了描述中间件及其配置，我们将设计一种形式，它可以捕获高级中间件特性、它们分解为低级Smart Flow扩展，以及扩展之间的依赖关系和排斥关系。这将允许每个应用程序指定它需要的扩展。动态重新配置将允许Smart Flow支持随时间变化的需求。我们还将把事件驱动的方法扩展到中间件本身的内部工作。每个Smart Flow节点将使用基于事件的内核以显式消息的形式驱动扩展之间的信息流。这种方法的优点是，现有的中间件系统可以通过将它们视为特别丰富的扩展来与Smart Flow集成。这意味着Smart Flow可以用一种简单、一致和易于配置的方式增强现有中间件的额外功能。明确信息流还可以通过识别和规范内部消息的使用来增强安全性。

Healthcare providers world-wide are developing electronic solutions to improve patient care and reduce costs. This is a complex and challenging endeavour: such systems need to integrate many distributed and heterogeneous applications and coordinate widely distributed operations as events occur, without compromising patient safety and privacy. Middleware software is the plumbing that interconnects these various applications, however commercial off-the-shelf middleware is unable to adapt to the special requirements of the medical domain: e.g. a healthcare system must audit all access to a patient's records as they flow through the network and yet the audit data must not itself compromise confidentiality. This kind of confidential audit is not currently supported, yet would be best performed within middleware.Similarly, a haematology department would need to detect patterns of events: abnormal blood results sent to the electronic patient notes but with no timely confirmation of receipt would signal a network failure or other delay, and haematology would warn the ward. Middleware support for this does not exist, yet would be vital for an efficient solution. A major challenge in supporting such novel middleware functionality is that there is no single set of services that covers all application requirements. Instead, middleware functionality must evolve as new applications are added.The focus of this proposal is to address this challenge with research into an extendable, event-based middleware architecture, Smart Flow, which can integrate heterogeneous systems and provide a framework for dynamically managing middleware extensions. It will cover common requirements from medical domains, such as privacy, auditing and event pattern detection, without sacrificing efficiency.Applications coordinate all activity by sending and receiving messages using an event-driven approach. Messages are handled by Smart Flow nodes, as dictated by a set of extensions. Extensions may be responsible for intelligently routing messages between hospital departments, auditing message flow, applying access control checks to patient data and encrypting patient data to preserve confidentiality. By pushing this functionality into an intelligent middleware layer, all applications in a medical system can use these services, thus simplifying application design and deployment and improving performance. As new departments with new applications (and requirements) join the system, extensions can be added dynamically to Smart Flow nodes in a safe and consistent manner.Medical systems are loosely coupled, with a mixture of direct, synchronous interactions (e.g. looking up a patient's blood results), and indirect, asynchronous connections (e.g. a monthly batch of pathology reports, sent electronically to a cancer registry). To describe a middleware and its configurations, we will devise a formalism that can capture high-level middleware features, their decomposition into lower-level Smart Flow extensions, and the dependencies and exclusion relationships between extensions. This will let each application specify which extensions it needs. Dynamic reconfiguration will allow Smart Flow to support requirements that change over time.We will also extend the event-driven approach to the inner workings of the middleware itself. Each Smart Flow node will use an event-based kernel to drive the flow of information between extensions, in the form of explicit messages. The advantage of this approach is that existing middleware systems can be integrated with Smart Flow by treating them as particularly rich extensions. This means that Smart Flow can enhance existing middleware with extra features in a way that is straightforward, consistent and easily configured. Making information flow explicit will also enhance security, by identifying and regulating the use of internal messages.