Tom H. F. Broens

Context-Aware, Ontology-Based Service Discovery

Service discovery is a process of locating, or discovering, one or more documents, that describe a particular service. Most of the current service discovery approaches perform syntactic matching, that is, they retrieve services descriptions that contain particular keywords from the user’s query. This often leads to poor discovery results, because the keywords in the query can be semantically similar but syntactically different, or syntactically similar but semantically different from the terms in a service description. Another drawback of the existing service discovery mechanisms is that the query-service matching score is calculated taking into account only the keywords from the user’s query and the terms in the service descriptions. Thus, regardless of the context of the service user and the context of the services providers, the same list of results is returned in response to a particular query. This paper presents a novel approach for service discovery that uses ontologies to capture the semantics of the user’s query, of the services and of the contextual information that is considered relevant in the matching process.

Context aware body area networks for telemedicine

A Body Area Network (BAN) is a body worn system which provides the user with a set of mobile services. A BAN incorporates a set of devices (eg. mp3 player, video camera, speakers, microphone, head-up display, positioning device, sensors, actuators). A BAN service platform for mobile healthcare and several health BANs targetting different clinical applications have been developed at the University of Twente. Each specialization of the BAN is equipped with a certain set of devices and associated application components, as appropriate to the clinical application. Different kinds of clinical data may be captured, transmitted and displayed, including text, numeric values, images and multiple biosignal streams. Timely processing and transmission of such multimedia clinical data in a distributed mobile environment requires smart strategies. Here we present one approach to designing smart distributed applications to deal with multimedia BAN data; namely the context awareness approach developed in the FREEBAND AWARENESS project.

Context-aware QoS provisioning in an m-health service platform

Inevitably, healthcare goes mobile. Recently developed mobile healthcare (i.e., m-health) services allow healthcare professionals to monitor mobile patients vital signs and provide feedback to this patient anywhere at any time. Due to the nature of current supporting mobile service platforms, m-health services are delivered with a best-effort, i.e., there are no guarantees on the delivered Quality of Service (QoS). In this paper, we argue that the use of context information in an m-health service platform improves the delivered QoS. We give a first attempt to merge context information with a QoS-aware mobile service platform in the m-health services domain. We illustrate this with an epilepsy tele-monitoring scenario.

Patient-oriented Computerized Clinical Guidelines for Mobile Decision Support in Gestational Diabetes

Background: The risks associated with gestational diabetes (GD) can be reduced with an active treatment able to improve glycemic control. Advances in mobile health can provide new patient-centric models for GD to create personalized health care services, increase patient independence and improve patients’ self-management capabilities, and potentially improve their treatment compliance. In these models, decision-support functions play an essential role. Methods: The telemedicine system MobiGuide provides personalized medical decision support for GD patients that is based on computerized clinical guidelines and adapted to a mobile environment. The patient’s access to the system is supported by a smartphone-based application that enhances the efficiency and ease of use of the system. We formalized the GD guideline into a computer-interpretable guideline (CIG). Results: We identified several workflows that provide decision-support functionalities to patients and 4 types of personalized advice to be delivered through a mobile application at home, which is a preliminary step to providing decision-support tools in a telemedicine system: (1) therapy, to help patients to comply with medical prescriptions; (2) monitoring, to help patients to comply with monitoring instructions; (3) clinical assessment, to inform patients about their health conditions; and (4) upcoming events, to deal with patients’ personal context or special events. Conclusions: The whole process to specify patient-oriented decision support functionalities ensures that it is based on the knowledge contained in the GD clinical guideline and thus follows evidence-based recommendations but at the same time is patient-oriented, which could enhance clinical outcomes and patients’ acceptance of the whole system.

Service platform for rapid development and deployment of context-aware, mobile applications

In this paper we present a Web services-based platform that facilitates and speeds up the development and deployment of context-aware, integrated mobile speech and data applications. The platform is capable of handling different types of context and offers sophisticated personalization mechanisms. To illustrate the usefulness of the platform and to validate the claim that cross-platform application development, in particular mobile, context-aware applications is easier and faster with Web services technologies, we present a demonstration application. It serves tourists with interesting information and services in their specific context, and contributes to the achievement of their current goals. Finally, we present a number of problems that we experienced in the implementation process as well as the feedback that we received from real users who tested our application.

Dynamic Context Bindings in Pervasive Middleware

Context-awareness (CA) enables the development of personalized pervasive services. Current context-aware infrastructures focus on middleware solutions to support acquisition, usage and management of context. However, using context requires the CA application to create a binding between itself and one or more context producing entities. Creating this binding is the responsibility of the CA application developer, which is often an extensive manual task. The ad hoc availability of context-producing entities further complicates this responsibility. This paper proposes an application infrastructure, coined CACI, which offers a binding transparency to support rapid development of CA applications. CACI enables developers to specify context requirements at a high abstraction level using a declarative binding language. CACI also provides the creation and maintenance of bindings to context producing entities based on such specifications. This paper discusses the design and implementation of CACI. Additionally, it discusses the validation of CACI using a pervasive healthcare scenario

Use of the virtual medical record data model for communication among components of a distributed decision-support system

MobiGuide is a distributed decision-support system (DSS) that provides decision support for patients and physicians. Patients receive support using a light-weight Smartphone DSS linked to data arriving from wearable monitoring devices and physicians receive support via a web interface connected to a backend DSS that has access to an integrated personal health record (PHR) that stores hospital EMR data, monitoring data, and recommendations provided for the patient by the DSSs. The patient data model used by the PHR and by all the system components that interact in a service-oriented architecture is based on HL7s virtual medical record (vMR) model. We describe how we used and extended the vMR model to support communication between the system components for the complex workflow needed to support guidance of patients any time everywhere.

Supporting the developers of context-aware mobile telemedicine applications

Telemedicine, which is defined as providing healthcare and sharing of medical knowledge over distance using telecommunication means, is a promising approach to improve and enhance the healthcare provisioning process. However, only recently, technology has evolved (i.e. miniaturization of high power mobile devices that can use high bandwidth mobile communication mechanisms) such that feasible advanced telemedicine applications can be developed. Current telemedicine systems offer proprietary solutions that are used in specific disease domains. For the acceptation, rapid development and introduction of novel and advanced telemedicine applications, there is a need for architectural mechanisms that supports developers in rapidly developing such telemedicine applications. The research discussed in this paper, focuses on the development of such mechanisms.

Application of a conceptual framework for the modelling and execution of clinical guidelines as networks of concurrent processes

We present a conceptual framework for modelling clinical guidelines as networks of concurrent processes. This enables the guideline to be partitioned and distributed at run-time across a knowledge-based telemedicine system, which is distributed by definition but whose exact physical configuration can only be determined after design-time by considering, amongst other factors, the individual patients needs. The framework was applied to model a clinical guideline for gestational diabetes mellitus and to derive a prototype that executes the guideline on a smartphone. The framework is shown to support the full development trajectory of a decision support system, including analysis, design and implementation.

Dynamic context bindings - Infrastructural support for context-aware applications

The world is increasingly equipped with high-capacity, interconnected, mobile and embedded computing devices. Context-awareness provides an attractive approach to personalize applications such that they better suit the user’s needs in this rich computing environment. Context-aware applications use context information, offered by context sources, to adapt their behavior to the situation at hand. The exchange of context information requires an association between a context consuming context-aware application and suitable context producing context sources. We call these associations ‘context bindings’. Developing context-aware applications is complex due to some intrinsic characteristics of context sources. Firstly, context sources are distributed. Consequently, creating a context binding requires some form of discovery and selection of context sources. Secondly, context sources are arbitrary available during the life-span of the application. This makes a binding hard to maintain. Finally, context sources offer context information with a fluctuating quality. This makes a binding possibly unsuitable for the application. Currently, developers need to spend considerable effort to develop application code to create and maintain required context bindings, which can deal with these complexities. This thesis provides insights in the generic characteristics of contextaware applications and their development process. We propose an abstraction, called the Context Binding Transparency. This transparency has as goal to mask the complexities of creating and maintaining context bindings for the application developer. In this way, we facilitate the development process of context-aware applications. The responsibility for creating and maintaining context bindings is relieved from the application developer and is shifted to a context binding infrastructure. This enables application developers to focus on the development of primary application logic rather than the logic needed to create and maintain context bindings. The application developer interacts with the context binding infrastructure using context retrieval and publishing services, and a context requirement specification language. This language enables application developers to specify their requirement at a high level of abstraction rather than in programming code. In this thesis, we propose a realization of such a context requirement specification language, coined the Context Binding Description Language (CBDL). This language is developed to be generic for a broad range of context-aware applications. Additionally, we propose a realization of a context binding infrastructure called the Context-Aware Component Infrastructure (CACI). This infrastructure realizes a context binding transparency and is composed of a context binding mechanism and a context discovery interoperability mechanism. The context binding mechanism uses CBDL documents, specified by the application developers, to create and maintain context bindings on behalf of the application. The process of creating a binding consists of discovery of context sources at available context discovery mechanisms, selection of suitable context sources, establishment of a binding of the application to these context sources, and maintenance of this binding. Maintenance of a context binding includes re-binding to other suitable context sources in case of lost or (re-)appearing context sources and fluctuating quality of context. This thesis gives an example of a possible rebinding algorithm. The context discovery interoperability mechanism enables contextaware applications to interoperate transparently with different context discovery mechanisms available in the application environment. The goal of the interoperability mechanism is to hide the heterogeneity and fluctuating availability of context discovery mechanisms for context-aware applications. The context discovery interoperability mechanism is a supporting mechanism for the context binding mechanism. It can also be used independently by context-aware applications that do not leverage from the context binding mechanism. We have created a proof-of-concept prototype of CACI, using the OSGi component framework. The prototype includes implementations of the context binding mechanism and the context discovery interoperability mechanism. Evaluation of the proposed context binding transparency and infrastructure consists of a user survey and a comparison on the development effort and software quality of a Telemedicine case implementation with and without CACI. The survey indicated a general interest of possible users in the features of the context binding transparency. The case implementations indicated a possible improvement in the development process of higher quality context-aware applications when using a context binding infrastructure. This research stresses that the availability of context information and the quality of this information highly influences the development of contextaware applications. By using a middleware infrastructure to support the creation and maintenance of context bindings, the development of higher quality context-aware applications can be simplified.