Quality of Life through Quality of Information J. Mantas et al. (Eds.) IOS Press, 2012 © 2012 European Federation for Medical Informatics and IOS Press. All rights reserved. doi:10.3233/978-1-61499-101-4-497
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A Standardized Middleware as the core of a Telemonitoring European Project Fabio VERGARIb,1, Roberta GAZZARATAa, Francesco MORANDIb, Viola PARODIc, Simone NASOc, Alessandra AREZZAc, Tulio SALMON CINOTTIb and Mauro GIACOMINIa a Department of Communication, Computer and System Sciences (DIST), University of Genoa, Genoa, Italy b Advanced Research Center on Electronic Systems for Information and Communication Technologies E. De Castro (ARCES), University of Bologna, Bologna, Italy c Infinity Technology Solutions (ITS), Genoa, Italy
Abstract. In order to develop smart and innovative solutions which are able to realize the concept of care continuum, the use of a number of different multiple devices, based on heterogeneous technologies, is necessary. In this complex context it is important to study and design systems whose architecture ensure the interoperability between devices and service. A standardized middleware which is able to guarantee this important requirement within the European Project CHIRON, is presented in this article. Keywords. Interoperability, HL7 v3 CDA R2, Smart Space.
Introduction Over recent years demographic and socio-economic challenges have highlighted the need for change in healthcare; the population is ageing, life expectancy is increasing, the number of people with chronic diseases is growing and healthcare and social costs are exploding [1-2]. In this complex context, ICT provides biomedical engineering with the instruments to research, project and develop smart and innovative solutions which are able to renovate healthcare practice. One category of these solutions is represented by telemonitoring systems which can enlarge the boundaries of healthcare and promote the concept of continuum care. For example HeartCycle [3], a 2008 European Project, was aimed at improving the quality of care of patients affected by cardiac diseases by developing systems for health condition monitoring at home and involving the patient in the daily management of their disease. Other systems are aimed at compensating for the loss of physical and/or cognitive abilities by helping persons with disabilities and aging citizens to augment their autonomy (EASY LINE+ [4], IWARD [5]). This introduction points out just some of the most recent projects but there is a constant underlying common aspect present in all of them: the amount of multiple different devices, based on heterogeneous technologies, and the necessity for 1
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integration according to the specific user and environmental needs. Therefore, the main aim of the European Project CHIRON [6] is to design a reference architecture for personal healthcare which will ensure the interoperability between heterogeneous devices and services, a reliable and secure patient data management and a seamless integration with the clinical workflow. Our work in this project consists in studying a standardized solution to solve all the problems related to physic, syntactic and semantic interoperability and then to design and develop a middleware based on the Health Level Seven version 3 (HL7 v3) standard. The solution must allow a standardized information transmission between the User and the Medical Plane and provide the ability to reactively and automatically generate and communicate alarms conditions when the patient health state is critical. The User Plane is concerned with the set of devices and instruments used to monitor the patient and the local feedback; the Medical Plane represents interactions by and with the doctors (assessment of clinical data, diagnosis, treatment planning and execution, and feedback to the patient).
1. Methods One of the main objectives of the CHIRON project is to define a standard based framework to allow information transmission between the User and the Medical Planes; this solution must be able to generate and communicate the alarm conditions based on the personalized patient criteria by processing vital signals and context (activity and environmental information) acquired from the heterogeneous devices. Consequently, the first priority was to identify a common standard for medical information exchange between the CHIRON architecture layers and a solution providing interoperability with applications and devices used to monitor the patients. Therefore, two different solutions were combined, which together allowed the projection and development of a telemonitoring solution completely interoperable from the physic, syntactic and semantic point of view. The Smart Space (SS) solution, which was developed in SOFIA [7] project, was adopted in order to ensure information interoperability concerning the collection of sensor data between heterogeneous devices and instruments. To solve syntactic and semantic interoperability in information transmission the HL7 Version 3 Clinical Document Architecture (CDA) Release 2 (R2) was utilised. 1.1. Smart Space The Smart Space solution guarantees information (or semantic) interoperability, that is the shared understanding of information significance. The SS information is about entities existing in the physical environment, that is, the users, the objects surrounding them, the devices used, or about the environment itself. This multi domain solution in CHIRON architecture could be the possible core of the User Plane. In this scenario every patient has his personal Smart Space that manages information collected from heterogeneous devices together with the user profile; thanks to its publish/subscribe mechanism, the solution is responsible also for event/notification. SS architecture has two main actors: the semantic information broker (SIB) and the knowledge processor (KP). The SIB is a digital entity where relevant real-world information is stored and kept up-to-date. The information model is a directed labeled graph corresponding to a set of Resource Description Framework (RDF a basic semantic web standard) triples.
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The information semantics is specified by ontologies defined in OWL (Web Ontology Language). The KPs are software components interacting with the SIB and producing and/or consuming data. The legacy adapters are KPs that enable legacy SS-unaware devices to exchange information with the SIB (Figure 1). A KP exchanges data through a simple protocol named smart space access protocol (SSAP), an application layer protocol based on XML (eXtensible Markup Language). The SSAP defines a simple set of messages (join, insert, remove, update, query, subscribe, and leave) that can be used over multiple connectivity mechanisms [8]. KPs uses SSAP API developed in different programming languages (C#, C, Python, Java, PHP) while SS runs on a Linux based system.
Figure 1. Smart Space
1.2. HL7 v3 Clinical Document Architecture Release 2 Clinical Document Architecture Release 2 is a document markup standard developed by HL7, encoded in markup languages as XML or RDF, that specifies the structure and semantics of a clinical document for the purpose of exchange. The HL7 CDA R2 provides an object model in order to represent a technical diagram of the CDA specification and structure. The basic structure of the CDA Release 2 is formed by two parts fully HL7 v3 RIM (Reference Information Model) derived: a header and a body. The header’s purpose is to set the context for the document as a whole: to enable clinical document exchange across and within institutions, to facilitate clinical document management and to facilitate compilation of an individual patient’s clinical documents into a lifetime electronic patient record. The other part, the body, contains the clinical report and it can be either an unstructured blob or can be comprised of structured markup. In the second case, the body is divided up into recursively nestable document sections. Each section contains a single ‘‘narrative block’’, any number of CDA entries and external references (such as some other image, procedure, or clinical document). The ‘‘narrative block’’ represents content to be rendered, which is expressed in human language. Every section can contain a clinical statement which is one of the following: an observation, a substance administration, a supply or a procedure. Each clinical statement in turn can relate to another one with a semantic relationship (e.g., cause, component, reason). Data types used in the CDA define the structural format of the data carried within an attribute, and influences the set of allowable values an attribute may assume. Several CDA components are designed to carry concepts drawn from the HL7-defined or HL7recognized coding systems such as LOINC (Logical Observation Identifiers Names and Codes) or SNOMED CT (Systematized Nomenclature of Medicine Clinical Terms) [9].
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2. Results To design and develop an interoperable exchange of information between the User and the Medical Plane, the two solutions explained previously were combined: Smart Space and the HL7 v3 CDA. This combined solution benefits of the SS advantages (publish/subscribe mechanism and information interoperability) adding to the HL7 standardization value. This prototype was realized through an ASP.NET Web Service (WS) which provides a set of functionalities for the exchange of messages whose types and formats are based on the adopted medical standard, HL7 v3 CDA R2. The WS has the middleware role which allows a simple and standardized communication among heterogeneous actors The functionalities exposed by the WS are; RegisterNewPatient, SendPatientCDA, SendAlarm, UpdatePatientCDA. Here below are presented different storyboards as implemented use cases, based on the previously explained solution (Figure 2).
Figure 2. Storyboards
2.1. First storyboard – Settings of alarms safety thresholds: from the Medical Plane to the User Plane When a patient is discharged from the hospital, he/she will be monitored at home by our SS system. The Medical Plane sends a new CDA document containing the new patient data to the middleware. This one provides a service which is able to register a new patient in the middleware repository: RegisterNewPatient. Another service receives the Patient CDA from the Medical Plane and extracts observations with thresholds values related to the Patient and sends them to the User Plane within a HL7 v3 message: SendPatientCDA. 2.2. Second storyboard – Alarms communications from User to Medical Plane The User Plane monitors a patient at home. An alarm is automatically generated inside the SS when the measured values are outside the allowed ranges. This alarm is sent by the SS from the User Plane to the middleware in the form of a HL7 alarm message. The middleware extracts the required information from the HL7 alarm message and sends the new observation to the Medical Plane. These actions are realized by the SendAlarm service.
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2.3. Third storyboard – Updating the CDA The Medical Plane receives the alarm from the User Plane through the middleware. It needs the old CDA in order to update it with new data. The Medical Plane sends a notification via a HL7 message to the middleware through a Web Service: UpdatePatientCDA. This service queries the old CDA from the repository, updates it with new data and sends it back to the CDA to the Medical Plane.
3. Discussion The CHIRON project intends to design a reference architecture for personal healthcare, ensuring interoperability between heterogeneous devices and services, as well as a reliable and secure patient data management and a seamless integration with the clinical workflow. To ensure correct and complete communication between different layers and devices, the Service Oriented Architecture (SOA) paradigm has been adopted as support for the information communication. In this work we presented our fully functional prototype (middleware) enabling the out of hospital monitoring of a patient by the Medical Plane. This solution has been accepted as the middleware of the CHIRON project thanks to its flexibility and its capability to react to an event. The solution will be tested on the field during the project trial.
Acknowledgment This work was developed within CHIRON and SOFIA projects of the European Joint Undertaking on Embedded Systems ARTEMIS and are co-funded by the EU and by National Authorities (CHIRON: GA n. 100228; SOFIA: GA n. 100017).
References [1] Population Project EUROPOP, http://epp.eurostat.ec.europa.eu/. [2] Institute for Healthcare Improvement (IHI), http://www.ihi.org/. [3] Maglaveras Nikolaos, and Reiter Harald. “Towards Closed-Loop Personal Health Systems in Cardiology:The HeartCycle Approach”, 33rd Annual International IEEE EMBS Conference, Boston Marriott Copley Place, Boston, MA, USA; August 2011. [4] Casas R., Blasco Marín R., et al. “User Modelling in Ambient Intelligence for Elderly and Disabled People”, Computers Helping People with Special Needs, 5105, pp. 114-122. [5] Díaz U., Laskibar I., et al. “Preferences of Healthcare staff in the Way of Interacting with Robots Depending on their Prior Knowledge of ICTs: Findings from IWARD Project”. Poster presented in the 7th International Conference On Smart Homes and health Telematics (ICOST 2009), 1st-3rd July 2009. Proceedings published in M. Mokhtari et al. (Eds.): ICOST 2009, LNCS 5597, pp. 282–285, 2009. [6] http://www.chiron-project.eu/ [7] http://www.sofia-project.eu/ [8] Vergari F., Bartolini S., et al. (2010). "A Smart Space Application to Dynamically Relate Medical and Environmental Information. Proceedings Design, Automation & Test in Europe". Dresden, Germany 1542 - 1547. [9] Dolin R. H., L. Alschuler, et al. (2006). “HL7 Clinical Document Architecture, Release 2.” J Am Med Inform Assoc 13(1): 30-39.
