The role of W3C is to establish recommendations for generic technologies on the World Wide Web that operate between the underlying transport layer and the applications specific to individual industrial sectors. Practitioners active in industrial sectors will need to establish those applications, but they also need to ensure that the generic technology on which they are built provides them with the opportunities they require and does not constrain them so much as to prevent them from producing what they need for their own industrial sector. To do this practitioners in industrial sectors other than information technology need to be aware of and involved in the development of future recommendations at the generic level that W3C operates. Here are described some of the W3C technologies on which applications in the health and medicine sector are based.
The information technology applications in the health and medicine sector where W3C have a role address content management and messaging; that is, the searching and presentation of patient information and disease information, and the transmission of messages to both humans and computers.
Ten years ago medical records were for the most part paper based, parochial, and reflected the whims of local providers. Communication between providers in this system was invariably done using 'referral letters'. XML promises a means of providing flexible, incremental employment of electronic systems, and also provides a means for easy communication between disparate binary electronic systems. Ultimately and ideally the whole record system will be based on a non-proprietary mark-up language (XML), but till that day comes XML can still be useful and used as an incremental replacement for existing systems.
Several organisations in the health sector have produced standards for patient records using XML. The most visible of these is Health Level 7 (HL7) which is a health sector IT standards body for SGML/XML. HL7 use XML as the syntax for HL7 patient record architecture as an exchange mechanism for electronic documents, and for the HL7 messages to request and send healthcare information.
Such XML patient record applications are neither at the research stage, nor require the loss of legacy information as Andrew Roberts FRCS DM a Consultant Orthopaedic Surgeon in the UK has stated "In Oswestry we have a number of legacy systems which we are not able to replace with openHL7 aware products. XML 's ability to capture the structured output of these systems and output them to a repository or even another non-compliant system is unique in it's flexibility." Such systems are now being widely adopted in hospitals, for example, Poole hospital, in the UK, have implemented an electronic patient record using an XML repository, which now stands at 12 million XML documents.
XML is not limited to patient records, but can also be used to represent each document in the processing of tests such as blood analysis, and link those back to the patient record. With automation and centralization of blood analysis, the cost of actual analysis has been reduced to a few cents rather than several dollars. However the cost of processing, tracking, and documenting a test has continued to climb, and now constitutes 95+% of the cost of the test. An XML based system can simplify the system considerably. All the paper work is automatically generated from the original order entry, and an Intranet allows automatic tracking of the results. Furthermore simple programs allow automatic triage of the result, communication between provider nodes using different electronic systems, and in the many cases the follow up visit can be aborted.
Once an application is built on XML such as a patient record standard, then a wide range of other standard, non-proprietary tools can be brought to bear such as using XML Query to query the repository and XSLT to transform the XML documents for presentation as web pages in XHTML, or even as graphical images using SVG, both of which can be viewed in web browsers on many devices.
The separation of content from rendition that XML provides allows a single XML source document to be presented in many different ways on different devices. Doctors and other medical professionals are not always sitting in front of a computer, and even if they do, they may not necessarily have time to search through Web sites and databases. Clearly, what is needed is a centralised source of information so that all doctors can have the same access to consistent medical data. Voice solutions work here. One way to create these solutions is with VoiceXML, a W3C recommendation for developing voice applications using XML.
Through VoiceXML and outbound calling notifications, information can be pushed to individuals via the telephone. The phone works because we are trained to pick it up. When the phone rings, we answer it. In an emergency, people do not always have access to a computer, but they almost always have access to at least a mobile phone. There are 1.5 billion in-service telephones in the United States, and only 250 million Internet-enabled PCs. Mobility is crucial when preparing for emergency communications. Integrating voice browser and telephone, VoiceXML offers a means of organizing disparate content into a user-friendly and easily accessible mobile medium. The technology allows a voice command given over any telephone, landline or wireless, to be analyzed by a voice browser that listens, interprets and then speaks through a text to speech engine or pre-recorded audio files. The technology can also be used to push patient reminders such as when to take medications, or when to schedule an appointment, through outbound calling notifications. There is great also an opportunity for application of this service among the 16.7 million visually impaired people in the United States for whom things like reading prescription instructions can be complicated.
For classifying symptoms, diagnoses, treatments and drugs, medicine abounds with indexing systems and controlled vocabularies. The Resource Description Framework (RDF) language from W3C is an XML application that supports the representation of controlled vocabularies, thesauri and term lists where the relations between the terms are weakly defined. Built on top of this is the OWL language to represent ontologies. An ontology is a conceptual model of a domain of discourse, it is not just a thesaurus or a term list. The relations between the item in an ontology are defined much more strictly than in a simple term list or thesaurus. This enables more precise reasoning to weed out erroneously defined terms, and to dynamically generate new concepts and their definitions that can be derived from those already included. In the medical domain thesauri such as UMLS and ontologies such as UK Drug Ontology can be represented in these languages and then interact with the XML representations of other documents.
The advent of XML makes it easier for systems in different environments to exchange information. The universality of XML makes it a very attractive way to communicate information between programs. Programmers can use different operating systems, programming languages, etc., and have their software communicate with each other in an interoperable manner. The same way programmatic interfaces have been available since the early days of the World Wide Web via HTML forms, programs are now accessible by exchanging XML data through an interface, e.g. by using SOAP Version 1.2, the XML-based protocol produced by W3C. The power of Web services, in addition to their great interoperability and extensibility thanks to the use of XML, is that they can then be combined in order to achieve more complex operations. Several programs providing simple services can interact in order to permit complex operations. To this end technologies for the description of web services that may be of use are defined (WSDL) as well as directory services to allow the discovery of services that may be of interest, while technologies are going through the standards process to allow the combination or choreography of simple web services together to provide more complex services. In the medical domain these web srevices provide the secure messaging required to transmit the patient records and test results between medical service providers.