XML as a Database

An XML database is the data persistence software system which enables data to be exported, imported and accessed in an XML format. There are two types of XML databases such as native XML and XML-enabled. The XML-enabled maps all XML to the traditional database (like the   relational database), rendering XML as output and accepting the XML as input . The native XML database type has the internal model which depends on the XML and utilizes XML documents as the basic unit of storage.

The native open-source XML database, eXist 1.1.1, to manage and store the EHR and medical images. The Java servlet inserts the record into the eXist database. It indexes collections  and stores of XML documents in both mapped and native  forms for extremely effective querying, retrieval and transformation. The EHRs are stored in eXist database according to the ANSI/HL7 CDA Release One template. CDA distinguishes three different levels of granularity, where each level iteratively adds more markups to clinical documents although the clinical content remains constant at all levels.

The scope of the CDA is the standardization of clinical documents for exchange. A HL7/CDA structure may include texts, sounds, pictures and all kind of multimedia contents. It can refer to external documents, procedures, observations and acts. It includes information about authors, authenticators, custodians, participants, patients and so on.

The XML-based architecture described in the CDA Release One standard has been used to define the health information format. Thanks to the use of XML-based technologies and HL7 specifications, our application fulfils the EHR standards. Its development methodology is a continuously evolving process that seeks to carry out specifications that facilitate interoperability between healthcare systems. EHR with fundus photographs arc stored in eXist database according to the HL7/CDA Release One template. CDA Header in an EHR in TeleOftalWeb is showed. The CDA Header identifies and classifies the document and provides information on the document authenticator the patient, the encounter, the provider and other service actors. Document-related information includes the id, set id, version, type and var­ious timestamps. The id element uniquely identifies the specific clinical document. The type and version elements identify the clinical document template.

Questionnaire:

• What is XML database? Explain.