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\nFigure 2. Connection between medical records, medical record items, and medical documents
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The main medical record also contains general medical data, such as the list of immunizations, the list of allergies, notes about hospitalizations, etc. Beside the main medical record, some departments (such as dental service, endocrinology, gynecology, pediatrics) within the healthcare system also keep their local medical records related only to their scope. Since there can be several different medical records containing different specific data and many different documents defining data for medical procedures, we defined our data model so that it can be extended easily. In our application modules connection between medical record classes and medical document classes are established as it is shown on the Figure 2. Supporting scheme in the database is exact as a structure of classes. Table MedicalRecordBase is a parent entity for specific medical records and they have established relation one?to?many between parent and each child. Each children entity has an id from MedicalRecordBase as a foreign key. Same hierarchy is established both for MedicalDocumentBase table and tables having it for parent table. In the same time, MedicalRecordBase is parent table for MedicaDocumentBase table which have id from MedicalRecordBase as a foreign key.<\/p>\n
Basically, in our meta model, we have class MedicalRecordHeader (Figure 3) for defining different medical records and MedicalRecordItem to define all different kind of medical documents contained by medical record. Both of them are derived from MedicalDataContainer class. Each MedicalDataConatiner object (MDC in further text) has the list of properties stored as instances of the class MedicalRecordItemElement. For each property, the system stores its name, type and measurement unit. An MDC is also associated with the list of boundaries of normal values (MedicalRecordItemElementRange objects). Such generic modeling (actually, meta-modeling) offers the possibility to perform various extensions (e.g., of the set of medical services) in a uniform and consistent way. It also enables our generator tool (explained briefly in the next section) to automatically create a separate class and a database table for each MDC object. The defined EHR model is usable in any kind of ambulatory medical institution [7], but also in the clinical (hospital) environment because hospitals also keep their own history of illness for each hospitalization.<\/p>\n
Model<\/h2>\n
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\nFigure 3. Main form of data modeling and generating tool
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\nFigure 4. Example of defined medical record item element
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\nFigure 5. Example of defined ranges for medical record item element
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