iotaMed is intended as an organizing overlay to existing information. It adds the guideline layer, including knowledge transfer and checklist functionality, to the classic electronic health care record. The information needed cannot be stored in the existing EHR systems, simply because they lack the necessary concepts. In other words, we do need our own database to contain the iotaMed information, even though we may leave all the “old” information where it already resides in the legacy EHR. Even the new information added through iotaMed will result in new information to be added to legacy EHR systems, even though that information, by necessity, is as poor as the information currently stored there. There simply is no way to turn this particular toad (the legacy EHR) into a prince.

So, what do we choose for an iotaMed database, that is for the iotaDB? It’s painfully obvious to most that a relational database is very unsuited to this purpose and has always been. Using relational databases for medical information has never been a good idea due to the unstructured or semi-structured nature of medical data. Every EHR I’ve seen that uses relational databases has been a Frankenstein’s monster of inefficiency and inflexibility. It the wrong choice, pure and simple.

Lately, graph databases are becoming popular, and seem to be a much better fit for this purpose. Entities used in medical databases are practically always of variable structure, with a huge number of possible value types, but with only a small number of value types used in each instance. If implemented in a relational database, this results in sparse tables, or more often in blatant misuse of the database where one column is used to define the value type of another column, so that just about anything can be dumped into a single table. It’s horrible.

The “issue”, “issue worksheet”, “clinical guideline”, “item”, and “observation” objects clearly form a graph that would be difficult to squeeze into a relational DB, but would fit nicely into a graph database.

Currently, I’m looking at Neo4j, since it seems to be one of the more evolved open source graph databases.There’s a nice intro to Neo4j here. Neo4j does not seem to have a language binding for Objective-C yet, and it needs Java to run, but since I’m planning on deploying iPads logically tethered to an OSX machine, the Neo4j can run there. The interface between Objective-C and Java would then effectively be a server side proxy app. If somebody already did this, I’d appreciate hearing from you, though.