Experiences in the formalisation and verification of medical protocols

Medical practice protocols or guidelines are statements to assist practitioners and patient decisions about appropriate health care for specific circumstances. In order to reach their potential benefits, protocols must fulfill strong quality requirements. Medical bodies worldwide have made efforts in this direction, mostly using informal methods such as peer review of protocols. We are concerned with a different approach, namely the quality improvement of medical protocols by formal methods. In this paper we report on our experiences in the formalisation and verification of a real-world medical protocol. We have fully formalised a medical protocol in a two-stage formalisation process. Then, we have used a theorem prover to confirm whether the protocol formalisation complies with certain protocol properties. As a result, we have shown that formal verification can be used to analyse, and eventually improve, medical protocols.