A threat analysis of a medical device for critical patient monitoring -
Licensed under the Creative Commons Attribution License

Danny Lieberman

A threat analysis was performed on a network of Windows-based embedded medical devices used for patient monitoring.  The system helps hospital staff prevent crisis situations through ongoing supervision of patient status, early detection of warning signs, and alert notifications of changes in patient condition.  The threat analysis used the PTA (Practical threat analysis) methodology, described in Appendix A of the medical device threat analysis report. 

Our analysis considered threats to three assets: the ability of the medical device to monitor patients, the hospital enterprise network and patient confidentiality/HIPAA compliance Following the threat analysis, a prioritized plan of security countermeasures is suggested in Section III. We devoted special interest to the issue of propagation of viruses and malware into the hospital network. 

Our analysis clearly shows that there is no added value in installing anti-virus software on the medical devices. Agent software such as an anti-virus does not reduce residual risk and only serves to increase complexity of the medical device configuration; a detailed discussion appears in Section IV of our paper. Section V proposes a way of segregating bio-med functions from the hospital enterprise IT.  Section VI provides a summary of the analysis and its findings. 

A novel benefit of our approach is derived by providing the analytical results as a standard PTA threat model database, which can be used by medical device manufacturers and hospital customers to model changes in risk profile as technology and customer environment evolve. 

Download the detailed threat analysis and discussion of HIPAA compliance of medical devices and download the medical device threat model.