This document discusses designing and managing medical devices that are equipped with software, including a variety of ways of managing the public interest in safety and effectiveness of medical devices that are preferably implemented with open-source software. In one general aspect, a method of updating a medical device is disclosed. The method includes storing a vendor certificate in the device, and receiving and storing a licensed prescriber certificate in the device. A signed request to update code in the medical device can then be received and this request can be authenticated with one of the certificates, and the code can be updated in the medical device with code from the authenticated update request.