The link below gives a brief idea into the scenes of hacking implantable medical devices. As the blog states it has been termed - "Medjacking". The link has an overall picture and summary of several research papers that have found success in the realm of breaking into medical devices. My blog will delve further into details of the same and providing more detailed overall picture with additional technical details.

http://resources.infosecinstitute.com/hcking-implantable-medical-devices/