Internal medical device communication bus

In general, the invention facilitates improved inter-module communication within a medical device system, such as an automated external defibrillator (AED), by using a serial data interface based on the USB specification to transfer data between modules. As a result, data transmission rates may be improved significantly, thereby providing ample communication bandwidth for a variety of medical device applications. Further, the serial interconnect nature of the USB interface reduces the number of physical interconnects that are needed to support the interface, thereby reducing the design constraints on the medical device system.