Abstract: A portable modular diagnostic medical device. The medical device is based on a portable multipurpose computerized platform, such as those designed primarily for playing video games. A medical component such as a cartridge is removably connected to the platform, and has specialized circuitry specific to a predetermined diagnostic medical function, such as the monitoring of electrocardiograms (ECGs). Different medical functionality is provided for by removably connecting different components into the portable multipurpose computerized platform.