"An individual software application program or group of programs, routines or algorithms that add specific computer assisted display, processing and/or analysis capabilities to a defibrillator intended for external use on the thorax so that it may function according to its intended purpose. A basic set of applications programs and routines are included with the defibrillator and can be upgraded to correct programming errors or to add new system capabilities. Applications program packages are typically identified by a proprietary name and ""version"" or ""upgrade"" number."