Software safety techniques for implantable medical devices

The embedded microcontroller has become an important part of many implantable medical devices. These systems consist of a microprocessor, RAM, and ROM. The microcontroller inter faces with many other devices including timers, Analog to Digital converters, telemetry circuits, and analog input amplifiers. The design and development of software for these systems has taken on a great deal of importance. As with any system in an implantable device, the software must be safe and, hopefully, improve the reliability of the complete system. In addition to the software reliability, the code must usually be written in a relatively small amount of memory. This paper presents a number of software safety features which have been used in the development of an implantable cardiac pacemaker.