Software

Whether software is regulated depends on its intended purpose, not on how it is built. The same code can be a medical device, an accessory or a non-device tool depending on what the manufacturer claims.

For the purpose of this guidance, “software” is defined as a set of instructions that processes input data and creates output data.

MDCG 2019-11 Rev.1, Section 2, Definitions and abbreviations

The set of electronic instructions used to control the actions or output of a medical device, to provide input to or output from a medical device, or to provide the actions of a medical device. This definition includes software that is embedded within or permanently a component of a medical device, software that is an accessory to another medical device, or software that is intended to be used for one or more medical purposes that performs these purposes without being part of a hardware medical device.

FDA guidance: Deciding When to Submit a 510(k) for a Change to an Existing Device (October 2017), Appendix C, Significant Terminology

MDCG 2019-11 uses a broad, technology-neutral definition: a set of instructions that processes input data and creates output data. The FDA 510(k) change guidance ties its definition to medical devices, covering software that controls a device, provides input or output to it, or performs a medical purpose on its own.