Software in a Medical Device (SiMD) refers to software that is embedded within, or required for, the operation of a hardware medical device - such as firmware controlling an infusion pump or imaging system. SiMD is regulated as part of the hardware device it runs in, so it goes through the same submission and is subject to IEC 62304, cybersecurity requirements and design controls along with the device. Firmware updates can still trigger regulatory assessments, such as whether a new 510(k) is needed. The distinction from SaMD matters for classification, labeling and how software-only updates are handled.

Why it matters

Unlike SaMD, SiMD is regulated as part of the parent device. It is still subject to IEC 62304, cybersecurity requirements, and design controls.

Common pitfalls

•Failing to integrate SiMD development and maintenance into the overall medical device's lifecycle management processes can lead to regulatory non-compliance.
•Overlooking the specific cybersecurity risks associated with integrated software can compromise the safety and effectiveness of the medical device.
•Treating SiMD with less rigor than standalone software regarding design controls and validation activities is a common mistake.
•Assuming that general software development practices are sufficient without adapting them to medical device regulations is a pitfall.
•Neglecting to update SiMD in response to new cybersecurity threats or operating system changes can lead to vulnerabilities and regulatory issues.

Sources

FDA Software Functions · FDA
FDA - AI/ML-Enabled Medical Devices · FDA
IMDRF - Software as a Medical Device · IMDRF

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Common comparison patterns

Regulatory pathway choice - 510(k) vs PMA, 510(k) vs De Novo, Abbreviated vs Special 510(k).
Quality systems - QSR vs ISO 13485, QMSR vs QSR.
Software classification - SaMD vs SiMD, Locked vs adaptive AI.
EU frameworks - MDR vs IVDR, CE Mark vs UKCA.
Cybersecurity artifacts - SPDX vs CycloneDX SBOM, CVE vs CVSS.
Post-market actions - Recall vs field action, Removal vs correction.

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MedTech Terms is a vendor-neutral community resource sponsored by Blue Goat Cyber. Definitions are written for educational use and are not legal or regulatory advice.