Legacy Medical Device Software Remediation Example

Architecture reconstruction, verification baseline, and practical remediation planning for legacy device software under IEC 62304 / ISO 14971 context.

Legacy medical device software often remains in active use long after the original architecture has become unclear. Documentation is outdated, software item boundaries are blurred, tests are mostly manual, and changes become risky and expensive.

This example shows what a remediation engagement can look like in practice.

The scenario below is a simplified fiction created for publication. It is not a real customer project. At the same time, the structure, engineering logic, and deliverable style are based on real remediation work on legacy medical device software.

In this example, a portable patient monitor records ECG, SpO2, and pulse data over several days, stores the data locally, and transfers the recordings to a PC application for visualization and export. The sample documents illustrate the kind of inputs, analysis, and outputs a client can expect from a remediation project.

A battery-powered monitoring device records physiological values over several days in a normal daily environment. The device is based on legacy embedded software running on Cortex-M, stores multiple sessions in local flash memory, and transfers the data to a C++/Qt PC application over an isolated USB-to-serial link.

The remediation goal is not a full rewrite. The goal is to reconstruct the current architecture, identify structural and verification weaknesses, and define a controlled remediation path for architecture, refactoring, and testing.

The documents below are shortened publication versions of typical remediation outputs. They are intended to show scope and output style, not to serve as a full implementation package.

More detailed sample deliverables can be provided on request.

Project Input Definition
Defines the system context, intended workflow, hardware/software scope, known constraints, and available project artifacts.

Phase 1 - Current Architecture Reconstruction
Reconstructs the current software architecture, software items, runtime behavior, interfaces, data flow, and likely legacy weak points.

Phase 2 - Remediation Plan
Defines the remediation direction, prioritized refactoring areas, verification improvements, work packages, and practical execution path.

Note: These sample documents are based on a fictionalized example created for publication. They are simplified and sanitized, but the structure and engineering approach reflect real remediation work.