Green coding in medical technology: Sustainable software development for software medical devices

What is more risky for a software medical device: a visible defect or permanent, unnecessary energy consumption?

Both are problematic. The difference: a defect is noticeable and can be fixed. Permanent energy consumption often goes unnoticed – it runs quietly in the background, around the clock. That is precisely what makes it critical.

Software medical devices (SaMD) and software-driven medical devices are a key driver of innovation in medical technology. They analyse diagnostic data, control devices, support clinical decisions or are integrated as embedded software in in vitro diagnostics, monitoring systems and wearables – often in continuous operation.

This development is leading to an increase in data volumes, algorithms and availability requirements. The result: greater computing load, higher energy consumption and increasing system complexity throughout the entire life cycle.

This is exactly where green coding comes in. Not as a marketing label, but as an engineering response to questions of scaling, stability and maintainability of modern SaMD. Anyone who sees green coding as just a ‘green label’ is missing its true value.

As in football, it is not pure running performance that determines success, but positional play. Efficiency is achieved when unnecessary steps are avoided. That is exactly what this blog post is about. How green coding makes software as a medical device (SaMD) more stable and sustainable, where the greatest leverage lies, and how manufacturers can implement the concept in a standard-compliant and practical manner.

From green IT to green coding

Before we dive deeper, it is worth clarifying the terminology:

• Green IT focuses on IT infrastructure – data centres, hardware, networks, energy supply.
• Green software considers the sustainability of an application over its life cycle – development, operation, decommissioning.
• Green coding focuses on code and architecture decisions that make efficient use of energy, memory and computing power.

Green coding is the decisive lever for SaMD. Infrastructure can be retrofitted or replaced. Architecture and code errors, on the other hand, scale with and accompany a product across versions, releases and often throughout its entire life cycle.

What green coding means for SaMD

Two software medical devices, same purpose, same approval, yet one runs stably for years while the other struggles with latency, failures or continuous load. The cause rarely lies in the medicine, but in the code and architecture design, because both teams know the rules, but only one is in the right place. SaMDs are no longer an ‘add-on’; they must function reliably under real operating conditions, not just in the validation laboratory.

Green coding does not mean ‘less performance’ here, but rather less unnecessary movement. Specifically, this means:

• Avoiding unnecessary calculation cycles
• Clear, lean data and control flows
• Event-based rather than continuous processing
• Clean separation of core medical and supporting logic

This results in software that runs more stably, predictably and scalably in everyday use.

Why green coding is necessary

Many SaMDs work perfectly at the time of approval, but the real problems arise later in the field, under real load and in continuous operation.

When systems are constantly pulling, pushing data through the pipeline multiple times and logging unfiltered or continuously, continuous load is inevitable and behaviour becomes difficult to predict.

The consequences:

• Thermal stress and component ageing
• Unstable runtime behaviour
• Growing complexity in scaling and updates, particularly critical for SaMD on unchangeable hardware

This is where consistent green coding comes in: more efficient architecture, lean design and clean implementation ensure more stable runtimes, better response times, controllable scaling and lower operating and infrastructure costs.

Is this in line with regulations? Yes!

• IEC 62304 allows refactoring and optimisation as long as the intended purpose, function and safety class remain unchanged.
• ISO 14971 requires a risk-based assessment of changes, not their avoidance.
• Medical Device Regulation (MDR) requires safety, performance, transparency and traceability, not ‘maximum computing load’.

Green coding is therefore not a freestyle exercise, but training theory for SaMD – in football terms: not chasing after the ball, but controlling the game from a stable back four.

Score points with green coding? Yes. Replace safety? No.

Green coding for SaMD:

• Does not replace safety requirements
• Does not circumvent regulatory requirements
• Does not fix poor architecture

Optimisations can trigger re-verification, energy efficiency must fit into existing quality targets and without clear metrics, efficiency gains remain an assertion.

As in football, without clear technique, roles and a playing system, even the best positional play remains unstable.

A playing field for green coding in SaMD

To prevent green coding from becoming a risk itself, structure is needed. A practical framework is the ‘green software’ model with life cycle thinking, in which software is considered throughout its entire life cycle, from development to decommissioning.

On this basis, five phases can be defined:

• Architecture & design

  • Separation of safety and non-safety components
  • Event-based processing instead of continuous polling
  • Reduced, traceable data and control flows
• Risk & impact analysis

  • Identify affected components
  • Check safety relevance
  • Derive verification/validation requirements
• Controlled implementation

  • Focus on UI logic, logging/monitoring, data pre-processing, communication/integration
  • Medical core remains stable
• Verification & validation

  • Load and runtime tests
  • Resource and, if necessary, energy profiles
  • Regression tests of safety-critical paths
• Operation & monitoring

  • Continuous monitoring of system load and runtime
  • Targeted refactoring in maintenance and change management
  • Documentation of relevant effects

In football terms, this means that it is not about a new playing system, but about a better understanding of the game.

Tools for green coding

Green coding is not a topic for the future. The tools have long been available, from models such as Software Carbon Intensity (SCI) and architecture patterns from the Green Software Foundation to scalable cloud platforms and embedded profiling tools to EU initiatives and eco-labels such as the Blue Angel.

Tools cannot replace risk management, but without them, efficiency remains merely a claim and does not become a verifiable characteristic.

Conclusion: Efficiency determines the future of SaMD

Green coding addresses a structural problem: more data, more runtime, more complexity – with the same hardware and the same regulatory requirements. Efficiency becomes a question of future viability: technically, regulatorily and economically.

This is where adesso comes in. We combine medical technology know-how with software expertise and support SaMD manufacturers in implementing green coding in a practical and standards-compliant manner:

• Regulatory compliance – experience with MDR (Medical Device Regulation), IEC 62304 (software life cycle), IEC 62366-1 (usability), ISO 14971 (risk management), ISO 13485 (quality management system)
• Empowering teams – training courses, workshops, support in day-to-day project work
• Strategic thinking about sustainability – green coding as a building block of a sustainable product and IT strategy

This is how adesso becomes a co-trainer: the rules are set – we ensure that SaMD is not only approved, but also remains efficient, stable and economically competitive in the long term.