Medical Devices

What Counts as a Medical Device

A medical device is broadly defined as any instrument, apparatus, implant, software, material, or other article intended by the manufacturer to be used for medical purposes, like:

• Diagnosis, prevention, monitoring, treatment or alleviation of disease

• Modifying anatomy or a physiological process

• In vitro diagnostics (e.g., reagents or instruments for testing body samples)

In different jurisdictions, there is a “qualification” or “borderline” assessment to decide whether a product is actually regulated as a medical device. For example, in the UK, they look at: the intended use, mode of action, labelling, and how similar products are regulated.

Why We Grade (Classify) Devices

• To assess risk: Devices that pose more risk to patients/users need more stringent regulation.

• To determine regulatory pathway: What kind of pre-market approval is needed, what documentation, what tests.

• To establish post-market requirements: More risky devices may require more post-market surveillance, reporting, etc.

Common Classification Systems

Here are some of the major classification systems and how grading works in different regions:

USA (FDA)

• The FDA divides medical devices into three classes: Class I, Class II, Class III.

• Risk basis: The classification depends on how risky the device is to patients or users.

• Regulatory controls:

  • General Controls: Required for all classes (e.g., establishment registration, labeling, quality systems).

  • Special Controls: Additional controls for Class II (e.g., performance standards, special labeling).

  • Premarket Approval (PMA): Required for Class III devices (typically high risk) unless exempted.

• Reclassification: The FDA can reclassify devices as new safety data emerges.

European Union / UK (MDR)

• Under EU MDR (Medical Device Regulation 2017/745) and UK regulations, devices are classified more granularly: Class I, Class IIa, Class IIb, and Class III.

• The classification depends on factors like:

  • Intended use

  • Duration of contact with the body

  • Whether the device is invasive or implantable

  • Whether it’s active (e.g., powered)

  • Whether it contains medicinal substances

• Conformity assessment: The higher the class, the more rigorous the conformity assessment (involvement of a Notified Body / Approved Body).

• Classification rules: Annex VIII of MDR defines “rules” (e.g., how to classify based on invasiveness, duration, etc.).

Other Regions (e.g. Australia – TGA)

• The Therapeutic Goods Administration (TGA) in Australia also uses a risk-based classification system.

• Manufacturers must classify their devices correctly because the required regulatory evidence depends on class.

• The intended purpose is critical: the same physical device can be in different classes depending on how it’s used.

Examples of Device Classes

Here are some example devices by class (depending on region):

• Low risk (Class I): Non-electrical bandages, examination gloves, simple surgical instruments.

• Medium risk (Class II / IIa / IIb): Infusion pumps, ventilators, diagnostic imaging devices, some software used for diagnosis.

• High risk (Class III): Pacemakers, implantable defibrillators, joint replacements, devices that sustain or support life.

Key Implications of Classification

1. Regulatory Burden

   • Higher-class devices usually require more documentation, more clinical data, and more rigorous quality systems.

   • For instance, Class III devices under FDA often need a PMA, needing detailed safety & effectiveness data.

2. Cost and Time to Market

   • Higher classes = more testing and validation = higher cost and longer regulatory timelines.

   • But the potential payoff (for high-risk / high-value devices) can justify the investment.

3. Post-Market Obligations

   • More rigorous vigilance, reporting, and possibly post-market clinical follow-up for high-risk devices.

   • Quality management systems (e.g., ISO 13485) are often required, especially for higher-risk devices.

4. Design & Risk Management

   • Risk management (e.g., according to ISO 14971) is closely tied to classification: you need to demonstrate that you’ve identified and mitigated risks appropriately.

   • The classification also influences how you design your device, what materials you use, how you validate it, etc.

Challenges & Nuances

• Borderline Products: Some products are hard to classify (e.g., “is this a medical device or a consumer product?”). Regulators (like the MHRA in the UK) provide guidance.

• Software as a Medical Device (SaMD): Software (even standalone) can be classified depending on what it does (diagnosis, clinical decision support, etc.).

• Reclassification: As technology evolves or new risk data emerges, devices may be reclassified.

• Global Market Differences: Classification rules differ by region, so a device class in the US may not directly correspond to the same class in Europe or Australia.

Why “Grading” Matters for Biotech / Medical-Adjacent Innovations

If you’re working in biotech (or adjacent fields), understanding device classification is critical because:

• If you build a biotech product that is also a device (e.g., a biosensor, diagnostic kit, implantable bioprobe), you’ll need to navigate device regulation.

• Risk drives design decisions: Knowing what class your device is likely to be can influence how you design it (materials, redundancy, safety).

• Regulatory strategy: Device class will affect your go-to-market plan, regulatory budget, clinical trials, quality systems, and post-market strategy.