Section 3
Device Classification Under MDR and IVDR
Understanding the risk-based classification systems for medical devices and in vitro diagnostic devices in the European Union.
The Principle of Risk-Based Classification
Classification is the cornerstone of medical device regulation in the European Union. The level of regulatory scrutiny a device receives—including the conformity assessment procedures, clinical evidence requirements, and post-market surveillance obligations—is directly determined by its classification.
Both the MDR and IVDR employ risk-based classification systems where devices presenting higher risks to patients or users are subject to more stringent regulatory requirements. Understanding how to correctly classify devices is essential for healthcare workers involved in procurement, clinical evaluation, and device management.
Incorrect classification can have serious consequences: under-classification may result in inadequate safety controls reaching patients, while over-classification leads to unnecessary regulatory burden and potential market access delays.
MDR Classification Classes
The Medical Device Regulation classifies devices into four classes based on their intended purpose and inherent risks. This system is fundamentally unchanged from the MDD, but the rules for determining classification have been expanded and refined.
Devices with the lowest risk profile. Generally non-invasive devices or those with minimal contact with the body.
Examples: Wheelchairs, hospital beds, stethoscopes, bandages, tongue depressors, reusable surgical instruments (non-sterile)
Devices with moderate risk, often involving short-term invasive contact or energy delivery to the body.
Examples: Hearing aids, diagnostic ultrasound, urinary catheters (short-term), dental crowns, contact lenses
Devices with higher risk, typically long-term invasive devices or those that administer/remove substances from the body.
Examples: Ventilators, infusion pumps, bone fixation plates, haemodialysis equipment, surgical lasers
Highest risk devices, typically implantable, life-supporting, or those incorporating medicinal substances or tissues.
Examples: Cardiac pacemakers, hip implants, coronary stents, breast implants, implantable defibrillators
Class I Sub-Categories
While Class I devices generally require self-declaration of conformity, certain sub-categories require Notified Body involvement:
Class Is
Devices placed on market in sterile condition. NB assesses sterilisation aspects.
Class Im
Devices with measuring function. NB assesses metrological aspects.
Class Ir
Reusable surgical instruments. NB assesses reprocessing aspects.
MDR Classification Rules (Annex VIII)
The MDR contains 22 classification rules organised into four chapters based on the nature of the device. When multiple rules apply, the highest resulting classification is used. Understanding these rules helps healthcare workers verify that devices are appropriately classified for their intended use.
Chapter I: Non-Invasive Devices (Rules 1-4)
Rule 1 (Default)
All non-invasive devices are Class I unless other rules apply.
Examples: Examination gloves, collection containers, wheelchairs
Rule 2 (Channelling/Storage)
Devices intended for channelling or storing blood, body fluids, cells, or tissues for transfusion, infusion, or transplantation.
Class IIa generally; Class IIb if connected to Class IIa/higher active device; Class III if blood bags
Rule 3 (Biological Modification)
Devices that modify the biological or chemical composition of human tissues, cells, blood, other body fluids, or liquids for infusion.
Class IIb generally; Class III if treatment involves filtration, centrifugation, or exchange of gas/heat
Rule 4 (Wound Contact)
Non-invasive devices in contact with injured skin.
Class I for mechanical barrier/compression/absorption; Class IIa for wounds breaching dermis; Class IIb for chronic or extensive wounds
Chapter II: Invasive Devices (Rules 5-8)
Rule 5 (Body Orifice - Non-Surgical)
Invasive devices via body orifices (not surgically invasive), not connected to active devices.
Class I if transient use; Class IIa if short-term use; Class IIb if long-term use (except oral to pharynx, ear canal, nasal cavity)
Rule 6 (Surgically Invasive - Transient)
Surgically invasive devices intended for transient use (<60 minutes).
Class IIa generally; Class IIb if controlling/diagnosing vital functions or in direct contact with CNS/heart; Class III for some specific uses
Rule 7 (Surgically Invasive - Short-Term)
Surgically invasive devices intended for short-term use (60 min to 30 days).
Class IIa generally; Class IIb if monitoring/controlling vital functions or in contact with CNS; Class III if direct contact with heart or central circulatory system
Rule 8 (Implantable & Long-Term Surgically Invasive)
Implantable devices and long-term surgically invasive devices (>30 days).
Class IIb generally; Class III if in contact with heart/CNS/central circulatory, or active implantables, or has biological effect, or undergoes chemical change, or administers medicines
Chapter III: Active Devices (Rules 9-13)
Rule 9 (Therapeutic Active Devices)
Active therapeutic devices intended to exchange or administer energy.
Class IIa generally; Class IIb if energy/substances administered in potentially hazardous way; Class III if intended to control/monitor active implantable device performance
Rule 10 (Diagnostic Active Devices)
Active devices intended for diagnosis or monitoring.
Class IIa generally; Class IIb if for direct diagnosis/monitoring of vital functions; Class I if for external monitoring of non-vital parameters
Rule 11 (Software) - NEW UNDER MDR
Software intended to provide information for diagnostic or therapeutic decisions.
Class IIa minimum; Class IIb if decisions could cause serious deterioration; Class III if decisions could cause death or irreversible deterioration
Rule 12 (Administering Substances)
Active devices intended to administer/remove medicinal products, body fluids, or other substances.
Class IIa generally; Class IIb if potentially hazardous manner
Rule 13 (Other Active Devices)
All other active devices not covered by Rules 9-12.
Class I
Chapter IV: Special Rules (Rules 14-22)
Rule 14 (Incorporating Medicinal Substance)
Devices incorporating a medicinal substance as integral part with ancillary action.
Class III
Rule 15 (Contraception/STI Prevention)
Devices for contraception or prevention of sexually transmitted infections.
Class IIb generally; Class III if implantable or long-term invasive
Rule 16 (Disinfection/Sterilisation)
Devices specifically intended for disinfecting, cleaning, rinsing, or hydrating contact lenses.
Class IIb for disinfecting/sterilising medical devices; Class IIa for contact lens solutions
Rule 17 (Recording Diagnostic Images)
Devices for recording X-ray diagnostic images.
Class IIa
Rule 18 (Tissues/Cells/Derivatives)
Devices utilising non-viable tissues or cells of human or animal origin, or derivatives.
Class III for human origin; Class III for animal origin contacting injured skin/mucous membrane
Rule 19 (Nanomaterials) - NEW UNDER MDR
Devices incorporating or consisting of nanomaterials.
Class III if high/medium internal exposure potential; Class IIb if low internal exposure; Class IIa if negligible exposure
Rule 20 (Invasive via Body Orifice - Surgical)
Invasive devices via body orifices that are surgically invasive and intended for connection to active device.
Class IIa minimum; higher if connected to Class IIa or higher active device
Rule 21 (Substances via Body Orifices)
Devices composed of substances intended to be introduced into body via orifice or dermal application and absorbed/dispersed.
Class III if absorbed systemically; Class IIb if locally dispersed; Class IIa if applied to nasal/oral mucosa
Rule 22 (Active Therapeutic with Integrated Diagnostic)
Active therapeutic devices with integrated or incorporated diagnostic function significantly determining patient management.
Class III (closed loop systems, automated external defibrillators)
Duration Definitions Under MDR
The duration of device contact with the body is a critical factor in classification. The MDR defines three duration categories:
| Duration Category | Definition | Examples |
|---|---|---|
| Transient | Normally intended for continuous use for less than 60 minutes | Examination gloves, tongue depressors, injection needles |
| Short-term | Normally intended for continuous use for between 60 minutes and 30 days | Short-term urinary catheters, nasogastric tubes, wound drains |
| Long-term | Normally intended for continuous use for more than 30 days | Long-term catheters, orthopaedic implants, pacemaker leads |
Important: "Continuous use" means uninterrupted actual use for the intended purpose. If a device is intended for intermittent use, the accumulated duration of use determines the category. Replacement of the same device with an identical new one without interruption is considered continuous use.
IVDR Classification System
The In Vitro Diagnostic Regulation (EU) 2017/746 introduces a completely new classification system for IVDs, replacing the list-based approach of the IVDD with a risk-based system similar to the MDR. This represents one of the most significant changes for laboratories and healthcare facilities using diagnostic devices.
IVDs presenting low risk to the individual and low public health risk.
Examples: Clinical chemistry analysers (general), specimen receptacles, laboratory glassware, culture media (general purpose)
IVDs presenting moderate individual risk or low public health risk.
Examples: Pregnancy tests (self-testing), urine test strips, vitamin D tests, cholesterol tests, HbA1c tests (non-diabetes management)
IVDs presenting high risk to the individual or moderate public health risk.
Examples: Blood glucose meters (diabetes management), HLA typing, PSA tests, tumour markers, companion diagnostics
IVDs presenting high public health risk or with results that are life-threatening.
Examples: Blood grouping (ABO, Rh), HIV tests, Hepatitis B/C tests, blood screening for transfusion safety
IVDR Classification Rules (Annex VIII)
The IVDR contains 7 classification rules. Unlike the MDR, IVDR classification is primarily determined by the intended purpose of the test and its impact on patient management or public health.
Devices intended for blood grouping or tissue typing to ensure compatibility of blood, blood components, cells, or tissues for transfusion or transplantation are Class D, except for devices intended for ABO confirmation testing which are Class C.
Devices intended for detection, confirmation, or quantification of markers of transmissible agents in blood, blood components, cells, tissues, or organs intended for transfusion or transplantation are Class D. Devices for screening/confirmation of infectious diseases are Class C (or Class D if high public health risk).
Devices intended for detection of life-threatening, highly infectious agents, congenital disorders in foetuses/newborns where early detection is essential, or determining infectious disease stage are Class C. Cancer screening and companion diagnostics are also Class C.
Devices intended for self-testing are classified as: Class C if for detecting serious diseases or conditions; otherwise Class B. Near-patient testing by health professionals follows regular rules.
Devices for general laboratory use, specimen receptacles, devices specifically intended for in vitro diagnostic procedures which do not have critical characteristics are Class A.
Instruments specifically intended for use with IVDs are classified in their own right: Class A for general laboratory instruments; Class B if their characteristics are critical for the result.
All other IVDs not covered by Rules 1-6 are Class B.
Impact of IVDR Classification Changes
The transition from the IVDD to the IVDR represents a dramatic shift in how IVDs are regulated. Under the IVDD, approximately 80% of IVDs could be self-certified by manufacturers. Under the IVDR, approximately 80% of IVDs will require Notified Body involvement.
| Aspect | IVDD (Old) | IVDR (New) |
|---|---|---|
| Classification System | List-based (Annex II List A, List B, Self-Test, General) | Risk-based (Class A, B, C, D) |
| NB Involvement | ~20% of IVDs | ~80% of IVDs |
| Self-Certification | ~80% of IVDs (general purpose) | Only Class A (with conditions) |
| Companion Diagnostics | Not specifically addressed | Class C with specific requirements |
| Laboratory Developed Tests | Generally exempt | Included with limited exemption (Article 5(5)) |
Impact on Healthcare Laboratories
Healthcare laboratories face significant impacts from IVDR classification changes. Tests that were previously self-certified by manufacturers now require Notified Body certification, potentially affecting availability and cost. Laboratory Developed Tests (LDTs) must now meet specific requirements under Article 5(5) or obtain full certification.
Software Classification: A Detailed Analysis
Software classification under MDR Rule 11 represents one of the most significant changes from the MDD. Healthcare facilities increasingly rely on clinical decision support systems, diagnostic algorithms, and health applications that now fall under medical device regulation.
MDR Rule 11 Decision Tree
Step 1: Is it software with a medical purpose?
Software must have an intended medical purpose (diagnosis, prevention, monitoring, prediction, prognosis, treatment, or alleviation of disease) to be a medical device.
Step 2: Does it provide information for clinical decisions?
Software intended to provide information used for taking decisions with diagnosis or therapeutic purposes is subject to Rule 11.
Step 3: What are the consequences of those decisions?
Software Classification Examples
| Software Type | Classification | Rationale |
|---|---|---|
| AI for detecting melanoma from dermoscopy images | Class III | Missed diagnosis could lead to death |
| Sepsis early warning algorithm | Class III | Late sepsis detection can be fatal |
| Insulin dosing calculator | Class IIb | Incorrect dosing could cause serious harm |
| Drug interaction checker | Class IIb | Missed interactions could cause serious harm |
| Appointment scheduling system | Not MD | Administrative function, no medical purpose |
| Patient monitoring data display | Class IIa | Displays information but clinician makes decision |
| ECG analysis with arrhythmia detection | Class IIb | Vital function monitoring with diagnostic output |
MDCG 2019-11 Guidance
The Medical Device Coordination Group has published guidance document MDCG 2019-11 on the qualification and classification of software. Key principles include: software that only stores, archives, communicates, or searches data without modifying it is generally not a medical device; software that applies algorithms to transform data into clinically meaningful information may be a medical device depending on its intended purpose.
Case Study: Reclassification of Hospital Infusion Pumps
Situation: A regional hospital in the Netherlands was reviewing its infusion pump inventory as part of MDR transition planning. The hospital used three types of infusion pumps from different manufacturers.
Classification Analysis:
- Volumetric Infusion Pump: Active device administering substances in potentially hazardous manner → Rule 12 → Class IIb (unchanged from MDD)
- Syringe Pump with drug library: Active device with integrated software providing dosing guidance → Rule 11 interaction with Rule 12 → Class IIb, but software functionality must be separately assessed
- Patient-Controlled Analgesia (PCA) Pump: Active device administering controlled substances with patient-triggered delivery → Rule 12 → Class IIb, with additional Rule 22 consideration for closed-loop functionality
Key Finding: While the hardware classification remained largely unchanged, the software components required separate assessment under Rule 11. The drug library software in the syringe pump was classified as Class IIb due to its role in therapeutic decision-making.
Action: The hospital updated its device register to separately track the software versions and ensured procurement specifications required manufacturers to provide Rule 11 classification evidence for embedded software.
Case Study: Community Laboratory IVDR Transition
Situation: A community diagnostic laboratory in Ireland serving multiple GP practices faced significant challenges transitioning its test menu to IVDR compliance. The laboratory performed approximately 200 different tests using both commercial IVDs and laboratory developed tests.
IVDR Classification Impact:
- HbA1c testing (diabetes management): Moved from general IVD (self-certified) to Class C → Required Notified Body certification
- PSA testing: Moved from general IVD to Class C (cancer screening) → Required Notified Body certification
- Hepatitis B/C screening: Moved from List A to Class D → Enhanced Notified Body scrutiny required
- Therapeutic drug monitoring: Various classifications from Class B to Class C depending on the drug
Challenges Encountered:
- Several test manufacturers discontinued European distribution due to certification costs
- Alternative reagents from certified manufacturers had different performance characteristics
- Laboratory developed tests for rare conditions required Article 5(5) compliance documentation
- Clinical validation studies needed to demonstrate equivalence of replacement assays
Resolution: The laboratory worked with a clinical chemist to validate alternative assays, consolidated some testing to reference laboratories with certified methods, and documented Article 5(5) compliance for essential LDTs serving specific patient populations.
Case Study: AI Diagnostic Software Procurement
Situation: A university hospital in Germany was evaluating an AI-powered chest X-ray analysis system for deployment in its emergency department. The software was designed to flag potential pneumothorax, pneumonia, and other acute findings for radiologist review.
Classification Assessment:
- The software provides diagnostic information used by clinicians for treatment decisions
- Missed pneumothorax could lead to serious deterioration (respiratory failure)
- Rule 11 applies: Class IIb at minimum, potentially Class III for certain indications
Procurement Due Diligence:
- Verified MDR CE marking with correct classification (Class IIb confirmed)
- Reviewed Notified Body certificate validity
- Assessed clinical evidence supporting claimed performance
- Evaluated post-market surveillance plan and update mechanism
- Confirmed manufacturer's cybersecurity measures and software update procedures
Key Lesson: AI/ML medical devices require careful classification assessment and ongoing monitoring. The hospital established a process for verifying continued compliance as software updates are deployed.
Verifying Device Classification
Healthcare workers involved in procurement and device management should verify that devices are appropriately classified. Incorrect classification may indicate inadequate regulatory compliance.
Verification Checklist
- 1Review the EU Declaration of Conformity—it must state the device classification and applicable classification rules.
- 2Check EUDAMED for device registration information including stated classification.
- 3Verify Notified Body certificate (for Class IIa and above) matches the device and manufacturer.
- 4Compare the intended purpose in the IFU against the classification claimed—does the classification seem appropriate for the risks involved?
- 5For software devices, verify Rule 11 has been considered and appropriately applied.
- 6For devices with multiple intended purposes, verify the highest applicable classification has been applied.
Key Takeaways for Healthcare Workers
Classification determines the level of regulatory scrutiny—higher class means more clinical evidence and Notified Body oversight.
Software classification under MDR Rule 11 typically results in Class IIa minimum—most clinical software is now regulated.
IVDR dramatically changes IVD classification—approximately 80% of IVDs now require Notified Body involvement.
Duration of device contact (transient, short-term, long-term) significantly affects classification for invasive devices.
Verify classification claims during procurement—incorrect classification may indicate compliance issues.
New MDR rules (nanomaterials, Rule 19; active therapeutic with diagnostics, Rule 22) may affect devices in your facility.