MDR Classification

In this article you can read about this topic, and we are going to clarify all rules based on the MDR. In the first segment you can read about general rules, the second segment we are going to talk about the common definitions and in the last segment you can hear about some examples.

The Medical Device Regulatory ((EU) 2017/745) defines four class for the devices based on their inherent risks. These classes are I, IIa, IIb and III (Article 51). In addition, and according to Article 52 Class I devices can be further subdivided into:

• Is – sterile condition
• Im – measuring function
• Ir – reusable surgical

General rules

There are some implementing rules that shall be adhered by the manufacturers, importers and distributors.

1.  The application of classification rules is determined by the intended purpose of the devices.

2.   If a device is meant to be used alongside another device, classification rules apply separately to each device.

3.   Software that operates a device or impacts its use falls under the same classification as the device.

4.   Devices not specifically designated for a particular body part are classified based on their most critical specified use.

5.   When multiple rules or sub-rules apply to a device based on its intended purpose, the strictest rule leading to the highest classification is applied.

6.   The duration of use of a device is calculated without considering temporary interruptions for procedures, cleaning, or disinfection. The temporary nature of interruptions or removal is determined in relation to usage before and after such events, including devices intended for immediate replacement.

7.    A device enables direct diagnosis if it independently provides disease diagnosis or crucial diagnostic information.

What definitions should be clarified?

For the perfect understanding we should explain some definitions.

Invasive device means any device which, in whole or in part, penetrates inside the body, either through a body orifice or through the surface of the body.

Active device means any device, the operation of which depends on a source of energy other than that generated by the human body for that purpose, or by gravity, and which acts by changing the density of or converting that energy.

The different rules consider the duration of use as 3 definitions.

Transient means normally intended for continuous use for less than 60 minutes.

Short term means normally intended for continuous use for between 60 minutes and 30 days.

Long term means normally intended for continuous use for more than 30 days.

The Annex VIII contains the classification rules that shall be kept in mind for the manufacturers. There are 22 rules, four more than the previous Medical Device Directive (MDD). These rules are the follows:

Classification rules

1-4.: Non-invasive devices

• Rule 1 – Devices that either do not come in direct contact with the patient or contact intact skin only.
• Rule 2 – Channeling or storing for eventual administration.
• Rule 3 – Modify biological or chemical composition of blood, body liquids, other liquids and cells for implantation or administration into the body.
• Rule 4 – Come into contact with injured skin or mucous membrane.

Examples for non-invasive medical devices: stethoscopes, wheelchairs pushed by hand, syringes for infusion pumps, blood bags, IVF cell media without human albumin, wound dressings, ostomy bags, polymer film dressings, etc.

5-8.: Invasive devices

• Rule 5 – Respect to body orifices.
• Rule 6 – Surgically invasive devices intended for transient use.
• Rule 7 – Surgically invasive devices intended for short-term use.
• Rule 8 – Implantable devices and long-term surgically invasive devices.

Examples for invasive medical devices: dental impression materials, stomach tubes, impression trays, urethral stents, powered nasal irrigators, needles used for suturing or syringes, lancets, cardiovascular catheters, neuro-endoscopes, spinal cord retractor, spinal needles, clamps, infusion cannulae, bridges and crowns, CNS electrodes, etc.

9-13.: Active devices

• Rule 9 – Intended to administer or exchange energy.
• Rule 10 – Diagnosis and monitoring or intended for diagnostic or therapeutic radiology.
• Rule 11 – Software intended to provide information to inform decisions with diagnosis or therapeutic use.
• Rule 12 – Administer and/or remove medicinal products, body liquids or other substances to or from the body.
• Rule 13 – All other active devices

Examples for active medical devices: examination lamps, electrocardiographs, gamma cameras, patient monitors, diagnostic X-Ray machine, a mobile app intended to analyze a user’s heartbeat, detect abnormalities, and inform a physician accordingly, anaesthesia machines, pressure regulators for medical gases, electric wheelchairs, etc.

14-22.: Special rules

• Rule 14 – Incorporating, as an integral part, an ancillary medicinal product, and medicinal products derived from human blood or blood plasma.
• Rule 15 – Used for contraception or prevention of sexually transmitted diseases.
• Rule 16 – Specifically disinfecting, cleaning, rinsing, hydrating or sterilizing devices.
• Rule 17 – Record X-ray diagnostic images.
• Rule 18 – Utilizing tissue or cells of human or animal origin or their derivatives.
• Rule 19 – Incorporating or consisting of nanomaterial.
• Rule 20 – Invasive devices, intended to administer medicinal product by inhalation.
• Rule 21 – Composed of substances that are introduced via a body orifice or applied to the skin.
• Rule 22 – Active therapeutic devices, with an incorporated diagnostic function.

Examples for special ruled medical devices: IVF cell media with human albumin, condoms and femidoms, non-hormonal intrauterine contraceptive devices (IUCD or ICD), contact lens storing solutions, x-ray films, animal derived biological heart valves, collagen dermal fillers, spacer intended for metered dose inhalers attached to the inhaler, active coal for oral administration, eye drops for hydration, automated external defibrillators (AED), etc.

Summarize

So, to sum up, understanding and applying these rules is essential for ensuring compliance and proper classification of medical devices in the European market.

As you can see there is lots of rules to be comply with, and much more options when you count on the risk-based classes. If you need help in the classification or any aspect of the MDR please do not hesitate to contact us!