Classification of medical equipment according to risk

In the healthcare sector, patient safety comes first. For this reason, medical equipment must comply with certain regulations to ensure its reliability, efficiency and traceability. The classification of medical equipment regulatory requirements can be tailored according to the level of risk represented by each medical equipment for patients.

Depending on the type of riska series of controls and evaluations that must be carried out before they reach the market and can be marketed.. The higher the risk, the more rigorous and demanding the processes of clinical evaluation, quality control, technical documentation and post-marketing follow-up become. In the following article, we discuss how medical products are classified. in accordance with MDR (Medical Device Regulation).

Entry into force of the MDR standard for the classification of medical equipment

The MDR (Medical Device Regulation) regulation, officially known as the Regulation (EU) 2017/745 on medical devicesis the legal framework in force in the European Union for the regulation of medical devices. It is a European regulation that replaces the former Directive 93/42/EEC (MDD) and Directive 90/385/EEC on active implantable devices. In contrast to the directives, the MDR has a direct effect in all EU Member Stateswithout the need to adapt national laws.

It was approved on April 5, 2017 with the aim of reinforcing the safety, traceability and efficacy of these products on the European market, but its official entry into force did not arrive until May 25, 2017. As of May 26, 2021 and after a transition period of 4 years, its application became mandatory throughout the European Union.. For certain products certified under the old MDD standard, there is an extended transition period until 2027-2028.

Main changes in MDR regulations

The MDR replaced Directive 93/42/EEC (MDD). with a more precise and strict regulation. This regulation established new more detailed rules for classifying devices according to risk level. To this end, a number of specific criteria were applied, such as duration of use, invasiveness, area of the body affected and type of operation (active or passive). At the same time, it also added specific rules for medical software and the AI softwarewhich were not sufficiently covered before.

The main changes introduced were as follows:

• More specific and strict classification rules, strengthening clinical and technical evaluation.
• Increased control and new classification of implantable products and medical software
• More rigorous assessment by notified bodies
• Enhanced post-marketing surveillance requirements
• Introduction of EUDAMED system for increased traceability and transparency
• Direct and uniform application in all EU countries
• Adapting the regulatory framework to new technologies, such as medical software and artificial intelligence applied to medicine

Classification of medical equipment according to MDR

The MDR regulation establishes a classification system in four different classes (I, IIa, IIb and III) according to the potential risk that the medical equipment represents for the user.

Class	Risk	Features	Examples
Class I	Under	Non-invasive External or superficial use No critical function	Bandages Gloves Simple thermometers
Class IIa	Moderate	Short-term invasive They may have software Limited interaction with internal organs	Headphones Short catheters Basic medical software
Class IIb	High	Invasive of medium/long duration Act on vital functions Prolonged use in internal organs	Respirators Infusion pumps Neonatal incubators
Class III	Very high	Long-term implantable Affect vital functions Use in circulatory or nervous system	Pacemaker Stents Therapeutic AI software

 

Class I - Low risk

Class 1 medical devices are non-invasive equipment, for temporary or external usewhich do not interact directly with physiological functions critical body parts. Their design and use involves a minimal risk for the patient.

Main features

• They do not require electricity or software to operate, they are "passive".
• Used on the surface of the body or in a superficial manner
• They may include variants such as:
  • Is (sterile)
  • Im (measuring function)
  • Go to (surgical reusables)

Examples

• Gauze, bandages and sticks
• Mercury-free thermometers
• Non-sterile medical gloves
• Manual wheelchairs

Type of evaluation

Generally, it is requires manufacturer's self-certificationexcept for the variants Is, Im and Ir, which require assessment by a notified body.

Class II - Moderate and high risk

Class 2 medical devices include two different modalities: Class IIa devices, which have a moderate risk, and Class IIb devices, which have a high risk.

Class IIa - Moderate risk

Includes short-term invasive medical deviceswhich are in use for less than 30 days, or active, which may have a moderate impact on health of the patient. This type of medical products can enter body cavities o use in non-critical diagnostic or therapeutic procedures.

Main features

• Invasive through natural orifices or with limited medical intervention
• Can be electrically powered or contain software
• The risk is higher than in Class I, but still limited.

Examples

• Hypodermic needles
• Short-term catheters
• Headphones
• Non-critical monitoring software

Type of evaluation

Requires the participation of a notified body which evaluates technical documentation and clinical evidence, although it is less complex than in the higher classes.

Class IIb - High risk

It includes devices that can have a significant impact on vital physiological functions, which are long-term invasive or acting on critical internal organs. Also included is the software that directly influences relevant clinical decisions.

Main features

• Invasives of medium or long duration
• They act on the circulatory system or the central nervous system (if not for prolonged use)
• Includes devices that deliver automatic treatments

Examples

• Respirators
• Neonatal incubators
• Hemodialysis equipment
• Diagnostic imaging software with AI
• Programmable infusion pumps

Type of evaluation

Requires comprehensive clinical evaluation, technical review by a notified body and strict compliance with regulatory requirements.

Class III - Very high risk

Class 3 devices present the highest level of risk, since they may have a direct impact on vital functions or its use may involve critical intervention in the human body. Includes permanent implantable devices and stand-alone software for diagnosis or therapy.

Main features

• Long-term or permanent implants
• Long-term invasive devices in the central nervous system or circulatory system
• Software with autonomous therapeutic functions

Examples

• Pacemaker
• Intracoronary stents
• Cardiac valve prostheses
• Brain implants
• Artificial intelligence software provides oncology treatment solutions

Type of evaluation

Requires a mandatory full clinical evaluationincluding studies with patients. To this end, the notified body is involved at each stageThe following steps are required: development, manufacturing, documentation, post-sales surveillance. This type of medical equipment, being so high-risk, requires intensive post-marketing follow-up.

Factors that determine the classification of medical devices according to the MDR

The MDR regulation (Regulation (EU) 2017/745) establishes specific criteria for classifying medical devices according to their level of risk to the patient and the healthcare professional. What are the factors that determine the classification according to their risk?

Duration of use

This refers to the length of time the device remains in contact with the body. The longer the duration of contact, the greater the potential risk.

• Temporary useLess than 60 minutes
• Short-term useBetween 60 minutes and 30 days
• Long-term use: More than 30 days

Degree of invasiveness

Evaluates whether and how the device penetrates the body. Implantable or surgical devices are rated higher.

• Non-invasiveDoes not penetrate the body (e.g. bandages, external thermometers).
• Invasive through natural orificesIt enters through the mouth, nose, ear, urethra, etc.
• Surgical invasiveRequires medical intervention for insertion
• ImplantableRemains inside the body for a prolonged period of time.

Affected body part

The MDR standard checks the site where the device acts in order to assess its risk. This risk increases when it affects a critical area of the human body.

• Body surface or skin: lower risk
• Internal organs or sterile cavitiesintermediate risk
• Central nervous system or circulatory system: high risk

Active or passive use

Active devices can fail and their impact on the organism is greater, so they tend to be classified in higher classes.

• Passive deviceOperates without energy source (e.g., syringes, dressings).
• Active deviceRequires electrical or mechanical power to operate (e.g., respirators, infusion pumps).

Medical purpose

Another aspect that should be analyzed is the function performed by the device in the medical treatment or diagnosis. The higher the functional complexity and clinical relevance, the higher the risk in the classification. In this context, the following medical purposes can be differentiated:

• Basic monitoring
• Diagnose, treat or monitor medical conditions
• Supports physiological functions
• It is used for prevent diseases
• Directly influences clinical decisions

Use of software

The MDR establishes clear rules for classifying medical software according to its use and clinical applications. The risk does not depend on the hardware, but on the purpose and clinical impact of the software.

• Data management softwareClass I: Included in Class I
• Software that aids in diagnostics or clinical decisionsClass IIa or IIb: Incorporated in Class IIa or IIb.
• Autonomous software that makes therapeutic decisionsClass III: They are included in Class III because of increased risk.

Nature of the content covered

It is important to analyze whether the devices come into contact with the human body or alter the chemical composition of the organism. What options can we find depending on the nature of the content?

• The device enters contact with blood, body fluids, or tissues
• Modifies substances (chemically or thermally)
• Administers medication or energy

The MDR regulation comprehensively analyzes how, where, how long and for what purpose a medical device is used. Each of these factors contributes to assigning it a risk class (I, IIa, IIb or III), which determines the legal and clinical requirements necessary to market it.

Importance of proper hazard classification of medical equipment

Classifying medical devices according to their risk is essential to ensure the safety of patients and users, and also to ensure that products comply with the appropriate regulatory requirements before they are marketed or used. What is the role of proper classification in the healthcare sector?

Protection of patients' health and lives

The classification makes it possible to identify the potential hazard level of a device. In this way, the necessary controls can be put in place to prevent failures that could cause harm to patients or healthcare professionals.

Determines the level of regulation and control

Higher-risk devices (Class III) require more rigorous clinical evaluations, testing, certification and post-market surveillance. In contrast, low-risk (Class I) devices follow simpler procedures, such as self-declaration of conformity by the manufacturer. This ensures that each device goes through a process commensurate with its level of risk.

Guidance to manufacturers and developers

Another of its functions is to assist manufacturers in understand key technical, clinical and documentary requirements that must be complied with according to the class of the device. Assessments and controls according to the risk of the medical equipment allow planning the process of development, validation, registration and market launch in an efficient and legally compliant manner..

Facilitates the work of health authorities

Regulatory authorities may prioritizing inspections and audits according to the risk associated with the product. This simplifies decision-making to authorize or restrict the use of certain devices.

Establishes trust in the marketplace and among users

Healthcare professionals and patients can be confident that they can rely on a product has been evaluated proportionally to the potential risks it represents. In this way, the promotes transparency, traceability and efficient management of incidents or product recalls.

It is a mandatory legal requirement

In most countries, classifying medical devices according to their risk is a legal requirement for approval and marketing (as in the European MDR Regulation, the FDA in the USA or the Chilean Institute of Public Health).

The classification of medical devices according to their risk is not only a regulatory procedure, but an essential tool to protect the health of patients and professionals, guarantee quality and make the entire healthcare system more efficient. If you work in the medical, technological or regulatory sector, knowing and applying this classification is the first step to ensure that your products reach the market in a safe, legal and responsible way.