Medical Device Classification Guidance (MDCG 2021-24) PDF

Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 MDCG 2021-24 Guidance on classification of medical devices October 2021 This document has been endorsed by the Medical Device Coordination Group (MDCG) establish...

Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 MDCG 2021-24 Guidance on classification of medical devices October 2021 This document has been endorsed by the Medical Device Coordination Group (MDCG) established by Article 103 of Regulation (EU) 2017/745. The MDCG is composed of representatives of all Member States and it is chaired by a representative of the European Commission. The document is not a European Commission document and it cannot be regarded as reflecting the official position of the European Commission. Any views expressed in this document are not legally binding and only the Court of Justice of the European Union can give binding interpretations of Union law. 1 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 Table of contents 1 Purpose of medical device classification........................................................................................................................................................................... 4 2 Practical relevance of classification.................................................................................................................................................................................... 4 2.1 General requirements...................................................................................................................................................................................................... 4 2.2 Conformity assessment................................................................................................................................................................................................... 5 2.3 Clinical evaluation and investigation......................................................................................................................................................................... 5 2.4 Post-market surveillance................................................................................................................................................................................................ 6 2.5 Traceability.......................................................................................................................................................................................................................... 6 2.6 Instructions for use.......................................................................................................................................................................................................... 7 3 How to carry out classification............................................................................................................................................................................................. 7 3.1 Basic terms and definitions........................................................................................................................................................................................... 7 Specific medical purpose........................................................................................................................................................................................ 7 Duration of use........................................................................................................................................................................................................... 7 Continuous use........................................................................................................................................................................................................... 8 Invasiveness................................................................................................................................................................................................................ 8 Active medical devices.......................................................................................................................................................................................... 10 Devices with a measuring function................................................................................................................................................................... 12 Systems and procedure packs........................................................................................................................................................................... 12 Other terms............................................................................................................................................................................................................... 13 3.2 Application of the classification rules....................................................................................................................................................................... 14 How to use the rules.............................................................................................................................................................................................. 15 Practical example.................................................................................................................................................................................................... 15 3.3 Handling of interpretational problems..................................................................................................................................................................... 16 2 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 4 Explanations of individual rules......................................................................................................................................................................................... 17 4.1 Graphical summary........................................................................................................................................................................................................ 17 Non-invasive devices............................................................................................................................................................................................. 17 Invasive devices...................................................................................................................................................................................................... 18 Active devices........................................................................................................................................................................................................... 22 Special rules.............................................................................................................................................................................................................. 24 4.2 General explanation of rules/practical issues/examples.................................................................................................................................. 26 Non-invasive devices............................................................................................................................................................................................. 26 Invasive devices...................................................................................................................................................................................................... 32 Active devices........................................................................................................................................................................................................... 39 Special rules.............................................................................................................................................................................................................. 47 3 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 1 Purpose of medical device classification The classification of medical devices in use by the EU medical device legislation is a risk-based system taking into account the vulnerability of the human body and the potential risks associated with the devices. This approach uses a set of criteria that can be combined in various ways in order to determine classification, e.g. duration of contact with the body, degree of invasiveness, local vs. systemic effect, potential toxicity, the part of the body affected by the use of the device and if the device depends on a source of energy. The criteria can then be applied to a vast range of different medical devices and technologies. These are referred to as the ‘classification rules’ and are set out in Annex VIII of Regulation (EU) 2017/745 on medical devices (MDR). They correspond, to a large extent, to the classification rules established by the International Medical Device Regulators Forum (IMDRF) in the guidance document GHTF/SG1/N77:20121. 2 Practical relevance of classification The purpose of this chapter is to provide a general overview on the impact of the classification of medical devices on different aspects of the device compliance with the legal requirements. The explanations provide some simplified concepts and are not exhaustive. For details see the MDR and related additional guidance2. 2.1 General requirements Irrespective of the class of the device, all devices must comply with all relevant obligations of the MDR. However, some requirements depend on the device classification. For example, the devices must:  meet the general safety and performance requirements, including the requirements regarding the information to be supplied by the manufacturer (Annex I of the MDR);  be subject to the reporting requirements under the medical device vigilance system;  be CE marked (except custom-made devices and devices intended for clinical investigation, in which case they should comply with the provisions of respectively Art. 52.8 and Annex XIII or Articles 62 – 80, 82 and Annex XV);  be assigned a Unique Device Identifier (UDI) number and be registered in the electronic system, in accordance with MDR Article 29;  if the device is implantable, be supplied with an implant card and information to the patient in accordance with Article 18. 1 http://www.imdrf.org/docs/ghtf/final/sg1/technical-docs/ghtf-sg1-n77-2012-principles-medical-devices-classification-121102.pdf 2 https://ec.europa.eu/health/md_sector/new_regulations/guidance_en 4 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 According to MDR Article 51 devices are divided into the following classes I, IIa, IIb and III, taking into account the intended purpose of the devices and their inherent risks. Classification is to be carried out in accordance with Annex VIII to the MDR. In addition, and according to Article 52(7)(a), (b) and (c), Class I devices can be further subdivided into Is – sterile condition, Im – measuring function and Ir – reusable surgical. The technical documentation3 to be drawn up by the manufacturer must include the risk class of the device and the justification for the classification rule(s) applied in accordance with Annex VIII of the MDR. Sections 2.2-2.6 give an overview of some requirements that depend on the class of the device. For detailed and exhaustive provisions on each topic, refer to the MDR, as well as to dedicated guidance where available4. Annex XVI products should be classified in accordance with the classification rules in Annex VIII of the MDR and taking into account possible provisions within the relevant implementing acts covering Annex XVI devices. 2.2 Conformity assessment Conformity assessment is the process demonstrating whether the requirements of the MDR relating to a device have been fulfilled. Demonstrating conformity is in the first instance the responsibility of the manufacturer and for most devices classes the conformity is then assessed by a notified body. The higher the class of the device, the greater the involvement of a notified body in conformity assessment. Annex I (general safety and performance requirements) and Annexes II (technical documentation) and III (technical documentation on post-market surveillance) apply to all devices regardless of class. Further relevant conformity assessment procedures (laid down in Annexes IX to XI) will depend on the class of the device. For some classes, the manufacturer has a choice of more than one procedure. Conformity assessment is described in MDR Article 52. Custom-made or investigational devices falling into any class have their own provisions: Annex XIII for custom-made devices and Article 82 for investigational devices. For class III implantable custom-made devices, the manufacturer also needs to apply either Chapter I of Annex IX or Part A of Annex XI. 2.3 Clinical evaluation and investigation For any device regardless of class, the manufacturer must ensure the general safety and performance requirements are satisfied (MDR Article 5, MDR Annex I). This includes carrying out a clinical evaluation (MDR Article 5 (3), MDR Article 61, MDR Annex XIV. For implantable devices and class III devices, a premarket clinical investigation is compulsory, with some exceptions such as modifications of an existing device, demonstrated equivalence to CE-marked device, placed on the market under Directive 90/385/EEC or Directive 93/42/EEC for which sufficient clinical data is already available, and specific exemptions laid down in Article 61(6)(b). The conditions for starting a clinical investigation vary 3 Annex II 1.1 (f) MDR 4 https://ec.europa.eu/growth/sectors/medical-devices/new-regulations/guidance_en 5 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 depending on the class of the device (see MDR Article 70(7) and Article 78). According to Article 61(10), if demonstration of conformity with Annex I requirements based on clinical data is not deemed appropriate, the manufacturer shall justify this in the technical documentation. For class III implantable devices and class IIb active devices intended to administer or remove a medicinal product, the notified body must also follow the clinical evaluation consultation procedure where certain documentation including the clinical evaluation report is submitted for review by expert panels (MDR Article 54 and Section 5.1 of Annex IX). It must notify the Member State competent authorities of the certificates it has granted for these types of devices (MDR Article 55). The manufacturer may consult an expert panel on their clinical development strategy prior to performing the clinical evaluation and/or investigation (MDR Article 61(2)). See also MDCG Guideline 2019-35 for interpretation of Article 54. For implantable devices and class III devices, other than custom-made or investigational devices, the manufacturer must update the post- market clinical follow-up evaluation report as it will serve an input for the writing of the Periodic Safety Update Report, and, if indicated, the summary of safety and clinical performance6 (MDR Article 32). 2.4 Post-market surveillance The manufacturer must update the clinical evaluation with clinically relevant information coming from post-market surveillance, in particular the post-market clinical follow-up. For class I devices, including sterile, those with a measuring function and the reusable surgical instruments, the manufacturer must prepare and maintain a post-market surveillance report (MDR Article 85), which must be made available to the competent authorities on request. For class IIa, IIb and III devices, the manufacturer must prepare a periodic safety update report for each device, and, where relevant, for each category or group of devices (MDR Article 86). This report must be updated at least annually for class IIb and III devices and at least every two years for class IIa devices. 2.5 Traceability For class III implantable devices, economic operators and health institutions are obliged to have a record of the UDI of the devices they have supplied or with which they have been supplied (MDR Article 27). For class II and III devices, the economic operator is obliged to provide information on the Member State(s) where the device is, or is to be, made available when registering the device (Annex VI Part A 2.4). In the case of implantable and class III devices, the economic operator must provide the summary of safety and clinical performance (Annex VI Part A 2.14). For single-use class I and IIa devices packaged and labelled individually, the UDI carrier does not have to appear on the packaging but must appear on a higher level of packaging (Annex VI Part C 4.3). 5 MDCG 2019-3 https://ec.europa.eu/health/sites/default/files/md_sector/docs/md_mdcg_2019_3_rev1_cecp_en.pdf 6 MDCG 2019-9 https://ec.europa.eu/health/sites/health/files/md_sector/docs/md_mdcg_2019_9_sscp_en.pdf 6 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 However, if the healthcare provider does not have access to the higher level of packaging, the UDI carrier must appear on the individual device packaging. 2.6 Instructions for use Generally, instructions for use must be supplied together with the device. By way of exception, class I and IIa devices may be supplied without instructions for use if such devices can safely be used without the instructions and no other provisions of Annex I Section 23 state otherwise. 3 How to carry out classification This section is aimed at presenting definitions and terms useful for the application of the classification principles and rules. 3.1 Basic terms and definitions Relevant definitions in respect to the classification of devices are set out in Article 2 and Chapter I of Annex VIII of the MDR but the Regulation also contains explanation of further terms. These relevant terms and definitions for this guidance are collected below. Specific medical purpose The specific medical purpose is specified by the manufacturer from those listed in the indents of Article 2(1) MDR. Duration of use Transient Normally intended for continuous use for less than 60 minutes. Short term Normally intended for continuous use for between 60 minutes and 30 days. Long term Normally intended for continuous use for more than 30 days. 7 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 In certain instances the duration of use for a product needs to be considered as the duration of effect. For instance, application of a topical cream to the skin may only take seconds to apply but the cream may remain in situ for many hours. The duration of use should therefore not be considered as the time taken to apply the product but rather the duration for which the product remains in or on the body. Continuous use In calculating the duration referred to in Section 1 of Chapter I of Annex VIII of MDR, continuous use means: ‘(a) The entire duration of use of the same device without regard to temporary interruption of use during a procedure or temporary removal for purposes such as cleaning or disinfection of the device. Whether the interruption of use or the removal is temporary shall be established in relation to the duration of the use prior to and after the period when the use is interrupted or the device removed; and (b) the accumulated use of a device that is intended by the manufacturer to be replaced immediately with another of the same type.’ For example, a scalpel may be used on the same patient throughout an operation that may last for several hours. The uninterrupted use for an intended purpose, i.e. cutting tissue, will normally not last for more than a few seconds at a time. Therefore a scalpel is a transient use device. However, where usage of a device is discontinued in order for the device to be replaced immediately by the same or an identical device (e.g. replacement of a ureteric catheter) this shall be considered an extension of the continuous use of the device. As another example, the overnight period when contact lenses are cleaned and disinfected is considered as a discontinuation of the device use. For the determination of the duration of use, only the specified time period of uninterrupted wear of the lens (e.g. 16 hours) needs to be taken into account7. If it cannot be demonstrated that components of the device are totally discontinued in the interval between uses, this is also considered as an immediate replacement and an extension of the continuous use of the device. Invasiveness Invasive device Any device which, in whole or in part, penetrates inside the body, either through a body orifice or through the surface of the body. A device that administers energy to the body should not be considered as invasive if only energy it emits penetrates the body and not the device itself. Body orifice Any natural opening in the body, as well as the external surface of the eyeball, or any permanent artificial opening, such as a stoma. 7 MDR Annex VIII 3.6 8 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 Injured skin or mucous membrane8 An area of skin or a mucous membrane presenting a pathological change or change following disease, a wound or a scar. Surgically invasive device9 An invasive device which penetrates inside the body through the surface of the body, including through mucous membranes of body orifices with the aid or in the context of a surgical operation; and a device which produces penetration other than through a body orifice. The term surgical operation used in this definition includes all clinical interventional procedures in which a device is placed into the body through the surface of the body. A surgically invasive device always implies that it enters through an artificially created opening. This can be a large opening, such as a surgical incision, or it can be a pinprick opening made by a needle. Therefore surgical gloves and needles used with syringes are surgically invasive. In this context the following should be noted:  a surgically created stoma used in urostomy, colostomy and ileostomy or permanent tracheostomy is considered to be a body orifice; therefore devices introduced into such a stoma are not surgically invasive.  in contrast, a surgically created opening to allow access to the circulatory system should not be considered to be a body orifice. Devices introduced into such an opening are surgically invasive. The concept of surgically invasive should be understood to cover also liquids that are in invasive contact with organs, tissues or other parts of the body if the access for such liquids is through a surgically created opening. For a device that administers a substance, such a substance must be assessed in its own right (e.g. substances administered by a jet injector). Reusable surgical instrument10 An instrument intended for surgical use in cutting, drilling, sawing, scratching, scraping, clamping, retracting, clipping or similar procedures, without a connection to an active device and which is intended by the manufacturer to be reused after appropriate procedures such as cleaning, disinfection and sterilisation have been carried out. Implantable device11 Any device, including those that are partially or wholly absorbed, which is intended: — to be totally introduced into the human body, or — to replace an epithelial surface or the surface of the eye, by clinical intervention and which is intended to remain in place after the procedure. 8 MDR Annex VIII 2.8 9 MDR Annex VIII 2.2 10 MDR Annex VIII 2.3 11 MDR Article 2 (5) 9 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 Any device intended to be partially introduced into the human body by clinical intervention and intended to remain in place after the procedure for at least 30 days shall also be deemed to be an implantable device. A ‘procedure’ must be understood in this context to include the surgical procedure during which the implant is placed into the body and the immediate post-operative care that is associated with the procedure. The ‘procedure’ does not extend to the conclusion of the therapeutic treatment, e.g. the removal of an implant must be considered to be another ‘procedure’. Thus a plate used to fix a fractured bone and which remains in place after the procedure for at least 30 days is an implant even if it is taken out after the fracture has healed. In this case the placing of the plate and its explantation are two different surgical procedures. Sometimes partially implanted devices are deemed to be implants. For instance, if an operation is carried out specifically to place an infusion port into the body which would remain in place for at least 30 days after the procedure, such an infusion port would be an implant. However, a non-tunnelled central venous catheter which is intended for use for temporary vascular access and intended to be removed after 7 – 10 days is not an implantable device. Nor would a suture used for skin wound closure that is intended to be taken out prior to 30 days be considered an implant. Critical anatomical locations For the purposes of the MDR, ‘Central circulatory system’12 means the following blood vessels: arteriae pulmonales, aorta ascendens, arcus aortae, aorta descendens to the bifurcatio aortae, arteriae coronariae, arteria carotis communis, arteria carotis externa, arteria carotis interna, arteriae cerebrales, truncus brachiocephalicus, venae cordis, venae pulmonales, vena cava superior and vena cava inferior. For the purposes of the MDR, ‘Central nervous system’13 means the brain, meninges and spinal cord. Active medical devices 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. Devices intended to transmit energy, substances or other elements between an active device and the patient, without any significant change, shall not be deemed to be active devices14. The concept act by converting energy includes conversion of energy in the device and/or conversion at the interface between the device and the tissues or in the tissues. Electrodes intended for E.C.G. or E.E.G are normally not considered active devices because they do not normally act by conversion of energy. 12 MDR Annex VIII 2.6 13 MDR Annex VIII 2.7 14 MDR Article 2 (4) 10 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 The application of energy from the human body for the purpose of operating a device does not make the device ‘active’ unless that energy is stored within the device for subsequent release. For instance, energy generated by human muscle and applied to the plunger of a syringe (thus causing a substance to be delivered to a patient) does not make this syringe an active device. However, if a drug delivery system depends upon manual winding to preload a spring which is subsequently released to deliver a substance, then the device incorporating the spring is an active device. Another example of an active device are elastomeric pumps, where the energy from the human body is stored in the stretched elastomer layer. Medical devices using prestored gases and/or vacuum as a power source are regarded as active devices, as long as they fulfil both the criteria under the definition e.g. gas mixers with anaesthesia machines, aerosol pain relief sprays with a pre-stored propellant gas supply and gas-powered suction pumps. Heating/cooling pads intended only to release stored thermal energy are not active devices because they do not act by conversion of energy. However, heating/cooling pads which act by chemical action (e.g. exothermic or endothermic reaction) are active devices as they are converting chemical energy into heat and/or vice versa. The concept of significant change for energy includes changes in the nature, level and density of energy (see Rule 9). This means that for instance an electrode is not considered an active device under this classification system as long as the energy input is intended to be the same as the energy output. Resistance in a wire that causes minor changes between input and output cannot be considered to constitute ‘significant change’. However, electrodes used in electrosurgery for cutting tissues or cauterisation are active devices because their operation depends on energy provided by a generator and their action is achieved by conversion of energy at the interface between the device and the tissue or in the tissue. Software is also an active device13. Software should be reviewed not only in the context of Rule 1115. Active therapeutic device means any active device used, whether alone or in combination with other devices, to support, modify, replace or restore biological functions or structures with a view to treatment or alleviation of an illness, injury or disability. 16 Active device intended for diagnosis and monitoring means any active device used, whether alone or in combination with other devices, to supply information for detecting, diagnosing, monitoring or treating physiological conditions, states of health, illnesses or congenital deformities17. A device is considered to allow direct diagnosis when it provides the diagnosis of the disease or condition in question itself or when it provides decisive information for the diagnosis18. 15 MDCG 2019-11 https://ec.europa.eu/health/sites/health/files/md_sector/docs/md_mdcg_2019_11_guidance_qualification_classification_software_en.pdf 16 MDR Annex VIII 2.4 17 MDR Annex VIII 2.5 18 MDR Annex VIII 3.7 11 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 Devices with a measuring function The following criteria, if fulfilled together, indicate that a device has a measuring function: a) The device is intended by the manufacturer to measure: - quantitatively a physiological or anatomical parameter, or - a quantity or a quantifiable characteristic of energy or of substances (including medicinal products) delivered to or removed from the human body. Spoons or plastic syringes co-packed with medicinal products and used to measure a quantity of that medicinal product to be administered to the patient are in this category. Devices for the delivery of liquid to the human body without graduation or scale (e.g. medicine spoons, cups, droppers without graduation or scale or display of measuring unit) are not in this category19. b) The result of the measurement: - is displayed in legal units or other acceptable units within the meaning of Directive 80/181/ECC20, or - is compared to at least one point of reference indicated in legal units or other acceptable units in compliance with the mentioned directive.. c) The intended purpose implies accuracy, claimed explicitly or implicitly, where a non-compliance with the implied accuracy could result in a significant adverse effect on the patient’s health and safety. The expression ‘claimed implicitly’ covers cases where the user, on the basis of the designation of the device or of its accompanying documents, or on the basis of the common use, is entitled to expect accuracy where the accuracy of the measurement has an impact on the diagnosis or therapy of the patient. Measuring activities during the manufacturing process including those for calibration purposes are not covered and do not imply a measuring function of the manufactured device. Systems and procedure packs System and procedure packs is described in MDR Article 22. They can combine medical devices, in vitro diagnostic medical devices, and other products which are in conformity with legislation that applies to those products, only where they are used within a medical procedure or their presence in the system or procedure pack is otherwise justified. In this case of demonstrated legal conformity of each component, the systems or procedure packs no not need to bear themselves an additional CE marking but they must bear the name, registered trade name or registered trade mark of the person who combines the products as well as the address at which that person can be contacted. 19N.B. they are qualified as devices. 20Council Directive 80/181/EEC of 20 December 1979 on the approximation of the laws of the Member States relating to units of measurement and on the repeal of Directive 71/354/EEC (OJ L 39, 15.2.1980, p. 40 ). 12 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 A procedure pack means a combination of products packaged together and placed on the market with the purpose of being used for a specific medical purpose21. A system means a combination of products, either packaged together or not, which are intended to be interconnected or combined to achieve a specific medical purpose22. Where the system or procedure pack incorporates devices which do not bear the CE marking or where the chosen combination of devices is not compatible in view of their original intended purpose, or where the sterilisation has not been carried out in accordance with the manufacturer's instructions the system or procedure pack shall be treated as a device in its own right and shall be subject to the relevant conformity assessment procedure pursuant to MDR Article 52. The classification is determined by the intended use of the system or procedure pack. The natural or legal person that combines the devices must assume the obligations incumbent on manufacturers. For such combinations, including different devices, the classification is normally determined by the intended use. In those cases where the intended use of the final device is not specific enough to determine the classification, the classification of the device is at the level of the highest classified device included, taking into account the new intended use of the device. Other terms This section gives notes on other terms used in Annex VIII of the MDR: Systemic absorption: The process by which substances or their metabolites enter the body (e.g. by crossing mucous membranes) and are distributed into the body via the blood and/or lymphatic system. Wholly or mainly absorbed: The term ‘absorption’ in the context of implantable devices refers to the degradation of a material within the body and the metabolic elimination of the resulting degradation products from the body. It does not apply to those substances that are excreted without modification from the body, e.g. insufflation gases for the abdominal cavity or laparoscopic and endoscopic procedures. Local dispersion: The condition by which substances remain in a specific site without being distributed into the body via the blood and/or lymphatic system. Medicine / medicinal product: According to the definition given in Directive 2001/83/EC: ‘(a) Any substance or combination of substances presented as having properties for treating or preventing disease in human beings; or (b) Any substance or combination of substances which may be used in or administered to human beings either with a view to restoring, correcting or modifying physiological functions by exerting a pharmacological, immunological or metabolic action, or to making a medical diagnosis.’ 21 MDR article 2(10) 22 MDR article 2(11) 13 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 A ‘nanomaterial’ means a natural, incidental or manufactured material containing particles in an unbound state or as an aggregate or as an agglomerate and where, for 50% or more of the particles in the number size distribution, one or more external dimensions is in the size range 1-100 nm; Fullerenes, graphene flakes and single-wall carbon nanotubes with one or more external dimensions below 1 nm shall also be deemed to be nanomaterials according to MDR, Article 2(18). Related definitions on ‘particle’, ‘agglomerate’ and ‘aggregate’ are also included in the MDR Article 2(19-21). The definitions on nanomaterial and the related terms were taken from Commission Recommendation 2011/696/EU on the definition of nanomaterials23. Guidance on terms and concepts used in the definition can be found in a report from the European Commission’s Joint Research Centre.24 Derivative means a non-cellular substance extracted from human or animal tissue or cells through a manufacturing process. The final substance used for manufacturing of the device in this case does not contain any cells or tissues. 3.2 Application of the classification rules Before applying the classification rules, the manufacturer should first determine if the product concerned, based on its specific medical purpose, falls in the scope of the MDR as medical device, accessory for a medical device (Article 2 MDR), medical device part or component for replacement (Article 23(2) MDR) or as a device without an intended medical purpose listed in Annex XVI. It is the intended and not the accidental use of the device that determines the class of the device. For instance, a suture organiser that is intended to keep suture threads used in open heart surgery in the correct order should not be considered as an invasive device if it is intended to be kept outside the patient. Similarly, if a healthcare professional or others uses the device in a manner not intended by the manufacturer, this does not change the class of the device for the purpose of conformity assessment. However, if the normal clinical use of the device changes in time with evolving clinical practice such that the intended purpose and classification of the device changes, this should be addressed by the manufacturer and the conformity of the device assessed for the new intended purpose. It is the intended purpose assigned by the manufacturer to the device that determines the class of the device and not the class assigned to other similar products. For instance, two sutures that have the same composition may well have different intended purposes. In case several rules, or if, within the same classification rule, several sub-rules, apply to the same device based on the device intended purpose, the strictest rule and sub-rule resulting in higher classification will apply. In terms of further clarification of the classification rules, the elements listed below should also be considered. 23 https://ec.europa.eu/environment/chemicals/nanotech/faq/definition_en.htm 24 Rauscher et al., An overview of concepts and terms used in the European Commission’s definition of nanomaterial, EUR 29647 EN, European Commission, JRC, Ispra, 2018,ISBN 978-92-79-99660-3, doi: 10.2760/459136, JRC 113469 14 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 How to use the rules The manufacturer must take into consideration all the rules in order to establish the proper classification for its device. The strictest rule and sub-rule resulting in the highest classification determines the class25. It is quite conceivable for instance that one of the general rules that is not specific to active devices nevertheless applies to such a device. The intended purpose and all the device characteristics must be taken into consideration. The characteristic or combination of characteristics in accordance with the intended purpose of the device that falls into the highest class determines the class for the device as a whole. In addition to the classification rules set out in Annex VIII of MDR, the manufacturers must also take account of any applicable legal acts and consider guidance documents which may support the classification of their device. Practical example A simple wound drainage system has usually three components that must be taken into consideration: the cannula, the tubing and the collector unit. If the system is sold without a cannula, then the classification of the cannula does not need to be taken into account. It is assumed here that the system is used for short term duration, i.e. that uninterrupted intended use is more than 60 minutes and less than 30 days. It is furthermore assumed that the collected liquids are not intended to be reinfused into the body nor reprocessed for eventual reinfusion and that the device is not intended to be connected to a powered suction system. Intended uses Rule Class Surgically invasive cannula to reach a wound site in the pleural cavity to drain the cavity 7 IIa Non-invasive tubing to evacuate body liquids towards the collector. 1 I Non-invasive collector to receive the body liquids. 1 I The clear conclusion here is that the manufacturer would have a choice of applying class IIa to the whole device or carrying out separate conformity assessment procedures for the cannula on one hand and the tubing and collector on the other hand. 25 MDR Annex VIII 3.5 15 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 3.3 Handling of interpretational problems It is recognised that although the existing rules will adequately classify the vast majority of existing devices, a small number of devices may be more difficult to classify. As soon a notified body needs to be involved, any dispute between the manufacturer and the notified body concerned, arising from the application of Annex VIII, may be referred for a decision to the competent authority of the Member State in which the manufacturer (or its authorized representative) has its registered place of business. In cases where the manufacturer has no registered place of business in the Union and has not yet designated an authorised representative, the matter shall be referred to the competent authority of the Member State in which the authorised representative referred to in the last indent of point (b) of the second paragraph of Section 2.2 of Annex IX has its registered place of business. Where the notified body concerned is established in a Member State other than that of the manufacturer, the competent authority must adopt its decision after consultation with the competent authority of the Member State that designated the notified body. The competent authority of the Member State in which the manufacturer has its registered place of business will notify the MDCG and the Commission of its decision. The decision can be made available upon request26. Outside this regulatory procedure, competent authorities may refer on an ad hoc and voluntary basis complex classification cases for discussion at the Borderline and Classification Working Group of the MDCG. Agreement positions on classification reached by this Working Group are published for reference in the Manual on Borderline and Classification. 26 Article 51 MDR 16 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 4 Explanations of individual rules 4.1 Graphical summary Non-invasive devices NON-INVASIVE DEVICES Rule 2 intended for Rule 3 modifying the channelling or storing blood, biological or chemical composition of human tissues Rule 4 in contact with injured body liquids, cells or tissues, skin or mucous membrane Rule 1 either do not touch liquids or gases for The or cells, blood, other body (Also for invasive devices the patient or contact only liquids or other liquids intact skin pupose of eventual infusion, into contact with injured administration or intended for implantation or mucous membrane) introduction into the body administration into the body I I IIb IIa unless unless OR OR OR OR OR OR OR OR Consisting of a substance or a mixture For use with blood, Connected to a of substances intended Only filtration, As mechanical Intended for other body fluids, active device in bloodbags to be used in vitro in Intended to manage centrifugation barrier, compression wounds which organs , tissues, cells class IIa or higher direct contact with micro-environment or exchange of or absorbation breach dermis and gas or heat human cells, tissues or of injured skin or heal only by organs taken from the exudates mucous membrane secondary intent human body or used in vitro with human IIa IIa IIb embryos before their IIa implantation or I IIa IIb administration into the body III ATTENTION: to special rules (14 to 22) 17 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 Invasive devices Invasive devices C Rule 4 in contact with Rule 20 invasive in injured skin or mucous respect to body orifices membrane (not surgical) to (Also for invasive administer medicinal devices into contact with Rule 5 ATTENTION products by inhalation injured mucous Invasive in body orifice or take note of membrane) stoma ( not surgically) rule 4, 20 and 21 Rule 21 composed of substances or of combinations of substances to be introduced into the human body via a body orifice or applied to the skin are OR absorbed by or locally dispersed OR OR OR Connected to an in the human body active medical device in class IIa or higher Transient use Short term use Long term use IIa I IIa IIb OR OR If only oral cavity, If ony in oral cavity, in ear in ear canal or in canal or in nasal cavity nasal cavity and not liable to be absorbed by the mucous membrane I IIa 18 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 Invasive devices Rule 4 for invasive Rule 6 devices that come into surgically invasive- ATTENTION contact with injured transient use mucous membrane. IIa unless OR OR OR OR OR OR Intended to administer Intended specifically for Intended specifically to Intended to supply Biological effect- Reusable surgical medicines in a use in direct contact control/diagnose/monitor/ energy/ ionizing mainly or wholly instrument potentially hazardous with the heart or central correct a defect or heart or radiation absorbed manner circulatory system or central circulatory system central nervous system through direct contact IIb IIb IIb I III III 19 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 Invasive devices Rule 7 Surgically invasive- Short term use IIa unless OR OR OR OR OR OR Intended specifically to Intended to Intended to supply Biological effect- Intended for use in direct Intended to undergo monitor/ control/ administer energy / ionizing mainly or wholly contact with the central chemical change in diagnose/correct defect medicines (NOT in radiation absorbed nervous system or the heart body- (NOT in teeth) of heart or central teeth) circulatory system – by or the central circulatory direct contact system IIb III IIb IIb III III 20 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 Invasive devices Rule 8 Surgically invasive Long term use and implantable devices IIb unless OR OR OR OR OR OR OR OR OR Intended to be used in Intended to Spinal disc biological effect Intended to undergo Active implantable Intended to be direct conatct with heart administer Breast implants, total or partial joint replacement or or are wholly or Chemical change in devices or their placed in teeth or central circulatoiry/ medicinal surgical meshes, replacement, implants in contact mainly absorbed body (NOT in teeth) accessoires nervous system products with spinal column IIa III III III III III III III III OR except components such as screws, wedges, plates and instruments IIb 21 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 Active devices ACTIVE DEVICES Rule 10 ATTENTION Active devices for diagnosis and monitoring or suppling Rule 9 Rule 22 Active therapeutic energy to be absorbed by the Active therapeutic devices devices with an integrated or incorporated diagnostic function body or to image in vivo intended to administer or exchange energy which significantly determines distribution of the patient management by the radiopharmaceuticals or allowing device, such as closed loop direct diagnosis or monitoring systems or automated external defibrillators of vital physiological processes IIa IIa III unless OR OR OR OR All devices emitting ionizing radiation for diagnostic or Specifically intended to are intended for unless except for devices monitor vital physiological diagnosis in clinical intended to illuminate therapeutic radiology. Including interventional radiology parameters where variations situations where the the patient's body, in could result in immediate patient is in the visible spectrum devices and devices which control or monitor such devices danger to the patient immediate danger I IIb IIb IIb OR OR OR OR Intended to control or monitor intended to emit ionizing or influence directly the radiation for therapeutic intended for performance of a class IIb purposes, and devices which controlling, monitoring Administer or active therapeutic device, control or monitor such or directly influencing the exchange energy devices, or which directly performance of active in a potentially influence their performance implantable devices hazardous way IIb IIb IIb III 22 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 ACTIVE DEVICES Rule 11 Software Rule 12 Active devices to administer and/or remove Rule 13 medicines & other All other active substances from the body devices I unless intended to provide IIa I information used to take decisions with monitor physiological diagnosis or processes unless therapeutic purposes, If this is a potentialy IIa hazardous way IIa OR IIb OR OR for monitoring of vital physiological parameters, Decision impact can where the nature of parameter cause serious Decision impact can variations could result in deterioration in cause death or immediate danger to the health or surgical irreversible patient intervention deteriation of health IIb III IIb 23 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 Special rules SPECIAL RULES Rule 16 Rule 18 devices intended Devices utilizing non-viable Rule 14 Rule 15 specifically to be used Rule 17 human or animal tissues, cells Devices incorporating devices used for Devices intended for for disinfecting or recording of X-Ray or their derivatives (unless integral medicinal contraception or such devices intended to prevention of sexually sterilising medical diagnostic images substance and that has an come into contact with intact action ancillary to that of transmitted diseases devices skin only) the devices IIa IIa III IIb III unless unless OR OR specifically intended implantable or for disinfecting, long-term invasive cleaning, rinsing or Disinfecting solutions or hydrating contact washer solutions specifically to lenses be used for disinfecting invasive devices, as the end point of processing III IIb IIb 24 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 SPECIAL RULES Rule 20 devices Rule 22 Active therapeutic devices Rule 19 devices invasive in respect to with an integrated or incorporated incorperating or body orifices (not diagnostic function which significantly consisting surgical) to administer Rule 21 devices composed of determines the patient management Nanomaterials medicinal products by substances or of combinations of by the device, such as closed loop inhalation substances to be introduced into the systems or automated external human body via a body orifice or applied defibrillators to the skin and absorbed by or locally dispersed in the human body IIa OR OR OR unless negligible III low potential high or medium OR OR potential for internal potential for for internal IIb exposure internal exposure intended to exposure mode of action has an essential impact on the treat life- efficacy and safety of the threatening administered medicinal conditions, IIa IIb III product OR OR OR IIb IIb If they applied to the skin if they, or their products if they achieve their intended or in the nasal or oral of metabolism, are purpose in the stomach or cavity as far as the systemically absorbed lower gastrointestinal tract pharynx and achieve by the human body in and they, or their products of their intended purpose on order to achieve the metabolism, are systemically those cavities; intended purpose absorbed by the human body IIa III III 25 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 4.2 General explanation of rules/practical issues/examples The examples provided do not imply that the products are a priori qualified as devices. Classification rules apply after the qualification of the device has been established. Non-invasive devices Rule 1 - Devices that either do not come in direct contact with the patient or contact intact skin1 only General explanation of the rule This is a fall-back rule applying to all devices that are not covered by a more specific rule. This is a rule that applies in general to devices that come into contact only with intact skin or that do not come in direct contact with the patient. Class Rule 1 Examples I All non-invasive devices are classified as class I, unless one of the rules set out  Devices intended in general for external patient support hereinafter applies (e.g. hospital beds, patient hoists, walking aids, wheelchairs, stretchers, dental patient chairs)  Body liquid collection devices intended to be used in such a way that a return flow is unlikely (e.g. to collect body wastes such as urine collection bottles, incontinence pads or collectors used with wound drainage devices). They may be connected to the patient by means of catheters and tubing  Devices used to immobilise body parts and/or to apply force or compression on them (e.g. non-sterile dressings used to aid the healing of a sprain, plaster of Paris, cervical collars, gravity traction devices, compression hosiery)  Corrective spectacle frames (i.e. glasses) and lenses in frames  Stethoscopes  Eye occlusion plasters  Incision drapes  Non-invasive conductive gels i.e. ultrasound gels2  Non-invasive electrodes (electrodes for EEG or ECG)  Permanent magnets for removal of ocular debris  Wheelchairs pushed by hand 26 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 Practical issues of classification Some non-invasive devices are indirectly in contact with the body and can influence internal physiological processes by storing, channelling or treating blood, other body liquids or liquids which are returned or infused into the body or by generating energy that is delivered to the body. These are handled by other rules because of the hazards inherent in such indirect influence on the body. Note 1: Intact skin includes the skin around an established stoma unless the skin is breached. Signs of breached skin include, but not limited to, tears, erythema, oedema, weeping and infection. The definition of intact skin must apply for the continuous use of the device. Note 2: Ultrasound gels are not to be absorbed or locally dispersed within the body at the site of action in order to achieve their intended purpose. Rule 2 - Channelling or storing for eventual administration General explanation of the rule This rule applies to non-invasive devices intended for channeling or storing blood, body liquids, cells or tissues, liquids or gases for specific purposes. Invasive devices, other than surgically invasive devices which are intended to administer medicinal products by inhalation, fall under the Rule 20 These types of devices should be considered separately from the non-contact devices of Rule 1 because they may be indirectly invasive. They channel or store substances that will eventually be administered to the body. Typically these devices are used in transfusion, infusion, extracorporeal circulation and delivery of anaesthetic gases and oxygen. In some cases devices covered under this rule are very simple delivery devices that rely on gravity. Class Rule 2 Examples IIa All non-invasive devices intended for channeling or storing blood, body liquids, cells or tissues,  Devices intended to be used as channels in liquids or gases for the purpose of eventual infusion, administration or introduction into the active drug delivery systems, e.g. tubing body are classified as class IIa: intended for use with an infusion pump - if they may be connected1 to a class IIa, class IIb or class III active device; or if they are  Devices used for channelling gases, e.g. intended for use for channeling or storing blood or other body liquids or for storing organs, antistatic tubing for anaesthesia, anaesthesia parts of organs or body cells and tissues, breathing circuits  Syringes for infusion pumps  Devices intended to channel blood (e.g. in transfusion, extracorporeal circulation)  Devices intended for temporary storage and transport of organs for transplantation (i.e. containers, bags) 27 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24  Devices intended for long term storage of biological substances and tissues such as corneas, sperm, human embryos, etc. (i.e. containers, bags)  Fridges/freezers specifically intended for storing blood, tissues etc.  Tubings/blood lines for extracorporeal treatment (dialysis and apheresis therapies) IIb - except for blood bags; blood bags are classified as class IIb.  Blood bags without a substance which, if used separately, can be considered to be a medicinal product I In all other cases, such devices are classified as class I  Non-invasive devices that provide a simple channelling function, with gravity providing the force to transport the liquid, e.g. administration sets for infusion  Devices intended to be used for a temporary containment or storage function, e.g. cups and spoons specifically intended for administering medicines2 Empty syringes without needles Practical issues of classification If a device, e.g. tubing, intended to be used for a purpose that would require it to be connected to an active device, such a device will be automatically in class IIa, unless the manufacturer clearly states that it should not be connected to an active device of class IIa or higher. Note 1: ‘May be connected to an active device’ - such a connection is deemed to exist between a non-active device and an active device where the non-active device forms a link in the transfer of the substance between the patient and the active device and the safety and performance of one of the devices is influenced by the other device. For instance, this applies to tubing in an extracorporeal circulation system which is downstream from a blood pump and in the same blood flow circuit, but not directly connected to the pump. Note 2: See also Chapter 3.1.6 regarding the possible measuring function. 28 Medical Devices Medical Device Coordination Group Document MDCG 2021- 24 Rule 3 Devices that modify biological or chemical composition of human tissues or cells, blood, other body liquids or other liquids intended for implantation or administration into the body General explanation of the rule These types of devices must be considered separately from the non-contact devices of Rule 1 because they are indirectly invasive. They modify substances that will eventually be administered into the body. This rule covers mostly the more sophisticated elements of extracorporeal circulation sets, dialysis systems and autotransfusion systems as well as devices for extracorporeal treatment of body fluids which may or may not be immediately reintroduced into the body, including cases where the patient is not in a closed loop with the device. This rule covers also substances in direct contact with human cells, tissues or organs in vitro before their implantation or administration, without substances derived from human or animal origin such as human albumin. Class Rule 3 Examples IIb All non-invasive devices intended for modifying the biological or chemical composition of human  Devices intended to remove undesirable tissues or cells, blood, other body liquids or other liquids intended for implantation or substances out of the blood by exchange of administration into the body are classified as class IIb, solutes such as hemodialysers  Devices intended to separate cells by physical means, e.g. gradient medium for sperm separation  Haemodialysis concentrates  D