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.

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 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).

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.

3.1.1 Specific medical purpose

The specific medical purpose is specified by the manufacturer from those listed in the indents of Article 2(1) MDR.

3.1.2 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.

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.

3.1.3 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.

3.1.4 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.

Injured skin or mucous membrane:
An area of skin or a mucous membrane presenting a pathological change or change following disease, a wound or a scar.

Surgically invasive device:
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 instrument:
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 device:
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.

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’ 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’ means the brain, meninges and spinal cord.

3.1.5 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 devices.

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.

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 device. Software should be reviewed not only in the context of Rule 11.

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.

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 deformities. 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 diagnosis.

3.1.6 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 category.

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.

3.1.7 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.

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 purpose. 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 purpose.

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.

3.1.8 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.’

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.

3.2.1 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.

3.2.2 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.

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 request.

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.

中文翻译

1 医疗器械分类的目的

欧盟医疗器械法规采用的医疗器械分类系统是一个基于风险的体系,考虑了人体的脆弱性以及与器械相关的潜在风险。该方法使用一系列可以以不同方式组合的标准来确定分类,例如与人体接触的持续时间、侵入程度、局部与系统性作用、潜在毒性、器械使用影响的身体部位以及器械是否依赖能量源。这些标准可以应用于各种不同的医疗器械和技术。这些被称为”分类规则”,在医疗器械法规(EU) 2017/745 (MDR)附录VIII中有详细规定。这些规则在很大程度上与国际医疗器械监管者论坛(IMDRF)在指导文件GHTF/SG1/N77:2012中制定的分类规则相对应。

2 分类的实际意义

本章的目的是概述医疗器械分类对器械合规性各个方面的影响。这些解释提供了一些简化的概念,并非详尽无遗。详细内容请参见MDR及相关补充指南。

2.1 一般要求

无论器械属于哪个类别,所有器械都必须符合MDR的所有相关义务。但是,某些要求取决于器械的分类。

例如,器械必须:

• 满足通用安全和性能要求,包括制造商提供信息的要求(MDR附录I);
• 遵守医疗器械警戒系统下的报告要求;
• 加贴CE标志(定制器械和用于临床研究的器械除外,这些器械应分别遵守第52.8条和附录XIII或第62-80条、第82条和附录XV的规定);
• 根据MDR第29条分配唯一器械标识(UDI)号码并在电子系统中注册;
• 如果是植入性器械,则必须根据第18条提供植入卡和患者信息。

开始临床研究的条件因器械类别而异(参见MDR第70(7)条和第78条)。根据第61(10)条,如果认为基于临床数据证明符合附录I要求不适当,制造商应在技术文件中说明理由。

对于III类植入性器械和用于给药或去除药物的IIb类有源器械,公告机构还必须遵循临床评价咨询程序,将包括临床评价报告在内的某些文件提交专家小组审查(MDR第54条和附录IX第5.1节)。公告机构必须将其为这些类型器械颁发的证书通知成员国主管部门(MDR第55条)。制造商可以在进行临床评价和/或研究之前就其临床开发策略咨询专家小组(MDR第61(2)条)。另请参见MDCG指南2019-3关于第54条的解释。

对于植入性器械和III类器械(定制或研究用器械除外),制造商必须更新上市后临床跟踪评价报告,因为它将作为编写定期安全更新报告的输入,并在需要时用于编写安全和临床性能总结(MDR第32条)。

2.4 上市后监督

制造商必须使用来自上市后监督的临床相关信息更新临床评价,特别是上市后临床跟踪。

对于I类器械(包括无菌、具有测量功能和可重复使用手术器械),制造商必须准备并维护上市后监督报告(MDR第85条),该报告必须根据要求提供给主管部门。

对于IIa类、IIb类和III类器械,制造商必须为每个器械以及相关的每个类别或组别准备定期安全更新报告(MDR第86条)。对于IIb类和III类器械,该报告必须至少每年更新一次,对于IIa类器械,必须至少每两年更新一次。

2.5 可追溯性

对于III类植入性器械,经济运营商和医疗机构有义务记录其供应或接收的器械的UDI(MDR第27条)。

对于II类和III类器械,经济运营商在注册器械时有义务提供器械在或将在哪些成员国可获得的信息(附录VI A部分2.4)。对于植入性和III类器械,经济运营商必须提供安全和临床性能总结(附录VI A部分2.14)。对于单独包装和标签的一次性I类和IIa类器械,UDI载体不必出现在包装上,但必须出现在更高级别的包装上(附录VI C部分4.3)。

然而,如果医疗机构无法获得更高级别的包装,则UDI载体必须出现在单个器械包装上。

2.6 使用说明

通常,使用说明必须随器械一起提供。作为例外,如果I类和IIa类器械无需使用说明即可安全使用,且附录I第23节未规定其他要求,则可以不提供使用说明。

3 如何进行分类

本节旨在介绍用于应用分类原则和规则的定义和术语。

3.1 基本术语和定义

与器械分类相关的定义在MDR第2条和附录VIII第I章中规定,但该法规还包含其他术语的解释。以下收集了与本指南相关的术语和定义。

3.1.1 特定医疗用途

特定医疗用途由制造商从MDR第2(1)条列出的用途中指定。

3.1.2 使用时间

短暂性：通常用于连续使用不超过60分钟。 短期：通常用于连续使用60分钟至30天之间。 长期：通常用于连续使用超过30天。

在某些情况下,需要将产品的使用时间视为效果持续时间。例如,在皮肤上涂抹局部乳膏可能只需要几秒钟,但乳膏可能会在原位停留多个小时。因此,使用时间不应被视为涂抹产品所需的时间,而应是产品在体内或体表停留的时间。

3.1.3 连续使用

在计算MDR附录VIII第I章第1节所述的持续时间时,连续使用是指：

“(a) 同一器械的整个使用时间,不考虑在程序中暂时中断使用或为清洁或消毒器械而暂时移除。使用中断或器械移除是否为暂时性,应根据中断或移除前后的使用时间来确定；以及

(b) 制造商预期立即用同类型器械替换的器械的累计使用时间。”

例如,手术刀可能在整个手术过程中用于同一患者,手术可能持续数小时。但用于预期目的(即切割组织)的不间断使用通常每次只持续几秒钟。因此手术刀是短暂使用器械。然而,当器械的使用被中断是为了立即用相同或相同类型的器械替换时(例如更换输尿管导管),这应被视为器械连续使用的延续。

另一个例子是,在夜间清洁和消毒隐形眼镜的时间被视为器械使用的中断。在确定使用时间时,只需要考虑镜片不间断佩戴的指定时间段(例如16小时)。

如果无法证明器械的组件在使用间隔期间完全停止使用,这也被视为立即替换和器械连续使用的延续。

3.1.4 侵入性

侵入性器械： 任何完全或部分通过体表或体腔开口进入人体的器械。如果器械只向人体传递能量而器械本身不进入人体,则不应被视为侵入性器械。

体腔开口： 任何自然的身体开口,以及眼球外表面,或任何永久性人工开口,如造口。

受损的皮肤或粘膜： 由于病理改变或疾病、创伤或疤痕而发生改变的皮肤或粘膜区域。

手术侵入性器械： 通过体表(包括通过体腔开口的粘膜)在手术操作的帮助下或在手术操作环境中进入体内的侵入性器械；以及通过非体腔开口方式产生穿透的器械。

本定义中使用的手术操作一词包括所有通过体表将器械置入体内的临床介入程序。手术侵入性器械总是意味着它通过人工创建的开口进入。这可以是大开口,如手术切口,也可以是针头造成的针刺开口。因此,手术手套和注射器用针都是手术侵入性器械。

在这种情况下,应注意以下几点：

• 用于尿路造口、结肠造口和回肠造口或永久性气管造口的外科造口被视为体腔开口；因此,通过此类造口引入的器械不是手术侵入性器械。
• 相反,为接触循环系统而外科创建的开口不应被视为体腔开口。通过此类开口引入的器械是手术侵入性器械。

如果通过外科创建的开口与器官、组织或身体其他部位进行侵入性接触的液体,也应理解为手术侵入性的概念。

对于给药器械,此类物质必须单独评估(例如,通过喷射注射器给药的物质)。

可重复使用手术器械： 用于手术切割、钻孔、锯切、刮削、刮擦、夹持、牵开、夹夹或类似程序的器械,不与有源器械连接,且制造商预期在进行适当的清洁、消毒和灭菌等程序后可重复使用。

植入性器械： 任何预期：

• 完全引入人体内,或
• 通过临床干预替代上皮表面或眼球表面, 并在手术后保持原位的器械,包括那些部分或完全被吸收的器械。

任何通过临床干预部分引入人体并预期在手术后保持原位至少30天的器械也应被视为植入性器械。

在这种情况下,”手术”必须理解为包括植入物放置入体内的手术程序和与该程序相关的直接术后护理。”手术”不延伸到治疗结束,例如,取出植入物必须被视为另一次”手术”。因此,用于固定骨折的钢板在手术后保持原位至少30天是植入物,即使在骨折愈合后将其取出。在这种情况下,放置钢板和取出钢板是两个不同的手术程序。

有时部分植入的器械被视为植入物。例如,如果专门进行手术以放置输液港并在手术后保持原位至少30天,这样的输液港就是植入物。然而,用于临时血管通路且预期在7-10天内移除的非隧道中心静脉导管不是植入性器械。同样,用于皮肤伤口闭合且预期在30天前取出的缝线也不被视为植入物。

重要解剖位置： 就MDR而言,”中央循环系统 “指以下血管： 肺动脉、升主动脉、主动脉弓、降主动脉至主动脉分叉、冠状动脉、颈总动脉、颈外动脉、颈内动脉、大脑动脉、头臂干、心脏静脉、肺静脉、上腔静脉和下腔静脉。

就MDR而言,”中枢神经系统 “指大脑、脑膜和脊髓。

3.1.5 有源医疗器械

有源器械 指其运行依赖于非人体为该目的产生的能量源或重力的任何器械,其通过改变能量密度或转换该能量来发挥作用。在有源器械和患者之间传输能量、物质或其他元素而不发生任何显著变化的器械不应被视为有源器械。

通过转换能量 的概念包括器械内的能量转换和/或器械与组织之间界面或组织内的能量转换。用于心电图或脑电图的电极通常不被视为有源器械,因为它们通常不通过能量转换起作用。

使用人体能量来操作器械不会使器械成为”有源”器械,除非该能量被储存在器械中以供后续释放。例如,由人体肌肉产生并施加于注射器活塞的能量(从而导致物质输送给患者)不会使该注射器成为有源器械。然而,如果药物输送系统依赖手动上弦来预加载弹簧,随后释放以输送物质,则包含该弹簧的器械是有源器械。另一个例子是弹性泵,其中人体能量储存在拉伸的弹性层中。

使用预储存气体和/或真空作为动力源的医疗器械 被视为有源器械,只要它们满足定义下的两个标准,例如麻醉机的气体混合器、带有预储存推进气体的气雾剂止痛喷雾和气动吸引泵。

仅用于释放储存热能的加热/冷却垫不是有源器械,因为它们不通过能量转换起作用。然而,通过化学作用(例如放热或吸热反应)工作的加热/冷却垫是有源器械,因为它们将化学能转换为热能和/或反之。

显著变化 的概念包括能量性质、水平和密度的变化(参见规则9)。这意味着例如,电极在这个分类系统下不被视为有源器械,只要能量输入与能量输出相同。导线中导致输入和输出之间微小变化的电阻不能被视为”显著变化”。然而,用于切割组织或电凝的电外科电极是有源器械,因为它们的运行依赖于发生器提供的能量,其作用是通过器械与组织之间界面或组织中的能量转换实现的。

软件 也是有源器械。软件不应仅在规则11的背景下进行审查。

有源治疗器械 指单独使用或与其他器械组合使用的任何有源器械,用于支持、修改、替代或恢复生物功能或结构,以治疗或缓解疾病、损伤或残疾。

用于诊断和监测的有源器械 指单独使用或与其他器械组合使用的任何有源器械,用于提供信息以检测、诊断、监测或治疗生理状况、健康状态、疾病或先天性畸形。当器械本身提供疾病或状况的诊断,或提供决定性的诊断信息时,被认为允许直接诊断。

3.1.6 具有测量功能的器械

以下标准如果同时满足,表明器械具有测量功能：

a) 制造商预期该器械用于测量：

• 生理或解剖参数的定量值,或
• 输送到人体或从人体移除的能量或物质(包括药品)的数量或可量化特征。与药品共同包装并用于测量要给予患者的该药品数量的勺子或塑料注射器属于此类。用于向人体输送液体但没有刻度或刻度尺(例如无刻度或刻度尺或测量单位显示的药用勺、杯、滴管)的器械不属于此类。

b) 测量结果：

• 以法定单位或指令80/181/ECC20含义内的其他可接受单位显示,或
• 与以上述指令规定的法定单位或其他可接受单位表示的至少一个参考点进行比较。

c) 预期用途暗示明确或隐含的准确性,如果不符合隐含的准确性可能导致患者健康和安全的重大不良影响。

隐含声称 这一表述涵盖了这样的情况：用户基于器械的名称或其随附文件,或基于通常使用,有权期望准确性,而测量的准确性会影响患者的诊断或治疗。

制造过程中的测量活动,包括用于校准目的的活动,不包括在内,也不意味着制造的器械具有测量功能。

3.1.7 系统和手术包

系统和手术包在MDR第22条中有描述。它们可以组合医疗器械、体外诊断医疗器械和符合适用于这些产品的法规的其他产品,但前提是这些产品仅在医疗程序中使用或其在系统或手术包中的存在是合理的。在每个组件都证明具有法律合规性的情况下,系统或手术包本身不需要额外的CE标志,但必须标明组合产品的人的名称、注册商标或注册商号以及可联系到该人的地址。

手术包 是指为特定医疗目的而一起包装并投放市场的产品组合。系统 是指为实现特定医疗目的而预期互连或组合的产品组合,这些产品可以一起包装,也可以不一起包装。

如果系统或手术包包含未加贴CE标志的器械,或者所选择的器械组合就其原始预期用途而言不兼容,或者灭菌未按照制造商的说明进行,则该系统或手术包应被视为一个独立的器械,并应根据MDR第52条进行相关符合性评估程序。分类由系统或手术包的预期用途决定。组合器械的自然人或法人必须承担制造商的义务。

对于包括不同器械的此类组合,分类通常由预期用途决定。在最终器械的预期用途不足以确定分类的情况下,器械的分类应考虑新的预期用途,取决于所包含的最高分类器械的级别。

3.1.8 其他术语

本节说明MDR附录VIII中使用的其他术语：

系统性吸收 ：物质或其代谢物进入体内(例如,通过粘膜)并通过血液和/或淋巴系统分布到体内的过程。

完全或主要被吸收 ：”吸收”一词在植入性器械的背景下指材料在体内的降解以及通过体内代谢清除降解产物。它不适用于未经改变从体内排出的物质,例如用于腹腔或腹腔镜和内窥镜手术的充气气体。

局部扩散 ：物质保持在特定部位而不通过血液和/或淋巴系统分布到体内的状态。

药物/药品 ：根据指令2001/83/EC给出的定义： “(a) 任何被描述为具有治疗或预防人类疾病特性的物质或物质组合；或 (b) 任何可用于或施用于人体的物质或物质组合,其目的是通过发挥药理学、免疫学或代谢作用来恢复、纠正或改变生理功能,或进行医学诊断。”

“纳米材料“指含有以非结合状态、聚集体或团聚体形式存在的颗粒的天然、偶然产生或人工制造的材料,其中按数量粒径分布计,50%或以上的颗粒在一个或多个外部尺寸上处于1-100纳米范围内；富勒烯、石墨烯片和单壁碳纳米管在一个或多个外部尺寸小于1纳米时也应被视为纳米材料,根据MDR第2(18)条。相关的”颗粒”、”团聚体”和”聚集体”定义也包含在MDR第2(19-21)条中。关于纳米材料和相关术语的定义来自欧盟委员会建议2011/696/EU。关于定义中使用的术语和概念的指导可以在欧盟委员会联合研究中心的报告中找到。

衍生物 指通过制造过程从人体或动物组织或细胞中提取的非细胞物质。在这种情况下,用于制造器械的最终物质不含任何细胞或组织。

3.2 分类规则的应用

在应用分类规则之前,制造商应首先根据其特定医疗用途确定相关产品是否属于MDR范围内的医疗器械、医疗器械配件(MDR第2条)、用于更换的医疗器械部件或组件(MDR第23(2)条)或附录XVI中列出的无医疗用途的器械。

决定器械类别的是器械的预期用途而不是意外使用。例如,如果用于开心手术的缝线整理器预期保持在患者体外以保持缝线的正确顺序,则不应被视为侵入性器械。同样,如果医疗专业人员或其他人以制造商未预期的方式使用器械,这不会改变器械用于符合性评估的类别。然而,如果器械的正常临床使用随着临床实践的发展而随时间改变,以致器械的预期用途和分类发生变化,制造商应对此进行处理,并对器械进行新预期用途的符合性评估。决定器械类别的是制造商为器械指定的预期用途,而不是分配给其他类似产品的类别。例如,两种具有相同成分的缝线可能具有不同的预期用途。

如果基于器械的预期用途,同时适用多个规则,或者在同一分类规则内适用多个子规则,则应适用导致更高分类的最严格规则和子规则。

关于分类规则的进一步说明,还应考虑以下列出的要素。

3.2.1 如何使用规则

制造商必须考虑所有规则以确定其器械的适当分类。导致最高分类的最严格规则和子规则决定类别。例如,完全可以想象一个不特定于有源器械的一般规则仍然适用于这样的器械。必须考虑预期用途和器械的所有特征。符合预期用途的特征或特征组合中属于最高类别的特征决定器械整体的类别。

除了MDR附录VIII中规定的分类规则外,制造商还必须考虑任何适用的法律文件,并考虑可能支持其器械分类的指导文件。

3.2.2 实际示例

一个简单的伤口引流系统通常有三个必须考虑的组件：套管、导管和收集单元。如果系统不带套管销售,则不需要考虑套管的分类。这里假设系统用于短期使用,即不间断预期使用时间超过60分钟但少于30天。此外假设收集的液体不打算重新输注到体内或重新处理以便最终重新输注,且器械不打算连接到动力抽吸系统。

预期用途规则类别	规则	分类
手术侵入性套管到达胸腔伤口部位以引流腔体	7	IIa
非侵入性导管将体液排向收集器	1	I
非侵入性收集器接收体液	1	I

这里的明确结论是,制造商可以选择将IIa类应用于整个器械,或者对套管和导管及收集器分别进行符合性评估程序。

3.3 解释问题的处理

认识到虽然现有规则将充分对大多数现有器械进行分类,但少数器械可能更难分类。

一旦需要公告机构参与,制造商与相关公告机构之间因适用附录VIII而产生的任何争议,可提交给制造商(或其授权代表)注册地所在成员国的主管部门作出决定。如果制造商在欧盟没有注册地且尚未指定授权代表,此事项应提交给附录IX第2.2节第二段(b)项最后一段所述授权代表注册地所在成员国的主管部门。如果相关公告机构设在制造商所在成员国以外的其他成员国,主管部门必须在咨询指定该公告机构的成员国主管部门后作出决定。制造商注册地所在成员国的主管部门应将其决定通知MDCG和委员会。该决定可根据要求提供。

在这个监管程序之外,主管部门可以在自愿的特别基础上将复杂的分类案例提交给MDCG的边界和分类工作组讨论。该工作组就分类达成的一致意见将发布在《边界和分类手册》中供参考。