医疗器械分类规则 – Non-invasive devices

NON-INVASIVE DEVICES

4.1. Rule 1

All non-invasive devices are classified as class I, unless one of the rules set out hereinafter applies.

[Explains from the guidance MDCG 2021-24, General explanation of rules/practical/issues/examples]

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.

[Rule 1 devices Examples]

Class I: All non-invasive devices are classified as class I, unless one of the rules set out hereinafter applies.

[Class I Device examples]

– Devices intended in general for external patient support (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 gels

– Non-invasive electrodes (electrodes for EEG or ECG)

– Permanent magnets for removal of ocular debris

– Wheelchairs pushed by hand

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.

4.2. Rule 2

All non-invasive devices intended for channelling or storing blood, body liquids, cells or tissues, liquids or gases for the purpose of eventual infusion, administration or introduction into the body are classified as class IIa:

— if they may be connected to a class IIa, class IIb or class III active device; or

— if they are intended for use for channelling or storing blood or other body liquids or for storing organs, parts of organs or body cells and tissues, except for blood bags; blood bags are classified as class IIb.

In all other cases, such devices are classified as class I.

[Explains from the guidance MDCG 2021-24, General explanation of rules/practical/issues/examples]

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.

[Rule 2 devices Examples]

Class IIa: All non-invasive devices intended for channeling or storing blood, body liquids, cells or tissues, liquids or gases for the purpose of eventual infusion, administration or introduction into the body are classified as class IIa, device examples:

– if they may be connected to a class IIa, class IIb or class III active device; or if they are intended for use for channeling or storing blood or other body liquids or for storing organs, parts of organs or body cells and tissues

– Devices intended to be used as channels in active drug delivery systems, e.g. tubing intended for use with an infusion pump

– Devices used for channelling gases, e.g. antistatic tubing for anaesthesia, anaesthesia 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)

– 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)

Class 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

Class 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 medicines Empty syringes without needles

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.

4.3. Rule 3

All non-invasive devices intended for modifying the biological or chemical composition of human tissues or cells, blood, other body liquids or other liquids intended for implantation or administration into the body are classified as class IIb, unless the treatment for which the device is used consists of filtration, centrifugation or exchanges of gas, heat, in which case they are classified as class IIa.

All non-invasive devices consisting of a substance or a mixture of substances intended to be used in vitro in direct contact with human cells, tissues or organs taken from the human body or used in vitro with human embryos before their implantation or administration into the body are classified as class III.

[Explains from the guidance MDCG 2021-24, General explanation of rules/practical/issues/examples]

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.

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.

[Rule 3 devices Examples]

Class IIb: All non-invasive devices intended for modifying the biological or chemical composition of human tissues or cells, blood, other body liquids or other liquids intended for implantation or administration into the body are classified as class IIb,

– Devices intended to remove undesirable substances out of the blood by exchange of solutes such as hemodialysers

– Devices intended to separate cells by physical means, e.g. gradient medium for sperm separation

– Haemodialysis concentrates

– Device removing specific blood cells (e.g. activated) by specific binding to a matrix

Class IIa: unless the treatment for which the device is used consists of filtration, centrifugation or exchanges of gas, heat, in which case they are classified as class IIa – Particulate filtration of blood in an extracorporeal circulation system. These are used to remove particles from the blood,

– Centrifugation of blood to prepare it for transfusion or autotransfusion excluding centrifuges for manufacturing a medicinal product

– Removal of carbon dioxide from the blood and/or adding oxygen

– Warming or cooling the blood in an extracorporeal circulation system.

Class III: All non-invasive devices consisting of a substance or a mixture of substances intended to be used in vitro in direct contact with human cells, tissues or organs taken from the human body or used in vitro with human embryos before their implantation or administration into the body are classified as class III.

– Substances or mixture of substances for transport, perfusion, storage of organs intended for transplantation that do not achieve the principal intended action by pharmacological,

immunological or metabolic means

– IVF or ART products without principal pharmacological/metabolic action (substances or mixture of substances)

– IVF cell media without human albumin

These devices are normally used in conjunction with an active medical device covered under Rule 9 or Rule 11.

Filtration and centrifugation should be understood in the context of this rule as being done exclusively through mechanical methods.

4.4. Rule 4

All non-invasive devices which come into contact with injured skin or mucous membrane are classified as:

— class I if they are intended to be used as a mechanical barrier, for compression or for absorption of exudates;

— class IIb if they are intended to be used principally for injuries to skin which have breached the dermis or mucous membrane and can only heal by secondary intent;

— class IIa if they are principally intended to manage the micro-environment of injured skin or mucous membrane; and

— class IIa in all other cases.

This rule applies also to the invasive devices that come into contact with injured mucous membrane.

[Explains from the guidance MDCG 2021-24, General explanation of rules/practical/issues/examples]

Rule 4 – Devices that come into contact with injured skin or mucous membrane

This rule applies to non-invasive devices as well as invasive devices that come into contact with injured skin or mucous membrane.

This rule is intended to primarily cover wound dressings independently of the depth of the skin wound or mucosa wound. The conventional types of products, such as those used as a mechanical barrier, are well understood and do not result in any great hazard. There have also been rapid technological developments in this area, with the emergence of new types of wound dressings for which new types of claims are made, e.g. management of the microenvironment of a wound to enhance its natural healing mechanism.

More novel claims relate to the mechanism of healing by secondary intent, such as influencing the underlying mechanisms of granulation or epithelial formation or preventing contraction of the wound. Some devices used on breached dermis or breached mucosa may even have a life-sustaining or lifesaving purpose, e.g. when there is full thickness destruction of the skin or mucosa over a large area and/or systemic impact.

Dressings incorporating a substance which, if used separately, can be considered to be a medicinal product and that has an action ancillary to that of the dressing, fall within class III under Rule 14. Devices composed of other substances which are absorbed by or locally dispersed in the human body fall under Rule 21.

[Rule 4 devices Examples]

Class I:  All non-invasive devices which come into contact with injured skin or mucous membrane are classified as:

– class I if they are intended to be used as a mechanical barrier, for compression or for absorption of exudates;  – Wound dressings for skin or mucous, such as: absorbent pads, island dressings, cotton wool, wound strips, adhesive bandages (sticking plasters, band-aid) and gauze dressings which act as a barrier, maintain wound position or absorb exudates from the wound

– Ostomy bags

Class IIb:

– class IIb if they are intended to be used principally for injuries to skin which have breached the dermis or mucous membrane and can only heal by secondary intent;   Are principally intended to be used with severe wounds:

– Dressings intended for ulcerated wounds having breached the dermis

– Dressings intended for burns having breached the dermis

– Dressings for severe decubitus wounds

– Dressings incorporating means of augmenting tissue and providing a temporary skin substitute

Class IIa:

– class IIa if they are principally intended to manage the micro-environment of injured skin or mucous membrane; and

– Hydrogel dressings for wounds or injuries that have not breached the dermis or can only heal by secondary intent

– Non-medicated impregnated gauze dressings

– Polymer film dressings

Class IIa:

– class IIa in all other cases

Class I:  This rule applies also to the invasive devices that come into contact with injured mucous membrane.

– Dressings for nose bleeds (the purpose of the dressing is not to manage micro-environment) are in class I according to this rule

– Dental wound dressings not containing animal derived material

The classification of devices covered by this rule depends on the use intended by the manufacturer’s, e.g. a polymeric film dressing would be in class IIa if the intended use is to manage the micro-environment of the wound or in class I if its intended use is limited to retaining an invasive cannula at the wound site. Consequently, it is impossible to say a priori that a particular type of dressing belongs to a given class without knowing its intended use as defined by the manufacturer. However, a claim that the device is interactive or active with respect to the wound healing process usually implies that the device is at least class IIa.

Most dressings that are intended for a use that falls under class IIa or IIb also perform functions that are in class I, e.g. that of a mechanical barrier. Such devices are nevertheless classified according to their intended use in the higher class.

For such devices incorporating a substance which, if used separately, can be considered to be medicinal product or a human blood derivative, or animal tissues or derivatives rendered non-viable, see Rule 14 or Rule 18 respectively.

Explanation of special concepts:

Breached dermis or mucosa: the wound exposes at least partly the subcutaneous tissue.

Secondary intent: the wound heals by first being filled with granulation tissue; subsequently the epithelium grows back over the granulation tissue and the wound contracts. In contrast, primary intent implies that the edges of the wound are close enough or pulled together, e.g. by suturing, to allow the wound to heal before formation of granulation tissue.