What are some must have technical accessories

BlogRegulatory AffairsMedical Device Accessories: Definition and Regulatory Requirements

Medical device accessories: definition and regulatory requirements

What many understand by accessories differs from the definition of the term in the Medical Devices Act.

This article gives you an overview of the definition of the term, the regulatory requirements and typical questions.

1. Definition of the term accessories

a) Accessories according to MPG or MDD

The Medical Devices Act defines the term as follows:

"Accessories for medical products are objects, substances and preparations made from substances that are not themselves medical products according to number 1, but are intended by the manufacturer to be used with a medical product so that it can be used in accordance with the intended purpose of the medical product specified by the manufacturer. "

b) Accessories according to MDR

The Medical Device Regulation MDR defines the term almost word for word:


"An object that is not a medical device per se, but is intended by the manufacturer to be used together with one or more specific medical devices, and which specifically enables its use in accordance with its intended purpose (s) or with which the medical The function of the medical device or medical devices with regard to their intended purpose (s) is to be supported directly and in a targeted manner; "

Examples of accessories are foot switches and remote controls for operating tables, cleaning agents, tools for installing, calibrating and maintaining medical products, as well as special brackets and covers.

You can read below how accessories and spare parts are differentiated.

c) Accessories according to FDA

For the FDA is a medical device

"An instrument, apparatus, implement, machine, contrivance, implant, in vitro reagent, or other similar or related article, including a component part, or accessory which is:

  • [...] intended for use in the diagnosis of disease or other conditions, or in the cure, mitigation, treatment, or prevention of disease, in man or other animals, or
  • intended to affect the structure or any function of the body of man or other animals, and which does not achieve its primary intended purposes through chemical action within or on the body of man or other animals and which is not dependent upon being metabolized for the achievement of any of its primary intended purposes. "

It is therefore clear that an accessory is also a medical product (“device”) and that the relevant regulations apply. The FDA also explicitly defines the term accessories:

The term "support" is to be understood in several ways:

  1. Necessary requirement
    The medical device cannot be used without the accessories, i.e. the accessories are a prerequisite for their use.
  2. Not necessary requirement
    The medical device can also be used without accessories, e.g. an infusion pump (medical device), which can also be used without the associated stand (accessories).
  3. Expansion of functionality
    The accessories extend the functionality but not the intended purpose of the medical device. For example, a pulse oximeter (accessory) can expand the functionality of a monitor (it can now also display the oxygen saturation), but not its intended use (display and record physiological parameters).
  4. Improvement of the functionality
    Finally, accessories can improve the function of a medical device. For example, by adding colors or contrast filters, software can improve the performance of a product that delivers the raw images.

The examples come from the FDA Guidance Document " Medical Device Accessories - Describing Accessories and Classification Pathways ".

2. Regulatory requirements

a) MPG

The Medical Devices Act applies equally to medical devices and their accessories. "Accessories are treated as an independent medical product", writes the MPG.

This means that manufacturers of accessories have to prove all basic requirements for accessories and go through a conformity assessment procedure for them.

b) MDR

The MDR demands with regard to accessories:

  • The manufacturers must list the intended accessories in the technical documentation
  • and taken into account in clinical evaluation.
  • The instructions for use must explain how to use the accessories.

Just like the MDD, the MDR also insists that manufacturers meet the basic safety and performance requirements and demonstrate that they are in the context of a conformity assessment procedure. As with any medical device.

b) FDA


The FDA sees it similarly:

"The FDA has a long-standing rule which says that anything intended to be used as an accessory to a medical device is itself a medical device and regulated to the same level as the device it accessorizes."

FDA guidance document (see below)

The FDA permits the approval of accessories both together with the "parent device" and via a separate approval process.

"A finished device whose performance is supported, supplemented, and / or augmented by one or more accessories."
Source: FDA guidance document (see below)

It may well be that an accessory has to go through a Premarket Approval (PMA), Premarket Notification (PMN, 510 (k)) or a de-novo procedure.


According to the above quotation, the FDA basically classifies accessories in the same class of so-called “parent devices”, unless the risks for the accessories are different from those for the main product / parent device. The accessories are then classified independently according to these risks.

Another reason for a different classification is if the accessories are to be used for many “parent devices”.

More on this in the Guidance Document " Medical Device Accessories - Describing Accessories and Classification Pathways ".

3. Can software be an accessory to a medical device?

a) Europe

Question: Is an independent one (stand-alone) software to calibrate a medical device itself a medical device? Or an accessory for a medical device? Or neither?

This simple-sounding question is not that easy to answer. To do this, we have to delve into the history of the term definitions.

Deviating from the current definition, the MPG defined the term in the first edition in 1994 as follows:

equipment for medical devices are objects, substances, preparations made from substances and software that are not themselves medical devices according to number 1, but are intended by the manufacturer to [...] "


With the amendment of the MDD in 2007, the definition of the medical device was expanded to make it clearer that software can also be a medical device. This can be found in the reason for the change. The implementation in the MPG in 2009 adopted this definition in full and also adjusted the definition of accessories in the same amendment by deleting “software” there. However, this should not mean that software can no longer be an accessory.

Conclusion: The problem arises from the adoption of the definition of accessories in the MPG and is a misinterpretation of the changes from 2009.

In the MDR it says in the recitals:

"The classification of the software either as a product or as an accessory is independent of the location of the software and of the type of connection between the software and a product."

Recital (19) MDR

b) USA / FDA

In the guidance document on accessories mentioned above, the FDA explicitly emphasizes that standalone software ("Software as a Medical Device" SaMD) can also be an accessory, but does not have to be: If the software is to be used for medical purposes without hardware, this is Software itself is a medical product and not an accessory.

4. Same manufacturer for medical device and accessories

Question: Does the manufacturer of the accessories have to be the same who places the associated medical device on the market? Asked otherwise, should the following definition of accessories have to be supplemented by the words in brackets?

"Accessories for medical devices are objects, substances and preparations made from substances that are not themselves medical devices according to number 1, but are intended by the manufacturer (of the accessories) to be used with a medical device (the" main product ") so that this (" Main product ") can be used according to the intended purpose of the medical device (" main product ") specified by him (the manufacturer of the accessories)."

Answer: no. It cannot be assumed that it is meant in such a way that it must be about the identical manufacturer. This can also be seen in the "reality" that these are often different manufacturers. For dialysis machines, for example, the blood tubing market is a competitive one.

By the way: This is exactly why, for example, many manufacturers design their devices in such a way that the manufacturers of suitable accessories, especially consumables, have a hard time and users have to buy the "original accessories".

5. Accessories versus spare parts

Question: What does it look like when you sell a roller pump for a dialysis machine? Is that now an accessory or a spare part?

  1. It could be a equipment because, by definition, an accessory is an object that is intended by the manufacturer to be used with a medical device so that it can be used in accordance with the intended purpose of the medical device as defined by the manufacturer. And a roller pump is used to ensure that the dialysis machine can be used for its intended purpose.
  2. It could also be a Spare part because a defective roller pump in the dialysis machine has to be replaced.

The first answer to the question is: It doesn't have to be an either or. Products can be both spare parts and accessories. Let's look at this in a specific case:

If you do not sell the roller pump on your own, but only offer it as a spare part, then it is a spare part. This means that you do not have to subject the roller pump to your own conformity assessment procedure. Rather, you check the conformity of the entire dialysis system including the roller pump.

If, on the other hand, you place the roller pump on the market as an optional product, you will need a conformity test. It is then an accessory. The fact that this can be exchanged as a spare part does not change anything.

It depends on your type of communication and declaration whether a scooter pump can only be classified as a spare part or also as an accessory.

5. Risk management for accessories

Risk management for an accessory cannot be carried out in ignorance of the medical device with which it is to be used together.

Risk management should also not repeat the elements of risk management for the product, but rather add the elements resulting from the specific use and construction of the accessory. Therefore, the FMEA is a helpful method for risk analysis for the accessories.

Categories: Regulatory Affairs
Tags: Basic Requirements | General safety and performance requirements, conformity assessment procedures for medical devices, medical software