Development of medical devices

21 November 2018, Updated 13 February 2019

Medical devices are products which are used to diagnose, prevent relieve or treat a disease, disability, injury, etc. There are more than 500,000 different types of medical devices available, covering anything from wheelchairs and glasses to pacemakers, mobile phone apps and state-of-the-art surgical equipment.

Click on the steps below to read about the phases that medical devices must go through before and after marketing.

An idea about a new medical device begins to form. The idea could come from a doctor, a nurse, a researcher, a medical device company or a citizen who has come up with a good idea. The first step is to determine if the idea can be realised. This would typically involve working with engineers and other experts. If the idea is viable, the device must then be prototyped – usually in collaboration with a medical device company financing the development of the medical device.

Before a medical device can be used for patients, it must work as intended and be safe to use. Right from the start, the manufacturer must perform tests to document the performance and safety of the device and show that the benefits of using it outweigh any potential risks. For the sake of patient safety, implanted devices and devices in risk class III must be subjected to clinical investigation, including where appropriate testing in humans.

These investigations are included in a risk analysis and a clinical evaluation, which are key elements of the manufacturer's technical documentation to certify the performance and safety of the device. Besides the manufacturer's own tests and clinical data, the documentation could also include knowledge from scientific articles. The documentation of the device must be updated regularly.

If the manufacturer can demonstrate to the notified body that the product is equivalent to an already marketed product, and the manufacturer is able to present documentation of the safety and performance of the equivalent product, then the manufacturer does not have to conduct all the investigations all over before marketing of the product. This is called equivalence.

Early in the development phase, the manufacturer must determine which of the four risk classes the device belongs to. Class I represents the lowest risk, e.g. patches and wheelchairs, whereas class III represents the highest risk, e.g. pacemakers and knee prostheses.

The risk class depends on factors such as for how long and how often the device is to be used, and whether the device is to be implanted in patients. Please see the triangle with the four risk classes. (danish only)

If the device developed by the manufacturer belongs to class I, the manufacturer is responsible for monitoring the efficacy and safety of the device. If the device belongs to the medium- to high-risk classes (IIa, IIb and III), the technical documentation of the device must be reviewed and assessed by external experts in a so-called notified body, which is a private organisation authorised by the Danish Medicines Agency.

Medical devices must be CE marked before they can be placed on the market. CE marking shows that the device complies with EU legislation. If a medical device is in a higher risk class than class I, then a so-called notified body must assess if the device can be CE marked. The notified body assesses if the documentation for the product's safety and performance is sufficient for the product to be CE marked. Once this declaration has been signed, the manufacturer may affix the CE marking to its device and begin marketing the product.

When the device is available on the market, the manufacturer must continue to monitor the device.

In addition, healthcare professionals, manufacturers, distributors and importers of medical devices have a duty to report it to the Danish Medicines Agency if a device results in an accident or incident regardless of whether the cause is a device malfunction or misuse. Citizens can also submit reports.

The Danish Medicines Agency receives all reports. Against this basis, we are able to assess if measures are required, including, in the extreme, if the product should be withdrawn from the market, if the instructions for use should be changed or if we need to instruct the manufacturer to alter the device.

The Danish Medicines Agency's reporting system is part of the European monitoring collaboration.

Medical devices belonging to class II and III must be recertified regularly. This means that the documentation of the device must be reviewed by experts in the notified bodies at regular intervals. The review of the documentation must take place at least every five years to ensure the device is still safe to use and works as intended.

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