Navigating Medical Device Development: A Hands-on Guide - Part 2 - Device Risk Classification
In my latest article, part of a series on Navigating Medical Device Development: A Hands-on Guide, we explored the journey from an initial idea for a device to its development as a medical device. In this article, we will provide a concise introduction to the ISO 13485 standard, the EU Medical Device Regulation (MDR), the device's intended use and purpose, and the medical device's risk classification.
Table of Contents
By now, you have implemented a Quality Management System (QMS) based on ISO 13485, incorporating additional procedures to meet the regulatory requirements of the Medical Device Regulation MDR and FDA CFR 21.
Also, you now have a better understanding of ISO 13485 (see Figure 1), particularly regarding Management responsibilities, Resource Management (including Infrastructure and Resources), Product Realization (covering Design, Development, and Production), and Measurement, Analysis, and Improvement. The entry point to your QMS is the Quality Manual. Here, you demonstrate which standards and regulations your QMS conforms to, how each chapter and section are connected to your procedures, and other contents such as the Quality Policy and Organizational Structure.
In ISO 13485, you have a set of requirements (what and when) that you need to fulfill with your QMS to develop a medical device. The QMS you set up for your company should include a set of procedures that outline (how and where) to fulfill those requirements, supported by flow charts. Additionally, you will have a set of templates under each procedure that you will actually complete (where) during the product development process.
For each product or product family, you need to have a separate place for keeping all the documents and records specific to that particular product. In ISO 13485, these files are called Design and Development Files (DDF). On the other hand, in FDA CFR, these files are referred to as Design History Files (DHF) (see Figure 2).
Intended purpose/use
Great! But what is the next step? Where to go from here? You pondered in your mind. After thoroughly reviewing your QMS procedures, regulations, and some guidelines, you finally understood that the next step is to formally write the intended use/purpose of the device. But wait, what exactly is that? After referring to the MDR, you found the definition for the intended purpose as...
‘intended purpose’ means the use for which a device is intended according to the data supplied by the manufacturer on the label, in the instructions for use or in promotional or sales materials or statements and as specified by the manufacturer in the clinical evaluation;
What should I put on the label of the device? Hm... after very deep thoughts, you came up with the intended use as:
A throat examining device designed for diagnosing infections.
Congratulations! Now you have an intended purpose, and you can check if the device you will be developing falls under that medical device category. This process is known as qualifying as a medical device. The definition for a medical device under MDR is:
‘medical device’ means any instrument, apparatus, appliance, software, implant, reagent, material or other article intended by the manufacturer to be used, alone or in combination, for human beings for one or more of the following specific medical purposes:
— diagnosis, prevention, monitoring, prediction, prognosis, treatment or alleviation of disease,
— diagnosis, monitoring, treatment, alleviation of, or compensation for, an injury or disability,
— investigation, replacement or modification of the anatomy or of a physiological or pathological process or state,
— providing information by means of in vitro examination of specimens derived from the human body, including organ, blood and tissue donations, and which does not achieve its principal intended action by pharmacological, immunological or metabolic means, in or on the human body, but which may be assisted in its function by such means.
The following products shall also be deemed to be medical devices:
— devices for the control or support of conception;
— products specifically intended for the cleaning, disinfection or sterilisation of devices as referred to in Article 1(4) and of those referred to in the first paragraph of this point.?
According to the above definition, especially:
— diagnosis, prevention, monitoring, prediction, prognosis, treatment or alleviation of disease.
Your device is qualified as a medical device. Congratulations! Now that you have an intended purpose and your device is qualified as a medical device, you can proceed to identify the risk class of the device.
Risk classification
A risk class refers to the classification of a medical device based on a risk-based system, considering factors such as the vulnerability of the human body and the potential risks associated with the device. In this system, medical devices are categorized into different risk classes, and as the risk class increases, the requirements for legal compliance also become more stringent. The classification helps determine the level of scrutiny and regulatory requirements that a specific medical device must meet to ensure its safety and efficacy for use.
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Risk classes
By now, you are familiar with the main classifications under MDR Article 51, and they are (see Figure 3):
Also, you have come to understand that some Class I devices can be further subdivided according to MDR Article 52(7)(a), (b), and (c) as:
Also, you understood that for Class I devices, there is no need for the involvement of a notified body in the conformity assessment process. However, for Class I subdivisions, the involvement of a Notified Body is required in assessing specific requirements. For example, for Class Is, a notified body must assess the Sterile conditions.
For other higher classes, a full involvement of a notified body is required. But what is a Notified Body? Fortunately, you found the definition in Chapter 1, Article 2 of the MDR as:
‘notified body’ means a conformity assessment body designated in accordance with this Regulation;
Risk classification rules
Now, you enter into the classification of your Throat diagnosing device. You have already learned that you have to check the 22 classification rules set out in ANNEX VIII of MDR. If your answer to one of the rules is Yes, then your device belongs to that class. If you have more than one rule with a Yes answer, then the strictest rule and sub-rule resulting in the higher classification shall apply.
You found a template in your QMS corresponding to those rules, and you started filling them out. However, you came across a few more new terms in the rules from MDR, and you started to understand their meanings. Some of the terms are:
Now you are equipped with much more information and ready to start the classification. You filled the answers as Yes/No starting from Rule 1 as follows (for simplicity, rules are not shown):
Only Rule 5 is applicable and that is
Rule 5: All invasive devices with respect to body orifices, other than surgically invasive devices, which are not intended for connection to an active device or which are intended for connection to a class I active device are classified as:
— class I if they are intended for transient use;
— class IIa if they are intended for short-term use, except if they are used in the oral cavity as far as the pharynx, in an ear canal up to the ear drum or in the nasal cavity, in which case they are classified as class I; and?
Your reasoning is: The throat diagnosing device is an invasive medical device used through the oral cavity as far as the pharynx (without touching the pharynx), so it is a Class I medical device according to the classification rules.
Congratulations on classifying your medical device as Class I according to MDR! Now, let's check if your device belongs to any of the Class Is, Class Im, or Class Ir sub-divisions, which would require partial involvement of the notified body.
For Class Is, Class Im, and Class Ir, additional specific requirements related to safety and performance are applied. These requirements are detailed in Annex VIII of MDR.
Since the device is used for examining the throat, it should operate under sterile conditions. While it may not be necessary to deliver it as a sterile device, the user must ensure that the device is sterile before each use. As a manufacturer, you must ensure that there is a proper sterilization procedure for your device, and it must be effective. The notified body will need to assess this sterilization procedure during the conformity assessment. Therefore, your medical device belongs to Class Is.
You decided to stick with Class Is for now and review it once you have more information available. This approach will allow you to proceed with the development process while keeping the option open to reevaluate the classification if new data or insights become available in the future.
Congratulations! You have reached the end of this article. I hope you enjoyed reading it, and I hope it has inspired you to learn more about medical device development. Curious to know the rest? especially the formal design and development, please see the next chapter.
If you have any questions or comments, please feel free to leave them below. I will be happy to answer them.
Thank you for reading!