Every medical device carries a short statement of what it is for. It is easy to treat it as a line of marketing text, written near the end. It is not. The class, the risk analysis, the regulatory route and the labelling all depend on it. A statement written loosely at the start gives a plan that has to be rebuilt later.
What the regulations mean by intended use
India and the EU define it in similar terms. The Medical Devices Rules, 2017 in India define the intended use as the use for which the device is intended, according to the data the manufacturer supplies on the labelling, in the instructions for use or in promotional material, as approved by the Central Licensing Authority. The EU Medical Device Regulation 2017/745 uses the term intended purpose in Article 2(12), with the same sources: the label, the instructions, promotional or sales material and statements, and the clinical evaluation.
In the US, 21 CFR 801.4 refers to the objective intent of the persons legally responsible for the labelling. That intent can be shown by their expressions, by the design or composition of the device, and by the circumstances of its distribution: for example labelling claims, advertising, and oral or written statements. So in the US the intended use can reach beyond the words on the label. In the EU and the US, what you say about the device, wherever you say it, is part of the evidence.
Intended use and indications for use
The US FDA separates two terms that are often mixed up. In its 2014 guidance on the 510(k) program, the intended use is the general purpose or function of the device. The indications for use, as defined in 21 CFR 814.20(b)(3)(i), describe the disease or condition the device will diagnose, treat, prevent, cure or mitigate, including the patient population for which it is intended. The intended use includes the indications.
A device with a general, tool-like indication has the same indications for use and intended use. The guidance gives a scalpel indicated for cutting tissue as an example. A scalpel indicated for removing one type of cancerous cell has specific indications. For a 510(k), the indications of the new device must fall within the intended use of the predicate device.
What a good statement contains
The EU requirements for the instructions for use (Annex I, section 23.4) and for the technical documentation (Annex II, section 1.1) list the particulars that go with the intended purpose. They make a useful checklist:
| Part | The question it answers |
|---|---|
| Intended purpose | What does the device do: diagnose, treat or monitor? |
| Medical condition | Which disease, injury or condition is it for? |
| Patient population | On whom: adults, children, a defined group of patients? |
| Intended users | Who operates it: a specialist, a nurse, the patient at home? |
| Indications and contra-indications | When should it be used, and when should it not be used? |
Annex II asks separately for the principle of operation, which describes how the device achieves its purpose. Keep it beside the statement, not inside it. For classification, add the facts the rules test: which part of the body the device touches, whether it is invasive, and for how long it is in contact. Write each part as a plain statement of fact. A reader should be able to check each one against the design and the evidence.
Compare two statements for the same imaginary nebuliser. The first says: "A device that delivers medicine." It names a function and nothing else. The second says: "A nebuliser intended to turn a prescribed liquid medicine into an aerosol for inhalation, for the treatment of asthma in adults, used by patients at home." It names the purpose, the condition, the patients, the users and the route into the body. Each of those words can now be tested, and each one tells the designer what the device must do. The example is for illustration only; it is not a statement for any real device.
What the statement drives
- The class. The First Schedule of the Indian Rules says the classification provisions are governed by the intended purpose of the device. The EU MDR says the same in Annex VIII. If several rules apply, the stricter rule and the higher class apply.
- The most critical use. Under the Indian Rules, a device not intended for use solely or mainly in one part of the body is classified on its most critical specified use. The EU MDR has the same rule in Annex VIII.
- The risk analysis. The EU MDR asks the manufacturer to estimate and evaluate the risks during the intended use and during reasonably foreseeable misuse (Annex I, section 3).
- The route in the US. The FDA can find a device substantially equivalent to a predicate only if the two have the same intended use.
- The claims. Article 7 of the EU MDR prohibits labelling or advertising that suggests uses other than those in the intended purpose for which conformity was assessed.
Common mistakes
- Writing it last. By then the design, the tests and the class have been planned against a guess.
- Making it broad to keep options open. A wider claim can mean a higher class and more evidence. Claim what you can support now. A new indication added later can amount to a new intended use, and it can need a new submission or a new conformity assessment.
- Letting sales material drift. Promotional material is one of the sources of the intended use in all three systems. A new claim in a brochure or on a website is a new claim.
- Describing the technology instead of the use. "Makes an aerosol with a compressor" says how. It does not say for whom, for what condition or by which user.
- Keeping different versions. The label, the instructions, the risk file and the application should carry the same words.
When to write it
Write the statement at the start of the design, as the first design input, and put it under document control. Check it again at every design review that touches the users, the patients or the claim. Treat any change to it as a design change, and assess its effect on the class, the risk file and the evidence before you make it.
Sources: Medical Devices Rules, 2017, rule 3(v) and the First Schedule (CDSCO); Regulation (EU) 2017/745, Article 2(12), Article 7, Annex I sections 3 and 23.4, Annex II section 1.1 and Annex VIII Chapter II (EUR-Lex); 21 CFR 801.4; US FDA guidance, The 510(k) Program: Evaluating Substantial Equivalence in Premarket Notifications, 28 July 2014. This article is a general guide, not a regulatory determination for any device.