5 minute read.
The risk to patients and cost to American medical device companies was addressed by the United States Food and Drug Administration. The FDA worked with industry experts to understand best-practices for effective and efficient design, adding Design Controls to recommended guidelines.
In 1997, these guidelines became the FDA Quality System Regulation (QSR), a law under theCode of Federal Regulations, Title 21, part 820 (21 CFR 820).
General Requirements 21CFR820.30 (a)
- In the United States, design controls are required for all manufacturers of class Class II and Class III medical devices, and a few Class I devices.
- Design Controls are not required when researching new ideas. Design Controls begin, and must be documented, when a company commits to developing a product.
- The distinction between research and development should be defined in each company’s Quality System.
- Create and follow a development plan.
- Describe all responsibilities, timelines, ways to find more information, and when and how to update the plan.
- Plans should be clear, easy to follow, and accurate by updating throughout the design project using a team-driven process. An effective plan could be followed by anyone, not just your team.
Design Input 21CFR820.30 (c)
- Inputs are what needs to be accomplished by a design. At a minimum, design inputs must include user needs and regulatory requirements. Some companies include business needs.
- User needs often ambiguous terms like “lightweight” or “easy to set up,” and are refined by a company into requirements that are unambiguous and able to be measured by a test, like “less than 0.75 lbs” or “able to be set up within 30 seconds by untrained users.”
- User needs include risk, which must be constantly reaccessed as a design progresses.
- Inputs are agreed upon, in writing, by people listed in your plan.
Design Output 21CFR820.30 (d)
- Outputs are design features that satisfy inputs, such as drawings of parts, software code, operating procedures, product labels, etc.
- Outputs are reviewed and agree upon, in writing, by people listed in your plan.
drawings, software, test methods, etc.
Design Review 21CFR820.30 (e)
- Reviews ensure plans are followed and updated using a team-driven process.
- Reviews shall have at least one person attending who does not have responsibility for the stage of your plan being reviewed.
- At the least, design reviews authorize the design inputs, and that outputs satisfy the inputs through verification and validation testing.
- Reviews are approved, in writing, by people listed in your plan.
- Verification compares outputs to Input requirements.
- Verification must be measurable. For example, if a user need is for a “light weight” product, and the requirement is under 0.75 lbs, a verification test would be weighing the product to ensure it’s under 0.75 lbs. If a requirement is “less than 9 cm long,” verification could be simply referencing part dimensions on the design output.
- Verification is reviewed and approved, in writing, by people listed in your plan.
Design Validation 21CFR820.30 (g)
- Validation ensures Inputs are met for output that must be sampled statistically rather than measured directly. For example, measuring a mass-produced chemical wouldn’t be practical, output can tested using samples and validating consistency through statistics.
- Validation also ensures user needs are met from the user’s perspective. For example, if an Input is that a package “must be opened within 30 seconds” the final design couldn’t be measured directly, it must rely on real-world people in a controlled test.
- Validation statistics must be true, which means that often post-market surveillance must measure results and compare them to assumptions used for design validation, updating validation statistical requirements such as the sample size.
- Validation must use production-units in actual or simulated conditions.Validation is reviewed and approved, in writing, by people listed in your plan.
Design Transfer 21CFR820.30 (h)
- Ensure that you can transfer a design to manufacturing without losing control of outputs that were verified and validated.
- Transfer is reviewed and agreed upon, in writing, by people listed in your plan.
- Changes to inputs, outputs, and verification or validation methods must be controlled ensure there aren’t unforeseen consequences, including for other products that may share design components.
- Changes are reviewed and agreed upon, in writing, by people listed in your plan.
Design History File 21CFR820.30 (j)
- A Design History File (DHF) is evidence that a product was developed according to a Plan, starting with user needs, and referencing all inputs, outputs, verification, validation, and transfer procedures.
- The DHF is maintained for the life of a product, including future improvements and risk reductions.
- I emphasize that a DHF should include “why” changes are made so that future teams learn from current teams. This has been critical in addressing device recalls and designing improvements.
- FDA Quality System (QS) Regulation / Medical Device Good Manufacturing Practices21 CFR 820, printed version
- 21 CFR 820, electronic version (e-CFR)
- FDA “Device Advice” FDA Division of Industry & Consumer Education (DICE) Includes phone numbers for conversations with real people.
- FDA Design Control Guidance for Medical Device ManufacturersFDA guidance on Design Controls (.pdf version)
- FDA presentation on Design Controls
- FDA Center for Devices and Radiological Health (CDRH) online training, “CDRH Learn” (use keywords)
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