Products from software to autos are subject to strict quality assurance processes, as well as design verification and validation. Products produced for a highly regulated market must meet stringent requirements and provide documentation of their quality assurance processes, as well as the steps they have taken to verify and validate their designs.
Nowhere is this more essential than in the area of healthcare products. Safety and efficacy are the two top reasons why you need to verify and validate medical device design. Verification and validation are two different but equally essential processes.
The Difference Between Verification and Validation
When designing a new medical device, teams need to answer two critical questions:
Did we design the device right? – this is the verification of the design.
Did we design the right device? – this is the validation of the device.
The Specifics of Verification
Verification is an internal process designed to determine if the design inputs match the design outputs. In other words, does the design comply with requirements, applicable regulations, specifications, and conditions set forth in the design plans and assembly instructions?
Verification is typically a theoretical process. It’s an examination of the design to determine if all relevant inputs have been considered and addressed in the design, and that the output of the design, the built product, will meet specifications.
The Food and Drug Administration (FDA) defines verification as “confirmation by examination and provision of objective evidence that specified requirements have been fulfilled.” To conduct design verification, development teams must determine what the device must do, and how it will do it.
Designs will specify things like speed, volume, weight, portability, or output. Drawings or computer-assisted designs are inspected and analyzed during verification by developing tests that demonstrate that the design addresses each of the specifications and that the built device will be able to meet each of the defined specifications and expected outcomes.
Verification not only demonstrates that the product will do what it’s supposed to do, but that it does it in the way the design anticipates. The process must account for each design input and corresponding output. Tests of each function and the system as a whole are documented, and the system should be analyzed and inspected to identify any flaws in the design that could impact the proper operation of the device. These tests, analyses, and inspections answer the question, “did we build (or design) the device right?”
If verification identifies problems with the design that may cause the device to fail to perform as expected, design revisions will be developed and tested until verification determines that the design will result in a device that will work properly for its intended purpose.
Verification may be performed on each component of a proposed design, and then on how the assembled components will meet design specifications when working together.
Validation Is an External Process
Validation differs from verification in that validation focuses on whether the device meets user needs in real-world settings. The FDA defines validation as “establishing by objective evidence that the device specifications conform with user needs and intended use(s).” This is the answer to the question, “Did we build the right device?”
Whereas verification may be conducted entirely on the design, validation involves testing the built device in a real-world setting with the intended users. The most important consideration is whether the device meets user needs.
No device design team wants to discover during validation that the device fails to meet user needs. To avoid this expensive and time-consuming mistake, teams must create design controls at the outset of the development process that guide the capture of user needs and trace the connections between those needs and design inputs, outputs, verification, and validation.
The design process also incorporates risk management and quality assurance. The end result, in the form of the built device, must be proven both safe and effective. Having specific written controls that address risks and define quality assurance practices is necessary.
The international standards organization now incorporates documentation requirements that include detailed traceability, along with information about verification, validation, monitoring, measurement, inspection and testing, handling, storage, and distribution activities relating to the product, plus specific product acceptance criteria (ISO 13485:2016).
Creating a traceability matrix has become so integral to the verification and validation process that specialized software has been developed that can help teams create and update these matrices to keep track of how all the parts of a design, and the design inputs, are interrelated with external factors like portability, distribution, storage, and user needs.
Increasing Complexity Requires Diverse Teams
Medical device design has progressed rapidly in recent years. Miniaturization, integrated electronics and connectivity, and new methods of identifying pathogens and treating chronic diseases require that teams have a variety of expertise. Experts in different disciplines work together to produce devices that can pass verification and validation tests.
Mechanical engineering for diagnostic devices has become essential, as has expertise in materials, chemistry, software, and engineering for integrated chips, methods of prototyping, and experience in evaluating user experiences.
All members of the team should be involved from the earliest stages of conceptualizing a new medical device. This means that before the first design drawings are made, experts from various disciplines have met to discuss considerations from every angle, answering questions like, “What need are we attempting to address?” and “Are there existing devices that already attempt to meet that need?”
If other devices exist, the team must determine if there’s a better way to address the need than the method used in existing devices. Can they make a better device that’s less costly, or more comfortable, more portable, or more accurate?
Medical device design verification and validation are sometimes lumped together as “V and V.” But it’s important to understand the different goals of the verification and validation processes. Moreover, verification and validation may refer to the device design, but also may apply to design processes or associated software. Teams should be specific in their planning, to ensure that everyone understands just what’s being verified.
Once the design is verified and the device is built, validation yields important information about the user experience. If the design process incorporated information about user needs appropriately from the beginning, the device should meet user needs without surprises.