Design Verification and Design Validation (DV&V for short) are integral to the medical device New Product Development (NPD) process. After a brief introduction of relevant concepts, we'll provide an overview of Design Verification and Design Validation using three methods: in a longer technical explanation, a brief technical statement and finally, a brief non-technical (but memorable) sentence.
Introduction: Intended Use, User Needs, Design Inputs and Design Output
Intended Use(s) and User Needs
Among the first activities in NPD is to establish the intended use(s) of the device and the user needs. To do this we can make use of feedback from the following sources:
• Patients (surveys, reviews, etc.)
• Clinicians (conferences, literature, complaints, etc.)
• Marketing (customer surveys)
• Research & Development (benchmarking, competitive intelligence, reverse engineering, etc.)
• Sales (customer feedback)
• Regulatory (assessments, reviews, etc.)
The intended use(s) and user needs are then translated to engineering language – that is, quantitative requirements that can be objectively measured. Examples of these types of requirements are:
• Interface / mating
• Packaging & Transportation
• Labeling and IFU
• Cleaning & Sterility
• Legal & Regulatory
Since the requirements above will serve as the basis for the device design, they are called design inputs. One of the most important conditions for design inputs is they must be complete, unambiguous, and not conflict with each other. Design inputs may not meet these conditions upon initial formulation, and a thorough review of the design inputs is performed – both by the project team as well as independent reviewer(s) from outside the team*.
*It is found in practice that independent reviewers are quick to spot potentially incomplete, ambiguous, or conflicting requirements more easily and frequently than project team members.
Based on the previous information, the device is then designed, defined, and documented. These design specifications can be:
• Material specifications
• Packaging specifications
• Part / assembly drawings
• Bill of materials
• Routers (travelers)
• Labeling specifications
• Process specifications
The collection of procedures and specifications for a finished device is the Device Master Record (DMR). The device, its packaging and labeling, and the DMR then comprise the entirety of the design output.
Once the device has been designed, we must verify that the quantitative requirements that were originally developed have been fulfilled. Design Verification is therefore defined as confirmation by examination and provision of objective evidence that the design output meets the design input requirements. This includes interface to other equipment if so designed.
Design verification protocols are documented and approved that contain the methods, acceptance criteria and sample size rationale (statistical, as appropriate) for the various verification activities. Reports are then created and approved that document the outcome of the verification activities.
Design Verification confirms that the design output meets the design input requirements.
In Design Verification we ask: did we build the product right?
In Design Validation, the objective is to ensure the product satisfies the intended use and needs of the user and patient. It includes testing using initial production units or their equivalents under actual or simulated use conditions. Clinical evaluations, performance evaluations, literature reviews and predicate device comparisons are examples of design validation activities. Software validation and interface with other devices (if included in the intended use) may also be performed, as applicable.
Just like in design verification, design validation protocols are documented and approved that contain the methods, acceptance criteria and sample size rationale (statistical, as appropriate) for the validation activities. Reports are created and approved documenting the outcome.
Design Validation is completed before release for use of the product to customers.
Design Validation confirms that the product meets the user requirements and intended use(s)
In Design Validation we ask: did we build the right product?