Medical device design verification

Design input is the most important element in the development of a successful medical device. Design input forms the basis of all development activities, it is also the standard for which all verification and validation activities are based. Unfortunately, organizations often short-cut this part of the project because they... 

Validation in quality systems includes establishment of procedures on how to qualify the equipment and machinery, how to verify the design of products, how to verify the process designed, how to verify the achievement of production procedures, how to validate the process developed, and how to validate the methods for measurement and assay. Validation also requires verification of specifications or acceptance criteria of in-process parameters relating to both raw materials and intermediate (in-process product) and finished products, and verification of acceptance criteria for in-process parameters relating to operating conditions of machinery and equipment. Further, when the medical device is assembled at the user s site, validation includes establishing procedures of how to verify assembly. 

For medical devices, there is a phenomenon recognized as feature creep , in which the specifications for the design features of a device begin to drift toward a specification limit because inadequate design reviews, output verification and change control. This same sort of variability occurs with... 

To be able to certify that software can be commercialized because it is safe and fulfils its mission for public health, an inspector needs to know what the software does, that it works properly and that it does not imply risks. Validation of safety is a broad concept for medical devices in software speak it means the assurance that the process of software design, construction and verification is planned and controlled. 

Every requirement in the DIR must be verified even if the requirement is carried over from a previous device. Whenever possible, perform step stress testing to failure, this is used to ensure there is adequate design margin in the device. This discussion addresses primarily the final medical device. However, the expeeta-tion is that similar verification activities will also be carried out for all critical subsystem and custom component specifications. 

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