Design validation ensures that devices conform to defined user needs and the intended use stated in the design input. I believe a diagnostic microscope has no risk on people therefore there is no need for clinical trial. An implantable bone plate is considered class III medical device meaning highly risk for patients so we must perform clinical trial as part of design validation. An antimicrobial suture will require clinical trial because we don’t know how the patient is going to react, also it is considered class II. Lastly, an ergonomic knee brace is a class I with little or no risk, so we do not need a clinical trial.