We lean toward declaring the objective unacceptable, but the real answer begins with "It depends." (In fact, for any observable objective, the answer begins with "It depends.")
"Design" is clearly an observable action, so the objective passes that criterion. The problem is with the "clear" criterion. Designing a biomedical device could be anything from a five-minute activity to a Ph.D. dissertation to an industrial project that takes a large team years to accomplish. We think that to be useful, the objective should be more explicit about the scope of the required design.
On the other hand, if the instructor went over several designs of approximately the same scope in class and provided practice in several more, the students should have a good idea of what the objective calls on them to do. In that case, the objective would be both observable and clear, and so would be acceptable. If you chose this response ("acceptable"), no problem--just understand why we voted the other way and the conditions under which your response would be correct.
Try Objective 6.