Page 326 - Flexible Robotics in Medicine

316 Chapter 13

Figure 13.32
Mechanical analysis of Prototype 7.0.

device. Further analysis of the prototypes after failure revealed that the point of
weakness within the flexible tip was at the neck of the main conduit segment.
However, even though there was breakage, the connector segments served to contain
the fragments; this was another fail-safe should the flexible tip of the device fail under
unexpectedly high stress.

In conclusion, the mechanical analysis of nylon as well as Prototypes 5.0 7.0 show yield
stresses, which are far higher than the mathematically and theoretically defined limit of
49.7 MPa. This proves the robustness of the design and shows that the final design,
Prototype 7.0, is the sturdiest of them all, with a yield stress of around eight times greater
than what the stepper motors can deliver.

13.7 Design review, specification, and benchmarking

In addition to design verification, the design review process involves several other
aspects. This section covers the necessary steps for the evaluation of the design. For the
scope of user specification, it is required to define the user needs with its
corresponding matrices, establish the target specifications, and specify the design
acceptance criteria.