Prosthetic Arm Force Reducer Team 1 – Halliday's ... - Ohio University

5.1.4 Concept D – Upgraded Springs for the Otto Bock Hook
Once the similarities between our concept and the existing Otto Bock hook were noted, the team
was fairly adamant about sourcing an Otto Bock hook rather than fabricate our own design. The
Otto Bock hook incorporates four springs total – two springs on either side of the hook with one
spring encompassing the other on either side of the hook (see Figure 5.1.3). In order to increase
the grip force of this hook, more rugged springs could be incorporated. Figure 5.1.6 shows what
the Otto Bock hook might look like with a stronger spring incorporated on one side of the hook.
Figure 5.1.6 – Otto Bock hook with Upgraded Spring
5.2 Concept Development, Scoring and Selection
Table 5.2.1 (as seen on the next page) was used in order to select which of the four concepts
should be pursued. It was decided by the team that our resources could be allocated effectively
to develop 2-3 of the concepts that were discussed. Two sets of criteria were used in determining
the best concepts – “user needs” and “producer” criteria. Various aspects of these categories
were the broken down and rated with what we deemed an “importance factor.” Each concept
was then objectively rated in each of these areas and the value given to each concept was
multiplied by the importance factor. In order to determine the best concepts all that had to be
done was sum the total ratings of each individual concept. Ultimately the decision was made to
progress with the two highest rated concepts.
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