Figure 3: Finger angles (Left) and corresponding angle calculations (Right)
Before we began our design, we reviewed a few research papers that helped us understand finger kinematics. One paper we reviewed created a simplified model of the finger using a triangular shape to find the general maximum angles and angle ratios that can be used to simulate finger movement (Kim, 2008). This can be seen in figure 3. The corresponding formulas used are seen after. Figure 3: Angles in the fingerto the right.
Another research paper we reviewed gave general length ratios of each phalanx taking the distal as 1.0, medial as 1.5, and proximal as 2.4 (Buryanov, 2010). This allowed us to better understand the length ratios and angle ratios that need to be met in the design to achieve a relatively natural finger movement of the prosthetic.
Utilizing these two pieces of information a Matlab program was developed to simulate natural finger movement. After successfully simulating natural finger movement, models of the M-Finger and X-Finger were then developed to observe their movements. All code can be seen in the appendix. Finally, a model of the prototype prosthetic was then developed for use in the final prototyping stage and for further research development. GIFs of the Matlab models are seen below.
Figure 4: Matlab Simulations