Week 9: Prototyping

This week, we finally put together a prototype of the Orthoglove. So far, we attached one FSR to the thumb and connected the four other fingers to the servo. Although this model does not yet have cables linking the fingers on the underside, it has the ability to pull the fingers open (figure 10).

Figure 10: The servo/cable control

An earlier program was used to control the servo. Instead of staying at rest under no FSR pressure, the servo is instructed to return to its zero position. This also required us to use a servo that is not modified for continuous rotation. Since such a conventional servo has less travel, the cables system had to be shortened considerably to allow the fingers to open completely with an under 180 degree servo rotation. The cables used were also switched to thread for this prototype due to difficulty with the fishing line. However, the final prototype of the Orthoglove will likely use fishing line.

During an early test, the Orthoglove appeared to help with hand flexion, successfully assisting in dropping an object after gripping (figure 11). However, it is difficult to tell how well the design works since it was tested on our own hands with no impairment. 

Figure 11: Early testing of the Orthoglove with an FSR on the thumb