Performance Testing Summary

Performance testing consisted of a series of three tests designed to determine how the prototype could withstand use. The purpose of this session was to better understand the physical limitations of our device and to determine if these limitations jeopardize our final prototype’s functionality. This appendix explains the methodology used to conduct testing and summarizes the results of performance testing.

Methodology

Performance testing was conducted at the Ford Design Center. The prototype was first placed under a team member’s feet while they pulled up on the top straps to safely simulate the device bearing a person’s weight. Next, one team member held the device steady while another pulled on the handle from varying directions to test the strength of the loops. Finally, the rubber handles of the device were squeezed to determine the strength of the adhesive used to bind them together.

Belt strength test

• The device did not break from any amount of force exerted on the yoga belt

• The device did not appear to be under strain in any particular area

• The device did not stretch from the force which it was under

Handle Stability Test

• The loops did not break under strain

• The handle which was not fully sealed to loops rotated freely while being pulled

• The handle which had been sealed to its loop did not rotate around loop

  • The loop twisted with the handle’s rotation

• The loops did not become stretched out from the strain they were under

Handle Compressibility Test

• The handle experienced mild splitting when compressed along the axis on which it was cut (See figure 1)

  • Splitting was minor and easily repaired

  • Splitting did not cause device to fail but could lead to that if the splitting accumulates

• The handle did not break or split when compressed along other axes

Performance testing provided important information about how our final prototype is able to withstand strain associated with its use. Following these tests, we have determined that our final prototype is able to withstand the normal amount of strain which it would endure when in use. The straps of the yoga belt were able to withstand a large amount of force without becoming misshapen or starting to break. This combined with success in user testing makes us confident that our device can easily withstand the weight of Marc’s leg. The rubber handles and loops of the yoga belt were able to withstand being pulled and twisted also without breaking or losing form. While splitting in the handle when being compressed is a concern, the small amount of splitting observed combined with the fact that the handle is not meant to be squeezed heavily but rather pulled make us confident that our device will function well for a relatively long time. Given the small window of time left to construct a prototype, other options of adhesives will not be extensively explored but rather noted as a future development.