Insole Testing for Mechanical Durability and Accuracy
GoX Studio Insole Testing for Mechanical Durability and Accuracy
GRF estimate from GoX Studio Insole vs. Instrumented Treadmill in Gate Lab, November 2018
Mechanical Stability: Output signal comparison at 0 vs. 500,000 cycles, October 2018
A preliminary algorithm for generating GRF values from the insole sensors has been developed for walking at 0.9m/s. The algorithm filters the data, combines signals, and applies an equation to generate peak GRF forces that fall within 4% of the actual values. Table 1 shows GRF values generated by the algorithm compared to actual GRF values recorded from the Gait Lab treadmill, Chart 1 shows a graph of the GRF values generated from GoX Insole and Chart 2 is the same step data recorded by the treadmill.
Table 1: Insole GRF vs Treadmill GRF
Chart 1: GoX Insole GRF
Chart 2: Treadmill GRF
Fatigue testing on GoX insole was completed for 500,000 steps. The results show that the insole design is robust enough to handle the 500,000 steps with only slight changes in signal response. Table 2 shows the actuated/non-actuated values for the insole at key points during the test, and a brief analysis of the data and Chart 3 shows the insole response at the key points overlaid.
Table 2: 500k Fatigue Testing Results
Chart 3: 500k Fatigue Testing Results
Results show that after a break-in period, which occurs quickly, the insole maintains a steady response, only deviating by 4.47% after 500,000 steps. Even looking at the insole response before break-in, the response changes by 25.61%, which may seem high however the insole can lose up to 50% of its range before the signals produced become unusable.