The main device testing is carried out in the Gait Laboraty (click here). is equipped with the Vicon motion capture system that has capability of monitoring human movement and ground reaction forces. This is achieved by using a system of cameras to track reflective markers attached to the human body. The system calculates the position of an object in 3D space, gives a reference from with the accuracy of our system can be determined.
A pressure mapping system ultilised a matrix of resistive sensors to measure force. This allows understanding of the pressure distribution over the base of the foot and measurement of forces exerted. The pressure distribution can be interpreted as an analytical meansure of relative comfort of the devices installed in the sole of the boot. As one of our intentions is to minize the changes felt in the foot by the users.
In addition, force analysis were carried out with subjects performing a range of activities such as standing, walking, brisk walking, jogging and jumping. The error in each results was carefully calibrated using the assumption that forces only exerts on the foot during contact with the ground.
The data showed that the greatest force of 3100N was experience when a 70kg individual landed on one hell from a standing jump. This is equivalent to 4.5 times the body weight. This knowledge is later ultilised when designing the housing for electronic components.
The delicate electronic components are house in the heel of the boot, as this was proven from last year to provide a reliable tracking location, providing impact and environmental protection. Various simulations were carried out on Solid Works with different designs material. This is to ensure the housing can provide a solid protection for the components from impact and other factors.
In our current prototype, a lid with pillars, which was designed to withstand a force of 3100N as mentioned above, was manufactured using rapid prototype. This is then later slotted into a milled enclosure to provide a compact yet strong housing.
For our next prototype, it is proposed that a horseshoe shape design can be a viable solution. This is due to most of the force is mainly distributed in the center of the heel, as found out from using TekScan.