In-Home Haptic Feedback Training for Ankle Rehabilitation

Brian Battaglia, Mustafa Nassery, Alexander Brukson
supervised by Dr. Kristiina McConville, Associate Professor for the Department of Electrical and Computer Engineering

This system combines an accelerometer and pressure sensors coupled with a custom modified ankle brace; all of which are used to manipulate a game display on a home PC or laptop. The game will encourage individuals to perform certain movements which stimulate rehabilitation and recovery for injured ankles. Its simultaneously provides a level of entertainment to keep the participant involved. The game was programmed in Adobe Flash which will allow it to be easily modified for the use on a portable mobile application or a web-based game.

Ankle rehabilitation and physiotherapy is a long and lack luster process which may prolong the recovery time and even increases the risk of re-injury if not performed or done improperly. The design of the ankle brace rehabilitation system we propose will help to alleviate the tedious process of physiotherapy. The system we propose is divided into 3 game phases where the movements and tasks performed by the ankle increase in complexity and target a specific type of physiotherapy based exercise.

The first phase game uses the force sensors located on the bottom of the foot; applying pressure to the different parts of the foot will control the movements of the on-screen avatar. The goal of the game is to avoid incoming obstacles for as long as possible. In this phase, the core muscles related to the ankle are exercised without increasing the strain to the joint (also known as isometric exerices). Once a desired level of improvement is acheived the patient will be ready to move on to the second phase.

The game in the second phase involves matching a set of movements where a full range of motion in 4 possible directions is dealt with. The patient will move his ankle to the left, right, up, or down depending on the direction arrow shown in the screen. This phase works to stretch and exercise the muscles of the ankle to recover a full range of motion in the ankle. Once the full range of motion of the ankle is recovered the participant can proceed to the third stage.

The final phase of the rehabilitation system is to recover proprioception by incorporating a balancing game. The patient will have to balance on a wobble board and manipulate the game by tilting the board to different directions without tipping over. The game is based on avoidance requiring the avatar to move out of the way of the enemies while collecting objects to increase the players score. This phase will recover the nerve damage as well as muscle damage to the tissue involved in balance and coordination. This phase is the most crucial for reducing the risk of re-injury since the usual source of re-injury is the lack of proper balance and coordination in patients.

Project targeted applications: The most direct application of our game is to be used as a supplement, or possibly a replacement of the traditional physiotherapy upon further refinement of the gaming requirements. Another application for our brace design is for the tracking of gait in an individual. Since the accelerometer can be used to observe the orientation of the ankle, a healthcare professional would be able to determine any abnormalities in the gait of an individual such as drop foot (a result of some stroke patients). Similarly the pressure sensors attached at the bottom of the foot can be used to monitor the patient's weight distribution on the soles of the foot and determine if the weight bearing properties of the ankle are deteriorating.