Capacitive Touch Sensitive Vibro-Haptic Typing Training System for the Visually Impaired

Introduction

There are certain mechanical tasks that humans do to on a regular basis. These tasks are generally (but not mandatorily) repetitive in nature, and the more often these tasks are performed, our brain tries to store some of the muscular/mental procedures in a special way (by creating multiple neural connections to the same destination), so that they are accessed faster, and thus requiring lesser and lesser amount of active involvement of the brain, therefore developing the “muscle memory” (Zukin & Snyder, 1984). The concept of Passive Haptic Learning is when an external haptic stimulus is provided to the user in order to accentuate the learning process. These tasks could vary from riding/balancing a bicycle, driving, playing any musical instrument, or as in this case, learning to type on a “qwerty” keyboard, (Coon, 2005) and (Zukin & Snyder, 1984).

The proposed system utilizes the above philosophy and implements a PHL (Passive Haptic Learning) based training system for the visually impaired. This system encourages the user to use natural movements, and learn to type without the need for “seeing” the actual keys, as the visual inputs are substituted and routed through other mechanisms such as haptic and audio cues. This learning system can be thought of the supporting wheels on a bicycle, which are attached while a child learns to ride, in order to prevent him from falling. However unknowingly soon enough the child learns to naturally balance the bicycle and once the wheels are removed, he realizes that he has learnt the art of balancing the bicycle and thus, doesn’t fall. This is the kind of implicit learning and skill development that is aimed by virtue of this device (Zukin & Snyder, 1984).

The proposed system is the final outcome of many design considerations such as camera (Kinect) based implementation, which was highly costly. The glove device is a product of multiple iterations. Detailed feedbacks were collected on the regular basis from users, based on the level of comfort, long term usage, level of invasiveness, and any impact on the natural movement of the hand. The objective was to create the least invasive design, in the lightest possible form factor. The current system is lightweight fingerless glove which is effective and economical solution for quick PHL typing training for the visually impaired. Also, being connected to the mobile application, the system can adapt to the skill level of the user and thus is able to adapt and optimize its level of difficulty/dexterity.