Improving haptic experience through biomechanical measurements

Haptic interfaces have been used as a surrogate for many real world applications such as rehabilitation, calligraphy, design and surgical training. While development of haptically enabled systems are opening new avenues in training, very few studies have explored if they provide realistic and matching muscle activations compared to real world activities. In this paper a novel methodology based on muscle activity is proposed for evaluation of haptic systems. To test this methodology experiments were performed on a haptic writing simulator and comparisons were made to corresponding real pen and paper task. The behavior of two muscles, flexor carpi ulnaris and extensor digitorum communis was studied with the help of surface EMG´s, during the execution of similar real and haptic based tasks. Human participant studies were carried out and results indicate that in the majority of parameters studied, the haptics based writing simulator used in this study resulted in muscle exertion and excitation similar to that of pen and paper tasks. It was seen that the proposed methodology could be used to tune the haptic system to mimic real life writing more closely. This study showed that the proposed methodology can lead to improved haptic simulators by studying the bio-mechanical reaction in humans.