Assessment of substitutive vibrotactile feedback for performing object manipulation task with prosthetics

In every day tasks, such as grabbing a cup, prosthetics users lack the sensory feedback needed to complete them successfully. This study assesses a non-invasive method of communicating the sensory feedback through vibration applied on a healthy body site. In order to do so, an experiment was developed including a game during which subjects had to drag a box to avoid incoming objects in a virtual environment by using a haptic device to move through the virtual space. Dragging involves proper force estimation upon the moveable box. Performance of the feedback method was quantified by the amount of times the exerted force broke the box, or the box crashed into incoming objects. It was found that vibrotactile feedback does not yield significant improvement in performance over merely visual feedback from the object’s compliance. Training effects were observed.