Quantifying Prosthesis Control Improvements Using a Vibrotactile Representation of Grip Force

Prosthetic technology is a prime candidate for the integration of haptic feedback. Conventional myoelectric prostheses do not have a mechanism to convey any sensory information, making it difficult for users to feel connected to their hand and to engage in active grasping and exploration tasks. Vibrotactile stimulation is a simple and safe choice for a noninvasive haptic display that can be easily integrated into current hardware. A force-matching grasping task is used to quantify performance improvements at three different force levels with a pulsing vibrotactile feedback channel to convey grasping force. Results show that the haptic feedback led to improved performance in an experienced subgroup of subjects while naive subjects showed no improvement. These preliminary findings suggest that users experienced in EMG control may be able to improve their control of grasping capabilities with a vibrotactile representation of grip force.