Mid-Air Tactile Stimulation for Pain Distraction

Using the human sense of touch, pain control has been studied for decades. With the rise of Virtual Reality (VR) and haptic technologies, creating VR and haptic sensations provide a unique opportunity for pain distraction. In this paper, we present an experimental study to test whether VR and mid-air ultrasound tactile stimulation reduce perceived pain simulated via the cold pressor test, i.e., submerging a human hand in cold water (2 degrees C) for as long as the test subject can. Fifty right-handed subjects participated in the study and three tasks were considered: task 1 involved experiencing the cold pressor test with no distraction (considered as the control task), task 2 involved playing a simple VR game with no tactile feedback, and task 3 utilized the same VR game with tactile feedback; tasks 2 and 3 were assigned in random order after task 1. The tolerance time, perceived pain rating, and quality of experience were evaluated and compared for the three tasks. Results demonstrated that when a VR task involves physical (touch) interaction, tactile stimulation plays a significant role in increasing pain tolerance time. Furthermore, the study demonstrated that for high pain tolerance participants, tactile stimulation is more effective for pain distraction compared to low pain tolerance participants. Although there are no significant differences in perceived pain and quality of experience between VR and VR+Tactile tasks, there are significant differences in tolerance time (Wilcox signed rank test, p < 0.05). It is presumed that VR and the tactile stimulation induces positive emotions when utilized (for both valence and arousal).