Evaluation of vibrotactile guidance for motion and language communication
Creators: name: Andreyka, Elizabeth O.
Publisher: name: The University of Texas at Austin
Year: 2023
Subjects: Haptics
Teleoperation
Guidance sleeve
Braille

description: This thesis presents experiments on a vibrotactile guidance sleeve used for two different applications: 2D trajectory following with motion based guidance and communication for applications in surgical training settings, and a refreshable Braille device for language based communication. Our 2D trajectory following experiment was designed with training for percutaneous needle insertion in mind. Percutaneous needle insertion is a vital task for trauma surgeons to learn, and often requires years of training and practice to master. With tightening restrictions on resident work hours, getting this experience has become challenging; the need to expedite gaining expertise in trauma procedures is urgent. We present an experiment for near online 2D telementoring trajectory following comparing the efficacy of haptic guidance from a vibrotactile sleeve to verbal guidance in communicating movement cues. Our experiment was double blind with participants either receiving haptic or verbal guidance cues, and involved a mentor (experimenter) and trainee (participant). For each trial, the mentor followed a predetermined 2D path, and the trainee received movement guidance cues, haptic or verbal, to follow the mentor based on the mentor’s position. The predetermined paths either had stepwise, diagonal, or curved elements. Success was determined for each trial by the root mean squared error between the mentor and the trainee, and final trajectory correlation between the mentor and the trainee. The results show that the participants receiving haptic feedback performed significantly better in terms of both average error and trajectory correlation. Both haptic and verbal participants did significantly worse on stepwise paths than diagonal or curved paths; there was no significant difference in performance between haptic and verbal participants for stepwise paths. For diagonal and curved paths, haptic participants performed significantly better in terms of average error and trajectory correlation than verbal participants. For the visually impaired, in an increasingly digital world, access to written information has become more difficult. Because of this, research has focused on making refreshable Braille displays cost friendly and effective for linguistic communication and learning. In this study, we created two Braille displays: one designed in a previous study using solenoids, and the other a novel cost-friendly vibrotactile sleeve with six vibration motors. Participants were tasked with single letter Braille reading comprehension receiving guidance from the two devices compared to a standard Braille training board. To assess the effectiveness of each method, the time it took each participant to guess a letter (comprehension time) and accuracy of the guess were recorded. The comprehension time using the solenoid device was 43% faster than the traditional Braille print, and the vibrotactile sleeve was 11% faster than the traditional Braille print. Both the solenoid and vibration actuator devices resulted in 79.5% accuracy for the Braille readings, compared to 75% for the standard Braille print. Overall, these two studies emphasize the potential use of haptic guidance for communication of desired motion or language cues.