Vyas et al., HapToes: Vibrotactile Numeric Information Delivery, IEEE Haptics Symposium 2020

Hello I am Preeti Vyas, in this video I will be discussing HapToes a method for vibrotactile numeric information delivery. Conveying haptic numeric information can be beneficial for a lot of applications when use of eyes or ears are not possible. For example, wearable navigation devices, control room environment, and fitness and health monitoring system Single haptic actuator can be a convenient and efficient mechanism for rendering such information. However, single-actuator based temporal rendering can be restrictive due to actuator and human perception constraints. It is also easily disrupted by secondary task.

00:47 - Prior research shows that our mental number line is spatially associated; hence we hypothesize that conveying numeric information on a spatial haptic display would be more effective. Fingers might be a good candidate for such display, but our fingers are often occupied in day-to-day interactions. We thought of leveraging the toes as a 10-unit tactile display, which we have already demonstrated through our perception study. In that study, we designed an encoding to better differentiate the tactile stimuli on toes. While testing that design, 88% of errors arrived due to the confusion between the adjacent toes. So, we improved the encoding.

01:37 - In our updated rendering, for toe 1, we stimulated only the target toe, the same idea applied to toes 3, 5, 6, 8, and 10. For toe 2, we stimulated the closest edge toe followed by the target toe; the same idea applied to toes 4,7 and 9. We ran a study and conveyed single and three values using ActiVibe, a previously discussed haptic numeric rendering, and Haptoes, our haptic encoding on toes. We chose Activibe, as a benchmark to evaluate the performance of our method. Both the conditions were tested in conjunction with an audio distractor task.

02:31 - We compared the two conditions using metrics of accuracy and time response. Overall, the results show that HapToes performed at par with Activibe for conveying single-value, and significantly better for conveying three-values. As the bottom line, we can use toes to convey numeric information under distraction. Please read our paper for more details. Thank you .