Identification of Vibrotactile Patterns Encoding Obstacle Distance Information

Abstract

Delivering distance information of nearby obstacles from sensors embedded in a white cane-in addition to the intrinsic mechanical feedback from the cane-can aid the visually impaired in ambulating independently. Haptics is a common modality for conveying such information to cane users, typically in the form of vibrotactile signals. In this context, we investigated the effect of tactile rendering methods, tactile feedback configurations and directions of tactile flow on the identification of obstacle distance. Three tactile rendering methods with temporal variation only, spatio-temporal variation and spatial/temporal/intensity variation were investigated for two vibration feedback configurations. Results showed a significant interaction between tactile rendering method and feedback configuration. Spatio-temporal variation generally resulted in high correct identification rates for both feedback configurations. In the case of the four-finger vibration, tactile rendering with spatial/temporal/intensity variation also resulted in high distance identification rate. Further, participants expressed their preference for the four-finger vibration over the single-finger vibration in a survey. Both preferred rendering methods with spatio-temporal variation and spatial/temporal/intensity variation for the four-finger vibration could convey obstacle distance information with low workload. Overall, the presented findings provide valuable insights and guidance for the design of haptic displays for electronic travel aids for the visually impaired.

Testing a Shape-Changing Haptic Navigation Device With Vision-Impaired and Sighted Audiences in an Immersive Theater Setting

“…Despite continuing investigation in this area (e.g. [38], [41]) few commercial solutions have resulted to practically benefit VI individuals. Indeed, the most successful application of vibrotactile feedback has been in providing discrete notifications in cell phones.…”

Obstacle Detection Display for Visually Impaired: Coding of Direction, Distance, and Height on a Vibrotactile Waist Band

“…Vibration intensity was used to provide distance cues. Shah et al (2006), Bouzit et al (2004), Kim et al (2015), and Amemiya and Sugiyama (2009) also used the hands as display location. These hand-mounted displays can successfully support blind users to safely walk along a predefined route at their usual walking pace but also have several inherent disadvantages: the hands are not ego-referenced and information presentation may also interfere with other tasks, including simply holding objects and using the white cane (Pawluk et al, 2015).…”

Vibrotactile Display of Flight Attitude with Combination of Multiple Coding Parameters

“…The coding strategies for these vibrotactile displays have so far been rather basic [19]. An intuitive and well-perceivable coding method can reduce training time and increase user acceptance of a tactile device.…”