Drawing the Line: Wearable Linear Haptics Motivated by Guided Breathing.

Haptic wearables provide an intuitive human-machine interface to convey information through the sense of touch, which may have promising applications in guided breathing. In this paper, we detail the design and evaluation of three wearable prototypes (Vibration, Skin Drag, and Tapping) capable of administering discrete (individual, separate pulses and stimuli) and continuous (overlapping or uninterrupted stimuli) forms of linear haptic cycles with inspiration from slow, deep guided breathing. Characterization was performed to quantify and validate the performance of six haptic stimuli (discrete/continuous vibration, skin drag, and tapping). Devices were quantified with key metrics that described the applied stimuli and the dynamics of the wearable. A human subjects study (N=25), composed of two-cycle tracking tasks, was conducted to determine device performance and user aptitude. Results indicated consistent directional recognition across all six stimuli, but discrete stimuli performed better in spatial localization tasks. Although outperformed in tracking/localization tasks, continuous stimuli, especially skin drag, were described as the most apt and intuitive pairing to guided breathing. Findings highlight the potential of these linear haptic stimuli in a number of applications, including guided breathing, navigation, virtual immersion, and communication.