Wearable lip-based electrotactile display : feasibility study, modeling, and system design

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] For assisting visually impaired to effectively perceive critical spatial information through the sense of touch, we proposed a wearable lip-based electrotactile display. The miniaturized display is most effective with lip interface due to the excellent sensory characteristics of lips. Since lips have never been utilized for tactile display applications, two human- subject experiments (6M/2F) including threshold measurement and two-line separation rating, have been designed to investigate the electrotactile sensitivity and spatial discriminating abilities of lips. Experimental results indicate excellent sensory characteristics suitable for electrotactile applications. Finite Element Modeling is applied to study the Activating Function (AF) and the Current Density (CD) distribution within superficial lip tissue. This computational method could help reveal the working principles behind electro stimulation. Furthermore, simulation results of 5 proposed geometrical electrode designs demonstrate the optimization of the AF and the CD for more uniform distribution. Finally, LTSPICE is used to simulate the performance of a designed on-chip waveform generator at the schematic level. This functional building block will be integrated with a wireless communication module in the near future, which will extend the living space of the blind by offering promising features of high portability and wearability.