Design of a Vibrotactile Vest for Contour Perception

A vibrotactile array is a promising human computer interface which could display graphical information to users in a tactile form. This paper presents the design and testing of an image contour display system with a vibrotactile array. The tactile image display system is attached to the back of the user. It converts visual graphics into 2D tactile images and allows subjects to feel the contours of objects through vibration stimulus. The system consists of a USB camera, 48 (6×8) vibrating motors and an embedded control system. The image is captured by the camera and the 2D contour is extracted and transformed into vibrotactile stimuli using a temporal-spatial dynamic coding method. Preliminary experiments were carried out and the optimal parameters of the vibrating time and duration were explored. To evaluate the feasibility and robustness of this vibration mode, letters were also tactilely displayed and the recognition rate about the alphabet letter display was investigated. It was shown that under the condition of no pre-training for the subjects, the recognition rate was 82%. Such a recognition rate is higher than that of the scanning mode (47.5%) and the improved handwriting mode (76.8%). The results indicated that the proposed method was efficient in conveying the contour information to the visually impaired by means of vibrations.

[1]  D. Caudrey,et al.  Tactile-Evoked Potentials in Schizophrenia , 1983, British Journal of Psychiatry.

[2]  Dong-Soo Kwon,et al.  Applications of a miniature pin-array tactile module for a mobile device , 2008, 2008 International Conference on Control, Automation and Systems.

[3]  Kyungkoo Jun,et al.  Touchable Video and Tactile Audio , 2009, 2009 11th IEEE International Symposium on Multimedia.

[4]  Carter C. Collins,et al.  Tactile Television - Mechanical and Electrical Image Projection , 1970 .

[5]  Mark A. Neerincx,et al.  Effects of mobile map orientation and tactile feedback on navigation speed and situation awareness , 2008, Mobile HCI.

[6]  Ryan M. Traylor,et al.  A Haptic Back Display for Attentional and Directional Cueing , 2003 .

[7]  John B. Morrell,et al.  Design and evaluation of a vibrotactile seat to improve spatial awareness while driving , 2010, 2010 IEEE Haptics Symposium.

[8]  Richard D. Gilson,et al.  Vibrotactile Guidance Cues for Target Acquisition , 2007, IEEE Transactions on Systems, Man, and Cybernetics, Part C (Applications and Reviews).

[9]  Gi-Hun Yang,et al.  T-hive : Vibrotactile interface presenting spatial information on handle surface , 2009, 2009 IEEE International Conference on Robotics and Automation.

[10]  Yuichiro Kume,et al.  Vibrotactile letter reading using a low-resolution tactor array , 2004, 12th International Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems, 2004. HAPTICS '04. Proceedings..

[11]  Deborah I. Fels,et al.  Vibrotactile Display of Music on the Human Back , 2010, 2010 Third International Conference on Advances in Computer-Human Interactions.

[12]  F. Vidal-Verdu,et al.  Graphical Tactile Displays for Visually-Impaired People , 2007, IEEE Transactions on Neural Systems and Rehabilitation Engineering.

[13]  Yon Visell,et al.  Tactile sensory substitution: Models for enaction in HCI , 2009, Interact. Comput..

[14]  Myoung-Jong Yoon,et al.  Psychophysical Experiment of Vibrotactile Pattern Recognition at Fingertip , 2006, 2006 SICE-ICASE International Joint Conference.

[15]  James Weiland,et al.  A wearable system for the visually impaired , 2010, 2010 Annual International Conference of the IEEE Engineering in Medicine and Biology.

[16]  Norman I. Badler,et al.  Collision Awareness Using Vibrotactile Arrays , 2007, 2007 IEEE Virtual Reality Conference.

[17]  S Weinstein,et al.  Intensive and extensive aspects of tactile sensitivity as a function of body part, sex, and laterality , 1968 .

[18]  Peter Korondi,et al.  Vibro-tactile feedback for VR systems , 2009, 2009 2nd Conference on Human System Interactions.

[19]  R. Klatzky,et al.  Haptic perception: A tutorial , 2009, Attention, perception & psychophysics.

[20]  R. Klatzky,et al.  There's more to touch than meets the eye: The salience of object attributes for haptics with and without vision. , 1987 .

[21]  Si-bok Yu,et al.  Vibrotactile Display for Driving Safety Information , 2006, 2006 IEEE Intelligent Transportation Systems Conference.

[22]  T P Way,et al.  Automatic visual to tactile translation--Part I: Human factors, access methods, and image manipulation. , 1997, IEEE transactions on rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society.

[23]  Ehud Ahissar,et al.  Importance of Temporal Cues for Tactile Spatial- Frequency Discrimination , 2001, The Journal of Neuroscience.

[24]  N. Otsu.  A threshold selection method from gray level histograms , 1979 .

[25]  Jack M. Loomis,et al.  Tactile letter recognition under different modes of stimulus presentation , 1974 .

[26]  Woodrow Barfield,et al.  Virtual environments and advanced interface design , 1995 .

[27]  Nikolaos G. Bourbakis,et al.  A 2D Vibration Array as an Assistive Device for Visually Impaired , 2007, 2007 IEEE 7th International Symposium on BioInformatics and BioEngineering.

[28]  J. Gibson.  The Senses Considered As Perceptual Systems , 1967 .