GhostGlove: Haptic Existence of the Virtual World
Kouta Minamizawa*

Sho Kamuro

Souichiro Fukamachi

Naoki Kawakami

Susumu Tachi

The University of Tokyo

Encounter(Position)

Pressure(Hardness)

Contour following(Surface shape)

Stroke(Texture)

Grasping(Global shape)

Bimanual enclosure(Volume)Unsupported holding(Weight)

Figure 1: The categorized behaviors and perceptions that are represented by our proposed method.

1. Introduction
In the real world, we usually do not perceive haptic sensations
consciously. However, if the haptic sensations are absent or ifthey are not of the desired quality, it would result in discomfort,
and the existence of the world would be degraded. In order toeliminate the feelings of discomfort and represent genuine
feelings of the existence of objects in virtual reality interactions,as shown in figure 2, we show that haptic sensations play adecisive role in inciting cognitive functions in a virtualenvironment. There are many researches on haptic displays forvirtual reality interactions with the hand, such as CyberTouch andCyberGrasp [Immersion Corp.]. However, the represented
sensation is still inadequate to provide us with the experience offeeling the definite existence of virtual objects or virtual creatures.
Generally, it is considered that a complex and expensive device isrequired to provide realistic haptic sensations; many attempts tosimplify the device would result in poor sensations, for example,
simple vibrations. To merge the simplicity of the device andrealistic sensation of existence, we propose a novel wearable
haptic interface named “GhostGlove.” This device generates
natural and realistic haptic sensations over the entire hand—on
each finger and the palm—and integrates the perceptions on theentire hand along with the visual sensations to enables us torecognize the existence of the virtual world.

2. Method
Usually, the palm is used for a rough and quick recognition of thesize and shape of an object, while the fingers are used for
dexterous manipulations. We found that the interactive
combination of the cutaneous perceptions on the palm and fingers
is effective in the haptic recognition of the objects. Based on thestudy on exploratory procedures [Lederman and Klatzky 1987],
we categorized the behavior in human-object interactions byfocusing on the relative motion of the palm and the object asshown in figure 1. The direction of the motions represented by
Encounter and Pressure are perpendicular to the object surface,
while those represented by Contour following and Stroke arelateral to the surface. Bimanual enclosure, grasping, andunsupported holding are examples of static contact. We thenimplemented the prototype device shown in figure 3 to reproduce
the corresponding cutaneous perceptions in each relative motion.
The mechanism for the reproduction of the sensation on eachfinger and the palm is based on our unique technology to provide
significantly realistic sensations of touch and the dynamics of*e-mail: kouta_minamizawa@ipc.i.u-tokyo.ac.jp

Copyright is held by the author / owner(s).
SIGGRAPH 2008, Los Angeles, California, August 11–15, 2008.
ISBN 978-1-60558-466-9/08/0008

Figure 2: Conceptual representation of our proposed system.
The user with HMD and the devices on both hands can see andtouch the VR object. The haptic sensation is represented
interactively corresponding to the user's motion.

Figure 3: Prototype device and closeup of index finger
virtual objects [Minamizawa et al. 2007]. By reproducing thevertical and shearing forces on the fingerpad by this simple
mechanism, the device could generate high-responsive and precise
haptic interactions of the dynamic motion of the virtual objects.
We extended this method to the entire hand including the palm,
and also confirmed the effectiveness of bimanual coordination
particularly in the perception of volume and surface.

3. Summary
We proposed a novel haptic interface to be worn over the entire
hand. This interface allows realistic and responsive haptic
interactions in virtual reality environments via a simple methodthat considers the importance of the unconscious perception ofhaptic sensations for recognizing the existence of the external
world. GhostGlove provides an unprecedented feeling of thedynamics of virtual objects and the vitality of virtual creatures.

References
LEDERMAN, S. J. AND KLATZKY, R. L. 1987. Hand-movements: A window
into haptic object recognition. Cognitive Psychology, 22, 421-459.
MINAMIZAWA, S. FUKAMACHI, K., KAJIMOTO, H., KAWAKAMI, N. AND
TACHI, S. 2007. Gravity Grabber: Wearable Haptic Display to PresentVirtual Mass Sensation, In Proceedings of ACM SIGGRAPH 2007,Emerging Technologies.