Technology

INTRODUCTION

PHANToM, means Personal HAptic iNTerface Mechanism, was developed at MIT as a relatively low cost force feedback device for interacting with virtual objects. Phantom device is a robot arm that is attached to a computer and used as a pointer in three dimensions, like a mouse is used as a pointer in two dimensions.

ABOUT PHANTOM

The PHANToM interface's novelty lies in its small size, relatively low cost and its simplification of tactile information. Rather than displaying information from many different points, this haptic device provides high-fidelity feedback to simulate touching at a single point. It just like closing your eyes, holding a pen and touching everything in your office. You could actually tell a lot about those objects from that single point of contact. You'd recognize your computer keyboard, the monitor, the telephone, desktop and so on.

A Phantom device and the Phantom Force Feedback extension can also be used to trace paths and/or move models in the absence of volume data. Although there will not be force feedback in such cases, the increased degrees of freedom provided by the device as compared to a mouse can be very helpful. The Phantom Force Feedback extension of Chimera allows a Phantom device to be used to guide marker placement within volume data. It is generally used together with Volume Viewer and Volume Path Tracer. SensAble Technologies manufactures several models of the Phantom. The device is only supported on SGI and Windows platforms. SensAble Technologies has announced that in summer of 2002 it will add support for Linux and drop support for SGI. The least expensive model (about $10,000 in 2001), the Phantom Desktop, is described here.

To integrate the PHANToM with a projection screen virtual environment several obstacles need to be overcome. First, the PHANToM is essentially a desktop device. To use it in a larger environment the PHANToM must be made mobile and height adjustable to accommodate the user.

For this we use

Phantom Stand

The phantom stand was designed to permit positioning, height adjustment, and stable support of the PHANToM in the virtual environment. To avoid interference with the magnetic tracking system used in the environment, the phantom stand was constructed out of bonded PVC plastic and stainless steel hardware.

KEY BENEFITS

o High fidelity, 3D haptic feedback
o The ability to operate in an office/desktop environment
o Compatibility with standard PCs and UNIX workstations
o A universal design for a broad range of applications
o Low cost device
o Used to trace paths