PHANTOM LIMB / VIRTUAL ARM

Amputees often experience a phantom limb. It is now possible to have a phantom sensation of an additional arm - a virtual arm - albeit visual rather than visceral. The Virtual Arm is a computer-generated, human-like universal manipulator interactively controlled by VPL VR equipment.

Using Datagloves with flexion and position-orientation sensors, and a GESTURE-BASED COMMAND LANGUAGE allows real-time intuitive operation and additional extended capabilities. Functions are mapped to finger gestures, with parameters for each function, allowing elaboration.

Some of the Virtual Arm's extended capabilities include "stretching" or telescoping of limb and finger segments; "grafting" of extra hands on the arm; and "cloning" or calling up an extra arm.

The "record and playback" function allows the sampling and looping of motion sequences. A "clutch" command enables the operator to freeze the arm, disengaging the simulating hand. For teleoperation systems, features such as "locking" allow the fixing of the limb in position for PRECISE OPERATION WITH THE HAND. In "micro mode" complex commands can be generated with a single gesture, and in "fine control" delicate tasks can be completed by the TRANSFORMATION OF LARGE OPERATOR MOVEMENTS TO SMALL MOVEMENTS OF THE VIRTUAL ARM.

The Virtual Arm project was completed with the assistance of Mike Papper, Craig McNaughton, James Boyle, Dean Hansen and Robert Webb - supervised by Mike Gigante at the RMIT Advanced Computer Graphics Centre, CITRI, Melbourne.