Medicine Meets Virtual Reality II
San Diego, California
January 27-30, 1994
Suzanne Weghorst
Jerrold Prothero
Thomas Furness
Human Interface Technology Laboratory
University of Washington, FJ-15
Seattle, WA 98195
Denis Anson
Department of Rehabilitation Medicine
University of Washington
Thomas Reiss
San Anselmo, California
Abstract
Many people with Parkinson's Disease exhibit a form of akinesia characterized by progressively greater difficulty in initiating and sustaining walking. This symptom can be mitigated by treatment with drugs such as L-dopa, a chemical precursor of the natural neural transmitter dopamine, but usually not without unwanted side effects. We present a novel technique for eliciting walking in unmedicated akinetic Parkinson's patients, one which may prove to be a useful new therapeutic approach to other common movement disorders.
Using a commercial field-multiplexed head-up video display (the Virtual Vision(TM) Sport eyewear), we have simulated an effect called kinesia paradoxa, the triggering of normal walking behavior in akinetic Parkinson's patients by external cues, such as the placement of physical obstacles at their feet. While object cuing of kinesia paradoxa is a well-known phenomenon, it has heretofore not provided a practical treatment approach. Near-normal walking can be elicited, even in severely akinetic patients, by presenting collimated virtual images of objects and abstract visual cues moving vertically through the visual field at speeds that emulate normal walking. The combination of image collimation and animation speed reinforces the illusion of space-stabilized visual cues at the patient's feet. We have also found that appropriately placed laser spots can be used to trigger the response, but these may not be as useful under a variety of lighting conditions and patient activities.
The research team is currently characterizing the design requirements for the display device and for the dynamic graphics presented. Once these are more fully defined the device can be customized optimally for this application, potentially allowing many Parkinson's patients to walk unassisted without medication, in at least some stages in the development of the progressive disorder.
Collaborators on the project include the original subject, who suggested the idea of using virtual imagery and has conducted much of the research on himself. HITLab researchers are working with medical consultants at the University of Washington Medical Center and the Parkinson's Institute in Sunnyvale, California, to further define the phenomenon and to explore other related uses of virtual imagery.