et al., 1994). Their next series of studies will involve the use of bioelectric signals based on muscle activity to provide disabled children with the capability to play Nintendo-type computer games now being played by the general population. Other centers working on the same problem, such as the Children's Hospital in Boston, have proposed studies to examine the motor output capacity of disabled individuals and to match that capacity with control interfaces making use of multimodal outputs.
Loma Linda researchers are also engaged in having disabled persons work with virtual objects generated by a computer as a means to begin rehabilitating their motor skills. For example, an individual could practice manipulating a virtual object at a weight they could handle. It is believed that this practice is useful even if the virtual object weighs less than the real one. In related work, Greenleaf Medical Systems (Greenleaf, 1994) is working toward using VEs to enable individuals to perform tasks that they could not perform in the real world. An example provided by researchers at Greenleaf is creating a VE in which a cerebral palsy sufferer could operate a switch board.
Weghorst et al. (1994) are experimenting with using virtual objects to treat walking disorders associated with Parkinson's disease. According to the authors, objects placed at the feet of these patients may serve to stimulate a walking response. Since using real objects is not a particularly practical approach, virtual objects are being tried with some success. Specifically (p. 243):
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.
In another example, Greenleaf Medical Systems is in the process of adapting the VPL DataGlove and DataSuit for use in measuring the functional motion of a disabled person and recording progress over time. Moreover, researchers are working on developing a gesture control system designed to enable individuals wearing the DataGlove to perform complex control activities with simple gestures and on creating a system that will recognize personalized gestures as speech signals. In the latter example, the DataGlove would receive the hand gestures and translate them into signals sent to a speech synthesizer, which then "speaks" for the individual wearing the DataGlove. All of these products are in the early development stage.
In yet another example, VE technology is being used by architects to design living and working spaces for the disabled. The technology now