Virtual Reality technology is currently part of advanced physical rehabilitation therapy. However, several questions remain unanswered: Can this technology improve or even substitute the traditional methodologies? Can it really influence the nervous system or does moving within a virtual environment just motivate the individual to perform? In this paper we present the state of the art, the new advanced technology available and the most promising applications in this field. Finally we will introduce our research as a case study in the area.
INTRODUCTION TO VIRTUAL REHABILITATION
Following an authoritative description of traditional
rehabilitation therapy of motor disorders [
There are several universally accepted definitions of
Virtual reality (VR). One of the most clear was provided in
[
Virtual reality has the ability to simulate real-life tasks [
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VR offers the possibility to be precisely adapted to the patient’s therapy and to be specific. VR environments can provide realistic training for the patient in different scenarios and phases of the rehabilitation.
Repetition is crucial for the re-learning of motor functions and for the training of the cortical activity. This task has to be connected with the sensorial feedback on every single exercise.
Patient motivation is fundamental because active
cooperation of the patient is needed to achieve a more
functional outcome of the therapy. Motivation can be
improved by assigning a serious game format to the
therapy. In this way the training activity becomes more
attractive and interesting [
Remote data access is a fundamental requirement, especially for rural patients, since they do not have to travel to urban clinics.
In addition, VR represents a precise tool for the assessment
of the therapy during each session. The (tracked/saved)
data can be used by the rehabilitation specialists for
monitoring and managing the therapy [
By using VR in conjunction with Human Computer Interfaces (HCI) the training of daily life activities can be much improved in terms of time and quality. This approach permits a realistic and ergonomic training in a safe, interactive and immersive environment. In particular, VR provides the user with the possibility to perform tasks with a degree of safety which is normally not possible in the traditional rehabilitation. VR provides the rehabilitators with the possibility to influence qualitatively the training program, even in real-time. Another evident benefit is the patient’s engagment which is a key factor in rehabilitation (especially for children).
Examples of interfaces able to interact with VR are mice, joysticks, haptic interfaces with force feedback and motion tracking systems.
Several researches have shown that, during VR
rehabilitation, the movements are very similar to those used
in traditional therapy. Although they appear to be a bit
slower and less accurate, [
Some of the significant studies on the application of
robotics and VR for rehabilitation purposes shall be
introduced briefly. In [
Low Cost VR technology based
Rehabilitation using game Recently there has been an explosion of new technologies: especially low cost gaming devices based on optical tracking systems, radio frequencies, infrared cameras, and haptics are accessible to almost everybody.
Considering the general trend to decrease the costs for the
health systems all over the world one question comes up
urgently: can low-cost gaming technology serve the needs
of at least not severely injured patients with motor
disorders?
In terms of costs and deployment logistics it is evident that
a transition of the rehabilitation from traditional hospitals
or clinics to home environments can be a winning
challenge [
Many research groups have started the exploration of the use of such systems like Nintendo Wii® or more recently Kinect® as tools for rehabilitative therapy, including occupational and physical therapy.
An exploration of researches and low-cost programs is presented below.
An example of tele-rehabilitation can be found in [
Sony PlayStation2® was successfully used as low-cost VR
system in home environment by [
Sony PlayStation3® was used for tele-rehabilitation of
children with hemiplegia togheter with 5DT 5 Ultra (five
sensor) glove for the hand tracking, a computer, display,
keyboard and a mouse [
The release of the Wii® Fit (software) and Wii Balance
(platform) has stimulated new researches. The system
eBavir is a low-cost balance virtual rehabilitation system
based on the Wii® balance board.
[
Case Study: the HYPER project
We are currently working on providing a VR rehabilitation
platform for the HYPER project [
The project focuses its activities on new wearable NRMNP systems that will combine biological and artificial structures in order to overcome the major limitations of the current rehabilitation solutions to Cerebrovascular Accident (CVA) and Spinal Cord Injury (SCI).
VR, an important part of the complex system, was initially based on radio frequency tracking technology. This solution offers good tracking performances but it suffers from the use of many cables.
Considering the patient’s needs it is therefore not an optimal solution. Therefore we are now exploring a new wireless and inexpensive technology: Kinect®.
First results (see Fig. 2) are very promising and even if the accuracy of the tracking has to be measured exactly it seems that for this type of application the needs in terms of accuracy are not highly demanding. Additionally the tracking system appears to be robust enough to track the patient and the related robotic exoskeleton or neuroprosthetic devices on both upper and lower part of the body.
A limitation to be considered is that the Kinect® IR tracking suffers when the subject is illuminated strongly by the sun light. This is, however, a merely technological limitation which can be overridden.
Finally, a further part of our research concerns the conjunction between a Brain Computer Interface and virtual reality in order to create a good diagnostic and personalized environment in which it is possible to study the brain signals as answers to external (VR) stimuli or to assess the progress of the patient in the rehabilitation therapy. CONCLUSIONS This paper reviews the state of art, advantages and perspectives of Virtual Rehabilitation used in various forms of therapy. The recent introduction of new technology, originally developed for game purposes, provides a number of challenges and increases the possibilities of Virtual Rehabilitation to gain wide acceptance.
We have presented, as a case study, the first development status of an advanced system that combines VR based on game technology with a hybrid NR and MNP system for functional compensation of motor disorders.
ACKNOWLEDGMENTS This paper is a dissemination activity of the HYPER project funded by CONSOLIDER-INGENIO 2010, Spanish Ministry for Science and Innovation.