COMPUTER ASSISTED STROKE REHABILITATION - THE POSSIBILITIES OF HAPTICS and VIRTUAL REALITY

Virtual Reality (VR) has now emerged as a promising tool in many domains of rehabilitation. As a consequence an additional meaning of the abbreviation VR has emerged, namely Virtual Rehabilitation (www.iwvr.org). With the availability of VR technology, it becomes possible to examine and train human motor behaviour in computer-generated scenarios. The aim of this thesis was to explore motor training with haptics and VR in the so called chronic phase after stroke and to see if improvement was reflected in Activities of Daily Life (ADL). (A haptic device gives the impression of sensation feedback to the users when touching virtual objects.) A further aim was to establish normative kinematic reference values, so that the VR system in the future could be used to evaluate persons with neurological deficits in daily clinical practice. Paper I describes the implementation of a VR application in stroke rehabilitation. A Single-subject experimental design (AB) was used to provide intervention effects on five hemiparetic stroke subjects. Velocity, time and hand path ratio (reflecting superfluous movements), were the outcome measures. The Box and blocks test (BBT) and Assessment of motor and process skills (AMPS) were used as a correlate to the quantitative kinematic information of the VR-assessment. In paper II, fifty-eight normal subjects performed three-dimensional hand movements in a virtual environment. Test-retest was evaluated on all subjects. Normative kinematic reference values were obtained on velocity, time and hand path ratio and peak velocity. Velocity and acceleration vs. time graphs revealed the movement pattern. Both studies demonstrate that this technology can provide a quantitative analysis of hand movement for strokeand normal subjects. In paper I improvements were noted in velocity, time and hand path ratio for all subjects. One patient improved in occupational performance, i.e. improvement was reflected in activities of daily living. In paper II, no difference was found between test and retest. The limits of agreement revealed that changes in an individual's performance cannot be detected. VR technology can provide a quantitative analysis of detecting small variations not detectable with the naked eye. The VR upper extremity test takes less than a minute to complete and produces kinematic data. The general experience with the VR application approach suggests that this treatment concept might be successful in motor and cognitive rehabilitation, with a wide range of applicability. This thesis is a step closer towards understanding the possibility of VR technology and how it could provide measurements to examine and train human motor behaviour in computer-generated scenarios.