A Haptic Guidance System for Stroke Rehabilitation

Abstract: Stroke is the third largest cause of death in Sweden. In 2005, 30.000 people in Sweden suffered from a stroke. The consequences of a stroke varies, but the most common disability among stroke survivors is abnormal reaching movements, which is the primer reason for limitations in activities of everyday living. Rehabilitation is essential in order to get back to everyday life. Physical assistance (or guidance) is used in rehabilitation by physiotherapists and occupational therapists to help a patient through a dicult movement for example. Today, this guidance is limited to be performed by medical personnel. With the technology of virtual environments (VE) and haptics – force feedback from a computer – there is a possibility to create guidance which does not need medical personnel. This should be used as a complement to the traditional therapy. The intention of this work is to create an invisible guidance eld, which should guide a patient's hand to a desired movement pattern, i.e. aid the patient to perform a task in a virtual environment with haptics. This guidance is added to an already existing assessment tool, which is a part of the Curictus AB rehabilitation system. The guiding system is implemented using SenseGraphics AB's H3D API. To create the feeling of guidance and a guidance eld, the Volume Haptics Toolkit, developed by Dr. Karljohan Lundin Palmerius at Linköping University, was used. The basic idea of the algorithm is to calculate an orientation vector, for every position, in which direction the guidance should guide the patient. The guidance, which is generated via a haptic device, is adaptive to the patient's movements and always guides the patient towards the target in a smooth trajectory.