Robotic rehabilitation for the restoration of hand motor function following stroke
Stroke is the most common cause of severe disabilities in the developed world. Over 1/3 of stroke victims sustain long-term moderate to severe disabilities. This can include motor limitation in the extremities with hand function often impaired and only 14% of stroke survivors recovering full sensory motor function in the arm.
In England and Wales over 130,000 people have strokes every year and there are more than 900,000 people suffering from the after effects of a stroke living in England. Half of the current stroke survivors in the UK with affected motor skills are therefore dependent on others for activities of daily living. A critical part of regaining independence is the use of the hand for tasks such as pinching or grasping an object in order to manipulate it within everyday life.
15 DOF exoskeleton
This has lead to the development of a novel, 15 degree of freedom, parametrically designed exoskeleton, including a novel four-bar mechanism for supporting the opposition motion of the thumb. The exoskeleton is based around a kinematic model of the human hand as it grasps an object and is fully customisable within a CAD environment. This allows for the mechanical joints to lie coincident to natural joint axes, improving bio-compatibility and the ability of the device to offer natural grasping motion. Control complexity is offset into embedded mechanical intelligence through the use of a novel synchro-motion pulley system which provides the greatest range of functional motion possible with a reduced number of actuators.
A prototype exoskeleton has been assembled and assessed in its ability to deliver normal hand function for everyday activities. Tests with healthy subjects and those affected by stroke have shown positive results with the device feeling comfortable with natural grasping motions allowing subjects to complete a range of tasks. It should be noted that unfortunately this technology is not currently available for distribution for clinical or home use. However, it is hoped that with further funding, more research can be undertaken to make home-based hand exoskeletons a more practical option than ever before.
- Prof. Sanja
Tel: +44 (0) 117 32 81301