Design and development of a gravity-balanced device for the upper limb

Abstract

Patients suffer with neuromuscular diseases often have limited muscle force, and many rely on mobile arm supports to move their arms. In this paper, the author purposes a device to balance the upper limb to eliminate the effect of gravity force on the upper limb. The designed device includes the following features: 1) it is passive, the device only use springs to achieve gravity balancing. 2) The device has two adjusting mechanism, one for the level of gravity balancing and another for the lifting force adjustment. 3) The device come with a quick release mount to allow mounting of other medical device. A number of methods have been purposed in the literature to gravity-balance upper limb. Here, the author uses the end point manipulator together with the ideal spring mechanism in the final design. A method to examine the functionality and effectiveness of the device using the Electromyography (EMG) technique has also been purposed in this paper.