Abstract
Estimate intentional joint angle easily and accurately is important for developing a powered prosthetic hand which can realize upper limb amputee’s intentional motion. We proposed the joint angle estimation method using the muscle bulge movement on the forearm skin surface derived from the deformation of the muscle while muscle contraction. We hypothesized a simple relationship between the muscle bulge movement longitudinally along a muscle and the corresponding joint angle, because the muscle contraction causes the change in the joint angle. In this paper, we evaluated the feasibility of the muscle bulge movement for wrist joint angle estimation by confirming the signal characteristics of the proposed signal. From the experimental results with five non-amputated subjects, we extracted a linear relationship from the raw data with a high determination coefficient as 0.94. Using the function eared from the raw data, we achieved the joint angle estimation error as 8.05［°］which is similar to that of using surface EMG in related work. We will develop a joint angle control method using the muscle bulge movement for a powered prosthetic hand with upper limb amputee.
