Development of a wearable ZigBee sensor system for upper limb rehabilitation robotics (original) (raw)

This paper presents a new tool for assessment and therapy in post-stroke upper-limb rehabilitation and a new wireless sensor technology to enhance rehabilitation robotics based on the ZigBee network of wearable Inertial Measurement Units (IMU) and Surface Electromyography (sEMG) sensor nodes. These sensor nodes will allow the measurement of kinematic and electrical muscle activity of patients in continuous therapy motion over all body segments as a Body Sensor Network (BSN). The IMU Sensor design was based on a direction-cosine-matrix DCM. The system validation was achieved with an optical motion tracking system in which cameras and IMU sensors recorded upper limb positions simultaneously during a standard gesture of reaching and grasping. The comparison between elbow flexion-extension angle in reaching and grasping movements obtained from both techniques shows equivalence. The analysis of IMU data signals for several movements demonstrates high repeatability intra and inter-subjects. I. INTRODUCTION stroke is the consequence of cell death within the brain relating to either internal bleeding or a blockage in one of the two main supplying arteries. Currently, it represents a major problem in clinical medicine being a leading cause of disability in the developed world [1]. Worldwide, 15 million people suffer a stroke, of which, 5 million die and another 5 million are left permanently disabled. Strokes are uncommon in people under 40 years; when they do occur, the main risk factor is high blood pressure [2]. Strokes remain a major public health concern in the United States, with more than 795,000 cases diagnosed annually. Over 50% of subjects present some paresis [3].