Clinical Evaluation of an Upper Limb Exoskeleton for Rehabilitation After Incomplete Spinal Cord Injury
Fitle, Kyle D
O'Malley, Marcia K.
Master of Science
In recent years robotic rehabilitation has emerged as an effective rehabilitation tool for motor impairment caused by multiple types of injuries and ailments. Incomplete spinal cord injury (SCI) is one of the injury types which is a prime candidate for robotic rehabilitation, but this field is relatively young and unexplored. The MAHI Exo II is a five degree-of-freedom (DOF) robotic exoskeleton which was designed for rehabilitation of the upper-limb following SCI or stroke. Upper-limb impairment is one of the factors which SCI patients rate as most significant in their post-injury decrease in quality of life. Therefore, the MAHI Exo II has the potential to make strides in improving the quality of life of patients in novel ways. This thesis presents research which has been done towards this aim. The first section presents a study on incomplete SCI rehabilitation with the MAHI Exo II. This study used the robotic system to provide resistance therapy for elbow flexion/extensioin, forearm pronation/supination, wrist flexion/extension, and wrist radial/ulnar deviation. The robot was also used to record position data in a backdriving-evaluation mode in order to analyze the change in subject movement quality over the course of therapy using several robotic quality of movement metrics. Subject improvement was also measured by standard clinical impairment measures used for SCI. Ten subjects enrolled in the study and eight finished the entire protocol. The results of this study spurred further research into more effective control and treatment strategies for the MAHI Exo II. In the second portion of this thesis, I present details on the Assist-as-Needed rehabilitation study. This experiment sought to apply assistive therapy with the MAHI Exo II using a novel adaptive control strategy and compare it to a non-adaptive controller in a parallel controlled study. This type of comparison has not been done before for robotic rehabilitation. The assistive nature of the controller allowed a wider inclusion criteria for incomplete SCI. The same joints were trained in this study and most of the same clinical and robotic measures were used to evaluate motor ability improvement. One of the secondary features of the study design is the sequential group assignment with co-variates minimization. The study is currently in progress at the time of this writing, but some preliminary results are presented in this section.