Thesis Abstract

Abstract
Pediatric gait rehabilitation is a critical aspect of therapy for children with neurological disorders or injuries affecting their ability to walk. In recent years, robotic technologies have been increasingly utilized in the design and implementation of gait rehabilitation programs for pediatric patients. These robotic systems offer the advantages of providing high-intensity, repetitive, and task-specific training in a controlled and engaging manner. The design and evaluation of pediatric gait rehabilitation robots present unique challenges due to the varying needs and capabilities of children of different ages and sizes. Customization and adaptability are key features that need to be incorporated into the robot design to cater to the specific requirements of pediatric patients. Furthermore, safety considerations are paramount when designing robotic systems for use with children, requiring stringent adherence to safety standards and the implementation of fail-safe mechanisms. The evaluation of pediatric gait rehabilitation robots involves assessing the effectiveness of the robotic interventions in improving gait patterns, muscle strength, balance, and overall functional abilities in pediatric patients. Outcome measures such as gait speed, stride length, and gait symmetry are commonly used to quantify improvements resulting from robot-assisted therapy. Additionally, the evaluation process includes feedback from therapists, caregivers, and patients to ensure that the robotic system is well-accepted and integrated into the rehabilitation program. Several studies have demonstrated the positive impact of pediatric gait rehabilitation robots on the functional outcomes of children with conditions such as cerebral palsy, spinal cord injury, and traumatic brain injury. These studies have shown improvements in gait parameters, muscle strength, and overall mobility following robot-assisted therapy. Moreover, the interactive and engaging nature of robotic systems has been found to enhance motivation and compliance among pediatric patients, leading to better treatment outcomes. Future research in this field should focus on further customization of robotic systems to address the specific needs of different pediatric populations and on optimizing the training protocols to maximize therapeutic benefits. Collaboration between engineers, therapists, and healthcare providers is essential to ensure the successful integration of robotic technologies into pediatric gait rehabilitation programs and to advance the field towards more effective and accessible rehabilitation solutions for children with mobility impairments.

Thesis Overview

Gait therapy methodologies were studied and analyzed for their potential for pediatric patients. Using data from heel, metatarsal, and toe trajectories, a nominal gait trajectory was determined using Fourier transforms for each foot point. These average trajectories were used as a basis of evaluating each gait therapy mechanism.
An existing gait therapy device (called ICARE) previously designed by researchers, including engineers at the University of Nebraska-Lincoln, was redesigned to accommodate pediatric patients. Unlike many existing designs, the pediatric ICARE did not over- or under-constrain the patient’s leg, allowing for repeated, comfortable, easily-adjusted gait motions. This design was assessed under clinical testing and deemed to be acceptable.
A gait rehabilitation device was designed to interface with both pediatric and adult patients and more closely replicate the gait-like metatarsal trajectory compared to an elliptical machine. To accomplish this task, the nominal gait path was adjusted to accommodate for rotation about the toe, which generated a new trajectory that was tangent to itself at the midpoint of the stride. Using knowledge of the bio-mechanics of the foot, the gait path was analyzed for its applicability to the general population.
Several trajectory-replication methods were evaluated, and the crank-slider mechanism was chosen for its superior performance and ability to mimic the gait path adequately. Adjustments were made to the gait path to further optimize its realization through the crank-slider mechanism.
Two prototypes were constructed according to the slider-crank mechanism to replicate the gait path identified. The first prototype, while more accurately tracing the gait path, showed difficulty in power transmission and excessive cam forces. This prototype was ultimately rejected. The second prototype was significantly more robust. However, it lacked several key aspects of the original design that were important to matching the design goals. Ultimately, the second prototype was recommended for further work in gait-replication research.