Development of a Robotic Lewis Rat Ankle & Foot for Advanced Testing and Evaluation of Regenerative Treatment Solutions and the Innovative Impact of Regulatory Challenges Faced When Transitioning from Animal Testing to Human Clinical Trials

This thesis examines the performance of a robotic Lewis Rat hindlimb constructed at the University of Virginia. The model was developed to simulate gait and muscle force dynamics seen in Lewis Rats when walking. Developed as an engineering capstone project, this actuated hindlimb model recreates the ankle dorsiflexion and plantarflexion movement within an average of 11.75 degrees of anatomical values. As this statistic achieves a Pearson correlation coefficient of 0.9047 compared to live animal data, this robotic system exemplifies how physical modeling can serve as a bridge between computational simulations and our understanding of complex diseases and injuries. Future goals of this model include enabling artificial injury simulation and theoretical testing of therapeutic interventions for volumetric muscle loss (VML), thereby offering a viable alternative to large-scale animal experimentation. In light of this, this thesis also investigates the regulatory and ethical challenges seen with animal testing in drug development. Despite decades of increasing integration with biomedical research, animal testing has proven inefficient and expensive, with a high failure rate when transitioning from animal to clinical trials. This thesis argues that animal testing is not only an unethical practice but also scientifically ineffective. Through a multifaceted approach that incorporates policy analysis, ethical theory, and comparative evaluation of New Approach Methods (NAMs), this research highlights promising alternatives to animal testing, such as organ-on-a-chip, 3D bioprinting, and AI-driven computational models. This study also examines the lag between technological advancement and regulatory adoption, advocating for a responsible innovation framework that prioritizes humane, cost-effective, and more insightful drug development practices. Ultimately, this paper calls for a shift away from animal testing toward more advanced and human-relevant methodologies.