Patients Post-cardiothoracic Surgery

The goal of this clinical trial is to establish the safety, feasibility, and preliminary findings of overground robotic exoskeleton early ambulation (ORE-EA) compared to usual care early ambulation (UC-EA) in the rehabilitation of patients who have had cardiovascular or thoracic surgery. The main questions it aims to answer are: * Is there a difference between groups in time between surgery and ambulation? * Are there differences in safety and feasibility?