Design Considerations for Continuum Robot Actuation Units Enabling Dexterous Transurethral Bladder Cancer Resection

The last decade has seen rapid growth in exploring the potential of continuum robots for a variety of surgical applications. The design of these robots requires unique electro-mechanical architectures of actuation units that satisfy operational requirements of precision, workspace, and payload capabilities. This paper presents the task-based design process of a compact nine degrees of freedom actuation unit for transurethral resection of bladder tumor (TURBT). This actuation unit has a unique modular architecture allowing partial decoupling of actuation, force and position sensing in a compact modular format. The derivation of task specifications based on kinematic simulations takes into account workspace, accuracy and force application capabilities for TURBT. Design considerations for supporting modularity, serviceability, sterilization, and compactness are presented. The detailed exposition of the design process serves as a case study that will be helpful for other groups interested in the development and integration of surgical continuum robots.