TURBot: A System for Robot-Assisted Transurethral Bladder Tumor Resection

Staging and treatment of nonmuscle-invasive bladder tumors using transurethral resection of bladder tumors (TURBT) is challenging due to limitations in intravesicular tool dexterity, visualization and risk of bladder wall perforation. Currently, TURBT is achieved via a rigid resectoscope. This dexterity limitation is exacerbated when tumors are located in the bladder neck region. To address these limitations, an endoscopic robotic system called TURBot was developed. The paper presents the design considerations, modeling, and control challenges that were addressed to enable the first robot-assisted in vivo TURBT. The design and control of a slave robot comprised of a multisegment continuum robot capable of deploying a micro snake-like continuum robot for control of an ablation laser, a grasper, and a fiberscope is presented. A strategy for constrained telemanipulation is presented based on the redundancy resolution with varying task dimension that is commensurate with the level of constraint experienced by the robot during transurethral deployment. In addition to evaluation in animals, TURBot resection is compared against manual resection in a mockup user study using a human bladder phantom. The contributions of this paper present key steps that pave the way toward successful clinical robot-assisted TURBT.