A novel robot-assisted flexible ureteroscope system(RAFUS): design, learning curve, ergonomics, and preclinical...

Traditional manual flexible ureteroscopy imposes a steep learning curve and severe ergonomic burdens. Furthermore, many existing robotic systems lack integrated optical fiber manipulation. To overcome these limitations, this paper presents the design and evaluation of a novel RAFUS that achieves precise control over four key degrees of freedom, including automated laser fiber delivery, via a miniaturized operating handle. For systematic evaluation via an integrated experimental platform, learning curve analysis was conducted, and a novel mean amplitude spectral density (MASD) metric was combined with Mean Frequency (MNF) to form a robust joint index for ergonomic assessment, followed by in vivo preclinical validation. Experimental results based on an exponential learning model demonstrate that the RAFUS not only significantly shortens the learning curve but also minimizes inter-operator variance, reducing the average exploration time from 435 ± 186.6s to 272 ± 69.9s. With the MASD metric effectively overcoming involuntary mechanical unloading and physiological micro-tremors, the joint evaluation demonstrated severe asymmetric fatigue in manual operations, primarily stressing the bilateral wrists and the right biceps brachii, evidenced by a 17.15% MNF decrease in the latter. Conversely, the robotic mode offers operators improved ergonomics. Finally, in vivo canine renal explorations successfully validated the safety and diagnostic reliability of the device. The proposed RAFUS shortens the learning curve and improves ergonomics, demonstrating potential for clinical translation.