Stretchable origami robotic arm with omnidirectional bending and twisting.

Inspired by the embodied intelligence observed in octopus arms, we introduce magnetically controlled origami robotic arms based on Kresling patterns for multimodal deformations, including stretching, folding, omnidirectional bending, and twisting. The highly integrated motion of the robotic arms is attributed to inherent features of the reconfigurable Kresling unit, whose controllable bistable deploying/folding and omnidirectional bending are achieved through precise magnetic actuation. We investigate single- and multiple-unit robotic systems, the latter exhibiting higher biomimetic resemblance to octopus' arms. We start from the single Kresling unit to delineate the working mechanism of the magnetic actuation for deploying/folding and bending. The two-unit Kresling assembly demonstrates the basic integrated motion that combines omnidirectional bending with deploying. The four-unit Kresling assembly constitutes a robotic arm with a larger omnidirectional bending angle and stretchability. With the foundation of the basic integrated motion, scalability of Kresling assemblies is demonstrated through distributed magnetic actuation of double-digit number of units, which enables robotic arms with sophisticated motions, such as continuous stretching and contracting, reconfigurable bending, and multiaxis twisting. Such complex motions allow for functions mimicking octopus arms that grasp and manipulate objects. The Kresling robotic arm with noncontact actuation provides a distinctive mechanism for applications that require synergistic robotic motions for navigation, sensing, and interaction with objects in environments with limited or constrained access. Based on small-scale Kresling robotic arms, miniaturized medical devices, such as tubes and catheters, can be developed in conjunction with endoscopy, intubation, and catheterization procedures using functionalities of object manipulation and motion under remote control.

Flexible ureteroscope capable of acute-angled and balanced omnidirectional bending based on soft and flexible porous tube and crossed control wiring.

Flexible ureteroscopes (fURSs) have performance limitations in accessing acute-angled calyxes and omnidirectional bending. We propose and develop a fURS based on a soft and flexible porous tube and crossed control wiring to overcome these limitations. The fURS prototype comprises a flexible solid polyamide-12 tube and a stretch-retractable expanded polytetrafluoroethylene distal tube with 40% porosity connected by a unique cylindrical wire-routing hook (CWH). The series tube includes four crossed but not contacting loop-formed control wires to provide balanced omnidirectional bending and optimized distal tube bending performance. Bending performance was assessed compared with a conventional fURS, and feasibility studies were performed using a renal phantom. The prototype achieved a 275° omnidirectional maximum bend angle by combining up-down and right-left directions. The bent shape was more compact than the conventional fURS. Thus, the prototype achieved approximately a 1.6-fold larger maximal active bending angle within the restricted environment and a 5.5-fold larger passive bending angle. The crossed control wiring design reduced CWH offset distance by about 75% compared with conventional straight wire routing. The prototype exhibited considerably improved steering performance, exemplified by its ability to access an acutely angled calyx. Our design could improve treatment outcomes and shorten operation times associated with calyceal stone removal.

A Novel Flexible Ureteroscope with Omnidirectional Bending Tip Using Joystick-Type Control Unit (URF-Y0016): Initial Validation Study in Bench Models.

Purpose: The conventional flexible ureteroscope has limited access into the lower calix and often causes biomechanical stress to surgeons. Recently, a novel flexible ureteroscope with an omnidirectional bending tip with a joystick-type control unit (URF-Y0016; Olympus, Japan) was developed. We verified the operability and ergonomics of the URF-Y0016 compared with that of the conventional flexible ureteroscope (URF-P6) in bench models. Materials and Methods: Twenty-five medical students with no experience in performing ureteroscopic manipulation were randomly assigned to URF-Y0016 and URF-P6 leading groups in a crossover study. The task was performed using a simple model as an exploratory experiment and an artificial kidney model as an evaluation experiment. We compared the task completion times of both groups, while the factors influencing task completion time were entered into a multivariate model. The ergonomics of endourology were compared using a validated questionnaire. Results: The task completion time in the URF-Y0016 group was significantly shorter than in the URF-P6 group (p < 0.001). The URF-Y0016 group showed no difference in task completion time between each renal calix, whereas in the URF-P6 group the task completion time in the lower calix was significantly longer than that in other calices (p < 0.001). In multivariate analysis, the model of flexible ureteroscope used significantly influenced the task completion time (p < 0.001). The ergonomics of the URF-Y0016 group were significantly better than those of the URF-P6 group (p = 0.001). Conclusions: URF-Y0016 may offer benefits in ureteroscopy performance over the conventional flexible ureteroscope.