Transurethral Anastomosis after Transurethral Radical Prostatectomy: A Phantom Study on Intraluminal Suturing With Concentric Tube Robots

Robots to Improve Surgery for All

Surgeons around the world are now using robot-assisted tech to help them perform minimally invasive operations ranging from hernia repair and gall bladder removal to knee replacement and cancer-related colectomy, often manipulating the surgical tools from a computer console some distance from the patient. With names like da Vinci, Aquabeam, and Mako, robotic surgical technologies are becoming more common. As an example, industry powerhouse Intuitive reported in late 2021 that the number of surgical procedures using its robotic da Vinci system had topped 10 million globally [1].

Robotic-assisted genitourinary reconstruction: current state and future directions

With the widespread dissemination of robotic surgical platforms, pathology previously deemed insurmountable or challenging has been treated with reliable and replicable outcomes. The advantages of precise articulation for dissection and suturing, tremor reduction, three-dimensional magnified visualization, and minimally invasive trocar sites have allowed for the management of such diverse disease as recurrent or refractory bladder neck stenoses, and radiation-induced ureteral strictures, with excellent perioperative and functional outcomes. Intraoperative adjuncts such as near-infrared imaging aid in identification and preservation of healthy tissue. More recent developments include robotics via the single port platform, gender-affirming surgery, and multidisciplinary approaches to complex pelvic reconstruction. Here, we review the recent literature comprising developments in robotic-assisted genitourinary reconstruction, with a view towards emerging technologies and future trends in techniques.

Beyond Constant Curvature: A New Mechanics Model for Unidirectional Notched-Tube Continuum Wrists

This paper presents a new mechanics model for unidirectional notched-tube continuum wrists, a class of mechanisms frequently used to implement distal steering in needle-sized surgical robotic instruments. Existing kinematic models available for these devices are based on the simplifying assumption that, during actuation, all the notches undergo the same amount of deflection, so that the shape of a wrist can be approximated by an arc of constant curvature. This approach is analytically attractive, but, as we show in this paper, it can sometimes fail to provide good tracking accuracy. In this article, we provide a new model that relaxes the assumption above, and we report experimental evidence showing its superior accuracy. We model wrist deflection using Castigliano's second theorem, with the addition of a capstan friction term that accounts for frictional losses on the actuation tendon. Because notched-tube wrists are typically made of Nickel-Titanium (Nitinol), which has nonlinear stress-strain characteristics, we use a technique to obtain a local linearized approximation of the material modulus, suitable for use in the deflection model. The result of our modeling is a system of nonlinear equations that can be solved numerically to predict the wrist configuration based on the applied actuation force. Experimental results on physical specimens show that this improved model provides a more accurate estimate of wrist kinematics than prior models assuming constant curvature bending.