Artificial Intelligence and the Future of Surgical Robotics

Abstract

In 2016, Shademan et al reported complete in vivo, autonomous robotic anastomosis of porcine intestine using the Smart Tissue Autonomous Robot (STAR).1,2 Although conducted in a highly controlled experimental setting, STAR quantitatively outperformed human surgeons in a series of ex vivo and in vivo surgical tasks. These trials demonstrated nascent clinical viability of an autonomous soft-tissue surgical robot for the first time. Unlike conventional surgical robots which are controlled in real-time by humans and which have become commonplace in particular subspecialties, STAR was controlled by artificial intelligence (AI) algorithms, and received input from an array of visual and haptic sensors. Applications of AI to clinical data for diagnostic purposes have already begun to demonstrate capability approximating that of specialist physicians.3,4 Consequentially, clinical AI has received much attention from within and outside the medical community.5 The STAR trials give clinical AI a surgical context and provide a glimpse into the future, should autonomous surgical devices be further developed. Nevertheless, their development must be rationalized and, for widespread utilization, they must confer either technical or financial advantages over conventional surgical techniques. We henceforth expand upon how this may unfold. DEFINITIONS OF AUTONOMY The International Organization for Standardization (ISO 8373:2012) defines autonomy as “an ability to perform intended tasks based on current state and sensing without human intervention.” However, “autonomy” is not a singular state, but rather a scale in which the degree of human intervention is traded against full independence (Fig. 1). Examples of robotic surgical devices of variable autonomy include the DaVinci (Intuitive Surgical, Sunnyvale, CA) a “master-slave” robot completely dependent upon human control; the TSolution-One (previously ROBODOC; THINK Surgical, Fremont, CA) orthopedic robot; and the Mazor X (Mazor Robotics, Caesarea, Israel) spinal robot. The latter 2 offer reduced levels of human input for a limited range of surgical tasks. Partially autonomous robotic devices such as the CyberKnife (Accuray, Sunnyvale, CA) are already in clinical use at present; however, as this uses external radiation beams, it cannot be truly considered a “surgical robot” in the context of this piece.FIGURE 1: A comparison between the evolution of autonomous vehicles and autonomization of surgery, adapted from Topol (2019), Figure 5. This concept is based upon differing levels (0–5) of autonomy based upon technology and requirements for vehicles, with analogies drawn between vehicles and the performance of surgery. Level 0 encompasses the traditional and historical practice of surgery as it exists today: a human surgeon performs all aspects of the operation using hand-held tools. At level 1, intraoperative image guidance may be performed in real time, for example, intraoperative fluoroscopy or stereotactic navigation, but humans still perform all aspects of physical intervention. At level 2, robotics combined with image guidance may assist in the surgical procedure, for example, the TSolution-One or Mazor X robots. These permit a reduced level of human input by automating critical components of the procedure (such as guiding trajectories of instruments), to reduce errors. At level 3, the device is capable of both navigating and performing limited surgery. The real-life analogy to this level of automation is the CyberKnife stereotactic oncology robot, which plans and conducts “surgery” autonomously. As it uses external radiation beams, it is not strictly “surgery” and its clinical versatility is limited. For level 4 autonomy, the robot is capable of performing a wide-range of surgical procedures largely unaided. Humans may be required for the most complex portions of the procedure, or alternatively solely for supervision (or for legal purposes) and assistance should the robot require it. Level 5