navigation and control. Although this work will largely be driven by research novelty rather than clinical need, it will add to the technological toolbox. Whereas early validation experiments were academic in nature with little attention paid to eventual medical applications, there was a growing emphasis over the decade toward creating prototype systems such as those noted above that could perform actual medical procedures. For continuum robots to reach the clinic, this line of research will be increasingly important in the years ahead. There are several reasons for this. First, the creation and demonstration of a procedure-specific prototype is the fundamental step required to de-risk the technology for commercialization. It also enables a firstcut cost-benefit comparison with current clinical practice. Thus, these technology demonstration projects can directly lead to commercialization efforts. Equally important, procedure-specific prototypes serve to identify critical knowledge gaps that spur future fundamental research. DISCUSSION The number of papers on medical robotics has grown exponentially from less than 10 published in 1990 to more than 5200 in 2020. Consequently, the fraction of papers published during the past decade is more than 80% of the total. These publications span the entire range of the research pipeline. Engineering journal publications have covered the creation of new robotic technologies for medical applications and the design of new medical robots. Medical journal publications have completed the research process by evaluating existing robot designs in human patients. Although the field cannot yet point to comprehensive clinical trials that show that robotic surgical procedures provide improved procedural outcomes for patients (70) or reduced procedure cost compared with nonrobotic surgery (71), a number of patient benefits have been demonstrated. These include shorter hospital stays, faster recuperation, fewer reoperations, and reduced blood transfusions (71). For surgeons, robots provide improved ergonomics, leading to reductions in neck and back pain (72) as well as hand and wrist numbness (73) with less physical and mental stress compared with direct hand-controlled procedures (74). These factors increase a surgeon’s quality of life and could potentially lengthen their career. Studies have also shown that robotics can markedly reduce radiation exposure to both the surgeon and the patient (75). To further this progress, it would be beneficial to channel future engineering research efforts in the most promising directions. This requires developing an understanding of how robots and their underlying technologies add value in medicine. Whereas in almost all other industries, robots are used as autonomous agents to reduce human labor costs, medical robots, at least to date, have been developed to add value in other application-dependent ways. For example, all the benefits mentioned in the preceding paragraph arise in laparoscopic surgery except for reduced radiation exposure, which applies to cardiac catheterization procedures. In therapeutic rehabilitation, it can be argued that the value currently added is in providing a larger number of repetitions rather than in improving the quality of the repetitions. On the other hand, energy-delivery robots, e.g., for radiotherapy, provide a combination of precision, repeatability, and speed that is hard to match by other means. Similarly, a powered prosthesis can directly improve patient outcomes by expanding both the number and quality of daily living tasks that can be performed compared with a nonrobotic device. Capsule robots may eventually replace some open bowel procedures, improving the diagnostic possibilities in hard-to-reach body regions and reducing the discomfort of existing endoluminal bowel procedures. In directing robotic technology research to maximize value added, the most important technology targets are those that will enable new types of interventions that are either currently impossible or impractical based on current technology. Magnetic actuation is an example of a technology that is enabling for capsule robots and medical microrobots. This technique has allowed miniaturization by moving actuation and power supplies outside the body. Soft robotics is likely to be a very important enabling technology over the next decade. Much of the most promising work is currently being performed in the materials community and relates to the creation of thin polymer layers with embedded sensors and actuators. Although this work seems far from medical application now, these capabilities will likely have a large influence on interventional, rehabilitative, and assistive robots. Other enabling technologies in sensing, imaging, actuation, and energy storage may arise as crossovers from consumer electronics. As an alternative to enabling new procedures, a technology can have a major influence if it provides a new way for a medical robot Downloaded from https://www.science.org on November 16, 2021 Dupont et al., Sci. Robot. 6, eabi8017 (2021) 10 November 2021 SCIENCE ROBOTICS | REVIEW 12 of 15 to add value. The effective synergy of preoperative and intraoperative imaging integrated with flexible, ergonomically enhanced surgical tools is an important example of this approach, which