There has been a steep continuous progress and development in the field of surgical robots, where they are becoming more specialized and integrated to meet the ever-growing list of clinical needs. There are at least 50 surgical robots across all surgical specialties in various stages of development or availability on the market. Given the number and diversity of surgical robots in public discourse, we propose what is, to our knowledge, the first surgical robot classification to better categorize these diverse systems. This will help individuals in the clinical and medical technology fields better understand systems, communicate more clearly about the established potential of robotic surgery, and identify ongoing needs. The goal would be to establish this classification in the field of robotic surgery, and we plan to continue to add and expand to it as we navigate new and emerging breakthrough technologies.

We aimed to develop a universal and generalizable classification to categorize surgical robotic systems based on recognizing and classifying shared traits among these systems. This classification was created in a repeatable, guideline-based fashion that was suited to this task using the NISO framework applicable to fields outside healthcare or biology [7]. These methods are similar to other methods of classification creation that have been published in healthcare literature [6].

We chose to follow this repeatable methodology of creating a classification with the intent of maintaining as much objectivity as possible in the result. However, even a committee is subject to biases and conflicts. For instance, although 2 engineers were on the classification committee, the classification of devices proposed here is largely designed as a description of robotic architecture from a surgeon’s perspective. When considering the features that are included into this classification scheme, the committee focused on the end-effector that interacts with the patient. Similarly, classification of the patient cart was prioritized over the surgeon console. One conflict that appeared in our committee process was whether to include a classification of patient entry approach, whether being via a natural orifice such as endoscopy or via an incision. The committee chose an agnostic approach of not including this distinction, as flexible endoscopes can be inserted through incisional trocars, and similarly, rigid robotic devices can operate within the oral or anal cavities.

While we attempted to keep these categorizations as binary as possible, there are certain systems that defy some of the strict definitions, and it would be nearly impossible to account for these discrete variations in detail in what we aimed to be a widely generalizable classification. For example, when discussing rigid and flexible sheaths it is notable that certain systems have rigid sheaths but flexible and articulating end effectors (example: Vicarious), while others have purely rigid sheaths up to the level of the instrument’s wrist (example: MMI’s Symani). These classifications have been previously established, and if some devices have both flexible and rigid characteristics, we would categorize the device with a majority vote [22]. Regarding the number of patient ports, this categorization describes the most common use. That said, some systems may have a single trocar and multiple working arms (example: Intuitive da Vinci SP), and others may have multiple trocars and working arms (example: Medtronic Hugo). Additionally, some systems may have multiple trocars entering the body cavity through the same incision, by the use of a gel port for example, whereas others require individual incisions for each trocar.

In regard to creating a complete list of soft tissue surgical robots, it is important to note that the information presented here is entirely based on the information that is publicly available, either through the FDA database, national and international conferences, company websites, and PubMed. It does not include device applications that are pending approval, as this is not public information. It is likely that there are several other systems not captured here as they may have not yet publicized their work or may be in the germinal phase of research and development, among other reasons. We also note that our search for surgical robotic devices did not include the Chinese National Medical Products Administration as this body does not have a publicly searchable database of approved products. It also does not include Korean MFDS-approved devices predating 2014, as this information is not publicly available on their website.

Despite the limitations aforementioned, our review of surgical systems proposes a classification scale for identifying current and emerging surgical robotic technologies. Notably, this categorization is very contemporary and will be outdated as new technologies emerge. As surgical robotics evolves over time, this nomenclature will likely need to adapt and grow along with the technology it describes.

The standardized common language and classification presented here could be useful to several groups of users. Surgeons and proceduralists need a framework to understand the large variety of robotic-assisted surgical devices and what procedures each may be of best use. Healthcare administrators need this information to plan budgets, grow and manage practices, and monitor patient quality outcomes. Such classification would be of particular use when outfitting operating rooms and deciding which robotic devices best suit their practice in accounting for caseloads. Engineers can use this classification to better understand the device design from the clinical perspective of a healthcare provider. This would also allow engineers to better identify and address unmet needs in the industry. Surgical educators need to understand the organization of these devices to keep up with the development of the technology as they train future surgeons. Regulatory agencies could benefit from adopting a common language to keep up with future innovations. Surgical societies, by creating guidelines, holding meetings, and publishing research, can standardize language on surgery-related topics. Adopting this common language would facilitate communication about robotic surgery and allow community members to keep current on the practice of evidence dissemination regarding surgical robotics and innovation. This multidisciplinary communication and collaboration will only help further education and development in robotic surgery.