Assistive Technology for enhanced execution of Sacrocolpopexy

Surgery is an essential part of health care that helps millions of people lead healthier, more productive lives. In the early years, access to the patient's internal anatomy was mostly achieved by means of a large incision. This led to several complications such as excessive bleeding, increased chances of infection and consequentially high mortality rates after surgery. To address these issues many disciplines transitioned to minimally invasive surgery (MIS), a technique that employs long and slender instruments inserted through small keyhole incisions. Today, a commonly performed keyhole intervention is the repair of pelvic organ prolapse (POP) by means of laparoscopic sacrocolpopexy (LSC). With this approach, various keyhole incisions in the abdominal wall allow to operate with minimal amounts of patient harm. This results in better operative outcomes such as reduced blood loss and a faster hospital discharge. Nonetheless, constraining the instruments to pivot about the keyhole incisions severely limits the surgeon's dexterity. Furthermore, LSC requires two assistants: The first assistant operates a laparoscope to visualize the patient's internals; while the second assistant positions and tensions the vaginal vault such that the main surgeon can apply a synthetic mesh to restore the prolapse. Providing instrument assistance for long periods of time is strenuous as a result of the non-ergonomic operating conditions imposed by the keyholes. In addition, the vaginal vault tensioning forces are high, which further complicates the task.

To alleviate the assistants from their poor working conditions, surgeons and engineers have combined efforts to develop robotic systems that allow for solo laparoscopic surgery. In this scenario, the solo surgeon is assisted by one or more robotic devices that provide him/her with full control over all instruments involved. However, the current robotic surgery market is dominated by telesurgery systems that require the solo surgeon to operate through a distally placed main console. Such systems are expensive, reduce situational awareness and inhibit the solo surgeon from exercising his/her high levels of skill.

To tackle the disadvantages imposed by telesurgery systems, this work aims to develop a robotic platform for synergistic solo LSC. In a synergistic robot-assisted surgery scenario, the solo surgeon manually performs tasks that take advantage from his/her high level of skill while a plurality of robots relieve the human assistants from their strenuous working conditions.

The first part of this dissertation provides a thorough analysis of laparoscope and vaginal manipulator operation during LSC surgery. Laparoscopic assistance is analyzed from literature, attending surgery and interviews with gynecologists. Vaginal manipulation, in contrast, is scarcely documented in literature. Therefore, an in vivo clinical study is conducted as part of this work which uses a custom designed force sensor to measure vaginal vault tensioning forces and the instrument's working volume during LSC surgery. After this analysis an initial set of design requirements for a synergistic solo LSC platform is formulated.

Thereafter, a base configuration of the robotic platform is developed that incorporates the first set of design requirements. To this aim, a modular comanipulation control scheme is introduced that flexibly allows to extend the platform with robotic devices and adapt their functionality. Further, two registration methods and an end effector pose improvement algorithm are introduced to provide adequate levels of inter-robot awareness.

Next, the platform is extended with virtual pointer functionality. By using the laparoscope as a virtual pointer, the solo surgeon is able to direct the vaginal manipulator to provide proper vault exposure. The platform configuration is experimentally validated by 10 gynecologists on a box trainer. Outcomes demonstrate that synergistic robotic assistance allows the surgeon to complete LSC mesh fixation as solo surgery. The results of this first round of experimental validation are used to iterate on the platform's design requirements.

Lastly, a second platform configuration is developed which provides multimodal instrument interaction. With multimodality, a plurality of instrument interaction modes is available to operate a single instrument. It allows the solo surgeon to take advantage of their individual benefits best suited to the phase of surgery. Further, it omits the need for human assistance when a single interaction mode does not cover the wide space of surgical tasks. A second round of experimental validation by means of mesh fixation is performed with the robotic platform. The results are promising as the solo surgeons were able to reduce task time and better control tensioning forces applied to the vaginal vault. A second iteration of the platform's design requirements is provided at the end of this validation round.

This doctoral work concludes that synergistic solo laparoscopy opens the path towards a familiar way of operating with small learning curves, increased situational awareness and consequentially improved patient safety.