An External Force Sensing System for Minimally Invasive Robotic Surgery

Minimally invasive robotic surgery (MIRS) has revolutionized surgical procedures. However, compared to classic laparoscopy, the surgeon must rely only on visual perception because of the lack of force feedback. In this article, a new noninvasive force feedback system is proposed and evaluated. Extending the work by Fontanelli (2017), where preliminary results were presented, a solution based on a novel force sensor placed in the terminal part of the trocar is shown in detail. With respect to the state of the art, our system allows measuring the interaction forces between the surgical instrument and the environment inside the patient's body without any changes to the instrument structure and with full adaptability to different robotic platforms and surgical tools. Using a commercial force-torque sensor as ground truth, the static and dynamic characterization of the sensor is provided together with an extensive experimental validation. Finally, a simple and intuitive application of the proposed sensing system in a realistic surgical scenario is presented.