Electrosurgery is now becoming universally accepted as the technique of choice in most minimally invasive surgical (MIS) procedures for achieving a variety of tissue effects ranging from dissection to hemostasis (control of bleeding) using high frequency electrical energy. However, there exists no standardized curriculum or training regimen outside the operating room (OR), for the surgical community to safely and effectively use the complex electrosurgical instruments. It is anticipated that a virtual reality (VR)-based trainer, with visual and haptic (touch) feedback, will be invaluable for electrosurgical skill training, allowing the trainees to attain competence in a controlled environment.
Major technological hurdles must be overcome, including (1) realistic physics-based modeling of the complex bio- physics of tissue cutting, hemostasis and tissue joining; (2) physical in vivo experiments to determine tissue parameters and support modeling and validation; and (3) novel realistic VR interfaces. The goal of this project is to overcome these technological barriers and design, develop and evaluate the first Virtual Electrosurgical Skill Trainer (VEST). The goal of this research is to develop and validate a comprehensive computer-based technology that will allow surgical trainees to practice their surgical skills on computer-based models. Surgical procedures and techniques, learnt and perfected in this risk-free manner before application to patients, will translate to fewer operating room errors, reduced patient morbidity and improved patient outcomes resulting in faster healing, shorter hospital stay and reduced post surgical complications and treatment costs.
VEST is composed of 5 modules:
Module 1: Tissue effects
Module 1 presents the differences between cutting and coagulating waveforms provided by the electrosurgical generator at different power levels. The simulator enables the user to see the effects on the tissue in real time as they follow the directions that highlight proper techniques and undesired effects.
Module 2: Direct and capacitive coupling
The path that the current takes when traveling from the electrical generator to the body and back can have sections where the terminals are not necessarily touching each other. There can be electrical conduction of current even in the presence of this gap as the gap forms an electrical capacitor that may allow large alternating currents to go through. Capacitive coupling happens when there is energy transfer between elements that appear disconnected but due to their instantaneous position fall into a configuration that permits energy to be transferred.
This module presents scenarios where there is capacity coupling between active and passive tools in a SILS scenario. Since capacitive coupling happens when the gaps between the tools are small, the simulator inmerses the user inside the operating cavity so that these small distances can be greatly enlarged.
Module 3: Bipolar tools
Advanced bipolar tools are the safest in their class, as the electrical generator also contains safety mechanisms to control the power level and provide feedback as to the level of tissue resistance. Nonetheless, it is possible to use these tools incorrectly and produce unintended damage. This module presents a scenario where the user has to seal and dissect the short gastric vessels while taking into account the safety guidelines for the bipolar tool without audible feedback from the electric generator. Damage to organs can happen via lateral thermal spread or out of the loop currents. This module presents an scenario where the user is required to seal and cut the short gastric vessels as part of a laparoscopic sleeve gastrectomy.
Module 4: Currents within the human body and placement of the dispersive electrode
Currents traveling within the human body between the electrodes do not travel as in a wire; instead,as the whole body is a conductor, the currents try to spread as much as possible with the constraints that it has to start and end at the electrodes. This simulator shows the path of the current when using an active electrode and a dispersive electrode. The Path of the current is shown as the active electrode is moved within the body and reacts accordingly when a new dispersive electrode is selected from the multiple options presented.
Module 5: OR fire training
This module presents a virtual operating room fire scenario and comprises two sections. In the first one, the user is guided in identifying the elements of the operating room that for part of the fire triangle (heat, fuel and oxidizing agent). The second part the user is guided by the simulation to contain a fire, following the established procedures for this emergency situation.