Visual force feedback in laparoscopic training

Abstract

BackgroundTo improve endoscopic surgical skills, an increasing number of surgical residents practice on box or virtual reality (VR) trainers. Current training is focused mainly on hand–eye coordination. Training methods that focus on applying the right amount of force are not yet available.MethodsThe aim of this project is to develop a low-cost training system that measures the interaction force between tissue and instruments and displays a visual representation of the applied forces inside the camera image. This visual representation continuously informs the subject about the magnitude and the direction of applied forces. To show the potential of the developed training system, a pilot study was conducted in which six novices performed a needle-driving task in a box trainer with visual feedback of the force, and six novices performed the same task without visual feedback of the force. All subjects performed the training task five times and were subsequently tested in a post-test without visual feedback.ResultsThe subjects who received visual feedback during training exerted on average 1.3 N (STD 0.6 N) to drive the needle through the tissue during the post-test. This value was considerably higher for the group that received no feedback (2.6 N, STD 0.9 N). The maximum interaction force during the post-test was noticeably lower for the feedback group (4.1 N, STD 1.1 N) compared with that of the control group (8.0 N, STD 3.3 N).ConclusionsThe force-sensing training system provides us with the unique possibility to objectively assess tissue-handling skills in a laboratory setting. The real-time visualization of applied forces during training may facilitate acquisition of tissue-handling skills in complex laparoscopic tasks and could stimulate proficiency gain curves of trainees. However, larger randomized trials that also include other tasks are necessary to determine whether training with visual feedback about forces reduces the interaction force during laparoscopic surgery.

Force-Sensing Enhanced Simulation Environment (ForSense) for laparoscopic surgery training and assessment

“…Although the literature is generally scarce in this field, the group from the Delft University of Technology showed a tendency to favor mean absolute nonzero force. 20,21 In comparing multiple variables of force, we found that the difference in mean force among experience groups was less important than other variables investigated. We hypothesize that this is owing to bias introduced by increased time that nonexperts spend in the ''idle'' state that brings down any central tendency value.…”

Influence of visual force feedback on tissue handling in minimally invasive surgery

“…As needle‐driving in this study was only a part of the total task, it seems that trainees were satisfied when the needle had been driven through the tissue successfully and then focused on the more complex knot‐tying part of the task. Because the complete suture task requires a larger cognitive component than the needle‐driving task alone, it is likely that a greater focus on forces exerted on the needle during the short needle‐driving phase results in a greater reduction in force, as shown previously. This suggests that complex tasks should be divided into smaller, simpler tasks, which are trained individually to create optimal learning circumstances.…”

“…This included a force sensor to measure time and force in laparoscopic box trainers ranging from 0 to 10 N in three dimensions, with an accuracy of 0·1 N and a measurement frequency of 60 Hz. A webcam was used to capture images of the work space of the instruments. A box trainer illuminated to simulate laparoscopic surgery was equipped with two trocars and two needle drivers (Ethicon E705R 5 mm; Johnson & Johnson, Norderstedt, Germany).…”

Improving training of laparoscopic tissue manipulation skills using various visual force feedback types

“…The ForMoST hybrid trainer is equipped with the TrEndo tracking system, the ForceTRAP force tracking system and an USB camera for the visualization of the task on the computer screen [18]. The ForMoST system measures all instrument movement and forces exerted on the training task.…”