Virtual interactive suturing for the Fundamentals of Laparoscopic Surgery (FLS)

Split & Join: An Efficient Approach for Simulating Stapled Intestinal Anastomosis in Virtual Reality

Colorectal cancer is a life-threatening disease. It is the second leading cause of cancer-related deaths in the United States. Stapled anastomosis is a rapid treatment for colorectal cancer and other intestinal diseases and has become an integral part of routine surgical practice. However, to the best of our knowledge, there is no existing work simulating intestinal anastomosis that often involves sophisticated soft tissue manipulations such as cutting and stitching. In this paper, for the first time, we propose a novel split and join approach to simulate a side-to-side stapled intestinal anastomosis in virtual reality. We mimic the intestine model using a new hybrid representation - a grid-linked particles model for physics simulation and a surface mesh for rendering. The proposed split and join operations handle the updates of both the grid-linked particles model and the surface mesh during the anastomosis procedure. The simulation results demonstrate the feasibility of the proposed approach in simulating intestine models and the side-to-side anastomosis operation.

Visual Haptic Feedback for Training of Robotic Suturing

Current surgical robotic systems are teleoperated and do not have force feedback. Considerable practice is required to learn how to use visual input such as tissue deformation upon contact as a substitute for tactile sense. Thus, unnecessarily high forces are observed in novices, prior to specific robotic training, and visual force feedback studies demonstrated reduction of applied forces. Simulation exercises with realistic suturing tasks can provide training outside the operating room. This paper presents contributions to realistic interactive suture simulation for training of suturing and knot-tying tasks commonly used in robotically-assisted surgery. To improve the realism of the simulation, we developed a global coordinate wire model with a new constraint development for the elongation. We demonstrated that a continuous modeling of the contacts avoids instabilities during knot tightening. Visual cues are additionally provided, based on the computation of mechanical forces or constraints, to support learning how to dose the forces. The results are integrated into a powerful system-agnostic simulator, and the comparison with equivalent tasks performed with the da Vinci Xi system confirms its realism.

Mapping the intellectual structure of research on surgery with mixed reality: Bibliometric network analysis (2000-2019)

OBJECTIVE

The purpose of this study is to view research trends on surgery with mixed reality, and present the intellectual structure using bibliometric network analysis for the period 2000-2019.

METHODS

Analyses are implemented in the following four steps: (1) literature dataset acquisition from article database (Web of Science, Scopus, PubMed, and IEEE digital library), (2) dataset pre-processing and refinement, (3) network construction and visualization, and (4) analysis and interpretation. Descriptive analysis, bibliometric network analysis, and in-depth qualitative analysis were conducted.

RESULTS

The 14,591 keywords of 5897 abstracts data were ultimately used to ascertain the intellectual structure of research on surgery with mixed reality. The dynamics of the evolution of keywords in the structure throughout the four periods is summarized with four aspects: (a) maintaining a predominant utilization tool for training, (b) widening clinical application area, (c) reallocating the continuum of mixed reality, and (d) steering advanced imaging and simulation technology.

CONCLUSIONS

The results of this study can provide valuable insights into technology adoption and research trends of mixed reality in surgery. These findings can help clinicians to overview prospective medical research on surgery using mixed reality. Hospitals can also understand the periodical maturity of technology of mixed reality in surgery, and, therefore, these findings can suggest an academic landscape to make a decision in adopting new technologies in surgery.

Validation of a Novel Needle Holder to Train Advanced Laparoscopy Skills to Novices in a Simulator Environment

Background. Our aim was to determine if a newly designed Najar needle holder (NNH) shortens the time for novices to improve advanced laparoscopy (AL) techniques (suturing/knot tying), compared with a conventional macro needle holder (MNH) in a simulator. Furthermore, we aimed to validate a new video scoring system determining AL skills. Methods. Forty-six medical students performed identical surgical tasks in a prospective, crossover study evaluating AL skills (NNH vs MNH). All subjects performed a double-throw knot, 2 single-throw knots following 3 running sutures in the Simball Box (SB) simulator. After resting, subjects switched needle holders. All tasks were videotaped and analyzed using SB software and by 2 independent reviewers using the Objective Video Evaluation Scoring Table (OVEST). Trial performance expressed as SB Overall Score (SBOS) and OVEST. Results. In the group starting with NNH (followed by MNH) OVEST was consistently high during both trials (median = 12.5, range = 6.5-18.0, and median = 13.5, range = 6.5-21.0; P = .2360). However, in the group starting with MNH, OVEST improved significantly when the participants changed to NNH (median = 10.0, range = 2.5-19.5, vs median = 14.5, range = 4.5-18.0; P = .0003); an improvement was also found with SBOS (median = 37%, range = 27% to 92%, vs median = 48%, range = 34% to 70%; P = .0289). In both trials, both independent reviewers' OVEST measures correlated well: Trial 1: β = 0.97, P < .0001; and Trial 2: β = 0.95, P < .0001. A correlation also existed between SBOS and OVEST in both trials (β = 2.1, P < .0001; and β = 1.9, P = .0002). Conclusions. This study indicates a significantly higher improvement in laparoscopic suturing skills in novices training AL skills using NNH compared with MNH. Starting early, AL training in novices using NNH is a feasible option. Furthermore, OVEST used in experimental settings as an evaluation tool is comparable with the validated SBOS.

Reference tool kinematics-kinetics and tissue surface strain data during fundamental surgical acts

Haptic based surgical simulations are popular training aids in medicine. Previously, surgical tool loads and motion were measured during cutting and needle insertion on non-human tissue and several haptic based simulations were developed to enhance surgical training. However, there was a lack of realistic foundational data regarding the mechanical responses of human tissue and tools during fundamental acts of surgery, i.e., cutting, suturing, retracting, pinching and indenting. This study used four recently developed surgical tools in a variety of procedures on a diverse set of cadaver leg specimens from human donors. The kinematics and kinetics of surgical tools were recorded along with topical three-dimensional strain during commonly performed surgical procedures. Full motion and load signatures of foundational surgical acts can also be used beyond the development of authentic visual and haptic simulations of surgery, i.e., they provide mechanical specifications for the development of autonomous surgical systems.

Characterizing the learning curve of a virtual intracorporeal suturing simulator VBLaST-SS©

BACKGROUND

The virtual basic laparoscopic skill trainer suturing simulator (VBLaST-SS©) was developed to simulate the intracorporeal suturing task in the FLS program. The purpose of this study was to evaluate the training effectiveness and participants' learning curves on the VBLaST-SS© and to assess whether the skills were retained after 2 weeks without training.

METHODS

Fourteen medical students participated in the study. Participants were randomly assigned to two training groups (7 per group): VBLaST-SS© or FLS, based on the modality of training. Participants practiced on their assigned system for one session (30 min or up to ten repetitions) a day, 5 days a week for three consecutive weeks. Their baseline, post-test, and retention (after 2 weeks) performance were also analyzed. Participants' performance scores were calculated based on the original FLS scoring system. The cumulative summation (CUSUM) method was used to evaluate learning. Two-way mixed factorial ANOVA was used to compare the effects of group, time point (baseline, post-test, and retention), and their interaction on performance.

RESULTS

Six out of seven participants in each group reached the predefined proficiency level after 7 days of training. Participants' performance improved significantly (p < 0.001) after training within their assigned group. The CUSUM learning curve shows that one participant in each group achieved 5% failure rate by the end of the training period. Twelve out of fourteen participants' CUSUM curves showed a negative trend toward achieving the 5% failure rate after further training.

CONCLUSION

The VBLaST-SS© is effective in training laparoscopic suturing skill. Participants' performance of intracorporeal suturing was significantly improved after training on both systems and was retained after 2 weeks of no training.

Validation of a virtual intracorporeal suturing simulator

BACKGROUND

Intracorporeal suturing is one of the most important and difficult procedures in laparoscopic surgery. Practicing on a FLS trainer box is effective but requires large number of consumables, and the scoring is somewhat subjective and not immediate. A virtualbasic laparoscopic skill trainer (VBLaST©) was developed to simulate the five tasks of the FLS Trainer Box. The purpose of this study is to evaluate the face and content validity of the VBLaST suturing simulator (VBLaST-SS©).

METHODS

Twenty-five medical students and residents completed an evaluation of the simulator. The participants were asked to perform the standard intracorporeal suturing task on both VBLaST-SS© and the traditional FLS box trainer. The performance scores on each system were calculated based on time (s), deviations to the black dots (mm), and incision gap (mm). The participants were then asked to finish a 13-item questionnaire with ratings from 1 (not realistic/useful) to 5 (very realistic/useful) regarding the face validity of the simulator. A Wilcoxon signed rank test was performed to identify differences in performance on the VBLaST-SS© compared to that of the traditional FLS box trainer.

RESULTS

Three questions from the face validity questionnaire were excluded due to lack of response. Ratings to 8 of the remaining 10 questions (80%) averaged above 3.0 out of 5. Average intracorporeal suturing completion time on the VBLaST-SS© was 421 (SD = 168 s) seconds compared to 406 (175 s) seconds on the box trainer (p = 0.620). There was a significant difference between systems for the incision gap (p = 0.048). Deviation in needle insertion from the black dot was smaller for the box trainer than the virtual simulator (1.68 vs. 7.12, p < 0.001).

CONCLUSION

Participants showed comparable performance on the VBLaST-SS© and traditional box trainer. Overall, the VBLaST-SS© system showed face validity and has the potential to support training for the suturing skills.

Development and face validation of a virtual camera navigation task trainer

BACKGROUND

The fundamentals of laparoscopic surgery (FLS) trainer box, which is now established as a standard for evaluating minimally invasive surgical skills, consists of five tasks: peg transfer, pattern cutting, ligation, intra- and extracorporeal suturing. Virtual simulators of these tasks have been developed and validated as part of the Virtual Basic Laparoscopic Skill Trainer (VBLaST) (Arikatla et al. in Int J Med Robot Comput Assist Surg 10:344-355, 2014; Zhang et al. in Surg Endosc 27(10):3603-3615, 2013; Sankaranarayanan et al. in J Laparoendosc Adv Surg Tech 20(2):153-157, 2010; Qi et al. J Biomed Inform 75:48-62, 2017). The virtual task trainers have many advantages including automatic real-time objective scoring, reduced costs, and eliminating human proctors. In this paper, we extend VBLaST by adding two camera navigation system tasks: (a) pattern matching and (b) path tracing.

METHODS

A comprehensive camera navigation simulator with two virtual tasks, simplified and cheaper hardware interface (compared to the prior version of VBLaST), graphical user interface, and automated metrics has been designed and developed. Face validity of the system is tested with medical students and residents from the University at Buffalo's medical school.

RESULTS

The subjects rated the simulator highly in all aspects including its usefulness in training to center the target and to teach sizing skills. The quality and usefulness of the force feedback scored the lowest at 2.62.