Image guided interpedicular screw placement simulation system for training and skill evaluation. Proof of concept.

INTRODUCTION: Present work introduces SpineST-01 system, an image guided vertebrae cannulation training system. During task execution, the computer calculates performance based metrics displaying different visual perspectives (LV, AV, APV) with the position of the instrument inside it. Finally, a report with the metrics is generated as performance feedback. METHODS: A training box holds a 3D printed spine section. The computer works with two orthogonal disposed cameras, tracking passive markers placed on the instrument. Eight metrics were proposed to evaluate the surgical task's execution performance. A preliminary study, with 25 participants divided into three groups: 12 Novices, 10 intermediates and 3 Experts, was conducted to determine the feasibility of the system to evaluate and assess the performance differences of each group using Kruskal-Wallis analysis and U Mann-Whitney. In both, Kruskal-Wallis analysis and U Mann-Whitney, a p-value ≤0.05 was considered statistically significant. RESULTS: When comparing Experts vs Novices and the three groups, the statistical analysis showed significant differences in six of the eight metrics. (Axial angle error (°), Lateral angle error (°), Average Speed (mm/s), Progress between shots (mm), Time (s), Shots) The metrics that did not show any statistically significant difference were time between shots (s), and speed between shots (mm/s). As well the average result comparison placed the Experts as the best performance group. CONCLUSION: On the SpineST-01 presentation, initial testing demonstrated potential for the system to practice image guided cannulation task on lumbar vertebrae. Results show objective differences between Experts, Intermediates, and Novices on the proposed metrics. Making this system a feasible option for developing basic navigation system skills, without the risk of radiation exposure and objectively evaluate task performance.

Novices' learning curve in single-port surgery using three surgical training programs.

BACKGROUND: The objective of this study was to evaluate the novices' learning curves and proficiency level reached in laparoendoscopic single-site (LESS) surgery using three surgical training programs. MATERIAL AND METHODS: Participants were randomly divided into three groups, who trained in a specific practice regimen for 12 days using a laparoscopic box simulator and three tasks. Group A trained in three stages using conventional laparoscopic surgery (CLS) with straight instruments, and LESS with straight and articulating instruments for four days each. Group B trained in two stages in LESS with straight and articulating instruments for six days each. Group C trained only in LESS with articulating instruments exclusively for all 12 days. Performance was registered daily during the 12 days to evaluate the participants' progress. RESULTS: Pre- and post-training analysis of the three groups showed significant differences in performance, denoting the significant improvement in their LESS skills, with no difference between the groups. Group C reached a high level of technical competence with their specific training program in LESS, obtaining a lower asymptote and slow learning rate. CONCLUSION: Specific training programs in LESS settings using articulated instruments showed a slower learning rate than the other programs but better proficiency in the technique with the best surgical performance.

Objective Evaluation of Laparoscopic Experience Based on Muscle Electromyography and Accelerometry Performing Circular Pattern Cutting Tasks: A Pilot Study.

Purpose.The aim of this work is to present a new physical laparoscopy simulator with an electromyography (EMG)/accelerometry-based muscle activity recording system, EvalLap EMG-ACC, and perform objective evaluation of laparoscopic skills based on the quantification of muscle activity of participants with different levels of laparoscopic experience. Methods. EMG and ACC signals were obtained from 14 participants (6 experts, 8 medical students) performing circular pattern cutting tasks using a laparoscopic box trainer with the Trigno (Delsys Inc, Natick, MA) portable wireless system of 16 wireless sensors. Sensors were placed on the proximal and distal muscles of the upper extremities. Seven evaluation metrics were proposed and compared between skilled and novice surgeons. Results. The proximal and distal arm muscles (trapezius, deltoids, biceps, and forearms) were most active while executing laparoscopic tasks. Laparoscopic experience was associated with differences in EMG amplitude (Aavg), muscle activity (iEMG), hand acceleration (iACH), user movement (iAC), and muscle fatigue. For the cutting task, the deltoid, bicep, forearm EMG amplitude, and user movement significantly differed between experience groups. Conclusion. This pilot study demonstrates that different muscle groups are preferentially activated during laparoscopic tasks depending on the level of surgical experience. Expert surgeons showed less muscle activity compared with novices. EvalLap EMG-ACC represents a promising means to distinguish surgeons with basic cutting skills from those who have not yet developed these skills.

Steerable Surgical Instrument for Conventional and Single-Site Minimally Invasive Surgery.

Background. This article aims to present an innovative design of a steerable surgical instrument for conventional and single-site minimally invasive surgery (MIS), which improves the dexterity and maneuverability of the surgeon while offering a solution to the limitations of current tools. Methods. The steerable MIS instrument consists of a deflection structure with a curved sliding joints design that articulates the distal tip in two additional degrees of freedom (DoFs), relative to the instrument shaft, using transmission by cables. A passive ball-joint mechanism articulates the handle relative to the instrument shaft, improves wrist posture, and prevents collision of instrument handles during single-site MIS procedures. The two additional DoFs of the articulating tip are activated by a thumb-controlled device, using a joystick design mounted on the handle. This steerable MIS instrument was developed by additive manufacturing in a 3D printer using PLA polymer. Results. Prototype testing showed a maximum tip deflection of 60° in the left and right directions, with a total deflection of 120°. With the passive ball-joint fully offset, the steerable tip achieved a deflection of 90° for the right and 40° for the left direction, with a total deflection of 130°. Furthermore, the passive ball-joint mechanism in the handle obtained a maximum range of motion of 60°. Conclusions. This steerable MIS instrument concept offers an alternative to enhance the application fields of conventional and single-site MIS, increasing manual dexterity of the surgeon and the ability to reach narrow anatomies from other directions.

Integration of Comprehensive Metrics into the PsT1 Neuroendoscopic Training System.

OBJECTIVE: Metric-based surgical training can be used to quantify the level and progression of neurosurgical performance to optimize and monitor training progress. Here we applied innovative metrics to a physical neurosurgery trainer to explore whether these metrics differentiate between different levels of experience across different tasks. METHODS: Twenty-four participants (9 experts, 15 novices) performed 4 tasks (dissection, spatial adaptation, depth adaptation, and the A-B-A task) using the PsT1 training system. Four performance metrics (collision, precision, dissected area, and time) and 6 kinematic metrics (dispersion, path length, depth perception, velocity, acceleration, and motion smoothness) were collected. RESULTS: For all tasks, the execution time (t) of the experts was significantly lower than that of novices (P < 0.05). The experts performed significantly better in all but 2 of the other metrics, dispersion and sectional area, corresponding to the A-B-A task and dissection task, respectively, for which they showed a nonsignificant trend towards better performance (P = 0.052 and P = 0.076, respectively). CONCLUSIONS: It is possible to differentiate between the skill levels of novices and experts according to parameters derived from the PsT1 platform, paving the way for the quantitative assessment of training progress using this system. During the current coronavirus disease 2019 pandemic, neurosurgical simulators that gather surgical performance metrics offer a solution to the educational needs of residents.

Objective classification of psychomotor laparoscopic skills of surgeons based on three different approaches.

BACKGROUND: The determination of surgeons' psychomotor skills in minimally invasive surgery techniques is one of the major concerns of the programs of surgical training in several hospitals. Therefore, it is important to assess and classify objectively the level of experience of surgeons and residents during their training process. The aim of this study was to investigate three classification methods for establishing automatically the level of surgical competence of the surgeons based on their psychomotor laparoscopic skills. METHODS: A total of 43 participants, divided into an experienced surgeons group with ten experts (> 100 laparoscopic procedures performed) and non-experienced surgeons group with 24 residents and nine medical students (< 10 laparoscopic procedures performed), performed three tasks in the EndoViS training system. Motion data of the instruments were captured with a video-tracking system built into the EndoViS simulator and analyzed using 13 motion analysis parameters (MAPs). Radial basis function networks (RBFNets), K-star (K*), and random forest (RF) were used for classifying surgeons based on the MAPs' scores of all participants. The performance of the three classifiers was examined using hold-out and leave-one-out validation techniques. RESULTS: For all three tasks, the K-star method was superior in terms of accuracy and AUC in both validation techniques. The mean accuracy of the classifiers was 93.33% for K-star, 87.58% for RBFNets, and 84.85% for RF in hold-out validation, and 91.47% for K-star, 89.92% for RBFNets, and 83.72% for RF in leave-one-out cross-validation. CONCLUSIONS: The three proposed methods demonstrated high performance in the classification of laparoscopic surgeons, according to their level of psychomotor skills. Together with motion analysis and three laparoscopic tasks of the Fundamental Laparoscopic Surgery Program, these classifiers provide a means for objectively classifying surgical competence of the surgeons for existing laparoscopic box trainers.

A Low-Cost, Passive Navigation Training System for Image-Guided Spinal Intervention.

BACKGROUND: Navigation technology is used for training in various medical specialties, not least image-guided spinal interventions. Navigation practice is an important educational component that allows residents to understand how surgical instruments interact with complex anatomy and to learn basic surgical skills such as the tridimensional mental interpretation of bidimensional data. Inexpensive surgical simulators for spinal surgery, however, are lacking. We therefore designed a low-cost spinal surgery simulator (Spine MovDigSys 01) to allow 3-dimensional navigation via 2-dimensional images without altering or limiting the surgeon's natural movement. METHODS: A training system was developed with an anatomical lumbar model and 2 webcams to passively digitize surgical instruments under MATLAB software control. A proof-of-concept recognition task (vertebral body cannulation) and a pilot test of the system with 12 neuro- and orthopedic surgeons were performed to obtain feedback on the system. Position, orientation, and kinematic variables were determined and the lateral, posteroanterior, and anteroposterior views obtained. RESULTS: The system was tested with a proof-of-concept experimental task. Operator metrics including time of execution (t), intracorporeal length (d), insertion angle (α), average speed (v¯), and acceleration (a) were obtained accurately. These metrics were converted into assessment metrics such as smoothness of operation and linearity of insertion. Results from initial testing are shown and the system advantages and disadvantages described. CONCLUSIONS: This low-cost spinal surgery training system digitized the position and orientation of the instruments and allowed image-guided navigation, the generation of metrics, and graphic recording of the instrumental route. Spine MovDigSys 01 is useful for development of basic, noninnate skills and allows the novice apprentice to quickly and economically move beyond the basics.

Construct validity of a video-tracking system based on orthogonal cameras approach for objective assessment of laparoscopic skills.

PURPOSE: This study was aimed to establish the construct validity of a video-tracking system based on orthogonal cameras approach for assessment of laparoscopic psychomotor skills in training environments. METHODS: The camera-tracking system consists of two webcams placed in orthogonal configuration at a distance of 13.5 cm. The orthogonal cameras employ a color segmentation algorithm to register the 3D motions of the laparoscopic instruments using colored tapes placed on the distal end. For construct validity, 31 participants (4 experts and 27 residents) performed three training tasks in a laparoscopic box trainer with the built-in orthogonal cameras system. Eleven motion-related parameters were used to evaluate their performance. Statistical analysis was performed, and results between two groups were compared using a Mann-Whitney U-test. RESULTS: Construct validity results showed statistical differences in almost all motion-related parameters for assessment of laparoscopic technical skills. Results demonstrated that the orthogonal video-based tracking system was able to differentiate laparoscopic experience between experts and trainees surgeons. CONCLUSION: The orthogonal cameras system was successfully validated in a laparoscopic box trainer. This video-based tracking system was able to distinguish performance between experts and trainees surgeons, showing its potential as a reliable tool to assess laparoscopic psychomotor skills. The orthogonal cameras allow incorporating the advantages of this video motion-tracking technology with the benefits of the traditional laparoscopic box trainers, creating realistic haptic feedback and allowing the evaluation of psychomotor skills of the surgeons.

Pediatric inguinal hernia repair with a single-incision approach using an Endo Close™ suturing device.

BACKGROUND: Diverse techniques have been described for pediatric inguinal hernia repair, based on extraperitoneal [1-4] and intraperitoneal [5-8] methodologies. In this video, we describe a novel technique to repair pediatric inguinal hernia using an Endo Close™ suturing device by percutaneous puncture with a single incision. METHODS: With a transumbilical approach, a 5-mm trocar is inserted for a 30° laparoscope. A 3-mm incision is made, and the Endo Close™ suturing device (Covidien, Minneapolis, MN, USA), with a 2-0 polypropylene suture retained by the stylet, is inserted perpendicularly to the skin. An extraperitoneal dissection is made on a side the inguinal ring and the needle of the device penetrates the peritoneum through the inferior border. Then, the stylet mechanism is pushed to free the lasso inside the cavity. At the same incision site, the needle of the Endo Close™ is inserted again, but an extraperitoneal dissection is made on the other side of the ring, ensuring that the needle penetrates at the same exit orifice. Now, the suture lasso is recovered and retracted to close the ring. Finally, the suture is extracted and knots are tied extracorporeally at the level of the skin. RESULTS: A total of 34 patients (20 females and 14 males) underwent surgery with this procedure. Operative time for unilateral repair was 10-15 and 25-30 min for the bilateral repair (29 unilateral/5 bilateral). The patients experienced minimal postoperative pain. The follow-up period was 12 months with no complications, no recurrence and without cases of postoperative hydrocele. There were no injuries to the structures as vessels or vas deferens, and the esthetic outcome was excellent. CONCLUSIONS: The technique presents a simple, safe and reliable method to repair inguinal hernias in children. The long-term results of this novel technique will be evaluated in future studies.

Optimizing the positional relationships between instruments used in laparoscopic simulation using a simple trigonometric method.

BACKGROUND: Various methods for evaluating laparoscopic skill have been reported, but without detailed information on the configuration used they are difficult to reproduce. Here we present a method based on the trigonometric relationships between the instruments used in a laparoscopic training platform in order to provide a tool to aid in the reproducible assessment of surgical laparoscopic technique. MATERIALS AND METHODS: The positions of the instruments were represented using triangles. Basic trigonometry was used to objectively establish the distances among the working ports RL, the placement of the optical port h', and the placement of the surgical target OT. RESULTS: The optimal configuration of a training platform depends on the selected working angles, the intracorporeal/extracorporeal lengths of the instrument, and the depth of the surgical target. We demonstrate that some distances, angles, and positions of the instruments are inappropriate for satisfactory laparoscopy. CONCLUSIONS: By applying basic trigonometric principles we can determine the ideal placement of the working ports and the optics in a simple, precise, and objective way. In addition, because the method is based on parameters known to be important in both the performance and quantitative quality of laparoscopy, the results are generalizable to different training platforms and types of laparoscopic surgery.

Is the digitization of laparoscopic movement using accessible alternative technologies possible?

It is widely documented that laparoscopic surgeons require training, and an objective evaluation of the training that they receive. The most advanced evaluation systems integrate the digitization of the movement of laparoscopic tools. A great number of these systems, however, do not permit the use of real tools and their high cost limits their academic impact. Likewise, it is documented that new and accessible systems need to be developed. The aim of this article is to explore the possibility of digitizing the movement of laparoscopic tools in a three-dimensional workspace, using accessible alternative technology. Our proposal uses a commercial Wii video game control in conjunction with a program for determining kinematic variables during the execution of a recognition task.

Initial clinical experience using a novel laparoscopy assistant.

This article presents the first clinical and experimental experiences of the PMASS (Postural Mechatronic Assistance Solo Surgery) from a prospective study carried on on thirteen laparoscopic procedures. Also, their advantages and disadvantages are identified. The PMASS is a system with three articulations; two articulations are passive and one is active; this handles the optic in real time, reducing the latency time by spatial relocation. The surgeons assisted themselves visually in 13 surgical procedures, having direct and intuitive control in real time of the laparoscopic vision field using the PMASS. The surgical and delay time was documented for each surgery. The surgical procedures were: Laparoscopic appendicectomy, ovarian cystectomy and laparoscopic sterilization. In all procedures, surgeons were able to auto-navigate in real time and there was no visual tremor while using the system. The global average times taken to perform the self-assisted surgery with the PMASS for the laparoscopic appendicectomies were 45 ± 4.5 minutes, ovarian cystectomies 49 ± 3.5 minutes and for the laparoscopic sterilization 22 ± 2 minutes. The approximate set-up time of PMASS was one minute, and removal almost a minute (the time required by the surgeon to remove the harness after completing the surgery). The laparoscope itself disengages from the PMASS in a couple of seconds approximately. There were no transoperative or postoperative complications during the procedures. Thirteen laparoscopic procedures were performed, the design of the mechatronic assistance allowed the surgeon to self-assist visually in real time and in an autonomous way in the solo-surgery mode, without compromising the surgical performance and the morbidity. Additionally, the latency times are also reduced by space relocation and coupling of the telescope.

Postural mechatronic assistant for laparoscopic solo surgery (PMASS).

BACKGROUND AND PURPOSE: Laparoscopes used in laparoscopic surgery are manipulated by human means, passive systems or robotic systems. All three methods accumulate downtime when the laparoscope is cleaned and the optical perspective is adjusted. This work proposes a new navigation system that autonomously handles the laparoscope, with a view to reducing latency, and that allows real-time adjustment of the visual perspective. METHODS: The system designed is an intuitive mechatronic system with three degrees of freedom and a single active articulation. The system uses the point of insertion as the invariant point for navigation and has a work space that closely resembles an inverted cone. RESULTS: The mechatronic system has been tested in a physical trainer, cutting and suturing chicken parts, as well as in laparoscopic ovariohysterectomies in dogs and pediatric surgeries. In all the procedures, surgeons were able to auto-navigate and there was no visual tremor while using the system. Surgeons performed visual approaches in real time and had both hands free to carry out the procedure. CONCLUSION: This new mechatronic system allows surgeons to perform solo surgery. Cleaning and positioning downtime are reduced, since it is the surgeon him/herself who handles the optics and selects the best visual perspective for the surgery.