Interpretation of motion analysis of laparoscopic instruments based on principal component analysis in box trainer settings.

BACKGROUND: Motion analysis parameters (MAPs) have been extensively validated for assessment of minimally invasive surgical skills. However, there are discrepancies on how specific MAPs, tasks, and skills match with each other, reflecting that motion analysis cannot be generalized independently of the learning outcomes of a task. Additionally, there is a lack of knowledge on the meaning of motion analysis in terms of surgical skills, making difficult the provision of meaningful, didactic feedback. In this study, new higher significance MAPs (HSMAPs) are proposed, validated, and discussed for the assessment of technical skills in box trainers, based on principal component analysis (PCA). METHODS: Motion analysis data were collected from 25 volunteers performing three box trainer tasks (peg grasping/PG, pattern cutting/PC, knot suturing/KS) using the EVA tracking system. PCA was applied on 10 MAPs for each task and hand. Principal components were trimmed to those accounting for an explained variance > 80% to define the HSMAPs. Individual contributions of MAPs to HSMAPs were obtained by loading analysis and varimax rotation. Construct validity of the new HSMAPs was carried out at two levels of experience based on number of surgeries. RESULTS: Three new HSMAPs per hand were defined for PG and PC tasks, and two per hand for KS task. PG presented validity for HSMAPs related to insecurity and economy of space. PC showed validity for HSMAPs related to cutting efficacy, peripheral unawareness, and confidence. Finally, KS presented validity for HSMAPs related with economy of space and knotting security. CONCLUSIONS: PCA-defined HSMAPs can be used for technical skills' assessment. Construct validation and expert knowledge can be combined to infer how competences are acquired in box trainer tasks. These findings can be exploited to provide residents with meaningful feedback on performance. Future works will compare the new HSMAPs with valid scoring systems such as GOALS.

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.

Face, content, and construct validity of the EndoViS training system for objective assessment of psychomotor skills of laparoscopic surgeons.

BACKGROUND: The aim of this study is to present face, content, and constructs validity of the endoscopic orthogonal video system (EndoViS) training system and determines its efficiency as a training and objective assessment tool of the surgeons' psychomotor skills. METHODS: Thirty-five surgeons and medical students participated in this study: 11 medical students, 19 residents, and 5 experts. All participants performed four basic skill tasks using conventional laparoscopic instruments and EndoViS training system. Subsequently, participants filled out a questionnaire regarding the design, realism, overall functionality, and its capabilities to train hand-eye coordination and depth perception, rated on a 5-point Likert scale. Motion data of the instruments were obtained by means of two webcams built into a laparoscopic physical trainer. To identify the surgical instruments in the images, colored markers were placed in each instrument. Thirteen motion-related metrics were used to assess laparoscopic performance of the participants. Statistical analysis of performance was made between novice, intermediate, and expert groups. Internal consistency of all metrics was analyzed with Cronbach's α test. RESULTS: Overall scores about features of the EndoViS system were positives. Participants agreed with the usefulness of tasks and the training capacities of EndoViS system (score >4). Results presented significant differences in the execution of three skill tasks performed by participants. Seven metrics showed construct validity for assessment of performance with high consistency levels. CONCLUSIONS: EndoViS training system has been successfully validated. Results showed that EndoViS was able to differentiate between participants of varying laparoscopic experience. This simulator is a useful and effective tool to objectively assess laparoscopic psychomotor skills of the surgeons.

PsT1: A Low-Cost Optical Simulator for Psychomotor Skills Training in Neuroendoscopy.

BACKGROUND: Well-developed psychomotor skills are important for competence in minimally invasive surgery. Neuroendoscopy is no exception, and adaptation to different visual perspectives and careful handling of the surgical instruments are mandatory. Few training systems, however, focus on developing psychomotor skills for neuroendoscopy. Here, we introduce a new training system called PsT1 that provides visual feedback via the use of simple optics that emulate the endoscope at 0° and 30°. Time and error metrics are generated automatically with integrated software to ensure objective assessment. METHODS: Neuroendoscopic optics were emulated with a low-cost, commercially available universal serial bus 2.0 camera and a light-emitting diode light source. Visual feedback of 30° was obtained by displacing the optical axis of the universal serial bus camera by 30°, and metrics (time, precision, and errors) were generated automatically by the software. Three evaluation modules were developed (spatial adaptation, depth adaptation, and dissection), and 35 expert and nonexpert neurosurgeons performed an initial evaluation of the system. RESULTS: A total of 81% and 90% of surgeons agreed that the visuals were satisfactory and movement and control were accurately replicated, respectively. The advantages and disadvantages of the system were compared. CONCLUSIONS: Here, we present a novel, low-cost, and easy-to-implement training system for developing basic neuroendoscopic psychomotor skills. The use of objective metrics, surgical instruments, and emulation of the neuroendoscope at 0° and 30° are competitive advantages of the current system.

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.

Mechatronic assistant system for dental drill handling.

BACKGROUND: Holding a dental tool for many hours of work is reflected in fatigue and manual tremor, which causes bad handling of rotatory instruments and consequently injuries within the buccal cavity. At present there exists no system to help the medical dentist in the support and handling of the dental drill. We propose the use of a mechatronic system to help the odontologist in handling the dental drill. METHODS: The mechatronic system consists of an articulated arm with force sensors and actuators that are activated electronically. The mechanism was developed so that the handpiece is held simultaneously by the mechatronic arm and the hand of the dentist. Expert dentists and odontology students were asked to execute tasks to assess positioning accuracy and system resolution. Students performed positioning tasks to evaluate adaptation to the system. The subjects drew the contour of a circle with and without the mechatronic assistant to assess positioning accuracy. Similarly, they made cavities on acrylic typodonts to evaluate resolution and accuracy. Adaptation to the system was evaluated by inserting the drill burr into cavities previously made. RESULTS: The mechatronic system provides support and stability while handling the dental drill. The threshold of force required to move the mechanism prevents involuntary movements affecting the quality of work made on cavities. Positioning accuracy was improved by 53% (p < 0.017) using the system. Similarly, resolution of drilling was improved by 76% (p < 0.001). CONCLUSION: We have developed the first mechatronic system to assist dentists in handling the dental drill. The arm allows the dentist to manipulate the tool with smooth and precise movements during the preparation of dental cavities with the application of force. The mechatronic system minimizes manual tremor due to fatigue and reduces the risk of iatrogenic dental injuries.

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.

Adaptation to a dynamic visual perspective in laparoscopy through training in the cutting task.

BACKGROUND: Laparoscopic surgery demands of surgeons special skills acquired only through practice. Laparoscopic training systems traditionally have an optical system that, once positioned, remains fixed and cannot refresh the perspective unless the task is interrupted and the camera repositioned. During a surgery, the visual perspective changes constantly to relocate the surgical target. This difference is a limitation for any novice surgeon. This report proposes the use of a mechatronic system that allows the trainee to handle optics dynamically during training in the cutting task and thereby adapt to dynamic relocation of the surgical target. METHODS: The study was conducted in two phases. The first phase involved using fixed optics to cut a circle drawn on a piece of cloth. The second phase involved the same cutting task but with the visual perspective changed dynamically by the user via a mechatronic assistant. RESULTS: The data show that by adapting to dynamic optics, medical trainees can quickly and easily handle and locate the task with real-time changes in visual perspective and can also improve task quality. A significant statistical difference was found between the two methods performed (p < 0.0025). Variance analysis also was applied to the mean values of the scores achieved by both groups (p < 0.0001). CONCLUSIONS: A new laparoscopic training method has been developed. It applies real-time dynamic optics that trainees assist by means of a mechatronic device harnessed to their body. This new training tool allows resident trainees to adapt quickly to the work environment of dynamic optics and thus enter the surgical scenario more rapidly and confidently after mastering the visual-spatial aspect of the laparoscopic approach.

Millimetric laparoscopic surgery training on a physical trainer using rats.

PURPOSE: To demonstrate the possibility of laparoscopic technique training and refinement at the millimetric level. MATERIAL AND METHODS: A physical trainer and Winstar rats were used. RESULTS: The training system is visually similar to pneumoperitoneum. The laparoscopic technique is perfected in a visual space illuminated by white light, with two-dimensional feedback and at a geometric level that allows for refinement of the technique. CONCLUSIONS: It is possible to refine the technique at this geometric level at a low cost and without requiring laparoscopic equipment. In addition, optics tests indicate the possibility in the short term of refining the laparoscopic technique to the microanastomotic level.

Laparoscopic Learning Evaluation over the Internet.

Learning and refining laparoscopic surgical technique requires a continuous training process. For this learning process to have value, it must include objective evaluations and the interaction of expert surgeons. These surgeons, however, are normally located at third-level hospitals, so it is difficult for them to be available for this important process. In order to bring together learning and evaluation, we developed an Internet-based evaluation system for laparoscopic surgical technique. The system applies the McGill Inanimate System for Training and Evaluation of Laparoscopic Skills (MISTELS) evaluation methodology, and is remotely supervised by surgeons who specialize in laparoscopy.

Laparoscopic Nissen solo surgery using PMAT (first experience).

This article describes the use of a Postural Mechatronic Assistant Trainer (PMAT) in pediatric Nissen surgery. This mechatronic system enables users to establish the logistical considerations for solo surgery and determine the advantages this new tool offers for the autonomous handling of optics.

Tonatiuh II: assisting manipulator for laparoscopic surgery.

In this article we show the design of the Tonatiuh II robotic manipulator. This robotic assistant has an original electromechanical configuration and respects the laparoscope center of insertion as an invariant point for navigation in the work space. The manipulator went through several stages before reaching its final version. Surgical trials have shown the robot to be useful in the operating room and as a training assistant in specialty microsurgery.

Novel laparoscopic home trainer.

BACKGROUND: Minimum-invasion surgery is performed by means of 2-dimensional visual feedback and without haptic sensitivity. This demands that specialty surgeons adapt to and develop new psychomotor abilities. These abilities can only be learned, developed, and maintained through training. Training technology has been divided into virtual trainers and physical trainers. The former, due to their high cost, have not had the expected academic impact, whereas the latter, although an excellent low-cost alternative, do not offer the visual handling options for refining the required psychomotor abilities. The purpose of this article is to describe the design of a box trainer which can establish a closer relationship with the visual and functional perspectives of optics during surgery, thus establishing better learning protocols. METHODS: A laparoscopic surgery trainer was designed and built based on the shape of the abdominal cavity formed during such surgery. The visual feedback is achieved with a color mini-camera whose position and orientation are controlled by means of a magnetic system with 0 and 45-degree optics options. RESULTS: A trainer which allows for changes in visual perspective, for developing abilities and skills, with optics other than those of 0 degrees within a geometric space similar to that of the pneumoperitoneum has been designed. CONCLUSIONS: A training system which provides illumination and visual perspective conditions similar to those of real surgery using 0 and 45-degree optics has been designed. The training system is portable and easy to connect for training purposes. Its ports allow for various options that help to improve skills and propose new approaches.