Hajime Kenmotsu

Objective assessment of laparoscopic suturing skills using a motion-tracking system

BackgroundLaparoscopic suturing skills are important for advanced laparoscopic surgery. However, objective assessment of these skills has not yet been established. The aim of this study was to assess the laparoscopic suturing skills of novice and experienced surgeons using an electromagnetic motion-tracking system.MethodsA total of 18 surgeons, who were all right-handed, were divided into the following two groups according to their experience as an operator in laparoscopic surgery: 9 novice surgeons (fewer than 10 laparoscopic procedures) and 9 experienced surgeons (more than 50 laparoscopic procedures). The subjects performed an intracorporeal suturing task in an inanimate box laparoscopic trainer while the movements of their forceps were evaluated using an electromagnetic motion-tracking system. Their laparoscopic skills were assessed on the basis of the time, path length, and average speed of the forceps in each hand.ResultsExperienced surgeons completed the suturing task significantly faster than novice surgeons did. The left path length was significantly shorter for experienced surgeons than for novice surgeons, whereas the right path lengths did not differ. The right average speed of knot tying was significantly faster for experienced surgeons than for novice surgeons, whereas the left average speeds did not differ.ConclusionsEvaluation of psychomotor skills in laparoscopic suturing using an electromagnetic motion-tracking system revealed better results for experienced surgeons than for novice surgeons in terms of the time taken, left path length, and right speed of knot-tying. Furthermore, surgical proficiency due to experience can affect surgical dexterity of each hand differently. The present study also demonstrates the efficacy of this system for objective evaluation of laparoscopic suturing skills.

Skills assessment using a virtual reality simulator, LapSim™, after training to develop fundamental skills for endoscopic surgery

Abstract Education and training to maintain medical safety are very important within clinical settings. We have established a training center for endoscopic surgery and we regularly hold a unique training course, which focuses on the development of fundamental skills. One hundred and ninety-four surgeons who participated in our training course were divided into four groups according to their experience in performing laparoscopic procedures. Group 1: 0–19 laparoscopic procedures (n=44). Group 2: 20–49 laparoscopic procedures (n=53). Group 3: 50–99 laparoscopic procedures (n=46). Group 4: more than 100 laparoscopic procedures (n=55). All subjects underwent evaluation for “Lifting & Grasping” using a virtual reality (VR) simulator, LapSim™, before and after the training course. The mean efficiency score, time to completion and tissue damage after training were significantly improved after the training as compared with before training. Before training, subjects with greater experience had better scores. However, the only significant difference in the score was between the low experience group and greatest experience group. After training, the score increased in all groups compared with that before training, and there was no significant difference between groups. This study demonstrates the feasibility of using a VR simulator to assess fundamental skills for endoscopic surgery after training. We found that the scores for the task were associated with the level of experience of the surgeons.

The effect of CyberDome, a novel 3-dimensional dome-shaped display system, on laparoscopic procedures

BackgroundLaparoscopic surgeons require extended experience of cases to overcome the lack of depth perception on a two-dimensional (2D) display. Although a three-dimensional (3D) display was reported to be useful over two decades ago, 3D systems have not been widely used. Recently, we developed a novel 3D dome-shaped display (3DD) system, CyberDome.Study designIn the present study, a total of 23 students volunteered. We evaluated the effects of the 3DD system on depth perception and laparoscopic procedures in comparison with the 2D, a conventional 3D (3DP) or the 2D high definition (HD) systems using seven tasks.ResultsThe 3DD system significantly improved depth perception and laparoscopic performance compared with the 2D system in six new tasks. We further found that the 3DD system shortened the execution time and reduced the number of errors during suturing and knot tying. The 3DD system also provided more depth perception than the 3DP and 2D HD systems.ConclusionsThe novel 3DD system is a promising tool for providing depth perception with high resolution to laparoscopic surgeons.

Three-dimensional high-definition neuroendoscopic surgery: A controlled comparative laboratory study with two-dimensional endoscopy and clinical application

BACKGROUND The purpose of this research was to investigate the usefulness of three-dimensional (3D) endoscopy compared with two-dimensional (2D) endoscopy in neuroendoscopic surgeries in a comparative study and to test the clinical applications. METHODS Forty-three examinees were divided into three groups according to their endoscopic experience: novice, beginner, or expert. Examinees performed three separate tasks using 3D and 2D endoscopy. A recently developed 3D high-definition (HD) neuroendoscope, 4.7 mm in diameter (Shinko Optical Co., Ltd., Tokyo, Japan) was used. In one of the three tasks, we developed a full-sized skull model of acrylic-based plastic using a 3D printer and a patients thin slice computed tomography data, and evaluated the execution time and total path length of the tip of the pointer using an optical tracking system. Sixteen patients underwent endoscopic transnasal transsphenoidal pituitary surgery using both 3D and 2D endoscopy. RESULTS Horizontal motion was evaluated using task 1, and anteroposterior motion was evaluated with task 3. Execution time and total path length in task 3 using the 3D system in both novice and beginner groups were significantly shorter than with the 2D system (p < 0.05), although no significant difference between 2D and 3D systems in task 1 was seen. In both the novice and beginner groups, the 3D system was better for depth perception than horizontal motion. No difference was seen in the expert group in this regard. The 3D HD endoscope was used for the pituitary surgery and was found very useful to identify the spatial relationship of carotid arteries and bony structures. CONCLUSIONS The use of a 3D neuroendoscope improved depth perception and task performance. Our results suggest that 3D endoscopes could shorten the learning curve of young neurosurgeons and play an important role in both general surgery and neurosurgery.

Scorpion shaped endoscopic surgical robot for NOTES and SPS with augmented reality functions

In the process of developing an endoscopic surgical robot system that adapts to NOTES (Natural Orifice Translumenal Endoscopic Surgery) and SPS (Single port surgery), by making the tip a soft tubular structure and adding an augmented reality function to the system, we were able to improve the general function of the surgical robot system. First, we added a haptic sense function to avoid breaking the soft tissue and to avoid the danger of cutting it. These occur due to the small size of the touching surface between the tip of the robot arm and the soft tissue. We were able to conduct operation by feeding back to the surgeon the force applied to the soft tissue by detecting the haptic sense of the small forceps at the tip through measuring the tension variation at the base of the wire that drives the robot arm. We also mounted various numbers of augmented reality function such as grasping the exact location of the surgical robot inside the human body and information on how the robot is reaching the location of surgery. As a result, we were able to build a system that can conduct safe surgery with the systems two main characteristics - the smallness and the high degree of freedom to move.

Surgical bedside master console for neurosurgical robotic system

PurposeWe are currently developing a neurosurgical robotic system that facilitates access to residual tumors and improves brain tumor removal surgical outcomes. The system combines conventional and robotic surgery allowing for a quick conversion between the procedures. This concept requires a new master console that can be positioned at the surgical bedside and be sterilized.MethodsThe master console was developed using new technologies, such as a parallel mechanism and pneumatic sensors. The parallel mechanism is a purely passive 5-DOF (degrees of freedom) joystick based on the author’s haptic research. The parallel mechanism enables motion input of conventional brain tumor removal surgery with a compact, intuitive interface that can be used in a conventional surgical environment. In addition, the pneumatic sensors implemented on the mechanism provide an intuitive interface and electrically isolate the tool parts from the mechanism so they can be easily sterilized.ResultsThe 5-DOF parallel mechanism is compact (17 cm width, 19cm depth, and 15cm height), provides a 505,050 mm and 90° workspace and is highly backdrivable (0.27N of resistance force representing the surgical motion). The evaluation tests revealed that the pneumatic sensors can properly measure the suction strength, grasping force, and hand contact. In addition, an installability test showed that the master console can be used in a conventional surgical environment.ConclusionThe proposed master console design was shown to be feasible for operative neurosurgery based on comprehensive testing. This master console is currently being tested for master-slave control with a surgical robotic system.

Gastric endoscopic submucosal dissection using novel 2.6-mm articulating devices: an ex vivo comparative and in vivo feasibility study.

BACKGROUND AND STUDY AIMS The conventional procedure of endoscopic submucosal dissection (ESD) is technically demanding. This study investigated the efficiency of novel articulating devices (maximum diameter 2.6 mm), which can be used with commercially available, standard endoscopes. PATIENTS AND METHODS In an ex vivo comparative study, eight endoscopists were divided into novices and experienced operators, and performed ESD using new devices and the conventional setup. An in vivo animal experiment was performed by two experts. Procedure times for incision and dissection were recorded, and unit times for circumferential length and area of specimens were calculated. RESULTS All procedures were successfully completed with en bloc resection. In the ex vivo study, the unit procedure times for incision and dissection by novices were significantly shorter using the new system (P < 0.01 and P < 0.05), whereas there was no significant difference for experienced endoscopists. Perforation occurred during one procedure in which the new system was used. The in vivo experiments were successfully completed without adverse events. CONCLUSIONS ESD using novel articulating devices was feasible. These devices were able to reduce the procedure time for novices.

Novel, high-definition 3-D endoscopy system with real-time compression communication system to aid diagnoses and treatment between hospitals in Thailand.

Traditionally, laparoscopy has been based on 2‐D imaging, which represents a considerable challenge. As a result, 3‐D visualization technology has been proposed as a way to better facilitate laparoscopy. We compared the latest 3‐D systems with high‐end 2‐D monitors to validate the usefulness of new systems for endoscopic diagnoses and treatment in Thailand.

Training system for NOTES and SPS surgery robot that enables spatiotemporal retrospective analysis of the training process.

Within the digestive organ surgery robot R&D project, our research team aims to develop a surgical robot training device with an interface identical to that of the actual device. The training device uses an organ model that changes shape in real time to train operators to grab, cut open, and cut off soft tissues and close wounds using the actual device. To increase the effectiveness of the training device, we added functions to save the movements of the robot in training and changes in the operation field. By recreating the situation during training, we were able to analyze in four dimensions (4D) various changes in the operation field that the operator cannot see during training. This new function not only enabled us to analyze the contents of the training in detail, but also to report any problems in development and design of the actual device.

VR training system for endoscopic surgery robot: Development of a system enabling 4D analysis of surgical technique training

Our research group is currently developing an endoscopic surgical robot for digestive organs. In the current study, we sought to train surgeons to manipulate the system we are developing for clinical applications. To this end, we are developing a training system with the same interface as the real system, so that surgeons in training can practice basic manipulations and surgical techniques using organ models. To learn the basic manipulations of the system, we emphasized training the surgeon to operate the robotic arms, as this is the biggest difference from the conventional surgical techniques. We set up several types of tasks for the trainee, so that a beginner trainee could get used to operating the robot arms of the system. We developed a surgical training method using a stomach model reconstructed from MRI data sets. In addition to basic surgical techniques such as grabbing, lifting and cutting open soft tissue with the robot arm, we enabled the training system to perform techniques necessary for the surgical system, such as delivering water to the surgical field in case of bleeding, and clipping of incision sites. We added a function to record the performance of the trainee, enabling the system to analyze changes of the surgical field and robot arms in four dimensions during training.