The role of cognitive abilities in laparoscopic simulator training

Learning minimally invasive surgery (MIS) differs substantially from learning open surgery and trainees differ in their ability to learn MIS. Previous studies mainly focused on the role of visuo-spatial ability (VSA) on the learning curve for MIS. In the current study, the relationship between spatial memory, perceptual speed, and general reasoning ability, in addition to VSA, and performance on a MIS simulator is examined. Fifty-three laparoscopic novices were tested for cognitive aptitude. Laparoscopic performance was assessed with the LapSim simulator (Surgical Science Ltd., Gothenburg, Sweden). Participants trained multiple sessions on the simulator until proficiency was reached. Participants showed significant improvement on the time to complete the task and efficiency of movement. Performance was related to different cognitive abilities, depending on the performance measure and type of cognitive ability. No relationship between cognitive aptitude and duration of training or steepness of the learning curve was found. Cognitive aptitude mediates certain aspects of performance during training on a laparoscopic simulator. Based on the current study, we conclude that cognitive aptitude tests cannot be used for resident selection but are potentially useful for developing individualized training programs. More research will be performed to examine how cognitive aptitude testing can be used to design training programs

Sentinel node biopsy in prostate and bladder cancer using magnetic nanoparticles and a new magnetic detection technique

Sentinel node biopsy in prostate and bladder cancer using magnetic nanoparticles and a new magnetic detection techniqu

Perceptual speed and psychomotor ability predict laparoscopic skill acquisition on a simulator

Objective Performing minimally invasive surgery puts high demands on a surgeon’s cognitive and psychomotor abilities. Assessment of these abilities can be used to predict a surgeon’s learning curve, to create individualized training programs, and ultimately in selection programs for surgical training. The aim of this study was to examine the influence of cognitive and psychomotor ability on the training duration and learning rate. Design A prospective quasiexperimental field study regarding the influence of cognitive and psychomotor ability, baseline measures of time to complete task, damage to tissue, and efficiency of movement, age, and gender on the number of sessions needed to reach a predefined performance level on a laparoscopy simulator. The same variables were investigated as predictors of the learning rate. Setting The study was performed at the Experimental Center for Technical Medicine at the University of Twente, The Netherlands. Participants In all, 98 novices from the Master program of Technical Medicine followed a proficiency-based basic laparoscopic skills training. Results Perceptual speed (PS) predicted training duration (hazard ratio = 1.578; 95% CI = 1.084, 2.300; p = 0.017). Cognitive (b = −0.721, p = 0.014) and psychomotor ability (b = 0.182, p = 0.009) predicted the learning rate of time to complete the task. Also, the learning rate for participants with higher levels of PS was lower (b = 0.167, p = 0.036). Psychomotor ability also predicted the learning rate for damage to tissue (b = 0.194, p = 0.015) and efficiency of movement (b = 0.229, p = 0.004). Participants with better psychomotor ability outperformed other participants across all sessions on all outcome measures. Conclusions PS predicted training duration in a basic laparoscopic skills training and the learning rate for the time to complete the task. Psychomotor ability predicted the learning rate for laparoscopic skill acquisition in terms of time to complete task, damage to tissue, and efficiency of movements. These results indicate early automation of basic laparoscopic skill. Careful selection of the cognitive abilities tests is advised for use in training programs and to identify individuals who need more training

An overview of systems for CT- and MRI-guided percutaneous needle placement in the thorax and abdomen

Background Minimally invasive biopsies, drainages and therapies in the soft tissue organs of the thorax and abdomen are typically performed through a needle, which is inserted percutaneously to reach the target area. The conventional workflow for needle placement employs an iterative freehand technique. This article provides an overview of needle-placement systems developed to improve this method. Methods An overview of systems for needle placement was assembled, including those found in scientific publications and patents, as well as those that are commercially available. The systems are categorized by function and tabulated. Results Over 40 systems were identified, ranging from simple passive aids to fully actuated robots. Conclusions The overview shows a wide variety of developed systems with growing complexity. However, given that only a few systems have reached commercial availability, it is clear that the technical community is struggling to develop solutions that are adopted clinically

Single-handed controller reduces the workload of flexible endoscopy

The control of the conventional flexible endo- scope is non-ergonomic and non-intuitive. A novel single- handed interface could reduce the experienced workload, without reducing current efficiency or effectiveness of endoscope manipulation. The aim of this study is to eval- uate the workload, efficiency and effectiveness of a single- handed controller in colonoscopy, in comparison to a bimanual controller and the conventional angulation wheels. Twenty-one inexperienced students performed colonoscopies on a computer simulator using either the single-handed controller with a joystick interface, a bimanual controller with a joystick interface or the con- ventional angulation wheels. Participants performed three sessions of colonoscopies. After each session, the experi- enced workload was evaluated using a seven-component absolute scoring scale. Efficiency of the procedure was evaluated by the cecal intubation time and total-used scope length. Effectiveness was evaluated by the percentage of bowel wall visualization. The total workload of the single- handed controller was lower compared to the conventional angulation wheels for all three sessions. The total workload of the bimanual controller was lower compared to the conventional angulation wheels in the second and third session and also lower compared to the single-handed controller in the third session. There was no significant difference between the three control interfaces in time efficiency, used scope length or visualization performance. Single-handed and bimanual controllers with a joystick interface are a feasible approach to reduce the workload of colonoscopy without reducing efficiency or effectiveness of endoscope manipulation

A feasibility study of optical flow-based navigation during colonoscopy

In this study, it was shown that using the optical flow and the focus of expansion, obtained from the monocular camera at the beginning of a colonoscope, (semi-)automated steering of flexible endoscopes might become possible. This automation might help to increase colonoscopy efficiency, but is also applicable in other areas

The Use of the Focus of Expansion for Automated Steering of Flexible Endoscopes

Colon cancer screening remains a time-consuming and expensive clinical process. Automating flexible endoscopy has the potential to increase screening efficiency. In this research the images captured by the camera at the endoscope tip are used to find the heading direction of the endoscope. Comparing the current heading direction to the desired target direction in a computer algorithm is expected to allow automated steering of the endoscope. Heading direction determination is achieved using an estimation of the focus of expansion (FOE) from the optical flow field. The resulting heading direction is compared to results obtained manually by several human observers. From our experiments it becomes clear that the FOE can be used as a reliable estimator for heading direction in human colonoscopy images. Additionally, the automated results have an intraclass correlation of 89% with the manual results, demonstrating that the algorithm works as expected. It is anticipated that the final steering algorithm can be used in a variety of motorized flexible endoscope applications

System for CT-guided needle placement in the thorax and abdomen: A design for clinical acceptability, applicability and usability

BACKGROUND: Various systems exist for CT-guided needle placement in the thorax and abdomen, but widespread adoption is lacking. The goal of this work is to develop a system for precise needle placement with a design focus on clinical acceptability, applicability and usability. METHODS: A system was outlined incorporating a needle guide on a mechanism with a remote centre of motion, manually placeable around the patient at the desired entry point and lockable by push-button to the CT table. System and patient are scanned for system-to-CT registration and target specification. The needle guide is automatically aimed at the target, for manual needle insertion to specified depth. RESULTS: A fully functional prototype was realized, achieving 1.2±0.6 mm placement error at 79.0±8.4 mm depth and 2.1±0.7 mm at 156.0±6.9 mm for 2×12 in- and out-of-plane punctures in a gelatin phantom. CONCLUSIONS: The system enables precise needle placement in a single insertion and is ready for its first clinical deployment