CAE's Endoscopy VR Simulator
Endoscopic procedures are one of the most commonly practiced medical procedures today. The Endoscopy VR Simulator from CAE Healthcare is a virtual reality endoscopic simulation platform that uses realistic, procedure-based content to teach cognitive and motor skills training. It is an interactive system with tactile feedback that permits learning and practice without putting patients at risk. There is visual realism (the tissue looks real), physical realism (the tissue 'moves' when it is touched), physiological realism (the virtual patient exhibits involuntary muscle contractions, bleeding, vital sign changes, etc.) and tactile realism (the user feels feedback resistance during the simulated procedure).
One of the modules of the AccuTouch simulator is for flexible bronchoscopy. In this module, the student can learn how to do bronchoalveolar lavage, endobronchial biopsy, transbronchial needle aspiration and transbronchial biopsy.
The second module that is available in the lab is for flexible colonoscopy. This module demonstrates how to navigate through the colon and to locate lesions. Screening for cancer can be learned, as well as procedures, such as polypectomies and biopsies, and patient positioning.
All modules provide educational content before the procedure, such as contraindications to the procedures, instruction on lesion type identification, and anatomy tutorials. During the cases, the patients give real-time feedback (verbal and vital sign changes) to indicate how well the trainee is performing the procedure. Clinical hints are also available, if the trainee desires them. After the case is completed, a detailed report is given, indicating which areas were satisfactorily completed, and which areas need more attention.
In addition to the fact that both of these models teach the motor skills and cognitive knowledge necessary to perform endoscopic procedures, the user becomes familiar with the handling of a scope.
One module of the EndoscopyVR Simulator is for fiberoptic bronchoscopy. The simulator consists of an anatomic model of the face, with an opening in one nare for nasal insertion of the fiberoptic bronchoscope. The anatomic model is attached to a long compartment which houses the motion sensor system. As the user inserts and manipulates the bronchoscope, the simulator senses the movements and adjusts the screen images in real time.
The bronchoscope appears real, although some slight modifications have been made. As the control lever for tip direction is moved up and down, the tip of the bronchoscope does not physically respond, but the computer senses the lever motion and causes a corresponding movement in the screen image. The suction button does not cause actual suction at the bronchoscope tip, but the image clears realistically and there is a suctioning noise from the computer.
The simulation begins with a brief review of teaching objectives. This is followed by a patient history and relevant history and physical exam results. If xrays or cat scans were performed, those images are available for review. The trainee is then requested to perform the selected procedure.
During the procedure help is available in two forms. The first aid is called Road Signs. When this option is selected, small initials appear over each segment branch as it becomes visible to keep the trainee oriented to where the tip of the bronchoscope is. There is also an option to view the entire respiratory tree from an external perspective. The full length of the bronchoscope is visible as it is currently positioned. This second option does not change in real time. On request the simulator stops and projects the anatomic map, then removes the map and resumes the simulation.
Feedback is given during the procedure (such as an audible patient cough if topical anesthetic is insufficient) as well as after the procedure is complete. Some of the feedback is relating to patient care (including how much lidocaine was administered and how many lesions were found and captured on video). Other output is intended to help the trainee develop a personal technique (such as the order the bronchial segments were visited).
Modules within the bronchoscopy simulation include basic maneuvers, lesion visualization, bronchial lavage, and tumor biopsy. There is also one pediatric difficult airway module currently in place.
The colonoscopic model consists of a colonoscope, a box containing the computer components, and a screen to view images. Cases are grouped, to allow trainees to focus on basic principles (introduction module) or to learn biopsy or polypectomy procedures. Within all modules, the AccuTouch simulator gives instructional information beforehand, real time patient feedback during the simulation, and constructive feedback after the simulation has been completed.
The colonoscope is shaped like a real colonoscope, including all the directional controls and adjunct buttons. The functionality has been removed from the scope, although the simulator senses what the user is doing and causes the image to change appropriately. The image appears blurry for a moment when water is injected; the suction button has a realistic sound associated with it, the intestinal walls start to collapse as air is withdrawn, when the colon is insufflated with air, it swells.
Each module case starts out with a patient history. This gives a clinical context to the procedure and may give a clue as to what pathologies to expect. If any diagnostic tests have been run, the values are noted. The anatomy consists of the large intestine from the rectum to the ileocecal valve, plus an appendix and an intubatable ileocecal valve with a few inches of the small intestine. During the case, the simulated patient responds in real time to the trainee's actions, both verbally and with vital sign changes. Sedation will cause a decrease in respiratory rate, with a possible decrease in oxygen saturation. Overinflation of the colon causes a reflex increase in blood pressure and heart rate. Excessive pressure on the mucosa will cause a perforation, which will end the case. When a polyp is excised or a biopsy is performed, the mucosa will bleed until appropriately cauterized. The polyp head will need to be retrieved.
The introduction module contains a series of videos including instruction on how to maneuver the scope and a tutorial on anatomy (developmental and procedurally relevant). There are also clinical tips on a number of topics. Text information is included for patient indications, contraindications, preparation, positioning, and complications. There is also an atlas with images of normal and pathologic tissues. Cases in the introductory module require only that the trainee insert the scope and visualize the mucosa, including any abnormalities. No procedures are performed. After the case, feedback is given in a number of areas, including level of patient discomfort, amount of air left in the colon, percent of mucosa visualized, and amount of sedation used.
Biopsies can be practiced on a different module. Instructional information is again presented, including an overview of the tools commonly used and clinical tips for performing the biopsy. The trainee is expected to do a full visualization of the colon and to take biopsies at appropriate sites. After the case, feedback is given to the trainee. This includes the same factors as the introductory module, plus factors relevant to biopsy, such as the number of times a forceps was opened in the working channel and a chart of the pathology sites, their locations, and number of images and successful biopsies at each site.
The polypectomy module is similar to the biopsy module. It has procedurally relevant videos, text and diagrams. The patient's history and exam are mentioned, along with relevant findings. While visualizing the colon, polyps will be encountered. The polyps should be excised, the stem cauterized, and the head retrieved. Feedback includes the standard information, plus metrics related to polypectomy: pathology location and type, percent of stalk removed, whether there were electrocautery marks on the mucosa, what wattage was used, and other parameters.