Development of colonoscopy teaching simulation.

After 17 years of prototyping, a first release version of the St Mark's Hospital teaching simulator is in final preparation. Advances in computer processing power and graphics cards make it possible to achieve real-time processing of colon and endoscope characteristics and a simulated endoscopic view at an acceptable cost. Realistic feel or "force feedback" for all instrument controls and shaft movements is incorporated. To make the simulator more than a "video game", a package of teaching and assessment features is to be incorporated, including interactive animated graphics to explain particular endoscope loops and situations and the variations of colonic anatomy that are typically encountered. Simulation should spare patients from being used for the early phases of training and should speed up and quantify the learning process. Simulators may introduce even experienced endoscopists to some of the advanced options available in current or future endoscopes or accessories, as well as the use of imminent new technology such as the magnetic imaging system.

Real-time magnetic three-dimensional imaging of flexible endoscopy.

Because of the variability of the colonic anatomy from patient to patient, colonoscopy may be technically difficult to perform and teach, and lesions may be localized inaccurately by the endoscopist. Endoscopists understandably have abandoned fluoroscopy as an adjunct because of its expense, complexity, and potential hazard. The authors have developed a novel method of magnetic imaging that gives real-time views in simulated three dimensions of the endoscope configuration and the location of its tip in the abdomen. The system is inherently safe and easy to use, although it currently requires a catheter to be inserted into the instrumentation channel. Preliminary experience suggests that this approach will be a significant help to endoscopists performing colonoscopy, particularly to those who are currently learning or less experienced.

First clinical results with a real time, electronic imager as an aid to colonoscopy.

The early clinical results are described of a real time, electromagnetic imaging system as an aid to colonoscopy. After gaining experience with the use of the system, one experienced endoscopist was randomised to perform consecutive colonoscopies either with (n = 29) or without (n = 26) the imager view. All procedures were recorded on computer disk and replayed for retrospective analysis. Total colonoscopy was achieved in all patients except one (imager view not available). Comparing intubation time and duration of loop formation per patient, there was no significant difference between the two study groups. The number of attempts taken to straighten the colonoscope pre patient, however, was less when the endoscopist was able to see the imager view, p = 0.03. Hand pressure was also more effective when the endoscopist and endoscopy assistant could see the imager display, p = 0.02. Preliminary experience suggests that real time, electronic imaging of colonoscopy is safe, effective, and will improve the accuracy of the procedure.

Non-radiological technique for three-dimensional imaging of endoscopes.

A novel system is described which images in three dimensions, the total configuration of a colonoscope without the use of conventional radiological techniques. A low intensity magnetic field is used in conjunction with a miniature inductive sensor. The system intrinsically safe and it is potentially inexpensive and capable of being used in a normal hospital environment. Clinical trials are described in which the system is validated in terms of its suitability for the application. Magnetic and conventional X-ray images obtained ex vivo with the endoscope held in various configurations and comparisons in the patients confirm the practical applicability of the new system.