The last thing a patient facing surgery wants is a novice learning the ins and out of a particular procedure on them. Immersion Medical, Gaithersburg, Md., (immersion.com) says it feels their pain and developed a range of surgery simulators that could eliminate such situations. It says the equipment is an effective way to learn procedures such as endovascular, endoscopic, intravenous, and laparoscopic.

“Our software engineers, clinical developers, and medical modelers create simulations that are as realistic as possible,” says physician Kevin Kunkler, Immersion VP and medical director. “In our laparoscopic simulator, for instance, you can feel the surgical instrument pushing against a liver or gall bladder.”

Kunkler says this haptic feedback is crucial to medical simulation because, even though graphics and animations look real, they cannot convey what it feels like to break through a venal wall with a needle, or cut through tissue surrounding a gall bladder. The simulators with TouchSense haptic feedback generate finely tuned resistance that mimics the feel of the real thing. For example, a surgeon can advance a catheter or endoscope into a virtual patient until the diameter of the anatomy is smaller than the instrument and the resistance will be close to what would actually be felt during the real procedure.

The system uses realistic graphical renderings and advanced control algorithms to model anatomy and physiology. These simulations are said to provide a clear and immediate understanding of how a surgical procedure should be done. This understanding could help set up clinical trials and speed market acceptance. Another potential use is to help designers evaluate surgical tools.

The medical simulators are said to provide models which can be tuned for authentic responses, creating natural, unscripted, interactions between tools and tissue. Surgical models were designed partly under the guidance of leading clinicians, through observation of operating procedures, and images of real CAT and MRI films.

Before the simulators, doctors trained on cadavers. “They provide the correct anatomy, but don't have the physiology one sees in our simulators,” says Kunkler. Animals provide a physiology, but the anatomy is wrong. Animal-rights activists, the high cost of cadavers, and patients wanting an experienced physician are pushing the move to more simulation-based training.

An increase in the number of medical students is also putting pressure on academic hospitals. Clinical studies show that simulators help students learn faster than conventional training methods. What's more, better training lowers the learning curve for new devices and encourages faster adoption.

“Simulators can also throw students an occasional curve,” says Kunkler. “For example, simulating a catheter snagging on tissue teaches students how to deal with it.” Simulators also let medical students practice as long as they want before advancing to the next difficulty level.

“Each simulator supports training of several procedures,” he adds. “For example, our endovascular unit allows inserting a catheter inside a vessel, along with a guide wire and balloon, as would be necessary for angioplasty. Stents are positioned in the diseased portion of the vessel. Cardiologists report it provides an excellent replication of what happens in an actual catheterization lab. This same system supports training in electro-physiology where cardiologists place leads in heart chambers or to blood vessels on its surface. You sense the heart beating and manipulate pacemaker controls to set the heart into a normal rhythm.”

The LaparoscopyVR Virtual Reality unit (LapVR) supports practice in 15 essential skills, as well as examining bowels, and gall-bladder removals. The equipment comes with a monitor, virtual camera, tools (trocars), and modules packaged in an ergonomic, wheeled cart.