The American College of Cardiology (ACC) is reporting that a virtual reality simulator is a good way for physicians to learn how to perform risky catheter procedures such as carotid angiography. The study, to be published in the May 2, 2006, issue of the Journal of the American College of Cardiology, investigated how a virtual reality simulator, the Procedicus Vascular Interventional System Trainer (VIST), a product of Mentice AB of Gothenburg, Sweden, influenced clinical performance of twenty clinicians. According to the press release, “cardiologists committed fewer catheter errors, while performing the virtual procedure in less time, and subjecting the virtual patient to less X-ray imaging and smaller injections of contrast agent during the final run compared to the first one.”
The system (illustrated above; click on the image to enlarge) is explained by the company:
Procedicus VIST™, the vascular intervention system trainer, reproduces the physics and physiology of the human cardiovascular system such that a person can learn to perform various procedures such as cardiac catheterisation. The simulator is a generalized solution to endovascular simulation. The initial content scenarios focus on coronary, carotid, renal intervention and stenting as well as pacemaker lead placement. This simulation is combined with a haptic interface to give the user a natural, correct way to interact with the simulation. In addition there is an instructional system coupled to the simulation that provides a framework for learning from the simulation.
The training system consists of the software simulation of the cardiovascular system, the haptic interface device, the instructional system and two monitors, one for the synthetic x-ray and one for the instructional system. The simulation consists of modules replicating the hemodynamics, blood flow and dye contrast media mixing, and catheter-vasculature physical interaction. In addition, a module produces a synthetic x-ray image to replicate the fluoroscopic image used by interventional cardiologists to guide them during their work. The mathematics of these modules is explained in greater detail in several other documents.
In general, the mathematics usedc in the simulator is adapted from the cardiovascular modelling and analysis literature. Note that while the specific example described here is for coronary artery intervention, the same principles apply for simulating tool interactions with other vascular anatomy. It is largely a matter of creating new data sets to be input to the simulator to simulate another part of the body. In fact, the current system could be applied to non-vascular interventions without much modification and could even be adapted to flexible endoscopy. For a unique tool, some specific simulation code, which would plug into the existing simulator, might need to be developed for simulating its motion behaviour and interaction with tissue. Beyond training, the same simulation core can be adapted in the future to develop mathematical prototypes of tools and procedures as well as used in conjunction with patient data to perform individualized procedure rehearsals.