Manchester Visualization Centre has been working closely with the
of Neurosurgery at the Leeds General Infirmary to develop cost effective
web-deliverable VRML medical surgical simulations and training material.
work has recently received funding from the European Commission as part
the WebSET (Web-based Standard Educational Tools) project
These simulations all share the same basic characteristic of introducing a needle or catheter to the body, and the insertion of the said implement to puncture or pierce some internal tissue. To date the work has been concentrated on the development of techniques to improve the feedback given to the user.
The Lumbar Puncture simulator, one of most perfect educational application developed using ParallelGraphics' Cortona SDK, was created in order to give the simulation user some notion of when the needle punctures the membrane surrounding the spinal chord. When performing this procedure for real, the clinician will experience a popping sensation and a sound is played to represent this event in the simulator.
A technique was needed to allow VRML to communicate with the Logitech's force-feedback mouse. Data needs to be both sent to, and read from the mouse itself, in order to synchronise and control haptic effects. The most obvious way of performing this task was to utilise VRML's EAI, and Java, in order to communicate with the C++ SDK controlling force-feedback effects.
However, due to applet security restrictions, and the general complexity of communicating between so many technologies, a different approach was necessary.
According to developers Cortona SDK provided the perfect solution to their problems. The embedding of Cortona VRML Client into an MFC application and using the Cortona SDK as a programming interface into the VRML scene made it possible to communicate between VRML and the force feedback SDK with the minimum of effort. As such, mouse movement can be monitored and used to control the needle motion in the simulator, and collision detection results can be detected allowing the facilitation of appropriate haptic effects. The documentation and examples included with the Cortona SDK proved extremely helpful and greatly aided the development process.