Ying Li, Ken Brodlie and Nicholas Phillips *

School of Computer Studies, University of Leeds, UK

http://www.scs.leeds.ac.uk/vis/ying/

Web-based VR Training Simulator for Percutaneous Rhizotomy

January 29, 2000* Department of Neurosurgery, Leeds General Infirmary, UK

Contents

• Motivation

• Surgical procedure

• The simulator

• Conclusions

Motivation

• The limitation of current VR training systems

• The advantages of web based VR environment

• It is possible

Dedicated, expensive equipment

Accessible, scalable, low cost

The Surgical Procedure - Percutaneous Rhizotomy

Lesion Generator

Insert needle electrode at correct position & orientation on face

Locate & puncture foramen ovale to access and burn ganglion nerve

• Highly skilled operation

Why is Simulation Useful

• Risky

• Awkward to train new staff

Especially to locate foramen ovale

Patient awake for part of the procedure

Dissection of carotid artery will affect blood supply to brain

• A simple web-based simulator

Our Simulator

• Aims to be an adjunct to training of neurosurgeons

Shorten period of training

Understanding of procedure and risks involved

VRML world extended with Java EAI to provide simulation

The Simulator - Architecture

• Client-based systemDownload self-contained simulation to client

Web

Ser

ver

Bro

wse

r

download

Single download, no dependency on network

• Extend reality by multiple views

The Simulator - Virtual World

From the eye of the surgeon

From the eye of the needle electrode

Eye of the surgeon Eye of the needle

Java EAI

• Virtual planes

• Place landmarks

The Simulator - Simulating The Surgical Practice

The Simulator - Manipulating The Tools

• Controller

• Rotate and translateaccording to rules of surgical procedure

• Three VRML worldsco-ordinated through Java EAI

The Simulator - Hitting The Target

• Collision detection between

Only collision with viewer

objects not supported in VRML• Solution:

Detect collision with eye of the needle electrode

Success

Oops….

• Client-based WWW surgical training system is fast, cheap, …

• Collision detection between needle and multiple complex objects is efficient

Conclusion

• Various surgical tasks have been simulated

• Complexity versus ease of use ?