Using Open Source Technologies to develop low cost Surgical Simulators

Shamyl B Mansoor, Zohaib Amjad, Asif Zafar, Dr

National University of Sciences and Technology, Holy Family Hospital

Introduction
Minimal Invasive Surgery, (MIS), is an advanced method performed by using instruments inserted through small keyhole incisions. In countries like Pakistan who have not completely adopted MIS, surgeons are trained for open surgery. In open surgery surgeons are used to handling things directly with their hands and instruments that are not confined to small spaces. Training of surgeons becomes a challenging prospect due to this paradigm shift. MIS requires the use of special skills by a surgeon which include skills like hand eye coordination, working in confined spaces and working with lack of depth perception. Dexterity loss takes place which should be compensated by repetitive training. This repetitive training is usually possible by using Simulators.

Objective
Commercial simulators like LapSim, LapMentor and ProMIS are available that are used for training of MIS techniques. These simulators are very costly and generally unaffordable for countries like Pakistan which have very limited budgets for public health and education. In this project our objective is to develop a cost effective local solution for Pakistan by using open source simulation engines.

Methodology
Generally a simulator consists of a simulation engine, a collision pipeline, a user interface and visualization methods. We have used SOFA (Simulation Open Framework Architecture) an open source simulation engine to develop our simulator system. This has allowed us to develop rapidly rather than developing everything from scratch. In order to train the surgeons we have divided the simulator into three kinds of trainings. Basic, General Surgery and Gynecology training modules.

Figures (Clockwise) 1a: Lifting and burning, 1b: Grasping and placing, 1c: Peg transfer, 1d: Suturing
The first step in modeling a training exercise requires developing visual models of objects. These objects can be pegs or donuts like in figure 1c or a flexible vein model of 1a. This modeling is usually done using 3d modeling tool. In the second step physics of these models is implemented. We implement this by using scene graphs in SOFA. Finally when all objects are modeled the whole scene is then modeled as an exercise.

Discussion
We have used open source tools for development of the simulator system. This has reduced the cost of development significantly. The simulation engine is absolutely free and the only cost is in terms of development and modeling of training exercises. By collaborating with a team of surgeons we are also able to validate our training system. Apart from the training exercises which are based on the Fundamentals of Laparoscopic Surgery (FLS) curriculum we are also implementing an intelligent evaluation method in the simulator. The method uses data from expert surgeons’ performances and analyzes this data with that of a trainee surgeon. Based on this analysis a score is generated which tells the trainee of how well he has performed.

Conclusion
The system currently developed has features like instrument navigation, handling, camera navigation, tying knots and performing basic training exercises. In the next 12 months we will be implementing more complex training exercises.

Session: Podium Presentation

Program Number: ET008