Simulation of minimally invasive procedures in virtual environments involves (1) the construction of 3D anatomical models from medical images, (2) modeling of tissue characteristics and behavior, (3) design of electromechanical devices for recording and displaying tissue properties, (4) graphical and haptic rendering of soft tissue behavior for simulating instrument-tissue interactions, and (5) design of simulation scenarios and training procedures. Until recently, the research groups working in this area have focused on a subset of these topics and in restricted application domains. The first component, the construction of anatomical models from medical images has been extensively covered in the literature and generic 3D anatomical models generated from Visible Man/Woman data are now available in the market through various sources. But our progress in understanding the behavior of living tissues, the design of mechanical devices for recording and simulation of tissue behavior, real time graphical and haptic rendering of soft tissue behavior, and the simulation principles for training is still inadequate. The particular questions that arise include:
 

• What are the important characteristics of living tissues that can be perceived by the trainee and which ones need to be included in our models?
• How to obtain tissue properties through in vivo measurements?
• Which degrees of freedom are more important to consider in designing force-reflecting robotic devices for simulating minimally invasive procedures?
• What programming and modeling techniques can we follow to run our physically based models in real-time?
• How to integrate haptic feedback into our simulators?
• How should we design the simulation scenarios to achieve our training goals?
• How can we measure training effectiveness?

  Cagatay Basdogan
  Massachusetts Institute of Technology

Presenters:

  Mandayam A. Srinivasan, MIT, (slides, pdf) 
  Mark Ottensmeyer, MIT (slides, www.ai.mit.edu/people/canuck/MMVR)
  Cagatay Basdogan, MIT, (slides, pdf)
  Thomas Krummel, Stanford

Time Interval: 1.00 pm – 5.15 pm, 
Date: Thursday, January  27, 2000
Location: Marriot Hotel, Newport Beach, CA
 

Sections:

Introduction and Overview (15 minutes)
Presenter: C. Basdogan 
Time Interval: 1.00 – 1.15 pm

1. Understanding and modeling biomechanical properties of living tissues (45 minutes)

• Principles of tissue mechanics
• Basic properties of living tissues and their measurement
• Tissue models and approximations
• Human perceptual issues as applied to medical simulation

2. Design of electromechanical devices for measurement and display (45 minutes)

• Design principles of robotic devices for measuring tissue properties
• Design principles of robotic devices for displaying tissue properties 

3. Simulation of Instrument-Tissue Interactions and System Integration (45 minutes)

• Collision detection and computational models of surgical instruments
• Physically-based modeling for simulating soft tissue behavior in real-time
• Haptic rendering of deformable objects
• Integration of hardware and software components for developing a simulator

4. Design of Simulation Scenarios and Training (45 minutes)

• Part-task versus team training environments
• Modeling and measuring human performance 
• Measurement of training effectiveness