Virtual Open Heart Surgery: Training Complex Surgical Procedures in Congenital Heart Disease

A new training tool for complex heart surgery. Morphologically accurate models of congenitally malformed hearts were reconstructed from 3D MRI data and integrated in graphical settings representing the surgical environment.

Enhanced Life
This is the first surgical simulator that fully utilizes the GPU to achieve a significant computational speedup. The physical simulation behind the simulator could not have achieved real-time convergence and interactivity by any known CPU approach, due to the size and complexity of heart morphology.

Goals
The advantages of virtual surgical training are (at least) two-fold:

1. It can illustrate various elements of difficult surgical procedures.

2. It can allow surgeons to rehearse these elements virtually.

In time, virtual surgery will become a natural supplement to and even replace parts of current surgical training, as training on artificial materials and/or animals in many ways "transfers" unfavorably to real procedures in patients. In the foreseeable future, new tools will take younger surgeons faster and more safely through their inevitable learning curves.

Innovations
The current implementation resolves a volumetric spring-mass-based physical simulation entirely on the GPU. The simulation state is visualised by the inner and outer surfaces of the heart in a resolution that is independent of the underlying simulation. Supported gestures include elastic tissue deformation by grabbing, cutting, and suturing with haptic feedback. The simulation achieves an overall frame rate of 30 Hz on a GeForce 7800 GTX when a surface of 135,000 faces is visualized based on deformation of an underlying spring-mass system of 20,000 nodes. In each frame, the physical simulation performs 15 iterations corresponding to 450 iterations per second. Force feedback is likewise provided at 450 Hz.

Vision
Using the GPU as a processor, simulations can now harvest the computational power that is necessary to simulate the deformation of complex morphology in real time. For the first time, surgeons can rehearse open-heart surgery interactively in a virtual environment. As a consequence, an entire new field of surgical education is emerging to help young surgeons accelerate their learning curve for the safety of patients.

SIGGRAPH 2006 attendees are invited to test their skills in closing a ventricular septal defect (a hole between the two main chambers of the heart).

Emerging Technologies Sketch

Contact
Thomas Sangild Sørensen
Centre for Advanced Visualisation and Interaction
University of Aarhus, Denmark
Sangild (at) cavi.dk

Contributors
Jesper Mosegaard
Dagur Ballisager
Bo Carstensen
Allan Rasmusson
University of Aarhus, Denmark