SimQuest implemented and assessed numerous collision detection and re - sponse approaches from the literature as well as commercial (PhysX) and open source (Bullet), and ultimately developed its own approach that supports continuous collision detection combined with force and linear complementarity geometric constraints which have been refined to resolve hundreds of simultaneous contacts of many types, including constraints that conflict with one another, e.g. pressing a suture into the tissue surface with a tool.
The system provides force/torque feedback from the tools interacting with the simulated surgical scene through a multi-rate approach that provides effective feel independent of the varying computational load on the multiple processor cores. This information is relayed to haptic devices that provide simultaneous two-handed 7 DOF interaction.
The simulator can extract metrics for objective assessment of proficiency, from geometric measures of tool-to-tissue activity as well as kinetic, force-based monitoring of interaction, by exposing the internal variables that reflect the ongoing physics state during the simulation as well as specific geometric measures of the tool-tissue interaction in the surgical scenario so that they are accessible via the Lua scripting language.
The system creates scenario-based surgical training content using a collection of software tools that were developed to form the equivalent of the classic computer gaming tool chain. By using these tools, new scenarios can be developed without having to write code with the resulting set of XML-based data files used to define the simulation when the program starts.
The didactic learning interface is implemented in HTML5 and constructed such that its display automatically adapts to whatever display device is used.
Where it Stands
The Open Incision Surgery Simulator system has been developed to the point of assessing the transfer of training for an initial scenario; plans for expansion of this content and further development of the system as a commercial platform are underway.
SimQuest is currently approaching its first hands-on assessment of the simulator at Old Dominion University in Norfolk, VA. The company plans to use the results of this assessment to update the system before moving into the production phase. In the future, the company hopes to gain validation from the American College of Surgeons as a recommended addition to the Surgical Skills Curriculum.
For more information about the Open Incision Surgery Simulator, visit http://info.hotims.com/34460-160.