Simulation Taskflow

When using SEE++ to model and simulate eye motility disorders, a certain simulation task flow can be defined in order to perform simulation and evaluation of model predictions.

simulation taskflow
  1. Parameterization with patient data: One main goal of SEE++ is to give close-to-reality predictions of a patient-specific situation. In this first step of the simulation task flow, model values will be based directly on the patient. Parameters can be modified such as globe radius, cornea radius, muscle lengths, insertions, tendons etc. At the same time, general data are entered, like patient name, description or diagnosis.

  2. Simulation of pathology: During the simulation of a pathology, model parameters are changed in such a way that the resulting model predictions correspond to measured values of the patient, as closely as possible. A model prediction is the simulation of a clinical Hess-Lancaster test, whereby the representation for right and/or left fixation is used. By determination of the Hess-Lancaster data of the patient, these values can be compared to simulated data to find whether the simulation corresponds to the pathology of the patient. Also the 3D representation of the patient offers additional support regarding the evaluation of simulation predictions.

  3. Comparison of simulation results with patient data: This comparison refers to the Hess-Lancaster investigation already mentioned, whereby the process of comparing can also serve as a verification of the diagnosis. Thus, this step determines whether the simulation result agrees sufficiently with the measured patient data. This, at the same time, offers a basis for the simulation of treatment by interactive virtual surgery of the modeled pathology.

  4. Simulation of surgery: Here the actual operation is simulated by interactively modifying different model parameters using the mouse within the 3D representation. Points of reference support orientation and the dosage of the surgery performed. Furthermore, different surgery techniques are available such as transposition and tangential repositioning of muscle insertions. Muscle force and innervation parameters are changed manually in the program so that they correspond to a comparable surgical procedure. For example, a muscle resection can be accomplished by changing the value of the parameter for muscle length. The 3D model visualizes these changes immediately after confirmation of entered values.

  5. Evaluation of results: According to step 3, a repeated comparison of simulation results is performed. On the basis of the binocular Hess-Lancaster test, the outcome of a surgery can be judged regarding the correction of a pathological situation, and whether it is still necessary to apply additional changes (simulation trials).

  6. Simulation result: The simulation result represents the last condition of all model parameters in the simulation task flow. The system enables the user to assign and archive scenarios to a patient. Thereby, the results of different simulations may be compared and e.g. simulation strategies can be developed. Each scenario stores any step of a treatment of a patient and can later be recalled in textual or graphic ways.