An interactive augmented reality software for facial reconstructive surgeries

Background and Objective: Surgical trainees need a lot of training and practice before being able to operate independently. The current approach of surgical education mainly involves didactic teaching and psychomotor training through physical models or real tissue. Due to the unavailability of physical resources and lack of objective ways of evaluation, there is a demand for developing alternative training methods for surgeons. In this paper, we present an application that provides additional training opportunities to surgical trainees in the field of facial reconstructive surgeries.Methods: We built a mobile augmented reality application that helps the user to visualize important concepts and experiment with different surgical plans for facial reconstructive surgeries. The application can overlay relaxed skin tension lines on a live video input or a patient's photo, which serve as bases for aligning a skin flap. A surgical trainee can interactively compare different skin flap design choices with estimated final scars on a photo of a patient. Data collection capability is also added to the application, and we performed a Monte Carlo experiment with simulated users (five classes of 100 users each) as an example of objectively measuring user performance.Results: The application can overlay relaxed skin tension lines on a patient's face in real time on a modern mobile device. Accurate overlays were achieved in over 91% as well as 84% and 88% out of 263 generated face images, depending on the method. Visual comparisons of the three overlay methods are presented on sample faces from different population groups. From the Monte Carlo experiment, we see that user actions in each class follow a normal distribution with a distinct set of parameters. Conclusions: This application can serve as a basis for teaching surgical trainees the fundamentals of different facial reconstructive procedures, especially concepts related to relaxed skin tension lines and skin flaps. It can objectively evaluate the performance of surgical trainees in a course. This setup focuses on illustrating the relationship between the orientation of skin flaps and relaxed skin tension lines, which is a prerequisite of minimizing scarring in patients in addition to good surgical techniques.