The Development of a Virtual Simulator for a Novel Design Non-Permanent Magnetic Needle Based Eye Anesthesia Training System

Ophthalmic anesthesia plays a crucial role in eye surgery. However, the conventional practice of this process is a blind procedure, in which a needle is inserted blindly into the cadaver. This paper introduces a needle tip tracking system for ophthalmic anesthesia training focusing on the Retrobulbar block procedure. The study presents a development in a prototyped system using Hall effect sensor arrays to track a 5D magnetized needle tip (X, Y, Z, theta, phi). The orbital structure is fabricated with embedded Hall effect sensors. The extended Kalman filter and least square method are developed to select the observation model from multiple training sets and to estimate the needle tip coordinates. The robotic manipulator (ABB YUMI) is used to model the training set between the distance and the initial angle of the magnetized needle. The developed system provides the needle tip position with an RMS of Euclidean distance error up to 1.7398 +/- 0.5288 mm. As a result, the system is capable of providing the needle tip positions with an acceptable error comparing the system's accuracy with the size of the retrobulbar target space and important anatomies.