A Novel Electromagnetic Positioning Prototype System With Simplified Receiver for Interventional Surgery Application

Abstract

To meet the need of 3D positioning of surgical instru-ment in interventional surgery and the requirement of smaller size sensor for the narrow blood vessels, a new electromagnetic posi-tioning model is proposed with simplified receiver. Based on the electromagnetic theory and geometry principle, the electromag-netic field transmitter with groups of three orthogonal coils and the simplified receiver with smaller size than existing sensors are designed. Then, using Biot-Savart Law, the distance between re-ceiving end and geometric center of orthogonal coils is calculated, and the spatial coordinate of receiving end is computed with the spherical intersection formula. To further reduce the positioning error, a two-round accuracy improvement algorithm is designed for selecting the optimal topology of coil groups at the transmitter end and fitting correction of the calculated distance. We imple-ment the prototype system and perform both simulation experi-ments and actual experiments. The results show that our proposed new electromagnetic positioning method with simplified receiver has higher accuracy and stronger stability, compared with the tra-ditional positioning approach of three-coil transmitter and three-coil receiver.