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

To meet the need of 3-D positioning of surgical instrument in interventional surgery and the requirement of smaller size sensor for the narrow blood vessels, a new electromagnetic positioning model is proposed with a simplified receiver. Based on the electromagnetic theory and geometry principle, the electromagnetic field transmitter with groups of three orthogonal coils and the simplified receiver with a smaller size than existing sensors are designed. Then, using the Biot–Savart law, the distance between receiving 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 implement the prototype system and perform both simulation experiments and actual experiments. The results show that our proposed new electromagnetic positioning method with a simplified receiver has higher accuracy and stronger stability, compared with the traditional positioning approach of three-coil transmitter and three-coil receiver.