A virtual platform for real-time performance analysis of electromagnetic tracking systems for surgical navigation

<p class="Abstract">Electromagnetic Tracking Systems (EMTSs) are widely used in surgical navigation, allowing to improve the outcome of diagnosis and surgical interventions, by providing the surgeon with real-time position of surgical instruments during medical procedures. However, particular effort was dedicated to the development of efficient and robust algorithms, to obtain an accurate estimation of the instrument position for distances from the magnetic field generator beyond 0.5 m. Indeed, the main goal is to improve the limited range of current commercial systems, which strongly affects the freedom of movement of the medical team. Studies are currently being conducted to optimize the magnetic field generator configuration (both geometrical arrangements and electrical properties) since it affects tracking accuracy. In this paper, we propose a virtual platform for assessing the performance of EMTSs for surgical navigation, providing real-time results and statistics, and allowing to track instruments both in real and simulated environments. Simulations and experimental tests are performed to validate the proposed virtual platform, by employing it to assess the performance of a real EMTS. The platform offers a real-time tool to analyze EMTS components and field generator configurations, for a deeper understanding of EMTS technology, thus supporting engineers during system design and characterization.</p>

ALTERNATING MAGNETIC FIELD GENERATOR FOR THREE-DIMENSIONAL POSITION TRACKING OF MEDICAL TREATMENT EQUIPMENT FOR TRAINING

In recent years, the incidence of cardiovascular disease is high due to the aging population and westernization of dietary habits, what encourages researching new methods. Most cardiovascular procedures use the catheter. In the procedure using a catheter, a long time of training is required to lower the procedure risk. So, a medical training simulator is being developed. In the actual procedure, the position of the catheter is confirmed by a C-arm using X-ray, but there is a risk of over exposure to radiation if the X-ray device is used until training. To solve this problem, in previous studies, the position of the catheter was tracked using a permanent magnet. However, the method of permanent magnet has a high error value due to the shape of the external magnetic flux density and the interference of environmental magnetic field. In this paper, an alternating magnetic field generator is proposed for 3D position tracking of medical equipment for training. An electromagnet with an optimal shape was designed through finite element analysis. The designed electromagnet is implemented and tested to confirm the performance. Through the location tracking experiment, an equation to estimate the distance between the electromagnet and the Hall sensor in 3D space was derived by linear regression recursive method. Through the derived equation, it was possible to track the position of the electromagnet at any position in the 3D space. Unlike previous studies using permanent magnets, the proposed alternating magnetic field generator has an isotropic shape with an external magnetic flux density according to the same distance. So, it is possible to reduce errors in position and distance, and minimize the effect of environmental magnetic fields by using an alternating magnetic field.