Assessment of Position Repeatability Error in an Electromagnetic Tracking System for Surgical Navigation In this paper we present a study of the repeatability of an innovative electromagnetic tracking system (EMTS) for surgical navigation, developed to overcome the state of the art of current commercial systems, allowing for the placement of the magnetic field generator far from the operating table. Previous studies led to the development of a preliminary EMTS prototype. Several hardware improvements are described, which result in noise reduction in both signal generation and the measurement process, as shown by experimental tests. The analysis of experimental results has highlighted the presence of drift in voltage components, whose effect has been quantified and related to the variation of the sensor position. Repeatability in the sensor position measurement is evaluated by means of the propagation of the voltage repeatability error, and the results are compared with the performance of the Aurora system (which represents the state of the art for EMTS for surgical navigation), showing a repeatability error about ten times lower. Finally, the proposed improvements aim to overcome the limited operating distance between the field generator and electromagnetic (EM) sensors provided by commercial EM tracking systems for surgical applications and seem to provide a not negligible technological advantage.

Design and validation of a sixantenna WPT system with tracking capabilites for biomedical devices Reliable powering of implantable medical devices is a key requirement for the development of eversosmall sensors and actuators. The difficulty of this task becomes even greater when the device is meant to travel inside the human body. This paper presents a 2 GHz RF WPT system capable of tracking an implantable device and maximizing the amount of power transferred to it along its path. Measurements and simulations were performed to validate the system, and the use of tracking increased the amount of available power for the implant along its path in all the studied points comparatively to the scenario where no tracking was used. This technology presents itself as a promising stepping stone towards batteryless implantable medical devices.