An Optimized Switching Integrated Transmitter Pad for Generating Orthogonal H-Field Components to Localize Implanted Devices

Abstract

This paper proposes an optimized switching integrated transmitter to generate highly non-uniform magnetic field (H-field) components for near-field localization applications. The localization accuracy of a magnetic-based localization system depends on the degree of non-uniformity present in the H-field distribution. Targeting this, several state-of-the-art designs presented eight spatially distributed transmitter structures. However, the absence of required H-field components at several receiver positions resulted in poor localization performance. To overcome this problem, an overlapping coil transmitter structure has been proposed in this work that spreads the H-field components at the receiver region. Further optimization of the transmitter coil design parameters is performed analytically to accomplish a highly non-uniform H-field at the receiver location and miniaturize the transmitter size. A time-divisional approach has been exploited and realized using a switching technique to acquire the required voltage samples at the receiver. The proposed transmitter is realized using a high-frequency Litz wire, and the switching is performed by adopting DPDT switches. The fabricated prototype is experimentally verified, and the measured results show a good agreement with the analytical result. This demonstrates the potential of the proposed transmitter for near-field localization applications such as the localization of biomedical implants, wireless endoscopy capsules, etc.