Wireless 3D Surgical Navigation and Tracking System With 100μm Accuracy Using Magnetic-Field Gradient-Based Localization
This paper describes a high-resolution 3D navigation and tracking system using magnetic field gradients, that can replace X-Ray fluoroscopy in high-precision surgeries. Monotonically varying magnetic fields in X, Y and Z directions are created in the field-of-view (FOV) to produce magnetic field gradients, which encode each spatial point uniquely. Highly miniaturized, wireless and battery-less devices, capable of measuring their local magnetic field, are designed to sense the gradient field. One such device can be attached to an implant inside the body and another to a surgical tool, such that both can simultaneously measure and communicate the magnetic field at their respective locations to an external receiver. The relative location of the two devices on a real-time display can enable precise surgical navigation without using X-Rays. A prototype device is designed consisting of a micro-chip fabricated in 65nm CMOS technology, a 3D magnetic sensor and an inductor-coil. Planar electromagnetic coils are designed for creating the 3D magnetic field gradients in a 20 × 20 × 10cm³ of scalable FOV. Unambiguous and orientation-independent spatial encoding is achieved by: (i) using the gradient in the total field magnitude instead of only the Z-component; and (ii) using a combination of the gradient fields to correct for the non-linearity and non-monotonicity in X and Y gradients. The resultant X and Y FOV yield ≥90% utilization of their respective coil-span. The system is tested in vitro to demonstrate a localization accuracy of <100 μm in 3D, the highest reported to the best of our knowledge.
© 2021 IEEE. Manuscript received January 27, 2021; revised March 10, 2021; accepted March 30, 2021. Date of publication April 5, 2021; date of current version July 30, 2021. This work was supported in part by the National Science Foundation under Grant 1823036, in part by the Rothenberg Innovation Initiative under Grant 101170, and in part by the Heritage Medical Research Institute. The authors acknowledge the contributions of M. Wang, S. Shah, W. Kuo, H. Sheng, A. Patil, K.-C. Chen, and N. Phoole from the MICS Laboratory; H. Davis from the Shapiro Laboratory; A. Khachaturian from the CHIC Laboratory; Dr. P.W. Goodwill, Dr. A.G. Siraki, Dr. J. Dorris, Dr. J. Kelly, and Dr. S. Nikzad for insightful discussions; Muse Semiconductor for Chip fabrication; the editors and the anonymous reviewers for their highly valuable comments and feedback.
Accepted Version - 09395486.pdf