Wireless Electromagnetic Tracking System for Wireless Capsule Endoscope

Electromagnetic tracking (EMT) is widely employed in image-guided surgical procedures, enabling precise tracking of the position and orientation of medical instruments. However, the traditional EMT system needs wires to be led out from the transmitting side to the receiving side, rendering it unsuitable for in vivo biomedical implants. This study proposes a wireless EMT system tailored for the wireless capsule endoscope (WCE) application, which includes: 1) elucidation of fundamental comparison between “wired” EMT and “wireless” EMT; 2) devising a corresponding wireless EMT algorithm; and 3) a small-sized, low-power hardware architecture for the receiving side of EMT. The receiving circuit is about the size of the capsule, and consumes 4.73 mW excluding the wireless communication module. Experiment results show the effectiveness of the proposed wireless EMT. Within a tracking region of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$20\times 15\times 13$ </tex-math></inline-formula> cm3, the position error is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.24~\pm ~0.88$ </tex-math></inline-formula> mm and the orientation error is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.95~\pm ~0.79^{\circ }$ </tex-math></inline-formula>, with an update rate of 1 Hz.